Commit Graph

8497 Commits

Author SHA1 Message Date
Darrick J. Wong
0ee230dec2 xfs: scrub should set preen if attr leaf has holes
If an attr block indicates that it could use compaction, set the preen
flag to have the attr fork rebuilt, since the attr fork rebuilder can
take care of that for us.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:54 -07:00
Darrick J. Wong
e47dcf113a xfs: repair extended attributes
If the extended attributes look bad, try to sift through the rubble to
find whatever keys/values we can, stage a new attribute structure in a
temporary file and use the atomic extent swapping mechanism to commit
the results in bulk.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:53 -07:00
Darrick J. Wong
629fdaf5f5 xfs: use atomic extent swapping to fix user file fork data
Build on the code that was recently added to the temporary repair file
code so that we can atomically switch the contents of any file fork,
even if the fork is in local format.  The upcoming functions to repair
xattrs, directories, and symlinks will need that capability.

Repair can lock out access to these user files by holding IOLOCK_EXCL on
these user files.  Therefore, it is safe to drop the ILOCK of both the
file being repaired and the tempfile being used for staging, and cancel
the scrub transaction.  We do this so that we can reuse the resource
estimation and transaction allocation functions used by a regular file
exchange operation.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:53 -07:00
Darrick J. Wong
d2bd7eef4f xfs: create a blob array data structure
Create a simple 'blob array' data structure for storage of arbitrarily
sized metadata objects that will be used to reconstruct metadata.  For
the intended usage (temporarily storing extended attribute names and
values) we only have to support storing objects and retrieving them.
Use the xfile abstraction to store the attribute information in memory
that can be swapped out.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:53 -07:00
Darrick J. Wong
98339edf07 xfs: enable discarding of folios backing an xfile
Create a new xfile function to discard the page cache that's backing
part of an xfile.  The next patch wil use this to drop parts of an xfile
that aren't needed anymore.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:53 -07:00
Darrick J. Wong
fe6c9f8e48 xfs: validate explicit directory free block owners
Port the existing directory freespace block header checking function to
accept an owner number instead of an xfs_inode, then update the
callsites to use xfs_da_args.owner when possible.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:52 -07:00
Darrick J. Wong
29b41ce919 xfs: validate explicit directory block buffer owners
Port the existing directory block header checking function to accept an
owner number instead of an xfs_inode, then update the callsites to use
xfs_da_args.owner when possible.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:52 -07:00
Darrick J. Wong
cc6740ddb4 xfs: validate explicit directory data buffer owners
Port the existing directory data header checking function to accept an
owner number instead of an xfs_inode, then update the callsites to use
xfs_da_args.owner when possible.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:52 -07:00
Darrick J. Wong
402eef10a1 xfs: validate directory leaf buffer owners
Check the owner field of directory leaf blocks.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:51 -07:00
Darrick J. Wong
d44bea9b41 xfs: validate dabtree node buffer owners
Check the owner field of dabtree node blocks.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:51 -07:00
Darrick J. Wong
8c25dc728b xfs: validate attr remote value buffer owners
Check the owner field of xattr remote value blocks.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:51 -07:00
Darrick J. Wong
f4887fbc41 xfs: validate attr leaf buffer owners
Create a leaf block header checking function to validate the owner field
of xattr leaf blocks.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:51 -07:00
Darrick J. Wong
33c028ffe3 xfs: reduce indenting in xfs_attr_node_list
Reduce the indentation here so that we can add some things in the next
patch without going over the column limits.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:50 -07:00
Darrick J. Wong
17a85dc64a xfs: use the xfs_da_args owner field to set new dir/attr block owner
When we're creating leaf, data, freespace, or dabtree blocks for
directories and xattrs, use the explicit owner field (instead of the
xfs_inode) to set the owner field.  This will enable online repair to
construct replacement data structures in a temporary file without having
to change the owner fields prior to swapping the new and old structures.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:50 -07:00
Darrick J. Wong
9eef772f3a xfs: add an explicit owner field to xfs_da_args
Add an explicit owner field to xfs_da_args, which will make it easier
for online fsck to set the owner field of the temporary directory and
xattr structures that it builds to repair damaged metadata.

