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Subject[PATCH v2 5/8] pipe: simplify logic in alloc_pipe_info()
Date
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())

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>
Cc: linux-api@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
---
fs/pipe.c | 45 +++++++++++++++++++++++----------------------
1 file changed, 23 insertions(+), 22 deletions(-)

diff --git a/fs/pipe.c b/fs/pipe.c
index f45a173..256fc5a 100644
--- 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;
}

--
2.5.5
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