Commit Graph

5938 Commits

Author SHA1 Message Date
Darrick J. Wong c874390551 xfs: verify buffer contents when we skip log replay
commit 22ed903eee upstream.

syzbot detected a crash during log recovery:

XFS (loop0): Mounting V5 Filesystem bfdc47fc-10d8-4eed-a562-11a831b3f791
XFS (loop0): Torn write (CRC failure) detected at log block 0x180. Truncating head block from 0x200.
XFS (loop0): Starting recovery (logdev: internal)
==================================================================
BUG: KASAN: slab-out-of-bounds in xfs_btree_lookup_get_block+0x15c/0x6d0 fs/xfs/libxfs/xfs_btree.c:1813
Read of size 8 at addr ffff88807e89f258 by task syz-executor132/5074

CPU: 0 PID: 5074 Comm: syz-executor132 Not tainted 6.2.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106
 print_address_description+0x74/0x340 mm/kasan/report.c:306
 print_report+0x107/0x1f0 mm/kasan/report.c:417
 kasan_report+0xcd/0x100 mm/kasan/report.c:517
 xfs_btree_lookup_get_block+0x15c/0x6d0 fs/xfs/libxfs/xfs_btree.c:1813
 xfs_btree_lookup+0x346/0x12c0 fs/xfs/libxfs/xfs_btree.c:1913
 xfs_btree_simple_query_range+0xde/0x6a0 fs/xfs/libxfs/xfs_btree.c:4713
 xfs_btree_query_range+0x2db/0x380 fs/xfs/libxfs/xfs_btree.c:4953
 xfs_refcount_recover_cow_leftovers+0x2d1/0xa60 fs/xfs/libxfs/xfs_refcount.c:1946
 xfs_reflink_recover_cow+0xab/0x1b0 fs/xfs/xfs_reflink.c:930
 xlog_recover_finish+0x824/0x920 fs/xfs/xfs_log_recover.c:3493
 xfs_log_mount_finish+0x1ec/0x3d0 fs/xfs/xfs_log.c:829
 xfs_mountfs+0x146a/0x1ef0 fs/xfs/xfs_mount.c:933
 xfs_fs_fill_super+0xf95/0x11f0 fs/xfs/xfs_super.c:1666
 get_tree_bdev+0x400/0x620 fs/super.c:1282
 vfs_get_tree+0x88/0x270 fs/super.c:1489
 do_new_mount+0x289/0xad0 fs/namespace.c:3145
 do_mount fs/namespace.c:3488 [inline]
 __do_sys_mount fs/namespace.c:3697 [inline]
 __se_sys_mount+0x2d3/0x3c0 fs/namespace.c:3674
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f89fa3f4aca
Code: 83 c4 08 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffd5fb5ef8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00646975756f6e2c RCX: 00007f89fa3f4aca
RDX: 0000000020000100 RSI: 0000000020009640 RDI: 00007fffd5fb5f10
RBP: 00007fffd5fb5f10 R08: 00007fffd5fb5f50 R09: 000000000000970d
R10: 0000000000200800 R11: 0000000000000206 R12: 0000000000000004
R13: 0000555556c6b2c0 R14: 0000000000200800 R15: 00007fffd5fb5f50
 </TASK>

The fuzzed image contains an AGF with an obviously garbage
agf_refcount_level value of 32, and a dirty log with a buffer log item
for that AGF.  The ondisk AGF has a higher LSN than the recovered log
item.  xlog_recover_buf_commit_pass2 reads the buffer, compares the
LSNs, and decides to skip replay because the ondisk buffer appears to be
newer.

Unfortunately, the ondisk buffer is corrupt, but recovery just read the
buffer with no buffer ops specified:

	error = xfs_buf_read(mp->m_ddev_targp, buf_f->blf_blkno,
			buf_f->blf_len, buf_flags, &bp, NULL);

Skipping the buffer leaves its contents in memory unverified.  This sets
us up for a kernel crash because xfs_refcount_recover_cow_leftovers
reads the buffer (which is still around in XBF_DONE state, so no read
verification) and creates a refcountbt cursor of height 32.  This is
impossible so we run off the end of the cursor object and crash.

Fix this by invoking the verifier on all skipped buffers and aborting
log recovery if the ondisk buffer is corrupt.  It might be smarter to
force replay the log item atop the buffer and then see if it'll pass the
write verifier (like ext4 does) but for now let's go with the
conservative option where we stop immediately.

Link: https://syzkaller.appspot.com/bug?extid=7e9494b8b399902e994e
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-28 10:18:42 +02:00
Kees Cook 0638dcc7e7 treewide: Remove uninitialized_var() usage
commit 3f649ab728 upstream.

Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
	xargs perl -pi -e \
		's/\buninitialized_var\(([^\)]+)\)/\1/g;
		 s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-09 10:29:01 +02:00
Gao Xiang 7f2b8046da xfs: fix forkoff miscalculation related to XFS_LITINO(mp)
commit ada49d64fb upstream.

Currently, commit e9e2eae89d 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: e9e2eae89d ("xfs: only check the superblock version for dinode size calculation")
Cc: <stable@vger.kernel.org> # 5.7+
Reported-and-tested-by: Dennis Gilmore <dgilmore@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-26 11:24:06 +02:00
Darrick J. Wong 8795936437 xfs: force log and push AIL to clear pinned inodes when aborting mount
commit d336f7ebc6 upstream.

[ Slightly modify fs/xfs/xfs_mount.c to resolve merge conflicts ]

If we allocate quota inodes in the process of mounting a filesystem but
then decide to abort the mount, it's possible that the quota inodes are
sitting around pinned by the log.  Now that inode reclaim relies on the
AIL to flush inodes, we have to force the log and push the AIL in
between releasing the quota inodes and kicking off reclaim to tear down
all the incore inodes.  Do this by extracting the bits we need from the
unmount path and reusing them.  As an added bonus, failed writes during
a failed mount will not retry forever now.

This was originally found during a fuzz test of metadata directories
(xfs/1546), but the actual symptom was that reclaim hung up on the quota
inodes.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 12:07:38 +02:00
Brian Foster c76dd36875 xfs: don't reuse busy extents on extent trim
commit 06058bc405 upstream.

