1 files changed, 156 insertions, 108 deletions

diff --git a/fs/locks.c b/fs/locks.c
index 325578074742..671a034dc999 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -665,11 +665,11 @@ static int locks_block_on_timeout(struct file_lock *blocker, struct file_lock *w
 }
 
 int
-posix_test_lock(struct file *filp, struct file_lock *fl,
-                struct file_lock *conflock)
+posix_test_lock(struct file *filp, struct file_lock *fl)
 {
         struct file_lock *cfl;
 
+        fl->fl_type = F_UNLCK;
         lock_kernel();
         for (cfl = filp->f_path.dentry->d_inode->i_flock; cfl; cfl = cfl->fl_next) {
                 if (!IS_POSIX(cfl))
@@ -678,7 +678,7 @@ posix_test_lock(struct file *filp, struct file_lock *fl,
                         break;
         }
         if (cfl) {
-                __locks_copy_lock(conflock, cfl);
+                __locks_copy_lock(fl, cfl);
                 unlock_kernel();
                 return 1;
         }
@@ -800,7 +800,7 @@ out:
         return error;
 }
 
-static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request, struct file_lock *conflock)
+static int __posix_lock_file(struct inode *inode, struct file_lock *request, struct file_lock *conflock)
 {
         struct file_lock *fl;
         struct file_lock *new_fl = NULL;
@@ -1006,6 +1006,7 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request
  * posix_lock_file - Apply a POSIX-style lock to a file
  * @filp: The file to apply the lock to
  * @fl: The lock to be applied
+ * @conflock: Place to return a copy of the conflicting lock, if found.
  *
  * Add a POSIX style lock to a file.
  * We merge adjacent & overlapping locks whenever possible.
@@ -1015,26 +1016,12 @@ static int __posix_lock_file_conf(struct inode *inode, struct file_lock *request
  * whether or not a lock was successfully freed by testing the return
  * value for -ENOENT.
  */
-int posix_lock_file(struct file *filp, struct file_lock *fl)
-{
-        return __posix_lock_file_conf(filp->f_path.dentry->d_inode, fl, NULL);
-}
-EXPORT_SYMBOL(posix_lock_file);
-
-/**
- * posix_lock_file_conf - Apply a POSIX-style lock to a file
- * @filp: The file to apply the lock to
- * @fl: The lock to be applied
- * @conflock: Place to return a copy of the conflicting lock, if found.
- *
- * Except for the conflock parameter, acts just like posix_lock_file.
- */
-int posix_lock_file_conf(struct file *filp, struct file_lock *fl,
+int posix_lock_file(struct file *filp, struct file_lock *fl,
                         struct file_lock *conflock)
 {
-        return __posix_lock_file_conf(filp->f_path.dentry->d_inode, fl, conflock);
+        return __posix_lock_file(filp->f_path.dentry->d_inode, fl, conflock);
 }
-EXPORT_SYMBOL(posix_lock_file_conf);
+EXPORT_SYMBOL(posix_lock_file);
 
 /**
  * posix_lock_file_wait - Apply a POSIX-style lock to a file
@@ -1050,7 +1037,7 @@ int posix_lock_file_wait(struct file *filp, struct file_lock *fl)
         int error;
         might_sleep ();
         for (;;) {
-                error = posix_lock_file(filp, fl);
+                error = posix_lock_file(filp, fl, NULL);
                 if ((error != -EAGAIN) || !(fl->fl_flags & FL_SLEEP))
                         break;
                 error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
@@ -1122,7 +1109,7 @@ int locks_mandatory_area(int read_write, struct inode *inode,
         fl.fl_end = offset + count - 1;
 
         for (;;) {
-                error = __posix_lock_file_conf(inode, &fl, NULL);
+                error = __posix_lock_file(inode, &fl, NULL);
                 if (error != -EAGAIN)
                         break;
                 if (!(fl.fl_flags & FL_SLEEP))
@@ -1610,12 +1597,62 @@ asmlinkage long sys_flock(unsigned int fd, unsigned int cmd)
         return error;
 }
 
