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| author | Dave Chinner <dchinner@redhat.com> | 2015-01-22 09:10:26 +1100 |
|---|---|---|
| committer | Dave Chinner <david@fromorbit.com> | 2015-01-22 09:10:26 +1100 |
| commit | 4d11a40239405e531fc0e9dcd07921f00b965931 (patch) | |
| tree | f8a6b43d76e4d698f7cb1a5daf9027d2a2f22ca7 /fs/xfs/xfs_qm_syscalls.c | |
| parent | 97bf6af1f928216fd6c5a66e8a57bfa95a659672 (diff) | |
| download | linux-4d11a40239405e531fc0e9dcd07921f00b965931.tar.gz | |
xfs: remove bitfield based superblock updates
When we log changes to the superblock, we first have to write them to the on-disk buffer, and then log that. Right now we have a complex bitfield based arrangement to only write the modified field to the buffer before we log it. This used to be necessary as a performance optimisation because we logged the superblock buffer in every extent or inode allocation or freeing, and so performance was extremely important. We haven't done this for years, however, ever since the lazy superblock counters pulled the superblock logging out of the transaction commit fast path. Hence we have a bunch of complexity that is not necessary that makes writing the in-core superblock to disk much more complex than it needs to be. We only need to log the superblock now during management operations (e.g. during mount, unmount or quota control operations) so it is not a performance critical path anymore. As such, remove the complex field based logging mechanism and replace it with a simple conversion function similar to what we use for all other on-disk structures. This means we always log the entirity of the superblock, but again because we rarely modify the superblock this is not an issue for log bandwidth or CPU time. Indeed, if we do log the superblock frequently, delayed logging will minimise the impact of this overhead. [Fixed gquota/pquota inode sharing regression noticed by bfoster.] Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
Diffstat (limited to 'fs/xfs/xfs_qm_syscalls.c')
| -rw-r--r-- | fs/xfs/xfs_qm_syscalls.c | 13 |
1 files changed, 4 insertions, 9 deletions
diff --git a/fs/xfs/xfs_qm_syscalls.c b/fs/xfs/xfs_qm_syscalls.c index 74fca68e43b6..8d7e5f068803 100644 --- a/fs/xfs/xfs_qm_syscalls.c +++ b/fs/xfs/xfs_qm_syscalls.c @@ -92,8 +92,7 @@ xfs_qm_scall_quotaoff( mutex_unlock(&q->qi_quotaofflock); /* XXX what to do if error ? Revert back to old vals incore ? */ - error = xfs_qm_write_sb_changes(mp, XFS_SB_QFLAGS); - return error; + return xfs_qm_write_sb_changes(mp); } dqtype = 0; @@ -314,7 +313,6 @@ xfs_qm_scall_quotaon( { int error; uint qf; - __int64_t sbflags; flags &= (XFS_ALL_QUOTA_ACCT | XFS_ALL_QUOTA_ENFD); /* @@ -322,8 +320,6 @@ xfs_qm_scall_quotaon( */ flags &= ~(XFS_ALL_QUOTA_ACCT); - sbflags = 0; - if (flags == 0) { xfs_debug(mp, "%s: zero flags, m_qflags=%x", __func__, mp->m_qflags); @@ -370,11 +366,10 @@ xfs_qm_scall_quotaon( /* * There's nothing to change if it's the same. */ - if ((qf & flags) == flags && sbflags == 0) + if ((qf & flags) == flags) return -EEXIST; - sbflags |= XFS_SB_QFLAGS; - if ((error = xfs_qm_write_sb_changes(mp, sbflags))) + if ((error = xfs_qm_write_sb_changes(mp))) return error; /* * If we aren't trying to switch on quota enforcement, we are done. @@ -801,7 +796,7 @@ xfs_qm_log_quotaoff( mp->m_sb.sb_qflags = (mp->m_qflags & ~(flags)) & XFS_MOUNT_QUOTA_ALL; spin_unlock(&mp->m_sb_lock); - xfs_mod_sb(tp, XFS_SB_QFLAGS); + xfs_mod_sb(tp); /* * We have to make sure that the transaction is secure on disk before we |