xfs: hook live rmap operations during a repair operation

Hook the regular rmap code when an rmapbt repair operation is running so
that we can unlock the AGF buffer to scan the filesystem and keep the
in-memory btree up to date during the scan.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: create a shadow rmap btree during rmap repair

Create an in-memory btree of rmap records instead of an array. This
enables us to do live record collection instead of freezing the fs.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: repair the rmapbt

Rebuild the reverse mapping btree from all primary metadata. This first
patch establishes the bare mechanics of finding records and putting
together a new ondisk tree; more complex pieces are needed to make it
work properly.

Link: Documentation/filesystems/xfs-online-fsck-design.rst
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: split xfs_inobt_init_cursor

Split xfs_inobt_init_cursor into separate routines for the inobt and
finobt to prepare for the removal of the xfs_btnum global enumeration
of btree types.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

xfs: split xfs_allocbt_init_cursor

Split xfs_allocbt_init_cursor into separate routines for the by-bno
and by-cnt btrees to prepare for the removal of the xfs_btnum global
enumeration of btree types.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

xfs: update health status if we get a clean bill of health

If scrub finds that everything is ok with the filesystem, we need a way
to tell the health tracking that it can let go of indirect health flags,
since indirect flags only mean that at some point in the past we lost
some context.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: repair dquots based on live quotacheck results

Use the shadow quota counters that live quotacheck creates to reset the
incore dquot counters.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: repair cannot update the summary counters when logging quota flags

While running xfs/804 (quota repairs racing with fsstress), I observed a
filesystem shutdown in the primary sb write verifier:

run fstests xfs/804 at 2022-05-23 18:43:48
XFS (sda4): Mounting V5 Filesystem
XFS (sda4): Ending clean mount
XFS (sda4): Quotacheck needed: Please wait.
XFS (sda4): Quotacheck: Done.
XFS (sda4): EXPERIMENTAL online scrub feature in use. Use at your own risk!
XFS (sda4): SB ifree sanity check failed 0xb5 > 0x80
XFS (sda4): Metadata corruption detected at xfs_sb_write_verify+0x5e/0x100 [xfs], xfs_sb block 0x0
XFS (sda4): Unmount and run xfs_repair

The "SB ifree sanity check failed" message was a debugging printk that I
added to the kernel; observe that 0xb5 - 0x80 = 53, which is less than
one inode chunk.

I traced this to the xfs_log_sb calls from the online quota repair code,
which tries to clear the CHKD flags from the superblock to force a
mount-time quotacheck if the repair fails. On a V5 filesystem,
xfs_log_sb updates the ondisk sb summary counters with the current
contents of the percpu counters. This is done without quiescing other
writer threads, which means it could be racing with a thread that has
updated icount and is about to update ifree.

If the other write thread had incremented ifree before updating icount,
the repair thread will write icount > ifree into the logged update. If
the AIL writes the logged superblock back to disk before anyone else
fixes this siutation, this will lead to a write verifier failure, which
causes a filesystem shutdown.

Resolve this problem by updating the quota flags and calling
xfs_sb_to_disk directly, which does not touch the percpu counters.
While we're at it, we can elide the entire update if the selected qflags
aren't set.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: repair the inode core and forks of a metadata inode

Add a helper function to repair the core and forks of a metadata inode,
so that we can get move onto the task of repairing higher level metadata
that lives in an inode.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: refactor repair forcing tests into a repair.c helper

There are a couple of conditions that userspace can set to force repairs
of metadata. These really belong in the repair code and not open-coded
into the check code, so refactor them into a helper.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: repair inode fork block mapping data structures

Use the reverse-mapping btree information to rebuild an inode block map.
Update the btree bulk loading code as necessary to support inode rooted
btrees and fix some bitrot problems.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: repair inode records

If an inode is so badly damaged that it cannot be loaded into the cache,
fix the ondisk metadata and try again. If there /is/ a cached inode,
fix any problems and apply any optimizations that can be solved incore.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: try to attach dquots to files before repairing them

Inode resource usage is tracked in the quota metadata. Repairing a file
might change the resources used by that file, which means that we need
to attach dquots to the file that we're examining before accessing
anything in the file protected by the ILOCK.

However, there's a twist: a dquot cache miss requires the dquot to be
read in from the quota file, during which we drop the ILOCK on the file
being examined. This means that we *must* try to attach the dquots
before taking the ILOCK.

