xfs: support in-memory btrees

Adapt the generic btree cursor code to be able to create a btree whose
buffers come from a (presumably in-memory) buftarg with a header block
that's specific to in-memory btrees. We'll connect this to other parts
of online scrub in the next patches.

Note that in-memory btrees always have a block size matching the system
memory page size for efficiency reasons. There are also a few things we
need to do to finalize a btree update; that's covered in the next patch.

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

xfs: move and rename xfs_btree_read_bufl

Despite its name, xfs_btree_read_bufl doesn't contain any btree-related
functionaliy and isn't used by the btree code. Move it to xfs_bmap.c,
hard code the refval and ops arguments and rename it to
xfs_bmap_read_buf.

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: remove xfs_btree_reada_bufs

xfs_btree_reada_bufl just wraps xfs_btree_readahead and a agblock
to daddr conversion. Just open code it's three callsites in the
two callers (One of which isn't even btree related).

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: remove xfs_btree_reada_bufl

xfs_btree_reada_bufl just wraps xfs_btree_readahead and a fsblock
to daddr conversion. Just open code it's two callsites in the only
caller.

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: rename btree helpers that depends on the block number representation

All these helpers hardcode fsblocks or agblocks and not just the pointer
size. Rename them so that the names are still fitting when we add the
long format in-memory blocks and adjust the checks when calling them to
check the btree types and not just pointer length.

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: consolidate btree block verification

Add a __xfs_btree_check_block helper that can be called by the scrub code
to validate a btree block of any form, and move the duplicate error
handling code from xfs_btree_check_sblock and xfs_btree_check_lblock into
xfs_btree_check_block and thus remove these two helpers.

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: consolidate btree ptr checking

Merge xfs_btree_check_sptr and xfs_btree_check_lptr into a single
__xfs_btree_check_ptr that can be shared between xfs_btree_check_ptr
and the scrub code.

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: remove xfs_btnum_t

The last checks for bc_btnum can be replaced with helpers that check
the btree ops. This allows adding new btrees to XFS without having
to update a global enum.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
[djwong: complete the ops predicates]
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

xfs: add a sick_mask to struct xfs_btree_ops

Clean up xfs_btree_mark_sick by adding a sick_mask to the btree-ops
for all AG-root btrees.

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: add a name field to struct xfs_btree_ops

The btnum in struct xfs_btree_ops is often used for printing a symbolic
name for the btree. Add a name field to the ops structure and use that
directly.

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: add a xfs_btree_init_ptr_from_cur

Inode-rooted btrees don't need to initialize the root pointer in the
->init_ptr_from_cur method as the root is found by the
xfs_btree_get_iroot method later. Make ->init_ptr_from_cur option
for inode rooted btrees by providing a helper that does the right
thing for the given btree type and also documents the semantics.

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: create predicate to determine if cursor is at inode root level

Create a predicate to decide if the given cursor and level point to the
root block in the inode immediate area instead of a disk block, and get
rid of the open-coded logic everywhere.

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

xfs: split the per-btree union in struct xfs_btree_cur

Split up the union that encodes btree-specific fields in struct
xfs_btree_cur. Most fields in there are specific to the btree type
encoded in xfs_btree_ops.type, and we can use the obviously named union
for that. But one field is specific to the bmapbt and two are shared by
the refcount and rtrefcountbt. Move those to a separate union to make
the usage clear and not need a separate struct for the refcount-related
fields.

This will also make unnecessary some very awkward btree cursor
refc/rtrefc switching logic in the rtrefcount patchset.

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 out a btree type from the btree ops geometry flags

Two of the btree cursor flags are always used together and encode
the fundamental btree type. There currently are two such types:

1) an on-disk AG-rooted btree with 32-bit pointers
2) an on-disk inode-rooted btree with 64-bit pointers

and we're about to add:

3) an in-memory btree with 64-bit pointers

Introduce a new enum and a new type field in struct xfs_btree_geom
to encode this type directly instead of using flags and change most
code to switch on this enum.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
[djwong: make the pointer lengths explicit]
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

xfs: store the btree pointer length in struct xfs_btree_ops

Make the pointer length an explicit field in the btree operations
structure so that the next patch (which introduces an explicit btree
type enum) doesn't have to play a bunch of awkward games with inferring
the pointer length from the enumeration.

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

xfs: move the btree stats offset into struct btree_ops

The statistics offset is completely static, move it into the btree_ops
structure instead of the cursor.

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: move lru refs to the btree ops structure

Move the btree buffer LRU refcount to the btree ops structure so that we
can eliminate the last bc_btnum switch in the generic btree code. We're
about to create repair-specific btree types, and we don't want that
stuff cluttering up libxfs.

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

xfs: remove the unnecessary daddr paramter to _init_block

Now that all of the callers pass XFS_BUF_DADDR_NULL as the daddr
parameter, we can elide that too.

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

xfs: rename btree block/buffer init functions

Rename xfs_btree_init_block_int to xfs_btree_init_block, and
xfs_btree_init_block to xfs_btree_init_buf so that the name suggests the
type that caller are supposed to pass in.

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

xfs: initialize btree blocks using btree_ops structure

Notice now that the btree ops structure encodes btree geometry flags and
the magic number through the buffer ops. Refactor the btree block
initialization functions to use the btree ops so that we no longer have
to open code all that.

