diff options
| author | Miklos Szeredi <miklos@szeredi.hu> | 2009-04-14 19:48:38 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-05-19 22:20:15 -0700 |
| commit | 1763c368233c8ebf9c5596cb3230a0e4942459b4 (patch) | |
| tree | 9ad1f7a0e1fecf39dc7d58d0bc9d1ffd638201f6 | |
| parent | dbda7d1d8a375ec42a6f7602263ec854d9fd7245 (diff) | |
splice: fix i_mutex locking in generic_splice_write()
commit eb443e5a25d43996deb62b9bcee1a4ce5dea2ead upstream.
Rearrange locking of i_mutex on destination so it's only held while
buffers are copied with the pipe_to_file() actor, and not while
waiting for more data on the pipe.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | fs/splice.c | 34 |
1 files changed, 23 insertions, 11 deletions
diff --git a/fs/splice.c b/fs/splice.c index 483fa8cc4bc0..dcf7410c97db 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -893,17 +893,29 @@ generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out, }; ssize_t ret; - WARN_ON(S_ISFIFO(inode->i_mode)); - mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT); - ret = file_remove_suid(out); - if (likely(!ret)) { - if (pipe->inode) - mutex_lock_nested(&pipe->inode->i_mutex, I_MUTEX_CHILD); - ret = __splice_from_pipe(pipe, &sd, pipe_to_file); - if (pipe->inode) - mutex_unlock(&pipe->inode->i_mutex); - } - mutex_unlock(&inode->i_mutex); + if (pipe->inode) + mutex_lock_nested(&pipe->inode->i_mutex, I_MUTEX_PARENT); + + splice_from_pipe_begin(&sd); + do { + ret = splice_from_pipe_next(pipe, &sd); + if (ret <= 0) + break; + + mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD); + ret = file_remove_suid(out); + if (!ret) + ret = splice_from_pipe_feed(pipe, &sd, pipe_to_file); + mutex_unlock(&inode->i_mutex); + } while (ret > 0); + splice_from_pipe_end(pipe, &sd); + + if (pipe->inode) + mutex_unlock(&pipe->inode->i_mutex); + + if (sd.num_spliced) + ret = sd.num_spliced; + if (ret > 0) { unsigned long nr_pages; |