Therefore, dquots must be attached to files in the scrub setup function.
If doing so yields corruption errors (or unknown dquot errors), we
instead clear the quotachecked status, which will cause a quotacheck on
next mount. A future series will make this trigger live quotacheck.

While we're here, change the xrep_ino_dqattach function to use the
unlocked dqattach functions so that we avoid cycling the ILOCK if the
inode already has dquots attached. This makes the naming and locking
requirements consistent with the rest of the filesystem.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: disable online repair quota helpers when quota not enabled

Don't compile the quota helper functions if quota isn't being built into
the XFS module.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: repair inode btrees

Use the rmapbt to find inode chunks, query the chunks to compute hole
and free masks, and with that information rebuild the inobt and finobt.
Refer to the case study in
Documentation/filesystems/xfs-online-fsck-design.rst for more details.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: repair free space btrees

Rebuild the free space btrees from the gaps in the rmap btree. Refer to
the case study in Documentation/filesystems/xfs-online-fsck-design.rst
for more details.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: track usage statistics of online fsck

Track the usage, outcomes, and run times of the online fsck code, and
report these values via debugfs. The columns in the file are:

* scrubber name

* number of scrub invocations
* clean objects found
* corruptions found
* optimizations found
* cross referencing failures
* inconsistencies found during cross referencing
* incomplete scrubs
* warnings
* number of time scrub had to retry
* cumulative amount of time spent scrubbing (microseconds)

* number of repair inovcations
* successfully repaired objects
* cumuluative amount of time spent repairing (microseconds)

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: reap large AG metadata extents when possible

When we're freeing extents that have been set in a bitmap, break the
bitmap extent into multiple sub-extents organized by fate, and reap the
extents. This enables us to dispose of old resources more efficiently
than doing them block by block.

While we're at it, rename the reaping functions to make it clear that
they're reaping per-AG extents.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: move the post-repair block reaping code to a separate file

Reaping blocks after a repair is a complicated affair involving a lot of
rmap btree lookups and figuring out if we're going to unmap or free old
metadata blocks that might be crosslinked. Eventually, we will need to
be able to reap per-AG metadata blocks, bmbt blocks from inode forks,
garbage CoW staging extents, and (even later) blocks from btrees rooted
in inodes. This results in a lot of reaping code, so we might as well
split that off while it's easy.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: cull repair code that will never get used

These two functions date from the era when I thought that we could
rebuild btrees by creating an alternate root and adding records one by
one. In other words, they predate the btree bulk loader. They're not
necessary now, so remove them.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: remove the for_each_xbitmap_ helpers

Remove the for_each_xbitmap_ macros in favor of proper iterator
functions. We'll soon be switching this data structure over to an
interval tree implementation, which means that we can't allow callers to
modify the bitmap during iteration without telling us.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: scrub should use ECHRNG to signal that the drain is needed

In the previous patch, we added jump labels to the intent drain code so
that regular filesystem operations need not pay the price of checking
for someone (scrub) waiting on intents to drain from some part of the
filesystem when that someone isn't running.

However, I observed that xfs/285 now spends a lot more time pushing the
AIL from the inode btree scrubber than it used to. This is because the
inobt scrubber will try push the AIL to try to get logged inode cores
written to the filesystem when it sees a weird discrepancy between the
ondisk inode and the inobt records. This AIL push is triggered when the
setup function sees TRY_HARDER is set; and the requisite EDEADLOCK
return is initiated when the discrepancy is seen.

The solution to this performance slow down is to use a different result
code (ECHRNG) for scrub code to signal that it needs to wait for
deferred intent work items to drain out of some part of the filesystem.
When this happens, set a new scrub state flag (XCHK_NEED_DRAIN) so that
setup functions will activate the jump label.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: update copyright years for scrub/ files

Update the copyright years in the scrub/ source code files. This isn't
required, but it's helpful to remind myself just how long it's taken to
develop this feature.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: fix author and spdx headers on scrub/ files

Fix the spdx tags to match current practice, and update the author
contact information.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: pass per-ag references to xfs_free_extent

Pass a reference to the per-AG structure to xfs_free_extent. Most
callers already have one, so we can eliminate unnecessary lookups. The
one exception to this is the EFI code, which the next patch will fix.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: introduce xfs_alloc_vextent_exact_bno()

Two of the callers to xfs_alloc_vextent_this_ag() actually want
exact block number allocation, not anywhere-in-ag allocation. Split
this out from _this_ag() as a first class citizen so no external
extent allocation code needs to care about args->type anymore.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

xfs: use xfs_alloc_vextent_this_ag() where appropriate

Change obvious callers of single AG allocation to use
xfs_alloc_vextent_this_ag(). Drive the per-ag grabbing out to the
callers, too, so that callers with active references don't need
to do new lookups just for an allocation in a context that already
has a perag reference.

