2 * Simulate the Posix AIO using mmap/fork
4 * Copyright (C) Volker Lendecke 2008
5 * Copyright (C) Jeremy Allison 2010
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 #include "system/filesys.h"
24 #include "system/shmem.h"
25 #include "smbd/smbd.h"
26 #include "smbd/globals.h"
27 #include "lib/async_req/async_sock.h"
28 #include "lib/util/tevent_unix.h"
29 #include "lib/util/sys_rw.h"
30 #include "lib/util/sys_rw_data.h"
31 #include "lib/util/msghdr.h"
32 #include "smbprofile.h"
34 #if !defined(HAVE_STRUCT_MSGHDR_MSG_CONTROL) && !defined(HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS)
35 # error Can not pass file descriptors
44 struct aio_child_list
;
46 struct aio_fork_config
{
47 bool erratic_testing_mode
;
48 struct aio_child_list
*children
;
56 static int mmap_area_destructor(struct mmap_area
*area
)
58 munmap(discard_const(area
->ptr
), area
->size
);
62 static struct mmap_area
*mmap_area_init(TALLOC_CTX
*mem_ctx
, size_t size
)
64 struct mmap_area
*result
;
67 result
= talloc(mem_ctx
, struct mmap_area
);
69 DEBUG(0, ("talloc failed\n"));
73 fd
= open("/dev/zero", O_RDWR
);
75 DEBUG(3, ("open(\"/dev/zero\") failed: %s\n",
80 result
->ptr
= mmap(NULL
, size
, PROT_READ
|PROT_WRITE
,
81 MAP_SHARED
|MAP_FILE
, fd
, 0);
83 if (result
->ptr
== MAP_FAILED
) {
84 DEBUG(1, ("mmap failed: %s\n", strerror(errno
)));
89 talloc_set_destructor(result
, mmap_area_destructor
);
104 static const char *cmd_type_str(enum cmd_type cmd
)
119 result
= "<UNKNOWN>";
129 bool erratic_testing_mode
;
138 struct aio_child_list
;
141 struct aio_child
*prev
, *next
;
142 struct aio_child_list
*list
;
145 struct mmap_area
*map
;
146 bool dont_delete
; /* Marked as in use since last cleanup */
150 struct aio_child_list
{
151 struct aio_child
*children
;
152 struct tevent_timer
*cleanup_event
;
155 static ssize_t
read_fd(int fd
, void *ptr
, size_t nbytes
, int *recvfd
)
158 struct msghdr msg
= { .msg_iov
= iov
, .msg_iovlen
= 1 };
160 size_t bufsize
= msghdr_prep_recv_fds(NULL
, NULL
, 0, 1);
161 uint8_t buf
[bufsize
];
163 msghdr_prep_recv_fds(&msg
, buf
, bufsize
, 1);
165 iov
[0].iov_base
= (void *)ptr
;
166 iov
[0].iov_len
= nbytes
;
169 n
= recvmsg(fd
, &msg
, 0);
170 } while ((n
== -1) && (errno
== EINTR
));
177 size_t num_fds
= msghdr_extract_fds(&msg
, NULL
, 0);
180 msghdr_extract_fds(&msg
, fds
, num_fds
);
185 for (i
=0; i
<num_fds
; i
++) {
199 static ssize_t
write_fd(int fd
, void *ptr
, size_t nbytes
, int sendfd
)
201 struct msghdr msg
= {0};
202 size_t bufsize
= msghdr_prep_fds(NULL
, NULL
, 0, &sendfd
, 1);
203 uint8_t buf
[bufsize
];
207 msghdr_prep_fds(&msg
, buf
, bufsize
, &sendfd
, 1);
209 iov
.iov_base
= (void *)ptr
;
210 iov
.iov_len
= nbytes
;
215 sent
= sendmsg(fd
, &msg
, 0);
216 } while ((sent
== -1) && (errno
== EINTR
));
221 static void aio_child_cleanup(struct tevent_context
*event_ctx
,
222 struct tevent_timer
*te
,
226 struct aio_child_list
*list
= talloc_get_type_abort(
227 private_data
, struct aio_child_list
);
228 struct aio_child
*child
, *next
;
230 TALLOC_FREE(list
->cleanup_event
);
232 for (child
= list
->children
; child
!= NULL
; child
