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01c84d2dc1
I've been seeing regular ASSERT failures in xfstests when running
fsstress based tests over the past month. xfs_getbmap() has been
failing this test:
XFS: Assertion failed: ((iflags & BMV_IF_DELALLOC) != 0) ||
(map[i].br_startblock != DELAYSTARTBLOCK), file: fs/xfs/xfs_bmap.c,
line: 5650
where it is encountering a delayed allocation extent after writing
all the dirty data to disk and then walking the extent map
atomically by holding the XFS_IOLOCK_SHARED to prevent new delayed
allocation extents from being created.
Test 083 on a 512 byte block size filesystem was used to reproduce
the problem, because it only had a 5s run timeand would usually fail
every 3-4 runs. This test is exercising ENOSPC behaviour by running
fsstress on a nearly full filesystem. The following trace extract
shows the final few events on the inode that tripped the assert:
xfs_ilock: flags ILOCK_EXCL caller xfs_setfilesize
xfs_setfilesize: isize 0x180000 disize 0x12d400 offset 0x17e200 count 7680
file size updated to 0x180000 by IO completion
xfs_ilock: flags ILOCK_EXCL caller xfs_iomap_write_delay
xfs_iext_insert: state idx 3 offset 3072 block 4503599627239432 count 1 flag 0 caller xfs_bmap_add_extent_hole_delay
xfs_get_blocks_alloc: size 0x180000 offset 0x180000 count 512 type startoff 0xc00 startblock -1 blockcount 0x1
xfs_ilock: flags ILOCK_EXCL caller __xfs_get_blocks
delalloc write, adding a single block at offset 0x180000
xfs_delalloc_enospc: isize 0x180000 disize 0x180000 offset 0x180200 count 512
ENOSPC trying to allocate a dellalloc block at offset 0x180200
xfs_ilock: flags ILOCK_EXCL caller xfs_iomap_write_delay
xfs_get_blocks_alloc: size 0x180000 offset 0x180200 count 512 type startoff 0xc00 startblock -1 blockcount 0x2
And succeeding on retry after flushing dirty inodes.
xfs_ilock: flags ILOCK_EXCL caller __xfs_get_blocks
xfs_delalloc_enospc: isize 0x180000 disize 0x180000 offset 0x180400 count 512
ENOSPC trying to allocate a dellalloc block at offset 0x180400
xfs_ilock: flags ILOCK_EXCL caller xfs_iomap_write_delay
xfs_delalloc_enospc: isize 0x180000 disize 0x180000 offset 0x180400 count 512
And failing the retry, giving a real ENOSPC error.
xfs_ilock: flags ILOCK_EXCL caller xfs_vm_write_failed
^^^^^^^^^^^^^^^^^^^
The smoking gun - the write being failed and cleaning up delalloc
blocks beyond EOF allocated by the failed write.
xfs_getattr:
xfs_ilock: flags IOLOCK_SHARED caller xfs_getbmap
xfs_ilock: flags ILOCK_SHARED caller xfs_ilock_map_shared
And that's where we died almost immediately afterwards.
xfs_bmapi_read() found delalloc extent beyond current file in memory
file size. Some debug I added to xfs_getbmap() showed the state just
before the assert failure:
ino 0x80e48: off 0xc00, fsb 0xffffffffffffffff, len 0x1, size 0x180000
start_fsb 0x106, end_fsb 0x638
ino flags 0x2 nex 0xd bmvcnt 0x555, len 0x3c58a6f23c0bf1, start 0xc00
ext 0: off 0x1fc, fsb 0x24782, len 0x254
ext 1: off 0x450, fsb 0x40851, len 0x30
ext 2: off 0x480, fsb 0xd99, len 0x1b8
ext 3: off 0x92f, fsb 0x4099a, len 0x3b
ext 4: off 0x96d, fsb 0x41844, len 0x98
ext 5: off 0xbf1, fsb 0x408ab, len 0xf
which shows that we found a single delalloc block beyond EOF (first
line of output) when we were returning the map for a length
somewhere around 10^16 bytes long (second line), and the on-disk
extents showed they didn't go past EOF (last lines).
Further debug added to xfs_vm_write_failed() showed this happened
when punching out delalloc blocks beyond the end of the file after
the failed write:
[ 132.606693] ino 0x80e48: vwf to 0x181000, sze 0x180000
[ 132.609573] start_fsb 0xc01, end_fsb 0xc08
It punched the range 0xc01 -> 0xc08, but the range we really need to
punch is 0xc00 -> 0xc07 (8 blocks from 0xc00) as this testing was
run on a 512 byte block size filesystem (8 blocks per page).
the punch from is 0xc00. So end_fsb is correct, but start_fsb is
wrong as we punch from start_fsb for (end_fsb - start_fsb) blocks.
Hence we are not punching the delalloc block beyond EOF in the case.
The fix is simple - it's a silly off-by-one mistake in calculating
the range. It's especially silly because the macro used to calculate
the start_fsb already takes into account the case where the inode
size is an exact multiple of the filesystem block size...