The only remaining caller that does single AG allocation through
xfs_alloc_vextent() is xfs_bmap_btalloc() with
XFS_ALLOCTYPE_NEAR_BNO. That is going to need more untangling before
it can be converted cleanly.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

xfs: perags need atomic operational state

We currently don't have any flags or operational state in the
xfs_perag except for the pagf_init and pagi_init flags. And the
agflreset flag. Oh, there's also the pagf_metadata and pagi_inodeok
flags, too.

For controlling per-ag operations, we are going to need some atomic
state flags. Hence add an opstate field similar to what we already
have in the mount and log, and convert all these state flags across
to atomic bit operations.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

xfs: don't return -EFSCORRUPTED from repair when resources cannot be grabbed

If we tried to repair something but the repair failed with -EDEADLOCK,
that means that the repair function couldn't grab some resource it
needed and wants us to try again. If we try again (with TRY_HARDER) but
still can't get all the resources we need, the repair fails and errors
remain on the filesystem.

Right now, repair returns the -EDEADLOCK to the caller as -EFSCORRUPTED,
which results in XFS_SCRUB_OFLAG_CORRUPT being passed out to userspace.
This is not correct because repair has not determined that anything is
corrupt. If the repair had been invoked on an object that could be
optimized but wasn't corrupt (OFLAG_PREEN), the inability to grab
resources will be reported to userspace as corrupt metadata, and users
will be unnecessarily alarmed that their suboptimal metadata turned into
a corruption.

Fix this by returning zero so that the results of the actual scrub will
be copied back out to userspace.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: don't retry repairs harder when EAGAIN is returned

Repair functions will not return EAGAIN -- if they were not able to
obtain resources, they should return EDEADLOCK (like the rest of online
fsck) to signal that we need to grab all the resources and try again.
Hence we don't need to deal with this case except as a debugging
assertion.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: log the AGI/AGF buffers when rolling transactions during an AG repair

Currently, the only way to lock an allocation group is to hold the AGI
and AGF buffers. If a repair needs to roll the transaction while
repairing some AG metadata, it maintains that lock by holding the two
buffers across the transaction roll and joins them afterwards.

However, repair is not like other parts of XFS that employ the bhold -
roll - bjoin sequence because it's possible that the AGI or AGF buffers
are not actually dirty before the roll. This presents two problems --
First, we need to redirty those buffers to keep them moving along in the
log to avoid pinning the log tail. Second, a clean buffer log item can
detach from the buffer. If this happens, the buffer type state is
discarded along with the bli and must be reattached before the next time
the buffer is logged. If it is not, the logging code will complain and
log recovery will not work properly.

An earlier version of this patch tried to fix the second problem by
re-setting the buffer type in the bli after joining the buffer to the
new transaction, but that looked weird and didn't solve the first
problem. Instead, solve both problems by logging the buffer before
rolling the transaction.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: don't track the AGFL buffer in the scrub AG context

While scrubbing an allocation group, we don't need to hold the AGFL
buffer as part of the scrub context. All that is necessary to lock an
AG is to hold the AGI and AGF buffers, so fix all the existing users of
the AGFL buffer to grab them only when necessary.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: fix for variable set but not used warning

Fix below kernel warning:

fs/xfs/scrub/repair.c:539:19: warning: variable 'agno' set but not used [-Wunused-but-set-variable]

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: sunliming <sunliming@kylinos.cn>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

xfs: rework xfs_buf_incore() API

Make it consistent with the other buffer APIs to return a error and
the buffer is placed in a parameter.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

xfs: replace xfs_ag_block_count() with perag accesses

Many of the places that call xfs_ag_block_count() have a perag
available. These places can just read pag->block_count directly
instead of calculating the AG block count from first principles.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

xfs: Pre-calculate per-AG agino geometry

There is a lot of overhead in functions like xfs_verify_agino() that
repeatedly calculate the geometry limits of an AG. These can be
pre-calculated as they are static and the verification context has
a per-ag context it can quickly reference.

