[PATCH 3.16 203/410] pipe: simplify logic in alloc_pipe_info()
From: Ben Hutchings
Date: Thu Jun 07 2018 - 10:32:20 EST
3.16.57-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: "Michael Kerrisk (man-pages)" <mtk.manpages@xxxxxxxxx>
commit 09b4d1990094dd22c27fb0163534db419458569c upstream.
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@xxxxxxxxx
Signed-off-by: Michael Kerrisk <mtk.manpages@xxxxxxxxx>
Reviewed-by: Vegard Nossum <vegard.nossum@xxxxxxxxxx>
Cc: Willy Tarreau <w@xxxxxx>
Cc: <socketpair@xxxxxxxxx>
Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
[bwh: Backported to 3.16:
- Don't use GFP_KERNEL_ACCOUNT
- Adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -611,31 +611,34 @@ static bool too_many_pipe_buffers_hard(s
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);
- if (pipe) {
- unsigned long pipe_bufs = PIPE_DEF_BUFFERS;
- struct user_struct *user = get_current_user();
+ 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 = kzalloc(sizeof(struct pipe_buffer) * pipe_bufs, GFP_KERNEL);
- }
+ 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);
+ }
- 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;
}