Thread (30 messages) 30 messages, 2 authors, 2022-08-31

Re: [PATCH 08/14] ocfs2: replace ll_rw_block()

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From: Jan Kara <jack@suse.cz>
Date: 2022-08-31 11:31:39
Also in: linux-fsdevel, lkml, ntfs3, ocfs2-devel

On Wed 31-08-22 15:21:05, Zhang Yi wrote:
quoted hunk ↗ jump to hunk
ll_rw_block() is not safe for the sync read path because it cannot
guarantee that submitting read IO if the buffer has been locked. We
could get false positive EIO after wait_on_buffer() if the buffer has
been locked by others. So stop using ll_rw_block() in ocfs2.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
---
 fs/ocfs2/aops.c  | 2 +-
 fs/ocfs2/super.c | 5 +----
 2 files changed, 2 insertions(+), 5 deletions(-)
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index af4157f61927..1d65f6ef00ca 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -636,7 +636,7 @@ int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno,
 			   !buffer_new(bh) &&
 			   ocfs2_should_read_blk(inode, page, block_start) &&
 			   (block_start < from || block_end > to)) {
-			ll_rw_block(REQ_OP_READ, 1, &bh);
+			bh_read_nowait(bh, 0);
 			*wait_bh++=bh;
 		}
 
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index e2cc9eec287c..4050f35bbd0c 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -1763,10 +1763,7 @@ static int ocfs2_get_sector(struct super_block *sb,
 	lock_buffer(*bh);
 	if (!buffer_dirty(*bh))
 		clear_buffer_uptodate(*bh);
-	unlock_buffer(*bh);
-	ll_rw_block(REQ_OP_READ, 1, bh);
-	wait_on_buffer(*bh);
-	if (!buffer_uptodate(*bh)) {
+	if (bh_read_locked(*bh, 0)) {
 		mlog_errno(-EIO);
 		brelse(*bh);
 		*bh = NULL;
I would just use bh_read() here and drop bh_read_locked() altogether...

								Honza
-- 
Jan Kara [off-list ref]
SUSE Labs, CR
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