2 * Simulate the Posix AIO using mmap/fork
4 * Copyright (C) Volker Lendecke 2008
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
28 static int mmap_area_destructor(struct mmap_area
*area
)
30 munmap((void *)area
->ptr
, area
->size
);
34 static struct mmap_area
*mmap_area_init(TALLOC_CTX
*mem_ctx
, size_t size
)
36 struct mmap_area
*result
;
39 result
= talloc(mem_ctx
, struct mmap_area
);
41 DEBUG(0, ("talloc failed\n"));
45 fd
= open("/dev/zero", O_RDWR
);
47 DEBUG(3, ("open(\"/dev/zero\") failed: %s\n",
52 result
->ptr
= mmap(NULL
, size
, PROT_READ
|PROT_WRITE
,
53 MAP_SHARED
|MAP_FILE
, fd
, 0);
54 if (result
->ptr
== MAP_FAILED
) {
55 DEBUG(1, ("mmap failed: %s\n", strerror(errno
)));
62 talloc_set_destructor(result
, mmap_area_destructor
);
82 struct aio_child_list
;
85 struct aio_child
*prev
, *next
;
86 struct aio_child_list
*list
;
87 SMB_STRUCT_AIOCB
*aiocb
;
90 struct fd_event
*sock_event
;
92 struct mmap_area
*map
; /* ==NULL means write request */
93 bool dont_delete
; /* Marked as in use since last cleanup */
98 struct aio_child_list
{
99 struct aio_child
*children
;
100 struct timed_event
*cleanup_event
;
103 static void free_aio_children(void **p
)
108 static ssize_t
read_fd(int fd
, void *ptr
, size_t nbytes
, int *recvfd
)
113 #ifndef HAVE_MSGHDR_MSG_CONTROL
117 #ifdef HAVE_MSGHDR_MSG_CONTROL
120 char control
[CMSG_SPACE(sizeof(int))];
122 struct cmsghdr
*cmptr
;
124 msg
.msg_control
= control_un
.control
;
125 msg
.msg_controllen
= sizeof(control_un
.control
);
127 #if HAVE_MSGHDR_MSG_ACCTRIGHTS
128 msg
.msg_accrights
= (caddr_t
) &newfd
;
129 msg
.msg_accrightslen
= sizeof(int);
131 #error Can not pass file descriptors
138 iov
[0].iov_base
= (void *)ptr
;
139 iov
[0].iov_len
= nbytes
;
143 if ( (n
= recvmsg(fd
, &msg
, 0)) <= 0) {
147 #ifdef HAVE_MSGHDR_MSG_CONTROL
148 if ((cmptr
= CMSG_FIRSTHDR(&msg
)) != NULL
149 && cmptr
->cmsg_len
== CMSG_LEN(sizeof(int))) {
150 if (cmptr
->cmsg_level
!= SOL_SOCKET
) {
151 DEBUG(10, ("control level != SOL_SOCKET"));
155 if (cmptr
->cmsg_type
!= SCM_RIGHTS
) {
156 DEBUG(10, ("control type != SCM_RIGHTS"));
160 *recvfd
= *((int *) CMSG_DATA(cmptr
));
162 *recvfd
= -1; /* descriptor was not passed */
165 if (msg
.msg_accrightslen
== sizeof(int)) {
169 *recvfd
= -1; /* descriptor was not passed */
176 static ssize_t
write_fd(int fd
, void *ptr
, size_t nbytes
, int sendfd
)
181 #ifdef HAVE_MSGHDR_MSG_CONTROL
184 char control
[CMSG_SPACE(sizeof(int))];
186 struct cmsghdr
*cmptr
;
189 ZERO_STRUCT(control_un
);
191 msg
.msg_control
= control_un
.control
;
192 msg
.msg_controllen
= sizeof(control_un
.control
);
194 cmptr
= CMSG_FIRSTHDR(&msg
);
195 cmptr
->cmsg_len
= CMSG_LEN(sizeof(int));
196 cmptr
->cmsg_level
= SOL_SOCKET
;
197 cmptr
->cmsg_type
= SCM_RIGHTS
;
198 *((int *) CMSG_DATA(cmptr
)) = sendfd
;
201 msg
.msg_accrights
= (caddr_t
) &sendfd
;
202 msg
.msg_accrightslen
= sizeof(int);
209 iov
[0].iov_base
= (void *)ptr
;
210 iov
[0].iov_len
= nbytes
;
214 return (sendmsg(fd
, &msg
, 0));
217 static void aio_child_cleanup(struct event_context
*event_ctx
,
218 struct timed_event
*te
,
222 struct aio_child_list
*list
= talloc_get_type_abort(
223 private_data
, struct aio_child_list
);
224 struct aio_child
*child
, *next
;
226 TALLOC_FREE(list
->cleanup_event
);
228 for (child
= list
->children
; child
!= NULL
; child
= next
) {
231 if (child
->aiocb
!= NULL
) {
232 DEBUG(10, ("child %d currently active\n",
237 if (child
->dont_delete
) {
238 DEBUG(10, ("Child %d was active since last cleanup\n",
240 child
->dont_delete
= false;
244 DEBUG(10, ("Child %d idle for more than 30 seconds, "
245 "deleting\n", (int)child
->pid
));
250 if (list
->children
!= NULL
) {
252 * Re-schedule the next cleanup round
254 list
->cleanup_event
= event_add_timed(smbd_event_context(), list
,
255 timeval_add(&now
, 30, 0),
256 aio_child_cleanup
, list
);
261 static struct aio_child_list
*init_aio_children(struct vfs_handle_struct
*handle
)
263 struct aio_child_list
*data
= NULL
;
265 if (SMB_VFS_HANDLE_TEST_DATA(handle
)) {
266 SMB_VFS_HANDLE_GET_DATA(handle
, data
, struct aio_child_list
,
271 data
= TALLOC_ZERO_P(NULL
, struct aio_child_list
);
278 * Regardless of whether the child_list had been around or not, make
279 * sure that we have a cleanup timed event. This timed event will
280 * delete itself when it finds that no children are around anymore.
