cifs: Fix missing set of remote_i_size

Occasionally, the generic/001 xfstest will fail indicating corruption in
one of the copy chains when run on cifs against a server that supports
FSCTL_DUPLICATE_EXTENTS_TO_FILE (eg. Samba with a share on btrfs).  The
problem is that the remote_i_size value isn't updated by cifs_setsize()
when called by smb2_duplicate_extents(), but i_size *is*.

This may cause cifs_remap_file_range() to then skip the bit after calling
->duplicate_extents() that sets sizes.

Fix this by calling netfs_resize_file() in smb2_duplicate_extents() before
calling cifs_setsize() to set i_size.

This means we don't then need to call netfs_resize_file() upon return from
->duplicate_extents(), but we also fix the test to compare against the pre-dup
inode size.

[Note that this goes back before the addition of remote_i_size with the
netfs_inode struct.  It should probably have been setting cifsi->server_eof
previously.]

Fixes: cfc63fc8126a ("smb3: fix cached file size problems in duplicate extents (reflink)")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Paulo Alcantara <pc@manguebit.com>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: Rohith Surabattula <rohiths.msft@gmail.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/smb/client/cifsfs.c b/fs/smb/client/cifsfs.c
index ec5b639..a665aac 100644 (file)
--- a/fs/smb/client/cifsfs.c
+++ b/fs/smb/client/cifsfs.c
@@ -1226,7 +1226,7 @@ static loff_t cifs_remap_file_range(struct file *src_file, loff_t off,
        struct cifsFileInfo *smb_file_src = src_file->private_data;
        struct cifsFileInfo *smb_file_target = dst_file->private_data;
        struct cifs_tcon *target_tcon, *src_tcon;
-       unsigned long long destend, fstart, fend, new_size;
+       unsigned long long destend, fstart, fend, old_size, new_size;
        unsigned int xid;
        int rc;
 
@@ -1293,6 +1293,7 @@ static loff_t cifs_remap_file_range(struct file *src_file, loff_t off,
                goto unlock;
        if (fend > target_cifsi->netfs.zero_point)
                target_cifsi->netfs.zero_point = fend + 1;
+       old_size = target_cifsi->netfs.remote_i_size;
 
        /* Discard all the folios that overlap the destination region. */
        cifs_dbg(FYI, "about to discard pages %llx-%llx\n", fstart, fend);
@@ -1305,9 +1306,8 @@ static loff_t cifs_remap_file_range(struct file *src_file, loff_t off,
        if (target_tcon->ses->server->ops->duplicate_extents) {
                rc = target_tcon->ses->server->ops->duplicate_extents(xid,
                        smb_file_src, smb_file_target, off, len, destoff);
-               if (rc == 0 && new_size > i_size_read(target_inode)) {
+               if (rc == 0 && new_size > old_size) {
                        truncate_setsize(target_inode, new_size);
-                       netfs_resize_file(&target_cifsi->netfs, new_size, true);
                        fscache_resize_cookie(cifs_inode_cookie(target_inode),
                                              new_size);
                }

diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index b87b70e..4ce6c31 100644 (file)
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -2028,6 +2028,7 @@ smb2_duplicate_extents(const unsigned int xid,
                 * size will be queried on next revalidate, but it is important
                 * to make sure that file's cached size is updated immediately
                 */
+               netfs_resize_file(netfs_inode(inode), dest_off + len, true);
                cifs_setsize(inode, dest_off + len);
        }
        rc = SMB2_ioctl(xid, tcon, trgtfile->fid.persistent_fid,