ocfs2: _really_ sync the right range
"ocfs2 syncs the wrong range" had been broken; prior to it the
code was doing the wrong thing in case of O_APPEND, all right,
but _after_ it we were syncing the wrong range in 100% cases.
*ppos, aka iocb->ki_pos is incremented prior to that point,
so we are always doing sync on the area _after_ the one we'd
written to.
Spotted by Joseph Qi <joseph.qi@huawei.com> back in January;
unfortunately, I'd missed his mail back then ;-/
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index a39067f..ba1790e 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2439,10 +2439,14 @@
/* buffered aio wouldn't have proper lock coverage today */
BUG_ON(ret == -EIOCBQUEUED && !(file->f_flags & O_DIRECT));
+ if (unlikely(written <= 0))
+ goto no_sync;
+
if (((file->f_flags & O_DSYNC) && !direct_io) || IS_SYNC(inode) ||
((file->f_flags & O_DIRECT) && !direct_io)) {
- ret = filemap_fdatawrite_range(file->f_mapping, *ppos,
- *ppos + count - 1);
+ ret = filemap_fdatawrite_range(file->f_mapping,
+ iocb->ki_pos - written,
+ iocb->ki_pos - 1);
if (ret < 0)
written = ret;
@@ -2453,10 +2457,12 @@
}
if (!ret)
- ret = filemap_fdatawait_range(file->f_mapping, *ppos,
- *ppos + count - 1);
+ ret = filemap_fdatawait_range(file->f_mapping,
+ iocb->ki_pos - written,
+ iocb->ki_pos - 1);
}
+no_sync:
/*
* deep in g_f_a_w_n()->ocfs2_direct_IO we pass in a ocfs2_dio_end_io
* function pointer which is called when o_direct io completes so that