[PATCH 6.9 279/374] cifs: Fix missing set of remote_i_size

Greg Kroah-Hartman
2024-06-06T14:10:42Z

From: David Howells <dhowells@redhat.com>

[ Upstream commit 93a43155127fec0f8cc942d63b76668c2f8f69fa ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/smb/client/cifsfs.c | 6 +++---
fs/smb/client/smb2ops.c | 1 +
2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/fs/smb/client/cifsfs.c b/fs/smb/client/cifsfs.c
index c8449f43856c5..4fb21affe4e11 100644
--- a/fs/smb/client/cifsfs.c
+++ b/fs/smb/client/cifsfs.c
@@ -1277,7 +1277,7 @@ 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;

@@ -1344,6 +1344,7 @@ 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);
@@ -1356,9 +1357,8 @@ 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 28f0b7d19d534..6fea0aed43461 100644
--- 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,
--
2.43.0