gfs2: rgrp: fix kernel-doc warnings

Fix kernel-doc warnings found when using "W=1".

rgrp.c:162: warning: missing initial short description on line:
* gfs2_bit_search
rgrp.c:1200: warning: Function parameter or member 'gl' not described in 'gfs2_rgrp_go_instantiate'
rgrp.c:1200: warning: Excess function parameter 'gh' description in 'gfs2_rgrp_go_instantiate'
rgrp.c:1970: warning: missing initial short description on line:
* gfs2_rgrp_used_recently

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Fix kernel NULL pointer dereference in gfs2_rgrp_dump

Syzkaller has reported a NULL pointer dereference when accessing
rgd->rd_rgl in gfs2_rgrp_dump(). This can happen when creating
rgd->rd_gl fails in read_rindex_entry(). Add a NULL pointer check in
gfs2_rgrp_dump() to prevent that.

Reported-and-tested-by: syzbot+da0fc229cc1ff4bb2e6d@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=da0fc229cc1ff4bb2e6d
Fixes: 72244b6bc752 ("gfs2: improve debug information when lvb mismatches are found")
Signed-off-by: Osama Muhammad <osmtendev@gmail.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Get rid of gfs2_alloc_blocks generation parameter

Get rid of the generation parameter of gfs2_alloc_blocks(): we only ever
set the generation of the current inode while creating it, so do so
directly.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Update rl_unlinked before releasing rgrp lock

Function gfs2_free_di was changing the rgrp lvb count of unlinked
dinodes after the lock was released. This patch moves it inside the
lock.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Split the two kinds of glock "delete" work

Function delete_work_func() is used for two purposes:

* to immediately try to evict the glock's inode, and

* to verify after a little while that the inode has been deleted as
expected, and didn't just get skipped.

These two operations are not separated very well, so introduce two new
glock flags to improved that. Split gfs2_queue_delete_work() into
gfs2_queue_try_to_evict and gfs2_queue_verify_evict().

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Make go_instantiate take a glock

Make go_instantiate take a glock instead of a glock holder as its argument:
this handler is supposed to instantiate the object associated with the glock.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Minor gfs2_glock_nq_m cleanup

Add state and flags arguments to gfs2_rlist_alloc() to make it somewhat more
obvious which state and flags an rlist uses. With that, stop knocking off
flags in gfs2_glock_nq_m() and its nq_m_sync() helper that are never set in the
first place.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Return more useful errors from gfs2_rgrp_send_discards()

The bug that 27ca8273f ("gfs2: Make sure FITRIM minlen is rounded up to
fs block size") fixes was a little confusing as the user saw
"Input/output error" which masked the -EINVAL that sb_issue_discard()
returned.

sb_issue_discard() can fail for various reasons, so we should return its
return value from gfs2_rgrp_send_discards() to avoid all errors being
reported as IO errors.

This improves error reporting for FITRIM and makes no difference to the
-o discard code path because the return value from
gfs2_rgrp_send_discards() gets thrown away in that case (and the option
switches off). Presumably that's why it was ok to just return -EIO in
the past, before FITRIM was implemented.

Tested with xfstests.

Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

block: add a bdev_discard_granularity helper

Abstract away implementation details from file systems by providing a
block_device based helper to retrieve the discard granularity.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> [drbd]
Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Link: https://lore.kernel.org/r/20220415045258.199825-26-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: remove QUEUE_FLAG_DISCARD

Just use a non-zero max_discard_sectors as an indicator for discard
support, similar to what is done for write zeroes.

The only places where needs special attention is the RAID5 driver,
which must clear discard support for security reasons by default,
even if the default stacking rules would allow for it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> [drbd]
Acked-by: Jan Höppner <hoeppner@linux.ibm.com> [s390]
Acked-by: Coly Li <colyli@suse.de> [bcache]
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220415045258.199825-25-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

gfs2: Make sure FITRIM minlen is rounded up to fs block size

Per fstrim(8) we must round up the minlen argument to the fs block size.
The current calculation doesn't take into account devices that have a
discard granularity and requested minlen less than 1 fs block, so the
value can get shifted away to zero in the translation to fs blocks.

The zero minlen passed to gfs2_rgrp_send_discards() then allows
sb_issue_discard() to be called with nr_sects == 0 which returns -EINVAL
and results in gfs2_rgrp_send_discards() returning -EIO.

Make sure minlen is never < 1 fs block by taking the max of the
requested minlen and the fs block size before comparing to the device's
discard granularity and shifting to fs blocks.

Fixes: 076f0faa764ab ("GFS2: Fix FITRIM argument handling")
Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: gfs2_setattr_size error path fix

When gfs2_setattr_size() fails, it calls gfs2_rs_delete(ip, NULL) to get
rid of any reservations the inode may have. Instead, it should pass in
the inode's write count as the second parameter to allow
gfs2_rs_delete() to figure out if the inode has any writers left.

In a next step, there are two instances of gfs2_rs_delete(ip, NULL) left
where we know that there can be no other users of the inode. Replace
those with gfs2_rs_deltree(&ip->i_res) to avoid the unnecessary write
count check.

With that, gfs2_rs_delete() is only called with the inode's actual write
count, so get rid of the second parameter.

Fixes: a097dc7e24cb ("GFS2: Make rgrp reservations part of the gfs2_inode structure")
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: assign rgrp glock before compute_bitstructs

Before this patch, function read_rindex_entry called compute_bitstructs
before it allocated a glock for the rgrp. But if compute_bitstructs found
a problem with the rgrp, it called gfs2_consist_rgrpd, and that called
gfs2_dump_glock for rgd->rd_gl which had not yet been assigned.

read_rindex_entry
compute_bitstructs
gfs2_consist_rgrpd
gfs2_dump_glock <---------rgd->rd_gl was not set.

This patch changes read_rindex_entry so it assigns an rgrp glock before
calling compute_bitstructs so gfs2_dump_glock does not reference an
unassigned pointer. If an error is discovered, the glock must also be
put, so a new goto and label were added.

Reported-by: syzbot+c6fd14145e2f62ca0784@syzkaller.appspotmail.com
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: remove RDF_UPTODATE flag

The new GLF_INSTANTIATE_NEEDED flag obsoletes the old rgrp flag
GFS2_RDF_UPTODATE, so this patch replaces it like we did with inodes.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: fix GL_SKIP node_scope problems

Before this patch, when a glock was locked, the very first holder on the
queue would unlock the lockref and call the go_instantiate glops function
(if one existed), unless GL_SKIP was specified. When we introduced the new
node-scope concept, we allowed multiple holders to lock glocks in EX mode
and share the lock.

But node-scope introduced a new problem: if the first holder has GL_SKIP
and the next one does NOT, since it is not the first holder on the queue,
the go_instantiate op was not called. Eventually the GL_SKIP holder may
call the instantiate sub-function (e.g. gfs2_rgrp_bh_get) but there was
still a window of time in which another non-GL_SKIP holder assumes the
instantiate function had been called by the first holder. In the case of
rgrp glocks, this led to a NULL pointer dereference on the buffer_heads.

This patch tries to fix the problem by introducing two new glock flags:

GLF_INSTANTIATE_NEEDED, which keeps track of when the instantiate function
needs to be called to "fill in" or "read in" the object before it is
referenced.

GLF_INSTANTIATE_IN_PROG which is used to determine when a process is
in the process of reading in the object. Whenever a function needs to
reference the object, it checks the GLF_INSTANTIATE_NEEDED flag, and if
set, it sets GLF_INSTANTIATE_IN_PROG and calls the glops "go_instantiate"
function.

As before, the gl_lockref spin_lock is unlocked during the IO operation,
which may take a relatively long amount of time to complete. While
unlocked, if another process determines go_instantiate is still needed,
it sees GLF_INSTANTIATE_IN_PROG is set, and waits for the go_instantiate
glop operation to be completed. Once GLF_INSTANTIATE_IN_PROG is cleared,
it needs to check GLF_INSTANTIATE_NEEDED again because the other process's
go_instantiate operation may not have been successful.

Functions that previously called the instantiate sub-functions now call
directly into gfs2_instantiate so the new bits are managed properly.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: change go_lock to go_instantiate

Before this patch, the go_lock glock operations (glops) did not do
any actual locking. They were used to instantiate objects, like reading
in dinodes and rgrps from the media.

This patch renames the functions to go_instantiate for clarity.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Switch some BUG_ON to GLOCK_BUG_ON for debug

In rgrp.c, there are several places where it does BUG_ON. This tells us
the call stack but nothing more, which is not very helpful.
This patch switches them to GLOCK_BUG_ON which also prints the glock,
its holders, and many of the rgrp values, which will help us debug
problems in the future.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: move GL_SKIP check from glops to do_promote

Before this patch, each individual "go_lock" glock operation (glop)
checked the GL_SKIP flag, and if set, would skip further processing.

This patch changes the logic so the go_lock caller, function go_promote,
checks the GL_SKIP flag before calling the go_lock op in the first place.
This avoids having to unnecessarily unlock gl_lockref.lock only to
re-lock it again.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: remove redundant check in gfs2_rgrp_go_lock

Before this patch, function gfs2_rgrp_go_lock checked if GL_SKIP and
ar_rgrplvb were both true. However, GL_SKIP is only set for rgrps if
ar_rgrplvb is true (see gfs2_inplace_reserve). This patch simply removes
the redundant check.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Fix a number of kernel-doc warnings

Building the kernel with W=1 results in a number of kernel-doc warnings
like incorrect function names and parameter descriptions. Fix those,
mostly by adding missing parameter descriptions, removing left-over
descriptions, and demoting some less important kernel-doc comments into
regular comments.

Originally proposed by Lee Jones; improved and combined into a single
patch by Andreas.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Silence possible null pointer dereference warning

In gfs2_rbm_find, rs is always NULL when minext is NULL, so
gfs2_reservation_check_and_update will never be called on a NULL minext.
This isn't innediately obvious though, so also check for a NULL minext
for better code readability.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Use resource group glock sharing

This patch takes advantage of the new glock holder sharing feature for
resource groups. We have already introduced local resource group
locking in a previous patch, so competing accesses of local processes
are already under control.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Add local resource group locking

Prepare for treating resource group glocks as exclusive among nodes but
shared among all tasks running on a node: introduce another layer of
node-specific locking that the local tasks can use to coordinate their
accesses.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Add per-reservation reserved block accounting

Add a rs_reserved field to struct gfs2_blkreserv to keep track of the number of
blocks reserved by this particular reservation, and a rd_reserved field to
struct gfs2_rgrpd to keep track of the total number of reserved blocks in the
resource group. Those blocks are exclusively reserved, as opposed to the
rs_requested / rd_requested blocks which are tracked in the reservation tree
(rd_rstree) and which can be stolen if necessary.

When making a reservation with gfs2_inplace_reserve, rs_reserved is set to
somewhere between ap->min_target and ap->target depending on the number of free
blocks in the resource group. When allocating blocks with gfs2_alloc_blocks,
rs_reserved is decremented accordingly. Eventually, any reserved but not
consumed blocks are returned to the resource group by gfs2_inplace_release.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Rename rs_{free -> requested} and rd_{reserved -> requested}

We keep track of what we've so far been referring to as reservations in
rd_rstree: the nodes in that tree indicate where in a resource group we'd
like to allocate the next couple of blocks for a particular inode. Local
processes take those as hints, but they may still "steal" blocks from those
extents, so when actually allocating a block, we must double check in the
bitmap whether that block is actually still free. Likewise, other cluster
nodes may "steal" such blocks as well.

One of the following patches introduces resource group glock sharing, i.e.,
sharing of an exclusively locked resource group glock among local processes to
speed up allocations. To make that work, we'll need to keep track of how many
blocks we've actually reserved for each inode, so we end up with two different
kinds of reservations.

Distinguish these two kinds by referring to blocks which are reserved but may
still be "stolen" as "requested". This rename also makes it more obvious that
rs_requested and rd_requested are strongly related.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Don't search for unreserved space twice

If gfs2_inplace_reserve has chosen a resource group but it couldn't make a
reservation there, there are too many other reservations in that resource
group. In that case, don't even try to respect existing reservations in
gfs2_alloc_blocks.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Only pass reservation down to gfs2_rbm_find

Only pass the current reservation down to gfs2_rbm_find rather than the entire
inode; we don't need any of the other information.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Also reflect single-block allocations in rgd->rd_extfail_pt

Pass a non-NULL minext to gfs2_rbm_find even for single-block allocations. In
gfs2_rbm_find, also set rgd->rd_extfail_pt when a single-block allocation
fails in a resource group: there is no reason for treating that case
differently. In gfs2_reservation_check_and_update, only check how many free
blocks we have if more than one block is requested; we already know there's at
least one free block.

In addition, when allocating N blocks fails in gfs2_rbm_find, we need to set
rd_extfail_pt to N - 1 rather than N: rd_extfail_pt defines the biggest
allocation that might still succeed.

Finally, reset rd_extfail_pt when updating the resource group statistics in
update_rgrp_lvb, as we already do in gfs2_rgrp_bh_get.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Set GBF_FULL flags when reading resource group

When reading a resource group from disk or when receiving the resource group
statistics from a Lock Value Block (LVB), set/clear the GBF_FULL flags of all
bitmaps in that resource group according to whether or not the resource group
is full.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Don't clear GBF_FULL flags in rs_deltree

Removing a reservation doesn't make any actual space available, so don't clear
the GBF_FULL flags in that case. Otherwise, we'll only spend more time
scanning the bitmaps unnecessarily.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

Revert "gfs2: Don't reject a supposedly full bitmap if we have blocks reserved"

This reverts commit e79e0e1428188b24c3b57309ffa54a33c4ae40c4.

It turns out that we're only setting the GBF_FULL flag of a bitmap if we've
been scanning from the beginning of the bitmap until the end and we haven't
found a single free block, and we're not skipping reservations in that process,
either. This means that in gfs2_rbm_find, we can always skip bitmaps with the
GBF_FULL flag set.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Minor gfs2_inplace_reserve cleanup

Clean up the reservation size computation logic in gfs2_inplace_reserve a
little.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Get rid of unnecessary variable in gfs2_alloc_blocks

Variable ndata is only used inside "if (!dinode)", so it can be replaced
entirely with *nblocks.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Only use struct gfs2_rbm for bitmap manipulations

GFS2 uses struct gfs2_rbm to represent a filesystem block number as a
bit position within a resource group. This representation is used in
the bitmap manipulation code to prevent excessive conversions between
block numbers and bit positions, but also in struct gfs2_blkreserv which
is part of struct gfs2_inode, to mark the start of a reservation. In
the inode, the bit position representation makes less sense: first, the
start position is used as a block number about as often as a bit
position; second, the bit position representation makes the code
unnecessarily complicated and difficult to read.

Therefore, change struct gfs2_blkreserv to represent the start of a
reservation as a block number instead of a bit position. (This requires
keeping track of the resource group in gfs2_blkreserv separately.) With
that change, various things can be slightly simplified, and struct
gfs2_rbm can be moved to rgrp.c.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Turn gfs2_rbm_incr into gfs2_rbm_add

Change gfs2_rbm_incr to advance an rbm by a given number of blocks. Use that
in gfs2_reservation_check_and_update to save a gfs2_rbm_to_block ->
gfs2_rbm_from_block round trip.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: check for empty rgrp tree in gfs2_ri_update

If gfs2 tries to mount a (corrupt) file system that has no resource
groups it still tries to set preferences on the first one, which causes
a kernel null pointer dereference. This patch adds a check to function
gfs2_ri_update so this condition is detected and reported back as an
error.