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

xfs: turn the allocbt cursor active field into a btree flag

Add a new XFS_BTREE_ALLOCBT_ACTIVE flag to replace the active field.

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: remove bc_ino.flags

Just move the two flags into bc_flags where there is plenty of space.

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: encode the btree geometry flags in the btree ops structure

Certain btree flags never change for the life of a btree cursor because
they describe the geometry of the btree itself. Encode these in the
btree ops structure and reduce the amount of code required in each btree
type's init_cursor functions. This also frees up most of the bits in
bc_flags.

A previous version of this patch also converted the open-coded flags
logic to helpers. This was removed due to the pending refactoring (that
follows this patch) to eliminate most of the state flags.

Conversion script:

sed \
-e 's/XFS_BTREE_LONG_PTRS/XFS_BTGEO_LONG_PTRS/g' \
-e 's/XFS_BTREE_ROOT_IN_INODE/XFS_BTGEO_ROOT_IN_INODE/g' \
-e 's/XFS_BTREE_LASTREC_UPDATE/XFS_BTGEO_LASTREC_UPDATE/g' \
-e 's/XFS_BTREE_OVERLAPPING/XFS_BTGEO_OVERLAPPING/g' \
-e 's/cur->bc_flags & XFS_BTGEO_/cur->bc_ops->geom_flags \& XFS_BTGEO_/g' \
-i $(git ls-files fs/xfs/*.[ch] fs/xfs/libxfs/*.[ch] fs/xfs/scrub/*.[ch])

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

xfs: drop XFS_BTREE_CRC_BLOCKS

All existing btree types set XFS_BTREE_CRC_BLOCKS when running against a
V5 filesystem. All currently proposed btree types are V5 only and use
the richer XFS_BTREE_CRC_BLOCKS format. Therefore, we can drop this
flag and change the conditional to xfs_has_crc.

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

xfs: set the btree cursor bc_ops in xfs_btree_alloc_cursor

This is a precursor to putting more static data in the btree ops structure.

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

xfs: use __GFP_NOLOCKDEP instead of GFP_NOFS

In the past we've had problems with lockdep false positives stemming
from inode locking occurring in memory reclaim contexts (e.g. from
superblock shrinkers). Lockdep doesn't know that inodes access from
above memory reclaim cannot be accessed from below memory reclaim
(and vice versa) but there has never been a good solution to solving
this problem with lockdep annotations.

This situation isn't unique to inode locks - buffers are also locked
above and below memory reclaim, and we have to maintain lock
ordering for them - and against inodes - appropriately. IOWs, the
same code paths and locks are taken both above and below memory
reclaim and so we always need to make sure the lock orders are
consistent. We are spared the lockdep problems this might cause
by the fact that semaphores and bit locks aren't covered by lockdep.

In general, this sort of lockdep false positive detection is cause
by code that runs GFP_KERNEL memory allocation with an actively
referenced inode locked. When it is run from a transaction, memory
allocation is automatically GFP_NOFS, so we don't have reclaim
recursion issues. So in the places where we do memory allocation
with inodes locked outside of a transaction, we have explicitly set
them to use GFP_NOFS allocations to prevent lockdep false positives
from being reported if the allocation dips into direct memory
reclaim.

More recently, __GFP_NOLOCKDEP was added to the memory allocation
flags to tell lockdep not to track that particular allocation for
the purposes of reclaim recursion detection. This is a much better
way of preventing false positives - it allows us to use GFP_KERNEL
context outside of transactions, and allows direct memory reclaim to
proceed normally without throwing out false positive deadlock
warnings.

The obvious places that lock inodes and do memory allocation are the
lookup paths and inode extent list initialisation. These occur in
non-transactional GFP_KERNEL contexts, and so can run direct reclaim
and lock inodes.

This patch makes a first path through all the explicit GFP_NOFS
allocations in XFS and converts the obvious ones to GFP_KERNEL |
__GFP_NOLOCKDEP as a first step towards removing explicit GFP_NOFS
allocations from the XFS code.

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

xfs: repair refcount btrees

Reconstruct the refcount data from the rmap btree.

Link: https://docs.kernel.org/filesystems/xfs-online-fsck-design.html#case-study-rebuilding-the-space-reference-counts
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: read leaf blocks when computing keys for bulkloading into node blocks

When constructing a new btree, xfs_btree_bload_node needs to read the
btree blocks for level N to compute the keyptrs for the blocks that will
be loaded into level N+1. The level N blocks must be formatted at that
point.

A subsequent patch will change the btree bulkloader to write new btree
blocks in 256K chunks to moderate memory consumption if the new btree is
very large. As a consequence of that, it's possible that the buffers
for lower level blocks might have been reclaimed by the time the node
builder comes back to the block.

Therefore, change xfs_btree_bload_node to read the lower level blocks
to handle the reclaimed buffer case. As a side effect, the read will
increase the LRU refs, which will bias towards keeping new btree buffers
in memory after the new btree commits.

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

overflow: Add struct_size_t() helper

While struct_size() is normally used in situations where the structure
type already has a pointer instance, there are places where no variable
is available. In the past, this has been worked around by using a typed
NULL first argument, but this is a bit ugly. Add a helper to do this,
and replace the handful of instances of the code pattern with it.