= next
) {
236 DEBUG(10, ("child %d currently active\n",
241 if (child
->dont_delete
) {
242 DEBUG(10, ("Child %d was active since last cleanup\n",
244 child
->dont_delete
= false;
248 DEBUG(10, ("Child %d idle for more than 30 seconds, "
249 "deleting\n", (int)child
->pid
));
255 if (list
->children
!= NULL
) {
257 * Re-schedule the next cleanup round
259 list
->cleanup_event
= tevent_add_timer(server_event_context(), list
,
260 timeval_add(&now
, 30, 0),
261 aio_child_cleanup
, list
);
266 static struct aio_child_list
*init_aio_children(struct vfs_handle_struct
*handle
)
268 struct aio_fork_config
*config
;
269 struct aio_child_list
*children
;
271 SMB_VFS_HANDLE_GET_DATA(handle
, config
, struct aio_fork_config
,
274 if (config
->children
== NULL
) {
275 config
->children
= talloc_zero(config
, struct aio_child_list
);
276 if (config
->children
== NULL
) {
280 children
= config
->children
;
283 * Regardless of whether the child_list had been around or not, make
284 * sure that we have a cleanup timed event. This timed event will
285 * delete itself when it finds that no children are around anymore.
288 if (children
->cleanup_event
== NULL
) {
289 children
->cleanup_event
=
290 tevent_add_timer(server_event_context(), children
,
291 timeval_current_ofs(30, 0),
292 aio_child_cleanup
, children
);
293 if (children
->cleanup_event
== NULL
) {
294 TALLOC_FREE(config
->children
);
302 static void aio_child_loop(int sockfd
, struct mmap_area
*map
)
307 struct rw_cmd cmd_struct
;
308 struct rw_ret ret_struct
;
309 struct timespec start
, end
;
311 ret
= read_fd(sockfd
, &cmd_struct
, sizeof(cmd_struct
), &fd
);
312 if (ret
!= sizeof(cmd_struct
)) {
313 DEBUG(10, ("read_fd returned %d: %s\n", (int)ret
,
318 DEBUG(10, ("aio_child_loop: %s %d bytes at %d from fd %d\n",
319 cmd_type_str(cmd_struct
.cmd
),
320 (int)cmd_struct
.n
, (int)cmd_struct
.offset
, fd
));
322 if (cmd_struct
.erratic_testing_mode
) {
324 * For developer testing, we want erratic behaviour for
330 * use generate_random_buffer, we just forked from a
331 * common parent state
333 generate_random_buffer(&randval
, sizeof(randval
));
334 msecs
= (randval
%20)+1;
335 DEBUG(10, ("delaying for %u msecs\n", msecs
));
339 ZERO_STRUCT(ret_struct
);
341 PROFILE_TIMESTAMP(&start
);
343 switch (cmd_struct
.cmd
) {
345 ret_struct
.size
= sys_pread(
346 fd
, discard_const(map
->ptr
), cmd_struct
.n
,
349 /* This breaks "make test" when run with aio_fork module. */
351 ret_struct
.size
= MAX(1, ret_struct
.size
* 0.9);
356 ret_struct
.size
= sys_pwrite(
357 fd
, discard_const(map
->ptr
), cmd_struct
.n
,
361 ret_struct
.size
= fsync(fd
);
364 ret_struct
.size
= -1;
368 PROFILE_TIMESTAMP(&end
);
369 ret_struct
.duration
= nsec_time_diff(&end
, &start
);
370 DEBUG(10, ("aio_child_loop: syscall returned %d\n",
371 (int)ret_struct
.size
));
373 if (ret_struct
.size
== -1) {
374 ret_struct
.ret_errno
= errno
;
378 * Close the fd before telling our parent we're done. The
379 * parent might close and re-open the file very quickly, and
380 * with system-level share modes (GPFS) we would get an
381 * unjustified SHARING_VIOLATION.
