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/sys_rw.h"
31 #if !defined(HAVE_STRUCT_MSGHDR_MSG_CONTROL) && !defined(HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS)
32 # error Can not pass file descriptors
41 struct aio_fork_config
{
42 bool erratic_testing_mode
;
50 static int mmap_area_destructor(struct mmap_area
*area
)
52 munmap((void *)area
->ptr
, area
->size
);
56 static struct mmap_area
*mmap_area_init(TALLOC_CTX
*mem_ctx
, size_t size
)
58 struct mmap_area
*result
;
61 result
= talloc(mem_ctx
, struct mmap_area
);
63 DEBUG(0, ("talloc failed\n"));
67 fd
= open("/dev/zero", O_RDWR
);
69 DEBUG(3, ("open(\"/dev/zero\") failed: %s\n",
74 result
->ptr
= mmap(NULL
, size
, PROT_READ
|PROT_WRITE
,
75 MAP_SHARED
|MAP_FILE
, fd
, 0);
77 if (result
->ptr
== MAP_FAILED
) {
78 DEBUG(1, ("mmap failed: %s\n", strerror(errno
)));
83 talloc_set_destructor(result
, mmap_area_destructor
);
98 static const char *cmd_type_str(enum cmd_type cmd
)
113 result
= "<UNKNOWN>";
123 bool erratic_testing_mode
;
131 struct aio_child_list
;
134 struct aio_child
*prev
, *next
;
135 struct aio_child_list
*list
;
138 struct mmap_area
*map
;
139 bool dont_delete
; /* Marked as in use since last cleanup */
143 struct aio_child_list
{
144 struct aio_child
*children
;
145 struct tevent_timer
*cleanup_event
;
148 static void free_aio_children(void **p
)
153 static ssize_t
read_fd(int fd
, void *ptr
, size_t nbytes
, int *recvfd
)
158 #ifndef HAVE_STRUCT_MSGHDR_MSG_CONTROL
162 msg
.msg_accrights
= (caddr_t
) &newfd
;
163 msg
.msg_accrightslen
= sizeof(int);
168 char control
[CMSG_SPACE(sizeof(int))];
170 struct cmsghdr
*cmptr
;
173 ZERO_STRUCT(control_un
);
175 msg
.msg_control
= control_un
.control
;
176 msg
.msg_controllen
= sizeof(control_un
.control
);
182 iov
[0].iov_base
= (void *)ptr
;
183 iov
[0].iov_len
= nbytes
;
187 if ( (n
= recvmsg(fd
, &msg
, 0)) <= 0) {
191 #ifdef HAVE_STRUCT_MSGHDR_MSG_CONTROL
192 if ((cmptr
= CMSG_FIRSTHDR(&msg
)) != NULL
193 && cmptr
->cmsg_len
== CMSG_LEN(sizeof(int))) {
194 if (cmptr
->cmsg_level
!= SOL_SOCKET
) {
195 DEBUG(10, ("control level != SOL_SOCKET"));
199 if (cmptr
->cmsg_type
!= SCM_RIGHTS
) {
200 DEBUG(10, ("control type != SCM_RIGHTS"));
204 memcpy(recvfd
, CMSG_DATA(cmptr
), sizeof(*recvfd
));
206 *recvfd
= -1; /* descriptor was not passed */
209 if (msg
.msg_accrightslen
== sizeof(int)) {
213 *recvfd
= -1; /* descriptor was not passed */
220 static ssize_t
write_fd(int fd
, void *ptr
, size_t nbytes
, int sendfd
)
225 #ifdef HAVE_STRUCT_MSGHDR_MSG_CONTROL
228 char control
[CMSG_SPACE(sizeof(int))];
230 struct cmsghdr
*cmptr
;
233 ZERO_STRUCT(control_un
);
235 msg
.msg_control
= control_un
.control
;
236 msg
.msg_controllen
= sizeof(control_un
.control
);
238 cmptr
= CMSG_FIRSTHDR(&msg
);
239 cmptr
->cmsg_len
= CMSG_LEN(sizeof(int));
240 cmptr
->cmsg_level
= SOL_SOCKET
;
241 cmptr
->cmsg_type
= SCM_RIGHTS
;
242 memcpy(CMSG_DATA(cmptr
), &sendfd
, sizeof(sendfd
));
245 msg
.msg_accrights
= (caddr_t
) &sendfd
;
246 msg
.msg_accrightslen
= sizeof(int);
253 iov
[0].iov_base
= (void *)ptr
;
254 iov
[0].iov_len
= nbytes
;
258 return (sendmsg(fd
, &msg
, 0));
261 static void aio_child_cleanup(struct tevent_context
