From: "Darrick J. Wong" djwong@kernel.org
commit c0e37f07d2bd3c1ee3fb5a650da7d8673557ed16 upstream.
Overall, this function tries to find and invalidate all buffers for a given extent of space on the data device. The inner for loop in this function tries to find all xfs_bufs for a given daddr. The lengths of all possible cached buffers range from 1 fsblock to the largest needed to contain a 64k xattr value (~17fsb). The scan is capped to avoid looking at anything buffer going past the given extent.
Unfortunately, the loop continuation test is wrong -- max_fsbs is the largest size we want to scan, not one past that. Put another way, this loop is actually 1-indexed, not 0-indexed. Therefore, the continuation test should use <=, not <.
As a result, online repairs of btree blocks fails to stale any buffers for btrees that are being torn down, which causes later assertions in the buffer cache when another thread creates a different-sized buffer. This happens in xfs/709 when allocating an inode cluster buffer:
------------[ cut here ]------------ WARNING: CPU: 0 PID: 3346128 at fs/xfs/xfs_message.c:104 assfail+0x3a/0x40 [xfs] CPU: 0 PID: 3346128 Comm: fsstress Not tainted 6.7.0-rc4-djwx #rc4 RIP: 0010:assfail+0x3a/0x40 [xfs] Call Trace: <TASK> _xfs_buf_obj_cmp+0x4a/0x50 xfs_buf_get_map+0x191/0xba0 xfs_trans_get_buf_map+0x136/0x280 xfs_ialloc_inode_init+0x186/0x340 xfs_ialloc_ag_alloc+0x254/0x720 xfs_dialloc+0x21f/0x870 xfs_create_tmpfile+0x1a9/0x2f0 xfs_rename+0x369/0xfd0 xfs_vn_rename+0xfa/0x170 vfs_rename+0x5fb/0xc30 do_renameat2+0x52d/0x6e0 __x64_sys_renameat2+0x4b/0x60 do_syscall_64+0x3b/0xe0 entry_SYSCALL_64_after_hwframe+0x46/0x4e
A later refactoring patch in the online repair series fixed this by accident, which is why I didn't notice this until I started testing only the patches that are likely to end up in 6.8.
Fixes: 1c7ce115e521 ("xfs: reap large AG metadata extents when possible") Signed-off-by: "Darrick J. Wong" djwong@kernel.org Reviewed-by: Dave Chinner dchinner@redhat.com Signed-off-by: Chandan Babu R chandanbabu@kernel.org Signed-off-by: Catherine Hoang catherine.hoang@oracle.com Acked-by: Darrick J. Wong djwong@kernel.org --- fs/xfs/scrub/reap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/xfs/scrub/reap.c b/fs/xfs/scrub/reap.c index 86a62420e02c..822f5adf7f7c 100644 --- a/fs/xfs/scrub/reap.c +++ b/fs/xfs/scrub/reap.c @@ -247,7 +247,7 @@ xreap_agextent_binval( max_fsbs = min_t(xfs_agblock_t, agbno_next - bno, xfs_attr3_rmt_blocks(mp, XFS_XATTR_SIZE_MAX));
- for (fsbcount = 1; fsbcount < max_fsbs; fsbcount++) { + for (fsbcount = 1; fsbcount <= max_fsbs; fsbcount++) { struct xfs_buf *bp = NULL; xfs_daddr_t daddr; int error;