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Illumos #3740 

3740 Poor ZFS send / receive performance due to snapshot
     hold / release processing
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Christopher Siden <christopher.siden@delphix.com>

References:
  https://www.illumos.org/issues/3740
  illumos/illumos-gate@a7a845e4bf

Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1775

Porting notes:

1. 13fe019870 introduced a merge conflict
   in dsl_dataset_user_release_tmp where some variables were moved
   outside of the preprocessor directive.

2. dea9dfefdd747534b3846845629d2200f0616dad made the previous merge
   conflict worse by switching KM_SLEEP to KM_PUSHPAGE. This is notable
   because this commit refactors the code, adding a new KM_SLEEP
   allocation. It is not clear to me whether this should be converted
   to KM_PUSHPAGE.

3. We had a merge conflict in libzfs_sendrecv.c because of copyright
   notices.

4. Several small C99 compatibility fixed were made.
This commit is contained in:
Steven Hartland 2013-05-25 02:06:23 +00:00 committed by Brian Behlendorf
parent 7bc7f25040
commit 95fd54a1c5
13 changed files with 672 additions and 505 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
cmd/zfs/zfs_main.c
View File

@ -24,6 +24,7 @@
* Copyright 2012 Nexenta Systems, Inc. All rights reserved.
* Copyright (c) 2012 by Delphix. All rights reserved.
* Copyright (c) 2012, Joyent, Inc. All rights reserved.
* Copyright (c) 2013 Steven Hartland. All rights reserved.
*/
#include <assert.h>
@ -5193,8 +5194,7 @@ zfs_do_hold_rele_impl(int argc, char **argv, boolean_t holding)
continue;
}
if (holding) {
if (zfs_hold(zhp, delim+1, tag, recursive,
B_FALSE, -1) != 0)
if (zfs_hold(zhp, delim+1, tag, recursive, -1) != 0)
++errors;
} else {
if (zfs_release(zhp, delim+1, tag, recursive) != 0)

3
cmd/zhack/zhack.c
View File

@ -21,6 +21,7 @@
/*
* Copyright (c) 2012 by Delphix. All rights reserved.
* Copyright (c) 2013 Steven Hartland. All rights reserved.
*/
/*
@ -152,7 +153,7 @@ import_pool(const char *target, boolean_t readonly)
g_importargs.poolname = g_pool;
pools = zpool_search_import(g_zfs, &g_importargs);
if (pools == NULL || nvlist_next_nvpair(pools, NULL) == NULL) {
if (nvlist_empty(pools)) {
if (!g_importargs.can_be_active) {
g_importargs.can_be_active = B_TRUE;
if (zpool_search_import(g_zfs, &g_importargs) != NULL ||

3
cmd/ztest/ztest.c
View File

@ -22,6 +22,7 @@
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2012 by Delphix. All rights reserved.
* Copyright 2011 Nexenta Systems, Inc. All rights reserved.
* Copyright (c) 2013 Steven Hartland. All rights reserved.
*/
/*
@ -4830,7 +4831,7 @@ ztest_dmu_snapshot_hold(ztest_ds_t *zd, uint64_t id)
error = user_release_one(fullname, tag);
if (error)
fatal(0, "user_release_one(%s)", fullname, tag);
fatal(0, "user_release_one(%s, %s) = %d", fullname, tag, error);
VERIFY3U(dmu_objset_hold(fullname, FTAG, &origin), ==, ENOENT);

4
include/libzfs.h
View File

@ -24,6 +24,7 @@
* Copyright 2011 Nexenta Systems, Inc. All rights reserved.
* Copyright (c) 2012 by Delphix. All rights reserved.
* Copyright (c) 2012, Joyent, Inc. All rights reserved.
* Copyright (c) 2013 Steven Hartland. All rights reserved.
*/
#ifndef _LIBZFS_H
@ -614,7 +615,8 @@ extern int zfs_send(zfs_handle_t *, const char *, const char *,
extern int zfs_promote(zfs_handle_t *);
extern int zfs_hold(zfs_handle_t *, const char *, const char *,
boolean_t, boolean_t, int);
boolean_t, int);
extern int zfs_hold_nvl(zfs_handle_t *, int, nvlist_t *);
extern int zfs_release(zfs_handle_t *, const char *, const char *, boolean_t);
extern int zfs_get_holds(zfs_handle_t *, nvlist_t **);
extern uint64_t zvol_volsize_to_reservation(uint64_t, nvlist_t *);