283 if (data
->cleanup_event
== NULL
) {
284 data
->cleanup_event
= event_add_timed(smbd_event_context(), data
,
285 timeval_current_ofs(30, 0),
286 aio_child_cleanup
, data
);
287 if (data
->cleanup_event
== NULL
) {
293 if (!SMB_VFS_HANDLE_TEST_DATA(handle
)) {
294 SMB_VFS_HANDLE_SET_DATA(handle
, data
, free_aio_children
,
295 struct aio_child_list
, return False
);
301 static void aio_child_loop(int sockfd
, struct mmap_area
*map
)
306 struct rw_cmd cmd_struct
;
307 struct rw_ret ret_struct
;
309 ret
= read_fd(sockfd
, &cmd_struct
, sizeof(cmd_struct
), &fd
);
310 if (ret
!= sizeof(cmd_struct
)) {
311 DEBUG(10, ("read_fd returned %d: %s\n", (int)ret
,
316 DEBUG(10, ("aio_child_loop: %s %d bytes at %d from fd %d\n",
317 cmd_struct
.read_cmd
? "read" : "write",
318 (int)cmd_struct
.n
, (int)cmd_struct
.offset
, fd
));
320 #ifdef ENABLE_BUILD_FARM_HACKS
323 * In the build farm, we want erratic behaviour for
329 * use generate_random_buffer, we just forked from a
330 * common parent state
332 generate_random_buffer(&randval
, sizeof(randval
));
333 msecs
= randval
+ 20;
334 DEBUG(10, ("delaying for %u msecs\n", msecs
));
340 ZERO_STRUCT(ret_struct
);
342 if (cmd_struct
.read_cmd
) {
343 ret_struct
.size
= sys_pread(
344 fd
, (void *)map
->ptr
, cmd_struct
.n
,
348 ret_struct
.size
= sys_pwrite(
349 fd
, (void *)map
->ptr
, cmd_struct
.n
,
353 DEBUG(10, ("aio_child_loop: syscall returned %d\n",
354 (int)ret_struct
.size
));
356 if (ret_struct
.size
== -1) {
357 ret_struct
.ret_errno
= errno
;
361 * Close the fd before telling our parent we're done. The
362 * parent might close and re-open the file very quickly, and
363 * with system-level share modes (GPFS) we would get an
364 * unjustified SHARING_VIOLATION.
368 ret
= write_data(sockfd
, (char *)&ret_struct
,
370 if (ret
!= sizeof(ret_struct
)) {
371 DEBUG(10, ("could not write ret_struct: %s\n",
378 static void handle_aio_completion(struct event_context
*event_ctx
,
379 struct fd_event
*event
, uint16 flags
,
382 struct aio_child
*child
= (struct aio_child
*)p
;
385 DEBUG(10, ("handle_aio_completion called with flags=%d\n", flags
));
387 if ((flags
& EVENT_FD_READ
) == 0) {
391 if (!NT_STATUS_IS_OK(read_data(child
->sockfd
,
392 (char *)&child
->retval
,
393 sizeof(child
->retval
)))) {
394 DEBUG(0, ("aio child %d died\n", (int)child
->pid
));
395 child
->retval
.size
= -1;
396 child
->retval
.ret_errno
= EIO
;
399 if (child
->cancelled
) {
401 child
->cancelled
= false;
405 if (child
->read_cmd
&& (child
->retval
.size
> 0)) {
406 SMB_ASSERT(child
->retval
.size
<= child
->aiocb
->aio_nbytes
);
407 memcpy((void *)child
->aiocb
->aio_buf
, (void *)child
->map
->ptr
,
411 mid
= child
->aiocb
->aio_sigevent
.sigev_value
.sival_int
;
413 DEBUG(10, ("mid %d finished\n", (int)mid
));
415 smbd_aio_complete_mid(mid
);
418 static int aio_child_destructor(struct aio_child
*child
)
420 SMB_ASSERT((child
->aiocb
== NULL
) || child
->cancelled
);
421 close(child
->sockfd
);
422 DLIST_REMOVE(child
->list
->children
, child
);
427 * We have to close all fd's in open files, we might incorrectly hold a system
428 * level share mode on a file.
