Improve XFS error checking and propagation
A recent paper at the FAST08 conference highlighted a large number of unchecked error paths in Linux filesystems and I/O layers. As a subsystem, XFS had the highest aggregate numbers of bad error propagation. A tarball which contains a quilt patch series of 32 patches aimed at improving this situation can be found here:
http://oss.sgi.com/~dgc/xfs/error-check/xfs-error-checking.tar.gz
The paper "EIO: Error Handling is Occasionally Correct" can be found here:
http://www.cs.wisc.edu/adsl/Publications/eio-fast08.html
And the in depth results here:
http://www.cs.wisc.edu/adsl/Publications/eio-fast08/readme.html
http://www.cs.wisc.edu/adsl/Publications/eio-fast08/
The XFS results I've been working from are here:
http://www.cs.wisc.edu/adsl/Publications/eio-fast08/fullfs-xfs-without-false-positives.txt
and included below is an annotated version of this file as I've worked through it. The graph of the XFS error paths is a good visual representation of how the bad error paths tend to cluster together:
http://www.cs.wisc.edu/adsl/Publications/eio-fast08/singlefs-xfs.pdf
(you'll need at least 800% zoom to be able to read it at all)
The paper analysed a 2.6.15 kernel, but I've been working against an xfs-dev tree (~2.6.24). Of the 101 reported problems for the 2.6.15 kernel that was analysed:
- 7 did not exist anymore (bhv layer, dirv1, write path changes)
- 11 were false positives that were not modified
- 24 were false positives that have been patched to remove (e.g. int xfs_foo() to void xfs_foo())
- 37 real problems where an error needed to be returned and are fixed in the patch series.
- 3 where there is no error path to return an error and no point in even warning about it (ENOSPC flushing)
- 10 where there is no error path to return an error, but patched to warn to the syslog about potential data loss or metadata I/O errors
- 4 were already fixed in the xfs-dev tree
- 2 where the error is ignored because we must continue anyway (patched to warn to syslog)
- 4 that I haven't yet fixed (xfs_buf_iostrategy and xfs_buf_iostart) because I need to think about them more.
Cheers,
Dave.
Signature · 135 lines
Dave Chinner Principal Engineer SGI Australian Software Group ---------------------------------------- fs/xfs/ ---- d 1 xfs_write -> _xfs_log_force fs/xfs/linux-2.6/xfs_lrw.c 881 d 2 xfs_write -> _xfs_log_force fs/xfs/linux-2.6/xfs_lrw.c 884 F 3 xfs_flush_device -> _xfs_log_force fs/xfs/linux-2.6/xfs_super.c 547 F 4 xfs_qm_dqflush -> _xfs_log_force fs/xfs/quota/xfs_dquot.c 1294 F 5 xfs_qm_dqflock_pushbuf_wait -> _xfs_log_force fs/xfs/quota/xfs_dquot.c 1591 F 6 xfs_qm_dqunpin_wait -> _xfs_log_force fs/xfs/quota/xfs_dquot_item.c 204 F 7 xfs_qm_dquot_logitem_pushbuf -> _xfs_log_force fs/xfs/quota/xfs_dquot_item.c 267 F 8 xfs_alloc_search_busy -> _xfs_log_force fs/xfs/xfs_alloc.c 2593 F 9 xfs_iunpin_wait -> _xfs_log_force fs/xfs/xfs_inode.c 2847 F 10 xfs_iflush -> _xfs_log_force fs/xfs/xfs_inode.c 3243 F 11 xfs_inode_item_pushbuf -> _xfs_log_force fs/xfs/xfs_inode_item.c 819 P 12 xfs_log_unmount_write -> _xfs_log_force fs/xfs/xfs_log.c 529 F 13 xlog_recover_finish -> _xfs_log_force fs/xfs/xfs_log_recover.c 3961 F 14 xfs_unmountfs -> _xfs_log_force fs/xfs/xfs_mount.c 1088 F 15 xfs_trans_push_ail -> _xfs_log_force fs/xfs/xfs_trans_ail.c 198 F 16 xfs_syncsub -> _xfs_log_force fs/xfs/xfs_vfsops.c 1440 F 17 xfs_syncsub -> _xfs_log_force fs/xfs/xfs_vfsops.c 1455 F 18 xfs_syncsub -> _xfs_log_force fs/xfs/xfs_vfsops.c 1491 F 19 xfs_syncsub -> _xfs_log_force fs/xfs/xfs_vfsops.c 1543 P 20 xfs_fsync -> _xfs_log_force fs/xfs/xfs_vnodeops.c 1129 P 21 xfs_qm_write_sb_changes -> _xfs_trans_commit fs/xfs/quota/xfs_qm.c 2414 P 22 xfs_qm_scall_setqlim -> _xfs_trans_commit fs/xfs/quota/xfs_qm_syscalls.c 739 P 23 xfs_itruncate_finish -> _xfs_trans_commit fs/xfs/xfs_inode.c 1718 P 24 xlog_recover_process_efi -> _xfs_trans_commit fs/xfs/xfs_log_recover.c 3047 P 25 xlog_recover_clear_agi_bucket -> _xfs_trans_commit fs/xfs/xfs_log_recover.c 3174 PB 26 xfs_mount_log_sbunit -> _xfs_trans_commit fs/xfs/xfs_mount.c 1579 P 27 xfs_growfs_rt_alloc -> _xfs_trans_commit fs/xfs/xfs_rtalloc.c 154 P 28 xfs_growfs_rt_alloc -> _xfs_trans_commit fs/xfs/xfs_rtalloc.c 191 P 29 xfs_growfs_rt -> _xfs_trans_commit fs/xfs/xfs_rtalloc.c 2103 P 30 xfs_inactive_attrs -> _xfs_trans_commit fs/xfs/xfs_vnodeops.c 1505 C 31 xfs_inactive -> _xfs_trans_commit fs/xfs/xfs_vnodeops.c 1790 d 32 xfs_initialize_vnode -> bhv_insert fs/xfs/linux-2.6/xfs_super.c 220 d 33 vfs_insertops -> bhv_insert fs/xfs/linux-2.6/xfs_vfs.c 259 N 34 linvfs_truncate -> block_truncate_page fs/xfs/linux-2.6/xfs_iops.c 651 G 35 fs_flushinval_pages -> filemap_fdatawait fs/xfs/linux-2.6/xfs_fs_subr.c 83 G 36 fs_flush_pages -> filemap_fdatawait fs/xfs/linux-2.6/xfs_fs_subr.c 108 G 37 fs_flushinval_pages -> filemap_fdatawrite fs/xfs/linux-2.6/xfs_fs_subr.c 82 G 38 fs_flush_pages -> filemap_fdatawrite fs/xfs/linux-2.6/xfs_fs_subr.c 105 n 39 xfs_flush_inode_work -> filemap_flush fs/xfs/linux-2.6/xfs_super.c 508 PM 40 xlog_sync -> pagebuf_associate_memory fs/xfs/xfs_log.c 1358 PM 41 xlog_sync -> pagebuf_associate_memory fs/xfs/xfs_log.c 1395 PM 42 xlog_write_log_records -> pagebuf_associate_memory fs/xfs/xfs_log_recover.c 1156 PM 43 xlog_write_log_records -> pagebuf_associate_memory fs/xfs/xfs_log_recover.c 1159 PM 44 xlog_do_recovery_pass -> pagebuf_associate_memory fs/xfs/xfs_log_recover.c 3646 PM 45 xlog_do_recovery_pass -> pagebuf_associate_memory fs/xfs/xfs_log_recover.c 3653 PM 46 xlog_do_recovery_pass -> pagebuf_associate_memory fs/xfs/xfs_log_recover.c 3705 PM 47 xlog_do_recovery_pass -> pagebuf_associate_memory fs/xfs/xfs_log_recover.c 3711 M 48 xfs_buf_read_flags -> pagebuf_iostart fs/xfs/linux-2.6/xfs_buf.c 636 M 49 xfsbufd -> pagebuf_iostrategy fs/xfs/linux-2.6/xfs_buf.c 1755 M 50 xfs_flush_buftarg -> pagebuf_iostrategy fs/xfs/linux-2.6/xfs_buf.c 1816 M 51 XFS_bwrite -> pagebuf_iostrategy fs/xfs/linux-2.6/xfs_buf.h 503 n 52 xfs_flush_device_work -> sync_blockdev fs/xfs/linux-2.6/xfs_super.c 533 f 53 exit_xfs_fs -> unregister_filesystem fs/xfs/linux-2.6/xfs_super.c 999 PM 54 xfs_acl_vset -> xfs_acl_vremove fs/xfs/xfs_acl.c 326 f 55 xfs_ialloc_ag_select -> xfs_alloc_pagf_init fs/xfs/xfs_ialloc.c 411 P 56 xfs_qm_dqflush -> xfs_bawrite fs/xfs/quota/xfs_dquot.c 1300 N 57 xfs_qm_dqflock_pushbuf_wait -> xfs_bawrite fs/xfs/quota/xfs_dquot.c 1595 N 58 xfs_qm_dquot_logitem_pushbuf -> xfs_bawrite fs/xfs/quota/xfs_dquot_item.c 275 N 59 xfs_buf_item_push -> xfs_bawrite fs/xfs/xfs_buf_item.c 669 P 60 xfs_iflush -> xfs_bawrite fs/xfs/xfs_inode.c 3249 N 61 xfs_inode_item_pushbuf -> xfs_bawrite fs/xfs/xfs_inode_item.c 823 F 62 xfs_qm_dqflush -> xfs_bdwrite fs/xfs/quota/xfs_dquot.c 1298 F 63 xfs_qm_dqiter_bufs -> xfs_bdwrite fs/xfs/quota/xfs_qm.c 1551 F 64 xfs_iflush -> xfs_bdwrite fs/xfs/xfs_inode.c 3247 F 65 xlog_recover_do_buffer_trans -> xfs_bdwrite fs/xfs/xfs_log_recover.c 2271 F 66 xlog_recover_do_inode_trans -> xfs_bdwrite fs/xfs/xfs_log_recover.c 2535 F 67 xlog_recover_do_dquot_trans -> xfs_bdwrite fs/xfs/xfs_log_recover.c 2664 C 68 xfs_inactive -> xfs_bmap_finish fs/xfs/xfs_vnodeops.c 1788 P 69 xfs_iomap_write_allocate -> xfs_bmap_last_offset fs/xfs/xfs_iomap.c 787 d 70 xfs_dir_leaf_rebalance -> xfs_dir_leaf_compact fs/xfs/xfs_dir_leaf.c 1146 d 71 xfs_dir_leaf_rebalance -> xfs_dir_leaf_compact fs/xfs/xfs_dir_leaf.c 1176 d 72 xfs_dir_leaf_to_shortform -> xfs_dir_shortform_addname fs/xfs/xfs_dir_leaf.c 693 P 73 xlog_recover_process_efi -> xfs_free_extent fs/xfs/xfs_log_recover.c 3041 n 74 xfs_inode_item_push -> xfs_iflush fs/xfs/xfs_inode_item.c 879 P 75 xlog_recover_do_inode_trans -> xfs_imap fs/xfs/xfs_log_recover.c 2320 f 76 xfs_bmap_add_extent -> xfs_mod_incore_sb fs/xfs/xfs_bmap.c 689 f 77 xfs_bmap_add_extent_hole_delay -> xfs_mod_incore_sb fs/xfs/xfs_bmap.c 1918 f 78 xfs_bmap_del_extent -> xfs_mod_incore_sb fs/xfs/xfs_bmap.c 3117 f 79 xfs_bmapi -> xfs_mod_incore_sb fs/xfs/xfs_bmap.c 4801 f 80 xfs_bmapi -> xfs_mod_incore_sb fs/xfs/xfs_bmap.c 4805 f 81 xfs_bunmapi -> xfs_mod_incore_sb fs/xfs/xfs_bmap.c 5452 f 82 xfs_bunmapi -> xfs_mod_incore_sb fs/xfs/xfs_bmap.c 5458 f 83 xfs_trans_reserve -> xfs_mod_incore_sb fs/xfs/xfs_trans.c 305 P 84 xfs_qm_quotacheck -> xfs_mount_reset_sbqflags fs/xfs/quota/xfs_qm.c 1962 N 85 xfs_qm_dqpurge -> xfs_qm_dqflush fs/xfs/quota/xfs_dquot.c 1505 NB 86 xfs_qm_dquot_logitem_push -> xfs_qm_dqflush fs/xfs/quota/xfs_dquot_item.c 168 N 87 xfs_qm_shake_freelist -> xfs_qm_dqflush fs/xfs/quota/xfs_qm.c 2134 N 88 xfs_qm_dqreclaim_one -> xfs_qm_dqflush fs/xfs/quota/xfs_qm.c 2306 PM 89 xfs_qm_quotacheck -> xfs_qm_dqflush_all fs/xfs/quota/xfs_qm.c 1930 P 90 xfs_qm_scall_quotaoff -> xfs_qm_log_quotaoff fs/xfs/quota/xfs_qm_syscalls.c 291 P 91 xfs_qm_scall_quotaoff -> xfs_qm_log_quotaoff_end fs/xfs/quota/xfs_qm_syscalls.c 347 F 92 xfs_qm_newmount -> xfs_qm_mount_quotas fs/xfs/quota/xfs_qm_bhv.c 273 F 93 xfs_qm_endmount -> xfs_qm_mount_quotas fs/xfs/quota/xfs_qm_bhv.c 301 PM 94 xfs_quiesce_fs -> xfs_syncsub fs/xfs/xfs_vfsops.c 632 P 95 xlog_recover_process_efi -> xfs_trans_reserve fs/xfs/xfs_log_recover.c 3036 P 96 xlog_recover_clear_agi_bucket -> xfs_trans_reserve fs/xfs/xfs_log_recover.c 3152 P 97 xfs_qm_scall_trunc_qfiles -> xfs_truncate_file fs/xfs/quota/xfs_qm_syscalls.c 395 P 98 xfs_qm_scall_trunc_qfiles -> xfs_truncate_file fs/xfs/quota/xfs_qm_syscalls.c 404 P 99 xfs_log_unmount_write -> xlog_state_release_iclog fs/xfs/xfs_log.c 570 P 100 xfs_log_unmount_write -> xlog_state_release_iclog fs/xfs/xfs_log.c 606 f 101 xfs_log_force_umount -> xlog_state_sync_all fs/xfs/xfs_log.c 3586 f = false positive F = false positive + patch to remove condition G = patch in mainline git tree already M = __must_check annotations found this as well P = real, patch to fix n = no error path to return error N = no error path to return error, patch to warn about error added d = does not exist anymore. B = some other bug found and fixed at same time C = error ignored, must continue anyway. If silent, made noisy Notes: - all the xfs_mod_incore_sb() are false positive because they are freeing blocks or extents which means there can never be an error returned. The only error that can be returned is ENOSPC when trying to allocate blocks.... - none of the callers of xfs_mount_log_sb() check the return value. - new function xfs_log_sbcount failed to check return of xfs_trans_commit. Callers are failing to check return value. - most of the callers to xfs_log_force() are not interested in errors - they'll get them through other means (i.e. log error implies filesystem shutdown). Only a handful of callers really should return errors, such as fsync(), sync writes or synchronous transaction commits.
ping?
Quoted 192 lines · David Chinner
A recent paper at the FAST08 conference highlighted a large number of unchecked error paths in Linux filesystems and I/O layers. As a subsystem, XFS had the highest aggregate numbers of bad error propagation. A tarball which contains a quilt patch series of 32 patches aimed at improving this situation can be found here:
http://oss.sgi.com/~dgc/xfs/error-check/xfs-error-checking.tar.gz
The paper "EIO: Error Handling is Occasionally Correct" can be found here:
http://www.cs.wisc.edu/adsl/Publications/eio-fast08.html
And the in depth results here:
http://www.cs.wisc.edu/adsl/Publications/eio-fast08/readme.html
http://www.cs.wisc.edu/adsl/Publications/eio-fast08/The XFS results I've been working from are here:
http://www.cs.wisc.edu/adsl/Publications/eio-fast08/fullfs-xfs-without-false-positives.txt
and included below is an annotated version of this file as I've worked through it. The graph of the XFS error paths is a good visual representation of how the bad error paths tend to cluster together:
http://www.cs.wisc.edu/adsl/Publications/eio-fast08/singlefs-xfs.pdf
(you'll need at least 800% zoom to be able to read it at all)
The paper analysed a 2.6.15 kernel, but I've been working against an xfs-dev tree (~2.6.24). Of the 101 reported problems for the 2.6.15 kernel that was analysed:
- 7 did not exist anymore (bhv layer, dirv1, write path changes)
- 11 were false positives that were not modified
- 24 were false positives that have been patched to remove (e.g. intxfs_foo()to voidxfs_foo())
- 37 real problems where an error needed to be returned and are fixed in the patch series.
