smb3: Add new parm "nodelete"
In order to handle workloads where it is important to make sure that
a buggy app did not delete content on the drive, the new mount option
"nodelete" allows standard permission checks on the server to work,
but prevents on the client any attempts to unlink a file or delete
a directory on that mount point. This can be helpful when running
a little understood app on a network mount that contains important
content that should not be deleted.
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 329babc..57d1cc6 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -75,7 +75,7 @@ enum {
Opt_forceuid, Opt_noforceuid,
Opt_forcegid, Opt_noforcegid,
Opt_noblocksend, Opt_noautotune, Opt_nolease,
- Opt_hard, Opt_soft, Opt_perm, Opt_noperm,
+ Opt_hard, Opt_soft, Opt_perm, Opt_noperm, Opt_nodelete,
Opt_mapposix, Opt_nomapposix,
Opt_mapchars, Opt_nomapchars, Opt_sfu,
Opt_nosfu, Opt_nodfs, Opt_posixpaths,
@@ -141,6 +141,7 @@ static const match_table_t cifs_mount_option_tokens = {
{ Opt_soft, "soft" },
{ Opt_perm, "perm" },
{ Opt_noperm, "noperm" },
+ { Opt_nodelete, "nodelete" },
{ Opt_mapchars, "mapchars" }, /* SFU style */
{ Opt_nomapchars, "nomapchars" },
{ Opt_mapposix, "mapposix" }, /* SFM style */
@@ -1760,6 +1761,9 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
case Opt_noperm:
vol->noperm = 1;
break;
+ case Opt_nodelete:
+ vol->nodelete = 1;
+ break;
case Opt_mapchars:
vol->sfu_remap = true;
vol->remap = false; /* disable SFM mapping */
@@ -3362,6 +3366,8 @@ static int match_tcon(struct cifs_tcon *tcon, struct smb_vol *volume_info)
return 0;
if (tcon->no_lease != volume_info->no_lease)
return 0;
+ if (tcon->nodelete != volume_info->nodelete)
+ return 0;
return 1;
}
@@ -3597,6 +3603,7 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb_vol *volume_info)
tcon->retry = volume_info->retry;
tcon->nocase = volume_info->nocase;
tcon->nohandlecache = volume_info->nohandlecache;
+ tcon->nodelete = volume_info->nodelete;
tcon->local_lease = volume_info->local_lease;
INIT_LIST_HEAD(&tcon->pending_opens);