Merge branch 'master' of /home/trondmy/kernel/linux-2.6/

[pandora-kernel.git] / fs / locks.c

diff --git a/fs/locks.c b/fs/locks.c
index 69435c6..1ad29c9 100644 (file)
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -703,7 +703,7 @@ EXPORT_SYMBOL(posix_test_lock);
  * from a broken NFS client. But broken NFS clients have a lot more to
  * worry about than proper deadlock detection anyway... --okir
  */
-int posix_locks_deadlock(struct file_lock *caller_fl,
+static int posix_locks_deadlock(struct file_lock *caller_fl,
                                struct file_lock *block_fl)
 {
        struct list_head *tmp;
@@ -722,8 +722,6 @@ next_task:
        return 0;
 }
 
-EXPORT_SYMBOL(posix_locks_deadlock);
-
 /* Try to create a FLOCK lock on filp. We always insert new FLOCK locks
  * at the head of the list, but that's secret knowledge known only to
  * flock_lock_file and posix_lock_file.
@@ -794,7 +792,8 @@ out:
 static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request, struct file_lock *conflock)
 {
        struct file_lock *fl;
-       struct file_lock *new_fl, *new_fl2;
+       struct file_lock *new_fl = NULL;
+       struct file_lock *new_fl2 = NULL;
        struct file_lock *left = NULL;
        struct file_lock *right = NULL;
        struct file_lock **before;
@@ -803,9 +802,15 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request
        /*
         * We may need two file_lock structures for this operation,
         * so we get them in advance to avoid races.
+        *
+        * In some cases we can be sure, that no new locks will be needed
         */
-       new_fl = locks_alloc_lock();
-       new_fl2 = locks_alloc_lock();
+       if (!(request->fl_flags & FL_ACCESS) &&
+           (request->fl_type != F_UNLCK ||
+            request->fl_start != 0 || request->fl_end != OFFSET_MAX)) {
+               new_fl = locks_alloc_lock();
+               new_fl2 = locks_alloc_lock();
+       }
 
        lock_kernel();
        if (request->fl_type != F_UNLCK) {
@@ -834,14 +839,7 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request
        if (request->fl_flags & FL_ACCESS)
                goto out;
 
-       error = -ENOLCK; /* "no luck" */
-       if (!(new_fl && new_fl2))
-               goto out;
-
        /*
-        * We've allocated the new locks in advance, so there are no
-        * errors possible (and no blocking operations) from here on.
-        * 
         * Find the first old lock with the same owner as the new lock.
         */
        
@@ -938,10 +936,25 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request
                before = &fl->fl_next;
        }
 
+       /*
+        * The above code only modifies existing locks in case of
+        * merging or replacing.  If new lock(s) need to be inserted
+        * all modifications are done bellow this, so it's safe yet to
+        * bail out.
+        */
+       error = -ENOLCK; /* "no luck" */
+       if (right && left == right && !new_fl2)
+               goto out;
+
        error = 0;
        if (!added) {
                if (request->fl_type == F_UNLCK)
                        goto out;
+
+               if (!new_fl) {
+                       error = -ENOLCK;
+                       goto out;
+               }
                locks_copy_lock(new_fl, request);
                locks_insert_lock(before, new_fl);
                new_fl = NULL;
@@ -1881,19 +1894,18 @@ out:
  */
 void locks_remove_posix(struct file *filp, fl_owner_t owner)
 {
-       struct file_lock lock, **before;
+       struct file_lock lock;
 
        /*
         * If there are no locks held on this file, we don't need to call
         * posix_lock_file().  Another process could be setting a lock on this
         * file at the same time, but we wouldn't remove that lock anyway.
         */
-       before = &filp->f_dentry->d_inode->i_flock;
-       if (*before == NULL)
+       if (!filp->f_dentry->d_inode->i_flock)
                return;
 
        lock.fl_type = F_UNLCK;
-       lock.fl_flags = FL_POSIX;
+       lock.fl_flags = FL_POSIX | FL_CLOSE;
        lock.fl_start = 0;
        lock.fl_end = OFFSET_MAX;
        lock.fl_owner = owner;
@@ -1902,25 +1914,11 @@ void locks_remove_posix(struct file *filp, fl_owner_t owner)
        lock.fl_ops = NULL;
        lock.fl_lmops = NULL;
 
-       if (filp->f_op && filp->f_op->lock != NULL) {
+       if (filp->f_op && filp->f_op->lock != NULL)
                filp->f_op->lock(filp, F_SETLK, &lock);
-               goto out;
-       }
+       else
+               posix_lock_file(filp, &lock);
 
-       /* Can't use posix_lock_file here; we need to remove it no matter
-        * which pid we have.
-        */
-       lock_kernel();
-       while (*before != NULL) {
-               struct file_lock *fl = *before;
-               if (IS_POSIX(fl) && posix_same_owner(fl, &lock)) {
-                       locks_delete_lock(before);
-                       continue;
-               }
-               before = &fl->fl_next;
-       }
-       unlock_kernel();
-out:
        if (lock.fl_ops && lock.fl_ops->fl_release_private)
                lock.fl_ops->fl_release_private(&lock);
 }