CIFS: Add rwpidforward mount option
Add rwpidforward mount option that switches on a mode when we forward
pid of a process who opened a file to any read and write operation.
This can prevent applications like WINE from failing on read or write
operation on a previously locked file region from the same netfd from
another process if we use mandatory brlock style.
It is actual for WINE because during a run of WINE program two processes
work on the same netfd - share the same file struct between several VFS
fds:
1) WINE-server does open and lock;
2) WINE-application does read and write.
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 261ca81d..21bc835 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1359,6 +1359,8 @@
vol->server_ino = 1;
} else if (strnicmp(data, "noserverino", 9) == 0) {
vol->server_ino = 0;
+ } else if (strnicmp(data, "rwpidforward", 4) == 0) {
+ vol->rwpidforward = 1;
} else if (strnicmp(data, "cifsacl", 7) == 0) {
vol->cifs_acl = 1;
} else if (strnicmp(data, "nocifsacl", 9) == 0) {
@@ -2708,6 +2710,8 @@
cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_NOSSYNC;
if (pvolume_info->mand_lock)
cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_NOPOSIXBRL;
+ if (pvolume_info->rwpidforward)
+ cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RWPIDFORWARD;
if (pvolume_info->cifs_acl)
cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_CIFS_ACL;
if (pvolume_info->override_uid)