385 ret
= write_data(sockfd
, (char *)&ret_struct
,
387 if (ret
!= sizeof(ret_struct
)) {
388 DEBUG(10, ("could not write ret_struct: %s\n",
395 static int aio_child_destructor(struct aio_child
*child
)
399 SMB_ASSERT(!child
->busy
);
401 DEBUG(10, ("aio_child_destructor: removing child %d on fd %d\n",
402 (int)child
->pid
, child
->sockfd
));
405 * closing the sockfd makes the child not return from recvmsg() on RHEL
406 * 5.5 so instead force the child to exit by writing bad data to it
408 sys_write_v(child
->sockfd
, &c
, sizeof(c
));
409 close(child
->sockfd
);
410 DLIST_REMOVE(child
->list
->children
, child
);
415 * We have to close all fd's in open files, we might incorrectly hold a system
416 * level share mode on a file.
419 static struct files_struct
*close_fsp_fd(struct files_struct
*fsp
,
422 if ((fsp
->fh
!= NULL
) && (fsp
->fh
->fd
!= -1)) {
429 static int create_aio_child(struct smbd_server_connection
*sconn
,
430 struct aio_child_list
*children
,
432 struct aio_child
**presult
)
434 struct aio_child
*result
;
438 fdpair
[0] = fdpair
[1] = -1;
440 result
= talloc_zero(children
, struct aio_child
);
441 if (result
== NULL
) {
445 if (socketpair(AF_UNIX
, SOCK_STREAM
, 0, fdpair
) == -1) {
447 DEBUG(10, ("socketpair() failed: %s\n", strerror(errno
)));
451 DEBUG(10, ("fdpair = %d/%d\n", fdpair
[0], fdpair
[1]));
453 result
->map
= mmap_area_init(result
, map_size
);
454 if (result
->map
== NULL
) {
456 DEBUG(0, ("Could not create mmap area\n"));
460 result
->pid
= fork();
461 if (result
->pid
== -1) {
463 DEBUG(0, ("fork failed: %s\n", strerror(errno
)));
467 if (result
->pid
== 0) {
469 result
->sockfd
= fdpair
[1];
470 files_forall(sconn
, close_fsp_fd
, NULL
);
471 aio_child_loop(result
->sockfd
, result
->map
);
474 DEBUG(10, ("Child %d created with sockfd %d\n",
475 (int)result
->pid
, fdpair
[0]));
477 result
->sockfd
= fdpair
[0];
480 result
->list
= children
;
481 DLIST_ADD(children
->children
, result
);
483 talloc_set_destructor(result
, aio_child_destructor
);
490 if (fdpair
[0] != -1) close(fdpair
[0]);
491 if (fdpair
[1] != -1) close(fdpair
[1]);
497 static int get_idle_child(struct vfs_handle_struct
*handle
,
498 struct aio_child
**pchild
)
500 struct aio_child_list
*children
;
501 struct aio_child
*child
;
503 children
= init_aio_children(handle
);
504 if (children
== NULL
) {
508 for (child
= children
->children
; child
!= NULL
; child
= child
->next
) {
517 DEBUG(10, ("no idle child found, creating new one\n"));
519 ret
= create_aio_child(handle
->conn
->sconn
, children
,
522 DEBUG(10, ("create_aio_child failed: %s\n",
528 child
->dont_delete
= true;
535 struct aio_fork_pread_state
{
536 struct aio_child
*child
;
540 struct vfs_aio_state vfs_aio_state
;
543 static void aio_fork_pread_done(struct tevent_req
*subreq
);
545 static struct tevent_req
*aio_fork_pread_send(struct vfs_handle_struct
*handle
,
547 struct tevent_context
*ev
,
548 struct files_struct
*fsp
,
550 size_t n
, off_t offset
)
552 struct tevent_req
*req
, *subreq
;
553 struct aio_fork_pread_state
*state
;
557 struct aio_fork_config
*config
;
559 SMB_VFS_HANDLE_GET_DATA(handle
, config
,
560 struct aio_fork_config
,
563 req
= tevent_req_create(mem_ctx
, &state
, struct aio_fork_pread_state
);
571 /* TODO: support variable buffers */
572 tevent_req_error(req
, EINVAL
);
573 return tevent_req_post(req
, ev
);
576 err
= get_idle_child(handle
, &state
->child
);
578 tevent_req_error(req
, err
);
579 return tevent_req_post(req
, ev
);
586 cmd
.erratic_testing_mode
= config
->erratic_testing_mode
;
588 DEBUG(10, ("sending fd %d to child %d\n", fsp
->fh
->fd
,
589 (int)state
->child
->pid
));
592 * Not making this async. We're writing into an empty unix
593 * domain socket. This should never block.
