@@ -3560,8 +3560,11 @@ static long smb3_zero_range(struct file *file, struct cifs_tcon *tcon,
/*
* We zero the range through ioctl, so we need remove the page caches
* first, otherwise the data may be inconsistent with the server.
+ *
+ * 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.
*/
- truncate_pagecache_range(inode, offset, offset + len - 1);
+ truncate_pagecache_range(inode, min(offset, i_size), offset + len - 1);
netfs_wait_for_outstanding_io(inode);
/* if file not oplocked can't be sure whether asking to extend size */
smb3_zero_range() removed the pagecache only for the range being zeroed, so when it 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. Lower the discard boundary to the smaller of the zero-range offset and the old EOF. Fixes: 72c419d9b073 ("cifs: fix smb3_zero_range so it can expand the file-size when required") 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/smb2ops.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)