Note: I hopefully found all the xfs_da_args definitions by looking for
automatic stack variable declarations and xfs_da_args.dp assignments:

git grep -E '(args.*dp =|struct xfs_da_args[[:space:]]*[a-z0-9][a-z0-9]*)'

Note that callers of xfs_attr_{get,set,change} can set the owner to zero
(or leave it unset) to have the default set to args->dp.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:50 -07:00
Darrick J. Wong
abf039e2e4 xfs: online repair of realtime summaries
Repair the realtime summary data by constructing a new rtsummary file in
the scrub temporary file, then atomically swapping the contents.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:49 -07:00
Darrick J. Wong
56596d8bff xfs: teach the tempfile to set up atomic file content exchanges
Create some new routines to exchange the contents of a temporary file
created to stage a repair with another ondisk file.  This will be used
by the realtime summary repair function to commit atomically the new
rtsummary data, which will be staged in the tempfile.

The rest of XFS coordinates access to the realtime metadata inodes
solely through the ILOCK.  For repair to hold its exclusive access to
the realtime summary file, it has to allocate a single large transaction
and roll it repeatedly throughout the repair while holding the ILOCK.
In turn, this means that for now there's only a partial file mapping
exchange implementation for the temporary file because we can only work
within an existing transaction.

For now, the only tempswap functions needed here are to estimate the
resource requirements of the exchange, reserve more space/quota to an
existing transaction, and kick off the actual exchange.  The rest will
be added in a later patch in preparation for repairing xattrs and
directories.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:49 -07:00
Darrick J. Wong
e81ce42413 xfs: support preallocating and copying content into temporary files
Create the routines we need to preallocate space in a temporary ondisk
file and then copy the contents of an xfile into the tempfile.  The
upcoming rtsummary repair feature will construct the contents of a
realtime summary file in memory, after which it will want to copy all
that into the ondisk temporary file before atomically committing the new
rtsummary contents.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:49 -07:00
Darrick J. Wong
5befb047b9 xfs: add the ability to reap entire inode forks
In preparation for supporting repair of indexed file-based metadata
(such as realtime bitmaps, directories, and extended attribute data),
add a function to reap the old blocks after a metadata repair finishes.
IOWs, this is an elaborate bunmapi call that deals with crosslinked
blocks by unmapping them without freeing them, and also scans for incore
buffers to invalidate.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:49 -07:00
Darrick J. Wong
20a3c1ecc3 xfs: refactor live buffer invalidation for repairs
In an upcoming patch, we will need to be able to look for xfs_buf
objects caching file-based metadata blocks without needing to walk the
(possibly corrupt) structures to find all the buffers.  Repair already
has most of the code needed to scan the buffer cache, so hoist these
utility functions.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:48 -07:00
Darrick J. Wong
84c14ee39d xfs: create temporary files and directories for online repair
Teach the online repair code how to create temporary files or
directories.  These temporary files can be used to stage reconstructed
information until we're ready to perform an atomic extent swap to commit
the new metadata.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:48 -07:00
Darrick J. Wong
cab23a4233 xfs: hide private inodes from bulkstat and handle functions
We're about to start adding functionality that uses internal inodes that
are private to XFS.  What this means is that userspace should never be
able to access any information about these files, and should not be able
to open these files by handle.

To prevent users from ever finding the file or mis-interactions with the
security apparatus, set S_PRIVATE on the inode.  Don't allow bulkstat,
open-by-handle, or linking of S_PRIVATE files into the directory tree.
This should keep private inodes actually private.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:58:48 -07:00
Darrick J. Wong
0730e8d8ba xfs: enable logged file mapping exchange feature
Add the XFS_SB_FEAT_INCOMPAT_EXCHRANGE feature to the set of features
that we will permit when mounting a filesystem.  This turns on support
for the file range exchange feature.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:26 -07:00
Darrick J. Wong
14f1999102 xfs: capture inode generation numbers in the ondisk exchmaps log item
Per some very late review comments, capture the generation numbers of
both inodes involved in a file content exchange operation so that we
don't accidentally target files with have been reallocated.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:24 -07:00
Darrick J. Wong
b3e60f8483 xfs: support non-power-of-two rtextsize with exchange-range
The generic exchange-range alignment checks use (fast) bitmasking
operations to perform block alignment checks on the exchange parameters.
Unfortunately, bitmasks require that the alignment size be a power of
two.  This isn't true for realtime devices with a non-power-of-two
extent size, so we have to copy-pasta the generic checks using long
division for this to work properly.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:23 -07:00
Darrick J. Wong
e62941103f xfs: make file range exchange support realtime files
Now that bmap items support the realtime device, we can add the
necessary pieces to the file range exchange code to support exchanging
mappings.  All we really need to do here is adjust the blockcount
upwards to the end of the rt extent and remove the inode checks.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:22 -07:00
Darrick J. Wong
33a9be2b70 xfs: condense symbolic links after a mapping exchange operation
The previous commit added a new file mapping exchange flag that enables
us to perform post-exchange processing on file2 once we're done
exchanging the extent mappings.  Now add this ability for symlinks.

