diff options
| author | Jan Kara <jack@suse.cz> | 2016-10-07 16:56:55 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-07 18:46:26 -0700 |
| commit | 073f65522aeb23e46fc8a809d69513132d3acc81 (patch) | |
| tree | 628b7586e7f70ba13b6ccff48efbbec571fde8b7 /fs | |
| parent | c21dbe20f606219fe54faf555b7bc5565487c58f (diff) | |
| download | linux-073f65522aeb23e46fc8a809d69513132d3acc81.tar.bz2 | |
fanotify: use notification_lock instead of access_lock
Fanotify code has its own lock (access_lock) to protect a list of events
waiting for a response from userspace.
However this is somewhat awkward as the same list_head in the event is
protected by notification_lock if it is part of the notification queue
and by access_lock if it is part of the fanotify private queue which
makes it difficult for any reliable checks in the generic code. So make
fanotify use the same lock - notification_lock - for protecting its
private event list.
Link: http://lkml.kernel.org/r/1473797711-14111-6-git-send-email-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/notify/fanotify/fanotify_user.c | 13 |
1 files changed, 5 insertions, 8 deletions
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 80091a5dc8c0..189fab3ac4e6 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -148,7 +148,7 @@ static struct fanotify_perm_event_info *dequeue_event( { struct fanotify_perm_event_info *event, *return_e = NULL; - spin_lock(&group->fanotify_data.access_lock); + spin_lock(&group->notification_lock); list_for_each_entry(event, &group->fanotify_data.access_list, fae.fse.list) { if (event->fd != fd) @@ -158,7 +158,7 @@ static struct fanotify_perm_event_info *dequeue_event( return_e = event; break; } - spin_unlock(&group->fanotify_data.access_lock); + spin_unlock(&group->notification_lock); pr_debug("%s: found return_re=%p\n", __func__, return_e); @@ -310,10 +310,10 @@ static ssize_t fanotify_read(struct file *file, char __user *buf, wake_up(&group->fanotify_data.access_waitq); break; } - spin_lock(&group->fanotify_data.access_lock); + spin_lock(&group->notification_lock); list_add_tail(&kevent->list, &group->fanotify_data.access_list); - spin_unlock(&group->fanotify_data.access_lock); + spin_unlock(&group->notification_lock); #endif } buf += ret; @@ -372,7 +372,7 @@ static int fanotify_release(struct inode *ignored, struct file *file) * Process all permission events on access_list and notification queue * and simulate reply from userspace. */ - spin_lock(&group->fanotify_data.access_lock); + spin_lock(&group->notification_lock); list_for_each_entry_safe(event, next, &group->fanotify_data.access_list, fae.fse.list) { pr_debug("%s: found group=%p event=%p\n", __func__, group, @@ -381,14 +381,12 @@ static int fanotify_release(struct inode *ignored, struct file *file) list_del_init(&event->fae.fse.list); event->response = FAN_ALLOW; } - spin_unlock(&group->fanotify_data.access_lock); /* * Destroy all non-permission events. For permission events just * dequeue them and set the response. They will be freed once the * response is consumed and fanotify_get_response() returns. */ - spin_lock(&group->notification_lock); while (!fsnotify_notify_queue_is_empty(group)) { fsn_event = fsnotify_remove_first_event(group); if (!(fsn_event->mask & FAN_ALL_PERM_EVENTS)) { @@ -768,7 +766,6 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) event_f_flags |= O_LARGEFILE; group->fanotify_data.f_flags = event_f_flags; #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS - spin_lock_init(&group->fanotify_data.access_lock); init_waitqueue_head(&group->fanotify_data.access_waitq); INIT_LIST_HEAD(&group->fanotify_data.access_list); #endif |