Reported-by: syzbot+e3f23ce40269a4c9053a@syzkaller.appspotmail.com
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: fix possible reference leak in gfs2_check_blk_type

In the fail path of gfs2_check_blk_type, forgetting to call
gfs2_glock_dq_uninit will result in rgd_gh reference leak.

Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: check for live vs. read-only file system in gfs2_fitrim

Before this patch, gfs2_fitrim was not properly checking for a "live" file
system. If the file system had something to trim and the file system
was read-only (or spectator) it would start the trim, but when it starts
the transaction, gfs2_trans_begin returns -EROFS (read-only file system)
and it errors out. However, if the file system was already trimmed so
there's no work to do, it never called gfs2_trans_begin. That code is
bypassed so it never returns the error. Instead, it returns a good
return code with 0 work. All this makes for inconsistent behavior:
The same fstrim command can return -EROFS in one case and 0 in another.
This tripped up xfstests generic/537 which reports the error as:

+fstrim with unrecovered metadata just ate your filesystem

This patch adds a check for a "live" (iow, active journal, iow, RW)
file system, and if not, returns the error properly.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Free rd_bits later in gfs2_clear_rgrpd to fix use-after-free

Function gfs2_clear_rgrpd calls kfree(rgd->rd_bits) before calling
return_all_reservations, but return_all_reservations still dereferences
rgd->rd_bits in __rs_deltree. Fix that by moving the call to kfree below the
call to return_all_reservations.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Eliminate gl_vm

The gfs2_glock structure has a gl_vm member, introduced in commit 7005c3e4ae428
("GFS2: Use range based functions for rgrp sync/invalidation"), which stores
the location of resource groups within their address space. This structure is
in a union with iopen glock specific fields. It was introduced because at
unmount time, the resource group objects were destroyed before flushing out any
pending resource group glock work, and flushing out such work could require
flushing / truncating the address space.

Since commit b3422cacdd7e6 ("gfs2: Rework how rgrp buffer_heads are managed"),
any pending resource group glock work is flushed out before destroying the
resource group objects. So the resource group objects will now always exist in
rgrp_go_sync and rgrp_go_inval, and we now simply compute the gl_vm values
where needed instead of caching them. This also eliminates the union.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Wipe jdata and ail1 in gfs2_journal_wipe, formerly gfs2_meta_wipe

Before this patch, when blocks were freed, it called gfs2_meta_wipe to
take the metadata out of the pending journal blocks. It did this mostly
by calling another function called gfs2_remove_from_journal. This is
shortsighted because it does not do anything with jdata blocks which
may also be in the journal.

This patch expands the function so that it wipes out jdata blocks from
the journal as well, and it wipes it from the ail1 list if it hasn't
been written back yet. Since it now processes jdata blocks as well,
the function has been renamed from gfs2_meta_wipe to gfs2_journal_wipe.

New function gfs2_ail1_wipe wants a static view of the ail list, so it
locks the sd_ail_lock when removing items. To accomplish this, function
gfs2_remove_from_journal no longer locks the sd_ail_lock, and it's now
the caller's responsibility to do so.

I was going to make sd_ail_lock locking conditional, but the practice is
generally frowned upon. For details, see: https://lwn.net/Articles/109066/

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Fix NULL pointer dereference in gfs2_rgrp_dump

When an rindex entry is found to be corrupt, compute_bitstructs() calls
gfs2_consist_rgrpd() which calls gfs2_rgrp_dump() like this:

gfs2_rgrp_dump(NULL, rgd->rd_gl, fs_id_buf);

gfs2_rgrp_dump then dereferences the gl without checking it and we get

BUG: KASAN: null-ptr-deref in gfs2_rgrp_dump+0x28/0x280

because there's no rgrp glock involved while reading the rindex on mount.

Fix this by changing gfs2_rgrp_dump to take an rgrp argument.

Reported-by: syzbot+43fa87986bdd31df9de6@syzkaller.appspotmail.com
Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Turn gl_delete into a delayed work

This requires flushing delayed work items in gfs2_make_fs_ro (which is called
before unmounting a filesystem).

When inodes are deleted and then recreated, pending gl_delete work items would
have no effect because the inode generations will have changed, so we can
cancel any pending gl_delete works before reusing iopen glocks.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: don't lock sd_log_flush_lock in try_rgrp_unlink

In function try_rgrp_unlink, we added a temporary lock of the
sd_log_flush_lock while searching the bitmaps. This protected us from
problems in which dinodes being freed were still in a state of flux
because the rgrp was in an active transaction. It was a kludge.
Now that we've straightened out the code for inode eviction, deletes,
and all the recovery mess, we no longer need this kludge.
This patch removes it, and should improve performance.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: Split gfs2_rsqa_delete into gfs2_rs_delete and gfs2_qa_put

Keeping reservations and quotas separate helps reviewing the code.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: Change inode qa_data to allow multiple users

Before this patch, multiple users called gfs2_qa_alloc which allocated
a qadata structure to the inode, if quotas are turned on. Later, in
file close or evict, the structure was deleted with gfs2_qa_delete.
But there can be several competing processes who need access to the
structure. There were races between file close (release) and the others.
Thus, a release could delete the structure out from under a process
that relied upon its existence. For example, chown.

This patch changes the management of the qadata structures to be
a get/put scheme. Function gfs2_qa_alloc has been changed to gfs2_qa_get
and if the structure is allocated, the count essentially starts out at
1. Function gfs2_qa_delete has been renamed to gfs2_qa_put, and the
last guy to decrement the count to 0 frees the memory.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: eliminate gfs2_rsqa_alloc in favor of gfs2_qa_alloc

Before this patch, multiple callers called gfs2_rsqa_alloc to force
the existence of a reservations structure and a quota data structure
if needed. However, now the reservations are handled separately, so
the quota data is only the quota data. So we eliminate the one in
favor of just calling gfs2_qa_alloc directly.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: Rework how rgrp buffer_heads are managed

Before this patch, the rgrp code had a serious problem related to
how it managed buffer_heads for resource groups. The problem caused
file system corruption, especially in cases of journal replay.

When an rgrp glock was demoted to transfer ownership to a
different cluster node, do_xmote() first calls rgrp_go_sync and then
rgrp_go_inval, as expected. When it calls rgrp_go_sync, that called
gfs2_rgrp_brelse() that dropped the buffer_head reference count.
In most cases, the reference count went to zero, which is right.
However, there were other places where the buffers are handled
differently.

After rgrp_go_sync, do_xmote called rgrp_go_inval which called
gfs2_rgrp_brelse a second time, then rgrp_go_inval's call to
truncate_inode_pages_range would get rid of the pages in memory,
but only if the reference count drops to 0.

Unfortunately, gfs2_rgrp_brelse was setting bi->bi_bh = NULL.
So when rgrp_go_sync called gfs2_rgrp_brelse, it lost the pointer
to the buffer_heads in cases where the reference count was still 1.
Therefore, when rgrp_go_inval called gfs2_rgrp_brelse a second time,
it failed the check for "if (bi->bi_bh)" and thus failed to call
brelse a second time. Because of that, the reference count on those
buffers sometimes failed to drop from 1 to 0. And that caused
function truncate_inode_pages_range to keep the pages in page cache
rather than freeing them.

The next time the rgrp glock was acquired, the metadata read of
the rgrp buffers re-used the pages in memory, which were now
wrong because they were likely modified by the other node who
acquired the glock in EX (which is why we demoted the glock).
This re-use of the page cache caused corruption because changes
made by the other nodes were never seen, so the bitmaps were
inaccurate.

For some reason, the problem became most apparent when journal
replay forced the replay of rgrps in memory, which caused newer
rgrp data to be overwritten by the older in-core pages.

A big part of the problem was that the rgrp buffer were released
in multiple places: The go_unlock function would release them when
the glock was released rather than when the glock is demoted,
which is clearly wrong because our intent was to cache them until
the glock is demoted from SH or EX.

This patch attempts to clean up the mess and make one consistent
and centralized mechanism for managing the rgrp buffer_heads by
implementing several changes:

1. It eliminates the call to gfs2_rgrp_brelse() from rgrp_go_sync.
We don't want to release the buffers or zero the pointers when
syncing for the reasons stated above. It only makes sense to
release them when the glock is actually invalidated (go_inval).
And when we do, then we set the bh pointers to NULL.
2. The go_unlock function (which was only used for rgrps) is
eliminated, as we've talked about doing many times before.
The go_unlock function was called too early in the glock dq
process, and should not happen until the glock is invalidated.
3. It also eliminates the call to rgrp_brelse in gfs2_clear_rgrpd.
That will now happen automatically when the rgrp glocks are
demoted, and shouldn't happen any sooner or later than that.
Instead, function gfs2_clear_rgrpd has been modified to demote
the rgrp glocks, and therefore, free those pages, before the
remaining glocks are culled by gfs2_gl_hash_clear. This
prevents the gl_object from hanging around when the glocks are
culled.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Report errors before withdraw

In gfs2_rgrp_verify and compute_bitstructs, make sure to report errors before
withdrawing the filesystem: otherwise, when we withdraw first and withdraw is
configured to panic, we'll never get to the error reporting.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: remove unused LBIT macros

Since commit 223b2b889f37 ("GFS2: Fix alignment issue and tidy
gfs2_bitfit"), these 3 macros aren't used anymore, so remove them.

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Fix possible fs name overflows

This patch fixes three places in which temporary character buffers
could overflow due to the addition of the file system id from patch
3792ce973f07. Thanks to Dan Carpenter for pointing it out.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: replace more printk with calls to fs_info and friends

This patch replaces a few leftover printk errors with calls to
fs_info and similar, so that the file system having the error is
properly logged.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: dump fsid when dumping glock problems

Before this patch, if a glock error was encountered, the glock with
the problem was dumped. But sometimes you may have lots of file systems
mounted, and that doesn't tell you which file system it was for.

This patch adds a new boolean parameter fsid to the dump_glock family
of functions. For non-error cases, such as dumping the glocks debugfs
file, the fsid is not dumped in order to keep lock dumps and glocktop
as clean as possible. For all error cases, such as GLOCK_BUG_ON, the
file system id is now printed. This will make it easier to debug.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 398

Based on 1 normalized pattern(s):

this copyrighted material is made available to anyone wishing to use
modify copy or redistribute it subject to the terms and conditions
of the gnu general public license version 2

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 44 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531081038.653000175@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

gfs2: Rename gfs2_trans_{add_unrevoke => remove_revoke}

Rename gfs2_trans_add_unrevoke to gfs2_trans_remove_revoke: there is no
such thing as an "unrevoke" object; all this function does is remove
existing revoke objects plus some bookkeeping.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Fix loop in gfs2_rbm_find (v2)

Fix the resource group wrap-around logic in gfs2_rbm_find that commit
e579ed4f44 broke. The bug can lead to unnecessary repeated scanning of the
same bitmaps; there is a risk that future changes will turn this into an
endless loop.

This is an updated version of commit 2d29f6b96d ("gfs2: Fix loop in
gfs2_rbm_find") which ended up being reverted because it introduced a
performance regression in iozone (see commit e74c98ca2d). Changes since v1:

- Simplify the wrap-around logic.

- Handle the case where each resource group only has a single bitmap block
(small filesystem).

- Update rd_extfail_pt whenever we scan the entire bitmap, even when we don't
start the scan at the very beginning of the bitmap.

Fixes: e579ed4f446e ("GFS2: Introduce rbm field bii")
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Revert "Fix loop in gfs2_rbm_find"

This reverts commit 2d29f6b96d8f80322ed2dd895bca590491c38d34.

It turns out that the fix can lead to a ~20 percent performance regression
in initial writes to the page cache according to iozone. Let's revert this
for now to have more time for a proper fix.

Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

gfs2: Dump nrpages for inodes and their glocks

This patch is based on an idea from Steve Whitehouse. The idea is
to dump the number of pages for inodes in the glock dumps.
The additional locking required me to drop const from quite a few
places.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Fix loop in gfs2_rbm_find

Fix the resource group wrap-around logic in gfs2_rbm_find that commit
e579ed4f44 broke. The bug can lead to unnecessary repeated scanning of the
same bitmaps; there is a risk that future changes will turn this into an
endless loop.

Fixes: e579ed4f44 ("GFS2: Introduce rbm field bii")
Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: Put bitmap buffers in put_super

gfs2_put_super calls gfs2_clear_rgrpd to destroy the gfs2_rgrpd objects
attached to the resource group glocks. That function should release the
buffers attached to the gfs2_bitmap objects (bi_bh), but the call to
gfs2_rgrp_brelse for doing that is missing.

When gfs2_releasepage later runs across these buffers which are still
referenced, it refuses to free them. This causes the pages the buffers
are attached to to remain referenced as well. With enough mount/unmount
cycles, the system will eventually run out of memory.

Fix this by adding the missing call to gfs2_rgrp_brelse in
gfs2_clear_rgrpd.

(Also fix a gfs2_rgrp_relse -> gfs2_rgrp_brelse typo in a comment.)

Fixes: 39b0f1e92908 ("GFS2: Don't brelse rgrp buffer_heads every allocation")
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Pass resource group to rgblk_free

Function rgblk_free can only deal with one resource group at a time, so
pass that resource group is as a parameter. Several of the callers
already have the resource group at hand, so we only need additional
lookup code in a few places.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Steven Whitehouse <swhiteho@redhat.com>

gfs2: Remove unnecessary gfs2_rlist_alloc parameter

The state parameter of gfs2_rlist_alloc is set to LM_ST_EXCLUSIVE in all
calls, so remove it and hardcode that state in gfs2_rlist_alloc instead.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Steven Whitehouse <swhiteho@redhat.com>

gfs2: Fix marking bitmaps non-full

Reservations in gfs can span multiple gfs2_bitmaps (but they won't span
multiple resource groups). When removing a reservation, we want to
clear the GBF_FULL flags of all involved gfs2_bitmaps, not just that of
the first bitmap.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Steven Whitehouse <swhiteho@redhat.com>

gfs2: Fix some minor typos

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Steven Whitehouse <swhiteho@redhat.com>

gfs2: Rename bitmap.bi_{len => bytes}

This field indicates the size of the bitmap in bytes, similar to how the
bi_blocks field indicates the size of the bitmap in blocks.

In count_unlinked, replace an instance of bi_bytes * GFS2_NBBY by
bi_blocks.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Steven Whitehouse <swhiteho@redhat.com>

gfs2: Remove unused RGRP_RSRV_MINBYTES definition

This definition is only used to define RGRP_RSRV_MINBLKS, with no
benefit over defining RGRP_RSRV_MINBLKS directly.