This isn't used anywhere right now, but we need to have the basic ondisk
flags in place so that a future online symlink repair feature can
salvage the remote target in a temporary link and exchange the data fork
mappings when ready.  If one file is in extents format and the other is
inline, we will have to promote both to extents format to perform the
exchange.  After the exchange, we can try to condense the fixed symlink
down to inline format if possible.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:21 -07:00
Darrick J. Wong
da165fbde2 xfs: condense directories after a mapping exchange operation
The previous commit added a new file mapping exchange flag that enables
us to perform post-swap processing on file2 once we're done exchanging
extent mappings.  Now add this ability for directories.

This isn't used anywhere right now, but we need to have the basic ondisk
flags in place so that a future online directory repair feature can
create salvaged dirents in a temporary directory and exchange the data
fork mappings when ready.  If one file is in extents format and the
other is inline, we will have to promote both to extents format to
perform the exchange.  After the exchange, we can try to condense the
fixed directory down to inline format if possible.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:20 -07:00
Darrick J. Wong
497d7a2608 xfs: condense extended attributes after a mapping exchange operation
Add a new file mapping exchange flag that enables us to perform
post-exchange processing on file2 once we're done exchanging the extent
mappings.  If we were swapping mappings between extended attribute
forks, we want to be able to convert file2's attr fork from block to
inline format.

(This implies that all fork contents are exchanged.)

This isn't used anywhere right now, but we need to have the basic ondisk
flags in place so that a future online xattr repair feature can create
salvaged attrs in a temporary file and exchange the attr fork mappings
when ready.  If one file is in extents format and the other is inline,
we will have to promote both to extents format to perform the exchange.
After the exchange, we can try to condense the fixed file's attr fork
back down to inline format if possible.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:20 -07:00
Darrick J. Wong
5fd022ec7d xfs: add error injection to test file mapping exchange recovery
Add an errortag so that we can test recovery of exchmaps log items.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:19 -07:00
Darrick J. Wong
42672471f9 xfs: bind together the front and back ends of the file range exchange code
So far, we've constructed the front end of the file range exchange code
that does all the checking; and the back end of the file mapping
exchange code that actually does the work.  Glue these two pieces
together so that we can turn on the functionality.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:18 -07:00
Darrick J. Wong
966ceafc7a xfs: create deferred log items for file mapping exchanges
Now that we've created the skeleton of a log intent item to track and
restart file mapping exchange operations, add the upper level logic to
commit intent items and turn them into concrete work recorded in the
log.  This builds on the existing bmap update intent items that have
been around for a while now.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:17 -07:00
Darrick J. Wong
6c08f434bd xfs: introduce a file mapping exchange log intent item
Introduce a new intent log item to handle exchanging mappings between
the forks of two files.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:16 -07:00
Darrick J. Wong
1518646eef xfs: create a incompat flag for atomic file mapping exchanges
Create a incompat flag so that we only attempt to process file mapping
exchange log items if the filesystem supports it, and a geometry flag to
advertise support if it's present.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:15 -07:00
Darrick J. Wong
9a64d9b310 xfs: introduce new file range exchange ioctl
Introduce a new ioctl to handle exchanging ranges of bytes
between files.  The goal here is to perform the exchange atomically with
respect to applications -- either they see the file contents before the
exchange or they see that A-B is now B-A, even if the kernel crashes.