595 written
= write_fd(state
->child
->sockfd
, &cmd
, sizeof(cmd
),
600 TALLOC_FREE(state
->child
);
602 DEBUG(10, ("write_fd failed: %s\n", strerror(err
)));
603 tevent_req_error(req
, err
);
604 return tevent_req_post(req
, ev
);
607 subreq
= read_packet_send(state
, ev
, state
->child
->sockfd
,
608 sizeof(struct rw_ret
), NULL
, NULL
);
609 if (tevent_req_nomem(subreq
, req
)) {
610 TALLOC_FREE(state
->child
); /* we sent sth down */
611 return tevent_req_post(req
, ev
);
613 tevent_req_set_callback(subreq
, aio_fork_pread_done
, req
);
617 static void aio_fork_pread_done(struct tevent_req
*subreq
)
619 struct tevent_req
*req
= tevent_req_callback_data(
620 subreq
, struct tevent_req
);
621 struct aio_fork_pread_state
*state
= tevent_req_data(
622 req
, struct aio_fork_pread_state
);
626 struct rw_ret
*retbuf
;
628 nread
= read_packet_recv(subreq
, talloc_tos(), &buf
, &err
);
631 TALLOC_FREE(state
->child
);
632 tevent_req_error(req
, err
);
636 retbuf
= (struct rw_ret
*)buf
;
637 state
->ret
= retbuf
->size
;
638 state
->vfs_aio_state
.error
= retbuf
->ret_errno
;
639 state
->vfs_aio_state
.duration
= retbuf
->duration
;
641 if ((size_t)state
->ret
> state
->n
) {
642 tevent_req_error(req
, EIO
);
643 state
->child
->busy
= false;
646 memcpy(state
->data
, state
->child
->map
->ptr
, state
->ret
);
648 state
->child
->busy
= false;
650 tevent_req_done(req
);
653 static ssize_t
aio_fork_pread_recv(struct tevent_req
*req
,
654 struct vfs_aio_state
*vfs_aio_state
)
656 struct aio_fork_pread_state
*state
= tevent_req_data(
657 req
, struct aio_fork_pread_state
);
659 if (tevent_req_is_unix_error(req
, &vfs_aio_state
->error
)) {
662 *vfs_aio_state
= state
->vfs_aio_state
;
666 struct aio_fork_pwrite_state
{
667 struct aio_child
*child
;
669 struct vfs_aio_state vfs_aio_state
;
672 static void aio_fork_pwrite_done(struct tevent_req
*subreq
);
674 static struct tevent_req
*aio_fork_pwrite_send(
675 struct vfs_handle_struct
*handle
, TALLOC_CTX
*mem_ctx
,
676 struct tevent_context
*ev
, struct files_struct
*fsp
,
677 const void *data
, size_t n
, off_t offset
)
679 struct tevent_req
*req
, *subreq
;
680 struct aio_fork_pwrite_state
*state
;
684 struct aio_fork_config
*config
;
685 SMB_VFS_HANDLE_GET_DATA(handle
, config
,
686 struct aio_fork_config
,
689 req
= tevent_req_create(mem_ctx
, &state
, struct aio_fork_pwrite_state
);
695 /* TODO: support variable buffers */
696 tevent_req_error(req
, EINVAL
);
697 return tevent_req_post(req
, ev
);
700 err
= get_idle_child(handle
, &state
->child
);
702 tevent_req_error(req
, err
);
703 return tevent_req_post(req
, ev
);
706 memcpy(state
->child
->map
->ptr
, data
, n
);
712 cmd
.erratic_testing_mode
= config
->erratic_testing_mode
;
714 DEBUG(10, ("sending fd %d to child %d\n", fsp
->fh
->fd
,
715 (int)state
->child
->pid
));
718 * Not making this async. We're writing into an empty unix
719 * domain socket. This should never block.
