Commit 8101d6e1 authored by David Howells's avatar David Howells Committed by Steve French
Browse files

cifs: Fix copy offload to flush destination region 



Fix cifs_file_copychunk_range() to flush the destination region before
invalidating it to avoid potential loss of data should the copy fail, in
whole or in part, in some way.

Fixes: 7b2404a8 ("cifs: Fix flushing, invalidation and file size with copy_file_range()")
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
cc: Steve French <stfrench@microsoft.com>
cc: Paulo Alcantara <pc@manguebit.com>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: Rohith Surabattula <rohiths.msft@gmail.com>
cc: Matthew Wilcox <willy@infradead.org>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: linux-mm@kvack.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 1da29f2c

fs/smb/client/cifsfs.c

+4 −17
Original line number Diff line number Diff line
@@ -1341,7 +1341,6 @@ ssize_t cifs_file_copychunk_range(unsigned int xid, 
	struct cifsFileInfo *smb_file_target;

	struct cifs_tcon *src_tcon;

	struct cifs_tcon *target_tcon;

	unsigned long long destend, fstart, fend;

	ssize_t rc;



	cifs_dbg(FYI, "copychunk range\n");
@@ -1391,25 +1390,13 @@ ssize_t cifs_file_copychunk_range(unsigned int xid, 
			goto unlock;

	}



	destend = destoff + len - 1;



	/* Flush the folios at either end of the destination range to prevent

	 * accidental loss of dirty data outside of the range.

	/* Flush and invalidate all the folios in the destination region.  If

	 * the copy was successful, then some of the flush is extra overhead,

	 * but we need to allow for the copy failing in some way (eg. ENOSPC).

	 */

	fstart = destoff;

	fend = destend;



	rc = cifs_flush_folio(target_inode, destoff, &fstart, &fend, true);

	rc = filemap_invalidate_inode(target_inode, true, destoff, destoff + len - 1);

	if (rc)

		goto unlock;

	rc = cifs_flush_folio(target_inode, destend, &fstart, &fend, false);

	if (rc)

		goto unlock;

	if (fend > target_cifsi->netfs.zero_point)

		target_cifsi->netfs.zero_point = fend + 1;



	/* Discard all the folios that overlap the destination region. */

	truncate_inode_pages_range(&target_inode->i_data, fstart, fend);



	fscache_invalidate(cifs_inode_cookie(target_inode), NULL,

			   i_size_read(target_inode), 0);