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authorGregor Beck <gbeck@sernet.de>2013-02-07 15:26:37 +0100
committerMichael Adam <obnox@samba.org>2013-04-18 13:15:13 +0200
commit1ed22ba4b7998c1fc29476e931bd463f2bc1ba7e (patch)
tree0a148ac55120c72a786a8c71cdf1f04d403e38a1 /source3/smbd/scavenger.c
parentf608bedfca4118b7e3606802df40e266bcc099d8 (diff)
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s3:smbd: add a scavenger process for disconnected durable handles
Pair-Programmed-With: Stefan Metzmacher <metze@samba.org> Signed-off-by: Gregor Beck <gbeck@sernet.de> Signed-off-by: Stefan Metzmacher <metze@samba.org> Reviewed-by: Michael Adam <obnox@samba.org>
Diffstat (limited to 'source3/smbd/scavenger.c')
-rw-r--r--source3/smbd/scavenger.c531
1 files changed, 531 insertions, 0 deletions
diff --git a/source3/smbd/scavenger.c b/source3/smbd/scavenger.c
new file mode 100644
index 0000000000..fe4e56e613
--- /dev/null
+++ b/source3/smbd/scavenger.c
@@ -0,0 +1,531 @@
+/*
+ Unix SMB/CIFS implementation.
+ smbd scavenger daemon
+
+ Copyright (C) Gregor Beck 2013
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+
+#include "messages.h"
+#include "serverid.h"
+#include "smbd/globals.h"
+#include "smbd/scavenger.h"
+#include "locking/proto.h"
+#include "lib/util/util_process.h"
+
+#undef DBGC_CLASS
+#define DBGC_CLASS DBGC_SCAVENGER
+
+struct smbd_scavenger_state {
+ struct tevent_context *ev;
+ struct messaging_context *msg;
+ struct server_id parent_id;
+ struct server_id *scavenger_id;
+ bool am_scavenger;
+};
+
+static struct smbd_scavenger_state *smbd_scavenger_state = NULL;
+
+struct scavenger_message {
+ struct file_id file_id;
+ uint64_t open_persistent_id;
+ NTTIME until;
+};
+
+static int smbd_scavenger_main(struct smbd_scavenger_state *state)
+{
+ DEBUG(10, ("scavenger: %s started, parent: %s\n",
+ server_id_str(talloc_tos(), state->scavenger_id),
+ server_id_str(talloc_tos(), &state->parent_id)));
+
+ while (true) {
+ TALLOC_CTX *frame = talloc_stackframe();
+ int ret;
+
+ ret = tevent_loop_once(state->ev);
+ if (ret != 0) {
+ DEBUG(2, ("tevent_loop_once failed: %s\n",
+ strerror(errno)));
+ TALLOC_FREE(frame);
+ return 1;
+ }
+
+ DEBUG(10, ("scavenger: %s event loop iteration\n",
+ server_id_str(talloc_tos(), state->scavenger_id)));
+ TALLOC_FREE(frame);
+ }
+
+ return 0;
+}
+
+static void smbd_scavenger_done(struct tevent_context *event_ctx, struct tevent_fd *fde,
+ uint16_t flags, void *private_data)
+{
+ struct smbd_scavenger_state *state = talloc_get_type_abort(
+ private_data, struct smbd_scavenger_state);
+
+ DEBUG(2, ("scavenger: %s died\n",
+ server_id_str(talloc_tos(), state->scavenger_id)));
+
+ TALLOC_FREE(state->scavenger_id);
+}
+
+static void smbd_scavenger_parent_dead(struct tevent_context *event_ctx,
+ struct tevent_fd *fde,
+ uint16_t flags, void *private_data)
+{
+ struct smbd_scavenger_state *state = talloc_get_type_abort(
+ private_data, struct smbd_scavenger_state);
+
+ DEBUG(2, ("scavenger: %s parent %s died\n",
+ server_id_str(talloc_tos(), state->scavenger_id),
+ server_id_str(talloc_tos(), &state->parent_id)));
+
+ exit_server("smbd_scavenger_parent_dead");
+}
+
+static void scavenger_sig_term_handler(struct tevent_context *ev,
+ struct tevent_signal *se,
+ int signum,
+ int count,
+ void *siginfo,
+ void *private_data)
+{
+ exit_server_cleanly("termination signal");
+}
+
+static void scavenger_setup_sig_term_handler(struct tevent_context *ev_ctx)
+{
+ struct tevent_signal *se;