- 3 where there is no error path to return an error and no point in even warning about it (ENOSPC flushing)
- 10 where there is no error path to return an error, but patched to warn to the syslog about potential data loss or metadata I/O errors
- 4 were already fixed in the xfs-dev tree
- 2 where the error is ignored because we must continue anyway (patched to warn to syslog)
- 4 that I haven't yet fixed (xfs_buf_iostrategyandxfs_buf_iostart) because I need to think about them more.Cheers,
Dave.
Signature · 135 lines
Dave Chinner Principal Engineer SGI Australian Software Group ---------------------------------------- fs/xfs/ ---- d 1 xfs_write -> _xfs_log_force fs/xfs/linux-2.6/xfs_lrw.c 881 d 2 xfs_write -> _xfs_log_force fs/xfs/linux-2.6/xfs_lrw.c 884 F 3 xfs_flush_device -> _xfs_log_force fs/xfs/linux-2.6/xfs_super.c 547 F 4 xfs_qm_dqflush -> _xfs_log_force fs/xfs/quota/xfs_dquot.c 1294 F 5 xfs_qm_dqflock_pushbuf_wait -> _xfs_log_force fs/xfs/quota/xfs_dquot.c 1591 F 6 xfs_qm_dqunpin_wait -> _xfs_log_force fs/xfs/quota/xfs_dquot_item.c 204 F 7 xfs_qm_dquot_logitem_pushbuf -> _xfs_log_force fs/xfs/quota/xfs_dquot_item.c 267 F 8 xfs_alloc_search_busy -> _xfs_log_force fs/xfs/xfs_alloc.c 2593 F 9 xfs_iunpin_wait -> _xfs_log_force fs/xfs/xfs_inode.c 2847 F 10 xfs_iflush -> _xfs_log_force fs/xfs/xfs_inode.c 3243 F 11 xfs_inode_item_pushbuf -> _xfs_log_force fs/xfs/xfs_inode_item.c 819 P 12 xfs_log_unmount_write -> _xfs_log_force fs/xfs/xfs_log.c 529 F 13 xlog_recover_finish -> _xfs_log_force fs/xfs/xfs_log_recover.c 3961 F 14 xfs_unmountfs -> _xfs_log_force fs/xfs/xfs_mount.c 1088 F 15 xfs_trans_push_ail -> _xfs_log_force fs/xfs/xfs_trans_ail.c 198 F 16 xfs_syncsub -> _xfs_log_force fs/xfs/xfs_vfsops.c 1440 F 17 xfs_syncsub -> _xfs_log_force fs/xfs/xfs_vfsops.c 1455 F 18 xfs_syncsub -> _xfs_log_force fs/xfs/xfs_vfsops.c 1491 F 19 xfs_syncsub -> _xfs_log_force fs/xfs/xfs_vfsops.c 1543 P 20 xfs_fsync -> _xfs_log_force fs/xfs/xfs_vnodeops.c 1129 P 21 xfs_qm_write_sb_changes -> _xfs_trans_commit fs/xfs/quota/xfs_qm.c 2414 P 22 xfs_qm_scall_setqlim -> _xfs_trans_commit fs/xfs/quota/xfs_qm_syscalls.c 739 P 23 xfs_itruncate_finish -> _xfs_trans_commit fs/xfs/xfs_inode.c 1718 P 24 xlog_recover_process_efi -> _xfs_trans_commit fs/xfs/xfs_log_recover.c 3047 P 25 xlog_recover_clear_agi_bucket -> _xfs_trans_commit fs/xfs/xfs_log_recover.c 3174 PB 26 xfs_mount_log_sbunit -> _xfs_trans_commit fs/xfs/xfs_mount.c 1579 P 27 xfs_growfs_rt_alloc -> _xfs_trans_commit fs/xfs/xfs_rtalloc.c 154 P 28 xfs_growfs_rt_alloc -> _xfs_trans_commit fs/xfs/xfs_rtalloc.c 191 P 29 xfs_growfs_rt -> _xfs_trans_commit fs/xfs/xfs_rtalloc.c 2103 P 30 xfs_inactive_attrs -> _xfs_trans_commit fs/xfs/xfs_vnodeops.c 1505 C 31 xfs_inactive -> _xfs_trans_commit fs/xfs/xfs_vnodeops.c 1790 d 32 xfs_initialize_vnode -> bhv_insert fs/xfs/linux-2.6/xfs_super.c 220 d 33 vfs_insertops -> bhv_insert fs/xfs/linux-2.6/xfs_vfs.c 259 N 34 linvfs_truncate -> block_truncate_page fs/xfs/linux-2.6/xfs_iops.c 651 G 35 fs_flushinval_pages -> filemap_fdatawait fs/xfs/linux-2.6/xfs_fs_subr.c 83 G 36 fs_flush_pages -> filemap_fdatawait fs/xfs/linux-2.6/xfs_fs_subr.c 108 G 37 fs_flushinval_pages -> filemap_fdatawrite fs/xfs/linux-2.6/xfs_fs_subr.c 82 G 38 fs_flush_pages -> filemap_fdatawrite