Freed extents are marked busy from the point the freeing transaction
commits until the associated CIL context is checkpointed to the log.
This prevents reuse and overwrite of recently freed blocks before
the changes are committed to disk, which can lead to corruption
after a crash. The exception to this rule is that metadata
allocation is allowed to reuse busy extents because metadata changes
are also logged.

As of commit 97d3ac75e5 ("xfs: exact busy extent tracking"), XFS
has allowed modification or complete invalidation of outstanding
busy extents for metadata allocations. This implementation assumes
that use of the associated extent is imminent, which is not always
the case. For example, the trimmed extent might not satisfy the
minimum length of the allocation request, or the allocation
algorithm might be involved in a search for the optimal result based
on locality.

generic/019 reproduces a corruption caused by this scenario. First,
a metadata block (usually a bmbt or symlink block) is freed from an
inode. A subsequent bmbt split on an unrelated inode attempts a near
mode allocation request that invalidates the busy block during the
search, but does not ultimately allocate it. Due to the busy state
invalidation, the block is no longer considered busy to subsequent
allocation. A direct I/O write request immediately allocates the
block and writes to it. Finally, the filesystem crashes while in a
state where the initial metadata block free had not committed to the
on-disk log. After recovery, the original metadata block is in its
original location as expected, but has been corrupted by the
aforementioned dio.

This demonstrates that it is fundamentally unsafe to modify busy
extent state for extents that are not guaranteed to be allocated.
This applies to pretty much all of the code paths that currently
trim busy extents for one reason or another. Therefore to address
this problem, drop the reuse mechanism from the busy extent trim
path. This code already knows how to return partial non-busy ranges
of the targeted free extent and higher level code tracks the busy
state of the allocation attempt. If a block allocation fails where
one or more candidate extents is busy, we force the log and retry
the allocation.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 12:07:38 +02:00
Brian Foster 4679b73a8e xfs: consider shutdown in bmapbt cursor delete assert
commit 1cd738b13a upstream.

[ Slightly modify fs/xfs/libxfs/xfs_btree.c to resolve merge conflicts ]

The assert in xfs_btree_del_cursor() checks that the bmapbt block
allocation field has been handled correctly before the cursor is
freed. This field is used for accurate calculation of indirect block
reservation requirements (for delayed allocations), for example.
generic/019 reproduces a scenario where this assert fails because
the filesystem has shutdown while in the middle of a bmbt record
insertion. This occurs after a bmbt block has been allocated via the
cursor but before the higher level bmap function (i.e.
xfs_bmap_add_extent_hole_real()) completes and resets the field.

Update the assert to accommodate the transient state if the
filesystem has shutdown. While here, clean up the indentation and
comments in the function.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 12:07:38 +02:00
Darrick J. Wong 9355fd118b xfs: shut down the filesystem if we screw up quota reservation
commit 2a4bdfa855 upstream.

If we ever screw up the quota reservations enough to trip the
assertions, something's wrong with the quota code.  Shut down the
filesystem when this happens, because this is corruption.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 12:07:38 +02:00
Darrick J. Wong 48f75df5b3 xfs: report corruption only as a regular error
commit 6519f708cc uptream.

[ Slightly modify fs/xfs/xfs_linux.h to resolve merge conflicts ]

Redefine XFS_IS_CORRUPT so that it reports corruptions only via
xfs_corruption_report.  Since these are on-disk contents (and not checks
of internal state), we don't ever want to panic the kernel.  This also
amends the corruption report to recommend unmounting and running
xfs_repair.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 12:07:38 +02:00
Jeffrey Mitchell 3cce34ceb2 xfs: set inode size after creating symlink
commit 8aa921a953 upstream.

When XFS creates a new symlink, it writes its size to disk but not to the
VFS inode. This causes i_size_read() to return 0 for that symlink until
it is re-read from disk, for example when the system is rebooted.

I found this inconsistency while protecting directories with eCryptFS.
The command "stat path/to/symlink/in/ecryptfs" will report "Size: 0" if
the symlink was created after the last reboot on an XFS root.

Call i_size_write() in xfs_symlink()

Signed-off-by: Jeffrey Mitchell <jeffrey.mitchell@starlab.io>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 12:07:38 +02:00
Christoph Hellwig e76bd6da51 xfs: fix up non-directory creation in SGID directories
commit 01ea173e10 upstream.

XFS always inherits the SGID bit if it is set on the parent inode, while
the generic inode_init_owner does not do this in a few cases where it can
create a possible security problem, see commit 0fa3ecd878
("Fix up non-directory creation in SGID directories") for details.

Switch XFS to use the generic helper for the normal path to fix this,
just keeping the simple field inheritance open coded for the case of the
non-sgid case with the bsdgrpid mount option.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: Christian Brauner <christian.brauner@ubuntu.com>
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>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 12:07:37 +02:00
Christoph Hellwig ad6613c984 xfs: remove the di_version field from struct icdinode
commit 6471e9c5e7 upstream.

We know the version is 3 if on a v5 file system.   For earlier file
systems formats we always upgrade the remaining v1 inodes to v2 and
thus only use v2 inodes.  Use the xfs_sb_version_has_large_dinode
helper to check if we deal with small or large dinodes, and thus
remove the need for the di_version field in struct icdinode.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 12:07:37 +02:00
Christoph Hellwig ca4533c951 xfs: simplify a check in xfs_ioctl_setattr_check_cowextsize
commit 5e28aafe70 upstream.

Only v5 file systems can have the reflink feature, and those will
always use the large dinode format.  Remove the extra check for the
inode version.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 12:07:37 +02:00
Christoph Hellwig e078b3de3e xfs: simplify di_flags2 inheritance in xfs_ialloc
commit b3d1d37544 upstream.

di_flags2 is initialized to zero for v4 and earlier file systems.  This
means di_flags2 can only be non-zero for a v5 file systems, in which
case both the parent and child inodes can store the field.  Remove the
extra di_version check, and also remove the rather pointless local
di_flags2 variable while at it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 12:07:37 +02:00
Christoph Hellwig 0c553917b6 xfs: only check the superblock version for dinode size calculation
commit e9e2eae89d upstream.