In the case of xfs_verify_agino(), we now always have a perag
context handy, so we can store the minimum and maximum agino values
in the AG in the perag. This means we don't have to calculate
it on every call and it can be inlined in callers if we move it
to xfs_ag.h.

xfs_verify_agino_or_null() gets the same perag treatment.

xfs_agino_range() is moved to xfs_ag.c as it's not really a type
function, and it's use is largely restricted as the first and last
aginos can be grabbed straight from the perag in most cases.

Note that we leave the original xfs_verify_agino in place in
xfs_types.c as a static function as other callers in that file do
not have per-ag contexts so still need to go the long way. It's been
renamed to xfs_verify_agno_agino() to indicate it takes both an agno
and an agino to differentiate it from new function.

$ size --totals fs/xfs/built-in.a
text data bss dec hex filename
before 1482185 329588 572 1812345 1ba779 (TOTALS)
after 1481937 329588 572 1812097 1ba681 (TOTALS)

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

xfs: pass perag to xfs_alloc_put_freelist

It's available in all callers, so pass it in so that the perag can
be passed further down the stack.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

xfs: pass perag to xfs_alloc_get_freelist

It's available in all callers, so pass it in so that the perag can
be passed further down the stack.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

xfs: pass perag to xfs_alloc_read_agf()

xfs_alloc_read_agf() initialises the perag if it hasn't been done
yet, so it makes sense to pass it the perag rather than pull a
reference from the buffer. This allows callers to be per-ag centric
rather than passing mount/agno pairs everywhere.

Whilst modifying the xfs_reflink_find_shared() function definition,
declare it static and remove the extern declaration as it is an
internal function only these days.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

xfs: pass perag to xfs_ialloc_read_agi()

xfs_ialloc_read_agi() initialises the perag if it hasn't been done
yet, so it makes sense to pass it the perag rather than pull a
reference from the buffer. This allows callers to be per-ag centric
rather than passing mount/agno pairs everywhere.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

xfs: fix quotaoff mutex usage now that we don't support disabling it

Prior to commit 40b52225e58c ("xfs: remove support for disabling quota
accounting on a mounted file system"), we used the quotaoff mutex to
protect dquot operations against quotaoff trying to pull down dquots as
part of disabling quota.

Now that we only support turning off quota enforcement, the quotaoff
mutex only protects changes in m_qflags/sb_qflags. We don't need it to
protect dquots, which means we can remove it from setqlimits and the
dquot scrub code. While we're at it, fix the function that forces
quotacheck, since it should have been taking the quotaoff mutex.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: replace xfs_sb_version checks with feature flag checks

Convert the xfs_sb_version_hasfoo() to checks against
mp->m_features. Checks of the superblock itself during disk
operations (e.g. in the read/write verifiers and the to/from disk
formatters) are not converted - they operate purely on the
superblock state. Everything else should use the mount features.

Large parts of this conversion were done with sed with commands like
this:

for f in `git grep -l xfs_sb_version_has fs/xfs/*.c`; do
sed -i -e 's/xfs_sb_version_has\(.*\)(&\(.*\)->m_sb)/xfs_has_\1(\2)/' $f
done

With manual cleanups for things like "xfs_has_extflgbit" and other
little inconsistencies in naming.

The result is ia lot less typing to check features and an XFS binary
size reduced by a bit over 3kB:

$ size -t fs/xfs/built-in.a
text data bss dec hex filenam
before 1130866 311352 484 1442702 16038e (TOTALS)
after 1127727 311352 484 1439563 15f74b (TOTALS)

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

xfs: make the record pointer passed to query_range functions const

The query_range functions are supposed to call a caller-supplied
function on each record found in the dataset. These functions don't
own the memory storing the record, so don't let them change the record.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: remove unnecessary agno variable from struct xchk_ag

Now that we always grab an active reference to a perag structure when
dealing with perag metadata, we can remove this unnecessary variable.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: convert rmap btree cursor to using a perag

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

xfs: add a perag to the btree cursor

Which will eventually completely replace the agno in it.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: pass perags through to the busy extent code

All of the callers of the busy extent API either have perag
references available to use so we can pass a perag to the busy
extent functions rather than having them have to do unnecessary
lookups.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

xfs: move xfs_perag_get/put to xfs_ag.[ch]