fs/xfs/linux-2.6/xfs_fs_subr.c 105 n 39 xfs_flush_inode_work -> filemap_flush fs/xfs/linux-2.6/xfs_super.c 508 PM 40 xlog_sync -> pagebuf_associate_memory fs/xfs/xfs_log.c 1358 PM 41 xlog_sync -> pagebuf_associate_memory fs/xfs/xfs_log.c 1395 PM 42 xlog_write_log_records -> pagebuf_associate_memory fs/xfs/xfs_log_recover.c 1156 PM 43 xlog_write_log_records -> pagebuf_associate_memory fs/xfs/xfs_log_recover.c 1159 PM 44 xlog_do_recovery_pass -> pagebuf_associate_memory fs/xfs/xfs_log_recover.c 3646 PM 45 xlog_do_recovery_pass -> pagebuf_associate_memory fs/xfs/xfs_log_recover.c 3653 PM 46 xlog_do_recovery_pass -> pagebuf_associate_memory fs/xfs/xfs_log_recover.c 3705 PM 47 xlog_do_recovery_pass -> pagebuf_associate_memory fs/xfs/xfs_log_recover.c 3711 M 48 xfs_buf_read_flags -> pagebuf_iostart fs/xfs/linux-2.6/xfs_buf.c 636 M 49 xfsbufd -> pagebuf_iostrategy fs/xfs/linux-2.6/xfs_buf.c 1755 M 50 xfs_flush_buftarg -> pagebuf_iostrategy fs/xfs/linux-2.6/xfs_buf.c 1816 M 51 XFS_bwrite -> pagebuf_iostrategy fs/xfs/linux-2.6/xfs_buf.h 503 n 52 xfs_flush_device_work -> sync_blockdev fs/xfs/linux-2.6/xfs_super.c 533 f 53 exit_xfs_fs -> unregister_filesystem fs/xfs/linux-2.6/xfs_super.c 999 PM 54 xfs_acl_vset -> xfs_acl_vremove fs/xfs/xfs_acl.c 326 f 55 xfs_ialloc_ag_select -> xfs_alloc_pagf_init fs/xfs/xfs_ialloc.c 411 P 56 xfs_qm_dqflush -> xfs_bawrite fs/xfs/quota/xfs_dquot.c 1300 N 57 xfs_qm_dqflock_pushbuf_wait -> xfs_bawrite fs/xfs/quota/xfs_dquot.c 1595 N 58 xfs_qm_dquot_logitem_pushbuf -> xfs_bawrite fs/xfs/quota/xfs_dquot_item.c 275 N 59 xfs_buf_item_push -> xfs_bawrite fs/xfs/xfs_buf_item.c 669 P 60 xfs_iflush -> xfs_bawrite fs/xfs/xfs_inode.c 3249 N 61 xfs_inode_item_pushbuf -> xfs_bawrite fs/xfs/xfs_inode_item.c 823 F 62 xfs_qm_dqflush -> xfs_bdwrite fs/xfs/quota/xfs_dquot.c 1298 F 63 xfs_qm_dqiter_bufs -> xfs_bdwrite fs/xfs/quota/xfs_qm.c 1551 F 64 xfs_iflush -> xfs_bdwrite fs/xfs/xfs_inode.c 3247 F 65 xlog_recover_do_buffer_trans -> xfs_bdwrite fs/xfs/xfs_log_recover.c 2271 F 66 xlog_recover_do_inode_trans -> xfs_bdwrite fs/xfs/xfs_log_recover.c 2535 F 67 xlog_recover_do_dquot_trans -> xfs_bdwrite fs/xfs/xfs_log_recover.c 2664 C 68 xfs_inactive -> xfs_bmap_finish fs/xfs/xfs_vnodeops.c 1788 P 69 xfs_iomap_write_allocate -> xfs_bmap_last_offset fs/xfs/xfs_iomap.c 787 d 70 xfs_dir_leaf_rebalance -> xfs_dir_leaf_compact fs/xfs/xfs_dir_leaf.c 1146 d 71 xfs_dir_leaf_rebalance -> xfs_dir_leaf_compact fs/xfs/xfs_dir_leaf.c 1176 d 72 xfs_dir_leaf_to_shortform -> xfs_dir_shortform_addname fs/xfs/xfs_dir_leaf.c 693 P 73 xlog_recover_process_efi -> xfs_free_extent fs/xfs/xfs_log_recover.c 3041 n 74 xfs_inode_item_push -> xfs_iflush fs/xfs/xfs_inode_item.c 879 P 75 xlog_recover_do_inode_trans -> xfs_imap fs/xfs/xfs_log_recover.c 2320 f 76 xfs_bmap_add_extent -> xfs_mod_incore_sb fs/xfs/xfs_bmap.c 689 f 77 xfs_bmap_add_extent_hole_delay -> xfs_mod_incore_sb fs/xfs/xfs_bmap.c 1918 f 78 xfs_bmap_del_extent -> xfs_mod_incore_sb fs/xfs/xfs_bmap.c 3117 f 79 xfs_bmapi -> xfs_mod_incore_sb fs/xfs/xfs_bmap.c 4801 f 80 xfs_bmapi -> xfs_mod_incore_sb fs/xfs/xfs_bmap.c 4805 f 81 xfs_bunmapi -> xfs_mod_incore_sb fs/xfs/xfs_bmap.c 5452 f 82 xfs_bunmapi -> xfs_mod_incore_sb fs/xfs/xfs_bmap.c 5458 f 83 xfs_trans_reserve -> xfs_mod_incore_sb