Merge branch 'for-next' of git://git.infradead.org/users/eparis/notify

Pull filesystem notification updates from Eric Paris:
 "This pull mostly is about locking changes in the fsnotify system.  By
  switching the group lock from a spin_lock() to a mutex() we can now
  hold the lock across things like iput().  This fixes a problem
  involving unmounting a fs and having inodes be busy, first pointed out
  by FAT, but reproducible with tmpfs.

  This also restores signal driven I/O for inotify, which has been
  broken since about 2.6.32."

Ugh.  I *hate* the timing of this.  It was rebased after the merge
window opened, and then left to sit with the pull request coming the day
before the merge window closes.  That's just crap.  But apparently the
patches themselves have been around for over a year, just gathering
dust, so now it's suddenly critical.

Fixed up semantic conflict in fs/notify/fdinfo.c as per Stephen
Rothwell's fixes from -next.

* 'for-next' of git://git.infradead.org/users/eparis/notify:
  inotify: automatically restart syscalls
  inotify: dont skip removal of watch descriptor if creation of ignored event failed
  fanotify: dont merge permission events
  fsnotify: make fasync generic for both inotify and fanotify
  fsnotify: change locking order
  fsnotify: dont put marks on temporary list when clearing marks by group
  fsnotify: introduce locked versions of fsnotify_add_mark() and fsnotify_remove_mark()
  fsnotify: pass group to fsnotify_destroy_mark()
  fsnotify: use a mutex instead of a spinlock to protect a groups mark list
  fanotify: add an extra flag to mark_remove_from_mask that indicates wheather a mark should be destroyed
  fsnotify: take groups mark_lock before mark lock
  fsnotify: use reference counting for groups
  fsnotify: introduce fsnotify_get_group()
  inotify, fanotify: replace fsnotify_put_group() with fsnotify_destroy_group()

2 files changed, 17 insertions, 21 deletions

diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c
index e3cbd746f64a..871569c7d609 100644
--- a/fs/notify/inotify/inotify_fsnotify.c
+++ b/fs/notify/inotify/inotify_fsnotify.c
@@ -118,6 +118,7 @@ static int inotify_handle_event(struct fsnotify_group *group,
 
         fsn_event_priv = &event_priv->fsnotify_event_priv_data;
 
+        fsnotify_get_group(group);
         fsn_event_priv->group = group;
         event_priv->wd = wd;
 
@@ -131,7 +132,7 @@ static int inotify_handle_event(struct fsnotify_group *group,
         }
 
         if (inode_mark->mask & IN_ONESHOT)
-                fsnotify_destroy_mark(inode_mark);
+                fsnotify_destroy_mark(inode_mark, group);
 
         return ret;
 }
@@ -210,6 +211,7 @@ void inotify_free_event_priv(struct fsnotify_event_private_data *fsn_event_priv)
         event_priv = container_of(fsn_event_priv, struct inotify_event_private_data,
                                   fsnotify_event_priv_data);
 
+        fsnotify_put_group(fsn_event_priv->group);
         kmem_cache_free(event_priv_cachep, event_priv);
 }
 
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index 36cb013c7c13..228a2c2ad8d7 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -265,7 +265,7 @@ static ssize_t inotify_read(struct file *file, char __user *buf,
                 ret = -EAGAIN;
                 if (file->f_flags & O_NONBLOCK)
                         break;
-                ret = -EINTR;
+                ret = -ERESTARTSYS;
                 if (signal_pending(current))
                         break;
 
@@ -281,23 +281,17 @@ static ssize_t inotify_read(struct file *file, char __user *buf,
         return ret;
 }
 
-static int inotify_fasync(int fd, struct file *file, int on)
-{
-        struct fsnotify_group *group = file->private_data;
-
-        return fasync_helper(fd, file, on, &group->inotify_data.fa) >= 0 ? 0 : -EIO;
-}
-
 static int inotify_release(struct inode *ignored, struct file *file)
 {
         struct fsnotify_group *group = file->private_data;
 
         pr_debug("%s: group=%p\n", __func__, group);
 
-        fsnotify_clear_marks_by_group(group);
+        if (file->f_flags & FASYNC)
+                fsnotify_fasync(-1, file, 0);
 
         /* free this group, matching get was inotify_init->fsnotify_obtain_group */
-        fsnotify_put_group(group);
+        fsnotify_destroy_group(group);
 
         return 0;
 }
@@ -339,7 +333,7 @@ static const struct file_operations inotify_fops = {
         .show_fdinfo    = inotify_show_fdinfo,
         .poll           = inotify_poll,
         .read           = inotify_read,
-        .fasync         = inotify_fasync,
+        .fasync         = fsnotify_fasync,
         .release        = inotify_release,
         .unlocked_ioctl = inotify_ioctl,
         .compat_ioctl   = inotify_ioctl,
@@ -521,13 +515,13 @@ void inotify_ignored_and_remove_idr(struct fsnotify_mark *fsn_mark,
         struct fsnotify_event_private_data *fsn_event_priv;
         int ret;
 
+        i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
+
         ignored_event = fsnotify_create_event(NULL, FS_IN_IGNORED, NULL,
                                               FSNOTIFY_EVENT_NONE, NULL, 0,
                                               GFP_NOFS);
         if (!ignored_event)
-                return;
-
-        i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
+                goto skip_send_ignore;
 
         event_priv = kmem_cache_alloc(event_priv_cachep, GFP_NOFS);
         if (unlikely(!event_priv))
@@ -535,6 +529,7 @@ void inotify_ignored_and_remove_idr(struct fsnotify_mark *fsn_mark,
 
         fsn_event_priv = &event_priv->fsnotify_event_priv_data;
 
+        fsnotify_get_group(group);
         fsn_event_priv->group = group;
         event_priv->wd = i_mark->wd;
 
@@ -548,9 +543,9 @@ void inotify_ignored_and_remove_idr(struct fsnotify_mark *fsn_mark,
         }
 
 skip_send_ignore:
-
         /* matches the reference taken when the event was created */
-        fsnotify_put_event(ignored_event);
+        if (ignored_event)
+                fsnotify_put_event(ignored_event);
 
         /* remove this mark from the idr */
         inotify_remove_from_idr(group, i_mark);
@@ -709,12 +704,11 @@ static struct fsnotify_group *inotify_new_group(unsigned int max_events)
         spin_lock_init(&group->inotify_data.idr_lock);
         idr_init(&group->inotify_data.idr);
         group->inotify_data.last_wd = 0;
-        group->inotify_data.fa = NULL;
         group->inotify_data.user = get_current_user();
 
         if (atomic_inc_return(&group->inotify_data.user->inotify_devs) >
             inotify_max_user_instances) {
-                fsnotify_put_group(group);
+                fsnotify_destroy_group(group);
                 return ERR_PTR(-EMFILE);
         }
 
@@ -743,7 +737,7 @@ SYSCALL_DEFINE1(inotify_init1, int, flags)
         ret = anon_inode_getfd("inotify", &inotify_fops, group,
                                   O_RDONLY | flags);
         if (ret < 0)
-                fsnotify_put_group(group);
+                fsnotify_destroy_group(group);
 
         return ret;
 }
@@ -819,7 +813,7 @@ SYSCALL_DEFINE2(inotify_rm_watch, int, fd, __s32, wd)
 
         ret = 0;
 
-        fsnotify_destroy_mark(&i_mark->fsn_mark);
+        fsnotify_destroy_mark(&i_mark->fsn_mark, group);
 
         /* match ref taken by inotify_idr_find */
         fsnotify_put_mark(&i_mark->fsn_mark);