+/**
+ * vfs_test_lock - test file byte range lock
+ * @filp: The file to test lock for
+ * @fl: The lock to test
+ * @conf: Place to return a copy of the conflicting lock, if found
+ *
+ * Returns -ERRNO on failure.  Indicates presence of conflicting lock by
+ * setting conf->fl_type to something other than F_UNLCK.
+ */
+int vfs_test_lock(struct file *filp, struct file_lock *fl)
+{
+        if (filp->f_op && filp->f_op->lock)
+                return filp->f_op->lock(filp, F_GETLK, fl);
+        posix_test_lock(filp, fl);
+        return 0;
+}
+EXPORT_SYMBOL_GPL(vfs_test_lock);
+
+static int posix_lock_to_flock(struct flock *flock, struct file_lock *fl)
+{
+        flock->l_pid = fl->fl_pid;
+#if BITS_PER_LONG == 32
+        /*
+         * Make sure we can represent the posix lock via
+         * legacy 32bit flock.
+         */
+        if (fl->fl_start > OFFT_OFFSET_MAX)
+                return -EOVERFLOW;
+        if (fl->fl_end != OFFSET_MAX && fl->fl_end > OFFT_OFFSET_MAX)
+                return -EOVERFLOW;
+#endif
+        flock->l_start = fl->fl_start;
+        flock->l_len = fl->fl_end == OFFSET_MAX ? 0 :
+                fl->fl_end - fl->fl_start + 1;
+        flock->l_whence = 0;
+        return 0;
+}
+
+#if BITS_PER_LONG == 32
+static void posix_lock_to_flock64(struct flock64 *flock, struct file_lock *fl)
+{
+        flock->l_pid = fl->fl_pid;
+        flock->l_start = fl->fl_start;
+        flock->l_len = fl->fl_end == OFFSET_MAX ? 0 :
+                fl->fl_end - fl->fl_start + 1;
+        flock->l_whence = 0;
+        flock->l_type = fl->fl_type;
+}
+#endif
+
 /* Report the first existing lock that would conflict with l.
  * This implements the F_GETLK command of fcntl().
  */
 int fcntl_getlk(struct file *filp, struct flock __user *l)
 {
-        struct file_lock *fl, cfl, file_lock;
+        struct file_lock file_lock;
         struct flock flock;
         int error;
 
@@ -1630,38 +1667,15 @@ int fcntl_getlk(struct file *filp, struct flock __user *l)
         if (error)
                 goto out;
 
-        if (filp->f_op && filp->f_op->lock) {
-                error = filp->f_op->lock(filp, F_GETLK, &file_lock);
-                if (file_lock.fl_ops && file_lock.fl_ops->fl_release_private)
-                        file_lock.fl_ops->fl_release_private(&file_lock);
-                if (error < 0)
-                        goto out;
-                else
-                  fl = (file_lock.fl_type == F_UNLCK ? NULL : &file_lock);
-        } else {
-                fl = (posix_test_lock(filp, &file_lock, &cfl) ? &cfl : NULL);
-        }
+        error = vfs_test_lock(filp, &file_lock);
+        if (error)
+                goto out;
  
-        flock.l_type = F_UNLCK;
-        if (fl != NULL) {
-                flock.l_pid = fl->fl_pid;
-#if BITS_PER_LONG == 32
-                /*
-                 * Make sure we can represent the posix lock via
-                 * legacy 32bit flock.
-                 */
-                error = -EOVERFLOW;
-                if (fl->fl_start > OFFT_OFFSET_MAX)
-                        goto out;
-                if ((fl->fl_end != OFFSET_MAX)
-                    && (fl->fl_end > OFFT_OFFSET_MAX))
+        flock.l_type = file_lock.fl_type;
+        if (file_lock.fl_type != F_UNLCK) {
+                error = posix_lock_to_flock(&flock, &file_lock);
+                if (error)
                         goto out;
-#endif
-                flock.l_start = fl->fl_start;
-                flock.l_len = fl->fl_end == OFFSET_MAX ? 0 :
-                        fl->fl_end - fl->fl_start + 1;
-                flock.l_whence = 0;
-                flock.l_type = fl->fl_type;
         }
         error = -EFAULT;
         if (!copy_to_user(l, &flock, sizeof(flock)))
@@ -1670,6 +1684,48 @@ out:
         return error;
 }
 