3
include/sys/dsl_dataset.h
View File

@ -22,6 +22,7 @@
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2012 by Delphix. All rights reserved.
* Copyright (c) 2012, Joyent, Inc. All rights reserved.
* Copyright (c) 2013 Steven Hartland. All rights reserved.
*/
#ifndef _SYS_DSL_DATASET_H
@ -187,8 +188,6 @@ int dsl_dataset_own_obj(struct dsl_pool *dp, uint64_t dsobj,
void dsl_dataset_disown(dsl_dataset_t *ds, void *tag);
void dsl_dataset_name(dsl_dataset_t *ds, char *name);
boolean_t dsl_dataset_tryown(dsl_dataset_t *ds, void *tag);
void dsl_register_onexit_hold_cleanup(dsl_dataset_t *ds, const char *htag,
minor_t minor);
uint64_t dsl_dataset_create_sync(dsl_dir_t *pds, const char *lastname,
dsl_dataset_t *origin, uint64_t flags, cred_t *, dmu_tx_t *);
uint64_t dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin,

4
include/sys/dsl_userhold.h
View File

@ -23,6 +23,7 @@
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2012 by Delphix. All rights reserved.
* Copyright (c) 2012, Joyent, Inc. All rights reserved.
* Copyright (c) 2013 Steven Hartland. All rights reserved.
*/
#ifndef _SYS_DSL_USERHOLD_H
@ -43,8 +44,7 @@ int dsl_dataset_user_hold(nvlist_t *holds, minor_t cleanup_minor,
nvlist_t *errlist);
int dsl_dataset_user_release(nvlist_t *holds, nvlist_t *errlist);
int dsl_dataset_get_holds(const char *dsname, nvlist_t *nvl);
void dsl_dataset_user_release_tmp(struct dsl_pool *dp, uint64_t dsobj,
const char *htag);
void dsl_dataset_user_release_tmp(struct dsl_pool *dp, nvlist_t *holds);
int dsl_dataset_user_hold_check_one(struct dsl_dataset *ds, const char *htag,
boolean_t temphold, struct dmu_tx *tx);
void dsl_dataset_user_hold_sync_one(struct dsl_dataset *ds, const char *htag,