*event_ctx
,
262 struct tevent_timer
*te
,
266 struct aio_child_list
*list
= talloc_get_type_abort(
267 private_data
, struct aio_child_list
);
268 struct aio_child
*child
, *next
;
270 TALLOC_FREE(list
->cleanup_event
);
272 for (child
= list
->children
; child
!= NULL
; child
= next
) {
276 DEBUG(10, ("child %d currently active\n",
281 if (child
->dont_delete
) {
282 DEBUG(10, ("Child %d was active since last cleanup\n",
284 child
->dont_delete
= false;
288 DEBUG(10, ("Child %d idle for more than 30 seconds, "
289 "deleting\n", (int)child
->pid
));
295 if (list
->children
!= NULL
) {
297 * Re-schedule the next cleanup round
299 list
->cleanup_event
= tevent_add_timer(server_event_context(), list
,
300 timeval_add(&now
, 30, 0),
301 aio_child_cleanup
, list
);
306 static struct aio_child_list
*init_aio_children(struct vfs_handle_struct
*handle
)
308 struct aio_child_list
*data
= NULL
;
310 if (SMB_VFS_HANDLE_TEST_DATA(handle
)) {
311 SMB_VFS_HANDLE_GET_DATA(handle
, data
, struct aio_child_list
,
316 data
= talloc_zero(NULL
, struct aio_child_list
);
323 * Regardless of whether the child_list had been around or not, make
324 * sure that we have a cleanup timed event. This timed event will
325 * delete itself when it finds that no children are around anymore.
328 if (data
->cleanup_event
== NULL
) {
329 data
->cleanup_event
= tevent_add_timer(server_event_context(), data
,
330 timeval_current_ofs(30, 0),
331 aio_child_cleanup
, data
);
332 if (data
->cleanup_event
== NULL
) {
338 if (!SMB_VFS_HANDLE_TEST_DATA(handle
)) {
339 SMB_VFS_HANDLE_SET_DATA(handle
, data
, free_aio_children
,
340 struct aio_child_list
, return False
);
346 static void aio_child_loop(int sockfd
, struct mmap_area
*map
)
351 struct rw_cmd cmd_struct
;
352 struct rw_ret ret_struct
;
354 ret
= read_fd(sockfd
, &cmd_struct
, sizeof(cmd_struct
), &fd
);
355 if (ret
!= sizeof(cmd_struct
)) {
356 DEBUG(10, ("read_fd returned %d: %s\n", (int)ret
,
361 DEBUG(10, ("aio_child_loop: %s %d bytes at %d from fd %d\n",
362 cmd_type_str(cmd_struct
.cmd
),
363 (int)cmd_struct
.n
, (int)cmd_struct
.offset
, fd
));
365 if (cmd_struct
.erratic_testing_mode
) {
367 * For developer testing, we want erratic behaviour for
373 * use generate_random_buffer, we just forked from a
374 * common parent state
376 generate_random_buffer(&randval
, sizeof(randval
));
377 msecs
= randval
+ 20;
378 DEBUG(10, ("delaying for %u msecs\n", msecs
));
382 ZERO_STRUCT(ret_struct
);
384 switch (cmd_struct
.cmd
) {
386 ret_struct
.size
= sys_pread(
387 fd
, (void *)map
->ptr
, cmd_struct
.n
,
390 /* This breaks "make test" when run with aio_fork module. */
392 ret_struct
.size
= MAX(1, ret_struct
.size
* 0.9);
397 ret_struct
.size
= sys_pwrite(
398 fd
, (void *)map
->ptr
, cmd_struct
.n
,
402 ret_struct
.size
= fsync(fd
);
405 ret_struct
.size
= -1;
409 DEBUG(10, ("aio_child_loop: syscall returned %d\n",
410 (int)ret_struct
.size
));
412 if (ret_struct
.size
== -1) {
413 ret_struct
.ret_errno
= errno
;
417 * Close the fd before telling our parent we're done. The
418 * parent might close and re-open the file very quickly, and
419 * with system-level share modes (GPFS) we would get an
420 * unjustified SHARING_VIOLATION.