The size of the dinode structure is only dependent on the file system
version, so instead of checking the individual inode version just use
the newly added xfs_sb_version_has_large_dinode helper, and simplify
various calling conventions.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 12:07:37 +02:00
Christoph Hellwig 90aab52d06 xfs: add a new xfs_sb_version_has_v3inode helper
commit b81b79f4ed upstream.

Add a new wrapper to check if a file system supports the v3 inode format
with a larger dinode core.  Previously we used xfs_sb_version_hascrc for
that, which is technically correct but a little confusing to read.

Also move xfs_dinode_good_version next to xfs_sb_version_has_v3inode
so that we have one place that documents the superblock version to
inode version relationship.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 12:07:37 +02:00
Christoph Hellwig edd36a57b4 xfs: remove the kuid/kgid conversion wrappers
commit ba8adad5d0 upstream.

Remove the XFS wrappers for converting from and to the kuid/kgid types.
Mostly this means switching to VFS i_{u,g}id_{read,write} helpers, but
in a few spots the calls to the conversion functions is open coded.
To match the use of sb->s_user_ns in the helpers and other file systems,
sb->s_user_ns is also used in the quota code.  The ACL code already does
the conversion in a grotty layering violation in the VFS xattr code,
so it keeps using init_user_ns for the identity mapping.

Signed-off-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>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 12:07:37 +02:00
Christoph Hellwig 3ef81874f7 xfs: remove the icdinode di_uid/di_gid members
commit 542951592c upstream.

Use the Linux inode i_uid/i_gid members everywhere and just convert
from/to the scalar value when reading or writing the on-disk inode.

Signed-off-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>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 12:07:37 +02:00
Christoph Hellwig cc508a41ae xfs: ensure that the inode uid/gid match values match the icdinode ones
commit 3d8f282150 upstream.

Instead of only synchronizing the uid/gid values in xfs_setup_inode,
ensure that they always match to prepare for removing the icdinode
fields.

Signed-off-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>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 12:07:37 +02:00
Christoph Hellwig 7a9dc79771 xfs: merge the projid fields in struct xfs_icdinode
commit de7a866fd4 upstream.

There is no point in splitting the fields like this in an purely
in-memory structure.

Signed-off-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>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 12:07:37 +02:00
Kaixu Xia 4f3252e7e1 xfs: show the proper user quota options
commit 237d7887ae upstream.

The quota option 'usrquota' should be shown if both the XFS_UQUOTA_ACCT
and XFS_UQUOTA_ENFD flags are set. The option 'uqnoenforce' should be
shown when only the XFS_UQUOTA_ACCT flag is set. The current code logic
seems wrong, Fix it and show proper options.

Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 12:07:37 +02:00
Brian Foster 85eda80883 xfs: sync lazy sb accounting on quiesce of read-only mounts
commit 50d25484be upstream.

[ Modify xfs_log_unmount_write() to return zero when the log is in a read-only
state ]

xfs_log_sbcount() syncs the superblock specifically to accumulate
the in-core percpu superblock counters and commit them to disk. This
is required to maintain filesystem consistency across quiesce
(freeze, read-only mount/remount) or unmount when lazy superblock
accounting is enabled because individual transactions do not update
the superblock directly.

This mechanism works as expected for writable mounts, but
xfs_log_sbcount() skips the update for read-only mounts. Read-only
mounts otherwise still allow log recovery and write out an unmount
record during log quiesce. If a read-only mount performs log
recovery, it can modify the in-core superblock counters and write an
unmount record when the filesystem unmounts without ever syncing the
in-core counters. This leaves the filesystem with a clean log but in
an inconsistent state with regard to lazy sb counters.

Update xfs_log_sbcount() to use the same logic
xfs_log_unmount_write() uses to determine when to write an unmount
record. This ensures that lazy accounting is always synced before
the log is cleaned. Refactor this logic into a new helper to
distinguish between a writable filesystem and a writable log.
Specifically, the log is writable unless the filesystem is mounted
with the norecovery mount option, the underlying log device is
read-only, or the filesystem is shutdown. Drop the freeze state
check because the update is already allowed during the freezing
process and no context calls this function on an already frozen fs.
Also, retain the shutdown check in xfs_log_unmount_write() to catch
the case where the preceding log force might have triggered a
shutdown.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Gao Xiang <hsiangkao@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:38 +01:00
Darrick J. Wong fb8ee907c1 xfs: prevent UAF in xfs_log_item_in_current_chkpt
commit f8d92a66e8 upstream.

[ Continue to interpret xfs_log_item->li_seq as an LSN rather than a CIL sequence
  number. ]

While I was running with KASAN and lockdep enabled, I stumbled upon an
KASAN report about a UAF to a freed CIL checkpoint.  Looking at the
comment for xfs_log_item_in_current_chkpt, it seems pretty obvious to me
that the original patch to xfs_defer_finish_noroll should have done
something to lock the CIL to prevent it from switching the CIL contexts
while the predicate runs.

For upper level code that needs to know if a given log item is new
enough not to need relogging, add a new wrapper that takes the CIL
context lock long enough to sample the current CIL context.  This is
kind of racy in that the CIL can switch the contexts immediately after
sampling, but that's ok because the consequence is that the defer ops
code is a little slow to relog items.