fs/xfs/xfs_trans.c 305 P 84 xfs_qm_quotacheck -> xfs_mount_reset_sbqflags fs/xfs/quota/xfs_qm.c 1962 N 85 xfs_qm_dqpurge -> xfs_qm_dqflush fs/xfs/quota/xfs_dquot.c 1505 NB 86 xfs_qm_dquot_logitem_push -> xfs_qm_dqflush fs/xfs/quota/xfs_dquot_item.c 168 N 87 xfs_qm_shake_freelist -> xfs_qm_dqflush fs/xfs/quota/xfs_qm.c 2134 N 88 xfs_qm_dqreclaim_one -> xfs_qm_dqflush fs/xfs/quota/xfs_qm.c 2306 PM 89 xfs_qm_quotacheck -> xfs_qm_dqflush_all fs/xfs/quota/xfs_qm.c 1930 P 90 xfs_qm_scall_quotaoff -> xfs_qm_log_quotaoff fs/xfs/quota/xfs_qm_syscalls.c 291 P 91 xfs_qm_scall_quotaoff -> xfs_qm_log_quotaoff_end fs/xfs/quota/xfs_qm_syscalls.c 347 F 92 xfs_qm_newmount -> xfs_qm_mount_quotas fs/xfs/quota/xfs_qm_bhv.c 273 F 93 xfs_qm_endmount -> xfs_qm_mount_quotas fs/xfs/quota/xfs_qm_bhv.c 301 PM 94 xfs_quiesce_fs -> xfs_syncsub fs/xfs/xfs_vfsops.c 632 P 95 xlog_recover_process_efi -> xfs_trans_reserve fs/xfs/xfs_log_recover.c 3036 P 96 xlog_recover_clear_agi_bucket -> xfs_trans_reserve fs/xfs/xfs_log_recover.c 3152 P 97 xfs_qm_scall_trunc_qfiles -> xfs_truncate_file fs/xfs/quota/xfs_qm_syscalls.c 395 P 98 xfs_qm_scall_trunc_qfiles -> xfs_truncate_file fs/xfs/quota/xfs_qm_syscalls.c 404 P 99 xfs_log_unmount_write -> xlog_state_release_iclog fs/xfs/xfs_log.c 570 P 100 xfs_log_unmount_write -> xlog_state_release_iclog fs/xfs/xfs_log.c 606 f 101 xfs_log_force_umount -> xlog_state_sync_all fs/xfs/xfs_log.c 3586 f = false positive F = false positive + patch to remove condition G = patch in mainline git tree already M = __must_check annotations found this as well P = real, patch to fix n = no error path to return error N = no error path to return error, patch to warn about error added d = does not exist anymore. B = some other bug found and fixed at same time C = error ignored, must continue anyway. If silent, made noisy Notes: - all the xfs_mod_incore_sb() are false positive because they are freeing blocks or extents which means there can never be an error returned. The only error that can be returned is ENOSPC when trying to allocate blocks.... - none of the callers of xfs_mount_log_sb() check the return value. - new function xfs_log_sbcount failed to check return of xfs_trans_commit. Callers are failing to check return value. - most of the callers to xfs_log_force() are not interested in errors - they'll get them through other means (i.e. log error implies filesystem shutdown). Only a handful of callers really should return errors, such as fsync(), sync writes or synchronous transaction commits.
Signature · 3 lines
Dave Chinner Principal Engineer SGI Australian Software Group
Quoted 8 lines · David Chinner
Quoted 7 lines · David Chinner
A recent paper at the FAST08 conference highlighted a large number of unchecked error paths in Linux filesystems and I/O layers. As a subsystem, XFS had the highest aggregate numbers of bad error propagation. A tarball which contains a quilt patch series of 32 patches aimed at improving this situation can be found here:
http://oss.sgi.com/~dgc/xfs/error-check/xfs-error-checking.tar.gz
All looks good except some minor typo-editing,
and
NOK xfs-mustcheck-quotamount.patch # need to check if can happen when forcing quotas
I'm not sure what happens if we really DO want quotas (specified on mount line and such).
