collapse range doesn't discard the affected cached region
so can risk temporarily corrupting the file data. This
fixes xfstest generic/031
I also decided to merge a minor cleanup to this into the same patch
(avoiding rereading inode size repeatedly unnecessarily) to make it
clearer.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 5476b5dd82c8b ("cifs: add support for FALLOC_FL_COLLAPSE_RANGE")
Reported-by: David Howells <dhowells@xxxxxxxxxx>
Tested-by: David Howells <dhowells@xxxxxxxxxx>
Reviewed-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
See attached:
--
Thanks,
Steve
From bce7aeed5e9263097209cf7cfb0c7ce1a2afcce1 Mon Sep 17 00:00:00 2001
From: Steve French <stfrench@xxxxxxxxxxxxx>
Date: Fri, 19 Aug 2022 18:57:05 -0500
Subject: [PATCH] smb3: fix collapse range temporary data corruption
collapse range doesn't discard the affected cached region
so can risk temporarily corrupting the file data. This
fixes xfstest generic/031
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 5476b5dd82c8b ("cifs: add support for FALLOC_FL_COLLAPSE_RANGE")
Reported-by: David Howells <dhowells@xxxxxxxxxx>
Tested-by: David Howells <dhowells@xxxxxxxxxx>
Reviewed-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
fs/cifs/smb2ops.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 96f3b0573606..cd9fa984538a 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -3677,24 +3677,25 @@ static long smb3_collapse_range(struct file *file, struct cifs_tcon *tcon,
struct cifsFileInfo *cfile = file->private_data;
struct cifsInodeInfo *cifsi;
__le64 eof;
+ loff_t old_eof;
xid = get_xid();
inode = d_inode(cfile->dentry);
cifsi = CIFS_I(inode);
-
- if (off >= i_size_read(inode) ||
- off + len >= i_size_read(inode)) {
+ old_eof = i_size_read(inode);
+ if ((off >= old_eof) ||
+ off + len >= old_eof) {
rc = -EINVAL;
goto out;
}
rc = smb2_copychunk_range(xid, cfile, cfile, off + len,
- i_size_read(inode) - off - len, off);
+ old_eof - off - len, off);
if (rc < 0)
goto out;
- eof = cpu_to_le64(i_size_read(inode) - len);
+ eof = cpu_to_le64(old_eof - len);
rc = SMB2_set_eof(xid, tcon, cfile->fid.persistent_fid,
cfile->fid.volatile_fid, cfile->pid, &eof);
if (rc < 0)
@@ -3702,6 +3703,7 @@ static long smb3_collapse_range(struct file *file, struct cifs_tcon *tcon,
rc = 0;
+ truncate_pagecache_range(inode, off, old_eof);
cifsi->server_eof = i_size_read(inode) - len;
truncate_setsize(inode, cifsi->server_eof);
fscache_resize_cookie(cifs_inode_cookie(inode), cifsi->server_eof);
--
2.34.1
