cifs: stuff the fl_owner into "pid" field in the lock request

Right now, we send the tgid cross the wire. What we really want to send
though is a hashed fl_owner_t since samba treats this field as a generic
lockowner.

It turns out that because we enforce and release locks locally before
they are ever sent to the server, this patch makes no difference in
behavior. Still, setting OFD locks on the server using the process
pid seems wrong, so I think this patch still makes sense.

Signed-off-by: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Pavel Shilovsky <pshilovsky@samba.org>
Acked-by: Sachin Prabhu <sprabhu@redhat.com>

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 5d8b7edf8a8f69009114e56e28c530fb4e7e686f..5d841f39c4b70e853e5b74d1cb6e01e7d112fd25 100644 (file)
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -87,6 +87,7 @@ extern mempool_t *cifs_req_poolp;
 extern mempool_t *cifs_mid_poolp;
 
 struct workqueue_struct        *cifsiod_wq;
+__u32 cifs_lock_secret;
 
 /*
  * Bumps refcount for cifs super block.
@@ -1266,6 +1267,8 @@ init_cifs(void)
        spin_lock_init(&cifs_file_list_lock);
        spin_lock_init(&GlobalMid_Lock);
 
+       get_random_bytes(&cifs_lock_secret, sizeof(cifs_lock_secret));
+
        if (cifs_max_pending < 2) {
                cifs_max_pending = 2;
                cifs_dbg(FYI, "cifs_max_pending set to min of 2\n");

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index bba106cdc43c4c5703568ac82016714983e1d7bc..8f1d8c1e72bece412a926d0e20b9bdc95a7fa9ee 100644 (file)
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1619,6 +1619,7 @@ void cifs_oplock_break(struct work_struct *work);
 
 extern const struct slow_work_ops cifs_oplock_break_ops;
 extern struct workqueue_struct *cifsiod_wq;
+extern __u32 cifs_lock_secret;
 
 extern mempool_t *cifs_mid_poolp;
 

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 9793ae0bcaa2bc678f9a688c167ef2b091cc858f..d4890b6dc22db0a4c7345b195e0209c5d32cf0b0 100644 (file)
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1112,6 +1112,12 @@ cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
        return rc;
 }
 
+static __u32
+hash_lockowner(fl_owner_t owner)
+{
+       return cifs_lock_secret ^ hash32_ptr((const void *)owner);
+}
+
 struct lock_to_push {
        struct list_head llist;
        __u64 offset;
@@ -1178,7 +1184,7 @@ cifs_push_posix_locks(struct cifsFileInfo *cfile)
                else
                        type = CIFS_WRLCK;
                lck = list_entry(el, struct lock_to_push, llist);
-               lck->pid = flock->fl_pid;
+               lck->pid = hash_lockowner(flock->fl_owner);
                lck->netfid = cfile->fid.netfid;
                lck->length = length;
                lck->type = type;
@@ -1305,7 +1311,8 @@ cifs_getlk(struct file *file, struct file_lock *flock, __u32 type,
                        posix_lock_type = CIFS_RDLCK;
                else
                        posix_lock_type = CIFS_WRLCK;
-               rc = CIFSSMBPosixLock(xid, tcon, netfid, current->tgid,
+               rc = CIFSSMBPosixLock(xid, tcon, netfid,
+                                     hash_lockowner(flock->fl_owner),
                                      flock->fl_start, length, flock,
                                      posix_lock_type, wait_flag);
                return rc;
@@ -1505,7 +1512,8 @@ cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
                        posix_lock_type = CIFS_UNLCK;
 
                rc = CIFSSMBPosixLock(xid, tcon, cfile->fid.netfid,
-                                     current->tgid, flock->fl_start, length,
+                                     hash_lockowner(flock->fl_owner),
+                                     flock->fl_start, length,
                                      NULL, posix_lock_type, wait_flag);
                goto out;
        }