xfs: remove wrapper for the fsync file operation

Currently the fsync file operation is divided into a low-level
routine doing all the work and one that implements the Linux file
operation and does minimal argument wrapping.  This is a leftover
from the days of the vnode operations layer and can be removed to
simplify the code a bit, as well as preparing for the implementation
of an optimized fdatasync which needs to look at the Linux inode
state.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>

1 files changed, 117 insertions, 23 deletions

diff --git a/fs/xfs/linux-2.6/xfs_file.c b/fs/xfs/linux-2.6/xfs_file.c
index 1eb561a10e26..6c283b7be8ab 100644
--- a/fs/xfs/linux-2.6/xfs_file.c
+++ b/fs/xfs/linux-2.6/xfs_file.c
@@ -35,6 +35,7 @@
 #include "xfs_dir2_sf.h"
 #include "xfs_dinode.h"
 #include "xfs_inode.h"
+#include "xfs_inode_item.h"
 #include "xfs_bmap.h"
 #include "xfs_error.h"
 #include "xfs_rw.h"
@@ -96,6 +97,120 @@ xfs_iozero(
 	return (-status);
 }
 
+/*
+ * We ignore the datasync flag here because a datasync is effectively
+ * identical to an fsync. That is, datasync implies that we need to write
+ * only the metadata needed to be able to access the data that is written
+ * if we crash after the call completes. Hence if we are writing beyond
+ * EOF we have to log the inode size change as well, which makes it a
+ * full fsync. If we don't write beyond EOF, the inode core will be
+ * clean in memory and so we don't need to log the inode, just like
+ * fsync.
+ */
+STATIC int
+xfs_file_fsync(
+	struct file		*file,
+	struct dentry		*dentry,
+	int			datasync)
+{
+	struct xfs_inode	*ip = XFS_I(dentry->d_inode);
+	struct xfs_trans	*tp;
+	int			error = 0;
+	int			log_flushed = 0;
+
+	xfs_itrace_entry(ip);
+
+	if (XFS_FORCED_SHUTDOWN(ip->i_mount))
+		return -XFS_ERROR(EIO);
+
+	xfs_iflags_clear(ip, XFS_ITRUNCATED);
+
+	/*
+	 * We always need to make sure that the required inode state is safe on
+	 * disk.  The inode might be clean but we still might need to force the
+	 * log because of committed transactions that haven't hit the disk yet.
+	 * Likewise, there could be unflushed non-transactional changes to the
+	 * inode core that have to go to disk and this requires us to issue
+	 * a synchronous transaction to capture these changes correctly.
+	 *
+	 * This code relies on the assumption that if the i_update_core field
+	 * of the inode is clear and the inode is unpinned then it is clean
+	 * and no action is required.
+	 */
+	xfs_ilock(ip, XFS_ILOCK_SHARED);
+
+	if (ip->i_update_core) {
+		/*
+		 * Kick off a transaction to log the inode core to get the
+		 * updates.  The sync transaction will also force the log.
+		 */
+		xfs_iunlock(ip, XFS_ILOCK_SHARED);
+		tp = xfs_trans_alloc(ip->i_mount, XFS_TRANS_FSYNC_TS);
+		error = xfs_trans_reserve(tp, 0,
+				XFS_FSYNC_TS_LOG_RES(ip->i_mount), 0, 0, 0);
+		if (error) {
+			xfs_trans_cancel(tp, 0);
+			return -error;
+		}
+		xfs_ilock(ip, XFS_ILOCK_EXCL);
+
+		/*
+		 * Note - it's possible that we might have pushed ourselves out
+		 * of the way during trans_reserve which would flush the inode.
+		 * But there's no guarantee that the inode buffer has actually
+		 * gone out yet (it's delwri).	Plus the buffer could be pinned
+		 * anyway if it's part of an inode in another recent
+		 * transaction.	 So we play it safe and fire off the
+		 * transaction anyway.
+		 */
+		xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
+		xfs_trans_ihold(tp, ip);
+		xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+		xfs_trans_set_sync(tp);
+		error = _xfs_trans_commit(tp, 0, &log_flushed);
+
+		xfs_iunlock(ip, XFS_ILOCK_EXCL);
+	} else {
+		/*
+		 * Timestamps/size haven't changed since last inode flush or
+		 * inode transaction commit.  That means either nothing got
+		 * written or a transaction committed which caught the updates.
+		 * If the latter happened and the transaction hasn't hit the
+		 * disk yet, the inode will be still be pinned.  If it is,
+		 * force the log.
+		 */
+		xfs_iunlock(ip, XFS_ILOCK_SHARED);
+		if (xfs_ipincount(ip)) {
+			if (ip->i_itemp->ili_last_lsn) {
+				error = _xfs_log_force_lsn(ip->i_mount,
+						ip->i_itemp->ili_last_lsn,
+						XFS_LOG_SYNC, &log_flushed);
+			} else {
+				error = _xfs_log_force(ip->i_mount,
+						XFS_LOG_SYNC, &log_flushed);
+			}
+		}
+	}
+
+	if (ip->i_mount->m_flags & XFS_MOUNT_BARRIER) {
+		/*
+		 * If the log write didn't issue an ordered tag we need
+		 * to flush the disk cache for the data device now.
+		 */
+		if (!log_flushed)
+			xfs_blkdev_issue_flush(ip->i_mount->m_ddev_targp);
+
+		/*
+		 * If this inode is on the RT dev we need to flush that
+		 * cache as well.
+		 */
+		if (XFS_IS_REALTIME_INODE(ip))
+			xfs_blkdev_issue_flush(ip->i_mount->m_rtdev_targp);
+	}
+
+	return -error;
+}
+
 STATIC ssize_t
 xfs_file_aio_read(
 	struct kiocb		*iocb,
@@ -755,7 +870,8 @@ write_retry:
 			mutex_lock(&inode->i_mutex);
 		xfs_ilock(ip, iolock);
 
-		error2 = xfs_fsync(ip);
+		error2 = -xfs_file_fsync(file, file->f_path.dentry,
+					 (file->f_flags & __O_SYNC) ? 0 : 1);
 		if (!error)
 			error = error2;
 	}
@@ -826,28 +942,6 @@ xfs_file_release(
 	return -xfs_release(XFS_I(inode));
 }
 
-/*
- * We ignore the datasync flag here because a datasync is effectively
- * identical to an fsync. That is, datasync implies that we need to write
- * only the metadata needed to be able to access the data that is written
- * if we crash after the call completes. Hence if we are writing beyond
- * EOF we have to log the inode size change as well, which makes it a
- * full fsync. If we don't write beyond EOF, the inode core will be
- * clean in memory and so we don't need to log the inode, just like
- * fsync.
- */
-STATIC int
-xfs_file_fsync(
-	struct file		*file,
-	struct dentry		*dentry,
-	int			datasync)
-{
-	struct xfs_inode	*ip = XFS_I(dentry->d_inode);
-
-	xfs_iflags_clear(ip, XFS_ITRUNCATED);
-	return -xfs_fsync(ip);
-}
-
 STATIC int
 xfs_file_readdir(
 	struct file	*filp,