* [Review] Improve XFS error checking and propagation
@ 2008-03-11 1:04 David Chinner
2008-04-01 23:00 ` David Chinner
0 siblings, 1 reply; 6+ messages in thread
From: David Chinner @ 2008-03-11 1:04 UTC (permalink / raw)
To: xfs-dev; +Cc: xfs, haryadi, remzi
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.
--
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.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Review] Improve XFS error checking and propagation
2008-03-11 1:04 [Review] Improve XFS error checking and propagation David Chinner
@ 2008-04-01 23:00 ` David Chinner
2008-04-02 2:58 ` Niv Sardi
0 siblings, 1 reply; 6+ messages in thread
From: David Chinner @ 2008-04-01 23:00 UTC (permalink / raw)
To: David Chinner; +Cc: xfs-dev, xfs
ping?
On Tue, Mar 11, 2008 at 12:04:21PM +1100, David Chinner wrote:
> 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.
> --
> 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.
>
--
Dave Chinner
Principal Engineer
SGI Australian Software Group
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Review] Improve XFS error checking and propagation
2008-04-01 23:00 ` David Chinner
@ 2008-04-02 2:58 ` Niv Sardi
2008-04-02 4:07 ` David Chinner
0 siblings, 1 reply; 6+ messages in thread
From: Niv Sardi @ 2008-04-02 2:58 UTC (permalink / raw)
To: David Chinner; +Cc: xfs-dev, xfs
David Chinner <dgc@sgi.com> writes:
> On Tue, Mar 11, 2008 at 12:04:21PM +1100, David Chinner wrote:
>> 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,
--
Niv Sardi
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Review] Improve XFS error checking and propagation
2008-04-02 2:58 ` Niv Sardi
@ 2008-04-02 4:07 ` David Chinner
2008-04-02 4:31 ` Niv Sardi
0 siblings, 1 reply; 6+ messages in thread
From: David Chinner @ 2008-04-02 4:07 UTC (permalink / raw)
To: Niv Sardi; +Cc: David Chinner, xfs-dev, xfs
On Wed, Apr 02, 2008 at 01:58:09PM +1100, Niv Sardi wrote:
> David Chinner <dgc@sgi.com> writes:
> > On Tue, Mar 11, 2008 at 12:04:21PM +1100, David Chinner wrote:
> >> 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).
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 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
That patch doesn't have any calls to xfs_fs_cmn_err() in it. Can you
clarify, please?
> 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....
> 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
Which means?
> OK xfs-mustcheck-bdwrite.patch
> OK xfs-mustcheck-truncate-page.patch # might be incomplete
Incomplete in what way?
> EDITED xfs-mustcheck-dqflush.patch # slight style change/typo
Details?
> OK xfs-mustcheck-reset-sbqflags.patch
> OK xfs-mustcheck-quotaoff.patch
> EDITED xfs-mustcheck-inactive.patch # slight style change/typo
Details?
Cheers,
Dave.
--
Dave Chinner
Principal Engineer
SGI Australian Software Group
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Review] Improve XFS error checking and propagation
2008-04-02 4:07 ` David Chinner
@ 2008-04-02 4:31 ` Niv Sardi
2008-04-02 5:12 ` David Chinner
0 siblings, 1 reply; 6+ messages in thread
From: Niv Sardi @ 2008-04-02 4:31 UTC (permalink / raw)
To: David Chinner; +Cc: xfs-dev, xfs
David Chinner <dgc@sgi.com> writes:
> On Wed, Apr 02, 2008 at 01:58:09PM +1100, Niv Sardi wrote:
>> David Chinner <dgc@sgi.com> writes:
>> > On Tue, Mar 11, 2008 at 12:04:21PM +1100, David Chinner wrote:
>> >> 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).
>
> 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…
>> 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
>
> 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 void
as it didn't really make sense anymore.
>> 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.
>> 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
>
> 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 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 =)
>> 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.
>> OK xfs-mustcheck-reset-sbqflags.patch
>> OK xfs-mustcheck-quotaoff.patch
>> EDITED xfs-mustcheck-inactive.patch # slight style change/typo
>
> Details?
-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,
--
Niv Sardi
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Review] Improve XFS error checking and propagation
2008-04-02 4:31 ` Niv Sardi
@ 2008-04-02 5:12 ` David Chinner
0 siblings, 0 replies; 6+ messages in thread
From: David Chinner @ 2008-04-02 5:12 UTC (permalink / raw)
To: Niv Sardi; +Cc: David Chinner, xfs-dev, xfs
On Wed, Apr 02, 2008 at 03:31:37PM +1100, Niv Sardi wrote:
> David Chinner <dgc@sgi.com> writes:
>
> > On Wed, Apr 02, 2008 at 01:58:09PM +1100, Niv Sardi wrote:
> >> 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
> >
> > 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 void
>
> as it didn't really make sense anymore.
Ok, Fixed.
> >> 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
> >
> > 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....
> >> 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.
Oh, in the patch description....
> and xfs_fs_cmn_err stuff.
Same as above...
> >> OK xfs-mustcheck-reset-sbqflags.patch
> >> OK xfs-mustcheck-quotaoff.patch
> >> EDITED xfs-mustcheck-inactive.patch # slight style change/typo
> >
> > Details?
>
> -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.
--
Dave Chinner
Principal Engineer
SGI Australian Software Group
^ permalink raw reply [flat|nested] 6+ messages in thread
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2008-03-11 1:04 [Review] Improve XFS error checking and propagation David Chinner
2008-04-01 23:00 ` David Chinner
2008-04-02 2:58 ` Niv Sardi
2008-04-02 4:07 ` David Chinner
2008-04-02 4:31 ` Niv Sardi
2008-04-02 5:12 ` David Chinner
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