+/**
+ * vfs_lock_file - file byte range lock
+ * @filp: The file to apply the lock to
+ * @cmd: type of locking operation (F_SETLK, F_GETLK, etc.)
+ * @fl: The lock to be applied
+ * @conf: Place to return a copy of the conflicting lock, if found.
+ *
+ * A caller that doesn't care about the conflicting lock may pass NULL
+ * as the final argument.
+ *
+ * If the filesystem defines a private ->lock() method, then @conf will
+ * be left unchanged; so a caller that cares should initialize it to
+ * some acceptable default.
+ *
+ * To avoid blocking kernel daemons, such as lockd, that need to acquire POSIX
+ * locks, the ->lock() interface may return asynchronously, before the lock has
+ * been granted or denied by the underlying filesystem, if (and only if)
+ * fl_grant is set. Callers expecting ->lock() to return asynchronously
+ * will only use F_SETLK, not F_SETLKW; they will set FL_SLEEP if (and only if)
+ * the request is for a blocking lock. When ->lock() does return asynchronously,
+ * it must return -EINPROGRESS, and call ->fl_grant() when the lock
+ * request completes.
+ * If the request is for non-blocking lock the file system should return
+ * -EINPROGRESS then try to get the lock and call the callback routine with
+ * the result. If the request timed out the callback routine will return a
+ * nonzero return code and the file system should release the lock. The file
+ * system is also responsible to keep a corresponding posix lock when it
+ * grants a lock so the VFS can find out which locks are locally held and do
+ * the correct lock cleanup when required.
+ * The underlying filesystem must not drop the kernel lock or call
+ * ->fl_grant() before returning to the caller with a -EINPROGRESS
+ * return code.
+ */
+int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl, struct file_lock *conf)
+{
+        if (filp->f_op && filp->f_op->lock)
+                return filp->f_op->lock(filp, cmd, fl);
+        else
+                return posix_lock_file(filp, fl, conf);
+}
+EXPORT_SYMBOL_GPL(vfs_lock_file);
+
 /* Apply the lock described by l to an open file descriptor.
  * This implements both the F_SETLK and F_SETLKW commands of fcntl().
  */
@@ -1732,21 +1788,17 @@ again:
         if (error)
                 goto out;
 
-        if (filp->f_op && filp->f_op->lock != NULL)
-                error = filp->f_op->lock(filp, cmd, file_lock);
-        else {
-                for (;;) {
-                        error = posix_lock_file(filp, file_lock);
-                        if ((error != -EAGAIN) || (cmd == F_SETLK))
-                                break;
-                        error = wait_event_interruptible(file_lock->fl_wait,
-                                        !file_lock->fl_next);
-                        if (!error)
-                                continue;
-
-                        locks_delete_block(file_lock);
+        for (;;) {
+                error = vfs_lock_file(filp, cmd, file_lock, NULL);
+                if (error != -EAGAIN || cmd == F_SETLK)
                         break;
-                }
+                error = wait_event_interruptible(file_lock->fl_wait,
+                                !file_lock->fl_next);
+                if (!error)
+                        continue;
+
+                locks_delete_block(file_lock);
+                break;
         }
 
         /*
@@ -1769,7 +1821,7 @@ out:
  */
 int fcntl_getlk64(struct file *filp, struct flock64 __user *l)
 {
-        struct file_lock *fl, cfl, file_lock;
+        struct file_lock file_lock;
         struct flock64 flock;
         int error;
 
