futex: update documentation for ordering guarantees

[linux.git] / fs / locks.c

diff --git a/fs/locks.c b/fs/locks.c
index 09d6c8c33c815d168b5bbaf5a36619a21ccf322e..13fc7a6d380ae6648945c8956cc53901de2d0ccc 100644 (file)
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1155,13 +1155,14 @@ EXPORT_SYMBOL(posix_lock_file_wait);
 
 /**
  * locks_mandatory_locked - Check for an active lock
- * @inode: the file to check
+ * @file: the file to check
  *
  * Searches the inode's list of locks to find any POSIX locks which conflict.
  * This function is called from locks_verify_locked() only.
  */
-int locks_mandatory_locked(struct inode *inode)
+int locks_mandatory_locked(struct file *file)
 {
+       struct inode *inode = file_inode(file);
        fl_owner_t owner = current->files;
        struct file_lock *fl;
 
@@ -1172,7 +1173,7 @@ int locks_mandatory_locked(struct inode *inode)
        for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
                if (!IS_POSIX(fl))
                        continue;
-               if (fl->fl_owner != owner)
+               if (fl->fl_owner != owner && fl->fl_owner != (fl_owner_t)file)
                        break;
        }
        spin_unlock(&inode->i_lock);
@@ -1198,19 +1199,30 @@ int locks_mandatory_area(int read_write, struct inode *inode,
 {
        struct file_lock fl;
        int error;
+       bool sleep = false;
 
        locks_init_lock(&fl);
-       fl.fl_owner = current->files;
        fl.fl_pid = current->tgid;
        fl.fl_file = filp;
        fl.fl_flags = FL_POSIX | FL_ACCESS;
        if (filp && !(filp->f_flags & O_NONBLOCK))
-               fl.fl_flags |= FL_SLEEP;
+               sleep = true;
        fl.fl_type = (read_write == FLOCK_VERIFY_WRITE) ? F_WRLCK : F_RDLCK;
        fl.fl_start = offset;
        fl.fl_end = offset + count - 1;
 
        for (;;) {
+               if (filp) {
+                       fl.fl_owner = (fl_owner_t)filp;
+                       fl.fl_flags &= ~FL_SLEEP;
+                       error = __posix_lock_file(inode, &fl, NULL);
+                       if (!error)
+                               break;
+               }
+
+               if (sleep)
+                       fl.fl_flags |= FL_SLEEP;
+               fl.fl_owner = current->files;
                error = __posix_lock_file(inode, &fl, NULL);
                if (error != FILE_LOCK_DEFERRED)
                        break;