[PATCH 16/28] XFS: Kill xfs_sync()

Dave Chinner
2008-08-19T13:16:24Z

There are no more callers to xfs_sync() now, so remove the
function altogther.

Signed-off-by: Dave Chinner <david@fromorbit.com>
---
fs/xfs/linux-2.6/xfs_sync.c | 132 +++++--------------------------------------
fs/xfs/linux-2.6/xfs_sync.h | 25 +-------
fs/xfs/quota/xfs_qm.c | 10 +--
fs/xfs/xfs_iget.c | 15 ++---
4 files changed, 29 insertions(+), 153 deletions(-)

diff --git a/fs/xfs/linux-2.6/xfs_sync.c b/fs/xfs/linux-2.6/xfs_sync.c
index f9b0816..c134cad 100644
--- a/fs/xfs/linux-2.6/xfs_sync.c
+++ b/fs/xfs/linux-2.6/xfs_sync.c
@@ -309,11 +309,21 @@ 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(
@@ -332,11 +342,10 @@ xfs_quiesce_data(
xfs_log_force(mp, 0, XFS_LOG_FORCE|XFS_LOG_SYNC);
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);

@@ -344,117 +353,6 @@ 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
diff --git a/fs/xfs/linux-2.6/xfs_sync.h b/fs/xfs/linux-2.6/xfs_sync.h
index 2509db0..4591dc0 100644
--- a/fs/xfs/linux-2.6/xfs_sync.h
+++ b/fs/xfs/linux-2.6/xfs_sync.h
@@ -28,31 +28,14 @@ typedef struct bhv_vfs_sync_work {
} bhv_vfs_sync_work_t;

#define SYNC_ATTR 0x0001 /* sync attributes */
-#define SYNC_DELWRI 0x0004 /* look at delayed writes */
-#define SYNC_WAIT 0x0008 /* wait for i/o to complete */
-#define SYNC_BDFLUSH 0x0010 /* BDFLUSH is calling -- don't block */
-#define SYNC_FSDATA 0x0020 /* flush fs data (e.g. superblocks) */
-#define SYNC_REFCACHE 0x0040 /* prune some of the nfs ref cache */
-#define SYNC_REMOUNT 0x0080 /* remount readonly, no dummy LRs */
-#define SYNC_IOWAIT 0x0100 /* wait for all I/O to complete */
-
-/*
- * 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 fielsystem, 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 uses SYNC_INODE_QUIESCE
- * to ensure 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).
- */
-#define SYNC_DATA_QUIESCE (SYNC_DELWRI|SYNC_FSDATA|SYNC_WAIT|SYNC_IOWAIT)
+#define SYNC_DELWRI 0x0002 /* look at delayed writes */
+#define SYNC_WAIT 0x0004 /* wait for i/o to complete */
+#define SYNC_BDFLUSH 0x0008 /* BDFLUSH is calling -- don't block */
+#define SYNC_IOWAIT 0x0010 /* wait for all I/O to complete */

int xfs_syncd_init(struct xfs_mount *mp);
void xfs_syncd_stop(struct xfs_mount *mp);

-int xfs_sync(struct xfs_mount *mp, int flags);
int xfs_sync_inodes(struct xfs_mount *mp, int flags);
int xfs_sync_fsdata(struct xfs_mount *mp, int flags);

diff --git a/fs/xfs/quota/xfs_qm.c b/fs/xfs/quota/xfs_qm.c
index df0ffef..46465e7 100644
--- a/fs/xfs/quota/xfs_qm.c
+++ b/fs/xfs/quota/xfs_qm.c
@@ -987,14 +987,10 @@ xfs_qm_dqdetach(
}

/*
- * This is called by VFS_SYNC and flags arg determines the caller,
- * and its motives, as done in xfs_sync.
- *
- * vfs_sync: SYNC_FSDATA|SYNC_ATTR|SYNC_BDFLUSH 0x31
- * syscall sync: SYNC_FSDATA|SYNC_ATTR|SYNC_DELWRI 0x25
- * umountroot : SYNC_WAIT | SYNC_CLOSE | SYNC_ATTR | SYNC_FSDATA
+ * This is called to sync quotas. We can be told to use non-blocking
+ * semantics by either the SYNC_BDFLUSH flag or the absence of the
+ * SYNC_WAIT flag.
*/
-
int
xfs_qm_sync(
xfs_mount_t *mp,
diff --git a/fs/xfs/xfs_iget.c b/fs/xfs/xfs_iget.c
index 60554ce..7932551 100644
--- a/fs/xfs/xfs_iget.c
+++ b/fs/xfs/xfs_iget.c
@@ -443,14 +443,13 @@ xfs_ireclaim(xfs_inode_t *ip)
xfs_iextract(ip);

/*
- * Here we do a spurious inode lock in order to coordinate with
- * xfs_sync(). This is because xfs_sync() references the inodes
- * in the mount list without taking references on the corresponding
- * vnodes. We make that OK here by ensuring that we wait until
- * the inode is unlocked in xfs_sync() before we go ahead and
- * free it. We get both the regular lock and the io lock because
- * the xfs_sync() code may need to drop the regular one but will
- * still hold the io lock.
+ * Here we do a spurious inode lock in order to coordinate with inode
+ * cache radix tree lookups. This is because the lookup can reference
+ * the inodes in the cache without taking references. We make that OK
+ * here by ensuring that we wait until the inode is unlocked after the
+ * lookup before we go ahead and free it. We get both the ilock and
+ * the iolock because the code may need to drop the ilock one but will
+ * still hold the iolock.
*/
xfs_ilock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);

--
1.5.6