 ==================================================================
 BUG: KASAN: use-after-free in xfs_log_item_in_current_chkpt+0x139/0x160 [xfs]
 Read of size 8 at addr ffff88804ea5f608 by task fsstress/527999

 CPU: 1 PID: 527999 Comm: fsstress Tainted: G      D      5.16.0-rc4-xfsx #rc4
 Call Trace:
  <TASK>
  dump_stack_lvl+0x45/0x59
  print_address_description.constprop.0+0x1f/0x140
  kasan_report.cold+0x83/0xdf
  xfs_log_item_in_current_chkpt+0x139/0x160
  xfs_defer_finish_noroll+0x3bb/0x1e30
  __xfs_trans_commit+0x6c8/0xcf0
  xfs_reflink_remap_extent+0x66f/0x10e0
  xfs_reflink_remap_blocks+0x2dd/0xa90
  xfs_file_remap_range+0x27b/0xc30
  vfs_dedupe_file_range_one+0x368/0x420
  vfs_dedupe_file_range+0x37c/0x5d0
  do_vfs_ioctl+0x308/0x1260
  __x64_sys_ioctl+0xa1/0x170
  do_syscall_64+0x35/0x80
  entry_SYSCALL_64_after_hwframe+0x44/0xae
 RIP: 0033:0x7f2c71a2950b
 Code: 0f 1e fa 48 8b 05 85 39 0d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff
ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01
f0 ff ff 73 01 c3 48 8b 0d 55 39 0d 00 f7 d8 64 89 01 48
 RSP: 002b:00007ffe8c0e03c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
 RAX: ffffffffffffffda RBX: 00005600862a8740 RCX: 00007f2c71a2950b
 RDX: 00005600862a7be0 RSI: 00000000c0189436 RDI: 0000000000000004
 RBP: 000000000000000b R08: 0000000000000027 R09: 0000000000000003
 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000005a
 R13: 00005600862804a8 R14: 0000000000016000 R15: 00005600862a8a20
  </TASK>

 Allocated by task 464064:
  kasan_save_stack+0x1e/0x50
  __kasan_kmalloc+0x81/0xa0
  kmem_alloc+0xcd/0x2c0 [xfs]
  xlog_cil_ctx_alloc+0x17/0x1e0 [xfs]
  xlog_cil_push_work+0x141/0x13d0 [xfs]
  process_one_work+0x7f6/0x1380
  worker_thread+0x59d/0x1040
  kthread+0x3b0/0x490
  ret_from_fork+0x1f/0x30

 Freed by task 51:
  kasan_save_stack+0x1e/0x50
  kasan_set_track+0x21/0x30
  kasan_set_free_info+0x20/0x30
  __kasan_slab_free+0xed/0x130
  slab_free_freelist_hook+0x7f/0x160
  kfree+0xde/0x340
  xlog_cil_committed+0xbfd/0xfe0 [xfs]
  xlog_cil_process_committed+0x103/0x1c0 [xfs]
  xlog_state_do_callback+0x45d/0xbd0 [xfs]
  xlog_ioend_work+0x116/0x1c0 [xfs]
  process_one_work+0x7f6/0x1380
  worker_thread+0x59d/0x1040
  kthread+0x3b0/0x490
  ret_from_fork+0x1f/0x30

 Last potentially related work creation:
  kasan_save_stack+0x1e/0x50
  __kasan_record_aux_stack+0xb7/0xc0
  insert_work+0x48/0x2e0
  __queue_work+0x4e7/0xda0
  queue_work_on+0x69/0x80
  xlog_cil_push_now.isra.0+0x16b/0x210 [xfs]
  xlog_cil_force_seq+0x1b7/0x850 [xfs]
  xfs_log_force_seq+0x1c7/0x670 [xfs]
  xfs_file_fsync+0x7c1/0xa60 [xfs]
  __x64_sys_fsync+0x52/0x80
  do_syscall_64+0x35/0x80
  entry_SYSCALL_64_after_hwframe+0x44/0xae

 The buggy address belongs to the object at ffff88804ea5f600
  which belongs to the cache kmalloc-256 of size 256
 The buggy address is located 8 bytes inside of
  256-byte region [ffff88804ea5f600, ffff88804ea5f700)
 The buggy address belongs to the page:
 page:ffffea00013a9780 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88804ea5ea00 pfn:0x4ea5e
 head:ffffea00013a9780 order:1 compound_mapcount:0
 flags: 0x4fff80000010200(slab|head|node=1|zone=1|lastcpupid=0xfff)
 raw: 04fff80000010200 ffffea0001245908 ffffea00011bd388 ffff888004c42b40
 raw: ffff88804ea5ea00 0000000000100009 00000001ffffffff 0000000000000000
 page dumped because: kasan: bad access detected

 Memory state around the buggy address:
  ffff88804ea5f500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
  ffff88804ea5f580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 >ffff88804ea5f600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                       ^
  ffff88804ea5f680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff88804ea5f700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ==================================================================

Fixes: 4e919af782 ("xfs: periodically relog deferred intent items")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:38 +01:00
Darrick J. Wong 7c07806ab0 xfs: fix the forward progress assertion in xfs_iwalk_run_callbacks
commit a5336d6bb2 upstream.

In commit 27c14b5daa we started tracking the last inode seen during an
inode walk to avoid infinite loops if a corrupt inobt record happens to
have a lower ir_startino than the record preceeding it.  Unfortunately,
the assertion trips over the case where there are completely empty inobt
records (which can happen quite easily on 64k page filesystems) because
we advance the tracking cursor without actually putting the empty record
into the processing buffer.  Fix the assert to allow for this case.

Reported-by: zlang@redhat.com
Fixes: 27c14b5daa ("xfs: ensure inobt record walks always make forward progress")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Zorro Lang <zlang@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:38 +01:00
Darrick J. Wong 313699d505 xfs: ensure inobt record walks always make forward progress
commit 27c14b5daa upstream.

[ In xfs_iwalk_ag(), Replace a call to XFS_IS_CORRUPT() with a call to
  ASSERT() ]

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: a211432c27 ("xfs: create simplified inode walk function")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:38 +01:00
Darrick J. Wong 7f9309a9f5 xfs: fix missing CoW blocks writeback conversion retry
commit c2f09217a4 upstream.

[ Set xfs_writepage_ctx->fork to XFS_DATA_FORK since 5.4.y tracks current
  extent's fork in this variable ]

In commit 7588cbeec6, we tried to fix a race stemming from the lack of
coordination between higher level code that wants to allocate and remap
CoW fork extents into the data fork.  Christoph cites as examples the
always_cow mode, and a directio write completion racing with writeback.