424 ret
= write_data(sockfd
, (char *)&ret_struct
,
426 if (ret
!= sizeof(ret_struct
)) {
427 DEBUG(10, ("could not write ret_struct: %s\n",
434 static int aio_child_destructor(struct aio_child
*child
)
438 SMB_ASSERT(!child
->busy
);
440 DEBUG(10, ("aio_child_destructor: removing child %d on fd %d\n",
441 child
->pid
, child
->sockfd
));
444 * closing the sockfd makes the child not return from recvmsg() on RHEL
445 * 5.5 so instead force the child to exit by writing bad data to it
447 write(child
->sockfd
, &c
, sizeof(c
));
448 close(child
->sockfd
);
449 DLIST_REMOVE(child
->list
->children
, child
);
454 * We have to close all fd's in open files, we might incorrectly hold a system
455 * level share mode on a file.
458 static struct files_struct
*close_fsp_fd(struct files_struct
*fsp
,
461 if ((fsp
->fh
!= NULL
) && (fsp
->fh
->fd
!= -1)) {
468 static int create_aio_child(struct smbd_server_connection
*sconn
,
469 struct aio_child_list
*children
,
471 struct aio_child
**presult
)
473 struct aio_child
*result
;
477 fdpair
[0] = fdpair
[1] = -1;
479 result
= talloc_zero(children
, struct aio_child
);
480 if (result
== NULL
) {
484 if (socketpair(AF_UNIX
, SOCK_STREAM
, 0, fdpair
) == -1) {
486 DEBUG(10, ("socketpair() failed: %s\n", strerror(errno
)));
490 DEBUG(10, ("fdpair = %d/%d\n", fdpair
[0], fdpair
[1]));
492 result
->map
= mmap_area_init(result
, map_size
);
493 if (result
->map
== NULL
) {
495 DEBUG(0, ("Could not create mmap area\n"));
499 result
->pid
= fork();
500 if (result
->pid
== -1) {
502 DEBUG(0, ("fork failed: %s\n", strerror(errno
)));
506 if (result
->pid
== 0) {
508 result
->sockfd
= fdpair
[1];
509 files_forall(sconn
, close_fsp_fd
, NULL
);
510 aio_child_loop(result
->sockfd
, result
->map
);
513 DEBUG(10, ("Child %d created with sockfd %d\n",
514 result
->pid
, fdpair
[0]));
516 result
->sockfd
= fdpair
[0];
519 result
->list
= children
;
520 DLIST_ADD(children
->children
, result
);
522 talloc_set_destructor(result
, aio_child_destructor
);
529 if (fdpair
[0] != -1) close(fdpair
[0]);
530 if (fdpair
[1] != -1) close(fdpair
[1]);
536 static int get_idle_child(struct vfs_handle_struct
*handle
,
537 struct aio_child
**pchild
)
539 struct aio_child_list
*children
;
540 struct aio_child
*child
;
542 children
= init_aio_children(handle
);
543 if (children
== NULL
) {
547 for (child
= children
->children
; child
!= NULL
; child
= child
->next
) {
556 DEBUG(10, ("no idle child found, creating new one\n"));
558 ret
= create_aio_child(handle
->conn
->sconn
, children
,
561 DEBUG(10, ("create_aio_child failed: %s\n",
567 child
->dont_delete
= true;
574 struct aio_fork_pread_state
{
575 struct aio_child
*child
;
580 static void aio_fork_pread_done(struct tevent_req
*subreq
);
582 static struct tevent_req
*aio_fork_pread_send(struct vfs_handle_struct
*handle
,
584 struct tevent_context
*ev
,
585 struct files_struct
*fsp
,
587 size_t n
, off_t offset
)
589 struct tevent_req
*req
, *subreq
;
590 struct aio_fork_pread_state
*state
;
594 struct aio_fork_config
*config
;
596 SMB_VFS_HANDLE_GET_DATA(handle
, config
,
597 struct aio_fork_config