85
lib/libzfs/libzfs_dataset.c
View File

@ -26,6 +26,7 @@
* Copyright (c) 2012 Pawel Jakub Dawidek <pawel@dawidek.net>.
* Copyright 2012 Nexenta Systems, Inc. All rights reserved.
* Copyright (c) 2013 Martin Matuska. All rights reserved.
* Copyright (c) 2013 Steven Hartland. All rights reserved.
*/
#include <ctype.h>
@ -3153,18 +3154,14 @@ static int
zfs_check_snap_cb(zfs_handle_t *zhp, void *arg)
{
struct destroydata *dd = arg;
zfs_handle_t *szhp;
char name[ZFS_MAXNAMELEN];
int rv = 0;
(void) snprintf(name, sizeof (name),
"%s@%s", zhp->zfs_name, dd->snapname);
szhp = make_dataset_handle(zhp->zfs_hdl, name);
if (szhp) {
if (lzc_exists(name))
verify(nvlist_add_boolean(dd->nvl, name) == 0);
zfs_close(szhp);
}
if (zhp->zfs_type == ZFS_TYPE_VOLUME) {
(void) zvol_remove_link(zhp->zfs_hdl, name);
@ -3193,7 +3190,7 @@ zfs_destroy_snaps(zfs_handle_t *zhp, char *snapname, boolean_t defer)
verify(nvlist_alloc(&dd.nvl, NV_UNIQUE_NAME, 0) == 0);
(void) zfs_check_snap_cb(zfs_handle_dup(zhp), &dd);
if (nvlist_next_nvpair(dd.nvl, NULL) == NULL) {
if (nvlist_empty(dd.nvl)) {
ret = zfs_standard_error_fmt(zhp->zfs_hdl, ENOENT,
dgettext(TEXT_DOMAIN, "cannot destroy '%s@%s'"),
zhp->zfs_name, snapname);
@ -3219,7 +3216,7 @@ zfs_destroy_snaps_nvl(libzfs_handle_t *hdl, nvlist_t *snaps, boolean_t defer)
if (ret == 0)
return (0);
if (nvlist_next_nvpair(errlist, NULL) == NULL) {
if (nvlist_empty(errlist)) {
char errbuf[1024];
(void) snprintf(errbuf, sizeof (errbuf),
dgettext(TEXT_DOMAIN, "cannot destroy snapshots"));
@ -4421,18 +4418,14 @@ static int
zfs_hold_one(zfs_handle_t *zhp, void *arg)
{
struct holdarg *ha = arg;
zfs_handle_t *szhp;
char name[ZFS_MAXNAMELEN];
int rv = 0;
(void) snprintf(name, sizeof (name),
"%s@%s", zhp->zfs_name, ha->snapname);
szhp = make_dataset_handle(zhp->zfs_hdl, name);
if (szhp) {
if (lzc_exists(name))
fnvlist_add_string(ha->nvl, name, ha->tag);
zfs_close(szhp);
}
if (ha->recursive)
rv = zfs_iter_filesystems(zhp, zfs_hold_one, ha);
@ -4442,14 +4435,10 @@ zfs_hold_one(zfs_handle_t *zhp, void *arg)
int
zfs_hold(zfs_handle_t *zhp, const char *snapname, const char *tag,
boolean_t recursive, boolean_t enoent_ok, int cleanup_fd)
boolean_t recursive, int cleanup_fd)
{
int ret;
struct holdarg ha;
nvlist_t *errors;
libzfs_handle_t *hdl = zhp->zfs_hdl;
char errbuf[1024];
nvpair_t *elem;
ha.nvl = fnvlist_alloc();
ha.snapname = snapname;
@ -4457,26 +4446,44 @@ zfs_hold(zfs_handle_t *zhp, const char *snapname, const char *tag,
ha.recursive = recursive;
(void) zfs_hold_one(zfs_handle_dup(zhp), &ha);
if (nvlist_next_nvpair(ha.nvl, NULL) == NULL) {
if (nvlist_empty(ha.nvl)) {
char errbuf[1024];
fnvlist_free(ha.nvl);
ret = ENOENT;
if (!enoent_ok) {
(void) snprintf(errbuf, sizeof (errbuf),
dgettext(TEXT_DOMAIN,
"cannot hold snapshot '%s@%s'"),
zhp->zfs_name, snapname);