According to the comments before the goto retry, we want to restart the
lookup to catch the extent in the data fork, but we don't actually reset
whichfork or cow_fsb, which means the second try executes using stale
information.  Up until now I think we've gotten lucky that either
there's something left in the CoW fork to cause cow_fsb to be reset, or
either data/cow fork sequence numbers have advanced enough to force a
fresh lookup from the data fork.  However, if we reach the retry with an
empty stable CoW fork and a stable data fork, neither of those things
happens.  The retry foolishly re-calls xfs_convert_blocks on the CoW
fork which fails again.  This time, we toss the write.

I've recently been working on extending reflink to the realtime device.
When the realtime extent size is larger than a single block, we have to
force the page cache to CoW the entire rt extent if a write (or
fallocate) are not aligned with the rt extent size.  The strategy I've
chosen to deal with this is derived from Dave's blocksize > pagesize
series: dirtying around the write range, and ensuring that writeback
always starts mapping on an rt extent boundary.  This has brought this
race front and center, since generic/522 blows up immediately.

However, I'm pretty sure this is a bug outright, independent of that.

Fixes: 7588cbeec6 ("xfs: retry COW fork delalloc conversion when no extent was found")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:38 +01:00
Darrick J. Wong 6246b3a18f xfs: only relog deferred intent items if free space in the log gets low
commit 74f4d6a1e0 upstream.

Now that we have the ability to ask the log how far the tail needs to be
pushed to maintain its free space targets, augment the decision to relog
an intent item so that we only do it if the log has hit the 75% full
threshold.  There's no point in relogging an intent into the same
checkpoint, and there's no need to relog if there's plenty of free space
in the log.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:37 +01:00
Darrick J. Wong 09d6181447 xfs: expose the log push threshold
commit ed1575daf7 upstream.

Separate the computation of the log push threshold and the push logic in
xlog_grant_push_ail.  This enables higher level code to determine (for
example) that it is holding on to a logged intent item and the log is so
busy that it is more than 75% full.  In that case, it would be desirable
to move the log item towards the head to release the tail, which we will
cover in the next patch.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:37 +01:00
Darrick J. Wong 5d711e4136 xfs: periodically relog deferred intent items
commit 4e919af782 upstream.

[ Modify xfs_{bmap|extfree|refcount|rmap}_item.c to fix merge conflicts ]

There's a subtle design flaw in the deferred log item code that can lead
to pinning the log tail.  Taking up the defer ops chain examples from
the previous commit, we can get trapped in sequences like this:

Caller hands us a transaction t0 with D0-D3 attached.  The defer ops
chain will look like the following if the transaction rolls succeed:

t1: D0(t0), D1(t0), D2(t0), D3(t0)
t2: d4(t1), d5(t1), D1(t0), D2(t0), D3(t0)
t3: d5(t1), D1(t0), D2(t0), D3(t0)
...
t9: d9(t7), D3(t0)
t10: D3(t0)
t11: d10(t10), d11(t10)
t12: d11(t10)

In transaction 9, we finish d9 and try to roll to t10 while holding onto
an intent item for D3 that we logged in t0.

The previous commit changed the order in which we place new defer ops in
the defer ops processing chain to reduce the maximum chain length.  Now
make xfs_defer_finish_noroll capable of relogging the entire chain
periodically so that we can always move the log tail forward.  Most
chains will never get relogged, except for operations that generate very
long chains (large extents containing many blocks with different sharing
levels) or are on filesystems with small logs and a lot of ongoing
metadata updates.

Callers are now required to ensure that the transaction reservation is
large enough to handle logging done items and new intent items for the
maximum possible chain length.  Most callers are careful to keep the
chain lengths low, so the overhead should be minimal.

The decision to relog an intent item is made based on whether the intent
was logged in a previous checkpoint, since there's no point in relogging
an intent into the same checkpoint.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:37 +01:00
Darrick J. Wong 870e7d7108 xfs: change the order in which child and parent defer ops are finished
commit 27dada070d upstream.

The defer ops code has been finishing items in the wrong order -- if a
top level defer op creates items A and B, and finishing item A creates
more defer ops A1 and A2, we'll put the new items on the end of the
chain and process them in the order A B A1 A2.  This is kind of weird,
since it's convenient for programmers to be able to think of A and B as
an ordered sequence where all the sub-tasks for A must finish before we
move on to B, e.g. A A1 A2 D.

Right now, our log intent items are not so complex that this matters,
but this will become important for the atomic extent swapping patchset.
In order to maintain correct reference counting of extents, we have to
unmap and remap extents in that order, and we want to complete that work
before moving on to the next range that the user wants to swap.  This
patch fixes defer ops to satsify that requirement.

The primary symptom of the incorrect order was noticed in an early
performance analysis of the atomic extent swap code.  An astonishingly
large number of deferred work items accumulated when userspace requested
an atomic update of two very fragmented files.  The cause of this was
traced to the same ordering bug in the inner loop of
xfs_defer_finish_noroll.

If the ->finish_item method of a deferred operation queues new deferred
operations, those new deferred ops are appended to the tail of the
pending work list.  To illustrate, say that a caller creates a
transaction t0 with four deferred operations D0-D3.  The first thing
defer ops does is roll the transaction to t1, leaving us with:

t1: D0(t0), D1(t0), D2(t0), D3(t0)

Let's say that finishing each of D0-D3 will create two new deferred ops.
After finish D0 and roll, we'll have the following chain:

t2: D1(t0), D2(t0), D3(t0), d4(t1), d5(t1)

d4 and d5 were logged to t1.  Notice that while we're about to start
work on D1, we haven't actually completed all the work implied by D0
being finished.  So far we've been careful (or lucky) to structure the
dfops callers such that D1 doesn't depend on d4 or d5 being finished,
but this is a potential logic bomb.

