diff options
author | Brian Behlendorf <[email protected]> | 2021-11-07 13:27:44 -0800 |
---|---|---|
committer | Tony Hutter <[email protected]> | 2021-11-05 08:08:55 -0700 |
commit | 664d487a5dbd758216ac613934a4080fcc1de347 (patch) | |
tree | ecd0b7b292537ca1525155439e4fc3433a199a0e /man | |
parent | 5bf81fea2f899520f2015d2982072f64b7428f71 (diff) |
Fix lseek(SEEK_DATA/SEEK_HOLE) mmap consistency
When using lseek(2) to report data/holes memory mapped regions of
the file were ignored. This could result in incorrect results.
To handle this zfs_holey_common() was updated to asynchronously
writeback any dirty mmap(2) regions prior to reporting holes.
Additionally, while not strictly required, the dn_struct_rwlock is
now held over the dirty check to prevent the dnode structure from
changing. This ensures that a clean dnode can't be dirtied before
the data/hole is located. The range lock is now also taken to
ensure the call cannot race with zfs_write().
Furthermore, the code was refactored to provide a dnode_is_dirty()
helper function which checks the dnode for any dirty records to
determine its dirtiness.
Reviewed-by: Matthew Ahrens <[email protected]>
Reviewed-by: Tony Hutter <[email protected]>
Reviewed-by: Rich Ercolani <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Issue #11900
Closes #12724
Diffstat (limited to 'man')
-rw-r--r-- | man/man4/zfs.4 | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/man/man4/zfs.4 b/man/man4/zfs.4 index 2aed68957..20b24d898 100644 --- a/man/man4/zfs.4 +++ b/man/man4/zfs.4 @@ -1574,7 +1574,7 @@ Allow no-operation writes. The occurrence of nopwrites will further depend on other pool properties .Pq i.a. the checksumming and compression algorithms . . -.It Sy zfs_dmu_offset_next_sync Ns = Ns Sy 0 Ns | ns 1 Pq int +.It Sy zfs_dmu_offset_next_sync Ns = Ns Sy 0 Ns | Ns 1 Pq int Enable forcing TXG sync to find holes. When enabled forces ZFS to act like prior versions when .Sy SEEK_HOLE No or Sy SEEK_DATA |