X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=fs%2Ffile.c;h=51aef675470fb64984733fe9a710adc7cb6b980a;hb=471b17e7ed0cb29338458eaa09103902891d802a;hp=55f4e70225631b275f85215ee543b104507caacc;hpb=d4965b3e2ff94d0c7b7e6e7e9794b54950a2f4b9;p=linux-2.6-omap-h63xx.git

diff --git a/fs/file.c b/fs/file.c
index 55f4e702256..51aef675470 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -21,7 +21,6 @@
 struct fdtable_defer {
 	spinlock_t lock;
 	struct work_struct wq;
-	struct timer_list timer;
 	struct fdtable *next;
 };
 
@@ -75,24 +74,10 @@ static void __free_fdtable(struct fdtable *fdt)
 	kfree(fdt);
 }
 
-static void fdtable_timer(unsigned long data)
-{
-	struct fdtable_defer *fddef = (struct fdtable_defer *)data;
-
-	spin_lock(&fddef->lock);
-	/*
-	 * If someone already emptied the queue return.
-	 */
-	if (!fddef->next)
-		goto out;
-	if (!schedule_work(&fddef->wq))
-		mod_timer(&fddef->timer, 5);
-out:
-	spin_unlock(&fddef->lock);
-}
-
-static void free_fdtable_work(struct fdtable_defer *f)
+static void free_fdtable_work(struct work_struct *work)
 {
+	struct fdtable_defer *f =
+		container_of(work, struct fdtable_defer, wq);
 	struct fdtable *fdt;
 
 	spin_lock_bh(&f->lock);
@@ -142,13 +127,8 @@ static void free_fdtable_rcu(struct rcu_head *rcu)
 		spin_lock(&fddef->lock);
 		fdt->next = fddef->next;
 		fddef->next = fdt;
-		/*
-		 * vmallocs are handled from the workqueue context.
-		 * If the per-cpu workqueue is running, then we
-		 * defer work scheduling through a timer.
-		 */
-		if (!schedule_work(&fddef->wq))
-			mod_timer(&fddef->timer, 5);
+		/* vmallocs are handled from the workqueue context */
+		schedule_work(&fddef->wq);
 		spin_unlock(&fddef->lock);
 		put_cpu_var(fdtable_defer_list);
 	}
@@ -240,13 +220,9 @@ static struct fdtable *alloc_fdtable(int nr)
 	if (!fdt)
   		goto out;
 
-	nfds = 8 * L1_CACHE_BYTES;
-  	/* Expand to the max in easy steps */
-  	while (nfds <= nr) {
-		nfds = nfds * 2;
-		if (nfds > NR_OPEN)
-			nfds = NR_OPEN;
-	}
+	nfds = max_t(int, 8 * L1_CACHE_BYTES, roundup_pow_of_two(nr + 1));
+	if (nfds > NR_OPEN)
+		nfds = NR_OPEN;
 
   	new_openset = alloc_fdset(nfds);
   	new_execset = alloc_fdset(nfds);
@@ -277,96 +253,85 @@ static struct fdtable *alloc_fdtable(int nr)
 	} while (nfds <= nr);
 	new_fds = alloc_fd_array(nfds);
 	if (!new_fds)
-		goto out;
+		goto out2;
 	fdt->fd = new_fds;
 	fdt->max_fds = nfds;
 	fdt->free_files = NULL;
 	return fdt;
+out2:
+	nfds = fdt->max_fdset;
 out:
-  	if (new_openset)
-  		free_fdset(new_openset, nfds);
-  	if (new_execset)
-  		free_fdset(new_execset, nfds);
+	free_fdset(new_openset, nfds);
+	free_fdset(new_execset, nfds);
 	kfree(fdt);
 	return NULL;
 }
 