In addition, instead of forcing RGRP_RSRV_MINBLKS to be of type u32,
cast it to that type where that type is required.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Steven Whitehouse <swhiteho@redhat.com>

gfs2: Move rs_{sizehint, rgd_gh} fields into the inode

Move the rs_sizehint and rs_rgd_gh fields from struct gfs2_blkreserv
into the inode: they are more closely related to the inode than to a
particular reservation.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Steven Whitehouse <swhiteho@redhat.com>

gfs2: Clean up out-of-bounds check in gfs2_rbm_from_block

We already have a function that checks if a block is within a resource
group, so use that in gfs2_rbm_from_block as well.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Steven Whitehouse <swhiteho@redhat.com>

gfs2: Always check the result of gfs2_rbm_from_block

When gfs2_rbm_from_block fails, the rbm it returns is undefined, so we
always want to make sure gfs2_rbm_from_block has succeeded before
looking at the rbm.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Steven Whitehouse <swhiteho@redhat.com>

gfs2: Use fs_* functions instead of pr_* function where we can

Before this patch, various errors and messages were reported using
the pr_* functions: pr_err, pr_warn, pr_info, etc., but that does
not tell you which gfs2 mount had the problem, which is often vital
to debugging. This patch changes the calls from pr_* to fs_* in
most of the messages so that the file system id is printed along
with the message.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: Don't set GFS2_RDF_UPTODATE when the lvb is updated

The GFS2_RDF_UPTODATE flag in the rgrp is used to determine when
a rgrp buffer is valid. It's cleared when the glock is invalidated,
signifying that the buffer data is now invalid. But before this
patch, function update_rgrp_lvb was setting the flag when it
determined it had a valid lvb. But that's an invalid assumption:
just because you have a valid lvb doesn't mean you have valid
buffers. After all, another node may have made the lvb valid,
and this node just fetched it from the glock via dlm.

Consider this scenario:
1. The file system is mounted with RGRPLVB option.
2. In gfs2_inplace_reserve it locks the rgrp glock EX, but thanks
to GL_SKIP, it skips the gfs2_rgrp_bh_get.
3. Since loops == 0 and the allocation target (ap->target) is
bigger than the largest known chunk of blocks in the rgrp
(rs->rs_rbm.rgd->rd_extfail_pt) it skips that rgrp and bypasses
the call to gfs2_rgrp_bh_get there as well.
4. update_rgrp_lvb sees the lvb MAGIC number is valid, so bypasses
gfs2_rgrp_bh_get, but it still sets sets GFS2_RDF_UPTODATE due
to this invalid assumption.
5. The next time update_rgrp_lvb is called, it sees the bit is set
and just returns 0, assuming both the lvb and rgrp are both
uptodate. But since this is a smaller allocation, or space has
been freed by another node, thus adjusting the lvb values,
it decides to use the rgrp for allocations, with invalid rd_free
due to the fact it was never updated.

This patch changes update_rgrp_lvb so it doesn't set the UPTODATE
flag anymore. That way, it has no choice but to fetch the latest
values.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: improve debug information when lvb mismatches are found

Before this patch, gfs2_rgrp_bh_get would check for lvb mismatches,
but it wouldn't tell you what was actually wrong. This patch adds
more information to help us debug it. It also makes rgrp consistency
checks dump any bad rgrps, and the rgrp dump code dump any lvbs
as well as the rgrp itself.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>

gfs2: eliminate update_rgrp_lvb_unlinked

Function update_rgrp_lvb_unlinked used to do the same thing as
be32_add_cpu. This patch removes it in favor of using be32_add_cpu
directly.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andrew Price <anprice@redhat.com>

gfs2: Fix gfs2_testbit to use clone bitmaps

Function gfs2_testbit is called in three places. Two of those places,
gfs2_alloc_extent and gfs2_unaligned_extlen, should be using the clone
bitmaps, not the "real" bitmaps. Function gfs2_unaligned_extlen is used
by the block reservations scheme to determine the length of an extent of
free blocks. Before this patch, it wasn't using the clone bitmap, which
means recently-freed blocks were treated as free blocks for the purposes
of an allocation.

This patch adds a new parameter to gfs2_testbit to indicate whether or
not the clone bitmaps should be used (if available).

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: cleanup: call gfs2_rgrp_ondisk2lvb from gfs2_rgrp_out

Before this patch gfs2_rgrp_ondisk2lvb was called after every call
to gfs2_rgrp_out. This patch just calls it directly from within
gfs2_rgrp_out, and moves the function to be before it so we don't
need a function prototype.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>

GFS2: rgrp free blocks used incorrectly

Before this patch, several functions in rgrp.c checked the value of
rgd->rd_free_clone. That does not take into account blocks that were
reserved by a multi-block reservation. This causes a problem when
space gets tight in the file system. For example, when function
gfs2_inplace_reserve checks to see if a rgrp has enough blocks to
satisfy the request, it can accept a rgrp that it should reject
because, although there are enough blocks to satisfy the request
_now_, those blocks may be reserved for another running process.

A second problem with this occurs when we've reserved the remaining
blocks in an rgrp: function rg_mblk_search() can reject an rgrp
improperly because it calculates:

u32 free_blocks = rgd->rd_free_clone - rgd->rd_reserved;

But rd_reserved includes blocks that the current process just
reserved in its own call to inplace_reserve. For example, it can
reserve the last 128 blocks of an rgrp, then reject that same rgrp
because the above calculates out to free_blocks = 0;

Consequences include, but are not limited to, (1) leaving holes,
and thus increasing file system fragmentation, and (2) reporting
file system is full long before it actually is.

This patch introduces a new function, rgd_free, which returns the
number of clone-free blocks (blocks that are truly free as opposed
to blocks that are still being used because an unlinked file is
still open) minus the number of blocks reserved by processes, but
not counting the blocks we ourselves reserved (because obviously
we need to allocate them).

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Don't reject a supposedly full bitmap if we have blocks reserved

Before this patch, you could get into situations like this:

1. Process 1 searches for X free blocks, finds them, makes a reservation
2. Process 2 searches for free blocks in the same rgrp, but now the
bitmap is full because process 1's reservation is skipped over.
So it marks the bitmap as GBF_FULL.
3. Process 1 tries to allocate blocks from its own reservation, but
since the GBF_FULL bit is set, it skips over the rgrp and searches
elsewhere, thus not using its own reservation.

This patch adds an additional check to allow processes to use their
own reservations.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Eliminate redundant ip->i_rgd

GFS2 remembers the last rgrp used for allocations in ip->i_rgd.
However, block allocations are made by way of a reservations structure,
ip->i_res, which keeps the last rgrp in ip->i_res.rs_rgd, and ip->i_res
is kept in sync with ip->i_res.rs_rgd, so it's redundant. Get rid of
ip->i_rgd and just use ip->i_res.rs_rgd in its place.

Based on patches by Robert Peterson.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: Stop messing with ip->i_rgd in the rlist code

In the resource group list code, keep the last resource group added in
the last position in the array. Check against that instead of messing
with ip->i_rgd.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: eliminate rs_inum and reduce the size of gfs2 inodes

Before this patch, block reservations kept track of the inode
number. At one point, that was a valid thing to do. However, since
we made the reservation a part of the inode (rather than a pointer
to a separate allocated object) the reservation can determine the
inode number by using container_of. This saves us a little memory
in our inode.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>

treewide: kmalloc() -> kmalloc_array()

The kmalloc() function has a 2-factor argument form, kmalloc_array(). This
patch replaces cases of:

kmalloc(a * b, gfp)

with:
kmalloc_array(a * b, gfp)

as well as handling cases of:

kmalloc(a * b * c, gfp)

with:

kmalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

kmalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

kmalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The tools/ directory was manually excluded, since it has its own
implementation of kmalloc().

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
kmalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
kmalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
kmalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
kmalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
kmalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
|
kmalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kmalloc
+ kmalloc_array
(
- SIZE * COUNT
+ COUNT, SIZE
, ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
kmalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kmalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kmalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kmalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
kmalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kmalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kmalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kmalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kmalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
kmalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
kmalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
kmalloc(C1 * C2 * C3, ...)
|
kmalloc(
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
kmalloc(
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
kmalloc(
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
kmalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
kmalloc(sizeof(THING) * C2, ...)
|
kmalloc(sizeof(TYPE) * C2, ...)
|
kmalloc(C1 * C2 * C3, ...)
|
kmalloc(C1 * C2, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- (E1) * E2
+ E1, E2
, ...)
|
- kmalloc
+ kmalloc_array
(
- (E1) * (E2)
+ E1, E2
, ...)
|
- kmalloc
+ kmalloc_array
(
- E1 * E2
+ E1, E2
, ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>

GFS2: gfs2_free_extlen can return an extent that is too long

Function gfs2_free_extlen calculates the length of an extent of
free blocks that may be reserved. The end pointer was calculated as
end = start + bh->b_size but b_size is incorrect because the
bitmap usually stops prior to the end of the buffer data on
the last bitmap.

What this means is that when you do a write, you can reserve a
chunk of blocks that runs off the end of the last bitmap. For
example, I've got a file system where there is only one bitmap
for each rgrp, so ri_length==1. I saw cases in which iozone
tried to do a big write, grabbed a large block reservation,
chose rgrp 5464152, which has ri_data0 5464153 and ri_data 8188.
So 5464153 + 8188 = 5472341 which is the end of the rgrp.

When it grabbed a reservation it got back: 5470936, length 7229.
But 5470936 + 7229 = 5478165. So the reservation starts inside
the rgrp but runs 5824 blocks past the end of the bitmap.

This patch fixes the calculation so it won't exceed the last
bitmap. It also adds a BUG_ON to guard against overflows in the
future.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: Add a few missing newlines in messages

Some of the info, warning, and error messages are missing their trailing
newline.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

GFS2: Log the reason for log flushes in every log header

This patch just adds the capability for GFS2 to track which function
called gfs2_log_flush. This should make it easier to diagnose
problems based on the sequence of events found in the journals.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>

GFS2: Introduce new gfs2_log_header_v2

This patch adds a new structure called gfs2_log_header_v2 which is used
to store expanded fields into previously unused areas of the log headers
(i.e., this change is backwards compatible). Some of these are used for
debug purposes so we can backtrack when problems occur. Others are
reserved for future expansion.

This patch is based on a prototype from Steve Whitehouse.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

gfs2: Add gfs2_blk2rgrpd comment and fix incorrect use

Document when to use gfs2_blk2rgrpd for "inexact" resource group
matching. Based on that, fix an incorrect use of gfs2_blk2rgrpd in
sweep_bh_for_rgrps.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: Add a crc field to resource group headers

Add the rg_crc field to store a crc32 of the gfs2_rgrp structure. This
allows us to check resource group headers' integrity and removes the
requirement to check them against the rindex entries in fsck. If this
field is found to be zero, it should be ignored (or updated with an
accurate value).

Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: Add rindex fields to rgrp headers

Add rg_data0, rg_data and rg_bitbytes to struct gfs2_rgrp. The fields
are identical to their counterparts in struct gfs2_rindex and are
intended to reduce the use of the rindex. For now the fields are only
written back as the in-memory equivalents in struct gfs2_rgrpd are set
using values from the rindex. However, they are needed at this point so
that userspace can make use of them, allowing a migration away from the
rindex over time.

The new fields take up previously reserved space which was explicitly
zeroed on write so, in clusters with mixed kernels, these fields could
get zeroed after being set and this should not be treated as an error.

Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: Add a next-resource-group pointer to resource groups

Add a new rg_skip field to struct gfs2_rgrp, replacing __pad. The
rg_skip field has the following meaning:

- If rg_skip is zero, it is considered unset and not useful.
- If rg_skip is non-zero, its value will be the number of blocks between
this rgrp's address and the next rgrp's address. This can be used as a
hint by fsck.gfs2 when rebuilding a bad rindex, for example.

This will provide less dependency on the rindex in future, and allow
tools such as fsck.gfs2 to iterate the resource groups without keeping
the rindex around.

The field is updated in gfs2_rgrp_out() so that existing file systems
will have it set. This means that any resource groups that aren't ever
written will not be updated. The final rgrp is a special case as there
is no next rgrp, so it will always have a rg_skip of 0 (unless the fs is
extended).

Before this patch, gfs2_rgrp_out() zeroes the __pad field explicitly, so
the rg_skip field can get set back to 0 in cases where nodes with and
without this patch are mixed in a cluster. In some cases, the field may
bounce between being set by one node and then zeroed by another which
may harm performance slightly, e.g. when two nodes create many small
files. In testing this situation is rare but it becomes more likely as
the filesystem fills up and there are fewer resource groups to choose
from. The problem goes away when all nodes are running with this patch.
Dipping into the space currently occupied by the rg_reserved field would
have resulted in the same problem as it is also explicitly zeroed, so
unfortunately there is no other way around it.

Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

GFS2: Combine gfs2_free_di with gfs2_free_uninit_di

Before this patch, function gfs2_free_di was 4 lines of code, and
one of those lines was to call gfs2_free_uninit_di. Although
unlikely, if function gfs2_free_uninit_di encountered an error
finding the block to be freed, the error was silently ignored by the
caller, which went ahead and improperly did a quota-change operation
and meta_wipe despite the error. This patch combines the two
functions into one to make the code more readable and fixes the bug
by returning from the combined function before it takes those next
incorrect steps.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

GFS2: Fix gl_object warnings

The following cleanup is needed to avoid spilling the syslog with
false warnings.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

GFS2: Don't bother trying to add rgrps to the lru list

This patch removes a call to gfs2_glock_add_to_lru from function
gfs2_clear_rgrpd. The call is just a waste of time because as soon
as it adds it to the lru_list, the call to gfs2_glock_put takes it
back off again.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: Protect gl->gl_object by spin lock

Put all remaining accesses to gl->gl_object under the
gl->gl_lockref.lock spinlock to prevent races.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

GFS2: Non-recursive delete

Implement truncate/delete as a non-recursive algorithm. The older
algorithm was implemented with recursion to strip off each layer
at a time (going by height, starting with the maximum height.
This version tries to do the same thing but without recursion,
and without needing to allocate new structures or lists in memory.

For example, say you want to truncate a very large file to 1 byte,
and its end-of-file metapath is: 0.505.463.428. The starting
metapath would be 0.0.0.0. Since it's a truncate to non-zero, it
needs to preserve that byte, and all metadata pointing to it.
So it would start at 0.0.0.0, look up all its metadata buffers,
then free all data blocks pointed to at the highest level.
After that buffer is "swept", it moves on to 0.0.0.1, then
0.0.0.2, etc., reading in buffers and sweeping them clean.
When it gets to the end of the 0.0.0 metadata buffer (for 4K
blocks the last valid one is 0.0.0.508), it backs up to the
previous height and starts working on 0.0.1.0, then 0.0.1.1,
and so forth. After it reaches the end and sweeps 0.0.1.508,
it continues with 0.0.2.0, and so on. When that height is
exhausted, and it reaches 0.0.508.508 it backs up another level,
to 0.1.0.0, then 0.1.0.1, through 0.1.0.508. So it has to keep
marching backwards and forwards through the metadata until it's
all swept clean. Once it has all the data blocks freed, it
lowers the strip height, and begins the process all over again,
but with one less height. This time it sweeps 0.0.0 through
0.505.463. When that's clean, it lowers the strip height again
and works to free 0.505. Eventually it strips the lowest height, 0.
For a delete or truncate to 0, all metadata for all heights of
0.0.0.0 would be freed. For a truncate to 1 byte, 0.0.0.0 would
be preserved.

This isn't much different from normal integer incrementing,
where an integer gets incremented from 0000 (0.0.0.0) to 3021
(3.0.2.1). So 0000 gets increments to 0001, 0002, up to 0009,
then on to 0010, 0011 up to 0099, then 0100 and so forth. It's
just that each "digit" goes from 0 to 508 (for a total of 509
pointers) rather than from 0 to 9.

Note that the dinode will only have 483 pointers due to the
dinode structure itself.

Also note: this is just an example. These numbers (509 and 483)
are based on a standard 4K block size. Smaller block sizes will
yield smaller numbers of indirect pointers accordingly.

The truncation process is accomplished with the help of two
major functions and a few helper functions.

Functions do_strip and recursive_scan are obsolete, so removed.