My original goal with all this code was to make it so that online repair
can build a replacement directory or xattr structure in a temporary file
and commit the repair by atomically exchanging all the data blocks
between the two files.  However, I needed a way to test this mechanism
thoroughly, so I've been evolving an ioctl interface since then.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:14 -07:00
Darrick J. Wong
15f78aa3eb xfs: constify xfs_bmap_is_written_extent
This predicate doesn't modify the structure that's being passed in, so
we can mark it const.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:12 -07:00
Darrick J. Wong
ac5cebeed6 xfs: refactor non-power-of-two alignment checks
Create a helper function that can compute if a 64-bit number is an
integer multiple of a 32-bit number, where the 32-bit number is not
required to be an even power of two.  This is needed for some new code
for the realtime device, where we can set 37k allocation units and then
have to remap them.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:12 -07:00
Darrick J. Wong
6b700a5be9 xfs: hoist multi-fsb allocation unit detection to a helper
Replace the open-coded logic to decide if a file has a multi-fsb
allocation unit to a helper to make the code easier to read.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:11 -07:00
Darrick J. Wong
ee20808d84 xfs: create a new helper to return a file's allocation unit
Create a new helper function to calculate the fundamental allocation
unit (i.e. the smallest unit of space we can allocate) of a file.
Things are going to get hairy with range-exchange on the realtime
device, so prepare for this now.

Remove the static attribute from xfs_is_falloc_aligned since the next
patch will need it.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:10 -07:00
Darrick J. Wong
00acb28d96 xfs: declare xfs_file.c symbols in xfs_file.h
Move the two public symbols in xfs_file.c to xfs_file.h.  We're about to
add more public symbols in that source file, so let's finally create the
header file.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:09 -07:00
Darrick J. Wong
3fc4844585 xfs: move xfs_iops.c declarations out of xfs_inode.h
Similarly, move declarations of public symbols of xfs_iops.c from
xfs_inode.h to xfs_iops.h.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:08 -07:00
Darrick J. Wong
a4db266a70 xfs: move inode lease breaking functions to xfs_inode.c
The lease breaking functions operate at the scope of the entire VFS
inode, not subranges of a file.  Move them to xfs_inode.c since they're
already declared in xfs_inode.h.  This cleanup moves us closer to
having xfs_FOO.h declare only the symbols in xfs_FOO.c.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:07 -07:00
Darrick J. Wong
5302a5c8be xfs: only clear log incompat flags at clean unmount
While reviewing the online fsck patchset, someone spied the
xfs_swapext_can_use_without_log_assistance function and wondered why we
go through this inverted-bitmask dance to avoid setting the
XFS_SB_FEAT_INCOMPAT_LOG_SWAPEXT feature.

(The same principles apply to the logged extended attribute update
feature bit in the since-merged LARP series.)

The reason for this dance is that xfs_add_incompat_log_feature is an
expensive operation -- it forces the log, pushes the AIL, and then if
nobody's beaten us to it, sets the feature bit and issues a synchronous
write of the primary superblock.  That could be a one-time cost
amortized over the life of the filesystem, but the log quiesce and cover
operations call xfs_clear_incompat_log_features to remove feature bits
opportunistically.  On a moderately loaded filesystem this leads to us
cycling those bits on and off over and over, which hurts performance.

Why do we clear the log incompat bits?  Back in ~2020 I think Dave and I
had a conversation on IRC[2] about what the log incompat bits represent.
IIRC in that conversation we decided that the log incompat bits protect
unrecovered log items so that old kernels won't try to recover them and
barf.  Since a clean log has no protected log items, we could clear the
bits at cover/quiesce time.

As Dave Chinner pointed out in the thread, clearing log incompat bits at
unmount time has positive effects for golden root disk image generator
setups, since the generator could be running a newer kernel than what
gets written to the golden image -- if there are log incompat fields set
in the golden image that was generated by a newer kernel/OS image
builder then the provisioning host cannot mount the filesystem even
though the log is clean and recovery is unnecessary to mount the
filesystem.

Given that it's expensive to set log incompat bits, we really only want
to do that once per bit per mount.  Therefore, I propose that we only
clear log incompat bits as part of writing a clean unmount record.  Do
this by adding an operational state flag to the xfs mount that guards
whether or not the feature bit clearing can actually take place.

This eliminates the l_incompat_users rwsem that we use to protect a log
cleaning operation from clearing a feature bit that a frontend thread is
trying to set -- this lock adds another way to fail w.r.t. locking.  For
the swapext series, I shard that into multiple locks just to work around
the lockdep complaints, and that's fugly.

Link: https://lore.kernel.org/linux-xfs/20240131230043.GA6180@frogsfrogsfrogs/
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2024-04-15 14:54:06 -07:00
Darrick J. Wong
98a778b425 xfs: fix error bailout in xrep_abt_build_new_trees
Dan Carpenter reports:

"Commit 4bdfd7d157 ("xfs: repair free space btrees") from Dec 15,
2023 (linux-next), leads to the following Smatch static checker
warning:

        fs/xfs/scrub/alloc_repair.c:781 xrep_abt_build_new_trees()
        warn: missing unwind goto?"

