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author | Miklos Szeredi <miklos@szeredi.hu> | 2009-04-14 17:48:37 (GMT) |
---|---|---|
committer | Jens Axboe <jens.axboe@oracle.com> | 2009-04-15 10:10:11 (GMT) |
commit | 2933970b960223076d6affcf7a77e2bc546b8102 (patch) | |
tree | 1658b9692948b5118fc5fea29b83be4329c56b6e /fs | |
parent | b3c2d2ddd63944ef2a1e4a43077b602288107e01 (diff) | |
download | linux-fsl-qoriq-2933970b960223076d6affcf7a77e2bc546b8102.tar.xz |
splice: remove i_mutex locking in splice_from_pipe()
splice_from_pipe() is only called from two places:
- generic_splice_sendpage()
- splice_write_null()
Neither of these require i_mutex to be taken on the destination inode.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/splice.c | 18 |
1 files changed, 2 insertions, 16 deletions
diff --git a/fs/splice.c b/fs/splice.c index fd6b278..349576b 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -784,7 +784,7 @@ EXPORT_SYMBOL(__splice_from_pipe); * @actor: handler that splices the data * * Description: - * See __splice_from_pipe. This function locks the input and output inodes, + * See __splice_from_pipe. This function locks the pipe inode, * otherwise it's identical to __splice_from_pipe(). * */ @@ -793,7 +793,6 @@ ssize_t splice_from_pipe(struct pipe_inode_info *pipe, struct file *out, splice_actor *actor) { ssize_t ret; - struct inode *inode = out->f_mapping->host; struct splice_desc sd = { .total_len = len, .flags = flags, @@ -801,24 +800,11 @@ ssize_t splice_from_pipe(struct pipe_inode_info *pipe, struct file *out, .u.file = out, }; - /* - * The actor worker might be calling ->write_begin and - * ->write_end. Most of the time, these expect i_mutex to - * be held. Since this may result in an ABBA deadlock with - * pipe->inode, we have to order lock acquiry here. - * - * Outer lock must be inode->i_mutex, as pipe_wait() will - * release and reacquire pipe->inode->i_mutex, AND inode must - * never be a pipe. - */ - WARN_ON(S_ISFIFO(inode->i_mode)); - mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT); if (pipe->inode) - mutex_lock_nested(&pipe->inode->i_mutex, I_MUTEX_CHILD); + mutex_lock(&pipe->inode->i_mutex); ret = __splice_from_pipe(pipe, &sd, actor); if (pipe->inode) mutex_unlock(&pipe->inode->i_mutex); - mutex_unlock(&inode->i_mutex); return ret; } |