Commit 856473cd authored Jul 06, 2020 by Andreas Gruenbacher Committed by Darrick J. Wong Jul 06, 2020

iomap: Make sure iomap_end is called after iomap_begin



Make sure iomap_end is always called when iomap_begin succeeds.

Without this fix, iomap_end won't be called when a filesystem's
iomap_begin operation returns an invalid mapping, bypassing any
unlocking done in iomap_end.  With this fix, the unlocking will still
happen.

This bug was found by Bob Peterson during code review.  It's unlikely
that such iomap_begin bugs will survive to affect users, so backporting
this fix seems unnecessary.

Fixes: ae259a9c ("fs: introduce iomap infrastructure")
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

parent dcb7fd82

fs/iomap/apply.c

+9 −4

Original line number	Diff line number	Diff line
		@@ -46,10 +46,14 @@ iomap_apply(struct inode *inode, loff_t pos, loff_t length, unsigned flags,
		ret = ops->iomap_begin(inode, pos, length, flags, &iomap, &srcmap);
		if (ret)
		return ret;
		if (WARN_ON(iomap.offset > pos))
		return -EIO;
		if (WARN_ON(iomap.length == 0))
		return -EIO;
		if (WARN_ON(iomap.offset > pos)) {
		written = -EIO;
		goto out;
		}
		if (WARN_ON(iomap.length == 0)) {
		written = -EIO;
		goto out;
		}

		trace_iomap_apply_dstmap(inode, &iomap);
		if (srcmap.type != IOMAP_HOLE)
		@@ -80,6 +84,7 @@ iomap_apply(struct inode *inode, loff_t pos, loff_t length, unsigned flags,
		written = actor(inode, pos, length, data, &iomap,
		srcmap.type != IOMAP_HOLE ? &srcmap : &iomap);

		out:
		/*
		* Now the data has been copied, commit the range we've copied. This
		* should not fail unless the filesystem has had a fatal error.

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