That's a bug, so let's fix it.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: 4bdfd7d157 ("xfs: repair free space btrees")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:06 -07:00
Darrick J. Wong
21ad2d0364 xfs: fix potential AGI <-> ILOCK ABBA deadlock in xrep_dinode_findmode_walk_directory
xfs/399 found the following deadlock when fuzzing core.mode = ones:

/proc/20506/task/20558/stack :
[<0>] xfs_ilock+0xa0/0x240 [xfs]
[<0>] xfs_ilock_data_map_shared+0x1b/0x20 [xfs]
[<0>] xrep_dinode_findmode_walk_directory+0x69/0xe0 [xfs]
[<0>] xrep_dinode_find_mode+0x103/0x2a0 [xfs]
[<0>] xrep_dinode_mode+0x7c/0x120 [xfs]
[<0>] xrep_dinode_core+0xed/0x2b0 [xfs]
[<0>] xrep_dinode_problems+0x10/0x80 [xfs]
[<0>] xrep_inode+0x6c/0xc0 [xfs]
[<0>] xrep_attempt+0x64/0x1d0 [xfs]
[<0>] xfs_scrub_metadata+0x365/0x840 [xfs]
[<0>] xfs_scrubv_metadata+0x282/0x430 [xfs]
[<0>] xfs_ioc_scrubv_metadata+0x149/0x1a0 [xfs]
[<0>] xfs_file_ioctl+0xc68/0x1780 [xfs]
/proc/20506/task/20559/stack :
[<0>] xfs_buf_lock+0x3b/0x110 [xfs]
[<0>] xfs_buf_find_lock+0x66/0x1c0 [xfs]
[<0>] xfs_buf_get_map+0x208/0xc00 [xfs]
[<0>] xfs_buf_read_map+0x5d/0x2c0 [xfs]
[<0>] xfs_trans_read_buf_map+0x1b0/0x4c0 [xfs]
[<0>] xfs_read_agi+0xbd/0x190 [xfs]
[<0>] xfs_ialloc_read_agi+0x47/0x160 [xfs]
[<0>] xfs_imap_lookup+0x69/0x1f0 [xfs]
[<0>] xfs_imap+0x1fc/0x3d0 [xfs]
[<0>] xfs_iget+0x357/0xd50 [xfs]
[<0>] xchk_dir_actor+0x16e/0x330 [xfs]
[<0>] xchk_dir_walk_block+0x164/0x1e0 [xfs]
[<0>] xchk_dir_walk+0x13a/0x190 [xfs]
[<0>] xchk_directory+0x1a2/0x2b0 [xfs]
[<0>] xfs_scrub_metadata+0x2f4/0x840 [xfs]
[<0>] xfs_scrubv_metadata+0x282/0x430 [xfs]
[<0>] xfs_ioc_scrubv_metadata+0x149/0x1a0 [xfs]
[<0>] xfs_file_ioctl+0xc68/0x1780 [xfs]

Thread 20558 holds an AGI buffer and is trying to grab the ILOCK of the
root directory.  Thread 20559 holds the root directory ILOCK and is
trying to grab the AGI of an inode that is one of the root directory's
children.  The AGI held by 20558 is the same buffer that 20559 is trying
to acquire.  In other words, this is an ABBA deadlock.

In general, the lock order is ILOCK and then AGI -- rename does this
while preparing for an operation involving whiteouts or renaming files
out of existence; and unlink does this when moving an inode to the
unlinked list.  The only place where we do it in the opposite order is
on the child during an icreate, but at that point the child is marked
INEW and is not visible to other threads.

Work around this deadlock by replacing the blocking ilock attempt with a
nonblocking loop that aborts after 30 seconds.  Relax for a jiffy after
a failed lock attempt.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:05 -07:00
Darrick J. Wong
2afd5276d3 xfs: fix an AGI lock acquisition ordering problem in xrep_dinode_findmode
While reviewing the next patch which fixes an ABBA deadlock between the
AGI and a directory ILOCK, someone asked a question about why we're
holding the AGI in the first place.  The reason for that is to quiesce
the inode structures for that AG while we do a repair.