+
+ se = tevent_add_signal(ev_ctx,
+ ev_ctx,
+ SIGTERM, 0,
+ scavenger_sig_term_handler,
+ NULL);
+ if (se == NULL) {
+ exit_server("failed to setup SIGTERM handler");
+ }
+}
+
+static bool smbd_scavenger_running(struct smbd_scavenger_state *state)
+{
+ if (state->scavenger_id == NULL) {
+ return false;
+ }
+
+ return serverid_exists(state->scavenger_id);
+}
+
+static int smbd_scavenger_server_id_destructor(struct server_id *id)
+{
+ serverid_deregister(*id);
+ return 0;
+}
+
+static bool scavenger_say_hello(int fd, struct server_id self)
+{
+ const uint8_t *msg = (const uint8_t *)&self;
+ size_t remaining = sizeof(self);
+ size_t ofs = 0;
+
+ while (remaining > 0) {
+ ssize_t ret;
+
+ ret = sys_write(fd, msg + ofs, remaining);
+ if (ret == -1) {
+ DEBUG(2, ("Failed to write to pipe: %s\n",
+ strerror(errno)));
+ return false;
+ }
+ remaining -= ret;
+ }
+
+ DEBUG(4, ("scavenger_say_hello: self[%s]\n",
+ server_id_str(talloc_tos(), &self)));
+ return true;
+}
+
+static bool scavenger_wait_hello(int fd, struct server_id *child)
+{
+ uint8_t *msg = (uint8_t *)child;
+ size_t remaining = sizeof(*child);
+ size_t ofs = 0;
+
+ while (remaining > 0) {
+ ssize_t ret;
+
+ ret = sys_read(fd, msg + ofs, remaining);
+ if (ret == -1) {
+ DEBUG(2, ("Failed to read from pipe: %s\n",
+ strerror(errno)));
+ return false;
+ }
+ remaining -= ret;
+ }
+
+ DEBUG(4, ("scavenger_say_hello: child[%s]\n",
+ server_id_str(talloc_tos(), child)));
+ return true;
+}
+
+static bool smbd_scavenger_start(struct smbd_scavenger_state *state)
+{
+ struct server_id self = messaging_server_id(state->msg);
+ struct tevent_fd *fde = NULL;
+ int fds[2];
+ int ret;
+ uint64_t unique_id;
+ bool ok;
+
+ SMB_ASSERT(server_id_equal(&state->parent_id, &self));
+
+ if (smbd_scavenger_running(state)) {
+ DEBUG(10, ("scavenger %s already running\n",
+ server_id_str(talloc_tos(),
+ state->scavenger_id)));
+ return true;
+ }
+
+ if (state->scavenger_id != NULL) {
+ DEBUG(10, ("scavenger zombie %s, cleaning up\n",
+ server_id_str(talloc_tos(),
+ state->scavenger_id)));
+ TALLOC_FREE(state->scavenger_id);
+ }
+
+ state->scavenger_id = talloc_zero(state, struct server_id);
+ if (state->scavenger_id == NULL) {
+ DEBUG(2, ("Out of memory\n"));
+ goto fail;
+ }
+ talloc_set_destructor(state->scavenger_id,
+ smbd_scavenger_server_id_destructor);
+
+ ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fds);
+ if (ret == -1) {
+ DEBUG(2, ("socketpair failed: %s", strerror(errno)));
+ goto fail;
+ }
+
+ smb_set_close_on_exec(fds[0]);
+ smb_set_close_on_exec(fds[1]);
+
+ unique_id = serverid_get_random_unique_id();
+
+ ret = fork();
+ if (ret == -1) {
+ int err = errno;
+ close(fds[0]);
+ close(fds[1]);
+ DEBUG(0, ("fork failed: %s", strerror(err)));
+ goto fail;
+ }
+
+ if (ret == 0) {
+ /* child */
+
+ NTSTATUS status;
+
+ close(fds[0]);
+
+ am_parent = NULL;
+
+ set_my_unique_id(unique_id);
+
+ status = reinit_after_fork(state->msg, state->ev, true);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(2, ("reinit_after_fork failed: %s\n",
+ nt_errstr(status)));
+ exit_server("reinit_after_fork failed");
+ return false;
+ }
+
+ prctl_set_comment("smbd-scavenger");
+
+ state->am_scavenger = true;
+ *state->scavenger_id = messaging_server_id(state->msg);
+
+ scavenger_setup_sig_term_handler(state->ev);
+
+ serverid_register(*state->scavenger_id, FLAG_MSG_GENERAL);
+
+ ok = scavenger_say_hello(fds[1], *state->scavenger_id);
+ if (!ok) {
+ DEBUG(2, ("scavenger_say_hello failed\n"));