,
600 req
= tevent_req_create(mem_ctx
, &state
, struct aio_fork_pread_state
);
606 /* TODO: support variable buffers */
607 tevent_req_error(req
, EINVAL
);
608 return tevent_req_post(req
, ev
);
611 err
= get_idle_child(handle
, &state
->child
);
613 tevent_req_error(req
, err
);
614 return tevent_req_post(req
, ev
);
621 cmd
.erratic_testing_mode
= config
->erratic_testing_mode
;
623 DEBUG(10, ("sending fd %d to child %d\n", fsp
->fh
->fd
,
624 (int)state
->child
->pid
));
627 * Not making this async. We're writing into an empty unix
628 * domain socket. This should never block.
630 written
= write_fd(state
->child
->sockfd
, &cmd
, sizeof(cmd
),
635 TALLOC_FREE(state
->child
);
637 DEBUG(10, ("write_fd failed: %s\n", strerror(err
)));
638 tevent_req_error(req
, err
);
639 return tevent_req_post(req
, ev
);
642 subreq
= read_packet_send(state
, ev
, state
->child
->sockfd
,
643 sizeof(struct rw_ret
), NULL
, NULL
);
644 if (tevent_req_nomem(subreq
, req
)) {
645 TALLOC_FREE(state
->child
); /* we sent sth down */
646 return tevent_req_post(req
, ev
);
648 tevent_req_set_callback(subreq
, aio_fork_pread_done
, req
);
652 static void aio_fork_pread_done(struct tevent_req
*subreq
)
654 struct tevent_req
*req
= tevent_req_callback_data(
655 subreq
, struct tevent_req
);
656 struct aio_fork_pread_state
*state
= tevent_req_data(
657 req
, struct aio_fork_pread_state
);
661 struct rw_ret
*retbuf
;
663 nread
= read_packet_recv(subreq
, talloc_tos(), &buf
, &err
);
666 TALLOC_FREE(state
->child
);
667 tevent_req_error(req
, err
);
671 state
->child
->busy
= false;
673 retbuf
= (struct rw_ret
*)buf
;
674 state
->ret
= retbuf
->size
;
675 state
->err
= retbuf
->ret_errno
;
676 tevent_req_done(req
);
679 static ssize_t
aio_fork_pread_recv(struct tevent_req
*req
, int *err
)
681 struct aio_fork_pread_state
*state
= tevent_req_data(
682 req
, struct aio_fork_pread_state
);
684 if (tevent_req_is_unix_error(req
, err
)) {
687 if (state
->ret
== -1) {
693 struct aio_fork_pwrite_state
{
694 struct aio_child
*child
;
699 static void aio_fork_pwrite_done(struct tevent_req
*subreq
);
701 static struct tevent_req
*aio_fork_pwrite_send(
702 struct vfs_handle_struct
*handle
, TALLOC_CTX
*mem_ctx
,
703 struct tevent_context
*ev
, struct files_struct
*fsp
,
704 const void *data
, size_t n
, off_t offset
)
706 struct tevent_req
*req
, *subreq
;
707 struct aio_fork_pwrite_state
*state
;
711 struct aio_fork_config
*config
;
712 SMB_VFS_HANDLE_GET_DATA(handle
, config
,
713 struct aio_fork_config
,
716 req
= tevent_req_create(mem_ctx
, &state
, struct aio_fork_pwrite_state
);
722 /* TODO: support variable buffers */
723 tevent_req_error(req
, EINVAL
);
724 return tevent_req_post(req
, ev
);
727 err
= get_idle_child(handle
, &state
->child
);
729 tevent_req_error(req
, err
);
730 return tevent_req_post(req
, ev
);
737 cmd
.erratic_testing_mode
= config
->erratic_testing_mode
;
739 DEBUG(10, ("sending fd %d to child %d\n", fsp
->fh
->fd
,
740 (int)state
->child
->pid
));
743 * Not making this async. We're writing into an empty unix
744 * domain socket. This should never block.