OK xfs-mustcheck-reset-dqcounts.patch
OK xfs-mustcheck-dqflushall.patch
OK xfs-mustcheck-acl-setmode.patch
OK xfs-mustcheck-search-busy.patch
EDITED xfs-mustcheck-compute-diff.patch # xfs_fs_cmn_err alignment OK xfs-mustcheck-bmap-adjacent.patch
OK xfs-mustcheck-iflush-fork.patch # less error handeling !! OK xfs-mustcheck-bulkstat-dinode.patch
OK xfs-mustcheck-quiesce-fs.patch
OK xfs-mustcheck-bdstrat.patch
OK xfs-fix-error-prototypes.patch # not error handeling related OK xfs-mustcheck-acl-vremove.patch
OK xfs-mustcheck-icsb-disable.patch
OK xfs-mustcheck-ioend-unwritten.patch
OK xfs-mustcheck-buf-associate.patch
OK xfs-mustcheck-reserve-blocks.patch
EDITED xfs-mustcheck-bawrite.patch # xfs_fs_cmn_err alignment OK xfs-mustcheck-bdwrite.patch
OK xfs-mustcheck-truncate-page.patch # might be incomplete EDITED xfs-mustcheck-dqflush.patch # slight style change/typo OK xfs-mustcheck-reset-sbqflags.patch
OK xfs-mustcheck-quotaoff.patch
EDITED xfs-mustcheck-inactive.patch # slight style change/typo OK xfs-mustcheck-trans-reserve.patch
OK xfs-mustcheck-quota-trunc.patch
OK xfs-mustcheck-log-unmount.patch
OK xfs-mustcheck-free-extent.patch
OK xfs-mustcheck-xfs-imap.patch
OK xfs-mustcheck-bmap-last-offset.patch
OK xfs-mustcheck-trans-commit.patch
OK xfs-mustcheck-log-force.patch
Cheers,
Signature · 1 line
Niv Sardi
Quoted 10 lines · Niv Sardi
Quoted 8 lines · David Chinner
Quoted 7 lines · David Chinner
A recent paper at the FAST08 conference highlighted a large number of unchecked error paths in Linux filesystems and I/O layers. As a subsystem, XFS had the highest aggregate numbers of bad error propagation. A tarball which contains a quilt patch series of 32 patches aimed at improving this situation can be found here:
http://oss.sgi.com/~dgc/xfs/error-check/xfs-error-checking.tar.gz
Quoted 8 lines
All looks good except some minor typo-editing,
and
NOK xfs-mustcheck-quotamount.patch # need to check if can happen when forcing quotas
I'm not sure what happens if we really DO want quotas (specified on mount line and such).
The behaviour will be exactly the same as previously, because the error returned by xfs_qm_mount_quotas() is ignored. i.e. if we try to mount with quotas and the quota mount fails, we continue (after issuing a warning to syslog) that quotas were not turned on.
This is especially important for root filesystems with quota enabled....
Quoted 5 lines
OK xfs-mustcheck-reset-dqcounts.patch
OK xfs-mustcheck-dqflushall.patch
OK xfs-mustcheck-acl-setmode.patch
OK xfs-mustcheck-search-busy.patch
EDITED xfs-mustcheck-compute-diff.patch #xfs_fs_cmn_erralignment
That patch doesn't have any calls to xfs_fs_cmn_err() in it. Can you clarify, please?
Quoted 2 lines
OK xfs-mustcheck-bmap-adjacent.patch
OK xfs-mustcheck-iflush-fork.patch # less error handeling !!
You can't have less error handling than intentionally ignoring the return from a function that can't return an error. You can have simpler code, though, by declaring the function void....
Quoted 10 lines
OK xfs-mustcheck-bulkstat-dinode.patch
OK xfs-mustcheck-quiesce-fs.patch
OK xfs-mustcheck-bdstrat.patch
OK xfs-fix-error-prototypes.patch # not error handeling related OK xfs-mustcheck-acl-vremove.patch
OK xfs-mustcheck-icsb-disable.patch
OK xfs-mustcheck-ioend-unwritten.patch
OK xfs-mustcheck-buf-associate.patch
OK xfs-mustcheck-reserve-blocks.patch
EDITED xfs-mustcheck-bawrite.patch #xfs_fs_cmn_erralignment
Which means?
Quoted 2 lines
OK xfs-mustcheck-bdwrite.patch
OK xfs-mustcheck-truncate-page.patch # might be incomplete
Incomplete in what way?
Quoted 1 line
EDITED xfs-mustcheck-dqflush.patch # slight style change/typo
Details?
Quoted 3 lines
OK xfs-mustcheck-reset-sbqflags.patch
OK xfs-mustcheck-quotaoff.patch
EDITED xfs-mustcheck-inactive.patch # slight style change/typo
Details?
Cheers,
Dave.
Signature · 3 lines
Dave Chinner Principal Engineer SGI Australian Software Group
Quoted 20 lines · David Chinner
Quoted 10 lines · Niv Sardi
Quoted 8 lines · David Chinner
Quoted 7 lines · David Chinner
A recent paper at the FAST08 conference highlighted a large number of unchecked error paths in Linux filesystems and I/O layers. As a subsystem, XFS had the highest aggregate numbers of bad error propagation. A tarball which contains a quilt patch series of 32 patches aimed at improving this situation can be found here:
http://oss.sgi.com/~dgc/xfs/error-check/xfs-error-checking.tar.gz
Quoted 8 lines
All looks good except some minor typo-editing,
and
NOK xfs-mustcheck-quotamount.patch # need to check if can happen when forcing quotas
I'm not sure what happens if we really DO want quotas (specified on mount line and such).
Quoted 7 lines
The behaviour will be exactly the same as previously, because the error returned by
xfs_qm_mount_quotas()is ignored. i.e. if we try to mount with quotas and the quota mount fails, we continue (after issuing a warning to syslog) that quotas were not turned on.This is especially important for root filesystems with quota enabled....
OK, I wasn't sure.
All the rest are minor aesthetics/typos my messed up notes, and can be ignored…
Quoted 8 lines
Quoted 5 lines
OK xfs-mustcheck-reset-dqcounts.patch
OK xfs-mustcheck-dqflushall.patch
OK xfs-mustcheck-acl-setmode.patch
OK xfs-mustcheck-search-busy.patch
EDITED xfs-mustcheck-compute-diff.patch #xfs_fs_cmn_erralignmentThat patch doesn't have any calls to
xfs_fs_cmn_err()in it. Can you clarify, please?
Oops, the edit was for:
-+STATIC void /* success (>= minlen) */
++STATIC void
as it didn't really make sense anymore.
