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Commit 64b4e252 authored by Al Viro's avatar Al Viro
Browse files

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: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 9ce5a232

fs/ocfs2/file.c

+10 −4
Original line number Original line Diff line number Diff line
@@ -2439,10 +2439,14 @@ static ssize_t ocfs2_file_write_iter(struct kiocb *iocb, 
	/* buffered aio wouldn't have proper lock coverage today */

	/* buffered aio wouldn't have proper lock coverage today */

	BUG_ON(ret == -EIOCBQUEUED && !(file->f_flags & O_DIRECT));

	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) ||

	if (((file->f_flags & O_DSYNC) && !direct_io) || IS_SYNC(inode) ||

	    ((file->f_flags & O_DIRECT) && !direct_io)) {

	    ((file->f_flags & O_DIRECT) && !direct_io)) {

		ret = filemap_fdatawrite_range(file->f_mapping, *ppos,

		ret = filemap_fdatawrite_range(file->f_mapping,

					       *ppos + count - 1);

					       iocb->ki_pos - written,

					       iocb->ki_pos - 1);

		if (ret < 0)

		if (ret < 0)

			written = ret;

			written = ret;
@@ -2453,10 +2457,12 @@ static ssize_t ocfs2_file_write_iter(struct kiocb *iocb, 
		}

		}





		if (!ret)

		if (!ret)

			ret = filemap_fdatawait_range(file->f_mapping, *ppos,

			ret = filemap_fdatawait_range(file->f_mapping,

						      *ppos + count - 1);

						      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

	 * 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

	 * function pointer which is called when o_direct io completes so that