diff options
Diffstat (limited to 'fs/xfs/linux-2.6/xfs_sync.c')
| -rw-r--r-- | fs/xfs/linux-2.6/xfs_sync.c | 132 |
1 files changed, 15 insertions, 117 deletions
diff --git a/fs/xfs/linux-2.6/xfs_sync.c b/fs/xfs/linux-2.6/xfs_sync.c index 91a54a79a09b..ed24435af651 100644 --- a/fs/xfs/linux-2.6/xfs_sync.c +++ b/fs/xfs/linux-2.6/xfs_sync.c @@ -316,11 +316,21 @@ xfs_sync_fsdata( } /* - * First stage of freeze - no more writers will make progress now we are here, + * When remounting a filesystem read-only or freezing the filesystem, we have + * two phases to execute. This first phase is syncing the data before we + * quiesce the filesystem, and the second is flushing all the inodes out after + * we've waited for all the transactions created by the first phase to + * complete. The second phase ensures that the inodes are written to their + * location on disk rather than just existing in transactions in the log. This + * means after a quiesce there is no log replay required to write the inodes to + * disk (this is the main difference between a sync and a quiesce). + */ +/* + * First stage of freeze - no writers will make progress now we are here, * so we flush delwri and delalloc buffers here, then wait for all I/O to * complete. Data is frozen at that point. Metadata is not frozen, - * transactions can still occur here so don't bother flushing the buftarg (i.e - * SYNC_QUIESCE) because it'll just get dirty again. + * transactions can still occur here so don't bother flushing the buftarg + * because it'll just get dirty again. */ int xfs_quiesce_data( @@ -337,11 +347,10 @@ xfs_quiesce_data( xfs_sync_inodes(mp, SYNC_DELWRI|SYNC_WAIT|SYNC_IOWAIT); XFS_QM_DQSYNC(mp, SYNC_WAIT); - /* write superblock and hoover shutdown errors */ + /* write superblock and hoover up shutdown errors */ error = xfs_sync_fsdata(mp, 0); - /* flush devices */ - XFS_bflush(mp->m_ddev_targp); + /* flush data-only devices */ if (mp->m_rtdev_targp) XFS_bflush(mp->m_rtdev_targp); @@ -349,117 +358,6 @@ xfs_quiesce_data( } /* - * xfs_sync flushes any pending I/O to file system vfsp. - * - * This routine is called by vfs_sync() to make sure that things make it - * out to disk eventually, on sync() system calls to flush out everything, - * and when the file system is unmounted. For the vfs_sync() case, all - * we really need to do is sync out the log to make all of our meta-data - * updates permanent (except for timestamps). For calls from pflushd(), - * dirty pages are kept moving by calling pdflush() on the inodes - * containing them. We also flush the inodes that we can lock without - * sleeping and the superblock if we can lock it without sleeping from - * vfs_sync() so that items at the tail of the log are always moving out. - * - * Flags: - * SYNC_BDFLUSH - We're being called from vfs_sync() so we don't want - * to sleep if we can help it. All we really need - * to do is ensure that the log is synced at least - * periodically. We also push the inodes and - * superblock if we can lock them without sleeping - * and they are not pinned. - * SYNC_ATTR - We need to flush the inodes. Now handled by direct calls - * to xfs_sync_inodes(). - * SYNC_WAIT - All the flushes that take place in this call should - * be synchronous. - * SYNC_DELWRI - This tells us to push dirty pages associated with - * inodes. SYNC_WAIT and SYNC_BDFLUSH are used to - * determine if they should be flushed sync, async, or - * delwri. - * SYNC_FSDATA - This indicates that the caller would like to make - * sure the superblock is safe on disk. We can ensure - * this by simply making sure the log gets flushed - * if SYNC_BDFLUSH is set, and by actually writing it - * out otherwise. - * SYNC_IOWAIT - The caller wants us to wait for all data I/O to complete - * before we return (including direct I/O). Forms the drain - * side of the write barrier needed to safely quiesce the - * filesystem. - * - */ -int -xfs_sync( - xfs_mount_t *mp, - int flags) -{ - int error; - int last_error = 0; - uint log_flags = XFS_LOG_FORCE; - - ASSERT(!(flags & SYNC_ATTR)); - - /* - * Get the Quota Manager to flush the dquots. - * - * If XFS quota support is not enabled or this filesystem - * instance does not use quotas XFS_QM_DQSYNC will always - * return zero. - */ - error = XFS_QM_DQSYNC(mp, flags); - if (error) { - /* - * If we got an IO error, we will be shutting down. - * So, there's nothing more for us to do here. - */ - ASSERT(error != EIO || XFS_FORCED_SHUTDOWN(mp)); - if (XFS_FORCED_SHUTDOWN(mp)) - return XFS_ERROR(error); - } - - if (flags & SYNC_IOWAIT) - xfs_filestream_flush(mp); - - /* - * Sync out the log. This ensures that the log is periodically - * flushed even if there is not enough activity to fill it up. - */ - if (flags & SYNC_WAIT) - log_flags |= XFS_LOG_SYNC; - - xfs_log_force(mp, (xfs_lsn_t)0, log_flags); - - if (flags & SYNC_DELWRI) { - if (flags & SYNC_BDFLUSH) - xfs_finish_reclaim_all(mp, 1, XFS_IFLUSH_DELWRI_ELSE_ASYNC); - else - error = xfs_sync_inodes(mp, flags); - /* - * Flushing out dirty data above probably generated more - * log activity, so if this isn't vfs_sync() then flush - * the log again. - */ - xfs_log_force(mp, 0, log_flags); - } - - if (flags & SYNC_FSDATA) { - error = xfs_sync_fsdata(mp, flags); - if (error) - last_error = error; - } - - /* - * Now check to see if the log needs a "dummy" transaction. - */ - if (!(flags & SYNC_REMOUNT) && xfs_log_need_covered(mp)) { - error = xfs_commit_dummy_trans(mp, log_flags); - if (error) - return error; - } - - return XFS_ERROR(last_error); -} - -/* * Enqueue a work item to be picked up by the vfs xfssyncd thread. * Doing this has two advantages: * - It saves on stack space, which is tight in certain situations |