Instances were found with this Coccinelle script:

@struct_size_t@
identifier STRUCT, MEMBER;
expression COUNT;
@@

- struct_size((struct STRUCT *)\(0\|NULL\),
+ struct_size_t(struct STRUCT,
MEMBER, COUNT)

Suggested-by: Christoph Hellwig <hch@infradead.org>
Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
Cc: Tony Nguyen <anthony.l.nguyen@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: James Smart <james.smart@broadcom.com>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: HighPoint Linux Team <linux@highpoint-tech.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumit Saxena <sumit.saxena@broadcom.com>
Cc: Shivasharan S <shivasharan.srikanteshwara@broadcom.com>
Cc: Don Brace <don.brace@microchip.com>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Guo Xuenan <guoxuenan@huawei.com>
Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Daniel Latypov <dlatypov@google.com>
Cc: kernel test robot <lkp@intel.com>
Cc: intel-wired-lan@lists.osuosl.org
Cc: netdev@vger.kernel.org
Cc: linux-nvme@lists.infradead.org
Cc: linux-scsi@vger.kernel.org
Cc: megaraidlinux.pdl@broadcom.com
Cc: storagedev@microchip.com
Cc: linux-xfs@vger.kernel.org
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://lore.kernel.org/r/20230522211810.never.421-kees@kernel.org

xfs: implement masked btree key comparisons for _has_records scans

For keyspace fullness scans, we want to be able to mask off the parts of
the key that we don't care about. For most btree types we /do/ want the
full keyspace, but for checking that a given space usage also has a full
complement of rmapbt records (even if different/multiple owners) we need
this masking so that we only track sparseness of rm_startblock, not the
whole keyspace (which is extremely sparse).

Augment the ->diff_two_keys and ->keys_contiguous helpers to take a
third union xfs_btree_key argument, and wire up xfs_rmap_has_records to
pass this through. This third "mask" argument should contain a nonzero
value in each structure field that should be used in the key comparisons
done during the scan.

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

xfs: replace xfs_btree_has_record with a general keyspace scanner

The current implementation of xfs_btree_has_record returns true if it
finds /any/ record within the given range. Unfortunately, that's not
sufficient for scrub. We want to be able to tell if a range of keyspace
for a btree is devoid of records, is totally mapped to records, or is
somewhere in between. By forcing this to be a boolean, we conflated
sparseness and fullness, which caused scrub to return incorrect results.
Fix the API so that we can tell the caller which of those three is the
current state.

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

xfs: refactor ->diff_two_keys callsites

Create wrapper functions around ->diff_two_keys so that we don't have to
remember what the return values mean, and adjust some of the code
comments to reflect the longtime code behavior. We're going to
introduce more uses of ->diff_two_keys in the next patch, so reduce the
cognitive load for readers by doing this refactoring now.

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

xfs: get rid of assert from xfs_btree_islastblock

xfs_btree_check_block contains debugging knobs. With XFS_DEBUG setting up,
turn on the debugging knob can trigger the assert of xfs_btree_islastblock,
test script as follows:

while true
do
mount $disk $mountpoint
fsstress -d $testdir -l 0 -n 10000 -p 4 >/dev/null
echo 1 > /sys/fs/xfs/sda/errortag/btree_chk_sblk
sleep 10
umount $mountpoint
done

Kick off fsstress and only *then* turn on the debugging knob. If it
happens that the knob gets turned on after the cntbt lookup succeeds
but before the call to xfs_btree_islastblock, then we *can* end up in
the situation where a previously checked btree block suddenly starts
returning EFSCORRUPTED from xfs_btree_check_block. Kaboom.

Darrick give a very detailed explanation as follows:
Looking back at commit 27d9ee577dcce, I think the point of all this was
to make sure that the cursor has actually performed a lookup, and that
the btree block at whatever level we're asking about is ok.

If the caller hasn't ever done a lookup, the bc_levels array will be
empty, so cur->bc_levels[level].bp pointer will be NULL. The call to
xfs_btree_get_block will crash anyway, so the "ASSERT(block);" part is
pointless.

If the caller did a lookup but the lookup failed due to block
corruption, the corresponding cur->bc_levels[level].bp pointer will also
be NULL, and we'll still crash. The "ASSERT(xfs_btree_check_block);"
logic is also unnecessary.

If the cursor level points to an inode root, the block buffer will be
incore, so it had better always be consistent.

If the caller ignores a failed lookup after a successful one and calls
this function, the cursor state is garbage and the assert wouldn't have
tripped anyway. So get rid of the assert.

Fixes: 27d9ee577dcc ("xfs: actually check xfs_btree_check_block return in xfs_btree_islastblock")
Signed-off-by: Guo Xuenan <guoxuenan@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

xfs: convert btree buffer log flags to unsigned.

5.18 w/ std=gnu11 compiled with gcc-5 wants flags stored in unsigned
fields to be unsigned.

We also pass the fields to log to xfs_btree_offsets() as a uint32_t
all cases now. I have no idea why we made that parameter a int64_t
in the first place, but while we are fixing this up change it to
a uint32_t field, too.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

xfs: remove kmem_zone typedef

Remove these typedefs by referencing kmem_cache directly.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>

xfs: use separate btree cursor cache for each btree type

Now that we have the infrastructure to track the max possible height of
each btree type, we can create a separate slab cache for cursors of each
type of btree. For smaller indices like the free space btrees, this
means that we can pack more cursors into a slab page, improving slab
utilization.

