CIFS: Simplify setlk error handling for mandatory locking

Now we allocate a lock structure at first, then we request to the server
and save the lock if server returned OK though void function - it prevents
the situation when we locked a file on the server and then return -ENOMEM
from setlk.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Acked-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index c1f063c..d9cc07f 100644 (file)
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -672,7 +672,7 @@ cifs_del_lock_waiters(struct cifsLockInfo *lock)
 }
 
 static bool
-cifs_find_lock_conflict(struct cifsInodeInfo *cinode, __u64 offset,
+__cifs_find_lock_conflict(struct cifsInodeInfo *cinode, __u64 offset,
                        __u64 length, __u8 type, __u16 netfid,
                        struct cifsLockInfo **conf_lock)
 {
@@ -694,6 +694,14 @@ cifs_find_lock_conflict(struct cifsInodeInfo *cinode, __u64 offset,
        return false;
 }
 
+static bool
+cifs_find_lock_conflict(struct cifsInodeInfo *cinode, struct cifsLockInfo *lock,
+                       struct cifsLockInfo **conf_lock)
+{
+       return __cifs_find_lock_conflict(cinode, lock->offset, lock->length,
+                                        lock->type, lock->netfid, conf_lock);
+}
+
 static int
 cifs_lock_test(struct cifsInodeInfo *cinode, __u64 offset, __u64 length,
               __u8 type, __u16 netfid, struct file_lock *flock)
@@ -704,8 +712,8 @@ cifs_lock_test(struct cifsInodeInfo *cinode, __u64 offset, __u64 length,
 
        mutex_lock(&cinode->lock_mutex);
 
-       exist = cifs_find_lock_conflict(cinode, offset, length, type, netfid,
-                                       &conf_lock);
+       exist = __cifs_find_lock_conflict(cinode, offset, length, type, netfid,
+                                         &conf_lock);
        if (exist) {
                flock->fl_start = conf_lock->offset;
                flock->fl_end = conf_lock->offset + conf_lock->length - 1;
@@ -723,40 +731,27 @@ cifs_lock_test(struct cifsInodeInfo *cinode, __u64 offset, __u64 length,
        return rc;
 }
 
-static int
-cifs_lock_add(struct cifsInodeInfo *cinode, __u64 len, __u64 offset,
-             __u8 type, __u16 netfid)
+static void
+cifs_lock_add(struct cifsInodeInfo *cinode, struct cifsLockInfo *lock)
 {
-       struct cifsLockInfo *li;
-
-       li = cifs_lock_init(len, offset, type, netfid);
-       if (!li)
-               return -ENOMEM;
-
        mutex_lock(&cinode->lock_mutex);
-       list_add_tail(&li->llist, &cinode->llist);
+       list_add_tail(&lock->llist, &cinode->llist);
        mutex_unlock(&cinode->lock_mutex);
-       return 0;
 }
 
 static int
-cifs_lock_add_if(struct cifsInodeInfo *cinode, __u64 offset, __u64 length,
-                __u8 type, __u16 netfid, bool wait)
+cifs_lock_add_if(struct cifsInodeInfo *cinode, struct cifsLockInfo *lock,
+                bool wait)
 {
-       struct cifsLockInfo *lock, *conf_lock;
+       struct cifsLockInfo *conf_lock;
        bool exist;
        int rc = 0;
 
-       lock = cifs_lock_init(length, offset, type, netfid);
-       if (!lock)
-               return -ENOMEM;
-
 try_again:
        exist = false;
        mutex_lock(&cinode->lock_mutex);
 
-       exist = cifs_find_lock_conflict(cinode, offset, length, type, netfid,
-                                       &conf_lock);
+       exist = cifs_find_lock_conflict(cinode, lock, &conf_lock);
        if (!exist && cinode->can_cache_brlcks) {
                list_add_tail(&lock->llist, &cinode->llist);
                mutex_unlock(&cinode->lock_mutex);
@@ -781,7 +776,6 @@ try_again:
                }
        }
 
-       kfree(lock);
        mutex_unlock(&cinode->lock_mutex);
        return rc;
 }
@@ -1254,20 +1248,26 @@ cifs_setlk(struct file *file,  struct file_lock *flock, __u8 type,
        }
 
        if (lock) {
-               rc = cifs_lock_add_if(cinode, flock->fl_start, length,
-                                     type, netfid, wait_flag);
+               struct cifsLockInfo *lock;
+
+               lock = cifs_lock_init(length, flock->fl_start, type, netfid);
+               if (!lock)
+                       return -ENOMEM;
+
+               rc = cifs_lock_add_if(cinode, lock, wait_flag);
                if (rc < 0)
-                       return rc;
-               else if (!rc)
+                       kfree(lock);
+               if (rc <= 0)
                        goto out;
 
                rc = CIFSSMBLock(xid, tcon, netfid, current->tgid, length,
                                 flock->fl_start, 0, 1, type, wait_flag, 0);
-               if (rc == 0) {
-                       /* For Windows locks we must store them. */
-                       rc = cifs_lock_add(cinode, length, flock->fl_start,
-                                          type, netfid);
+               if (rc) {
+                       kfree(lock);
+                       goto out;
                }
+
+               cifs_lock_add(cinode, lock);
        } else if (unlock)
                rc = cifs_unlock_range(cfile, flock, xid);