| Message ID | 20210106174127.805660-7-bfoster@redhat.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | xfs: rework log quiesce to cover the log | expand |
On Wed, Jan 06, 2021 at 12:41:24PM -0500, Brian Foster wrote: > xfs_log_sbcount() calls xfs_sync_sb() to sync superblock counters to > disk when lazy superblock accounting is enabled. This occurs on > unmount, freeze, and read-only (re)mount and ensures the final > values are calculated and persisted to disk before each form of > quiesce completes. > > Now that log covering occurs in all of these contexts and uses the > same xfs_sync_sb() mechanism to update log state, there is no need > to log the superblock separately for any reason. Update the log > quiesce path to sync the superblock at least once for any mount > where lazy superblock accounting is enabled. If the log is already > covered, it will remain in the covered state. Otherwise, the next > sync as part of the normal covering sequence will carry the > associated superblock update with it. Remove xfs_log_sbcount() now > that it is no longer needed. > > Signed-off-by: Brian Foster <bfoster@redhat.com> If all my previous ramblings were correct, Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> --D > --- > fs/xfs/xfs_log.c | 20 ++++++++++++++++++-- > fs/xfs/xfs_mount.c | 31 ------------------------------- > fs/xfs/xfs_mount.h | 1 - > fs/xfs/xfs_super.c | 8 -------- > 4 files changed, 18 insertions(+), 42 deletions(-) > > diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c > index 9b8564f280b7..83e2697d4e38 100644 > --- a/fs/xfs/xfs_log.c > +++ b/fs/xfs/xfs_log.c > @@ -1108,6 +1108,7 @@ xfs_log_cover( > { > struct xlog *log = mp->m_log; > int error = 0; > + bool need_covered; > > ASSERT((xlog_cil_empty(log) && xlog_iclogs_empty(log) && > !xfs_ail_min_lsn(log->l_ailp)) || > @@ -1116,6 +1117,21 @@ xfs_log_cover( > if (!xfs_log_writable(mp)) > return 0; > > + /* > + * xfs_log_need_covered() is not idempotent because it progresses the > + * state machine if the log requires covering. Therefore, we must call > + * this function once and use the result until we've issued an sb sync. > + * Do so first to make that abundantly clear. > + * > + * Fall into the covering sequence if the log needs covering or the > + * mount has lazy superblock accounting to sync to disk. The sb sync > + * used for covering accumulates the in-core counters, so covering > + * handles this for us. > + */ > + need_covered = xfs_log_need_covered(mp); > + if (!need_covered && !xfs_sb_version_haslazysbcount(&mp->m_sb)) > + return 0; > + > /* > * To cover the log, commit the superblock twice (at most) in > * independent checkpoints. The first serves as a reference for the > @@ -1125,12 +1141,12 @@ xfs_log_cover( > * covering the log. Push the AIL one more time to leave it empty, as > * we found it. > */ > - while (xfs_log_need_covered(mp)) { > + do { > error = xfs_sync_sb(mp, true); > if (error) > break; > xfs_ail_push_all_sync(mp->m_ail); > - } > + } while (xfs_log_need_covered(mp)); > > return error; > } > diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c > index a62b8a574409..f97b82d0e30f 100644 > --- a/fs/xfs/xfs_mount.c > +++ b/fs/xfs/xfs_mount.c > @@ -1124,12 +1124,6 @@ xfs_unmountfs( > xfs_warn(mp, "Unable to free reserved block pool. " > "Freespace may not be correct on next mount."); > > - error = xfs_log_sbcount(mp); > - if (error) > - xfs_warn(mp, "Unable to update superblock counters. " > - "Freespace may not be correct on next mount."); > - > - > xfs_log_unmount(mp); > xfs_da_unmount(mp); > xfs_uuid_unmount(mp); > @@ -1164,31 +1158,6 @@ xfs_fs_writable( > return true; > } > > -/* > - * xfs_log_sbcount > - * > - * Sync the superblock counters to disk. > - * > - * Note this code can be called during the process of freezing, so we use the > - * transaction allocator that does not block when the transaction subsystem is > - * in its frozen state. > - */ > -int > -xfs_log_sbcount(xfs_mount_t *mp) > -{ > - if (!xfs_log_writable(mp)) > - return 0; > - > - /* > - * we don't need to do this if we are updating the superblock > - * counters on every modification. > - */ > - if (!xfs_sb_version_haslazysbcount(&mp->m_sb)) > - return 0; > - > - return xfs_sync_sb(mp, true); > -} > - > /* > * Deltas for the block count can vary from 1 to very large, but lock contention > * only occurs on frequent small block count updates such as in the delayed > diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h > index dfa429b77ee2..452ca7654dc5 100644 > --- a/fs/xfs/xfs_mount.h > +++ b/fs/xfs/xfs_mount.h > @@ -399,7 +399,6 @@ int xfs_buf_hash_init(xfs_perag_t *pag); > void xfs_buf_hash_destroy(xfs_perag_t *pag); > > extern void xfs_uuid_table_free(void); > -extern int xfs_log_sbcount(xfs_mount_t *); > extern uint64_t xfs_default_resblks(xfs_mount_t *mp); > extern int xfs_mountfs(xfs_mount_t *mp); > extern int xfs_initialize_perag(xfs_mount_t *mp, xfs_agnumber_t agcount, > diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c > index 09d956e30fd8..75ada867c665 100644 > --- a/fs/xfs/xfs_super.c > +++ b/fs/xfs/xfs_super.c > @@ -884,19 +884,11 @@ void > xfs_quiesce_attr( > struct xfs_mount *mp) > { > - int error = 0; > - > cancel_delayed_work_sync(&mp->m_log->l_work); > > /* force the log to unpin objects from the now complete transactions */ > xfs_log_force(mp, XFS_LOG_SYNC); > > - > - /* Push the superblock and write an unmount record */ > - error = xfs_log_sbcount(mp); > - if (error) > - xfs_warn(mp, "xfs_attr_quiesce: failed to log sb changes. " > - "Frozen image may not be consistent."); > xfs_log_clean(mp); > } > > -- > 2.26.2 >