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

xfs: kill XFS_BTREE_MAXLEVELS

Nobody uses this symbol anymore, so kill it.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: compute the maximum height of the rmap btree when reflink enabled

Instead of assuming that the hardcoded XFS_BTREE_MAXLEVELS value is big
enough to handle the maximally tall rmap btree when all blocks are in
use and maximally shared, let's compute the maximum height assuming the
rmapbt consumes as many blocks as possible.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

xfs: clean up xfs_btree_{calc_size,compute_maxlevels}

During review of the next patch, Dave remarked that he found these two
btree geometry calculation functions lacking in documentation and that
they performed more work than was really necessary.

These functions take the same parameters and have nearly the same logic;
the only real difference is in the return values. Reword the function
comment to make it clearer what each function does, and move them to be
adjacent to reinforce their relation.

Clean up both of them to stop opencoding the howmany functions, stop
using the uint typedefs, and make them both support computations for
more than 2^32 leaf records, since we're going to need all of the above
for files with large data forks and large rmap btrees.

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

xfs: dynamically allocate cursors based on maxlevels

To support future btree code, we need to be able to size btree cursors
dynamically for very large btrees. Switch the maxlevels computation to
use the precomputed values in the superblock, and create cursors that
can handle a certain height. For now, we retain the btree cursor cache
that can handle up to 9-level btrees, though a subsequent patch
introduces separate caches for each btree type, where each cache's
objects will be exactly tall enough to handle the specific btree type.

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

xfs: encode the max btree height in the cursor

Encode the maximum btree height in the cursor, since we're soon going to
allow smaller cursors for AG btrees and larger cursors for file btrees.

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

xfs: refactor btree cursor allocation function

Refactor btree allocation to a common helper.

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

xfs: rearrange xfs_btree_cur fields for better packing

Reduce the size of the btree cursor structure some more by rearranging
fields to eliminate unused space. While we're at it, fix the ragged
indentation and a spelling error.

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

xfs: prepare xfs_btree_cur for dynamic cursor heights

Split out the btree level information into a separate struct and put it
at the end of the cursor structure as a VLA. Files with huge data forks
(and in the future, the realtime rmap btree) will require the ability to
support many more levels than a per-AG btree cursor, which means that
we're going to create per-btree type cursor caches to conserve memory
for the more common case.

Note that a subsequent patch actually introduces dynamic cursor heights.
This one merely rearranges the structure to prepare for that.

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

xfs: reduce the size of nr_ops for refcount btree cursors

We're never going to run more than 4 billion btree operations on a
refcount cursor, so shrink the field to an unsigned int to reduce the
structure size. Fix whitespace alignment too.

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

xfs: remove xfs_btree_cur.bc_blocklog

This field isn't used by anyone, so get rid of it.

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

xfs: remove xfs_btree_cur_t typedef

Get rid of this old typedef before we start changing other things.

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

xfs: constify btree function parameters that are not modified

Constify the rest of the btree functions that take structure and union
pointers and are not supposed to modify them.

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

xfs: make the start pointer passed to btree update_lastrec functions const

This btree function is called when updating a record in the rightmost
block of a btree so that we can update the AGF's longest free extent
length field. Neither parameter is supposed to be updated, so mark them
both const.

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

xfs: make the start pointer passed to btree alloc_block functions const

The @start pointer passed to each per-AG btree type's ->alloc_block
function isn't supposed to be modified, since it's a hint about the
location of the btree block being split that is to be fed to the
allocator, so mark the parameter const.

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

xfs: make the pointer passed to btree set_root functions const

The pointer passed to each per-AG btree type's ->set_root function isn't
supposed to be modified (that function sets an external pointer to the
root block) so mark them const.

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

xfs: make the keys and records passed to btree inorder functions const

The inorder functions are simple predicates, which means that they don't
modify the parameters. Mark them all const.

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

xfs: mark the record passed into btree init_key functions as const

These functions initialize a key from a record, but they aren't supposed
to modify the record. Mark it const.

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

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: make the key parameters to all btree query range functions const

Range query functions are not supposed to modify the query keys that are
being passed in, so mark them all const.

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

xfs: make the key parameters to all btree key comparison functions const

The btree key comparison functions are not allowed to change the keys
that are passed in, so mark them const. We'll need this for the next
patch, which adds const to the btree range query functions.

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

xfs: remove agno from btree cursor

Now that everything passes a perag, the agno is not needed anymore.
Convert all the users to use pag->pag_agno instead and remove the
agno from the cursor. This was largely done as an automated search
and replace.

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: Use the correct style for SPDX License Identifier

This patch corrects the SPDX License Identifier style in header files
related to XFS File System support. For C header files
Documentation/process/license-rules.rst mandates C-like comments.
(opposed to C source files where C++ style should be used).

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

xfs: support bulk loading of staged btrees

Add a new btree function that enables us to bulk load a btree cursor.
This will be used by the upcoming online repair patches to generate new
btrees. This avoids the programmatic inefficiency of calling
xfs_btree_insert in a loop (which generates a lot of log traffic) in
favor of stamping out new btree blocks with ordered buffers, and then
committing both the new root and scheduling the removal of the old btree
blocks in a single transaction commit.

The design of this new generic code is based off the btree rebuilding
code in xfs_repair's phase 5 code, with the explicit goal of enabling us
to share that code between scrub and repair. It has the additional
feature of being able to control btree block loading factors.

