X-Git-Url: http://git.cascardo.info/?a=blobdiff_plain;f=fs%2Fpipe.c;h=8e0d9f26dfadc4b5849a9f46a933a89ea2aa49ca;hb=a442950d4af036006757bc3da00a2cb939fb2f59;hp=dc5f4c040890e9c53ff888623068cc376b2da496;hpb=b0b91d18e2e97b741b294af9333824ecc3fadfd8;p=cascardo%2Flinux.git

diff --git a/fs/pipe.c b/fs/pipe.c
index dc5f4c040890..8e0d9f26dfad 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -601,54 +601,63 @@ pipe_fasync(int fd, struct file *filp, int on)
 	return retval;
 }
 
-static void account_pipe_buffers(struct user_struct *user,
+static unsigned long account_pipe_buffers(struct user_struct *user,
                                  unsigned long old, unsigned long new)
 {
-	atomic_long_add(new - old, &user->pipe_bufs);
+	return atomic_long_add_return(new - old, &user->pipe_bufs);
 }
 
-static bool too_many_pipe_buffers_soft(struct user_struct *user)
+static bool too_many_pipe_buffers_soft(unsigned long user_bufs)
 {
-	return pipe_user_pages_soft &&
-	       atomic_long_read(&user->pipe_bufs) >= pipe_user_pages_soft;
+	return pipe_user_pages_soft && user_bufs >= pipe_user_pages_soft;
 }
 
-static bool too_many_pipe_buffers_hard(struct user_struct *user)
+static bool too_many_pipe_buffers_hard(unsigned long user_bufs)
 {
-	return pipe_user_pages_hard &&
-	       atomic_long_read(&user->pipe_bufs) >= pipe_user_pages_hard;
+	return pipe_user_pages_hard && user_bufs >= pipe_user_pages_hard;
 }
 
 struct pipe_inode_info *alloc_pipe_info(void)
 {
 	struct pipe_inode_info *pipe;
+	unsigned long pipe_bufs = PIPE_DEF_BUFFERS;
+	struct user_struct *user = get_current_user();
+	unsigned long user_bufs;
 
 	pipe = kzalloc(sizeof(struct pipe_inode_info), GFP_KERNEL_ACCOUNT);
-	if (pipe) {
-		unsigned long pipe_bufs = PIPE_DEF_BUFFERS;
-		struct user_struct *user = get_current_user();
-
-		if (!too_many_pipe_buffers_hard(user)) {
-			if (too_many_pipe_buffers_soft(user))
-				pipe_bufs = 1;
-			pipe->bufs = kcalloc(pipe_bufs,
-					     sizeof(struct pipe_buffer),
-					     GFP_KERNEL_ACCOUNT);
-		}
+	if (pipe == NULL)
+		goto out_free_uid;
 
-		if (pipe->bufs) {
-			init_waitqueue_head(&pipe->wait);
-			pipe->r_counter = pipe->w_counter = 1;
-			pipe->buffers = pipe_bufs;
-			pipe->user = user;
-			account_pipe_buffers(user, 0, pipe_bufs);
-			mutex_init(&pipe->mutex);
-			return pipe;
-		}
-		free_uid(user);
-		kfree(pipe);
+	if (pipe_bufs * PAGE_SIZE > pipe_max_size && !capable(CAP_SYS_RESOURCE))
+		pipe_bufs = pipe_max_size >> PAGE_SHIFT;
+
+	user_bufs = account_pipe_buffers(user, 0, pipe_bufs);
+
+	if (too_many_pipe_buffers_soft(user_bufs)) {
+		user_bufs = account_pipe_buffers(user, pipe_bufs, 1);
+		pipe_bufs = 1;
 	}
 
+	if (too_many_pipe_buffers_hard(user_bufs))
+		goto out_revert_acct;
+
+	pipe->bufs = kcalloc(pipe_bufs, sizeof(struct pipe_buffer),
+			     GFP_KERNEL_ACCOUNT);
+
+	if (pipe->bufs) {
+		init_waitqueue_head(&pipe->wait);
+		pipe->r_counter = pipe->w_counter = 1;
+		pipe->buffers = pipe_bufs;
+		pipe->user = user;
+		mutex_init(&pipe->mutex);
+		return pipe;
+	}
+
+out_revert_acct:
+	(void) account_pipe_buffers(user, pipe_bufs, 0);
+	kfree(pipe);
+out_free_uid:
+	free_uid(user);
 	return NULL;
 }
 
@@ -656,7 +665,7 @@ void free_pipe_info(struct pipe_inode_info *pipe)
 {
 	int i;
 
-	account_pipe_buffers(pipe->user, pipe->buffers, 0);
+	(void) account_pipe_buffers(pipe->user, pipe->buffers, 0);
 	free_uid(pipe->user);
 	for (i = 0; i < pipe->buffers; i++) {
 		struct pipe_buffer *buf = pipe->bufs + i;
@@ -1027,6 +1036,7 @@ static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long arg)
 {
 	struct pipe_buffer *bufs;
 	unsigned int size, nr_pages;
+	unsigned long user_bufs;
 	long ret = 0;
 
 	size = round_pipe_size(arg);
@@ -1046,11 +1056,11 @@ static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long arg)
 			size > pipe_max_size && !capable(CAP_SYS_RESOURCE))
 		return -EPERM;
 
-	account_pipe_buffers(pipe->user, pipe->buffers, nr_pages);
+	user_bufs = account_pipe_buffers(pipe->user, pipe->buffers, nr_pages);
 
 	if (nr_pages > pipe->buffers &&
-			(too_many_pipe_buffers_hard(pipe->user) ||
-			 too_many_pipe_buffers_soft(pipe->user)) &&
+			(too_many_pipe_buffers_hard(user_bufs) ||
+			 too_many_pipe_buffers_soft(user_bufs)) &&
 			!capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN)) {
 		ret = -EPERM;
 		goto out_revert_acct;
@@ -1102,7 +1112,7 @@ static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long arg)
 	return nr_pages * PAGE_SIZE;
 
 out_revert_acct:
-	account_pipe_buffers(pipe->user, nr_pages, pipe->buffers);
+	(void) account_pipe_buffers(pipe->user, nr_pages, pipe->buffers);
 	return ret;
 }