Hi again, Even with the fix to the per-AG reservation code applied, I still see periodic failures in xfs/168 if I run with ./check -I 60. This is what's at the bottom of 168.full: [EXPERIMENTAL] try to shrink unused space 131446, old size is 131532 meta-data=/dev/sdf isize=512 agcount=2, agsize=129280 blks = sectsz=512 attr=2, projid32bit=1 = crc=1 finobt=1, sparse=1, rmapbt=0 = reflink=0 bigtime=1 inobtcount=1 data = bsize=4096 blocks=131532, imaxpct=25 = sunit=0 swidth=0 blks naming =version 2 bsize=4096 ascii-ci=0, ftype=1 log =internal log bsize=4096 blocks=1344, version=2 = sectsz=512 sunit=0 blks, lazy-count=1 realtime =/dev/sdd extsz=4096 blocks=2579968, rtextents=2579968 data blocks changed from 131532 to 131446 Phase 1 - find and verify superblock... Only two AGs detected and they do not match - cannot validate filesystem geometry. Use the -o force_geometry option to proceed. xfs_repair failed with shrinking 131446 The kernel log contains this: [ 2017.388598] XFS (sdf): Internal error !ino_ok at line 205 of file fs/xfs/libxfs/xfs_dir2.c. Caller xfs_dir_ino_validate+0x4b/0xa0 [xfs] [ 2017.392045] CPU: 3 PID: 49956 Comm: xfsaild/sdf Tainted: G O 5.13.0-rc3-xfsx #rc3 [ 2017.393165] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014 [ 2017.394166] Call Trace: [ 2017.394488] dump_stack+0x64/0x7c [ 2017.395117] xfs_corruption_error+0x85/0x90 [xfs] [ 2017.396362] ? xfs_dir_ino_validate+0x4b/0xa0 [xfs] [ 2017.397599] xfs_dir_ino_validate+0x75/0xa0 [xfs] [ 2017.398506] ? xfs_dir_ino_validate+0x4b/0xa0 [xfs] [ 2017.399655] xfs_dir2_sf_verify+0x16d/0x2d0 [xfs] [ 2017.400731] xfs_ifork_verify_local_data+0x33/0x60 [xfs] [ 2017.402019] xfs_iflush_cluster+0x67f/0x8f0 [xfs] [ 2017.403163] xfs_inode_item_push+0xa8/0x140 [xfs] [ 2017.404203] xfsaild+0x42c/0xc50 [xfs] [ 2017.405106] ? xfs_trans_ail_cursor_first+0x80/0x80 [xfs] [ 2017.406306] kthread+0x14b/0x170 [ 2017.406929] ? __kthread_bind_mask+0x60/0x60 [ 2017.407638] ret_from_fork+0x1f/0x30 [ 2017.408323] XFS (sdf): Corruption detected. Unmount and run xfs_repair [ 2017.409467] XFS (sdf): Invalid inode number 0x104380 [ 2017.410301] XFS (sdf): Metadata corruption detected at xfs_dir2_sf_verify+0x268/0x2d0 [xfs], inode 0x4fb6 data fork [ 2017.412095] XFS (sdf): Unmount and run xfs_repair [ 2017.412675] XFS (sdf): First 72 bytes of corrupted metadata buffer: [ 2017.413393] 00000000: 06 00 00 10 42 60 03 00 60 63 37 61 03 00 10 43 ....B`..`c7a...C [ 2017.414286] 00000010: 80 03 00 70 64 38 39 02 00 00 4f bd 03 00 80 72 ...pd89...O....r [ 2017.415390] 00000020: 38 65 01 00 10 43 32 03 00 90 72 61 62 01 00 00 8e...C2...rab... [ 2017.416633] 00000030: 4e 3f 03 00 a0 66 62 34 01 00 00 51 1e 03 00 b0 N?...fb4...Q.... [ 2017.417733] 00000040: 63 66 61 03 00 00 50 9e cfa...P. [ 2017.418810] XFS (sdf): metadata I/O error in "xfs_buf_ioend+0x219/0x520 [xfs]" at daddr 0x4fa0 len 32 error 5 [ 2017.420397] XFS (sdf): xfs_do_force_shutdown(0x8) called from line 2798 of file fs/xfs/xfs_inode.c. Return address = ffffffffa03a6018 [ 2017.422171] XFS (sdf): Corruption of in-memory data detected. Shutting down filesystem [ 2017.423348] XFS (sdf): Please unmount the filesystem and rectify the problem(s) [ 2017.631561] XFS (sda): Unmounting Filesystem At first glance this /looks/ like we might have shrunk the filesystem too far, after which the shortform directory verifier tripped, which caused a shutdown. Inode 0x104380 is very close to the end of the filesystem. I altered xfs/168 to spit out metadumps and captured one here: https://djwong.org/docs/168.iloop.131446.md.xz I'll keep looking, but on the off chance this rings a bell for anyone. Wait, something just rang a bell for me. I was looking through Allison's xattrs patchset and read the comment in xfs_attr_rmtval_set about how it has to perform a "user data" allocation for the remote value blocks because we don't log attr value blocks and therefore cannot overwrite blocks which have recently been freed but their transactions are not yet committed to disk. Doesn't shrink have to ensure that the log cannot contain any further updates for the blocks it wants to remove from the filesystem? In other words, should xfs_ag_shrink_space be setting XFS_ALLOC_USERDATA so that the allocator will make us wait for the EOFS blocks to free up if they're busy? --D