@@ -1581,8 +1581,13 @@ ssize_t cifs_file_copychunk_range(unsigned int xid,
/* 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).
+ *
+ * Start at the old EOF when extending so the folio straddling it, which
+ * may hold data written past EOF through an mmap, is dropped too.
*/
- rc = filemap_invalidate_inode(target_inode, true, destoff, destoff + len - 1);
+ rc = filemap_invalidate_inode(target_inode, true,
+ min(destoff, i_size_read(target_inode)),
+ destoff + len - 1);
if (rc)
goto unlock;
cifs_file_copychunk_range() invalidated the pagecache only for the destination region, so when a copy extends the file the folio straddling the old EOF - which may hold data dirtied past EOF through an mmap - was never dropped and became visible as file content once the file was extended. Start the invalidation at the smaller of the destination offset and the old EOF. filemap_invalidate_inode() writes back before invalidating while i_size is still old, so nothing past the old EOF is flushed to the server. Fixes: 8101d6e112e2 ("cifs: Fix copy offload to flush destination region") Reviewed-by: David Howells <dhowells@redhat.com> Reviewed-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Paulo Alcantara <pc@manguebit.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Namjae Jeon <linkinjeon@kernel.org> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: Shyam Prasad N <sprasad@microsoft.com> Cc: Tom Talpey <tom@talpey.com> Cc: Bharath SM <bharathsm@microsoft.com> Cc: stable@vger.kernel.org --- fs/smb/client/cifsfs.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)