721 written
= write_fd(state
->child
->sockfd
, &cmd
, sizeof(cmd
),
726 TALLOC_FREE(state
->child
);
728 DEBUG(10, ("write_fd failed: %s\n", strerror(err
)));
729 tevent_req_error(req
, err
);
730 return tevent_req_post(req
, ev
);
733 subreq
= read_packet_send(state
, ev
, state
->child
->sockfd
,
734 sizeof(struct rw_ret
), NULL
, NULL
);
735 if (tevent_req_nomem(subreq
, req
)) {
736 TALLOC_FREE(state
->child
); /* we sent sth down */
737 return tevent_req_post(req
, ev
);
739 tevent_req_set_callback(subreq
, aio_fork_pwrite_done
, req
);
743 static void aio_fork_pwrite_done(struct tevent_req
*subreq
)
745 struct tevent_req
*req
= tevent_req_callback_data(
746 subreq
, struct tevent_req
);
747 struct aio_fork_pwrite_state
*state
= tevent_req_data(
748 req
, struct aio_fork_pwrite_state
);
752 struct rw_ret
*retbuf
;
754 nread
= read_packet_recv(subreq
, talloc_tos(), &buf
, &err
);
757 TALLOC_FREE(state
->child
);
758 tevent_req_error(req
, err
);
762 state
->child
->busy
= false;
764 retbuf
= (struct rw_ret
*)buf
;
765 state
->ret
= retbuf
->size
;
766 state
->vfs_aio_state
.error
= retbuf
->ret_errno
;
767 state
->vfs_aio_state
.duration
= retbuf
->duration
;
768 tevent_req_done(req
);
771 static ssize_t
aio_fork_pwrite_recv(struct tevent_req
*req
,
772 struct vfs_aio_state
*vfs_aio_state
)
774 struct aio_fork_pwrite_state
*state
= tevent_req_data(
775 req
, struct aio_fork_pwrite_state
);
777 if (tevent_req_is_unix_error(req
, &vfs_aio_state
->error
)) {
780 *vfs_aio_state
= state
->vfs_aio_state
;
784 struct aio_fork_fsync_state
{
785 struct aio_child
*child
;
787 struct vfs_aio_state vfs_aio_state
;
790 static void aio_fork_fsync_done(struct tevent_req
*subreq
);
792 static struct tevent_req
*aio_fork_fsync_send(
793 struct vfs_handle_struct
*handle
, TALLOC_CTX
*mem_ctx
,
794 struct tevent_context
*ev
, struct files_struct
*fsp
)
796 struct tevent_req
*req
, *subreq
;
797 struct aio_fork_fsync_state
*state
;
801 struct aio_fork_config
*config
;
803 SMB_VFS_HANDLE_GET_DATA(handle
, config
,
804 struct aio_fork_config
,
807 req
= tevent_req_create(mem_ctx
, &state
, struct aio_fork_fsync_state
);
812 err
= get_idle_child(handle
, &state
->child
);
814 tevent_req_error(req
, err
);
815 return tevent_req_post(req
, ev
);
820 cmd
.erratic_testing_mode
= config
->erratic_testing_mode
;
822 DEBUG(10, ("sending fd %d to child %d\n", fsp
->fh
->fd
,
823 (int)state
->child
->pid
));
826 * Not making this async. We're writing into an empty unix
827 * domain socket. This should never block.