(void) zfs_standard_error(hdl, ret, errbuf);
}
(void) zfs_standard_error(zhp->zfs_hdl, ret, errbuf);
return (ret);
}
ret = lzc_hold(ha.nvl, cleanup_fd, &errors);
ret = zfs_hold_nvl(zhp, cleanup_fd, ha.nvl);
fnvlist_free(ha.nvl);
if (ret == 0)
return (0);
return (ret);
}
if (nvlist_next_nvpair(errors, NULL) == NULL) {
int
zfs_hold_nvl(zfs_handle_t *zhp, int cleanup_fd, nvlist_t *holds)
{
int ret;
nvlist_t *errors;
libzfs_handle_t *hdl = zhp->zfs_hdl;
char errbuf[1024];
nvpair_t *elem;
errors = NULL;
ret = lzc_hold(holds, cleanup_fd, &errors);
if (ret == 0) {
/* There may be errors even in the success case. */
fnvlist_free(errors);
return (0);
}
if (nvlist_empty(errors)) {
/* no hold-specific errors */
(void) snprintf(errbuf, sizeof (errbuf),
dgettext(TEXT_DOMAIN, "cannot hold"));
@ -4516,10 +4523,6 @@ zfs_hold(zfs_handle_t *zhp, const char *snapname, const char *tag,
case EEXIST:
(void) zfs_error(hdl, EZFS_REFTAG_HOLD, errbuf);
break;
case ENOENT:
if (enoent_ok)
return (ENOENT);
/* FALLTHROUGH */
default:
(void) zfs_standard_error(hdl,
fnvpair_value_int32(elem), errbuf);
@ -4530,30 +4533,21 @@ zfs_hold(zfs_handle_t *zhp, const char *snapname, const char *tag,
return (ret);
}
struct releasearg {
nvlist_t *nvl;
const char *snapname;
const char *tag;
boolean_t recursive;
};
static int
zfs_release_one(zfs_handle_t *zhp, void *arg)
{
struct holdarg *ha = arg;
zfs_handle_t *szhp;
char name[ZFS_MAXNAMELEN];
int rv = 0;
(void) snprintf(name, sizeof (name),
"%s@%s", zhp->zfs_name, ha->snapname);
szhp = make_dataset_handle(zhp->zfs_hdl, name);
if (szhp) {
if (lzc_exists(name)) {
nvlist_t *holds = fnvlist_alloc();
fnvlist_add_boolean(holds, ha->tag);
fnvlist_add_nvlist(ha->nvl, name, holds);
zfs_close(szhp);
fnvlist_free(holds);
}
if (ha->recursive)
@ -4568,7 +4562,7 @@ zfs_release(zfs_handle_t *zhp, const char *snapname, const char *tag,
{
int ret;
struct holdarg ha;
nvlist_t *errors;
nvlist_t *errors = NULL;
nvpair_t *elem;
libzfs_handle_t *hdl = zhp->zfs_hdl;
char errbuf[1024];
@ -4579,7 +4573,7 @@ zfs_release(zfs_handle_t *zhp, const char *snapname, const char *tag,
ha.recursive = recursive;
(void) zfs_release_one(zfs_handle_dup(zhp), &ha);
if (nvlist_next_nvpair(ha.nvl, NULL) == NULL) {
if (nvlist_empty(ha.nvl)) {
fnvlist_free(ha.nvl);
ret = ENOENT;
(void) snprintf(errbuf, sizeof (errbuf),
@ -4593,10 +4587,13 @@ zfs_release(zfs_handle_t *zhp, const char *snapname, const char *tag,
ret = lzc_release(ha.nvl, &errors);
fnvlist_free(ha.nvl);
if (ret == 0)
if (ret == 0) {
/* There may be errors even in the success case. */
fnvlist_free(errors);
return (0);
}
if (nvlist_next_nvpair(errors, NULL) == NULL) {
if (nvlist_empty(errors)) {
/* no hold-specific errors */
(void) snprintf(errbuf, sizeof (errbuf), dgettext(TEXT_DOMAIN,
"cannot release"));