I then realized that the xrep_dinode_findmode invokes xchk_iscan_iter,
which walks the inobts (and hence the AGIs) to find all the inodes.
This itself is also an ABBA vector, since the damaged inode could be in
AG 5, which we hold while we scan AG 0 for directories.  5 -> 0 is not
allowed.

To address this, modify the iscan to allow trylock of the AGI buffer
using the flags argument to xfs_ialloc_read_agi that the previous patch
added.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:04 -07:00
Darrick J. Wong
549d3c9a29 xfs: pass xfs_buf lookup flags to xfs_*read_agi
Allow callers to pass buffer lookup flags to xfs_read_agi and
xfs_ialloc_read_agi.  This will be used in the next patch to fix a
deadlock in the online fsck inode scanner.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-15 14:54:03 -07:00
Linus Torvalds
9520c192e8 Bug fixes for 6.9-rc3:
* Allow creating new links to special files which were not associated with a
    project quota.
 
 Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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Merge tag 'xfs-6.9-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs fix from Chandan Babu:

 - Allow creating new links to special files which were not associated
   with a project quota

* tag 'xfs-6.9-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: allow cross-linking special files without project quota
2024-04-06 09:14:18 -07:00
Linus Torvalds
fae0268777 vfs-6.9-rc3.fixes
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Merge tag 'vfs-6.9-rc3.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs fixes from Christian Brauner:
 "This contains a few small fixes. This comes with some delay because I
  wanted to wait on people running their reproducers and the Easter
  Holidays meant that those replies came in a little later than usual:

   - Fix handling of preventing writes to mounted block devices.

     Since last kernel we allow to prevent writing to mounted block
     devices provided CONFIG_BLK_DEV_WRITE_MOUNTED isn't set and the
     block device is opened with restricted writes. When we switched to
     opening block devices as files we altered the mechanism by which we
     recognize when a block device has been opened with write
     restrictions.

     The detection logic assumed that only read-write mounted
     filesystems would apply write restrictions to their block devices
     from other openers. That of course is not true since it also makes
     sense to apply write restrictions for filesystems that are
     read-only.

     Fix the detection logic using an FMODE_* bit. We still have a few
     left since we freed up a couple a while ago. I also picked up a
     patch to free up four additional FMODE_* bits scheduled for the
     next merge window.

   - Fix counting the number of writers to a block device. This just
     changes the logic to be consistent.

   - Fix a bug in aio causing a NULL pointer derefernce after we
     implemented batched processing in aio.

   - Finally, add the changes we discussed that allows to yield block
     devices early even though file closing itself is deferred.

     This also allows us to remove two holder operations to get and
     release the holder to align lifetime of file and holder of the
     block device"

* tag 'vfs-6.9-rc3.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  aio: Fix null ptr deref in aio_complete() wakeup
  fs,block: yield devices early
  block: count BLK_OPEN_RESTRICT_WRITES openers
  block: handle BLK_OPEN_RESTRICT_WRITES correctly
2024-04-05 09:47:26 -07:00
Andrey Albershteyn
e23d7e82b7 xfs: allow cross-linking special files without project quota
There's an issue that if special files is created before quota
project is enabled, then it's not possible to link this file. This
works fine for normal files. This happens because xfs_quota skips
special files (no ioctls to set necessary flags). The check for
having the same project ID for source and destination then fails as
source file doesn't have any ID.

mkfs.xfs -f /dev/sda
mount -o prjquota /dev/sda /mnt/test

mkdir /mnt/test/foo
mkfifo /mnt/test/foo/fifo1

xfs_quota -xc "project -sp /mnt/test/foo 9" /mnt/test
> Setting up project 9 (path /mnt/test/foo)...
> xfs_quota: skipping special file /mnt/test/foo/fifo1
> Processed 1 (/etc/projects and cmdline) paths for project 9 with recursion depth infinite (-1).

ln /mnt/test/foo/fifo1 /mnt/test/foo/fifo1_link
> ln: failed to create hard link '/mnt/test/testdir/fifo1_link' => '/mnt/test/testdir/fifo1': Invalid cross-device link

mkfifo /mnt/test/foo/fifo2
ln /mnt/test/foo/fifo2 /mnt/test/foo/fifo2_link

Fix this by allowing linking of special files to the project quota
if special files doesn't have any ID set (ID = 0).

Signed-off-by: Andrey Albershteyn <aalbersh@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-04-01 11:55:49 +05:30