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>
Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Willy Tarreau <w@1wt.eu>
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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 23 insertions, 22 deletions

diff --git a/fs/pipe.c b/fs/pipe.c
index dc5f4c040890..eaa3c8d36291 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -622,33 +622,34 @@ 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;
 }