128
lib/libzfs/libzfs_sendrecv.c
View File

@ -22,9 +22,10 @@
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2012 by Delphix. All rights reserved.
* Copyright (c) 2012 Pawel Jakub Dawidek <pawel@dawidek.net>.
* Copyright (c) 2012, Joyent, Inc. All rights reserved.
* Copyright (c) 2012 Pawel Jakub Dawidek <pawel@dawidek.net>.
* All rights reserved
* Copyright (c) 2013 Steven Hartland. All rights reserved.
*/
#include <assert.h>
@ -799,6 +800,7 @@ typedef struct send_dump_data {
int outfd;
boolean_t err;
nvlist_t *fss;
nvlist_t *snapholds;
avl_tree_t *fsavl;
snapfilter_cb_t *filter_cb;
void *filter_cb_arg;
@ -948,41 +950,19 @@ dump_ioctl(zfs_handle_t *zhp, const char *fromsnap, uint64_t fromsnap_obj,
return (0);
}
static int
hold_for_send(zfs_handle_t *zhp, send_dump_data_t *sdd)
static void
gather_holds(zfs_handle_t *zhp, send_dump_data_t *sdd)
{
zfs_handle_t *pzhp;
int error = 0;
char *thissnap;
assert(zhp->zfs_type == ZFS_TYPE_SNAPSHOT);
if (sdd->dryrun)
return (0);
/*
* zfs_send() only opens a cleanup_fd for sends that need it,
* zfs_send() only sets snapholds for sends that need them,
* e.g. replication and doall.
*/
if (sdd->cleanup_fd == -1)
return (0);
if (sdd->snapholds == NULL)
return;
thissnap = strchr(zhp->zfs_name, '@') + 1;
*(thissnap - 1) = '\0';
pzhp = zfs_open(zhp->zfs_hdl, zhp->zfs_name, ZFS_TYPE_DATASET);
*(thissnap - 1) = '@';
/*
* It's OK if the parent no longer exists. The send code will
* handle that error.
*/
if (pzhp) {
error = zfs_hold(pzhp, thissnap, sdd->holdtag,
B_FALSE, B_TRUE, sdd->cleanup_fd);
zfs_close(pzhp);
}
return (error);
fnvlist_add_string(sdd->snapholds, zhp->zfs_name, sdd->holdtag);
}
static void *
@ -1038,28 +1018,23 @@ dump_snapshot(zfs_handle_t *zhp, void *arg)
send_dump_data_t *sdd = arg;
progress_arg_t pa = { 0 };
pthread_t tid;
char *thissnap;
int err;
boolean_t isfromsnap, istosnap, fromorigin;
boolean_t exclude = B_FALSE;
err = 0;
thissnap = strchr(zhp->zfs_name, '@') + 1;
isfromsnap = (sdd->fromsnap != NULL &&
strcmp(sdd->fromsnap, thissnap) == 0);
if (!sdd->seenfrom && isfromsnap) {
err = hold_for_send(zhp, sdd);
if (err == 0) {
gather_holds(zhp, sdd);
sdd->seenfrom = B_TRUE;
(void) strcpy(sdd->prevsnap, thissnap);
sdd->prevsnap_obj = zfs_prop_get_int(zhp,
ZFS_PROP_OBJSETID);
} else if (err == ENOENT) {
err = 0;
}
sdd->prevsnap_obj = zfs_prop_get_int(zhp, ZFS_PROP_OBJSETID);
zfs_close(zhp);
return (err);
return (0);
}
if (sdd->seento || !sdd->seenfrom) {
@ -1110,14 +1085,7 @@ dump_snapshot(zfs_handle_t *zhp, void *arg)
return (0);
}
err = hold_for_send(zhp, sdd);
if (err) {
if (err == ENOENT)
err = 0;
zfs_close(zhp);
return (err);
}
gather_holds(zhp, sdd);
fromorigin = sdd->prevsnap[0] == '\0' &&
(sdd->fromorigin || sdd->replicate);
@ -1385,7 +1353,7 @@ zfs_send(zfs_handle_t *zhp, const char *fromsnap, const char *tosnap,
avl_tree_t *fsavl = NULL;
static uint64_t holdseq;
int spa_version;
pthread_t tid;
pthread_t tid = 0;
int pipefd[2];
dedup_arg_t dda = { 0 };
int featureflags = 0;
