Add O_SYNC support to btrfs_file_write
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 9260d34..843e920 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -635,8 +635,9 @@
size_t count, loff_t *ppos)
{
loff_t pos;
- size_t num_written = 0;
- int err = 0;
+ loff_t start_pos;
+ ssize_t num_written = 0;
+ ssize_t err = 0;
int ret = 0;
struct inode *inode = file->f_path.dentry->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
@@ -652,7 +653,10 @@
pinned[1] = NULL;
if (file->f_flags & O_DIRECT)
return -EINVAL;
+
pos = *ppos;
+ start_pos = pos;
+
vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
current->backing_dev_info = inode->i_mapping->backing_dev_info;
err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
@@ -743,6 +747,13 @@
if (pinned[1])
page_cache_release(pinned[1]);
*ppos = pos;
+
+ if (num_written > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
+ err = sync_page_range(inode, inode->i_mapping,
+ start_pos, num_written);
+ if (err < 0)
+ num_written = err;
+ }
current->backing_dev_info = NULL;
return num_written ? num_written : err;
}