pipe: simplify logic in alloc_pipe_info()

Replace an 'if' block that covers most of the code in this function
with a 'goto'. This makes the code a little simpler to read, and also
simplifies the next patch (fix limit checking in alloc_pipe_info())

Link: http://lkml.kernel.org/r/aef030c1-0257-98a9-4988-186efa48530c@gmail.com
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: <socketpair@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Jens Axboe <axboe@fb.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/pipe.c b/fs/pipe.c
index f45a1733faed998927a2a84253368e37129ab1a4..256fc5a290b2755b85e96dd1b28337c693918561 100644 (file)
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -625,33 +625,34 @@ static bool too_many_pipe_buffers_hard(struct user_struct *user)
 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();
 
        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 (!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->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) {
+               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;
        }
 
+       kfree(pipe);
+out_free_uid:
+       free_uid(user);
        return NULL;
 }