@ -1458,12 +1426,9 @@ zfs_send(zfs_handle_t *zhp, const char *fromsnap, const char *tosnap,
*debugnvp = hdrnv;
else
nvlist_free(hdrnv);
if (err) {
fsavl_destroy(fsavl);
nvlist_free(fss);
if (err)
goto stderr_out;
}
}
if (!flags->dryrun) {
/* write first begin record */
@ -1486,8 +1451,6 @@ zfs_send(zfs_handle_t *zhp, const char *fromsnap, const char *tosnap,
}
free(packbuf);
if (err == -1) {
fsavl_destroy(fsavl);
nvlist_free(fss);
err = errno;
goto stderr_out;
}
@ -1498,8 +1461,6 @@ zfs_send(zfs_handle_t *zhp, const char *fromsnap, const char *tosnap,
drr.drr_u.drr_end.drr_checksum = zc;
err = write(outfd, &drr, sizeof (drr));
if (err == -1) {
fsavl_destroy(fsavl);
nvlist_free(fss);
err = errno;
goto stderr_out;
}
@ -1511,7 +1472,7 @@ zfs_send(zfs_handle_t *zhp, const char *fromsnap, const char *tosnap,
/* dump each stream */
sdd.fromsnap = fromsnap;
sdd.tosnap = tosnap;
if (flags->dedup)
if (tid != 0)
sdd.outfd = pipefd[0];
else
sdd.outfd = outfd;
@ -1548,19 +1509,24 @@ zfs_send(zfs_handle_t *zhp, const char *fromsnap, const char *tosnap,
err = errno;
goto stderr_out;
}
sdd.snapholds = fnvlist_alloc();
} else {
sdd.cleanup_fd = -1;
sdd.snapholds = NULL;
}
if (flags->verbose) {
if (flags->verbose || sdd.snapholds != NULL) {
/*
* Do a verbose no-op dry run to get all the verbose output
* before generating any data. Then do a non-verbose real
* run to generate the streams.
* or to gather snapshot hold's before generating any data,
* then do a non-verbose real run to generate the streams.
*/
sdd.dryrun = B_TRUE;
err = dump_filesystems(zhp, &sdd);
sdd.dryrun = flags->dryrun;
sdd.verbose = B_FALSE;
if (err != 0)
goto stderr_out;
if (flags->verbose) {
if (flags->parsable) {
(void) fprintf(stderr, "size\t%llu\n",
(longlong_t)sdd.size);
@ -1571,13 +1537,43 @@ zfs_send(zfs_handle_t *zhp, const char *fromsnap, const char *tosnap,
"total estimated size is %s\n"), buf);
}
}
/* Ensure no snaps found is treated as an error. */
if (!sdd.seento) {
err = ENOENT;
goto err_out;
}
/* Skip the second run if dryrun was requested. */
if (flags->dryrun)
goto err_out;
if (sdd.snapholds != NULL) {
err = zfs_hold_nvl(zhp, sdd.cleanup_fd, sdd.snapholds);
if (err != 0)
goto stderr_out;
fnvlist_free(sdd.snapholds);
sdd.snapholds = NULL;
}
sdd.dryrun = B_FALSE;
sdd.verbose = B_FALSE;
}
err = dump_filesystems(zhp, &sdd);
fsavl_destroy(fsavl);
nvlist_free(fss);
if (flags->dedup) {
(void) close(pipefd[0]);
/* Ensure no snaps found is treated as an error. */
if (err == 0 && !sdd.seento)
err = ENOENT;
if (tid != 0) {
if (err != 0)
(void) pthread_cancel(tid);
(void) pthread_join(tid, NULL);
(void) close(pipefd[0]);
}
if (sdd.cleanup_fd != -1) {
@ -1605,9 +1601,13 @@ zfs_send(zfs_handle_t *zhp, const char *fromsnap, const char *tosnap,
stderr_out:
err = zfs_standard_error(zhp->zfs_hdl, err, errbuf);
err_out:
fsavl_destroy(fsavl);
nvlist_free(fss);
fnvlist_free(sdd.snapholds);
if (sdd.cleanup_fd != -1)
VERIFY(0 == close(sdd.cleanup_fd));
if (flags->dedup) {
if (tid != 0) {
(void) pthread_cancel(tid);
(void) pthread_join(tid, NULL);
(void) close(pipefd[0]);

