diff options
| -rw-r--r-- | sys/kern/sys_pipe.c | 37 |
1 files changed, 28 insertions, 9 deletions
diff --git a/sys/kern/sys_pipe.c b/sys/kern/sys_pipe.c index 2b6eb66..9a4448a 100644 --- a/sys/kern/sys_pipe.c +++ b/sys/kern/sys_pipe.c @@ -569,12 +569,7 @@ pipe_create(pipe, backing) /* If we're not backing this pipe, no need to do anything. */ error = 0; } - if (error == 0) { - pipe->pipe_ino = alloc_unr(pipeino_unr); - if (pipe->pipe_ino == -1) - /* pipeclose will clear allocated kva */ - error = ENOMEM; - } + pipe->pipe_ino = -1; return (error); } @@ -1398,16 +1393,40 @@ pipe_stat(fp, ub, active_cred, td) struct ucred *active_cred; struct thread *td; { - struct pipe *pipe = fp->f_data; + struct pipe *pipe; + int new_unr; #ifdef MAC int error; +#endif + pipe = fp->f_data; PIPE_LOCK(pipe); +#ifdef MAC error = mac_pipe_check_stat(active_cred, pipe->pipe_pair); - PIPE_UNLOCK(pipe); - if (error) + if (error) { + PIPE_UNLOCK(pipe); return (error); + } #endif + /* + * Lazily allocate an inode number for the pipe. Most pipe + * users do not call fstat(2) on the pipe, which means that + * postponing the inode allocation until it is must be + * returned to userland is useful. If alloc_unr failed, + * assign st_ino zero instead of returning an error. + * Special pipe_ino values: + * -1 - not yet initialized; + * 0 - alloc_unr failed, return 0 as st_ino forever. + */ + if (pipe->pipe_ino == (ino_t)-1) { + new_unr = alloc_unr(pipeino_unr); + if (new_unr != -1) + pipe->pipe_ino = new_unr; + else + pipe->pipe_ino = 0; + } + PIPE_UNLOCK(pipe); + bzero(ub, sizeof(*ub)); ub->st_mode = S_IFIFO; ub->st_blksize = PAGE_SIZE; |