They are AG functions, not superblock functions, so move them to the
appropriate location.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

xfs: Fix fall-through warnings for Clang

In preparation to enable -Wimplicit-fallthrough for Clang, fix
the following warnings by replacing /* fall through */ comments,
and its variants, with the new pseudo-keyword macro fallthrough:

fs/xfs/libxfs/xfs_alloc.c:3167:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_da_btree.c:286:3: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_ag_resv.c:346:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_ag_resv.c:388:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_bmap_util.c:246:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_export.c:88:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_export.c:96:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_file.c:867:3: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_ioctl.c:562:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_ioctl.c:1548:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_iomap.c:1040:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_inode.c:852:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_log.c:2627:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_trans_buf.c:298:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/bmap.c:275:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/btree.c:48:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/common.c:85:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/common.c:138:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/common.c:698:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/dabtree.c:51:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/repair.c:951:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/agheader.c:89:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]

Notice that Clang doesn't recognize /* fall through */ comments as
implicit fall-through markings, so in order to globally enable
-Wimplicit-fallthrough for Clang, these comments need to be
replaced with fallthrough; in the whole codebase.

Link: https://github.com/KSPP/linux/issues/115
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

xfs: get rid of the ip parameter to xchk_setup_*

Now that the scrub context stores a pointer to the file that was used to
invoke the scrub call, the struct xfs_inode pointer that we passed to
all the setup functions is no longer necessary. This is only ever used
if the caller wants us to scrub the metadata of the open file.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: fix uninitialized variables in xrep_calc_ag_resblks

If we can't read the AGF header, we never actually set a value for
freelen and usedlen. These two variables are used to make the worst
case estimate of btree size, so it's safe to set them to the AG size as
a fallback.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: create xfs_dqtype_t to represent quota types

Create a new type (xfs_dqtype_t) to represent the type of an incore
dquot (user, group, project, or none). Rename the incore dquot's
dq_flags field to q_type.

This allows us to replace all the "uint type" arguments to the quota
functions with "xfs_dqtype_t type", to make it obvious when we're
passing a quota type argument into a function.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: rename XFS_DQ_{USER,GROUP,PROJ} to XFS_DQTYPE_*

We're going to split up the incore dquot state flags from the ondisk
dquot flags (eventually renaming this "type") so start by renaming the
three flags and the bitmask that are going to participate in this.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: rename xfs_bitmap to xbitmap

Shorten the name of xfs_bitmap to xbitmap since the scrub bitmap has
nothing to do with the libxfs bitmap.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: xrep_reap_extents should not destroy the bitmap

Remove the xfs_bitmap_destroy call from the end of xrep_reap_extents
because this sort of violates our rule that the function initializing a
structure should destroy it.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: remove XFS_BUF_TO_AGF

Just dereference bp->b_addr directly and make the code a little
simpler and more clear.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

xfs: remove unnecessary null pointer checks from _read_agf callers

Drop the null buffer pointer checks in all code that calls
xfs_alloc_read_agf and doesn't pass XFS_ALLOC_FLAG_TRYLOCK because
they're no longer necessary.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: make xfs_trans_get_buf return an error code

Convert xfs_trans_get_buf() to return numeric error codes like most
everywhere else in xfs.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: remove all *_ITER_ABORT values

Use -ECANCELED to signal "stop iterating" instead of these magical
*_ITER_ABORT values, since it's duplicative.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: log proper length of btree block in scrub/repair

xfs_trans_log_buf() takes a final argument of the last byte to
log in the buffer; b_length is in basic blocks, so this isn't
the correct last byte. Fix it.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

xfs: create iterator error codes

Currently, xfs doesn't have generic error codes defined for "stop
iterating"; we just reuse the XFS_BTREE_QUERY_* return values. This
looks a little weird if we're not actually iterating a btree index.
Before we start adding more iterators, we should create general
XFS_ITER_{CONTINUE,ABORT} return values and define the XFS_BTREE_QUERY_*
ones from that.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: remove unused header files

There are many, many xfs header files which are included but
unneeded (or included twice) in the xfs code, so remove them.

