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: 7b2404a886f8 ("cifs: Fix flushing, invalidation and file size with copy_file_range()")
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Steve French <stfrench@xxxxxxxxxxxxx>
cc: Paulo Alcantara <pc@xxxxxxxxxxxxx>
cc: Shyam Prasad N <nspmangalore@xxxxxxxxx>
cc: Rohith Surabattula <rohiths.msft@xxxxxxxxx>
cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
cc: Jeff Layton <jlayton@xxxxxxxxxx>
cc: linux-cifs@xxxxxxxxxxxxxxx
cc: linux-mm@xxxxxxxxx
cc: linux-fsdevel@xxxxxxxxxxxxxxx
---
fs/smb/client/cifsfs.c | 21 ++++-----------------
1 file changed, 4 insertions(+), 17 deletions(-)
diff --git a/fs/smb/client/cifsfs.c b/fs/smb/client/cifsfs.c
index d89485235425..2a2523c93944 100644
--- a/fs/smb/client/cifsfs.c
+++ b/fs/smb/client/cifsfs.c
@@ -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);