746 written
= write_fd(state
->child
->sockfd
, &cmd
, sizeof(cmd
),
751 TALLOC_FREE(state
->child
);
753 DEBUG(10, ("write_fd failed: %s\n", strerror(err
)));
754 tevent_req_error(req
, err
);
755 return tevent_req_post(req
, ev
);
758 subreq
= read_packet_send(state
, ev
, state
->child
->sockfd
,
759 sizeof(struct rw_ret
), NULL
, NULL
);
760 if (tevent_req_nomem(subreq
, req
)) {
761 TALLOC_FREE(state
->child
); /* we sent sth down */
762 return tevent_req_post(req
, ev
);
764 tevent_req_set_callback(subreq
, aio_fork_pwrite_done
, req
);
768 static void aio_fork_pwrite_done(struct tevent_req
*subreq
)
770 struct tevent_req
*req
= tevent_req_callback_data(
771 subreq
, struct tevent_req
);
772 struct aio_fork_pwrite_state
*state
= tevent_req_data(
773 req
, struct aio_fork_pwrite_state
);
777 struct rw_ret
*retbuf
;
779 nread
= read_packet_recv(subreq
, talloc_tos(), &buf
, &err
);
782 TALLOC_FREE(state
->child
);
783 tevent_req_error(req
, err
);
787 state
->child
->busy
= false;
789 retbuf
= (struct rw_ret
*)buf
;
790 state
->ret
= retbuf
->size
;
791 state
->err
= retbuf
->ret_errno
;
792 tevent_req_done(req
);
795 static ssize_t
aio_fork_pwrite_recv(struct tevent_req
*req
, int *err
)
797 struct aio_fork_pwrite_state
*state
= tevent_req_data(
798 req
, struct aio_fork_pwrite_state
);
800 if (tevent_req_is_unix_error(req
, err
)) {
803 if (state
->ret
== -1) {
809 struct aio_fork_fsync_state
{
810 struct aio_child
*child
;
815 static void aio_fork_fsync_done(struct tevent_req
*subreq
);
817 static struct tevent_req
*aio_fork_fsync_send(
818 struct vfs_handle_struct
*handle
, TALLOC_CTX
*mem_ctx
,
819 struct tevent_context
*ev
, struct files_struct
*fsp
)
821 struct tevent_req
*req
, *subreq
;
822 struct aio_fork_fsync_state
*state
;
826 struct aio_fork_config
*config
;
828 SMB_VFS_HANDLE_GET_DATA(handle
, config
,
829 struct aio_fork_config
,
832 req
= tevent_req_create(mem_ctx
, &state
, struct aio_fork_fsync_state
);
837 err
= get_idle_child(handle
, &state
->child
);
839 tevent_req_error(req
, err
);
840 return tevent_req_post(req
, ev
);
845 cmd
.erratic_testing_mode
= config
->erratic_testing_mode
;
847 DEBUG(10, ("sending fd %d to child %d\n", fsp
->fh
->fd
,
848 (int)state
->child
->pid
));
851 * Not making this async. We're writing into an empty unix
852 * domain socket. This should never block.