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
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|---|---|---|
| .. | ||
| Kconfig | ||
| kmem.c | ||
| kmem.h | ||
| Makefile | ||
| mrlock.h | ||
| time.h | ||
| uuid.c | ||
| uuid.h | ||
| xfs.h | ||
| xfs_acl.c | ||
| xfs_acl.h | ||
| xfs_ag.h | ||
| xfs_alloc.c | ||
| xfs_alloc.h | ||
| xfs_alloc_btree.c | ||
| xfs_alloc_btree.h | ||
| xfs_aops.c | ||
| xfs_aops.h | ||
| xfs_attr.c | ||
| xfs_attr.h | ||
| xfs_attr_leaf.c | ||
| xfs_attr_leaf.h | ||
| xfs_attr_sf.h | ||
| xfs_bit.c | ||
| xfs_bit.h | ||
| xfs_bmap.c | ||
| xfs_bmap.h | ||
| xfs_bmap_btree.c | ||
| xfs_bmap_btree.h | ||
| xfs_btree.c | ||
| xfs_btree.h | ||
| xfs_buf.c | ||
| xfs_buf.h | ||
| xfs_buf_item.c | ||
| xfs_buf_item.h | ||
| xfs_da_btree.c | ||
| xfs_da_btree.h | ||
| xfs_dfrag.c | ||
| xfs_dfrag.h | ||
| xfs_dinode.h | ||
| xfs_dir2.c | ||
| xfs_dir2.h | ||
| xfs_dir2_block.c | ||
| xfs_dir2_data.c | ||
| xfs_dir2_format.h | ||
| xfs_dir2_leaf.c | ||
| xfs_dir2_node.c | ||
| xfs_dir2_priv.h | ||
| xfs_dir2_sf.c | ||
| xfs_discard.c | ||
| xfs_discard.h | ||
| xfs_dquot.c | ||
| xfs_dquot.h | ||
| xfs_dquot_item.c | ||
| xfs_dquot_item.h | ||
| xfs_error.c | ||
| xfs_error.h | ||
| xfs_export.c | ||
| xfs_export.h | ||
| xfs_extfree_item.c | ||
| xfs_extfree_item.h | ||
| xfs_file.c | ||
| xfs_filestream.c | ||
| xfs_filestream.h | ||
| xfs_fs.h | ||
| xfs_fs_subr.c | ||
| xfs_fsops.c | ||
| xfs_fsops.h | ||
| xfs_globals.c | ||
| xfs_ialloc.c | ||
| xfs_ialloc.h | ||
| xfs_ialloc_btree.c | ||
| xfs_ialloc_btree.h | ||
| xfs_iget.c | ||
| xfs_inode.c | ||
| xfs_inode.h | ||
| xfs_inode_item.c | ||
| xfs_inode_item.h | ||
| xfs_inum.h | ||
| xfs_ioctl.c | ||
| xfs_ioctl.h | ||
| xfs_ioctl32.c | ||
| xfs_ioctl32.h | ||
| xfs_iomap.c | ||
| xfs_iomap.h | ||
| xfs_iops.c | ||
| xfs_iops.h | ||
| xfs_itable.c | ||
| xfs_itable.h | ||
| xfs_linux.h | ||
| xfs_log.c | ||
| xfs_log.h | ||
| xfs_log_cil.c | ||
| xfs_log_priv.h | ||
| xfs_log_recover.c | ||
| xfs_log_recover.h | ||
| xfs_message.c | ||
| xfs_message.h | ||
| xfs_mount.c | ||
| xfs_mount.h | ||
| xfs_mru_cache.c | ||
| xfs_mru_cache.h | ||
| xfs_qm.c | ||
| xfs_qm.h | ||
| xfs_qm_bhv.c | ||
| xfs_qm_syscalls.c | ||
| xfs_quota.h | ||
| xfs_quota_priv.h | ||
| xfs_quotaops.c | ||
| xfs_rename.c | ||
| xfs_rtalloc.c | ||
| xfs_rtalloc.h | ||
| xfs_rw.c | ||
| xfs_rw.h | ||
| xfs_sb.h | ||
| xfs_stats.c | ||
| xfs_stats.h | ||
| xfs_super.c | ||
| xfs_super.h | ||
| xfs_sync.c | ||
| xfs_sync.h | ||
| xfs_sysctl.c | ||
| xfs_sysctl.h | ||
| xfs_trace.c | ||
| xfs_trace.h | ||
| xfs_trans.c | ||
| xfs_trans.h | ||
| xfs_trans_ail.c | ||
| xfs_trans_buf.c | ||
| xfs_trans_dquot.c | ||
| xfs_trans_extfree.c | ||
| xfs_trans_inode.c | ||
| xfs_trans_priv.h | ||
| xfs_trans_space.h | ||
| xfs_types.h | ||
| xfs_utils.c | ||
| xfs_utils.h | ||
| xfs_vnode.h | ||
| xfs_vnodeops.c | ||
| xfs_vnodeops.h | ||
| xfs_xattr.c | ||