There's a second problem lurking.  Let's see what happens as we finish
D1-D3:

t3: D2(t0), D3(t0), d4(t1), d5(t1), d6(t2), d7(t2)
t4: D3(t0), d4(t1), d5(t1), d6(t2), d7(t2), d8(t3), d9(t3)
t5: d4(t1), d5(t1), d6(t2), d7(t2), d8(t3), d9(t3), d10(t4), d11(t4)

Let's say that d4-d11 are simple work items that don't queue any other
operations, which means that we can complete each d4 and roll to t6:

t6: d5(t1), d6(t2), d7(t2), d8(t3), d9(t3), d10(t4), d11(t4)
t7: d6(t2), d7(t2), d8(t3), d9(t3), d10(t4), d11(t4)
...
t11: d10(t4), d11(t4)
t12: d11(t4)
<done>

When we try to roll to transaction #12, we're holding defer op d11,
which we logged way back in t4.  This means that the tail of the log is
pinned at t4.  If the log is very small or there are a lot of other
threads updating metadata, this means that we might have wrapped the log
and cannot get roll to t11 because there isn't enough space left before
we'd run into t4.

Let's shift back to the original failure.  I mentioned before that I
discovered this flaw while developing the atomic file update code.  In
that scenario, we have a defer op (D0) that finds a range of file blocks
to remap, creates a handful of new defer ops to do that, and then asks
to be continued with however much work remains.

So, D0 is the original swapext deferred op.  The first thing defer ops
does is rolls to t1:

t1: D0(t0)

We try to finish D0, logging d1 and d2 in the process, but can't get all
the work done.  We log a done item and a new intent item for the work
that D0 still has to do, and roll to t2:

t2: D0'(t1), d1(t1), d2(t1)

We roll and try to finish D0', but still can't get all the work done, so
we log a done item and a new intent item for it, requeue D0 a second
time, and roll to t3:

t3: D0''(t2), d1(t1), d2(t1), d3(t2), d4(t2)

If it takes 48 more rolls to complete D0, then we'll finally dispense
with D0 in t50:

t50: D<fifty primes>(t49), d1(t1), ..., d102(t50)

We then try to roll again to get a chain like this:

t51: d1(t1), d2(t1), ..., d101(t50), d102(t50)
...
t152: d102(t50)
<done>

Notice that in rolling to transaction #51, we're holding on to a log
intent item for d1 that was logged in transaction #1.  This means that
the tail of the log is pinned at t1.  If the log is very small or there
are a lot of other threads updating metadata, this means that we might
have wrapped the log and cannot roll to t51 because there isn't enough
space left before we'd run into t1.  This is of course problem #2 again.

But notice the third problem with this scenario: we have 102 defer ops
tied to this transaction!  Each of these items are backed by pinned
kernel memory, which means that we risk OOM if the chains get too long.

Yikes.  Problem #1 is a subtle logic bomb that could hit someone in the
future; problem #2 applies (rarely) to the current upstream, and problem

This is not how incremental deferred operations were supposed to work.
The dfops design of logging in the same transaction an intent-done item
and a new intent item for the work remaining was to make it so that we
only have to juggle enough deferred work items to finish that one small
piece of work.  Deferred log item recovery will find that first
unfinished work item and restart it, no matter how many other intent
items might follow it in the log.  Therefore, it's ok to put the new
intents at the start of the dfops chain.

For the first example, the chains look like this:

t2: d4(t1), d5(t1), D1(t0), D2(t0), D3(t0)
t3: d5(t1), D1(t0), D2(t0), D3(t0)
...
t9: d9(t7), D3(t0)
t10: D3(t0)
t11: d10(t10), d11(t10)
t12: d11(t10)

For the second example, the chains look like this:

t1: D0(t0)
t2: d1(t1), d2(t1), D0'(t1)
t3: d2(t1), D0'(t1)
t4: D0'(t1)
t5: d1(t4), d2(t4), D0''(t4)
...
t148: D0<50 primes>(t147)
t149: d101(t148), d102(t148)
t150: d102(t148)
<done>

This actually sucks more for pinning the log tail (we try to roll to t10
while holding an intent item that was logged in t1) but we've solved
problem #1.  We've also reduced the maximum chain length from:

    sum(all the new items) + nr_original_items

to:

    max(new items that each original item creates) + nr_original_items

This solves problem #3 by sharply reducing the number of defer ops that
can be attached to a transaction at any given time.  The change makes
the problem of log tail pinning worse, but is improvement we need to
solve problem #2.  Actually solving #2, however, is left to the next
patch.

Note that a subsequent analysis of some hard-to-trigger reflink and COW
livelocks on extremely fragmented filesystems (or systems running a lot
of IO threads) showed the same symptoms -- uncomfortably large numbers
of incore deferred work items and occasional stalls in the transaction
grant code while waiting for log reservations.  I think this patch and
the next one will also solve these problems.

As originally written, the code used list_splice_tail_init instead of
list_splice_init, so change that, and leave a short comment explaining
our actions.

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: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:37 +01:00
Darrick J. Wong f5af1d5c2d xfs: fix an incore inode UAF in xfs_bui_recover
commit ff4ab5e02a upstream.

In xfs_bui_item_recover, there exists a use-after-free bug with regards
to the inode that is involved in the bmap replay operation.  If the
mapping operation does not complete, we call xfs_bmap_unmap_extent to
create a deferred op to finish the unmapping work, and we retain a
pointer to the incore inode.

Unfortunately, the very next thing we do is commit the transaction and
drop the inode.  If reclaim tears down the inode before we try to finish
the defer ops, we dereference garbage and blow up.  Therefore, create a
way to join inodes to the defer ops freezer so that we can maintain the
xfs_inode reference until we're done with the inode.

Note: This imposes the requirement that there be enough memory to keep
every incore inode in memory throughout recovery.

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: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:37 +01:00
Darrick J. Wong efcdc2e70e xfs: clean up xfs_bui_item_recover iget/trans_alloc/ilock ordering
commit 64a3f3315b upstream.

In most places in XFS, we have a specific order in which we gather
resources: grab the inode, allocate a transaction, then lock the inode.
xfs_bui_item_recover doesn't do it in that order, so fix it to be more
consistent.  This also makes the error bailout code a bit less weird.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:37 +01:00
Darrick J. Wong abad319dee xfs: clean up bmap intent item recovery checking
commit 919522e89f upstream.

