fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers

Btrfs needs to be able to control how filemap_write_and_wait_range() is called
in fsync to make it less of a painful operation, so push down taking i_mutex and
the calling of filemap_write_and_wait() down into the ->fsync() handlers.  Some
file systems can drop taking the i_mutex altogether it seems, like ext3 and
ocfs2.  For correctness sake I just pushed everything down in all cases to make
sure that we keep the current behavior the same for everybody, and then each
individual fs maintainer can make up their mind about what to do from there.
Thanks,

Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 7 insertions, 2 deletions

diff --git a/fs/hpfs/file.c b/fs/hpfs/file.c
index 89c500ee5213..89d2a5803ae3 100644
--- a/fs/hpfs/file.c
+++ b/fs/hpfs/file.c
@@ -18,9 +18,14 @@ static int hpfs_file_release(struct inode *inode, struct file *file)
         return 0;
 }
 
-int hpfs_file_fsync(struct file *file, int datasync)
+int hpfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 {
         struct inode *inode = file->f_mapping->host;
+        int ret;
+
+        ret = filemap_write_and_wait_range(file->f_mapping, start, end);
+        if (ret)
+                return ret;
         return sync_blockdev(inode->i_sb->s_bdev);
 }
 
diff --git a/fs/hpfs/hpfs_fn.h b/fs/hpfs/hpfs_fn.h
index dd552f862c8f..331b5e234ef3 100644
--- a/fs/hpfs/hpfs_fn.h
+++ b/fs/hpfs/hpfs_fn.h
@@ -258,7 +258,7 @@ void hpfs_set_ea(struct inode *, struct fnode *, const char *,
 
 /* file.c */
 
-int hpfs_file_fsync(struct file *, int);
+int hpfs_file_fsync(struct file *, loff_t, loff_t, int);
 extern const struct file_operations hpfs_file_ops;
 extern const struct inode_operations hpfs_file_iops;
 extern const struct address_space_operations hpfs_aops;