47
lib/libzfs_core/libzfs_core.c
View File

@ -21,6 +21,7 @@
/*
* Copyright (c) 2012 by Delphix. All rights reserved.
* Copyright (c) 2013 Steven Hartland. All rights reserved.
*/
/*
@ -254,8 +255,11 @@ lzc_snapshot(nvlist_t *snaps, nvlist_t *props, nvlist_t **errlist)
* marked for deferred destruction, and will be destroyed when the last hold
* or clone is removed/destroyed.
*
* The return value will be ENOENT if none of the snapshots existed.
*
* The return value will be 0 if all snapshots were destroyed (or marked for
* later destruction if 'defer' is set) or didn't exist to begin with.
* later destruction if 'defer' is set) or didn't exist to begin with and
* at least one snapshot was destroyed.
*
* Otherwise the return value will be the errno of a (unspecified) snapshot
* that failed, no snapshots will be destroyed, and the errlist will have an
@ -286,7 +290,6 @@ lzc_destroy_snaps(nvlist_t *snaps, boolean_t defer, nvlist_t **errlist)
nvlist_free(args);
return (error);
}
int
@ -346,11 +349,22 @@ lzc_exists(const char *dataset)
* uncleanly, the holds will be released when the pool is next opened
* or imported.
*
* The return value will be 0 if all holds were created. Otherwise the return
* value will be the errno of a (unspecified) hold that failed, no holds will
* be created, and the errlist will have an entry for each hold that
* failed (name = snapshot). The value in the errlist will be the error
* code (int32).
* Holds for snapshots which don't exist will be skipped and have an entry
* added to errlist, but will not cause an overall failure, except in the
* case that all holds where skipped.
*
* The return value will be ENOENT if none of the snapshots for the requested
* holds existed.
*
* The return value will be 0 if the nvl holds was empty or all holds, for
* snapshots that existed, were succesfully created and at least one hold
* was created.
*
* Otherwise the return value will be the errno of a (unspecified) hold that
* failed and no holds will be created.
*
* In all cases the errlist will have an entry for each hold that failed
* (name = snapshot), with its value being the error code (int32).
*/
int
lzc_hold(nvlist_t *holds, int cleanup_fd, nvlist_t **errlist)
@ -387,11 +401,20 @@ lzc_hold(nvlist_t *holds, int cleanup_fd, nvlist_t **errlist)
* The snapshots must all be in the same pool.
* The value is a nvlist whose keys are the holds to remove.
*
* The return value will be 0 if all holds were removed.
* Otherwise the return value will be the errno of a (unspecified) release
* that failed, no holds will be released, and the errlist will have an
* entry for each snapshot that has failed releases (name = snapshot).
* The value in the errlist will be the error code (int32) of a failed release.
* Holds which failed to release because they didn't exist will have an entry
* added to errlist, but will not cause an overall failure, except in the
* case that all releases where skipped.
*
* The return value will be ENOENT if none of the specified holds existed.
*
* The return value will be 0 if the nvl holds was empty or all holds that
* existed, were successfully removed and at least one hold was removed.
*
* Otherwise the return value will be the errno of a (unspecified) hold that
* failed to release and no holds will be released.
*
* In all cases the errlist will have an entry for each hold that failed to
* to release.
*/
int
lzc_release(nvlist_t *holds, nvlist_t **errlist)

5
module/zfs/dsl_destroy.c
View File

@ -21,6 +21,7 @@
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2013 by Delphix. All rights reserved.
* Copyright (c) 2013 Steven Hartland. All rights reserved.
*/
#include <sys/zfs_context.h>
@ -127,6 +128,10 @@ dsl_destroy_snapshot_check(void *arg, dmu_tx_t *tx)
pair = nvlist_next_nvpair(dsda->dsda_errlist, NULL);
if (pair != NULL)
return (fnvpair_value_int32(pair));
if (nvlist_empty(dsda->dsda_successful_snaps))
return (SET_ERROR(ENOENT));
return (0);
}