New function sweep_bh_for_rgrps cleans a buffer_head pointed to
by the given metapath and height. By cleaning, I mean it frees
all blocks starting at the offset passed in metapath. It starts
at the first block in the buffer pointed to by the metapath and
identifies its resource group (rgrp). From there it frees all
subsequent block pointers that lie within that rgrp. If it's
already inside a transaction, it stays within it as long as it
can. In other words, it doesn't close a transaction until it knows
it's freed what it can from the resource group. In this way,
multiple buffers may be cleaned in a single transaction, as long
as those blocks in the buffer all lie within the same rgrp.

If it's not in a transaction, it starts one. If the buffer_head
has references to blocks within multiple rgrps, it frees all the
blocks inside the first rgrp it finds, then closes the
transaction. Then it repeats the cycle: identifies the next
unfreed block, uses it to find its rgrp, then starts a new
transaction for that set. It repeats this process repeatedly
until the buffer_head contains no more references to any blocks
past the given metapath.

Function trunc_dealloc has been reworked into a finite state
automaton. It has basically 3 active states:
DEALLOC_MP_FULL, DEALLOC_MP_LOWER, and DEALLOC_FILL_MP:

The DEALLOC_MP_FULL state implies the metapath has a full set
of buffers out to the "shrink height", and therefore, it can
call function sweep_bh_for_rgrps to free the blocks within the
highest height of the metapath. If it's just swept the lowest
level (or an error has occurred) the state machine is ended.
Otherwise it proceeds to the DEALLOC_MP_LOWER state.

The DEALLOC_MP_LOWER state implies we are finished with a given
buffer_head, which may now be released, and therefore we are
then missing some buffer information from the metapath. So we
need to find more buffers to read in. In most cases, this is
just a matter of releasing the buffer_head and moving to the
next pointer from the previous height, so it may be read in and
swept as well. If it can't find another non-null pointer to
process, it checks whether it's reached the end of a height
and needs to lower the strip height, or whether it still needs
move forward through the previous height's metadata. In this
state, all zero-pointers are skipped. From this state, it can
only loop around (once more backing up another height) or,
once a valid metapath is found (one that has non-zero
pointers), proceed to state DEALLOC_FILL_MP.

The DEALLOC_FILL_MP state implies that we have a metapath
but not all its buffers are read in. So we must proceed to read
in buffer_heads until the metapath has a valid buffer for every
height. If the previous state backed us up 3 heights, we may
need to read in a buffer, increment the height, then repeat the
process until buffers have been read in for all required heights.
If it's successful reading a buffer, and it's at the highest
height we need, it proceeds back to the DEALLOC_MP_FULL state.
If it's unable to fill in a buffer, (encounters a hole, etc.)
it tries to find another non-zero block pointer. If they're all
zero, it lowers the height and returns to the DEALLOC_MP_LOWER
state. If it finds a good non-null pointer, it loops around and
reads it in, while keeping the metapath in lock-step with the
pointers it examines.

The state machine runs until the truncation request is
satisfied. Then any transactions are ended, the quota and
statfs data are updated, and the function is complete.

Helper function metaptr1 was introduced to be an easy way to
determine the start of a buffer_head's indirect pointers.

Helper function lookup_mp_height was introduced to find a
metapath index and read in the buffer that corresponds to it.
In this way, function lookup_metapath becomes a simple loop to
call it for every height.

Helper function fillup_metapath is similar to lookup_metapath
except it can do partial lookups. If the state machine
backed up multiple levels (like 2999 wrapping to 3000) it
needs to find out the next starting point and start issuing
metadata reads at that point.

Helper function hptrs is a shortcut to determine how many
pointers should be expected in a buffer. Height 0 is the dinode
which has fewer pointers than the others.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

GFS2: Check rs_free with rd_rsspin protection

For the last process to close a file opened for write, function
gfs2_rsqa_delete was deleting the file's inode's block reservation
out of the rgrp reservations tree. Then it was checking to make sure
rs_free was 0, but it was performing the check outside the protection
of rd_rsspin spin_lock. The rd_rsspin spin_lock protection is needed
to prevent a race between the process freeing the reservation and
another who is allocating a new set of blocks inside the same rgrp
for the same inode, thus changing its value.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: Lock holder cleanup

Make the code more readable by cleaning up the different ways of
initializing lock holders and checking for initialized lock holders:
mark lock holders as uninitialized by setting the holder's glock to NULL
(gfs2_holder_mark_uninitialized) instead of zeroing out the entire
object or using a separate flag. Recognize initialized holders by their
non-NULL glock (gfs2_holder_initialized). Don't zero out holder objects
which are immeditiately initialized via gfs2_holder_init or
gfs2_glock_nq_init.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

GFS2: don't set rgrp gl_object until it's inserted into rgrp tree

Before this patch, function read_rindex_entry would set a rgrp
glock's gl_object pointer to itself before inserting the rgrp into
the rgrp rbtree. The problem is: if another process was also reading
the rgrp in, and had already inserted its newly created rgrp, then
the second call to read_rindex_entry would overwrite that value,
then return a bad return code to the caller. Later, other functions
would reference the now-freed rgrp memory by way of gl_object.
In some cases, that could result in gfs2_rgrp_brelse being called
twice for the same rgrp: once for the failed attempt and once for
the "real" rgrp release. Eventually the kernel would panic.
There are also a number of other things that could go wrong when
a kernel module is accessing freed storage. For example, this could
result in rgrp corruption because the fake rgrp would point to a
fake bitmap in memory too, causing gfs2_inplace_reserve to search
some random memory for free blocks, and find some, since we were
never setting rgd->rd_bits to NULL before freeing it.

This patch fixes the problem by not setting gl_object until we
have successfully inserted the rgrp into the rbtree. Also, it sets
rd_bits to NULL as it frees them, which will ensure any accidental
access to the wrong rgrp will result in a kernel panic rather than
file system corruption, which is preferred.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

GFS2: Remove allocation parms from gfs2_rbm_find

Struct gfs2_alloc_parms ap is never referenced in function
gfs2_rbm_find, so this patch removes it.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros

PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized. And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special. They are
not.

The changes are pretty straight-forward:

- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

- page_cache_get() -> get_page();

- page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

GFS2: Always use iopen glock for gl_deletes

Before this patch, when function try_rgrp_unlink queued a glock for
delete_work to reclaim the space, it used the inode glock to do so.
That's different from the iopen callback which uses the iopen glock
for the same purpose. We should be consistent and always use the
iopen glock. This may also save us reference counting problems with
the inode glock, since clear_glock does an extra glock_put() for the
inode glock.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

GFS2: Make rgrp reservations part of the gfs2_inode structure

Before this patch, multi-block reservation structures were allocated
from a special slab. This patch folds the structure into the gfs2_inode
structure. The disadvantage is that the gfs2_inode needs more memory,
even when a file is opened read-only. The advantages are: (a) we don't
need the special slab and the extra time it takes to allocate and
deallocate from it. (b) we no longer need to worry that the structure
exists for things like quota management. (c) This also allows us to
remove the calls to get_write_access and put_write_access since we
know the structure will exist.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

GFS2: Extract quota data from reservations structure (revert 5407e24)

This patch basically reverts the majority of patch 5407e24.
That patch eliminated the gfs2_qadata structure in favor of just
using the reservations structure. The problem with doing that is that
it increases the size of the reservations structure. That is not an
issue until it comes time to fold the reservations structure into the
inode in memory so we know it's always there. By separating out the
quota structure again, we aren't punishing the non-quota users by
making all the inodes bigger, requiring more slab space. This patch
creates a new slab area to allocate the quota stuff so it's managed
a little more sanely.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: Extended attribute readahead

When gfs2 allocates an inode and its extended attribute block next to
each other at inode create time, the inode's directory entry indicates
that in de_rahead. In that case, we can readahead the extended
attribute block when we read in the inode.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

GFS2: Fix rgrp end rounding problem for bsize < page size

This patch fixes a bug introduced by commit 7005c3e. That patch
tries to map a vm range for resource groups, but the calculation
breaks down when the block size is less than the page size.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: Remove gl_spin define

Commit e66cf161 replaced the gl_spin spinlock in struct gfs2_glock with a
gl_lockref lockref and defined gl_spin as gl_lockref.lock (the spinlock in
gl_lockref). Remove that define to make the references to gl_lockref.lock more
obvious.

Signed-off-by: Andreas Gruenbacher <andreas.gruenbacher@gmail.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: Make statistics unsigned, suitable for use with do_div()

None of these statistics can meaningfully be negative, and the
numerator for do_div() must have the type u64. The generic
implementation of do_div() used on some 32-bit architectures asserts
that, resulting in a compiler error in gfs2_rgrp_congested().

Fixes: 0166b197c2ed ("GFS2: Average in only non-zero round-trip times ...")

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Andreas Gruenbacher <agruenba@redhat.com>

GFS2: Move glock superblock pointer to field gl_name

What uniquely identifies a glock in the glock hash table is not
gl_name, but gl_name and its superblock pointer. This patch makes
the gl_name field correspond to a unique glock identifier. That will
allow us to simplify hashing with a future patch, since the hash
algorithm can then take the gl_name and hash its components in one
operation.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Don't brelse rgrp buffer_heads every allocation

This patch allows the block allocation code to retain the buffers
for the resource groups so they don't need to be re-read from buffer
cache with every request. This is a performance improvement that's
especially noticeable when resource groups are very large. For
example, with 2GB resource groups and 4K blocks, there can be 33
blocks for every resource group. This patch allows those 33 buffers
to be kept around and not read in and thrown away with every
operation. The buffers are released when the resource group is
either synced or invalidated.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Steven Whitehouse <swhiteho@redhat.com>
Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>

gfs2: fix shadow warning in gfs2_rbm_find()

bi was already declared and initialized globally in gfs2_rbm_find()

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

gfs2: handle NULL rgd in set_rgrp_preferences

The function set_rgrp_preferences() does not handle the (rarely
returned) NULL value from gfs2_rgrpd_get_next() and this patch
fixes that.

The fs image in question is only 150MB in size which allows for
only 1 rgrp to be created. The in-memory rb tree has only 1 node
and when gfs2_rgrpd_get_next() is called on this sole rgrp, it
returns NULL. (Default behavior is to wrap around the rb tree and
return the first node to give the illusion of a circular linked
list. In the case of only 1 rgrp, we can't have
gfs2_rgrpd_get_next() return the same rgrp (first, last, next all
point to the same rgrp)... that would cause unintended consequences
and infinite loops.)

Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

GFS2: Average in only non-zero round-trip times for congestion stats

This patch changes function gfs2_rgrp_congested so that it only factors
in non-zero values into its average round trip time. If the round-trip
time is zero for a particular cpu, that cpu has obviously never dealt
with bouncing the resource group in question, so factoring in a zero
value will only skew the numbers. It also fixes a compile error on
some arches related to division.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Use average srttb value in congestion calculations

This patch changes function gfs2_rgrp_congested so that it uses an
average srttb (smoothed round trip time for blocking rgrp glocks)
rather than the CPU-specific value. If we use the CPU-specific value
it can incorrectly report no contention when there really is contention
due to the glock processing occurring on a different CPU.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>

gfs2: allow quota_check and inplace_reserve to return available blocks

struct gfs2_alloc_parms is passed to gfs2_quota_check() and
gfs2_inplace_reserve() with ap->target containing the number of
blocks being requested for allocation in the current operation.

We add a new field to struct gfs2_alloc_parms called 'allowed'.
gfs2_quota_check() and gfs2_inplace_reserve() return the max
blocks allowed by quota and the max blocks allowed by the chosen
rgrp respectively in 'allowed'.

A new field 'min_target', when non-zero, tells gfs2_quota_check()
and gfs2_inplace_reserve() to not return -EDQUOT/-ENOSPC when
there are atleast 'min_target' blocks allowable/available. The
assumption is that the caller is ok with just 'min_target' blocks
and will likely proceed with allocating them.

Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: If we use up our block reservation, request more next time

If we run out of blocks for a given multi-block allocation, we obviously
did not reserve enough. We should reserve more blocks for the next
reservation to reduce fragmentation. This patch increases the size hint
for reservations when they run out.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Set of distributed preferences for rgrps

This patch tries to use the journal numbers to evenly distribute
which node prefers which resource group for block allocations. This
is to help performance.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Use gfs2_rbm_incr in rgblk_free

This patch speeds up GFS2 unlink operations by using function
gfs2_rbm_incr rather than continuously calculating the rbm.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: fix bad inode i_goal values during block allocation

This patch checks if i_goal is either zero or if doesn't exist
within any rgrp (i.e gfs2_blk2rgrpd() returns NULL). If so, it
assigns the ip->i_no_addr block as the i_goal.

There are two scenarios where a bad i_goal can result in a
-EBADSLT error.

1. Attempting to allocate to an existing inode:
Control reaches gfs2_inplace_reserve() and ip->i_goal is bad.
We need to fix i_goal here.

2. A new inode is created in a directory whose i_goal is hosed:
In this case, the parent dir's i_goal is copied onto the new
inode. Since the new inode is not yet created, the ip->i_no_addr
field is invalid and so, the fix in gfs2_inplace_reserve() as per
1) won't work in this scenario. We need to catch and fix it sooner
in the parent dir itself (gfs2_create_inode()), before it is
copied to the new inode.

Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: fs/gfs2/rgrp.c: kernel-doc warning fixes

Cc: cluster-devel@redhat.com
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: remove transaction glock

GFS2 has a transaction glock, which must be grabbed for every
transaction, whose purpose is to deal with freezing the filesystem.
Aside from this involving a large amount of locking, it is very easy to
make the current fsfreeze code hang on unfreezing.

This patch rewrites how gfs2 handles freezing the filesystem. The
transaction glock is removed. In it's place is a freeze glock, which is
cached (but not held) in a shared state by every node in the cluster
when the filesystem is mounted. This lock only needs to be grabbed on
freezing, and actions which need to be safe from freezing, like
recovery.

When a node wants to freeze the filesystem, it grabs this glock
exclusively. When the freeze glock state changes on the nodes (either
from shared to unlocked, or shared to exclusive), the filesystem does a
special log flush. gfs2_log_flush() does all the work for flushing out
the and shutting down the incore log, and then it tries to grab the
freeze glock in a shared state again. Since the filesystem is stuck in
gfs2_log_flush, no new transaction can start, and nothing can be written
to disk. Unfreezing the filesytem simply involes dropping the freeze
glock, allowing gfs2_log_flush() to grab and then release the shared
lock, so it is cached for next time.

However, in order for the unfreezing ioctl to occur, gfs2 needs to get a
shared lock on the filesystem root directory inode to check permissions.
If that glock has already been grabbed exclusively, fsfreeze will be
unable to get the shared lock and unfreeze the filesystem.

In order to allow the unfreeze, this patch makes gfs2 grab a shared lock
on the filesystem root directory during the freeze, and hold it until it
unfreezes the filesystem. The functions which need to grab a shared
lock in order to allow the unfreeze ioctl to be issued now use the lock
grabbed by the freeze code instead.

The freeze and unfreeze code take care to make sure that this shared
lock will not be dropped while another process is using it.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Use pr_<level> more consistently

Add pr_fmt, remove embedded "GFS2: " prefixes.
This now consistently emits lower case "gfs2: " for each message.

Other miscellanea around these changes:

o Add missing newlines
o Coalesce formats
o Realign arguments

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: global conversion to pr_foo()

-All printk(KERN_foo converted to pr_foo().
-Messages updated to fit in 80 columns.
-fs_macros converted as well.
-fs_printk removed.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Mark functions as static in gfs2/rgrp.c

Mark functions as static in gfs2/rgrp.c because they are not used
outside this file.

