xfs: merge fsync and O_SYNC handling
The guarantees for O_SYNC are exactly the same as the ones we need to
make for an fsync call (and given that Linux O_SYNC is O_DSYNC the
equivalent is fdadatasync, but we treat both the same in XFS), except
with a range data writeout. Jan Kara has started unifying these two
path for filesystems using the generic helpers, and I've started to
look at XFS.
The actual transaction commited by xfs_fsync and xfs_write_sync_logforce
has a different transaction number, but actually is exactly the same.
We'll only use the fsync transaction going forward. One major difference
is that xfs_write_sync_logforce never issues a cache flush unless we
commit a transaction causing that as a side-effect, which is an obvious
bug in the O_SYNC handling. Second all the locking and i_update_size
vs i_update_core changes from 978b7237123d007b9fa983af6e0e2fa8f97f9934
never made it to xfs_write_sync_logforce, so we add them back.
To make xfs_fsync easily usable from the O_SYNC path, the filemap_fdatawait
call is moved up to xfs_file_fsync, so that we don't wait on the whole
file after we already waited for our portion in xfs_write.
We'll also use a plain call to filemap_write_and_wait_range instead
of the previous sync_page_rang which did it in two steps including
an half-hearted inode write out that doesn't help us.
Once we're done with this also remove the now useless i_update_size
tracking.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c
index aecf251..d5e5559 100644
--- a/fs/xfs/linux-2.6/xfs_aops.c
+++ b/fs/xfs/linux-2.6/xfs_aops.c
@@ -216,7 +216,6 @@
if (ip->i_d.di_size < isize) {
ip->i_d.di_size = isize;
ip->i_update_core = 1;
- ip->i_update_size = 1;
xfs_mark_inode_dirty_sync(ip);
}
diff --git a/fs/xfs/linux-2.6/xfs_file.c b/fs/xfs/linux-2.6/xfs_file.c
index 0542fd5..988d8f8 100644
--- a/fs/xfs/linux-2.6/xfs_file.c
+++ b/fs/xfs/linux-2.6/xfs_file.c
@@ -172,12 +172,21 @@
*/
STATIC int
xfs_file_fsync(
- struct file *filp,
- struct dentry *dentry,
- int datasync)
+ struct file *file,
+ struct dentry *dentry,
+ int datasync)
{
- xfs_iflags_clear(XFS_I(dentry->d_inode), XFS_ITRUNCATED);
- return -xfs_fsync(XFS_I(dentry->d_inode));
+ struct inode *inode = dentry->d_inode;
+ struct xfs_inode *ip = XFS_I(inode);
+ int error;
+
+ /* capture size updates in I/O completion before writing the inode. */
+ error = filemap_fdatawait(inode->i_mapping);
+ if (error)
+ return error;
+
+ xfs_iflags_clear(ip, XFS_ITRUNCATED);
+ return -xfs_fsync(ip);
}
STATIC int
diff --git a/fs/xfs/linux-2.6/xfs_lrw.c b/fs/xfs/linux-2.6/xfs_lrw.c
index 7078974..49e4a6a 100644
--- a/fs/xfs/linux-2.6/xfs_lrw.c
+++ b/fs/xfs/linux-2.6/xfs_lrw.c
@@ -812,18 +812,21 @@
/* Handle various SYNC-type writes */
if ((file->f_flags & O_SYNC) || IS_SYNC(inode)) {
+ loff_t end = pos + ret - 1;
int error2;
xfs_iunlock(xip, iolock);
if (need_i_mutex)
mutex_unlock(&inode->i_mutex);
- error2 = sync_page_range(inode, mapping, pos, ret);
+
+ error2 = filemap_write_and_wait_range(mapping, pos, end);
if (!error)
error = error2;
if (need_i_mutex)
mutex_lock(&inode->i_mutex);
xfs_ilock(xip, iolock);
- error2 = xfs_write_sync_logforce(mp, xip);
+
+ error2 = xfs_fsync(xip);
if (!error)
error = error2;
}