From: Hao Xu <[email protected]>
To: [email protected]
Cc: Jens Axboe <[email protected]>,
Pavel Begunkov <[email protected]>,
[email protected],
Alexander Viro <[email protected]>,
Andrew Morton <[email protected]>,
Luis Chamberlain <[email protected]>,
Kuniyuki Iwashima <[email protected]>
Subject: [PATCH 2/5] pipe: add trylock helpers for pipe lock
Date: Tue, 7 Jun 2022 16:06:16 +0800 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
From: Hao Xu <[email protected]>
Add two helpers pipe_trylock() and pipe_double_trylock(), they are used
in nonblock splice(pipe to pipe) scenario in next patches.
Signed-off-by: Hao Xu <[email protected]>
---
fs/pipe.c | 29 +++++++++++++++++++++++++++++
include/linux/pipe_fs_i.h | 2 ++
2 files changed, 31 insertions(+)
diff --git a/fs/pipe.c b/fs/pipe.c
index 74ae9fafd25a..033736eb61fb 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -98,6 +98,11 @@ void pipe_unlock(struct pipe_inode_info *pipe)
}
EXPORT_SYMBOL(pipe_unlock);
+int pipe_trylock(struct pipe_inode_info *pipe)
+{
+ return mutex_trylock(&pipe->mutex);
+}
+
static inline void __pipe_lock(struct pipe_inode_info *pipe)
{
mutex_lock_nested(&pipe->mutex, I_MUTEX_PARENT);
@@ -122,6 +127,30 @@ void pipe_double_lock(struct pipe_inode_info *pipe1,
}
}
+int pipe_double_trylock(struct pipe_inode_info *pipe1,
+ struct pipe_inode_info *pipe2)
+{
+ BUG_ON(pipe1 == pipe2);
+
+ if (pipe1 < pipe2) {
+ if (!pipe_trylock(pipe1))
+ return 0;
+ if (!pipe_trylock(pipe2)) {
+ pipe_unlock(pipe1);
+ return 0;
+ }
+ } else {
+ if (!pipe_trylock(pipe2))
+ return 0;
+ if (!pipe_trylock(pipe1)) {
+ pipe_unlock(pipe2);
+ return 0;
+ }
+ }
+
+ return 1;
+}
+
static void anon_pipe_buf_release(struct pipe_inode_info *pipe,
struct pipe_buffer *buf)
{
diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
index cb0fd633a610..78dc2c7c999f 100644
--- a/include/linux/pipe_fs_i.h
+++ b/include/linux/pipe_fs_i.h
@@ -235,8 +235,10 @@ static inline bool pipe_buf_try_steal(struct pipe_inode_info *pipe,
/* Pipe lock and unlock operations */
void pipe_lock(struct pipe_inode_info *);
+int pipe_trylock(struct pipe_inode_info *);
void pipe_unlock(struct pipe_inode_info *);
void pipe_double_lock(struct pipe_inode_info *, struct pipe_inode_info *);
+int pipe_double_trylock(struct pipe_inode_info *, struct pipe_inode_info *);
/* Wait for a pipe to be readable/writable while dropping the pipe lock */
void pipe_wait_readable(struct pipe_inode_info *);
--
2.25.1
next prev parent reply other threads:[~2022-06-07 8:06 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-07 8:06 [RFC 0/5] support nonblock submission for splice pipe to pipe Hao Xu
2022-06-07 8:06 ` [PATCH 1/5] io_uring: move sp->len check up for splice and tee Hao Xu
2022-06-07 8:06 ` Hao Xu [this message]
2022-06-07 8:06 ` [PATCH 3/5] splice: support nonblock for splice from pipe to pipe Hao Xu
2022-06-07 8:06 ` [PATCH 4/5] io_uring: support nonblock try for splicing " Hao Xu
2022-06-07 21:38 ` kernel test robot
2022-06-08 14:18 ` kernel test robot
2022-06-09 2:24 ` kernel test robot
2022-06-07 8:06 ` [PATCH 5/5] io_uring: add file_in in io_splice{} to avoid duplicate calculation Hao Xu
2022-06-07 8:13 ` [RFC 0/5] support nonblock submission for splice pipe to pipe Hao Xu
2022-06-07 9:27 ` Pavel Begunkov
2022-06-08 4:19 ` Hao Xu
2022-06-08 4:31 ` Jens Axboe
2022-06-08 11:33 ` Pavel Begunkov
2022-06-14 13:23 ` Hao Xu
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