This eliminates the following warning in gfs2/rgrp.c:
fs/gfs2/rgrp.c:1092:5: warning: no previous prototype for ‘gfs2_rgrp_bh_get’ [-Wmissing-prototypes]
fs/gfs2/rgrp.c:1157:5: warning: no previous prototype for ‘update_rgrp_lvb’ [-Wmissing-prototypes]

Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Allocate block for xattr at inode alloc time, if required

This is another step towards improving the allocation of xattr
blocks at inode allocation time. Here we take advantage of
Christoph's recent work on ACLs to allocate a block for the
xattrs early if we know that we will be adding ACLs to the
inode later on. The advantage of that is that it is much
more likely that we'll get a contiguous run of two blocks
where the first is the inode and the second is the xattr block.

We still have to fall back to the original system in case we
don't get the requested two contiguous blocks, or in case the
ACLs are too large to fit into the block.

Future patches will move more of the ACL setting code further
up the gfs2_inode_create() function. Also, I'd like to be
able to do the same thing with the xattrs from LSMs in
due course, too. That way we should be able to slowly reduce
the number of independent transactions, at least in the
most common cases.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Small cleanup

This is a small cleanup to function gfs2_rgrp_go_lock so that it
uses rgd instead of its more complicated twin.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Don't use ENOBUFS when ENOMEM is the correct error code

Al Viro has tactfully pointed out that we are using the incorrect
error code in some cases. This patch fixes that, and also removes
the (unused) return value for glock dumping.

> * gfs2_iget() - ENOBUFS instead of ENOMEM. ENOBUFS is
> "No buffer space available (POSIX.1 (XSI STREAMS option))" and since
> we don't support STREAMS it's probably fair game, but... what the hell?

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>

GFS2: Use range based functions for rgrp sync/invalidation

Each rgrp header is represented as a single extent on disk, so we
can calculate the position within the address space, since we are
using address spaces mapped 1:1 to the disk. This means that it
is possible to use the range based versions of filemap_fdatawrite/wait
and for invalidating the page cache.

Our eventual intent is to then be able to merge the address spaces
used for rgrps into a single address space, rather than to have
one for each glock, saving memory and reducing complexity.

Since during umount, the rgrp structures are disposed of before
the glocks, we need to store the extent information in the glock
so that is is available for a final invalidation. This patch uses
a field which is otherwise unused in rgrp glocks to do that, so
that we do not have to expand the size of a glock.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Remove test which is always true

Since gfs2_inplace_reserve() is always called with a valid
alloc parms structure, there is no need to test for this
within the function itself - and in any case, after we've
all ready dereferenced it anyway.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Implement a "rgrp has no extents longer than X" scheme

With the preceding patch, we started accepting block reservations
smaller than the ideal size, which requires a lot more parsing of the
bitmaps. To reduce the amount of bitmap searching, this patch
implements a scheme whereby each rgrp keeps track of the point
at this multi-block reservations will fail.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Drop inadequate rgrps from the reservation tree

This is just basically a resend of a patch I posted earlier.
It didn't change from its original, except in diff offsets, etc:

This patch fixes a bug in the GFS2 block allocation code. The problem
starts if a process already has a multi-block reservation, but for
some reason, another process disqualifies it from further allocations.
For example, the other process might set on the GFS2_RDF_ERROR bit.
The process holding the reservation jumps to label skip_rgrp, but
that label comes after the code that removes the reservation from the
tree. Therefore, the no longer usable reservation is not removed from
the rgrp's reservations tree; it's lost. Eventually, the lost reservation
causes the count of reserved blocks to get off, and eventually that
causes a BUG_ON(rs->rs_rbm.rgd->rd_reserved < rs->rs_free) to trigger.
This patch moves the call to after label skip_rgrp so that the
disqualified reservation is properly removed from the tree, thus keeping
the rgrp rd_reserved count sane.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: If requested is too large, use the largest extent in the rgrp

Here is a second try at a patch I posted earlier, which also implements
suggestions Steve made:

Before this patch, GFS2 would keep searching through all the rgrps
until it found one that had a chunk of free blocks big enough to
satisfy the size hint, which is based on the file write size,
regardless of whether the chunk was big enough to perform the write.
However, when doing big writes there may not be a large enough
chunk of free blocks in any rgrp, due to file system fragmentation.
The largest chunk may be big enough to satisfy the write request,
but it may not meet the ideal reservation size from the "size hint".
The writes would slow to a crawl because every write would search
every rgrp, then finally give up and default to a single-block write.
In my case, performance would drop from 425MB/s to 18KB/s, or 24000
times slower.

This patch basically makes it so that if we can't find a contiguous
chunk of blocks big enough to satisfy the sizehint, we'll use the
largest chunk of blocks we found that will still contain the write.
It does so by keeping track of the largest run of blocks within the
rgrp.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

gfs2: endianness misannotations

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

GFS2: Speed up starting point selection for block allocation

When setting the starting point for block allocation, there were calls
to both gfs2_rbm_to_block() and gfs2_rbm_from_block() in the common case
of there being an active reservation. The gfs2_rbm_from_block() function
can be quite slow, and since the two conversions were effectively a
no-op, it makes sense to avoid them entirely in this case.

There is no functional change here, but the code should be a bit more
efficient after this patch.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Add allocation parameters structure

This patch adds a structure to contain allocation parameters with
the intention of future expansion of this structure. The idea is
that we should be able to add more information about the allocation
in the future in order to allow the allocator to make a better job
of placing the requests on-disk.

There is no functional difference from applying this patch.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Clean up reservation removal

The reservation for an inode should be cleared when it is truncated so
that we can start again at a different offset for future allocations.
We could try and do better than that, by resetting the search based on
where the truncation started from, but this is only a first step.

In addition, there are three callers of gfs2_rs_delete() but only one
of those should really be testing the value of i_writecount. While
we get away with that in the other cases currently, I think it would
be better if we made that test specific to the one case which
requires it.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: new function gfs2_rbm_incr

Since the previous patch eliminated bi in favor of bii, this follow-on
patch needed to be adjusted accordingly. Here is the revised version.

This patch adds a new function, gfs2_rbm_incr, which increments
an rbm structure. This is more efficient than calling gfs2_rbm_to_block,
incrementing, then calling gfs2_rbm_from_block.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Introduce rbm field bii

This is a respin of the original patch. As Steve pointed out, the
introduction of field bii makes it easy to eliminate bi itself.
This revised patch does just that, replacing bi with bii.

This patch adds a new field to the rbm structure, called bii,
which is an index into the array of bitmaps for an rgrp.
This replaces *bi which was a pointer to the bitmap.
This is being done for further optimizations.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Do not reset flags on active reservations

When we used try locks for rgrps on block allocations, it was important
to clear the flags field so that we used a blocking hold on the glock.
Now that we're not doing try locks, clearing flags is unnecessary, and
a waste of time. In fact, it's probably doing the wrong thing because
it clears the GL_SKIP bit that was set for the lvb tracking purposes.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: introduce bi_blocks for optimization

This patch introduces a new field in the bitmap structure called
bi_blocks. Its purpose is to save us from constantly multiplying
bi_len by the constant GFS2_NBBY. It also paves the way for more
optimization in a future patch.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: optimize rbm_from_block wrt bi_start

In function gfs2_rbm_from_block, it starts by checking if the block
falls within the first bitmap. It does so by checking if the rbm's
offset is less than (rbm->bi->bi_start + rbm->bi->bi_len) * GFS2_NBBY.
However, the first bitmap will always have bi_start==0. Therefore
this is an unnecessary calculation in a function that gets called
billions of times. This patch removes the reference to bi_start.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fix fstrim boundary conditions

This patch correctly distinguishes two boundary conditions:

1. When the given range is entire within the unaccounted space between
two rgrps, and
2. The range begins beyond the end of the filesystem

Also fix the unit of the returned value r.len (total trimming) to be in bytes
instead of the (incorrect) 512 byte blocks

With this patch, GFS2 passes multiple iterations of all the relevant xfstests
(251, 260, 288) with different fs block sizes.

Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Increase i_writecount during gfs2_setattr_size

This patch calls get_write_access in a few functions. This
merely increases inode->i_writecount for the duration of the function.
That will ensure that any file closes won't delete the inode's
multi-block reservation while the function is running.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Use single-block reservations for directories

This patch changes the multi-block allocation code, such that
directory inodes only get a single block reserved in the bitmap.
That way, the bitmaps are more tightly packed together, and there
are fewer spans of free blocks for in-use block reservations.
This means it takes less time to find a free span of blocks in the
bitmap, which speeds things up. This increases the performance of
some workloads by almost 2X. In Nate's mockup.py script (which does
(1) create dir, (2) create dir in dir, (3) create file in that dir)
the test executes in 23 steps rather than 43 steps, a 47%
performance improvement.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Remove vestigial parameter ip from function rs_deltree

The functions that delete block reservations from the rgrp block
reservations rbtree no longer use the ip parameter. This patch
eliminates the parameter.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Clean up inode creation path

This patch cleans up the inode creation code path in GFS2. After the
Orlov allocator was merged, a number of potential improvements are
now possible, and this is a first set of these.

The quota handling is now updated so that it matches the point in
the code where the allocation takes place. This means that the one
exception in gfs2_alloc_blocks relating to quota is now no longer
required, and we can use the generic code everywhere.

In addition the call to figure out whether we need to allocate any
extra blocks in order to add a directory entry is moved higher up
gfs2_create_inode. This means that if it returns an error, we
can deal with that at a stage where it is easier to handle that case.
The returned status cannot change during the function since we hold
an exclusive lock on the directory.

Two calls to gfs2_rindex_update have been changed to one, again at
the top of gfs2_create_inode to simplify error handling.

The time stamps are also now initialised earlier in the creation
process, this is gradually moving towards being able to remove the
call to gfs2_refresh_inode in gfs2_inode_create once we have all the
fields covered.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Issue discards in 512b sectors

This patch changes GFS2's discard issuing code so that it calls
function sb_issue_discard rather than blkdev_issue_discard. The
code was calling blkdev_issue_discard and specifying the correct
sector offset and sector size, but blkdev_issue_discard expects
these values to be in terms of 512 byte sectors, even if the native
sector size for the device is different. Calling sb_issue_discard
with the BLOCK size instead ensures the correct block-to-512b-sector
translation. I verified that "minlen" is specified in blocks, so
comparing it to a number of blocks is correct.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: return error if malloc failed in gfs2_rs_alloc()

The error code in gfs2_rs_alloc() is set to ENOMEM when error
but never be used, instead, gfs2_rs_alloc() always return 0.
Fix to return 'error'.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

new helper: file_inode(file)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

GFS2: Split gfs2_trans_add_bh() into two

There is little common content in gfs2_trans_add_bh() between the data
and meta classes by the time that the functions which it calls are
taken into account. The intent here is to split this into two
separate functions. Stage one is to introduce gfs2_trans_add_data()
and gfs2_trans_add_meta() and update the callers accordingly.

Later patches will then pull in the content of gfs2_trans_add_bh()
and its dependent functions in order to clean up the code in this
area.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Reset rd_last_alloc when it reaches the end of the rgrp

In function rg_mblk_search, it's searching for multiple blocks in
a given state (e.g. "free"). If there's an active block reservation
its goal is the next free block of that. If the resource group
contains the dinode's goal block, that's used for the search. But
if neither is the case, it uses the rgrp's last allocated block.
That way, consecutive allocations appear after one another on media.
The problem comes in when you hit the end of the rgrp; it would never
start over and search from the beginning. This became a problem,
since if you deleted all the files and data from the rgrp, it would
never start over and find free blocks. So it had to keep searching
further out on the media to allocate blocks. This patch resets the
rd_last_alloc after it does an unsuccessful search at the end of
the rgrp.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Stop looking for free blocks at end of rgrp

This patch adds a return code check after calling function
gfs2_rbm_from_block while determining the free extent size.
That way, when the end of an rgrp is reached, it won't try
to process unaligned blocks after the end.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fix race in gfs2_rs_alloc

QE aio tests uncovered a race condition in gfs2_rs_alloc where it's possible
to come out of the function with a valid ip->i_res allocation but it gets
freed before use resulting in a NULL ptr dereference.

This patch envelopes the initial short-circuit check for non-NULL ip->i_res
into the mutex lock. With this patch, I was able to successfully run the
reproducer test multiple times.

Resolves: rhbz#878476
Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: remove redundant lvb pointer

The lksb struct already contains a pointer to the lvb,
so another directly from the glock struct is not needed.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fix one RG corner case

For filesystems with only a single resource group, we need to be careful
that the allocation loop will not land up with a NULL resource group. This
fixes a bug in a previous patch where the gfs2_rgrpd_get_next() function
was being used instead of gfs2_rgrpd_get_first()

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Add Orlov allocator

Just like ext3, this works on the root directory and any directory
with the +T flag set. Also, just like ext3, any subdirectory created
in one of the just mentioned cases will be allocated to a random
resource group (GFS2 equivalent of a block group).

If you are creating a set of directories, each of which will contain a
job running on a different node, then by setting +T on the parent
directory before creating the subdirectories, each will land up in a
different resource group, and thus resource group contention between
nodes will be kept to a minimum.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Add test for resource group congestion status

This patch uses information gathered by the recent glock statistics
patch in order to derrive a boolean verdict on the congestion
status of a resource group. This is then used when making decisions
on which resource group to choose during block allocation.

The aim is to avoid resource groups which are heavily contended
by other nodes, while still ensuring locality of access wherever
possible.

Once a reservation has been made in a particular resource group
we continue to use that resource group until a new reservation is
required. This should help to ensure that we do not change resource
groups too often.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Speed up gfs2_rbm_from_block

This patch is a rewrite of function gfs2_rbm_from_block. Rather than
looping to find the right bitmap, the code now does a few simple
math calculations.

I compared the performance of both algorithms side by side and the new
algorithm is noticeably faster. Sample instrumentation output from a
"fast" machine:

5 million calls: millisec spent: Orig: 166 New: 113
5 million calls: millisec spent: Orig: 189 New: 114

In addition, I ran postmark (on a somewhat slowr CPU) before the after
the new algorithm was put in place and postmark showed a decent
improvement:

Before the new algorithm:
-------------------------
Time:
645 seconds total
584 seconds of transactions (171 per second)

Files:
150087 created (232 per second)
Creation alone: 100000 files (2083 per second)
Mixed with transactions: 50087 files (85 per second)
49995 read (85 per second)
49991 appended (85 per second)
150087 deleted (232 per second)
Deletion alone: 100174 files (7705 per second)
Mixed with transactions: 49913 files (85 per second)

Data:
273.42 megabytes read (434.08 kilobytes per second)
852.13 megabytes written (1.32 megabytes per second)

With the new algorithm:
-----------------------
Time:
599 seconds total
530 seconds of transactions (188 per second)

Files:
150087 created (250 per second)
Creation alone: 100000 files (1886 per second)
Mixed with transactions: 50087 files (94 per second)
49995 read (94 per second)
49991 appended (94 per second)
150087 deleted (250 per second)
Deletion alone: 100174 files (6260 per second)
Mixed with transactions: 49913 files (94 per second)

Data:
273.42 megabytes read (467.42 kilobytes per second)
852.13 megabytes written (1.42 megabytes per second)

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fix FITRIM argument handling

Currently implementation in gfs2 uses FITRIM arguments as it were in
file system blocks units which is wrong. The FITRIM arguments
(fstrim_range.start, fstrim_range.len and fstrim_range.minlen) are
actually in bytes.