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 9b8564f280b7..83e2697d4e38 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -1108,6 +1108,7 @@ xfs_log_cover( { struct xlog *log = mp->m_log; int error = 0; + bool need_covered; ASSERT((xlog_cil_empty(log) && xlog_iclogs_empty(log) && !xfs_ail_min_lsn(log->l_ailp)) || @@ -1116,6 +1117,21 @@ xfs_log_cover( if (!xfs_log_writable(mp)) return 0; + /* + * xfs_log_need_covered() is not idempotent because it progresses the + * state machine if the log requires covering. Therefore, we must call + * this function once and use the result until we've issued an sb sync. + * Do so first to make that abundantly clear. + * + * Fall into the covering sequence if the log needs covering or the + * mount has lazy superblock accounting to sync to disk. The sb sync + * used for covering accumulates the in-core counters, so covering + * handles this for us. + */ + need_covered = xfs_log_need_covered(mp); + if (!need_covered && !xfs_sb_version_haslazysbcount(&mp->m_sb)) + return 0; + /* * To cover the log, commit the superblock twice (at most) in * independent checkpoints. The first serves as a reference for the @@ -1125,12 +1141,12 @@ xfs_log_cover( * covering the log. Push the AIL one more time to leave it empty, as * we found it. */ - while (xfs_log_need_covered(mp)) { + do { error = xfs_sync_sb(mp, true); if (error) break; xfs_ail_push_all_sync(mp->m_ail); - } + } while (xfs_log_need_covered(mp)); return error; } diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c index a62b8a574409..f97b82d0e30f 100644 --- a/fs/xfs/xfs_mount.c +++ b/fs/xfs/xfs_mount.c @@ -1124,12 +1124,6 @@ xfs_unmountfs( xfs_warn(mp, "Unable to free reserved block pool. " "Freespace may not be correct on next mount."); - error = xfs_log_sbcount(mp); - if (error) - xfs_warn(mp, "Unable to update superblock counters. " - "Freespace may not be correct on next mount."); - - xfs_log_unmount(mp); xfs_da_unmount(mp); xfs_uuid_unmount(mp); @@ -1164,31 +1158,6 @@ xfs_fs_writable( return true; } -/* - * xfs_log_sbcount - * - * Sync the superblock counters to disk. - * - * Note this code can be called during the process of freezing, so we use the - * transaction allocator that does not block when the transaction subsystem is - * in its frozen state. - */ -int -xfs_log_sbcount(xfs_mount_t *mp) -{ - if (!xfs_log_writable(mp)) - return 0; - - /* - * we don't need to do this if we are updating the superblock - * counters on every modification. - */ - if (!xfs_sb_version_haslazysbcount(&mp->m_sb)) - return 0; - - return xfs_sync_sb(mp, true); -} - /* * Deltas for the block count can vary from 1 to very large, but lock contention * only occurs on frequent small block count updates such as in the delayed diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h index dfa429b77ee2..452ca7654dc5 100644 --- a/fs/xfs/xfs_mount.h +++ b/fs/xfs/xfs_mount.h @@ -399,7 +399,6 @@ int xfs_buf_hash_init(xfs_perag_t *pag); void xfs_buf_hash_destroy(xfs_perag_t *pag); extern void xfs_uuid_table_free(void); -extern int xfs_log_sbcount(xfs_mount_t *); extern uint64_t xfs_default_resblks(xfs_mount_t *mp); extern int xfs_mountfs(xfs_mount_t *mp); extern int xfs_initialize_perag(xfs_mount_t *mp, xfs_agnumber_t agcount, diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index 09d956e30fd8..75ada867c665 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -884,19 +884,11 @@ void xfs_quiesce_attr( struct xfs_mount *mp) { - int error = 0; - cancel_delayed_work_sync(&mp->m_log->l_work); /* force the log to unpin objects from the now complete transactions */ xfs_log_force(mp, XFS_LOG_SYNC); - - /* Push the superblock and write an unmount record */ - error = xfs_log_sbcount(mp); - if (error) - xfs_warn(mp, "xfs_attr_quiesce: failed to log sb changes. " - "Frozen image may not be consistent."); xfs_log_clean(mp); }
xfs_log_sbcount() calls xfs_sync_sb() to sync superblock counters to disk when lazy superblock accounting is enabled. This occurs on unmount, freeze, and read-only (re)mount and ensures the final values are calculated and persisted to disk before each form of quiesce completes. Now that log covering occurs in all of these contexts and uses the same xfs_sync_sb() mechanism to update log state, there is no need to log the superblock separately for any reason. Update the log quiesce path to sync the superblock at least once for any mount where lazy superblock accounting is enabled. If the log is already covered, it will remain in the covered state. Otherwise, the next sync as part of the normal covering sequence will carry the associated superblock update with it. Remove xfs_log_sbcount() now that it is no longer needed. Signed-off-by: Brian Foster <bfoster@redhat.com> --- fs/xfs/xfs_log.c | 20 ++++++++++++++++++-- fs/xfs/xfs_mount.c | 31 ------------------------------- fs/xfs/xfs_mount.h | 1 - fs/xfs/xfs_super.c | 8 -------- 4 files changed, 18 insertions(+), 42 deletions(-)