The bmap intent item checking code in xfs_bui_item_recover is spread all
over the function.  We should check the recovered log item at the top
before we allocate any resources or do anything else, so do that.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:37 +01:00
Darrick J. Wong 6601531db8 xfs: xfs_defer_capture should absorb remaining transaction reservation
commit 929b92f640 upstream.

When xfs_defer_capture extracts the deferred ops and transaction state
from a transaction, it should record the transaction reservation type
from the old transaction so that when we continue the dfops chain, we
still use the same reservation parameters.

Doing this means that the log item recovery functions get to determine
the transaction reservation instead of abusing tr_itruncate in yet
another part of xfs.

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: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:37 +01:00
Darrick J. Wong 411b14e68c xfs: xfs_defer_capture should absorb remaining block reservations
commit 4f9a60c480 upstream.

When xfs_defer_capture extracts the deferred ops and transaction state
from a transaction, it should record the remaining block reservations so
that when we continue the dfops chain, we can reserve the same number of
blocks to use.  We capture the reservations for both data and realtime
volumes.

This adds the requirement that every log intent item recovery function
must be careful to reserve enough blocks to handle both itself and all
defer ops that it can queue.  On the other hand, this enables us to do
away with the handwaving block estimation nonsense that was going on in
xlog_finish_defer_ops.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:36 +01:00
Darrick J. Wong 3324249e6e xfs: proper replay of deferred ops queued during log recovery
commit e6fff81e48 upstream.

When we replay unfinished intent items that have been recovered from the
log, it's possible that the replay will cause the creation of more
deferred work items.  As outlined in commit 509955823c ("xfs: log
recovery should replay deferred ops in order"), later work items have an
implicit ordering dependency on earlier work items.  Therefore, recovery
must replay the items (both recovered and created) in the same order
that they would have been during normal operation.

For log recovery, we enforce this ordering by using an empty transaction
to collect deferred ops that get created in the process of recovering a
log intent item to prevent them from being committed before the rest of
the recovered intent items.  After we finish committing all the
recovered log items, we allocate a transaction with an enormous block
reservation, splice our huge list of created deferred ops into that
transaction, and commit it, thereby finishing all those ops.

This is /really/ hokey -- it's the one place in XFS where we allow
nested transactions; the splicing of the defer ops list is is inelegant
and has to be done twice per recovery function; and the broken way we
handle inode pointers and block reservations cause subtle use-after-free
and allocator problems that will be fixed by this patch and the two
patches after it.

Therefore, replace the hokey empty transaction with a structure designed
to capture each chain of deferred ops that are created as part of
recovering a single unfinished log intent.  Finally, refactor the loop
that replays those chains to do so using one transaction per chain.

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: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:36 +01:00
Dave Chinner 1c89c04305 xfs: fix finobt btree block recovery ordering
commit 671459676a upstream.

[ In 5.4.y, xlog_recover_get_buf_lsn() is defined inside
  fs/xfs/xfs_log_recover.c ]

Nathan popped up on #xfs and pointed out that we fail to handle
finobt btree blocks in xlog_recover_get_buf_lsn(). This means they
always fall through the entire magic number matching code to "recover
immediately". Whilst most of the time this is the correct behaviour,
occasionally it will be incorrect and could potentially overwrite
more recent metadata because we don't check the LSN in the on disk
metadata at all.

This bug has been present since the finobt was first introduced, and
is a potential cause of the occasional xfs_iget_check_free_state()
failures we see that indicate that the inode btree state does not
match the on disk inode state.

Fixes: aafc3c2465 ("xfs: support the XFS_BTNUM_FINOBT free inode btree type")
Reported-by: Nathan Scott <nathans@redhat.com>
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>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:36 +01:00
Darrick J. Wong 6678b2787b xfs: log new intent items created as part of finishing recovered intent items
commit 93293bcbde upstream.

[Slightly edit fs/xfs/xfs_bmap_item.c & fs/xfs/xfs_refcount_item.c to resolve
merge conflicts]

During a code inspection, I found a serious bug in the log intent item
recovery code when an intent item cannot complete all the work and
decides to requeue itself to get that done.  When this happens, the
item recovery creates a new incore deferred op representing the
remaining work and attaches it to the transaction that it allocated.  At
the end of _item_recover, it moves the entire chain of deferred ops to
the dummy parent_tp that xlog_recover_process_intents passed to it, but
fail to log a new intent item for the remaining work before committing
the transaction for the single unit of work.

xlog_finish_defer_ops logs those new intent items once recovery has
finished dealing with the intent items that it recovered, but this isn't
sufficient.  If the log is forced to disk after a recovered log item
decides to requeue itself and the system goes down before we call
xlog_finish_defer_ops, the second log recovery will never see the new
intent item and therefore has no idea that there was more work to do.
It will finish recovery leaving the filesystem in a corrupted state.

The same logic applies to /any/ deferred ops added during intent item
recovery, not just the one handling the remaining work.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:36 +01:00
Christoph Hellwig 562da8e704 xfs: refactor xfs_defer_finish_noroll
commit bb47d79750 upstream.

Split out a helper that operates on a single xfs_defer_pending structure
to untangle the code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
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>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:36 +01:00
Christoph Hellwig 42a2406f90 xfs: turn dfp_intent into a xfs_log_item
commit 13a8333339 upstream.

All defer op instance place their own extension of the log item into
the dfp_intent field.  Replace that with a xfs_log_item to improve type
safety and make the code easier to follow.

Signed-off-by: Christoph Hellwig <hch@lst.de>
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>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:36 +01:00
Christoph Hellwig e11f1516fc xfs: merge the ->diff_items defer op into ->create_intent
commit d367a868e4 upstream.

This avoids a per-item indirect call, and also simplifies the interface
a bit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
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>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:36 +01:00
Christoph Hellwig e84096edf8 xfs: merge the ->log_item defer op into ->create_intent
commit c1f09188e8 upstream.

These are aways called together, and my merging them we reduce the amount
of indirect calls, improve type safety and in general clean up the code
a bit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
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>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:36 +01:00
Christoph Hellwig 64b21eaa33 xfs: factor out a xfs_defer_create_intent helper
commit e046e94948 upstream.