431 static struct files_struct
*close_fsp_fd(struct files_struct
*fsp
,
434 if ((fsp
->fh
!= NULL
) && (fsp
->fh
->fd
!= -1)) {
441 static NTSTATUS
create_aio_child(struct aio_child_list
*children
,
443 struct aio_child
**presult
)
445 struct aio_child
*result
;
449 fdpair
[0] = fdpair
[1] = -1;
451 result
= TALLOC_ZERO_P(children
, struct aio_child
);
452 NT_STATUS_HAVE_NO_MEMORY(result
);
454 if (socketpair(AF_UNIX
, SOCK_STREAM
, 0, fdpair
) == -1) {
455 status
= map_nt_error_from_unix(errno
);
456 DEBUG(10, ("socketpair() failed: %s\n", strerror(errno
)));
460 DEBUG(10, ("fdpair = %d/%d\n", fdpair
[0], fdpair
[1]));
462 result
->map
= mmap_area_init(result
, map_size
);
463 if (result
->map
== NULL
) {
464 status
= map_nt_error_from_unix(errno
);
465 DEBUG(0, ("Could not create mmap area\n"));
469 result
->pid
= sys_fork();
470 if (result
->pid
== -1) {
471 status
= map_nt_error_from_unix(errno
);
472 DEBUG(0, ("fork failed: %s\n", strerror(errno
)));
476 if (result
->pid
== 0) {
478 result
->sockfd
= fdpair
[1];
479 file_walk_table(close_fsp_fd
, NULL
);
480 aio_child_loop(result
->sockfd
, result
->map
);
483 DEBUG(10, ("Child %d created\n", result
->pid
));
485 result
->sockfd
= fdpair
[0];
488 result
->sock_event
= event_add_fd(smbd_event_context(), result
,
489 result
->sockfd
, EVENT_FD_READ
,
490 handle_aio_completion
,
492 if (result
->sock_event
== NULL
) {
493 status
= NT_STATUS_NO_MEMORY
;
494 DEBUG(0, ("event_add_fd failed\n"));
498 result
->list
= children
;
499 DLIST_ADD(children
->children
, result
);
501 talloc_set_destructor(result
, aio_child_destructor
);
508 if (fdpair
[0] != -1) close(fdpair
[0]);
509 if (fdpair
[1] != -1) close(fdpair
[1]);
515 static NTSTATUS
get_idle_child(struct vfs_handle_struct
*handle
,
516 struct aio_child
**pchild
)
518 struct aio_child_list
*children
;
519 struct aio_child
*child
;
522 children
= init_aio_children(handle
);
523 if (children
== NULL
) {
524 return NT_STATUS_NO_MEMORY
;
527 for (child
= children
->children
; child
!= NULL
; child
= child
->next
) {
528 if (child
->aiocb
== NULL
) {
535 DEBUG(10, ("no idle child found, creating new one\n"));
537 status
= create_aio_child(children
, 128*1024, &child
);
538 if (!NT_STATUS_IS_OK(status
)) {
539 DEBUG(10, ("create_aio_child failed: %s\n",
545 child
->dont_delete
= true;
551 static int aio_fork_read(struct vfs_handle_struct
*handle
,
552 struct files_struct
*fsp
, SMB_STRUCT_AIOCB
*aiocb
)
554 struct aio_child
*child
;
559 if (aiocb
->aio_nbytes
> 128*1024) {
560 /* TODO: support variable buffers */
565 status
= get_idle_child(handle
, &child
);
566 if (!NT_STATUS_IS_OK(status
)) {
567 DEBUG(10, ("Could not get an idle child\n"));
571 child
->read_cmd
= true;
572 child
->aiocb
= aiocb
;
573 child
->retval
.ret_errno
= EINPROGRESS
;
576 cmd
.n
= aiocb
->aio_nbytes
;
577 cmd
.offset
= aiocb
->aio_offset
;
578 cmd
.read_cmd
= child
->read_cmd
;
580 DEBUG(10, ("sending fd %d to child %d\n", fsp
->fh
->fd
,
583 ret
= write_fd(child
->sockfd
, &cmd
, sizeof(cmd
), fsp
->fh
->fd
);
585 DEBUG(10, ("write_fd failed: %s\n", strerror(errno
)));