Moreover, check for start argument beyond the end of file system, len
argument being smaller than file system block and minlen argument being
bigger than biggest resource group were missing.

This commit converts the code to convert FITRIM argument to file system
blocks and also adds appropriate checks mentioned above.

All the problems were recognised by xfstests 251 and 260.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Require user to provide argument for FITRIM

When the fstrim_range argument is not provided by user in FITRIM ioctl
we should just return EFAULT and not promoting bad behaviour by filling
the structure in kernel. Let the user deal with it.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fix possible null pointer deref in gfs2_rs_alloc

Despite the return value from kmem_cache_zalloc() being checked, the
error wasn't being returned until after a possible null pointer
dereference. This patch returns the error immediately, allowing the
removal of the error variable.

Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fix infinite loop in rbm_find

This patch fixes an infinite loop in gfs2_rbm_find that was introduced
by the previous patch. The problem occurred when the length was less
than 3 but the rbm block was byte-aligned, causing it to improperly
return a extent length of zero, which caused it to spin.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Tested-by: Bob Peterson <rpeterso@redhat.com>
Tested-by: Barry Marson <bmarson@redhat.com>

GFS2: Consolidate free block searching functions

With the recently added block reservation code, an additional function
was added to search for free blocks. This had a restriction of only being
able to search for aligned extents of free blocks. As a result the
allocation patterns when reserving blocks were suboptimal when the
existing allocation of blocks for an inode was not aligned to the same
boundary.

This patch resolves that problem by adding the ability for gfs2_rbm_find
to search for extents of a particular minimum size. We can then use
gfs2_rbm_find for both looking for reservations, and also looking for
free blocks on an individual basis when we actually come to do the
allocation later on. As a result we only need a single set of code
to deal with both situations.

The function gfs2_rbm_from_block() is moved up rgrp.c so that it
occurs before all of its callers.

Many thanks are due to Bob for helping track down the final issue in
this patch. That fix to the rb_tree traversal and to not share
block reservations from a dirctory to its children is included here.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

GFS2: Stop block extents at the end of bitmaps

This patch stops multiple block allocations if a nonzero
return code is received from gfs2_rbm_from_block. Without
this patch, if enough pressure is put on the file system,
you get a kernel warning quickly followed by:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffffa04f47e8>] gfs2_alloc_blocks+0x2c8/0x880 [gfs2]
With this patch, things run normally.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fix unclaimed_blocks() wrapping bug and clean up

When rgd->rd_free_clone is less than rgd->rd_reserved, the
unclaimed_blocks() calculation would wrap and produce
incorrect results. This patch checks for this condition
when this function is called from gfs2_mblk_search()

In addition, the use of this particular function in other
places in the code has been dropped by means of a general
clean up of gfs2_inplace_reserve(). This function is now
much easier to follow.

Also the setting of the rgd->rd_last_alloc field is corrected.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Improve block reservation tracing

This patch improves the tracing of block reservations by
removing some corner cases and also providing more useful
detail in the traces.

A new field is added to the reservation structure to contain
the inode number. This is used since in certain contexts it is
not possible to access the inode itself to obtain this information.
As a result we can then display the inode number for all tracepoints
and also in case we dump the resource group.

The "del" tracepoint operation has been removed. This could be called
with the reservation rgrp set to NULL. That resulted in not printing
the device number, and thus making the information largely useless
anyway. Also, the conditional on the rgrp being NULL can then be
removed from the tracepoint. After this change, all the block
reservation tracepoint calls will be called with the rgrp information.

The existing ins,clm and tdel calls to the block reservation tracepoint
are sufficient to track the entire life of the block reservation.

In gfs2_block_alloc() the error detection is updated to print out
the inode number of the problematic inode. This can then be compared
against the information in the glock dump,tracepoints, etc.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fall back to ignoring reservations, if there are no other blocks left

When we get to the stage of allocating blocks, we know that the
resource group in question must contain enough free blocks, otherwise
gfs2_inplace_reserve() would have failed. So if we are left with only
free blocks which are reserved, then we must use those. This can happen
if another node has sneeked in and use some blocks reserved on this
node, for example. Generally this will happen very rarely and only
when the resouce group is nearly full.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Use rbm for gfs2_setbit()

Use the rbm structure for gfs2_setbit() in order to simplify the
arguments to the function. We have to add a bool to control whether
the clone bitmap should be updated (if it exists) but otherwise it
is a more or less direct substitution.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Use rbm for gfs2_testbit()

Change the arguments to gfs2_testbit() so that it now just takes an
rbm specifying the position of the two bit entry to return.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Eliminate unnecessary check for state > 3 in bitfit

Function gfs2_bitfit was checking for state > 3, but that's
impossible since it is only called from rgblk_search, which receives
only GFS2_BLKST_ constants.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: rbm code cleanup

This patch fixes a few small rbm related things. First, it fixes
a corner case where the rbm needs to switch bitmaps and wasn't
adjusting its buffer pointer. Second, there's a white space issue
fixed. Third, the logic in function gfs2_rbm_from_block was optimized
a bit. Lastly, a check for goal block overflows was added to function
gfs2_alloc_blocks.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fix case where reservation finished at end of rgrp

One corner case which the original patch failed to take into
account was when there is a reservation which ended such that
the following block was one beyond the end of the rgrp in
question. This extra test fixes that case.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Reported-by: Bob Peterson <rpeterso@redhat.com>
Tested-by: Bob Peterson <rpeterso@redhat.com>

GFS2: Use RB_CLEAR_NODE() rather than rb_init_node()

gfs2 calls RB_EMPTY_NODE() to check if nodes are not on an rbtree.
The corresponding initialization function is RB_CLEAR_NODE().
rb_init_node() was never clearly defined and is going away.

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Update rgblk_free() to use rbm

Replace open coded version with a call to gfs2_rbm_from_block()

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Update gfs2_get_block_type() to use rbm

Use the new gfs2_rbm_from_block() function to replace an open
coded version of the same code.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Replace rgblk_search with gfs2_rbm_find

This is part of a series of patches which are introducing the
gfs2_rbm structure throughout the block allocation code. The
main aim of this part is to create a search function which can
deal directly with struct gfs2_rbm. In this case it specifies
the initial position at which to start the search and also the
point at which the search terminates.

The net result of this is to clean up the search code and make
it rather more readable, and the various possible exceptions which
may occur during the search are partitioned into their own functions.

There are some bug fixes too. We should not be checking the reservations
while allocating extents - the time for that is when we are searching
for where to put the extent, not when we've already made that decision.

Also, rgblk_search had two uses, and in only one of those cases did
it make sense to check for reservations. This is fixed in the new
gfs2_rbm_find function, which has a cleaner interface.

The reservation checking has been improved by always checking for
contiguous reservations, and returning the first free block after
all contiguous reservations. This is done under the spin lock to
ensure consistancy of the tree.

The allocation of extents is now in all cases done by the existing
allocation code, and if there is an active reservation, that is updated
after the fact. Again this is done under the spin lock, since it entails
changing the lookup key for the reservation in question.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Add structure to contain rgrp, bitmap, offset tuple

This patch introduces a new structure, gfs2_rbm, which is a
tuple of a resource group, a bitmap within the resource group
and an offset within that bitmap. This is designed to make
manipulating these sets of variables easier. There is also a
new helper function which converts this representation back
to a disk block address.

In addition, the rbtree nodes which are used for the reservations
were not being correctly initialised, which is now fixed. Also,
the tracing was not passing through the inode where it should
have been. That is mostly fixed aside from one corner case. This
needs to be revisited since there can also be a NULL rgrp in
some cases which results in the device being incorrect in the
trace.

This is intended to be the first step towards cleaning up some
of the allocation code, and some further bug fixes.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Remove rs_requested field from reservations

The rs_requested field is left over from the original allocation
code, however this should have been a parameter passed to the
various functions from gfs2_inplace_reserve() and not a member of the
reservation structure as the value is not required after the
initial allocation.

This also helps simplify the code since we no longer need to set
the rs_requested to zero. Also the gfs2_inplace_release()
function can also be simplified since the reservation structure
will always be defined when it is called, and the only remaining
task is to unlock the rgrp if required. It can also now be
called unconditionally too, resulting in a further simplification.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Take account of blockages when using reserved blocks

The claim_reserved_blks() function was not taking account of
the possibility of "blockages" while performing allocation.
This can be caused by another node allocating something in
the same extent which has been reserved locally.

This patch tests for this condition and then skips the remainder
of the reservation in this case. This is a relatively rare event,
so that it should not affect the general performance improvement
which the block reservations provide.

The claim_reserved_blks() function also appears not to be able
to deal with reservations which cross bitmap boundaries, but
that can be dealt with in a future patch since we don't generate
boundary crossing reservations currently.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Reported-by: David Teigland <teigland@redhat.com>
Cc: Bob Peterson <rpeterso@redhat.com>

GFS2: Reduce file fragmentation

This patch reduces GFS2 file fragmentation by pre-reserving blocks. The
resulting improved on disk layout greatly speeds up operations in cases
which would have resulted in interlaced allocation of blocks previously.
A typical example of this is 10 parallel dd processes, each writing to a
file in a common dirctory.

The implementation uses an rbtree of reservations attached to each
resource group (and each inode).

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: kernel panic with small gfs2 filesystems - 1 RG

In the unlikely setup where there's only one resource group in the gfs2
filesystem, gfs2_rgrpd_get_next() returns a NULL rgd that is not dealt with
properly, causing a kernel NULL ptr dereference. This patch fixes this issue.

Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Combine functions get_local_rgrp and gfs2_inplace_reserve

This function combines rgrp functions get_local_rgrp and
gfs2_inplace_reserve so that the double retry loop is gone.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Use lvbs for storing rgrp information with mount option

Instead of reading in the resource groups when gfs2 is checking
for free space to allocate from, gfs2 can store the necessary infromation
in the resource group's lvb. Also, instead of searching for unlinked
inodes in every resource group that's checked for free space, gfs2 can
store the number of unlinked but inodes in the lvb, and only check for
unlinked inodes if it will find some.

The first time a resource group is locked, the lvb must initialized.
Since this involves counting the unlinked inodes in the resource group,
this takes a little extra time. But after that, if the resource group
is locked with GL_SKIP, the buffer head won't be read in unless it's
actually needed.

Enabling the resource groups lvbs is done via the rgrplvb mount option. If
this option isn't set, the lvbs will still be set and updated, but they won't
be verfied or used by the filesystem. To safely turn on this option, all of
the nodes mounting the filesystem must be running code with this patch, and
the filesystem must have been completely unmounted since they were updated.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fold quota data into the reservations struct

This patch moves the ancillary quota data structures into the
block reservations structure. This saves GFS2 some time and
effort in allocating and deallocating the qadata structure.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Extend the life of the reservations

This patch lengthens the lifespan of the reservations structure for
inodes. Before, they were allocated and deallocated for every write
operation. With this patch, they are allocated when the first write
occurs, and deallocated when the last process closes the file.
It's more efficient to do it this way because it saves GFS2 a lot of
unnecessary allocates and frees. It also gives us more flexibility
for the future: (1) we can now fold the qadata structure back into
the structure and save those alloc/frees, (2) we can use this for
multi-block reservations.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Add rgrp information to block_alloc trace point

This is a second attempt at a patch that adds rgrp information to the
block allocation trace point for GFS2. As suggested, the patch was
modified to list the rgrp information _after_ the fields that exist today.

Again, the reason for this patch is to allow us to trace and debug
problems with the block reservations patch, which is still in the works.
We can debug problems with reservations if we can see what block allocations
result from the block reservations. It may also be handy in figuring out
if there are problems in rgrp free space accounting. In other words,
we can use it to track the rgrp and its free space along side the allocations
that are taking place.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Eliminate needless parameter from function gfs2_setbit

This patch eliminates parameter "buf1" from function gfs2_setbit.
This is possible because it was always passed in as bi->bi_bh->b_data.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Remove unused argument from gfs2_internal_read

gfs2_internal_read accepts an unused ra_state argument, left over from
when we did readahead on the rindex. Since there are currently no plans
to add back this readahead, this patch removes the ra_state parameter
and updates the functions which call gfs2_internal_read accordingly.

Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Change variable blk to biblk

In the resource group code, we have no less than three different
kinds of block references: block relative to the file system (u64),
block relative to the rgrp (u32), and block relative to the bitmap.
This is a small step to making the code more readable; it renames
variable blk to biblk to solidify in my mind that it's relative to
the bitmap and nothing else.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fix function parameter comments in rgrp.c

This patch just fixes a bunch of function parameter comments.
Slowly, over the years, the comments have gotten out of date
(mostly my fault, as I haven't been good at keeping them up to date).
This patch rectifies some of that.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Eliminate offset parameter to gfs2_setbit

This patch eliminates a redundant parameter.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Use slab for block reservation memory

This patch changes block reservations so it uses slab storage.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Make sure rindex is uptodate before starting transactions

This patch removes the call from gfs2_blk2rgrd to function
gfs2_rindex_update and replaces it with individual calls.
The former way turned out to be too problematic.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: put glock reference in error patch of read_rindex_entry

This patch fixes the error path of function read_rindex_entry
so that it correctly gives up its glock reference in cases where
there is a race to re-read the rindex after gfs2_grow.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: make sure rgrps are up to date in func gfs2_blk2rgrpd

This patch adds a call to gfs2_rindex_update from function gfs2_blk2rgrpd
and removes calls to it that are made redundant by it. The problem is
that a gfs2_grow can add rgrps to the rindex, then put those rgrps into
use, thus rendering the rindex we read in at mount time incomplete.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Eliminate sd_rindex_mutex

Over time, we've slowly eliminated the use of sd_rindex_mutex.
Up to this point, it was only used in two places: function
gfs2_ri_total (which totals the file system size by reading
and parsing the rindex file) and function gfs2_rindex_update
which updates the rgrps in memory. Both of these functions have
the rindex glock to protect them, so the rindex is unnecessary.
Since gfs2_grow writes to the rindex via the meta_fs, the mutex
is in the wrong order according to the normal rules. This patch
eliminates the mutex entirely to avoid the problem.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Unlock rindex mutex on glock error

This patch fixes an error path in function gfs2_rindex_update
that leaves the rindex mutex held.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: FITRIM ioctl support

The FITRIM ioctl provides an alternative way to send discard requests to
the underlying device. Using the discard mount option results in every
freed block generating a discard request to the block device. This can
be slow, since many block devices can only process discard requests of
larger sizes, and also such operations can be time consuming.

Rather than using the discard mount option, FITRIM allows a sweep of the
filesystem on an occasional basis, and also to optionally avoid sending
down discard requests for smaller regions.

In GFS2 FITRIM will work at resource group granularity. There is a flag
for each resource group which keeps track of which resource groups have
been trimmed. This flag is reset whenever a deallocation occurs in the
resource group, and set whenever a successful FITRIM of that resource
group has taken place. This helps to reduce repeated discard requests
for the same block ranges, again improving performance.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Read resource groups on mount

This makes mount take slightly longer, but at the same time, the first
write to the filesystem will be faster too. It also means that if there
is a problem in the resource index, then we can refuse to mount rather
than having to try and report that when the first write occurs.