Create a helper that encapsulates the whole logic to create a defer
intent.  This reorders some of the work that was done, but none of
that has an affect on the operation as only fields that don't directly
interact are affected.

Signed-off-by: Christoph Hellwig <hch@lst.de>
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>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:35 +01:00
Christoph Hellwig d24633f3c2 xfs: remove the xfs_inode_log_item_t typedef
commit fd9cbe5121 upstream.

Signed-off-by: Christoph Hellwig <hch@lst.de>
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>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:35 +01:00
Christoph Hellwig e0373eeaaa xfs: remove the xfs_efd_log_item_t typedef
commit c84e819090 upstream.

Signed-off-by: Christoph Hellwig <hch@lst.de>
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>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:35 +01:00
Christoph Hellwig 94e0639992 xfs: remove the xfs_efi_log_item_t typedef
commit 82ff450b2d upstream.

Signed-off-by: Christoph Hellwig <hch@lst.de>
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>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:35 +01:00
Brian Foster 45a841719f xfs: drain the buf delwri queue before xfsaild idles
commit f376b45e86 upstream.

xfsaild is racy with respect to transaction abort and shutdown in
that the task can idle or exit with an empty AIL but buffers still
on the delwri queue. This was partly addressed by cancelling the
delwri queue before the task exits to prevent memory leaks, but it's
also possible for xfsaild to empty and idle with buffers on the
delwri queue. For example, a transaction that pins a buffer that
also happens to sit on the AIL delwri queue will explicitly remove
the associated log item from the AIL if the transaction aborts. The
side effect of this is an unmount hang in xfs_wait_buftarg() as the
associated buffers remain held by the delwri queue indefinitely.
This is reproduced on repeated runs of generic/531 with an fs format
(-mrmapbt=1 -bsize=1k) that happens to also reproduce transaction
aborts.

Update xfsaild to not idle until both the AIL and associated delwri
queue are empty and update the push code to continue delwri queue
submission attempts even when the AIL is empty. This allows the AIL
to eventually release aborted buffers stranded on the delwri queue
when they are unlocked by the associated transaction. This should
have no significant effect on normal runtime behavior because the
xfsaild currently idles only when the AIL is empty and in practice
the AIL is rarely empty with a populated delwri queue. The items
must be AIL resident to land in the queue in the first place and
generally aren't removed until writeback completes.

Note that the pre-existing delwri queue cancel logic in the exit
path is retained because task stop is external, could technically
come at any point, and xfsaild is still responsible to release its
buffer references before it exits.

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>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-25 17:42:03 +01:00
Eric Sandeen e107e953d2 xfs: preserve inode versioning across remounts
commit 4750a171c3 upstream.

[ For 5.4.y, SB_I_VERSION should be set in xfs_fs_remount() ]

The MS_I_VERSION mount flag is exposed via the VFS, as documented
in the mount manpages etc; see the iversion and noiversion mount
options in mount(8).

As a result, mount -o remount looks for this option in /proc/mounts
and will only send the I_VERSION flag back in during remount it it
is present.  Since it's not there, a remount will /remove/ the
I_VERSION flag at the vfs level, and iversion functionality is lost.

xfs v5 superblocks intend to always have i_version enabled; it is
set as a default at mount time, but is lost during remount for the
reasons above.

The generic fix would be to expose this documented option in
/proc/mounts, but since that was rejected, fix it up again in the
xfs remount path instead, so that at least xfs won't suffer from
this misbehavior.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-25 17:42:03 +01:00
Dave Chinner 7d57979052 xfs: use MMAPLOCK around filemap_map_pages()
commit cd647d5651 upstream.

The page faultround path ->map_pages is implemented in XFS via
filemap_map_pages(). This function checks that pages found in page
cache lookups have not raced with truncate based invalidation by
checking page->mapping is correct and page->index is within EOF.

However, we've known for a long time that this is not sufficient to
protect against races with invalidations done by operations that do
not change EOF. e.g. hole punching and other fallocate() based
direct extent manipulations. The way we protect against these
races is we wrap the page fault operations in a XFS_MMAPLOCK_SHARED
lock so they serialise against fallocate and truncate before calling
into the filemap function that processes the fault.

Do the same for XFS's ->map_pages implementation to close this
potential data corruption issue.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.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>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-25 17:42:03 +01:00
Darrick J. Wong 8b27e684a6 xfs: redesign the reflink remap loop to fix blkres depletion crash
commit 00fd1d56dd upstream.

The existing reflink remapping loop has some structural problems that
need addressing:

The biggest problem is that we create one transaction for each extent in
the source file without accounting for the number of mappings there are
for the same range in the destination file.  In other words, we don't
know the number of remap operations that will be necessary and we
therefore cannot guess the block reservation required.  On highly
fragmented filesystems (e.g. ones with active dedupe) we guess wrong,
run out of block reservation, and fail.

The second problem is that we don't actually use the bmap intents to
their full potential -- instead of calling bunmapi directly and having
to deal with its backwards operation, we could call the deferred ops
xfs_bmap_unmap_extent and xfs_refcount_decrease_extent instead.  This
makes the frontend loop much simpler.

Solve all of these problems by refactoring the remapping loops so that
we only perform one remapping operation per transaction, and each
operation only tries to remap a single extent from source to dest.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reported-by: Edwin Török <edwin@etorok.net>
Tested-by: Edwin Török <edwin@etorok.net>
Acked-by: Darrick J. Wong <djwong@kernel.org>
[backported to 5.4.y - Tested-by above does not refer to the backport]
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-25 17:42:03 +01:00
Darrick J. Wong ece1eb9957 xfs: rename xfs_bmap_is_real_extent to is_written_extent
commit 877f58f536 upstream.

[ Slightly modify fs/xfs/libxfs/xfs_rtbitmap.c & fs/xfs/xfs_reflink.c to
  resolve merge conflict ]

The name of this predicate is a little misleading -- it decides if the
extent mapping is allocated and written.  Change the name to be more
direct, as we're going to add a new predicate in the next patch.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-25 17:42:03 +01:00