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

xfs: introduce fake roots for inode-rooted btrees

Create an in-core fake root for inode-rooted btree types so that callers
can generate a whole new btree using the upcoming btree bulk load
function without making the new tree accessible from the rest of the
filesystem. It is up to the individual btree type to provide a function
to create a staged cursor (presumably with the appropriate callouts to
update the fakeroot) and then commit the staged root back into the
filesystem.

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

xfs: introduce fake roots for ag-rooted btrees

Create an in-core fake root for AG-rooted btree types so that callers
can generate a whole new btree using the upcoming btree bulk load
function without making the new tree accessible from the rest of the
filesystem. It is up to the individual btree type to provide a function
to create a staged cursor (presumably with the appropriate callouts to
update the fakeroot) and then commit the staged root back into the
filesystem.

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

xfs: make the btree ag cursor private union anonymous

This is much less widely used than the bc_private union was, so this
is done as a single patch. The named union xfs_btree_cur_private
goes away and is embedded into the struct xfs_btree_cur_ag as an
anonymous union, and the code is modified via this script:

$ sed -i 's/priv\.\([abt|refc]\)/\1/g' fs/xfs/*[ch] fs/xfs/*/*[ch]

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>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: make the btree cursor union members named structure

we need to name the btree cursor private structures to be able
to pull them out of the deeply nested structure definition they are
in now.

Based on code extracted from a patchset by Darrick Wong.

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>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: make btree cursor private union anonymous

Rename the union and it's internal structures to the new name and
remove the temporary defines that facilitated the change.

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>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: rename btree cursor private btree member flags

BPRV is not longer appropriate because bc_private is going away.
Script:

$ sed -i 's/BTCUR_BPRV/BTCUR_BMBT/g' fs/xfs/*[ch] fs/xfs/*/*[ch]

With manual cleanup to the definitions in fs/xfs/libxfs/xfs_btree.h

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
[darrick: change "BC_BT" to "BTCUR_BMBT", fix subject line typo]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: introduce new private btree cursor names

Just the defines of the new names - the conversion will be in
scripted commits after this.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
[darrick: change "bc_bt" to "bc_ino"]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

xfs: remove the xfs_btree_get_buf[ls] functions

Remove the xfs_btree_get_bufs and xfs_btree_get_bufl functions, since
they're pretty trivial oneliners.

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: actually check xfs_btree_check_block return in xfs_btree_islastblock

Coverity points out that xfs_btree_islastblock doesn't check the return
value of xfs_btree_check_block. Since the question "Does the cursor
point to the last block in this level?" only makes sense if the caller
previously performed a lookup or seek operation, the block should
already have been checked.

Therefore, check the return value in an ASSERT and turn the whole thing
into a static inline predicate.

Coverity-id: 114069
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

xfs: refactor xfs_iread_extents to use xfs_btree_visit_blocks

xfs_iread_extents open-codes everything in xfs_btree_visit_blocks, so
refactor the btree helper to be able to iterate only the records on
level 0, then port iread_extents to use it.

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

xfs: track active state of allocation btree cursors

The upcoming allocation algorithm update searches multiple
allocation btree cursors concurrently. As such, it requires an
active state to track when a particular cursor should continue
searching. While active state will be modified based on higher level
logic, we can define base functionality based on the result of
allocation btree lookups.

Define an active flag in the private area of the btree cursor.
Update it based on the result of lookups in the existing allocation
btree helpers. Finally, provide a new helper to query the current
state.

Signed-off-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 all *_ITER_CONTINUE values

Iterator functions already use 0 to signal "continue iterating", so get
rid of the #defines and just do it directly.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
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: 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 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: fold dfops into the transaction

struct xfs_defer_ops has now been reduced to a single list_head. The
external dfops mechanism is unused and thus everywhere a (permanent)
transaction is accessible the associated dfops structure is as well.

Remove the xfs_defer_ops structure and fold the list_head into the
transaction. Also remove the last remnant of external dfops in
xfs_trans_dup().

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

xfs: remove xfs_btree_cur private firstblock field

The bmbt cursor private structure has a firstblock field that is
used to maintain locking order on bmbt allocations. The field holds
an actual firstblock value (as opposed to a pointer), so it is
initialized on cursor creation, updated on allocation and then the
value is transferred back to the source before the cursor is
destroyed.

This value is always transferred from and back to the ->t_firstblock
field. Since xfs_btree_cur already carries a reference to the
transaction, we can remove this field from xfs_btree_cur and the
associated copying. The bmbt allocations will update the value in
the transaction directly.

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

xfs: remove unused btree cursor bc_private.a.dfops field

The xfs_btree_cur.bc_private.a.dfops field is only ever initialized
by the refcountbt cursor init function. The only caller of that
function with a non-NULL dfops is from deferred completion context,
which already has attached to ->t_dfops.

In addition to that, the only actual reference of a.dfops is the
cursor duplication function, which means the field is effectively
unused.

Remove the dfops field from the bc_private.a union. Any future users
can acquire the dfops from the transaction. This patch does not
change behavior.

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

xfs: remove xfs_btree_cur bmbt dfops field

All assignments of xfs_btree_cur.bc_private.b.dfops originate from
->t_dfops. Replace accesses of the former with the latter and remove
the unnecessary field. This patch does not change behavior.

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

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 repair helpers for the reference count btree

Add a couple of functions to the refcount btree and generic btree code
that will be used to repair the refcountbt.

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

xfs: add helpers to calculate btree size

Add a bunch of helper functions that calculate the sizes of various
btrees. These will be used to repair btrees and btree headers.