In addition, to avoid recursive locking, we hvae to take account of
instances when the rindex glock may already be held when we are
trying to update the rbtree of resource groups.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fix a use-after-free that coverity spotted

In function gfs2_inplace_release it was trying to unlock a gfs2_holder
structure associated with a reservation, after said reservation was
freed. The problem is that the statements have the wrong order.
This patch corrects the order so that the reservation is freed after
the gfs2_holder is unlocked.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fix multi-block allocation

Clean up gfs2_alloc_blocks so that it takes the full extent length
rather than just the number of non-inode blocks as an argument. That
will only make a difference in the inode allocation case for now.

Also, this fixes the extent length handling around gfs2_alloc_extent() so
that multi block allocations will work again.

The rd_last_alloc block is set to the final block in the allocated
extent (as per the update to i_goal, but referenced to a different
start point).

This also removes the dinode argument to rgblk_search() which is no
longer used.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: decouple quota allocations from block allocations

This patch separates the code pertaining to allocations into two
parts: quota-related information and block reservations.
This patch also moves all the block reservation structure allocations to
function gfs2_inplace_reserve to simplify the code, and moves
the frees to function gfs2_inplace_release.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: split function rgblk_search

This patch splits function rgblk_search into a function that finds
blocks to allocate (rgblk_search) and a function that assigns those
blocks (gfs2_alloc_extent).

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@rehat.com>

GFS2: Fix up "off by one" in the previous patch

The trace point should take extlen and not *ndata as the
extent length.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: move toward a generic multi-block allocator

This patch is a revision of the one I previously posted.
I tried to integrate all the suggestions Steve gave.
The purpose of the patch is to change function gfs2_alloc_block
(allocate either a dinode block or an extent of data blocks)
to a more generic gfs2_alloc_blocks function that can
allocate both a dinode _and_ an extent of data blocks in the
same call. This will ultimately help us create a multi-block
reservation scheme to reduce file fragmentation.

This patch moves more toward a generic multi-block allocator that
takes a pointer to the number of data blocks to allocate, plus whether
or not to allocate a dinode. In theory, it could be called to allocate
(1) a single dinode block, (2) a group of one or more data blocks, or
(3) a dinode plus several data blocks.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: remove vestigial al_alloced

This patch removes the vestigial variable al_alloced from
the gfs2_alloc structure. This is another baby step toward
multi-block reservations.

My next planned step is to decouple the quota variables
from the gfs2_alloc structure so we can use a different
method for allocations.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: combine gfs2_alloc_block and gfs2_alloc_di

GFS2 functions gfs2_alloc_block and gfs2_alloc_di do basically
the same things, with a few exceptions. This patch combines
the two functions into a slightly more generic gfs2_alloc_block.
Having one centralized block allocation function will reduce
code redundancy and make it easier to implement multi-block
reservations to reduce file fragmentation in the future.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Add non-try locks back to get_local_rgrp

This upstream patch had what I believe is an unintended consequence:

http://git.kernel.org/?p=linux/kernel/git/steve/gfs2-3.0-nmw.git;a=commitdiff;h=beca42486749c1538a5ed58fe9dcc9f26d428c93

The patch changed function get_local_rgrp such that it ONLY
used TRY locks for RGRP searches. Prior to that patch, the code
used TRY locks during the first loop, and if that was unsuccessful,
it used normal blocking locks on subsequent searches. This patch
changes it back to the old way.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Remove two unused variables

The two variables being initialised in gfs2_inplace_reserve
to track the file & line number of the caller are never
used, so we might as well remove them.

If something does go wrong, then a stack trace is probably
more useful anyway.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fix off-by-one in gfs2_blk2rgrpd

Bob reported:

I found an off-by-one problem with how I coded this section:
It should be:

+ else if (blk >= cur->rd_data0 + cur->rd_data)

In fact, cur->rd_data0 + cur->rd_data is the start of the next
rgrp (the next ri_addr), so without the "=" check it can land on
the wrong rgrp.

In all normal cases, this won't be a problem: you're searching
for a block _within_ the rgrp, which will pass the test properly.
Where it gets into trouble is if you search the rgrps for the
block exactly equal to ri_addr. I don't think anything in the
kernel does this, but I found a place in gfs2-utils gfs2_edit
where it does. So I definitely need to fix it in libgfs2. I'd
like to suggest we fix it in the kernel as well for the sake of
keeping the functions similar.

So this patch fixes the above mentioned off by one error as well
as removing the unused parent pointer.

Reported-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Correctly set goal block after allocation

The new goal block should be set to the end of the newly
allocated extent, not the start of it.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Use cached rgrp in gfs2_rlist_add()

Each block which is deallocated, requires a call to gfs2_rlist_add()
and each of those calls was calling gfs2_blk2rgrpd() in order to
figure out which rgrp the block belonged in. This can be speeded up
by making use of the rgrp cached in the inode. We also reset this
cached rgrp in case the block has changed rgrp. This should provide
a big reduction in gfs2_blk2rgrpd() calls during deallocation.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Remove obsolete assert

Given that a resource group has been locked, there is no reason why
we should not be able to allocate as many blocks as are free. The
al_requested parameter should really be considered as a minimum
number of blocks to be available. Should this limit be overshot,
there are other mechanisms which will prevent over allocation.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Cache the most recently used resource group in the inode

This means that after the initial allocation for any inode, the
last used resource group is cached in the inode for future use.
This drastically reduces the number of lookups of resource
groups in the common case, and this the contention on that
data structure.

The allocation algorithm is the same as previously, except that we
always check to see if the goal block is within the cached rgrp
first before going to the rbtree to look one up.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Make resource groups "append only" during life of fs

Since we have ruled out supporting online filesystem shrink,
it is possible to make the resource group list append only
during the life of a super block. This gives several benefits:

Firstly, we only need to read new rindex elements as they are added
rather than needing to reread the whole rindex file each time one
element is added.

Secondly, the rindex glock can be held for much shorter periods of
time, and is completely removed from the fast path for allocations.
The lock is taken in shared mode only when updating the resource
groups when the first allocation occurs, and after a grow has
taken place.

Thirdly, this results in a reduction in code size, and everything
gets a lot simpler to understand in this area.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Use rbtree for resource groups and clean up bitmap buffer ref count scheme

Here is an update of Bob's original rbtree patch which, in addition, also
resolves the rather strange ref counting that was being done relating to
the bitmap blocks.

Originally we had a dual system for journaling resource groups. The metadata
blocks were journaled and also the rgrp itself was added to a list. The reason
for adding the rgrp to the list in the journal was so that the "repolish
clones" code could be run to update the free space, and potentially send any
discard requests when the log was flushed. This was done by comparing the
"cloned" bitmap with what had been written back on disk during the transaction
commit.

Due to this, there was a requirement to hang on to the rgrps' bitmap buffers
until the journal had been flushed. For that reason, there was a rather
complicated set up in the ->go_lock ->go_unlock functions for rgrps involving
both a mutex and a spinlock (the ->sd_rindex_spin) to maintain a reference
count on the buffers.

However, the journal maintains a reference count on the buffers anyway, since
they are being journaled as metadata buffers. So by moving the code which deals
with the post-journal accounting for bitmap blocks to the metadata journaling
code, we can entirely dispense with the rather strange buffer ref counting
scheme and also the requirement to journal the rgrps.

The net result of all this is that the ->sd_rindex_spin is left to do exactly
one job, and that is to look after the rbtree or rgrps.

This patch is designed to be a stepping stone towards using RCU for the rbtree
of resource groups, however the reduction in the number of uses of the
->sd_rindex_spin is likely to have benefits for multi-threaded workloads,
anyway.

The patch retains ->go_lock and ->go_unlock for rgrps, however these maybe also
be removed in future in favour of calling the functions directly where required
in the code. That will allow locking of resource groups without needing to
actually read them in - something that could be useful in speeding up statfs.

In the mean time though it is valid to dereference ->bi_bh only when the rgrp
is locked. This is basically the same rule as before, modulo the references not
being valid until the following journal flush.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Cc: Benjamin Marzinski <bmarzins@redhat.com>

GFS2: combine duplicated block freeing routines

__gfs2_free_data and __gfs2_free_meta are almost identical, and
can be trivially combined.

[This is as per Eric's original patch minus gfs2_free_data() which had
no callers left and plus the conversion of the bmap.c calls to these
functions. All in all, a nice clean up]

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Wipe directory hash table metadata when deallocating a directory

The deallocation code for directories in GFS2 is largely divided into
two parts. The first part deallocates any directory leaf blocks and
marks the directory as being a regular file when that is complete. The
second stage was identical to deallocating regular files.

Regular files have their data blocks in a different
address space to directories, and thus what would have been normal data
blocks in a regular file (the hash table in a GFS2 directory) were
deallocated correctly. However, a reference to these blocks was left in the
journal (assuming of course that some previous activity had resulted in
those blocks being in the journal or ail list).

This patch uses the i_depth as a test of whether the inode is an
exhash directory (we cannot test the inode type as that has already
been changed to a regular file at this stage in deallocation)

The original issue was reported by Chris Hertel as an issue he encountered
running bonnie++

Reported-by: Christopher R. Hertel <crh@samba.org>
Cc: Abhijith Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Alter point of entry to glock lru list for glocks with an address_space

Rather than allowing the glocks to be scheduled for possible
reclaim as soon as they have exited the journal, this patch
delays their entry to the list until the glocks in question
are no longer in use.

This means that we will rely on the vm for writeback of all
dirty data and metadata from now on. When glocks are added
to the lru list they should be freeable much faster since all
the I/O required to free them should have already been completed.

This should lead to much better I/O patterns under low memory
conditions.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Dump better debug info if a bitmap inconsistency is detected

On rare occasions we encounter gfs2 problems where an
invalid bitmap state transition is attempted. For example,
trying to "unlink" a free block. In these cases, there
is really no useful information logged to debug the problem.
This patch adds more debug details that should allow us to
more closely examine the problem and possibly solve it.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: filesystem hang caused by incorrect lock order

This patch fixes a deadlock in GFS2 where two processes are trying
to reclaim an unlinked dinode:
One holds the inode glock and calls gfs2_lookup_by_inum trying to look
up the inode, which it can't, due to I_FREEING. The other has set
I_FREEING from vfs and is at the beginning of gfs2_delete_inode
waiting for the glock, which is held by the first. The solution is to
add a new non_block parameter to the gfs2_iget function that causes it
to return -ENOENT if the inode is being freed.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: deallocation performance patch

This patch is a performance improvement to GFS2's dealloc code.
Rather than update the quota file and statfs file for every
single block that's stripped off in unlink function do_strip,
this patch keeps track and updates them once for every layer
that's stripped. This is done entirely inside the existing
transaction, so there should be no risk of corruption.
The other functions that deallocate blocks will be unaffected
because they are using wrapper functions that do the same
thing that they do today.

I tested this code on my roth cluster by creating 200
files in a directory, each of which is 100MB, then on
four nodes, I simultaneously deleted the files, thus competing
for GFS2 resources (but different files). The commands
I used were:

[root@roth-01]# time for i in `seq 1 4 200` ; do rm /mnt/gfs2/bigdir/gfs2.$i; done
[root@roth-02]# time for i in `seq 2 4 200` ; do rm /mnt/gfs2/bigdir/gfs2.$i; done
[root@roth-03]# time for i in `seq 3 4 200` ; do rm /mnt/gfs2/bigdir/gfs2.$i; done
[root@roth-05]# time for i in `seq 4 4 200` ; do rm /mnt/gfs2/bigdir/gfs2.$i; done

The performance increase was significant:

roth-01 roth-02 roth-03 roth-05
--------- --------- --------- ---------
old: real 0m34.027 0m25.021s 0m23.906s 0m35.646s
new: real 0m22.379s 0m24.362s 0m24.133s 0m18.562s

Total time spent deleting:
old: 118.6s
new: 89.4

For this particular case, this showed a 25% performance increase for
GFS2 unlinks.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: fsck.gfs2 reported statfs error after gfs2_grow

When you do gfs2_grow it failed to take the very last
rgrp into account when adding up the new free space due
to an off-by-one error. It was not reading the last
rgrp from the rindex because of a check for "<=" that
should have been "<". Therefore, fsck.gfs2 was finding
(and fixing) an error with the system statfs file.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

GFS2: fix recursive locking during rindex truncates

When you truncate the rindex file, you need to avoid calling gfs2_rindex_hold,
since you already hold it. However, if you haven't already read in the
resource groups, you need to do that.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: reread rindex when necessary to grow rindex

When GFS2 grew the filesystem, it was never rereading the rindex file during
the grow. This is necessary for large grows when the filesystem is almost full,
and GFS2 needs to use some of the space allocated earlier in the grow to
complete it. Now, if GFS2 fails to reserve the necessary space and the rindex
file is not uptodate, it rereads it. Also, the only difference between
gfs2_ri_update() and gfs2_ri_update_special() was that gfs2_ri_update_special()
didn't clear out the existing resource groups, since you knew that it was only
called when there were no resource groups. Attempting to clear out the
resource groups when there are none takes almost no time, and rarely happens,
so I simply removed gfs2_ri_update_special().

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fix inode deallocation race

This area of the code has always been a bit delicate due to the
subtleties of lock ordering. The problem is that for "normal"
alloc/dealloc, we always grab the inode locks first and the rgrp lock
later.

In order to ensure no races in looking up the unlinked, but still
allocated inodes, we need to hold the rgrp lock when we do the lookup,
which means that we can't take the inode glock.

The solution is to borrow the technique already used by NFS to solve
what is essentially the same problem (given an inode number, look up
the inode carefully, checking that it really is in the expected
state).

We cannot do that directly from the allocation code (lock ordering
again) so we give the job to the pre-existing delete workqueue and
carry on with the allocation as normal.