592 static int aio_fork_write(struct vfs_handle_struct
*handle
,
593 struct files_struct
*fsp
, SMB_STRUCT_AIOCB
*aiocb
)
595 struct aio_child
*child
;
600 if (aiocb
->aio_nbytes
> 128*1024) {
601 /* TODO: support variable buffers */
606 status
= get_idle_child(handle
, &child
);
607 if (!NT_STATUS_IS_OK(status
)) {
608 DEBUG(10, ("Could not get an idle child\n"));
612 child
->read_cmd
= false;
613 child
->aiocb
= aiocb
;
614 child
->retval
.ret_errno
= EINPROGRESS
;
616 memcpy((void *)child
->map
->ptr
, (void *)aiocb
->aio_buf
,
620 cmd
.n
= aiocb
->aio_nbytes
;
621 cmd
.offset
= aiocb
->aio_offset
;
622 cmd
.read_cmd
= child
->read_cmd
;
624 DEBUG(10, ("sending fd %d to child %d\n", fsp
->fh
->fd
,
627 ret
= write_fd(child
->sockfd
, &cmd
, sizeof(cmd
), fsp
->fh
->fd
);
629 DEBUG(10, ("write_fd failed: %s\n", strerror(errno
)));
636 static struct aio_child
*aio_fork_find_child(struct vfs_handle_struct
*handle
,
637 SMB_STRUCT_AIOCB
*aiocb
)
639 struct aio_child_list
*children
;
640 struct aio_child
*child
;
642 children
= init_aio_children(handle
);
643 if (children
== NULL
) {
647 for (child
= children
->children
; child
!= NULL
; child
= child
->next
) {
648 if (child
->aiocb
== aiocb
) {
656 static ssize_t
aio_fork_return_fn(struct vfs_handle_struct
*handle
,
657 struct files_struct
*fsp
,
658 SMB_STRUCT_AIOCB
*aiocb
)
660 struct aio_child
*child
= aio_fork_find_child(handle
, aiocb
);
664 DEBUG(0, ("returning EINVAL\n"));
670 if (child
->retval
.size
== -1) {
671 errno
= child
->retval
.ret_errno
;
674 return child
->retval
.size
;
677 static int aio_fork_cancel(struct vfs_handle_struct
*handle
,
678 struct files_struct
*fsp
,
679 SMB_STRUCT_AIOCB
*aiocb
)
681 struct aio_child_list
*children
;
682 struct aio_child
*child
;
684 children
= init_aio_children(handle
);
685 if (children
== NULL
) {
690 for (child
= children
->children
; child
!= NULL
; child
= child
->next
) {
691 if (child
->aiocb
== NULL
) {
694 if (child
->aiocb
->aio_fildes
!= fsp
->fh
->fd
) {
697 if ((aiocb
!= NULL
) && (child
->aiocb
!= aiocb
)) {
702 * We let the child do its job, but we discard the result when
706 child
->cancelled
= true;
712 static int aio_fork_error_fn(struct vfs_handle_struct
*handle
,
713 struct files_struct
*fsp
,
714 SMB_STRUCT_AIOCB
*aiocb
)
716 struct aio_child
*child
= aio_fork_find_child(handle
, aiocb
);
723 return child
->retval
.ret_errno
;
726 /* VFS operations structure */
728 static vfs_op_tuple aio_fork_ops
[] = {
729 {SMB_VFS_OP(aio_fork_read
), SMB_VFS_OP_AIO_READ
,
730 SMB_VFS_LAYER_TRANSPARENT
},
731 {SMB_VFS_OP(aio_fork_write
), SMB_VFS_OP_AIO_WRITE
,
732 SMB_VFS_LAYER_TRANSPARENT
},
733 {SMB_VFS_OP(aio_fork_return_fn
), SMB_VFS_OP_AIO_RETURN
,
734 SMB_VFS_LAYER_TRANSPARENT
},
735 {SMB_VFS_OP(aio_fork_cancel
), SMB_VFS_OP_AIO_CANCEL
,
736 SMB_VFS_LAYER_TRANSPARENT
},
737 {SMB_VFS_OP(aio_fork_error_fn
), SMB_VFS_OP_AIO_ERROR
,
738 SMB_VFS_LAYER_TRANSPARENT
},
739 {SMB_VFS_OP(NULL
), SMB_VFS_OP_NOOP
,
743 NTSTATUS
vfs_aio_fork_init(void);
744 NTSTATUS
vfs_aio_fork_init(void)
746 return smb_register_vfs(SMB_VFS_INTERFACE_VERSION
,
747 "aio_fork", aio_fork_ops
);