+ exit_server("scavenger_say_hello failed");
+ return false;
+ }
+
+ fde = tevent_add_fd(state->ev, state->scavenger_id,
+ fds[1], TEVENT_FD_READ,
+ smbd_scavenger_parent_dead, state);
+ if (fde == NULL) {
+ DEBUG(2, ("tevent_add_fd(smbd_scavenger_parent_dead) "
+ "failed\n"));
+ exit_server("tevent_add_fd(smbd_scavenger_parent_dead) "
+ "failed");
+ return false;
+ }
+ tevent_fd_set_auto_close(fde);
+
+ ret = smbd_scavenger_main(state);
+
+ DEBUG(10, ("scavenger ended: %d\n", ret));
+ exit_server_cleanly("scavenger ended");
+ return false;
+ }
+
+ /* parent */
+ close(fds[1]);
+
+ ok = scavenger_wait_hello(fds[0], state->scavenger_id);
+ if (!ok) {
+ close(fds[0]);
+ goto fail;
+ }
+
+ fde = tevent_add_fd(state->ev, state->scavenger_id,
+ fds[0], TEVENT_FD_READ,
+ smbd_scavenger_done, state);
+ if (fde == NULL) {
+ close(fds[0]);
+ goto fail;
+ }
+ tevent_fd_set_auto_close(fde);
+
+ return true;
+fail:
+ TALLOC_FREE(state->scavenger_id);
+ return false;
+}
+
+static void scavenger_add_timer(struct smbd_scavenger_state *state,
+ struct scavenger_message *msg);
+
+static void smbd_scavenger_msg(struct messaging_context *msg_ctx,
+ void *private_data,
+ uint32_t msg_type,
+ struct server_id src,
+ DATA_BLOB *data)
+{
+ struct smbd_scavenger_state *state =
+ talloc_get_type_abort(private_data,
+ struct smbd_scavenger_state);
+ TALLOC_CTX *frame = talloc_stackframe();
+ struct server_id self = messaging_server_id(msg_ctx);
+ struct scavenger_message *msg = NULL;
+
+ DEBUG(10, ("smbd_scavenger_msg: %s got message from %s\n",
+ server_id_str(talloc_tos(), &self),
+ server_id_str(talloc_tos(), &src)));
+
+ if (server_id_equal(&state->parent_id, &self)) {
+ NTSTATUS status;
+
+ if (!smbd_scavenger_running(state) &&
+ !smbd_scavenger_start(state))
+ {
+ DEBUG(2, ("Failed to start scavenger\n"));
+ goto done;
+ }
+ DEBUG(10, ("forwarding message to scavenger\n"));
+
+ status = messaging_send(msg_ctx,
+ *state->scavenger_id, msg_type, data);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(2, ("forwarding message to scavenger failed: "
+ "%s\n", nt_errstr(status)));
+ goto done;
+ }
+ goto done;
+ }
+
+ if (!state->am_scavenger) {
+ DEBUG(10, ("im not the scavenger: ignore message\n"));
+ goto done;
+ }
+
+ if (!server_id_equal(&state->parent_id, &src)) {
+ DEBUG(10, ("scavenger: ignore spurious message\n"));
+ goto done;
+ }
+
+ DEBUG(10, ("scavenger: got a message\n"));
+ msg = (struct scavenger_message*)data->data;
+ scavenger_add_timer(state, msg);
+done:
+ talloc_free(frame);
+}
+
+bool smbd_scavenger_init(TALLOC_CTX *mem_ctx,
+ struct messaging_context *msg,
+ struct tevent_context *ev)
+{
+ struct smbd_scavenger_state *state;
+ NTSTATUS status;
+
+ if (smbd_scavenger_state) {
+ DEBUG(10, ("smbd_scavenger_init called again\n"));
+ return true;
+ }
+
+ state = talloc_zero(mem_ctx, struct smbd_scavenger_state);
+ if (state == NULL) {
+ DEBUG(2, ("Out of memory\n"));
+ return false;
+ }
+
+ state->msg = msg;
+ state->ev = ev;
+ state->parent_id = messaging_server_id(msg);
+
+ status = messaging_register(msg, state, MSG_SMB_SCAVENGER,
+ smbd_scavenger_msg);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(2, ("failed to register message handler: %s\n",
+ nt_errstr(status)));
+ goto fail;
+ }
+
+ smbd_scavenger_state = state;
+ return true;
+fail:
+ talloc_free(state);
+ return false;
+}
+
+void scavenger_schedule_disconnected(struct files_struct *fsp)
+{
+ NTSTATUS status;