Quoted 6 lines
Quoted 2 lines
OK xfs-mustcheck-bmap-adjacent.patch
OK xfs-mustcheck-iflush-fork.patch # less error handeling !!You can't have less error handling than intentionally ignoring the return from a function that can't return an error. You can have simpler code, though, by declaring the function void....
hum, I can't remember why I wrote that anymore, oh well… looks good now.
Quoted 11 lines
Quoted 10 lines
OK xfs-mustcheck-bulkstat-dinode.patch
OK xfs-mustcheck-quiesce-fs.patch
OK xfs-mustcheck-bdstrat.patch
OK xfs-fix-error-prototypes.patch # not error handeling related OK xfs-mustcheck-acl-vremove.patch
OK xfs-mustcheck-icsb-disable.patch
OK xfs-mustcheck-ioend-unwritten.patch
OK xfs-mustcheck-buf-associate.patch
OK xfs-mustcheck-reserve-blocks.patch
EDITED xfs-mustcheck-bawrite.patch #xfs_fs_cmn_erralignment
Quoted 1 line
Which means?
That's purely aesthetic, sometimes we split the string and keep it aligned, and sometimes we pad it left so that it fits, I prefer splitting.
Quoted 2 lines
Quoted 2 lines
OK xfs-mustcheck-bdwrite.patch
OK xfs-mustcheck-truncate-page.patch # might be incomplete
Note to self: re-read one's notes before sending them out, I wanted to look at why we couldn't propagate error better, but now it's all understood =)
Quoted 2 lines
Quoted 1 line
EDITED xfs-mustcheck-dqflush.patch # slight style change/typo
Details?
-hence we nevre know if we've failed to flush a dquot to disk. +hence we never know if we've failed to flush a dquot to disk.
and xfs_fs_cmn_err stuff.
Quoted 5 lines
Quoted 3 lines
OK xfs-mustcheck-reset-sbqflags.patch
OK xfs-mustcheck-quotaoff.patch
EDITED xfs-mustcheck-inactive.patch # slight style change/typoDetails?
-correctly. if we fail to write the final quota off trnasaction, +correctly. if we fail to write the final quota off transaction,
and xfs_fs_cmn_err stuff.
Cheers,
Signature · 1 line
Niv Sardi
Quoted 9 lines · Niv Sardi
Quoted 7 lines · David Chinner
Quoted 5 lines · Niv Sardi
OK xfs-mustcheck-reset-dqcounts.patch
OK xfs-mustcheck-dqflushall.patch
OK xfs-mustcheck-acl-setmode.patch
OK xfs-mustcheck-search-busy.patch
EDITED xfs-mustcheck-compute-diff.patch #xfs_fs_cmn_erralignment
Quoted 8 lines
Quoted 2 lines
That patch doesn't have any calls to
xfs_fs_cmn_err()in it. Can you clarify, please?Oops, the edit was for:
-+STATIC void /* success (>= minlen) */
++STATIC voidas it didn't really make sense anymore.
Ok, Fixed.
Quoted 11 lines
Quoted 11 lines
Quoted 10 lines
OK xfs-mustcheck-bulkstat-dinode.patch
OK xfs-mustcheck-quiesce-fs.patch
OK xfs-mustcheck-bdstrat.patch
OK xfs-fix-error-prototypes.patch # not error handeling related OK xfs-mustcheck-acl-vremove.patch
OK xfs-mustcheck-icsb-disable.patch
OK xfs-mustcheck-ioend-unwritten.patch
OK xfs-mustcheck-buf-associate.patch
OK xfs-mustcheck-reserve-blocks.patch
EDITED xfs-mustcheck-bawrite.patch #xfs_fs_cmn_erralignment
Quoted 5 lines
Quoted 1 line
Which means?
That's purely aesthetic, sometimes we split the string and keep it aligned, and sometimes we pad it left so that it fits, I prefer splitting.
Ok. If it involves splitting a string into 3 lines because of indentation, then I tend to do one long line. i.e. this:
if (error) xfs_fs_cmn_err(CE_WARN, mp, "xfs_qm_dquot_logitem_pushbuf: pushbuf error %d on qip %p, bp %p", error, qip, bp);
Instead of:
if (error) xfs_fs_cmn_err(CE_WARN, mp, "xfs_qm_dquot_logitem_pushbuf:" " pushbuf error %d on qip %p, " " bp %p", error, qip, bp);
The first is much easier to read and grep for....
Review
Quoted 5 lines
Quoted 2 lines
Quoted 1 line
EDITED xfs-mustcheck-dqflush.patch # slight style change/typo
Details?
(quoted diff) +1
-1-hence we nevre know if we've failed to flush a dquot to disk. +hence we never know if we've failed to flush a dquot to disk.
Oh, in the patch description....
Quoted 1 line
and
xfs_fs_cmn_errstuff.
Same as above...
Review
Quoted 8 lines
Quoted 5 lines
Quoted 3 lines
OK xfs-mustcheck-reset-sbqflags.patch
OK xfs-mustcheck-quotaoff.patch
EDITED xfs-mustcheck-inactive.patch # slight style change/typoDetails?
(quoted diff) +1
-1-correctly. if we fail to write the final quota off trnasaction, +correctly. if we fail to write the final quota off transaction,
Ah, that's from the quotaoff patch. No wonder I couldn't find the typo ;)
But I also split the xfs_fs_cmn_err() in xfs-mustcheck-inactive (much nicer).
All fixed up. Thanks Niv.
Cheers,
Dave.
Signature · 3 lines
Dave Chinner Principal Engineer SGI Australian Software Group