@@ -1784,27 +1836,14 @@ int fcntl_getlk64(struct file *filp, struct flock64 __user *l)
         if (error)
                 goto out;
 
-        if (filp->f_op && filp->f_op->lock) {
-                error = filp->f_op->lock(filp, F_GETLK, &file_lock);
-                if (file_lock.fl_ops && file_lock.fl_ops->fl_release_private)
-                        file_lock.fl_ops->fl_release_private(&file_lock);
-                if (error < 0)
-                        goto out;
-                else
-                  fl = (file_lock.fl_type == F_UNLCK ? NULL : &file_lock);
-        } else {
-                fl = (posix_test_lock(filp, &file_lock, &cfl) ? &cfl : NULL);
-        }
- 
-        flock.l_type = F_UNLCK;
-        if (fl != NULL) {
-                flock.l_pid = fl->fl_pid;
-                flock.l_start = fl->fl_start;
-                flock.l_len = fl->fl_end == OFFSET_MAX ? 0 :
-                        fl->fl_end - fl->fl_start + 1;
-                flock.l_whence = 0;
-                flock.l_type = fl->fl_type;
-        }
+        error = vfs_test_lock(filp, &file_lock);
+        if (error)
+                goto out;
+
+        flock.l_type = file_lock.fl_type;
+        if (file_lock.fl_type != F_UNLCK)
+                posix_lock_to_flock64(&flock, &file_lock);
+
         error = -EFAULT;
         if (!copy_to_user(l, &flock, sizeof(flock)))
                 error = 0;
@@ -1875,21 +1914,17 @@ again:
         if (error)
                 goto out;
 
-        if (filp->f_op && filp->f_op->lock != NULL)
-                error = filp->f_op->lock(filp, cmd, file_lock);
-        else {
-                for (;;) {
-                        error = posix_lock_file(filp, file_lock);
-                        if ((error != -EAGAIN) || (cmd == F_SETLK64))
-                                break;
-                        error = wait_event_interruptible(file_lock->fl_wait,
-                                        !file_lock->fl_next);
-                        if (!error)
-                                continue;
-
-                        locks_delete_block(file_lock);
+        for (;;) {
+                error = vfs_lock_file(filp, cmd, file_lock, NULL);
+                if (error != -EAGAIN || cmd == F_SETLK64)
                         break;
-                }
+                error = wait_event_interruptible(file_lock->fl_wait,
+                                !file_lock->fl_next);
+                if (!error)
+                        continue;
+
+                locks_delete_block(file_lock);
+                break;
         }
 
         /*
@@ -1934,10 +1969,7 @@ 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)
-                filp->f_op->lock(filp, F_SETLK, &lock);
-        else
-                posix_lock_file(filp, &lock);
+        vfs_lock_file(filp, F_SETLK, &lock, NULL);
 
         if (lock.fl_ops && lock.fl_ops->fl_release_private)
                 lock.fl_ops->fl_release_private(&lock);
@@ -2014,6 +2046,22 @@ posix_unblock_lock(struct file *filp, struct file_lock *waiter)
 
 EXPORT_SYMBOL(posix_unblock_lock);
 
+/**
+ * vfs_cancel_lock - file byte range unblock lock
+ * @filp: The file to apply the unblock to
+ * @fl: The lock to be unblocked
+ *
+ * Used by lock managers to cancel blocked requests
+ */
+int vfs_cancel_lock(struct file *filp, struct file_lock *fl)
+{
+        if (filp->f_op && filp->f_op->lock)
+                return filp->f_op->lock(filp, F_CANCELLK, fl);
+        return 0;
+}
+
+EXPORT_SYMBOL_GPL(vfs_cancel_lock);
+
 static void lock_get_status(char* out, struct file_lock *fl, int id, char *pfx)
 {
         struct inode *inode = NULL;