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

xfs: non-scrub - remove unused function parameters

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>

Cleanup old XFS_BTREE_* traces

Remove unused legacy btree traces from IRIX era.

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

xfs: add scrub cross-referencing helpers for the free space btrees

Add a couple of functions to the free space btrees that will be used
to cross-reference metadata against the bnobt/cntbt, and a generic
btree function that provides the real implementation.

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

xfs: have buffer verifier functions report failing address

Modify each function that checks the contents of a metadata buffer to
return the instruction address of the failing test so that we can report
more precise failure errors to the log.

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

xfs: refactor long-format btree header verification routines

Create two helper functions to verify the headers of a long format
btree block. We'll use this later for the realtime rmapbt.

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

xfs: remove XFS_FSB_SANITY_CHECK

We already have a function to verify fsb pointers, so get rid of the
last users of the (less robust) macro.

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

xfs: compare btree block keys to parent block's keys during scrub

When we're done checking all the records/keys in a btree block, compute
the low and high key of the block and compare them to the associated key
in the parent btree block.

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

xfs: scrub the shape of a metadata btree

Create a function that can check the shape of a btree -- each block
passes basic inspection and all the pointers look ok. In the next patch
we'll add the ability to check the actual keys and records stored within
the btree. Add some helper functions so that we report detailed scrub
errors in a uniform manner in dmesg. These are helper functions for
subsequent patches.

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

xfs: refactor btree block header checking functions

Refactor the btree block header checks to have an internal function that
returns the address of the failing check without logging errors. The
scrubber will call the internal function, while the external version
will maintain the current logging behavior.

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

xfs: refactor btree pointer checks

Refactor the btree pointer checks so that we can call them from the
scrub code without logging errors to dmesg. Preserve the existing error
reporting for regular operations.

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

xfs: skip bmbt block ino validation during owner change

Extent swap uses xfs_btree_visit_blocks() to fix up bmbt block
owners on v5 (!rmapbt) filesystems. The bmbt scan uses
xfs_btree_lookup_get_block() to read bmbt blocks which verifies the
current owner of the block against the parent inode of the bmbt.
This works during extent swap because the bmbt owners are updated to
the opposite inode number before the inode extent forks are swapped.

The modified bmbt blocks are marked as ordered buffers which allows
everything to commit in a single transaction. If the transaction
commits to the log and the system crashes such that recovery of the
extent swap is required, log recovery restarts the bmbt scan to fix
up any bmbt blocks that may have not been written back before the
crash. The log recovery bmbt scan occurs after the inode forks have
been swapped, however. This causes the bmbt block owner verification
to fail, leads to log recovery failure and requires xfs_repair to
zap the log to recover.

Define a new invalid inode owner flag to inform the btree block
lookup mechanism that the current inode may be invalid with respect
to the current owner of the bmbt block. Set this flag on the cursor
used for change owner scans to allow this operation to work at
runtime and during log recovery.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Fixes: bb3be7e7c ("xfs: check for bogus values in btree block headers")
Cc: stable@vger.kernel.org
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

xfs: export various function for the online scrubber

Export various internal functions so that the online scrubber can use
them to check the state of metadata.

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

xfs: always compile the btree inorder check functions

The btree record and key inorder check functions will be used by the
btree scrubber code, so make sure they're always built.

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

xfs: remove double-underscore integer types

This is a purely mechanical patch that removes the private
__{u,}int{8,16,32,64}_t typedefs in favor of using the system
{u,}int{8,16,32,64}_t typedefs. This is the sed script used to perform
the transformation and fix the resulting whitespace and indentation
errors:

s/typedef\t__uint8_t/typedef __uint8_t\t/g
s/typedef\t__uint/typedef __uint/g
s/typedef\t__int\([0-9]*\)_t/typedef int\1_t\t/g
s/__uint8_t\t/__uint8_t\t\t/g
s/__uint/uint/g
s/__int\([0-9]*\)_t\t/__int\1_t\t\t/g
s/__int/int/g
/^typedef.*int[0-9]*_t;$/d

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

xfs: create a function to query all records in a btree

Create a helper function that will query all records in a btree.
This will be used by the online repair functions to examine every
record in a btree to rebuild a second btree.

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

xfs: filter out obviously bad btree pointers

Don't let anybody load an obviously bad btree pointer. Since the values
come from disk, we must return an error, not just ASSERT.

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

xfs: remove boilerplate around xfs_btree_init_block

Now that xfs_btree_init_block_int is able to determine crc
status from the passed-in mp, we can determine the proper
magic as well if we are given a btree number, rather than
an explicit magic value.

Change xfs_btree_init_block[_int] callers to pass in the
btree number, and let xfs_btree_init_block_int use the
xfs_magics array via the xfs_btree_magic macro to determine
which magic value is needed. This makes all of the
if (crc) / else stanzas identical, and the if/else can be
removed, leading to a single, common init_block call.

Signed-off-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: make xfs_btree_magic more generic

Right now the xfs_btree_magic() define takes only a cursor;
change this to take crc and btnum args to make it more generically
useful, and move to a function.

This will allow xfs_btree_init_block_int callers which don't
have a cursor to make use of the xfs_magics array, which will
happen in the next patch.

Signed-off-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: make xfs btree stats less huge

Embedding a switch statement in every btree stats inc/add adds a lot
of code overhead to the core btree infrastructure paths. Stats are
supposed to be small and lightweight, but the btree stats have
become big and bloated as we've added more btrees. It needs fixing
because the reflink code will just add more overhead again.