If we find there is no space, we do a journal flush (required anyway
if space from a deallocation is to be released) which should block
against the pending deallocations, so we should always get the space
back.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2 fatal: filesystem consistency error on rename

This patch fixes a GFS2 problem whereby the first rename after a
mount can result in a file system consistency error being flagged
improperly and cause the file system to withdraw. The problem is
that the rename code tries to run the rgrp list with function
gfs2_blk2rgrpd before the rgrp list is guaranteed to be read in
from disk. The patch makes the rename function hold the rindex
glock (as the gfs2_unlink code does today) which reads in the rgrp
list if need be. There were a total of three places in the rename
code that improperly referenced the rgrp list without the rindex
glock and this patch fixes all three.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: fallocate support

This patch adds support for fallocate to gfs2. Since the gfs2 does not support
uninitialized data blocks, it must write out zeros to all the blocks. However,
since it does not need to lock any pages to read from, gfs2 can write out the
zero blocks much more efficiently. On a moderately full filesystem, fallocate
works around 5 times faster on average. The fallocate call also allows gfs2 to
add blocks to the file without changing the filesize, which will make it
possible for gfs2 to preallocate space for the rindex file, so that gfs2 can
grow a completely full filesystem.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Add a bug trap in allocation code

This adds a check to ensure that if we reach the block allocator
that we don't try and proceed if there is no alloc structure
hanging off the inode. This should only happen if there is a bug
in GFS2. The error return code is distinctive in order that it
will be easily spotted.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Remove i_disksize

With the update of the truncate code, ip->i_disksize and
inode->i_size are merely copies of each other. This means
we can remove ip->i_disksize and use inode->i_size exclusively
reducing the size of a GFS2 inode by 8 bytes.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

block: remove BLKDEV_IFL_WAIT

All the blkdev_issue_* helpers can only sanely be used for synchronous
caller. To issue cache flushes or barriers asynchronously the caller needs
to set up a bio by itself with a completion callback to move the asynchronous
state machine ahead. So drop the BLKDEV_IFL_WAIT flag that is always
specified when calling blkdev_issue_* and also remove the now unused flags
argument to blkdev_issue_flush and blkdev_issue_zeroout. For
blkdev_issue_discard we need to keep it for the secure discard flag, which
gains a more descriptive name and loses the bitops vs flag confusion.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

gfs2: replace barriers with explicit flush / FUA usage

Switch to the WRITE_FLUSH_FUA flag for log writes, remove the EOPNOTSUPP
detection for barriers and stop setting the barrier flag for discards.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

GFS2: Rework reclaiming unlinked dinodes

The previous patch I wrote for reclaiming unlinked dinodes
had some shortcomings and did not prevent all hangs.
This version is much cleaner and more logical, and has
passed very difficult testing. Sorry for the churn.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: stuck in inode wait, no glocks stuck

This patch changes the lock ordering when gfs2 reclaims
unlinked dinodes, thereby avoiding a livelock.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

blkdev: generalize flags for blkdev_issue_fn functions

The patch just convert all blkdev_issue_xxx function to common
set of flags. Wait/allocation semantics preserved.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

GFS2: glock livelock

This patch fixes a couple gfs2 problems with the reclaiming of
unlinked dinodes. First, there were a couple of livelocks where
everything would come to a halt waiting for a glock that was
seemingly held by a process that no longer existed. In fact, the
process did exist, it just had the wrong pid number in the holder
information. Second, there was a lock ordering problem between
inode locking and glock locking. Third, glock/inode contention
could sometimes cause inodes to be improperly marked invalid by
iget_failed.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

GFS2: Use GFP_NOFS for alloc structure

This is called under a glock, so its a good plan to use GFP_NOFS

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fix previous patch

The do_div() call needs to remain.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Don't withdraw on partial rindex entries

ince gfs2 writes the rindex file a block at a time, and releases the
exclusive lock after each block, it is possible that another process
will grab the lock in the middle of the write. Since rindex entries are
not an even divisor of blocks, that other process may see partial
entries. On grows, this is fine. The process can simply ignore the the
partial entires. Previously, the code withdrew when it saw partial
entries. Now it simply ignores them.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Locking order fix in gfs2_check_blk_state

In some cases we already have the rindex lock when
we enter this function.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

trivial: fix typo "to to" in multiple files

Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

GFS2: Whitespace fixes

Reported-by: Daniel Walker <dwalker@fifo99.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

block: use blkdev_issue_discard in blk_ioctl_discard

blk_ioctl_discard duplicates large amounts of code from blkdev_issue_discard,
the only difference between the two is that blkdev_issue_discard needs to
send a barrier discard request and blk_ioctl_discard a non-barrier one,
and blk_ioctl_discard needs to wait on the request. To facilitates this
add a flags argument to blkdev_issue_discard to control both aspects of the
behaviour. This will be very useful later on for using the waiting
funcitonality for other callers.

Based on an earlier patch from Matthew Wilcox <matthew@wil.cx>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

GFS2: Be extra careful about deallocating inodes

There is a potential race in the inode deallocation code if two
nodes try to deallocate the same inode at the same time. Most of
the issue is solved by the iopen locking. There is still a small
window which is not covered by the iopen lock. This patches fixes
that and also makes the deallocation code more robust in the face of
any errors in the rgrp bitmaps, or erroneous iopen callbacks from
other nodes.

This does introduce one extra disk read, but that is generally not
an issue since its the same block that must be written to later
in the deallocation process. The total disk accesses therefore stay
the same,

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Remove no_formal_ino generating code

The inum structure used throughout GFS2 has two fields. One
no_addr is the disk block number of the inode in question and
is used everywhere as the inode number. The other, no_formal_ino,
is used only as the generation number for NFS.

Historically the no_formal_ino field was set using a complicated
system of one global and one per-node file containing inode numbers
in order to ensure that each no_formal_ino was unique. Also this
code made no provision for what would happen when eventually the
(64 bit) numbers ran out. Now I know that is pretty unlikely to
happen given the large space of numbers, but it is possible
nevertheless.

The only guarantee required for no_formal_ino is that, for any
single inode, the same number doesn't get reused too quickly.

We already have a generation number which is kept in the inode
and initialised from a counter in the resource group (almost
no overhead, since we have to touch the resource group anyway
in order to allocate an inode in the first place). Aside from
ensuring that we never use the value 0 in the no_formal_ino
field, we can use that counter directly.

As a result of that change, we lose about 200 lines of code and
also gain about 10 creates/sec on the postmark benchmark (on
my test machine).

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Replace assertion with proper error handling

One fewer assert, one more place we can recover gracefully
if there is an error.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Improve error handling in inode allocation

A little while back, block allocation was given some improved
error handling which meant that -EIO was returned in the case
of there being a problem in the resource group data. In addition
a message is printed explaning what went wrong and how to fix it.
This extends that error handling so that it also covers inode
allocation too.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fix incorrent statfs consistency check

Since both linked and unlinked inodes are counted by rgd->rd_dinodes, It
makes no sense to count them with the used data blocks (first check that
I changed), it makes sense to count them with the linked inodes (second
check), and it makes no sense to care if there are more unlinked inodes
than linked ones. This fixes these errors.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Don't try and dealloc own inode

When searching for unlinked, but still allocated inodes during block
allocation, avoid the block relating to the inode that is doing the
allocation. This fixes a hang caused when an unlinked, but still
open, inode tries to allocate some more blocks and lands up
finding itself during the search for deallocatable inodes.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Add tracepoints

This patch adds the ability to trace various aspects of the GFS2
filesystem. The trace points are divided into three groups,
glocks, logging and bmap. These points have been chosen because
they allow inspection of the major internal functions of GFS2
and they are also generic enough that they are unlikely to need
any major changes as the filesystem evolves.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

block: Do away with the notion of hardsect_size

Until now we have had a 1:1 mapping between storage device physical
block size and the logical block sized used when addressing the device.
With SATA 4KB drives coming out that will no longer be the case. The
sector size will be 4KB but the logical block size will remain
512-bytes. Hence we need to distinguish between the physical block size
and the logical ditto.

This patch renames hardsect_size to logical_block_size.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

GFS2: Clean up some file names

This patch renames the ops_*.c files which have no counterpart
without the ops_ prefix in order to shorten the name and make
it more readable. In addition, ops_address.h (which was very
small) is moved into inode.h and inode.h is cleaned up by
adding extern where required.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Be more aggressive in reclaiming unlinked inodes

This patch increases the frequency with which gfs2 looks
for unlinked, but still allocated inodes. Its the equivalent
operation to ext3's orphan list, but done with bitmaps in
the resource groups.

This also fixes a bug where a field in the rgrp was too small.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Add a rgrp bitmap full flag

During block allocation, it is useful to know if sections of disk
are full on a finer grained basis than a single resource group.
This can make a performance difference when resource groups have
larger numbers of bitmap blocks, since we no longer have to search
them all block by block in each individual bitmap.

The full flag is set on a per-bitmap basis when it has been
searched and found to have no free space. It is then skipped in
subsequent searches until the flag is reset. The resetting
occurs if we have to drop the glock on the resource group for any
reason, or if we deallocate some blocks within that resource
group and thus free up some space.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Improve resource group error handling

This patch improves the error handling in the case where we
discover that the summary information in the resource group
doesn't match the bitmap information while in the process of
allocating blocks. Originally this resulted in a kernel bug,
but this patch changes that so that we return -EIO and print
some messages explaining what went wrong, and how to fix it.

We also remember locally not to try and allocate from the
same rgrp again, so that a subsequent allocation in a
different rgrp should succeed.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Ensure that the inode goal block settings are updated

GFS2 has a goal block associated with each inode indicating the
search start position for future block allocations (in fact there
are two, but thats for backward compatibility with GFS1 as they
are set to identical locations in GFS2).

In some circumstances, depending on the ordering of updates to
the inode it was possible for the goal block settings to not
be updated on disk. This patch ensures that the goal block will
always get updated, thus reducing the potential for searching
the same (already allocated) blocks again when looking for free
space during block allocation.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fix bug in block allocation

The new bitfit algorithm was counting from the wrong end of
64 bit words in the bitfield. This fixes it by using __ffs64
instead of fls64

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: fix sparse warning: Should it be static?

Impact: Make symbol static.

Fix this sparse warning:
fs/gfs2/rgrp.c:188:5: warning: symbol 'gfs2_bitfit' was not declared. Should it be static?

Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: fix sparse warnings: constant is so big it is ...

Fix this sparse warnings:
fs/gfs2/rgrp.c:156:23: warning: constant 0xffffffffffffffff is so big it is unsigned long long
fs/gfs2/rgrp.c:157:23: warning: constant 0xaaaaaaaaaaaaaaaa is so big it is unsigned long long
fs/gfs2/rgrp.c:158:23: warning: constant 0x5555555555555555 is so big it is long long
fs/gfs2/rgrp.c:194:20: warning: constant 0x5555555555555555 is so big it is long long
fs/gfs2/rgrp.c:204:44: warning: constant 0x5555555555555555 is so big it is long long

Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Fix alignment issue and tidy gfs2_bitfit

An alignment issue with the existing bitfit algorithm was reported
on IA64. This patch attempts to fix that, and also to tidy up the
code a bit. There is now more documentation about how this works
and it has survived a number of different tests.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Add a "demote a glock" interface to sysfs

This adds a sysfs file called demote_rq to GFS2's
per filesystem directory. Its possible to use this
file to demote arbitrary glocks in exactly the same
way as if a request had come in from a remote node.

This is intended for testing issues relating to caching
of data under glocks. Despite that, the interface is
generic enough to send requests to any type of glock,
but be careful as its not always safe to send an
arbitrary message to an arbitrary glock. For that reason
and to prevent DoS, this interface is restricted to root
only.

The messages look like this:

<type>:<glocknumber> <mode>

Example:

echo -n "2:13324 EX" >/sys/fs/gfs2/unity:myfs/demote_rq

Which means "please demote inode glock (type 2) number 13324 so that
I can get an EX (exclusive) lock". The lock modes are those which
would normally be sent by a remote node in its callback so if you
want to unlock a glock, you use EX, to demote to shared, use SH or PR
(depending on whether you like GFS2 or DLM lock modes better!).

If the glock doesn't exist, you'll get -ENOENT returned. If the
arguments don't make sense, you'll get -EINVAL returned.

The plan is that this interface will be used in combination with
the blktrace patch which I recently posted for comments although
it is, of course, still useful in its own right.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Support generation of discard requests

This patch allows GFS2 to generate discard requests for blocks which are
no longer useful to the filesystem (i.e. those which have been freed as
the result of an unlink operation). The requests are generated at the
time which those blocks become available for reuse in the filesystem.

In order to use this new feature, you have to specify the "discard"
mount option. The code coalesces adjacent blocks into a single extent
when generating the discard requests, thus generating the minimum
number.

If an error occurs when the request has been sent to the block device,
then it will print a message and turn off the requests for that
filesystem. If the problem is temporary, then you can use remount to
turn the option back on again. There is also a nodiscard mount option
so that you can use remount to turn discard requests off, if required.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Merge lock_dlm module into GFS2

This is the big patch that I've been working on for some time
now. There are many reasons for wanting to make this change
such as:
o Reducing overhead by eliminating duplicated fields between structures
o Simplifcation of the code (reduces the code size by a fair bit)
o The locking interface is now the DLM interface itself as proposed
some time ago.
o Fewer lookups of glocks when processing replies from the DLM
o Fewer memory allocations/deallocations for each glock
o Scope to do further optimisations in the future (but this patch is
more than big enough for now!)

Please note that (a) this patch relates to the lock_dlm module and
not the DLM itself, that is still a separate module; and (b) that
we retain the ability to build GFS2 as a standalone single node
filesystem with out requiring the DLM.

This patch needs a lot of testing, hence my keeping it I restarted
my -git tree after the last merge window. That way, this has the maximum
exposure before its merged. This is (modulo a few minor bug fixes) the
same patch that I've been posting on and off the the last three months
and its passed a number of different tests so far.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Banish struct gfs2_rgrpd_host

This patch moves the final field so that we can get rid
of struct gfs2_rgrpd_host, as promised some time ago. Also
by rearranging the fields slightly, we are able to reduce
the size of the gfs2_rgrpd structure at the same time.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Move rg_free from gfs2_rgrpd_host to gfs2_rgrpd

The second of three fields which need to move, in order
to remove the struct gfs2_rgrpd_host.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Move rg_igeneration into struct gfs2_rgrpd

This moves one of the fields of struct gfs2_rgrpd_host into
the struct gfs2_rgrpd with the eventual aim of removing
the struct rgrpd_host completely.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

GFS2: Move i_size from gfs2_dinode_host and rename it to i_disksize

This patch moved the i_size field from the gfs2_dinode_host and
following the ext3 convention renames it i_disksize.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

[GFS2] Replace rgrp "recent list" with mru list

This patch removes the "recent list" which is used during allocation
and replaces it with the (already existing) mru list used during
deletion. The "recent list" was not a true mru list leading to a number
of inefficiencies including a "next" function which made scanning the
list an order N^2 operation wrt to the number of list elements.

This should increase allocation performance with large numbers of rgrps.
Its also a useful preparation and cleanup before some further changes
which are planned in this area.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

[GFS2] BUG: unable to handle kernel paging request at ffff81002690e000

This patch fixes bugzilla bug bz448866: gfs2: BUG: unable to
handle kernel paging request at ffff81002690e000.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

[GFS2] Fix cast from unsigned int to s64

This fixes bz 444829 where allocating a new block caused gfs2 file systems to
report 0 bytes used in df. It was caused by a broken cast from an unsigned int
in gfs2_block_alloc() to a negative s64 in gfs2_statfs_change(). This patch
casts the unsigned int to an s64 before the unary minus is applied.

Signed-off-by: Andrew Price <andy@andrewprice.me.uk>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

[GFS2] Faster gfs2_bitfit algorithm

This version of the gfs2_bitfit algorithm includes the latest
suggestions from Steve Whitehouse. It is typically eight to
ten times faster than the version we're using today. If there
is a lot of metadata mixed in (lots of small files) the
algorithm is often 15 times faster, and given the right
conditions, I've seen peaks of 20 times faster.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

[GFS2] Allow bmap to allocate extents

We've supported mapping of extents when no block allocation is required
for some time. This patch extends that to mapping of extents when an
allocation has been requested. In that case we try to allocate as many
blocks as are requested, but we might return fewer in case there is
something preventing us from returning the complete amount (e.g. an
already allocated block is in the way).

Currently the only code path which can actually request multiple data
blocks in a single bmap call is the page_mkwrite path and even then it
only happens if there are multiple blocks per page. What this patch does
do however, is merge the allocation requests for metadata (growing the
metadata tree in either height or depth) with the allocation of the data
blocks in the case that both are needed. This results in lower overheads
even in the single block allocation case.

The one thing which we can't handle here at the moment is unstuffing. I
would like to be able to do that, but the problem which arises is that
in order to unstuff one has to get a locked page from the page cache
which results in locking problems in the (usual) case that the caller is
holding the page lock on the page it wishes to map. So that case will
have to be addressed in future patches.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

[GFS2] Add extent allocation to block allocator

Rather than having to allocate a single block at a time, this patch
allows the block allocator to allocate an extent. Since there is
no difference (so far as the block allocator is concerned) between
data blocks and indirect blocks, it is posible to allocate a single
extent and for the caller to unrevoke just the blocks required
for indirect blocks.

Currently the only bit of GFS2 to make use of this feature is the
build height function. The intention is that gfs2_block_map will
be changed to make use of this feature in future patches.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>