Ocfs2: Teach 'coherency=full' O_DIRECT writes to correctly up_read i_alloc_sem.
Due to newly-introduced 'coherency=full' O_DIRECT writes also takes the EX
rw_lock like buffered writes did(rw_level == 1), it turns out messing the
usage of 'level' in ocfs2_dio_end_io() up, which caused i_alloc_sem being
failed to get up_read'd correctly.
This patch tries to teach ocfs2_dio_end_io to understand well on all locking
stuffs by explicitly introducing a new bit for i_alloc_sem in iocb's private
data, just like what we did for rw_lock.
Signed-off-by: Tristan Ye <tristan.ye@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 77b4c04..f6cba56 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2241,11 +2241,15 @@
mutex_lock(&inode->i_mutex);
+ ocfs2_iocb_clear_sem_locked(iocb);
+
relock:
/* to match setattr's i_mutex -> i_alloc_sem -> rw_lock ordering */
if (direct_io) {
down_read(&inode->i_alloc_sem);
have_alloc_sem = 1;
+ /* communicate with ocfs2_dio_end_io */
+ ocfs2_iocb_set_sem_locked(iocb);
}
/*
@@ -2382,8 +2386,10 @@
ocfs2_rw_unlock(inode, rw_level);
out_sems:
- if (have_alloc_sem)
+ if (have_alloc_sem) {
up_read(&inode->i_alloc_sem);
+ ocfs2_iocb_clear_sem_locked(iocb);
+ }
mutex_unlock(&inode->i_mutex);
@@ -2527,6 +2533,8 @@
goto bail;
}
+ ocfs2_iocb_clear_sem_locked(iocb);
+
/*
* buffered reads protect themselves in ->readpage(). O_DIRECT reads
* need locks to protect pending reads from racing with truncate.
@@ -2534,6 +2542,7 @@
if (filp->f_flags & O_DIRECT) {
down_read(&inode->i_alloc_sem);
have_alloc_sem = 1;
+ ocfs2_iocb_set_sem_locked(iocb);
ret = ocfs2_rw_lock(inode, 0);
if (ret < 0) {
@@ -2575,8 +2584,10 @@
}
bail:
- if (have_alloc_sem)
+ if (have_alloc_sem) {
up_read(&inode->i_alloc_sem);
+ ocfs2_iocb_clear_sem_locked(iocb);
+ }
if (rw_level != -1)
ocfs2_rw_unlock(inode, rw_level);
mlog_exit(ret);