fs: always maintain i_dio_count
Maintain i_dio_count for all filesystems, not just those using DIO_LOCKING.
This these filesystems to also protect truncate against direct I/O requests
by using common code. Right now the only non-DIO_LOCKING filesystem that
appears to do so is XFS, which uses an opencoded variant of the i_dio_count
scheme.
Behaviour doesn't change for filesystems never calling inode_dio_wait.
For ext4 behaviour changes when using the dioread_nonlock option, which
previously was missing any protection between truncate and direct I/O reads.
For ocfs2 that handcrafted i_dio_count manipulations are replaced with
the common code now enable.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 736283c..22d6046 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2240,7 +2240,6 @@
relock:
/* to match setattr's i_mutex -> rw_lock ordering */
if (direct_io) {
- atomic_inc(&inode->i_dio_count);
have_alloc_sem = 1;
/* communicate with ocfs2_dio_end_io */
ocfs2_iocb_set_sem_locked(iocb);
@@ -2292,7 +2291,6 @@
*/
if (direct_io && !can_do_direct) {
ocfs2_rw_unlock(inode, rw_level);
- inode_dio_done(inode);
have_alloc_sem = 0;
rw_level = -1;
@@ -2379,10 +2377,8 @@
ocfs2_rw_unlock(inode, rw_level);
out_sems:
- if (have_alloc_sem) {
- inode_dio_done(inode);
+ if (have_alloc_sem)
ocfs2_iocb_clear_sem_locked(iocb);
- }
mutex_unlock(&inode->i_mutex);
@@ -2533,7 +2529,6 @@
*/
if (filp->f_flags & O_DIRECT) {
have_alloc_sem = 1;
- atomic_inc(&inode->i_dio_count);
ocfs2_iocb_set_sem_locked(iocb);
ret = ocfs2_rw_lock(inode, 0);
@@ -2575,10 +2570,9 @@
}
bail:
- if (have_alloc_sem) {
- inode_dio_done(inode);
+ if (have_alloc_sem)
ocfs2_iocb_clear_sem_locked(iocb);
- }
+
if (rw_level != -1)
ocfs2_rw_unlock(inode, rw_level);