Convert the v2 btree stats to arrays instead of independent
variables, and instead use the type to index the specific btree
array via an enum. This allows us to use array based indexing
to update the stats, rather than having to derefence variables
specific to the btree type.

If we then wrap the xfsstats structure in a union and place uint32_t
array beside it, and calculate the correct btree stats array base
array index when creating a btree cursor, we can easily access
entries in the stats structure without having to switch names based
on the btree type.

We then replace with the switch statement with a simple set of stats
wrapper macros, resulting in a significant simplification of the
btree stats code, and:

text data bss dec hex filename
48905 144 8 49057 bfa1 fs/xfs/libxfs/xfs_btree.o.old
36793 144 8 36945 9051 fs/xfs/libxfs/xfs_btree.o

it reduces the core btree infrastructure code size by close to 25%!

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>

xfs: define the on-disk refcount btree format

Start constructing the refcount btree implementation by establishing
the on-disk format and everything needed to read, write, and
manipulate the refcount btree blocks.

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

xfs: introduce refcount btree definitions

Add new per-AG refcount btree definitions to the per-AG structures.

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

xfs: count the blocks in a btree

Provide a helper method to count the number of blocks in a short form
btree. The refcount and rmap btrees need to know the number of blocks
already in use to set up their per-AG block reservations during mount.

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

xfs: create a standard btree size calculator code

Create a helper to generate AG btree height calculator functions.
This will be used (much) later when we get to the refcount btree.

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

xfs: remove xfs_btree_bigkey

Remove the xfs_btree_bigkey mess and simply make xfs_btree_key big enough
to hold both keys in-core.

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

xfs: remove the get*keys and update_keys btree ops pointers

These are internal btree functions; we don't need them to be
dispatched via function pointers. Make them static again and
just check the overlapped flag to figure out what we need to
do. The strategy behind this patch was suggested by Christoph.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

xfs: add rmap btree operations

Originally-From: Dave Chinner <dchinner@redhat.com>

Implement the generic btree operations needed to manipulate rmap
btree blocks. This is very similar to the per-ag freespace btree
implementation, and uses the AGFL for allocation and freeing of
blocks.

Adapt the rmap btree to store owner offsets within each rmap record,
and to handle the primary key being redefined as the tuple
[agblk, owner, offset]. The expansion of the primary key is crucial
to allowing multiple owners per extent.

[darrick: adapt the btree ops to deal with offsets]
[darrick: remove init_rec_from_key]
[darrick: move unwritten bit to rm_offset]

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

xfs: define the on-disk rmap btree format

Originally-From: Dave Chinner <dchinner@redhat.com>

Now we have all the surrounding call infrastructure in place, we can
start filling out the rmap btree implementation. Start with the
on-disk btree format; add everything needed to read, write and
manipulate rmap btree blocks. This prepares the way for adding the
btree operations implementation.

[darrick: record owner and offset info in rmap btree]
[darrick: fork, bmbt and unwritten state in rmap btree]
[darrick: flags are a separate field in xfs_rmap_irec]
[darrick: calculate maxlevels separately]
[darrick: move the 'unwritten' bit into unused parts of rm_offset]

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

xfs: add rmap btree stats infrastructure

Originally-From: Dave Chinner <dchinner@redhat.com>

The rmap btree will require the same stats as all the other generic
btrees, so add all the code for that now.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

xfs: introduce rmap btree definitions

Originally-From: Dave Chinner <dchinner@redhat.com>

Add new per-ag rmap btree definitions to the per-ag structures. The
rmap btree will sit in the empty slots on disk after the free space
btrees, and hence form a part of the array of space management
btrees. This requires the definition of the btree to be contiguous
with the free space btrees.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

xfs: increase XFS_BTREE_MAXLEVELS to fit the rmapbt

By my calculations, a 1,073,741,824 block AG with a 1k block size
can attain a maximum height of 9. Assuming a record size of 24
bytes, a key/ptr size of 44 bytes, and half-full btree nodes, we'd
need 53,687,092 blocks for the records and ~6 million blocks for the
keys. That requires a btree of height 9 based on the following
derivation:

Block size = 1024b
sblock CRC header = 56b
== 1024-56 = 968 bytes for tree data

rmapbt record = 24b
== 40 records per leaf block

rmapbt ptr/key = 44b
== 22 ptr/keys per block

Worst case, each block is half full, so 20 records and 11 ptrs per block.

1073741824 rmap records / 20 records per block
== 53687092 leaf blocks

53687092 leaves / 11 ptrs per block
== 4880645 level 1 blocks
== 443695 level 2 blocks
== 40336 level 3 blocks
== 3667 level 4 blocks
== 334 level 5 blocks
== 31 level 6 blocks
== 3 level 7 blocks
== 1 level 8 block

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: rename flist/free_list to dfops

Mechanical change of flist/free_list to dfops, since they're now
deferred ops, not just a freeing list.

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: change xfs_bmap_{finish,cancel,init,free} -> xfs_defer_*

Drop the compatibility shims that we were using to integrate the new
deferred operation mechanism into the existing code. No new code.

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: refactor btree owner change into a separate visit-blocks function

Refactor the btree_change_owner function into a more generic apparatus
which visits all blocks in a btree. We'll use this in a subsequent
patch for counting btree blocks for AG reservations.