829 written
= write_fd(state
->child
->sockfd
, &cmd
, sizeof(cmd
),
834 TALLOC_FREE(state
->child
);
836 DEBUG(10, ("write_fd failed: %s\n", strerror(err
)));
837 tevent_req_error(req
, err
);
838 return tevent_req_post(req
, ev
);
841 subreq
= read_packet_send(state
, ev
, state
->child
->sockfd
,
842 sizeof(struct rw_ret
), NULL
, NULL
);
843 if (tevent_req_nomem(subreq
, req
)) {
844 TALLOC_FREE(state
->child
); /* we sent sth down */
845 return tevent_req_post(req
, ev
);
847 tevent_req_set_callback(subreq
, aio_fork_fsync_done
, req
);
851 static void aio_fork_fsync_done(struct tevent_req
*subreq
)
853 struct tevent_req
*req
= tevent_req_callback_data(
854 subreq
, struct tevent_req
);
855 struct aio_fork_fsync_state
*state
= tevent_req_data(
856 req
, struct aio_fork_fsync_state
);
860 struct rw_ret
*retbuf
;
862 nread
= read_packet_recv(subreq
, talloc_tos(), &buf
, &err
);
865 TALLOC_FREE(state
->child
);
866 tevent_req_error(req
, err
);
870 state
->child
->busy
= false;
872 retbuf
= (struct rw_ret
*)buf
;
873 state
->ret
= retbuf
->size
;
874 state
->vfs_aio_state
.error
= retbuf
->ret_errno
;
875 state
->vfs_aio_state
.duration
= retbuf
->duration
;
876 tevent_req_done(req
);
879 static int aio_fork_fsync_recv(struct tevent_req
*req
,
880 struct vfs_aio_state
*vfs_aio_state
)
882 struct aio_fork_fsync_state
*state
= tevent_req_data(
883 req
, struct aio_fork_fsync_state
);
885 if (tevent_req_is_unix_error(req
, &vfs_aio_state
->error
)) {
888 *vfs_aio_state
= state
->vfs_aio_state
;
892 static int aio_fork_connect(vfs_handle_struct
*handle
, const char *service
,
896 struct aio_fork_config
*config
;
897 ret
= SMB_VFS_NEXT_CONNECT(handle
, service
, user
);
903 config
= talloc_zero(handle
->conn
, struct aio_fork_config
);
905 SMB_VFS_NEXT_DISCONNECT(handle
);
906 DEBUG(0, ("talloc_zero() failed\n"));
910 config
->erratic_testing_mode
= lp_parm_bool(SNUM(handle
->conn
), "vfs_aio_fork",
911 "erratic_testing_mode", false);
913 SMB_VFS_HANDLE_SET_DATA(handle
, config
,
914 NULL
, struct aio_fork_config
,
920 static struct vfs_fn_pointers vfs_aio_fork_fns
= {
921 .connect_fn
= aio_fork_connect
,
922 .pread_send_fn
= aio_fork_pread_send
,
923 .pread_recv_fn
= aio_fork_pread_recv
,
924 .pwrite_send_fn
= aio_fork_pwrite_send
,
925 .pwrite_recv_fn
= aio_fork_pwrite_recv
,
926 .fsync_send_fn
= aio_fork_fsync_send
,
927 .fsync_recv_fn
= aio_fork_fsync_recv
,
931 NTSTATUS
vfs_aio_fork_init(TALLOC_CTX
*ctx
)
933 return smb_register_vfs(SMB_VFS_INTERFACE_VERSION
,
934 "aio_fork", &vfs_aio_fork_fns
);