[PATCH 1/6] xfs: preallocation transactions do not need to be synchronous

Dave Chinner
2011-03-23T06:12:41Z

From: Dave Chinner <dchinner@redhat.com>

Preallocation and hole punch transactions are currently synchronous
and this is causing performance problems in some cases. The
transactions don't need to be synchronous as we don't need to
guarantee the preallocation is persistent on disk until a
fdatasync, fsync, sync operation occurs. If the file is opened
O_SYNC or O_DATASYNC, only then should the transaction be issued
synchronously.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/linux-2.6/xfs_file.c | 4 ++++
fs/xfs/linux-2.6/xfs_ioctl.c | 4 ++++
fs/xfs/xfs_vnodeops.c | 3 ++-
fs/xfs/xfs_vnodeops.h | 1 +
4 files changed, 11 insertions(+), 1 deletions(-)

diff --git a/fs/xfs/linux-2.6/xfs_file.c b/fs/xfs/linux-2.6/xfs_file.c
index ae59865..baa2cb3 100644
--- a/fs/xfs/linux-2.6/xfs_file.c
+++ b/fs/xfs/linux-2.6/xfs_file.c
@@ -896,6 +896,7 @@ xfs_file_fallocate(
xfs_flock64_t bf;
xfs_inode_t *ip = XFS_I(inode);
int cmd = XFS_IOC_RESVSP;
+ int attr_flags = XFS_ATTR_NOLOCK;

if (mode & ~(FALLOC_FL_KEEP_SIZE |
FALLOC_FL_PUNCH_HOLE |
@@ -922,6 +923,9 @@ xfs_file_fallocate(
goto out_unlock;
}

+ if (file->f_flags & O_DSYNC)
+ attr_flags |= XFS_ATTR_SYNC;
+
error = -xfs_change_file_space(ip, cmd, &bf, 0, XFS_ATTR_NOLOCK);
if (error)
goto out_unlock;
diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c
index 0ca0e3c..acca2c5 100644
--- a/fs/xfs/linux-2.6/xfs_ioctl.c
+++ b/fs/xfs/linux-2.6/xfs_ioctl.c
@@ -624,6 +624,10 @@ xfs_ioc_space(

if (filp->f_flags & (O_NDELAY|O_NONBLOCK))
attr_flags |= XFS_ATTR_NONBLOCK;
+
+ if (filp->f_flags & O_DSYNC)
+ attr_flags |= XFS_ATTR_SYNC;
+
if (ioflags & IO_INVIS)
attr_flags |= XFS_ATTR_DMI;

diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 37d8146..c48b421 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -2831,7 +2831,8 @@ xfs_change_file_space(
ip->i_d.di_flags &= ~XFS_DIFLAG_PREALLOC;

xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
- xfs_trans_set_sync(tp);
+ if (attr_flags & XFS_ATTR_SYNC)
+ xfs_trans_set_sync(tp);

error = xfs_trans_commit(tp, 0);

diff --git a/fs/xfs/xfs_vnodeops.h b/fs/xfs/xfs_vnodeops.h
index f6702927..3bcd233 100644
--- a/fs/xfs/xfs_vnodeops.h
+++ b/fs/xfs/xfs_vnodeops.h
@@ -18,6 +18,7 @@ int xfs_setattr(struct xfs_inode *ip, struct iattr *vap, int flags);
#define XFS_ATTR_NONBLOCK 0x02 /* return EAGAIN if operation would block */
#define XFS_ATTR_NOLOCK 0x04 /* Don't grab any conflicting locks */
#define XFS_ATTR_NOACL 0x08 /* Don't call xfs_acl_chmod */
+#define XFS_ATTR_SYNC 0x10 /* synchronous operation required */

int xfs_readlink(struct xfs_inode *ip, char *link);
int xfs_release(struct xfs_inode *ip);
--
1.7.2.3