Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs pile 1 from Al Viro:
 "This is _not_ all; in particular, Miklos' and Jan's stuff is not there
  yet."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (64 commits)
  ext4: initialization of ext4_li_mtx needs to be done earlier
  debugfs-related mode_t whack-a-mole
  hfsplus: add an ioctl to bless files
  hfsplus: change finder_info to u32
  hfsplus: initialise userflags
  qnx4: new helper - try_extent()
  qnx4: get rid of qnx4_bread/qnx4_getblk
  take removal of PF_FORKNOEXEC to flush_old_exec()
  trim includes in inode.c
  um: uml_dup_mmap() relies on ->mmap_sem being held, but activate_mm() doesn't hold it
  um: embed ->stub_pages[] into mmu_context
  gadgetfs: list_for_each_safe() misuse
  ocfs2: fix leaks on failure exits in module_init
  ecryptfs: make register_filesystem() the last potential failure exit
  ntfs: forgets to unregister sysctls on register_filesystem() failure
  logfs: missing cleanup on register_filesystem() failure
  jfs: mising cleanup on register_filesystem() failure
  make configfs_pin_fs() return root dentry on success
  configfs: configfs_create_dir() has parent dentry in dentry->d_parent
  configfs: sanitize configfs_create()
  ...

1 files changed, 22 insertions, 43 deletions

diff --git a/fs/aio.c b/fs/aio.c
index 5b600cb8779..c7acaf3167a 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -199,16 +199,7 @@ static int aio_setup_ring(struct kioctx *ctx)
 static void ctx_rcu_free(struct rcu_head *head)
 {
 	struct kioctx *ctx = container_of(head, struct kioctx, rcu_head);
-	unsigned nr_events = ctx->max_reqs;
-
 	kmem_cache_free(kioctx_cachep, ctx);
-
-	if (nr_events) {
-		spin_lock(&aio_nr_lock);
-		BUG_ON(aio_nr - nr_events > aio_nr);
-		aio_nr -= nr_events;
-		spin_unlock(&aio_nr_lock);
-	}
 }
 
 /* __put_ioctx
@@ -217,13 +208,19 @@ static void ctx_rcu_free(struct rcu_head *head)
  */
 static void __put_ioctx(struct kioctx *ctx)
 {
+	unsigned nr_events = ctx->max_reqs;
 	BUG_ON(ctx->reqs_active);
 
-	cancel_delayed_work(&ctx->wq);
-	cancel_work_sync(&ctx->wq.work);
+	cancel_delayed_work_sync(&ctx->wq);
 	aio_free_ring(ctx);
 	mmdrop(ctx->mm);
 	ctx->mm = NULL;
+	if (nr_events) {
+		spin_lock(&aio_nr_lock);
+		BUG_ON(aio_nr - nr_events > aio_nr);
+		aio_nr -= nr_events;
+		spin_unlock(&aio_nr_lock);
+	}
 	pr_debug("__put_ioctx: freeing %p\n", ctx);
 	call_rcu(&ctx->rcu_head, ctx_rcu_free);
 }
@@ -247,7 +244,7 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
 {
 	struct mm_struct *mm;
 	struct kioctx *ctx;
-	int did_sync = 0;
+	int err = -ENOMEM;
 
 	/* Prevent overflows */
 	if ((nr_events > (0x10000000U / sizeof(struct io_event))) ||
@@ -256,7 +253,7 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
 		return ERR_PTR(-EINVAL);
 	}
 
-	if ((unsigned long)nr_events > aio_max_nr)
+	if (!nr_events || (unsigned long)nr_events > aio_max_nr)
 		return ERR_PTR(-EAGAIN);
 
 	ctx = kmem_cache_zalloc(kioctx_cachep, GFP_KERNEL);
@@ -280,25 +277,14 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
 		goto out_freectx;
 
 	/* limit the number of system wide aios */
-	do {
-		spin_lock_bh(&aio_nr_lock);
-		if (aio_nr + nr_events > aio_max_nr ||
-		    aio_nr + nr_events < aio_nr)
-			ctx->max_reqs = 0;
-		else
-			aio_nr += ctx->max_reqs;
-		spin_unlock_bh(&aio_nr_lock);
-		if (ctx->max_reqs || did_sync)
-			break;
-
-		/* wait for rcu callbacks to have completed before giving up */
-		synchronize_rcu();
-		did_sync = 1;
-		ctx->max_reqs = nr_events;
-	} while (1);
-
-	if (ctx->max_reqs == 0)
+	spin_lock(&aio_nr_lock);
+	if (aio_nr + nr_events > aio_max_nr ||
+	    aio_nr + nr_events < aio_nr) {
+		spin_unlock(&aio_nr_lock);
 		goto out_cleanup;
+	}
+	aio_nr += ctx->max_reqs;
+	spin_unlock(&aio_nr_lock);
 
 	/* now link into global list. */
 	spin_lock(&mm->ioctx_lock);
@@ -310,16 +296,13 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
 	return ctx;
 
 out_cleanup:
-	__put_ioctx(ctx);
-	return ERR_PTR(-EAGAIN);
-
+	err = -EAGAIN;
+	aio_free_ring(ctx);
 out_freectx:
 	mmdrop(mm);
 	kmem_cache_free(kioctx_cachep, ctx);
-	ctx = ERR_PTR(-ENOMEM);
-
-	dprintk("aio: error allocating ioctx %p\n", ctx);
-	return ctx;
+	dprintk("aio: error allocating ioctx %d\n", err);
+	return ERR_PTR(err);
 }
 
 /* aio_cancel_all
@@ -407,10 +390,6 @@ void exit_aio(struct mm_struct *mm)
 		aio_cancel_all(ctx);
 
 		wait_for_all_aios(ctx);
-		/*
-		 * Ensure we don't leave the ctx on the aio_wq
-		 */
-		cancel_work_sync(&ctx->wq.work);
 
 		if (1 != atomic_read(&ctx->users))
 			printk(KERN_DEBUG
@@ -920,7 +899,7 @@ static void aio_kick_handler(struct work_struct *work)
  	unuse_mm(mm);
 	set_fs(oldfs);
 	/*
-	 * we're in a worker thread already, don't use queue_delayed_work,
+	 * we're in a worker thread already; no point using non-zero delay
 	 */
 	if (requeue)
 		queue_delayed_work(aio_wq, &ctx->wq, 0);