nb: xfs_linux.h includes about 9 headers for everyone, so those
explicit includes get removed by this. I'm not sure what the
preference is, but if we wanted explicit includes everywhere,
a followup patch could remove those xfs_*.h includes from
xfs_linux.h and move them into the files that need them.
Or it could be left as-is.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

xfs: remove unused flag arguments

There are several functions which take a flag argument that is
only ever passed as "0," so remove these arguments.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

xfs: fix broken bhold behavior in xrep_roll_ag_trans

In xrep_roll_ag_trans, the transaction roll will always set sc->tp to
the new transaction, even if committing the old one fails. A bare
transaction roll leaves the buffer(s) locked but not joined to the new
transaction, so it's not necessary to release the hold if the roll
fails. Remove the incorrect xfs_trans_bhold_release calls.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: hoist the already_fixed variable to the scrub context

Now that we no longer memset the scrub context, we can move the
already_fixed variable into the scrub context's state flags instead of
passing around pointers to separate stack variables.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: collapse scrub bool state flags into a single unsigned int

Combine all the boolean state flags in struct xfs_scrub into a single
unsigned int, because we're going to be adding more state flags soon.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: use buf ops magic to detect btree block type

Now that we encode block magic numbers in all the buffer ops, use that
for block type detection in the ag header repair code instead of
encoding magics directly in the repair code.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: set buffer ops when repair probes for btree type

In xrep_findroot_block, we work out the btree type and correctness of a
given block by calling different btree verifiers on root block
candidates. However, we leave the NULL b_ops while ->verify_read
validates the block, which means that if the verifier calls
xfs_buf_verifier_error it'll crash on the null b_ops. Fix it to set
b_ops before calling the verifier and unsetting it if the verifier
fails.

Furthermore, improve the documentation around xfs_buf_ensure_ops, which
is the function that is responsible for cleaning up the b_ops state of
buffers that go through xrep_findroot_block but don't match anything.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: remove xfs_rmap_ag_owner and friends

Owner information for static fs metadata can be defined readonly at
build time because it never changes across filesystems. This enables us
to reduce stack usage (particularly in scrub) because we can use the
statically defined oinfo structures.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: const-ify xfs_owner_info arguments

Only certain functions actually change the contents of an
xfs_owner_info; the rest can accept a const struct pointer. This will
enable us to save stack space by hoisting static owner info types to
be const global variables.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: fix buffer state management in xrep_findroot_block

We don't handle buffer state properly in online repair's findroot
routine. If a buffer already has b_ops set, we don't ever want to touch
that, and we don't want to call the read verifiers on a buffer that
could be dirty (CRCs are only recomputed during log checkpoints).

Therefore, be more careful about what we do with a buffer -- if someone
else already attached ops that are not the ones for this btree type,
just ignore the buffer. We only attach our btree type's buf ops if it
matches the magic/uuid and structure checks.

We also modify xfs_buf_read_map to allow callers to set buffer ops on a
DONE buffer with NULL ops so that repair doesn't leave behind buffers
which won't have buffers attached to them.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

xfs: xrep_findroot_block should reject root blocks with siblings

In xrep_findroot_block, if we find a candidate root block with sibling
pointers or sibling blocks on the same tree level, we should not return
that block as a tree root because root blocks cannot have siblings.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

xfs: sanity check ag header values in xrep_calc_ag_resblks

Check the values we read in from the AG headers when calculating the
block reservations for a repair transaction. If they're obviously
wrong, substitute worst case assumptions (rather than ENOSPC on a bogus
reservation request).

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>

xfs: repair the AGF

Regenerate the AGF from the rmap data.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: refactor the xrep_extent_list into xfs_bitmap

As mentioned previously, the xrep_extent_list basically implements a
bitmap with two functions: set and disjoint union. Rename all these
functions to xfs_bitmap to shorten the name and make it more obvious
what we're doing.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: move the repair extent list into its own file

Move the xrep_extent_list code into a separate file. Logically, this
data structure is really just a clumsy bitmap, and in the next patch
we'll make this more obvious. No functional changes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: fix indentation and other whitespace problems in scrub/repair

Now that we've shortened everything, fix up all the indentation and
whitespace problems. There are no functional changes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: shorten struct xfs_scrub_context to struct xfs_scrub

Shorten the name of the online fsck context structure. Whitespace
damage will be fixed by a subsequent patch. There are no functional
changes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: shorten xfs_repair_ prefix to xrep_

Shorten all the metadata repair xfs_repair_* symbols to xrep_.
Whitespace damage will be fixed by a subsequent patch. There are no
functional changes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: shorten xfs_scrub_ prefix