 /*
- * Expands the file descriptor table - it will allocate a new fdtable and
- * both fd array and fdset. It is expected to be called with the
- * files_lock held.
+ * Expand the file descriptor table.
+ * This function will allocate a new fdtable and both fd array and fdset, of
+ * the given size.
+ * Return <0 error code on error; 1 on successful completion.
+ * The files->file_lock should be held on entry, and will be held on exit.
  */
 static int expand_fdtable(struct files_struct *files, int nr)
 	__releases(files->file_lock)
 	__acquires(files->file_lock)
 {
-	int error = 0;
-	struct fdtable *fdt;
-	struct fdtable *nfdt = NULL;
+	struct fdtable *new_fdt, *cur_fdt;
 
 	spin_unlock(&files->file_lock);
-	nfdt = alloc_fdtable(nr);
-	if (!nfdt) {
-		error = -ENOMEM;
-		spin_lock(&files->file_lock);
-		goto out;
-	}
-
+	new_fdt = alloc_fdtable(nr);
 	spin_lock(&files->file_lock);
-	fdt = files_fdtable(files);
+	if (!new_fdt)
+		return -ENOMEM;
 	/*
-	 * Check again since another task may have expanded the
-	 * fd table while we dropped the lock
+	 * Check again since another task may have expanded the fd table while
+	 * we dropped the lock
 	 */
-	if (nr >= fdt->max_fds || nr >= fdt->max_fdset) {
-		copy_fdtable(nfdt, fdt);
+	cur_fdt = files_fdtable(files);
+	if (nr >= cur_fdt->max_fds || nr >= cur_fdt->max_fdset) {
+		/* Continue as planned */
+		copy_fdtable(new_fdt, cur_fdt);
+		rcu_assign_pointer(files->fdt, new_fdt);
+		free_fdtable(cur_fdt);
 	} else {
-		/* Somebody expanded while we dropped file_lock */
-		spin_unlock(&files->file_lock);
-		__free_fdtable(nfdt);
-		spin_lock(&files->file_lock);
-		goto out;
+		/* Somebody else expanded, so undo our attempt */
+		__free_fdtable(new_fdt);
 	}
-	rcu_assign_pointer(files->fdt, nfdt);
-	free_fdtable(fdt);
-out:
-	return error;
+	return 1;
 }
 
 /*
  * Expand files.
- * Return <0 on error; 0 nothing done; 1 files expanded, we may have blocked.
- * Should be called with the files->file_lock spinlock held for write.
+ * This function will expand the file structures, if the requested size exceeds
+ * the current capacity and there is room for expansion.
+ * Return <0 error code on error; 0 when nothing done; 1 when files were
+ * expanded and execution may have blocked.
+ * The files->file_lock should be held on entry, and will be held on exit.
  */
 int expand_files(struct files_struct *files, int nr)
 {
-	int err, expand = 0;
 	struct fdtable *fdt;
 
 	fdt = files_fdtable(files);
-	if (nr >= fdt->max_fdset || nr >= fdt->max_fds) {
-		if (fdt->max_fdset >= NR_OPEN ||
-			fdt->max_fds >= NR_OPEN || nr >= NR_OPEN) {
-			err = -EMFILE;
-			goto out;
-		}
-		expand = 1;
-		if ((err = expand_fdtable(files, nr)))
-			goto out;
-	}
-	err = expand;
-out:
-	return err;
+	/* Do we need to expand? */
+	if (nr < fdt->max_fdset && nr < fdt->max_fds)
+		return 0;
+	/* Can we expand? */
+	if (fdt->max_fdset >= NR_OPEN || fdt->max_fds >= NR_OPEN ||
+	    nr >= NR_OPEN)
+		return -EMFILE;
+
+	/* All good, so we try */
+	return expand_fdtable(files, nr);
 }
 
 static void __devinit fdtable_defer_list_init(int cpu)
 {
 	struct fdtable_defer *fddef = &per_cpu(fdtable_defer_list, cpu);
 	spin_lock_init(&fddef->lock);
-	INIT_WORK(&fddef->wq, (void (*)(void *))free_fdtable_work, fddef);
-	init_timer(&fddef->timer);
-	fddef->timer.data = (unsigned long)fddef;
-	fddef->timer.function = fdtable_timer;
+	INIT_WORK(&fddef->wq, free_fdtable_work);
 	fddef->next = NULL;
 }