854 written
= write_fd(state
->child
->sockfd
, &cmd
, sizeof(cmd
),
859 TALLOC_FREE(state
->child
);
861 DEBUG(10, ("write_fd failed: %s\n", strerror(err
)));
862 tevent_req_error(req
, err
);
863 return tevent_req_post(req
, ev
);
866 subreq
= read_packet_send(state
, ev
, state
->child
->sockfd
,
867 sizeof(struct rw_ret
), NULL
, NULL
);
868 if (tevent_req_nomem(subreq
, req
)) {
869 TALLOC_FREE(state
->child
); /* we sent sth down */
870 return tevent_req_post(req
, ev
);
872 tevent_req_set_callback(subreq
, aio_fork_fsync_done
, req
);
876 static void aio_fork_fsync_done(struct tevent_req
*subreq
)
878 struct tevent_req
*req
= tevent_req_callback_data(
879 subreq
, struct tevent_req
);
880 struct aio_fork_fsync_state
*state
= tevent_req_data(
881 req
, struct aio_fork_fsync_state
);
885 struct rw_ret
*retbuf
;
887 nread
= read_packet_recv(subreq
, talloc_tos(), &buf
, &err
);
890 TALLOC_FREE(state
->child
);
891 tevent_req_error(req
, err
);
895 state
->child
->busy
= false;
897 retbuf
= (struct rw_ret
*)buf
;
898 state
->ret
= retbuf
->size
;
899 state
->err
= retbuf
->ret_errno
;
900 tevent_req_done(req
);
903 static int aio_fork_fsync_recv(struct tevent_req
*req
, int *err
)
905 struct aio_fork_fsync_state
*state
= tevent_req_data(
906 req
, struct aio_fork_fsync_state
);
908 if (tevent_req_is_unix_error(req
, err
)) {
911 if (state
->ret
== -1) {
917 static int aio_fork_connect(vfs_handle_struct
*handle
, const char *service
,
921 struct aio_fork_config
*config
;
922 ret
= SMB_VFS_NEXT_CONNECT(handle
, service
, user
);
928 config
= talloc_zero(handle
->conn
, struct aio_fork_config
);
930 SMB_VFS_NEXT_DISCONNECT(handle
);
931 DEBUG(0, ("talloc_zero() failed\n"));
935 config
->erratic_testing_mode
= lp_parm_bool(SNUM(handle
->conn
), "vfs_aio_fork",
936 "erratic_testing_mode", false);
938 SMB_VFS_HANDLE_SET_DATA(handle
, config
,
939 NULL
, struct aio_fork_config
,
942 /*********************************************************************
943 * How many threads to initialize ?
944 * 100 per process seems insane as a default until you realize that
945 * (a) Threads terminate after 1 second when idle.
946 * (b) Throttling is done in SMB2 via the crediting algorithm.
947 * (c) SMB1 clients are limited to max_mux (50) outstanding
948 * requests and Windows clients don't use this anyway.
949 * Essentially we want this to be unlimited unless smb.conf
951 *********************************************************************/
952 aio_pending_size
= 100;
956 static struct vfs_fn_pointers vfs_aio_fork_fns
= {
957 .connect_fn
= aio_fork_connect
,
958 .pread_send_fn
= aio_fork_pread_send
,
959 .pread_recv_fn
= aio_fork_pread_recv
,
960 .pwrite_send_fn
= aio_fork_pwrite_send
,
961 .pwrite_recv_fn
= aio_fork_pwrite_recv
,
962 .fsync_send_fn
= aio_fork_fsync_send
,
963 .fsync_recv_fn
= aio_fork_fsync_recv
,
966 NTSTATUS
vfs_aio_fork_init(void);
967 NTSTATUS
vfs_aio_fork_init(void)
969 return smb_register_vfs(SMB_VFS_INTERFACE_VERSION
,
970 "aio_fork", &vfs_aio_fork_fns
);