Shorten all the metadata checking xfs_scrub_ prefixes to xchk_. After
this, the only xfs_scrub* symbols are the ones that pertain to both
scrub and repair. Whitespace damage will be fixed in a subsequent
patch. There are no functional changes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: clean up xfs_btree_del_cursor callers

Less trivial cleanups of the error argument to xfs_btree_del_cursor;
these require some minor code refactoring.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: trivial xfs_btree_del_cursor cleanups

The error argument to xfs_btree_del_cursor already understands the
"nonzero for error" semantics, so remove pointless error testing in the
callers and pass it directly.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: convert to SPDX license tags

Remove the verbose license text from XFS files and replace them
with SPDX tags. This does not change the license of any of the code,
merely refers to the common, up-to-date license files in LICENSES/

This change was mostly scripted. fs/xfs/Makefile and
fs/xfs/libxfs/xfs_fs.h were modified by hand, the rest were detected
and modified by the following command:

for f in `git grep -l "GNU General" fs/xfs/` ; do
echo $f
cat $f | awk -f hdr.awk > $f.new
mv -f $f.new $f
done

And the hdr.awk script that did the modification (including
detecting the difference between GPL-2.0 and GPL-2.0+ licenses)
is as follows:

$ cat hdr.awk
BEGIN {
hdr = 1.0
tag = "GPL-2.0"
str = ""
}

/^ \* This program is free software/ {
hdr = 2.0;
next
}

/any later version./ {
tag = "GPL-2.0+"
next
}

/^ \*\// {
if (hdr > 0.0) {
print "// SPDX-License-Identifier: " tag
print str
print $0
str=""
hdr = 0.0
next
}
print $0
next
}

/^ \* / {
if (hdr > 1.0)
next
if (hdr > 0.0) {
if (str != "")
str = str "\n"
str = str $0
next
}
print $0
next
}

/^ \*/ {
if (hdr > 0.0)
next
print $0
next
}

// {
if (hdr > 0.0) {
if (str != "")
str = str "\n"
str = str $0
next
}
print $0
}

END { }
$

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

xfs: add helpers to attach quotas to inodes

Add a helper routine to attach quota information to inodes that are
about to undergo repair. If that fails, we need to schedule a
quotacheck for the next mount but allow the corrupted metadata repair to
continue.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: recover AG btree roots from rmap data

Add a helper function to help us recover btree roots from the rmap data.
Callers pass in a list of rmap owner codes, buffer ops, and magic
numbers. We iterate the rmap records looking for owner matches, and
then read the matching blocks to see if the magic number & uuid match.
If so, we then read-verify the block, and if that passes then we retain
a pointer to the block with the highest level, assuming that by the end
of the call we will have found the root. This will be used to reset the
AGF/AGI btree root fields during their rebuild procedures.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: add helpers to dispose of old btree blocks after a repair

Now that we've plumbed in the ability to construct a list of dead btree
blocks following a repair, add more helpers to dispose of them. This is
done by examining the rmapbt -- if the btree was the only owner we can
free the block, otherwise it's crosslinked and we can only remove the
rmapbt record.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: add helpers to collect and sift btree block pointers during repair

Add some helpers to assemble a list of fs block extents. Generally,
repair functions will iterate the rmapbt to make a list (1) of all
extents owned by the nominal owner of the metadata structure; then they
will iterate all other structures with the same rmap owner to make a
list (2) of active blocks; and finally we have a subtraction function to
subtract all the blocks in (2) from (1), with the result that (1) is now
a list of blocks that were owned by the old btree and must be disposed.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: add helpers to allocate and initialize fresh btree roots

Add a pair of helper functions to allocate and initialize fresh btree
roots. The repair functions will use these as part of recreating
corrupted metadata.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>

xfs: add helpers to deal with transaction allocation and rolling

For repairs, we need to reserve at least as many blocks as we think
we're going to need to rebuild the data structure, and we're going to
need some helpers to roll transactions while maintaining locks on the AG
headers so that other threads cannot wander into the middle of a repair.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>

xfs: implement the metadata repair ioctl flag

Plumb in the pieces necessary to make the "scrub" subfunction of
the scrub ioctl actually work. This means that we make the IFLAG_REPAIR
flag to the scrub ioctl actually do something, and we add an errortag
knob so that xfstests can force the kernel to rebuild a metadata
structure even if there's nothing wrong with it.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>