BMC/Intel-BMC/linux.git/fs/xfs, branch dev-5.10-intel

xfs: fix return of uninitialized value in variable error

2021-05-14T07:50:34+00:00

[ Upstream commit 3b6dd9a9aeeada19d0c820ff68e979243a888bb6 ] A previous commit removed a call to xfs_attr3_leaf_read that assigned an error return code to variable error. We now have a few early error return paths to label 'out' that return error if error is set; however error now is uninitialized so potentially garbage is being returned. Fix this by setting error to zero to restore the original behaviour where error was zero at the label 'restart'. Addresses-Coverity: ("Uninitialized scalar variable") Fixes: 07120f1abdff ("xfs: Add xfs_has_attr and subroutines") Signed-off-by: Colin Ian King Reviewed-by: Brian Foster Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Signed-off-by: Sasha Levin

xfs: Fix assert failure in xfs_setattr_size()

2021-03-07T11:34:05+00:00

commit 88a9e03beef22cc5fabea344f54b9a0dfe63de08 upstream. An assert failure is triggered by syzkaller test due to ATTR_KILL_PRIV is not cleared before xfs_setattr_size. As ATTR_KILL_PRIV is not checked/used by xfs_setattr_size, just remove it from the assert. Signed-off-by: Yumei Huang Reviewed-by: Brian Foster Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Signed-off-by: Greg Kroah-Hartman

xfs: revert "xfs: fix rmap key and record comparison functions"

2020-11-19T23:17:50+00:00

This reverts commit 6ff646b2ceb0eec916101877f38da0b73e3a5b7f. Your maintainer committed a major braino in the rmap code by adding the attr fork, bmbt, and unwritten extent usage bits into rmap record key comparisons. While XFS uses the usage bits *in the rmap records* for cross-referencing metadata in xfs_scrub and xfs_repair, it only needs the owner and offset information to distinguish between reverse mappings of the same physical extent into the data fork of a file at multiple offsets. The other bits are not important for key comparisons for index lookups, and never have been. Eric Sandeen reports that this causes regressions in generic/299, so undo this patch before it does more damage. Reported-by: Eric Sandeen Fixes: 6ff646b2ceb0 ("xfs: fix rmap key and record comparison functions") Signed-off-by: Darrick J. Wong Reviewed-by: Eric Sandeen

xfs: don't allow NOWAIT DIO across extent boundaries

2020-11-19T16:59:11+00:00

Jens has reported a situation where partial direct IOs can be issued and completed yet still return -EAGAIN. We don't want this to report a short IO as we want XFS to complete user DIO entirely or not at all. This partial IO situation can occur on a write IO that is split across an allocated extent and a hole, and the second mapping is returning EAGAIN because allocation would be required. The trivial reproducer: $ sudo xfs_io -fdt -c "pwrite 0 4k" -c "pwrite -V 1 -b 8k -N 0 8k" /mnt/scr/foo wrote 4096/4096 bytes at offset 0 4 KiB, 1 ops; 0.0001 sec (27.509 MiB/sec and 7042.2535 ops/sec) pwrite: Resource temporarily unavailable $ The pwritev2(0, 8kB, RWF_NOWAIT) call returns EAGAIN having done the first 4kB write: xfs_file_direct_write: dev 259:1 ino 0x83 size 0x1000 offset 0x0 count 0x2000 iomap_apply: dev 259:1 ino 0x83 pos 0 length 8192 flags WRITE|DIRECT|NOWAIT (0x31) ops xfs_direct_write_iomap_ops caller iomap_dio_rw actor iomap_dio_actor xfs_ilock_nowait: dev 259:1 ino 0x83 flags ILOCK_SHARED caller xfs_ilock_for_iomap xfs_iunlock: dev 259:1 ino 0x83 flags ILOCK_SHARED caller xfs_direct_write_iomap_begin xfs_iomap_found: dev 259:1 ino 0x83 size 0x1000 offset 0x0 count 8192 fork data startoff 0x0 startblock 24 blockcount 0x1 iomap_apply_dstmap: dev 259:1 ino 0x83 bdev 259:1 addr 102400 offset 0 length 4096 type MAPPED flags DIRTY Here the first iomap loop has mapped the first 4kB of the file and issued the IO, and we enter the second iomap_apply loop: iomap_apply: dev 259:1 ino 0x83 pos 4096 length 4096 flags WRITE|DIRECT|NOWAIT (0x31) ops xfs_direct_write_iomap_ops caller iomap_dio_rw actor iomap_dio_actor xfs_ilock_nowait: dev 259:1 ino 0x83 flags ILOCK_SHARED caller xfs_ilock_for_iomap xfs_iunlock: dev 259:1 ino 0x83 flags ILOCK_SHARED caller xfs_direct_write_iomap_begin And we exit with -EAGAIN out because we hit the allocate case trying to make the second 4kB block. Then IO completes on the first 4kB and the original IO context completes and unlocks the inode, returning -EAGAIN to userspace: xfs_end_io_direct_write: dev 259:1 ino 0x83 isize 0x1000 disize 0x1000 offset 0x0 count 4096 xfs_iunlock: dev 259:1 ino 0x83 flags IOLOCK_SHARED caller xfs_file_dio_aio_write There are other vectors to the same problem when we re-enter the mapping code if we have to make multiple mappinfs under NOWAIT conditions. e.g. failing trylocks, COW extents being found, allocation being required, and so on. Avoid all these potential problems by only allowing IOMAP_NOWAIT IO to go ahead if the mapping we retrieve for the IO spans an entire allocated extent. This avoids the possibility of subsequent mappings to complete the IO from triggering NOWAIT semantics by any means as NOWAIT IO will now only enter the mapping code once per NOWAIT IO. Reported-and-tested-by: Jens Axboe Signed-off-by: Dave Chinner Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong

xfs: return corresponding errcode if xfs_initialize_perag() fail

2020-11-18T17:23:51+00:00

In xfs_initialize_perag(), if kmem_zalloc(), xfs_buf_hash_init(), or radix_tree_preload() failed, the returned value 'error' is not set accordingly. Reported-as-fixing: 8b26c5825e02 ("xfs: handle ENOMEM correctly during initialisation of perag structures") Fixes: 9b2471797942 ("xfs: cache unlinked pointers in an rhashtable") Reported-by: Hulk Robot Signed-off-by: Yu Kuai Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong

xfs: ensure inobt record walks always make forward progress

2020-11-18T17:23:51+00:00

The aim of the inode btree record iterator function is to call a callback on every record in the btree. To avoid having to tear down and recreate the inode btree cursor around every callback, it caches a certain number of records in a memory buffer. After each batch of callback invocations, we have to perform a btree lookup to find the next record after where we left off. However, if the keys of the inode btree are corrupt, the lookup might put us in the wrong part of the inode btree, causing the walk function to loop forever. Therefore, we add extra cursor tracking to make sure that we never go backwards neither when performing the lookup nor when jumping to the next inobt record. This also fixes an off by one error where upon resume the lookup should have been for the inode /after/ the point at which we stopped. Found by fuzzing xfs/460 with keys[2].startino = ones causing bulkstat and quotacheck to hang. Fixes: a211432c27ff ("xfs: create simplified inode walk function") Signed-off-by: Darrick J. Wong Reviewed-by: Chandan Babu R

xfs: fix forkoff miscalculation related to XFS_LITINO(mp)

2020-11-18T17:23:51+00:00

Currently, commit e9e2eae89ddb dropped a (int) decoration from XFS_LITINO(mp), and since sizeof() expression is also involved, the result of XFS_LITINO(mp) is simply as the size_t type (commonly unsigned long). Considering the expression in xfs_attr_shortform_bytesfit(): offset = (XFS_LITINO(mp) - bytes) >> 3; let "bytes" be (int)340, and "XFS_LITINO(mp)" be (unsigned long)336. on 64-bit platform, the expression is offset = ((unsigned long)336 - (int)340) >> 3 = (int)(0xfffffffffffffffcUL >> 3) = -1 but on 32-bit platform, the expression is offset = ((unsigned long)336 - (int)340) >> 3 = (int)(0xfffffffcUL >> 3) = 0x1fffffff instead. so offset becomes a large positive number on 32-bit platform, and cause xfs_attr_shortform_bytesfit() returns maxforkoff rather than 0. Therefore, one result is "ASSERT(new_size <= XFS_IFORK_SIZE(ip, whichfork));" assertion failure in xfs_idata_realloc(), which was also the root cause of the original bugreport from Dennis, see: https://bugzilla.redhat.com/show_bug.cgi?id=1894177 And it can also be manually triggered with the following commands: $ touch a; $ setfattr -n user.0 -v "`seq 0 80`" a; $ setfattr -n user.1 -v "`seq 0 80`" a on 32-bit platform. Fix the case in xfs_attr_shortform_bytesfit() by bailing out "XFS_LITINO(mp) < bytes" in advance suggested by Eric and a misleading comment together with this bugfix suggested by Darrick. It seems the other users of XFS_LITINO(mp) are not impacted. Fixes: e9e2eae89ddb ("xfs: only check the superblock version for dinode size calculation") Cc: # 5.7+ Reported-and-tested-by: Dennis Gilmore Reviewed-by: Christoph Hellwig Signed-off-by: Gao Xiang Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong

xfs: directory scrub should check the null bestfree entries too

2020-11-18T17:23:50+00:00

Teach the directory scrubber to check all the bestfree entries, including the null ones. We want to be able to detect the case where the entry is null but there actually /is/ a directory data block. Found by fuzzing lbests[0] = ones in xfs/391. Fixes: df481968f33b ("xfs: scrub directory freespace") Signed-off-by: Darrick J. Wong Reviewed-by: Chandan Babu R Reviewed-by: Christoph Hellwig

xfs: strengthen rmap record flags checking

2020-11-18T17:23:50+00:00

We always know the correct state of the rmap record flags (attr, bmbt, unwritten) so check them by direct comparison. Fixes: d852657ccfc0 ("xfs: cross-reference reverse-mapping btree") Signed-off-by: Darrick J. Wong Reviewed-by: Chandan Babu R Reviewed-by: Christoph Hellwig

xfs: fix the minrecs logic when dealing with inode root child blocks

2020-11-18T17:23:50+00:00

The comment and logic in xchk_btree_check_minrecs for dealing with inode-rooted btrees isn't quite correct. While the direct children of the inode root are allowed to have fewer records than what would normally be allowed for a regular ondisk btree block, this is only true if there is only one child block and the number of records don't fit in the inode root. Fixes: 08a3a692ef58 ("xfs: btree scrub should check minrecs") Signed-off-by: Darrick J. Wong Reviewed-by: Chandan Babu R Reviewed-by: Christoph Hellwig