diff options
Diffstat (limited to 'fs/splice.c')
| -rw-r--r-- | fs/splice.c | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/fs/splice.c b/fs/splice.c index dd727d4..c18aa7e 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -737,10 +737,19 @@ ssize_t splice_from_pipe(struct pipe_inode_info *pipe, struct file *out, * ->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. */ - inode_double_lock(inode, pipe->inode); + 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); ret = __splice_from_pipe(pipe, &sd, actor); - inode_double_unlock(inode, pipe->inode); + if (pipe->inode) + mutex_unlock(&pipe->inode->i_mutex); + mutex_unlock(&inode->i_mutex); return ret; } @@ -831,11 +840,17 @@ generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out, }; ssize_t ret; - inode_double_lock(inode, pipe->inode); + 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 (likely(!ret)) { + if (pipe->inode) + mutex_lock_nested(&pipe->inode->i_mutex, I_MUTEX_CHILD); ret = __splice_from_pipe(pipe, &sd, pipe_to_file); - inode_double_unlock(inode, pipe->inode); + if (pipe->inode) + mutex_unlock(&pipe->inode->i_mutex); + } + mutex_unlock(&inode->i_mutex); if (ret > 0) { unsigned long nr_pages; |