+ struct server_id self = messaging_server_id(fsp->conn->sconn->msg_ctx);
+ struct timeval disconnect_time, until;
+ uint64_t timeout_usec;
+ struct scavenger_message msg;
+ DATA_BLOB msg_blob;
+
+ nttime_to_timeval(&disconnect_time, fsp->op->global->disconnect_time);
+ timeout_usec = 1000 * fsp->op->global->durable_timeout_msec;
+ until = timeval_add(&disconnect_time,
+ timeout_usec / 1000000,
+ timeout_usec % 1000000);
+
+ ZERO_STRUCT(msg);
+ msg.file_id = fsp->file_id;
+ msg.open_persistent_id = fsp->op->global->open_persistent_id;
+ msg.until = timeval_to_nttime(&until);
+
+ DEBUG(10, ("smbd: %s mark file %s as disconnected at %s with timeout "
+ "at %s in %fs\n",
+ server_id_str(talloc_tos(), &self),
+ file_id_string_tos(&fsp->file_id),
+ timeval_string(talloc_tos(), &disconnect_time, true),
+ timeval_string(talloc_tos(), &until, true),
+ fsp->op->global->durable_timeout_msec/1000.0));
+
+ SMB_ASSERT(server_id_is_disconnected(&fsp->op->global->server_id));
+ SMB_ASSERT(!server_id_equal(&self, &smbd_scavenger_state->parent_id));
+ SMB_ASSERT(!smbd_scavenger_state->am_scavenger);
+
+ msg_blob = data_blob_const(&msg, sizeof(msg));
+ DEBUG(10, ("send message to scavenger\n"));
+
+ status = messaging_send(smbd_scavenger_state->msg,
+ smbd_scavenger_state->parent_id,
+ MSG_SMB_SCAVENGER,
+ &msg_blob);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(2, ("Failed to send message to parent smbd %s "
+ "from %s: %s\n",
+ server_id_str(talloc_tos(),
+ &smbd_scavenger_state->parent_id),
+ server_id_str(talloc_tos(), &self),
+ nt_errstr(status)));
+ }
+}
+
+struct scavenger_timer_context {
+ struct smbd_scavenger_state *state;
+ struct scavenger_message msg;
+};
+
+static void scavenger_timer(struct tevent_context *ev,
+ struct tevent_timer *te,
+ struct timeval t, void *data)
+{
+ struct scavenger_timer_context *ctx =
+ talloc_get_type_abort(data, struct scavenger_timer_context);
+ NTSTATUS status;
+ bool ok;
+
+ DEBUG(10, ("scavenger: do cleanup for file %s at %s\n",
+ file_id_string_tos(&ctx->msg.file_id),
+ timeval_string(talloc_tos(), &t, true)));
+
+ ok = share_mode_cleanup_disconnected(ctx->msg.file_id,
+ ctx->msg.open_persistent_id);
+ if (!ok) {
+ DEBUG(2, ("Failed to cleanup share modes and byte range locks "
+ "for file %s open %lu\n",
+ file_id_string_tos(&ctx->msg.file_id),
+ ctx->msg.open_persistent_id));
+ }
+
+ status = smbXsrv_open_cleanup(ctx->msg.open_persistent_id);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(2, ("Failed to cleanup open global for file %s open %lu:"
+ " %s\n", file_id_string_tos(&ctx->msg.file_id),
+ ctx->msg.open_persistent_id, nt_errstr(status)));
+ }
+}
+
+static void scavenger_add_timer(struct smbd_scavenger_state *state,
+ struct scavenger_message *msg)
+{
+ struct tevent_timer *te;
+ struct scavenger_timer_context *ctx;
+ struct timeval until;
+
+ nttime_to_timeval(&until, msg->until);
+
+ DEBUG(10, ("scavenger: schedule file %s for cleanup at %s\n",
+ file_id_string_tos(&msg->file_id),
+ timeval_string(talloc_tos(), &until, true)));
+
+ ctx = talloc_zero(state, struct scavenger_timer_context);
+ if (ctx == NULL) {
+ DEBUG(2, ("Failed to talloc_zero(scavenger_timer_context)\n"));
+ return;
+ }
+
+ ctx->state = state;
+ ctx->msg = *msg;
+
+ te = tevent_add_timer(state->ev,
+ state,
+ until,
+ scavenger_timer,
+ ctx);
+ if (te == NULL) {
+ DEBUG(2, ("Failed to add scavenger_timer event\n"));
+ talloc_free(ctx);
+ return;
+ }
+
+ /* delete context after handler was running */
+ talloc_steal(te, ctx);
+}