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

xfs: introduce interval queries on btrees

Create a function to enable querying of btree records mapping to a
range of keys. This will be used in subsequent patches to allow
querying the reverse mapping btree to find the extents mapped to a
range of physical blocks, though the generic code can be used for
any range query.

The overlapped query range function needs to use the btree get_block
helper because the root block could be an inode, in which case
bc_bufs[nlevels-1] will be NULL.

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

xfs: support btrees with overlapping intervals for keys

On a filesystem with both reflink and reverse mapping enabled, it's
possible to have multiple rmap records referring to the same blocks on
disk. When overlapping intervals are possible, querying a classic
btree to find all records intersecting a given interval is inefficient
because we cannot use the left side of the search interval to filter
out non-matching records the same way that we can use the existing
btree key to filter out records coming after the right side of the
search interval. This will become important once we want to use the
rmap btree to rebuild BMBTs, or implement the (future) fsmap ioctl.

(For the non-overlapping case, we can perform such queries trivially
by starting at the left side of the interval and walking the tree
until we pass the right side.)

Therefore, extend the btree code to come closer to supporting
intervals as a first-class record attribute. This involves widening
the btree node's key space to store both the lowest key reachable via
the node pointer (as the btree does now) and the highest key reachable
via the same pointer and teaching the btree modifying functions to
keep the highest-key records up to date.

This behavior can be turned on via a new btree ops flag so that btrees
that cannot store overlapping intervals don't pay the overhead costs
in terms of extra code and disk format changes.

When we're deleting a record in a btree that supports overlapped
interval records and the deletion results in two btree blocks being
joined, we defer updating the high/low keys until after all possible
joining (at higher levels in the tree) have finished. At this point,
the btree pointers at all levels have been updated to remove the empty
blocks and we can update the low and high keys.

When we're doing this, we must be careful to update the keys of all
node pointers up to the root instead of stopping at the first set of
keys that don't need updating. This is because it's possible for a
single deletion to cause joining of multiple levels of tree, and so
we need to update everything going back to the root.

The diff_two_keys functions return < 0, 0, or > 0 if key1 is less than,
equal to, or greater than key2, respectively. This is consistent
with the rest of the kernel and the C library.

In btree_updkeys(), we need to evaluate the force_all parameter before
running the key diff to avoid reading uninitialized memory when we're
forcing a key update. This happens when we've allocated an empty slot
at level N + 1 to point to a new block at level N and we're in the
process of filling out the new keys.

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

xfs: add function pointers for get/update keys to the btree

Add some function pointers to bc_ops to get the btree keys for
leaf and node blocks, and to update parent keys of a block.
Convert the _btree_updkey calls to use our new pointer, and
modify the tree shape changing code to call the appropriate
get_*_keys pointer instead of _btree_copy_keys because the
overlapping btree has to calculate high key values.

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: during btree split, save new block key & ptr for future insertion

When a btree block has to be split, we pass the new block's ptr from
xfs_btree_split() back to xfs_btree_insert() via a pointer parameter;
however, we pass the block's key through the cursor's record. It is a
little weird to "initialize" a record from a key since the non-key
attributes will have garbage values.

When we go to add support for interval queries, we have to be able to
pass the lowest and highest keys accessible via a pointer. There's no
clean way to pass this back through the cursor's record field.
Therefore, pass the key directly back to xfs_btree_insert() the same
way that we pass the btree_ptr.

As a bonus, we no longer need init_rec_from_key and can drop it from the
codebase.

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

xfs: refactor btree maxlevels computation

Create a common function to calculate the maximum height of a per-AG
btree. This will eventually be used by the rmapbt and refcountbt
code to calculate appropriate maxlevels values for each. This is
important because the verifiers and the transaction block
reservations depend on accurate estimates of how many blocks are
needed to satisfy a btree split.

We were mistakenly using the max bnobt height for all the btrees,
which creates a dangerous situation since the larger records and
keys in an rmapbt make it very possible that the rmapbt will be
taller than the bnobt and so we can run out of transaction block
reservation.

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>

libxfs: refactor short btree block verification

Create xfs_btree_sblock_verify() to verify short-format btree blocks
(i.e. the per-AG btrees with 32-bit block pointers) instead of
open-coding them.

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

xfs: per-filesystem stats counter implementation

This patch modifies the stats counting macros and the callers
to those macros to properly increment, decrement, and add-to
the xfs stats counts. The counts for global and per-fs stats
are correctly advanced, and cleared by writing a "1" to the
corresponding clear file.

global counts: /sys/fs/xfs/stats/stats
per-fs counts: /sys/fs/xfs/sda*/stats/stats

global clear: /sys/fs/xfs/stats/stats_clear
per-fs clear: /sys/fs/xfs/sda*/stats/stats_clear

[dchinner: cleaned up macro variables, removed CONFIG_FS_PROC around
stats structures and macros. ]

Signed-off-by: Bill O'Donnell <billodo@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

xfs: require 64-bit sector_t

Trying to support tiny disks only and saving a bit memory might have
made sense on an SGI O2 15 years ago, but is pretty pointless today.

Remove the rarely tested codepath that uses various smaller in-memory
types to reduce our test matrix and make the codebase a little bit
smaller and less complicated.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

libxfs: move header files

Move all the header files that are shared with userspace into
libxfs. This is done as one big chunk simpy to get it done quickly.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>