18
module/zfs/dsl_pool.c
View File

@ -21,6 +21,7 @@
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2013 by Delphix. All rights reserved.
* Copyright (c) 2013 Steven Hartland. All rights reserved.
*/
#include <sys/dsl_pool.h>
@ -840,23 +841,34 @@ dsl_pool_clean_tmp_userrefs(dsl_pool_t *dp)
zap_cursor_t zc;
objset_t *mos = dp->dp_meta_objset;
uint64_t zapobj = dp->dp_tmp_userrefs_obj;
nvlist_t *holds;
if (zapobj == 0)
return;
ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
holds = fnvlist_alloc();
for (zap_cursor_init(&zc, mos, zapobj);
zap_cursor_retrieve(&zc, &za) == 0;
zap_cursor_advance(&zc)) {
char *htag;
uint64_t dsobj;
nvlist_t *tags;
htag = strchr(za.za_name, '-');
*htag = '\0';
++htag;
dsobj = strtonum(za.za_name, NULL);
dsl_dataset_user_release_tmp(dp, dsobj, htag);
if (nvlist_lookup_nvlist(holds, za.za_name, &tags) != 0) {
tags = fnvlist_alloc();
fnvlist_add_boolean(tags, htag);
fnvlist_add_nvlist(holds, za.za_name, tags);
fnvlist_free(tags);
} else {
fnvlist_add_boolean(tags, htag);
}
}
dsl_dataset_user_release_tmp(dp, holds);
fnvlist_free(holds);
zap_cursor_fini(&zc);
}

818
module/zfs/dsl_userhold.c
View File

@ -21,6 +21,7 @@
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2013 by Delphix. All rights reserved.
* Copyright (c) 2013 Steven Hartland. All rights reserved.
*/
#include <sys/zfs_context.h>
@ -37,6 +38,7 @@
typedef struct dsl_dataset_user_hold_arg {
nvlist_t *dduha_holds;
nvlist_t *dduha_chkholds;
nvlist_t *dduha_errlist;
minor_t dduha_minor;
} dsl_dataset_user_hold_arg_t;
@ -53,17 +55,18 @@ dsl_dataset_user_hold_check_one(dsl_dataset_t *ds, const char *htag,
objset_t *mos = dp->dp_meta_objset;
int error = 0;
ASSERT(dsl_pool_config_held(dp));
if (strlen(htag) > MAXNAMELEN)
return (E2BIG);
return (SET_ERROR(E2BIG));
/* Tempholds have a more restricted length */
if (temphold && strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN)
return (E2BIG);
return (SET_ERROR(E2BIG));
/* tags must be unique (if ds already exists) */
if (ds != NULL) {
mutex_enter(&ds->ds_lock);
if (ds->ds_phys->ds_userrefs_obj != 0) {
if (ds != NULL && ds->ds_phys->ds_userrefs_obj != 0) {
uint64_t value;
error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj,
htag, 8, 1, &value);
if (error == 0)
@ -71,8 +74,6 @@ dsl_dataset_user_hold_check_one(dsl_dataset_t *ds, const char *htag,
else if (error == ENOENT)
error = 0;
}
mutex_exit(&ds->ds_lock);
}
return (error);
}
@ -83,51 +84,67 @@ dsl_dataset_user_hold_check(void *arg, dmu_tx_t *tx)
dsl_dataset_user_hold_arg_t *dduha = arg;
dsl_pool_t *dp = dmu_tx_pool(tx);
nvpair_t *pair;
int rv = 0;
if (spa_version(dp->dp_spa) < SPA_VERSION_USERREFS)
return (SET_ERROR(ENOTSUP));
for (pair = nvlist_next_nvpair(dduha->dduha_holds, NULL); pair != NULL;
pair = nvlist_next_nvpair(dduha->dduha_holds, pair)) {
int error = 0;
if (!dmu_tx_is_syncing(tx))
return (0);
for (pair = nvlist_next_nvpair(dduha->dduha_holds, NULL);
pair != NULL; pair = nvlist_next_nvpair(dduha->dduha_holds, pair)) {
dsl_dataset_t *ds;
char *htag;
int error = 0;
char *htag, *name;
/* must be a snapshot */
if (strchr(nvpair_name(pair), '@') == NULL)
name = nvpair_name(pair);
if (strchr(name, '@') == NULL)
error = SET_ERROR(EINVAL);
if (error == 0)
error = nvpair_value_string(pair, &htag);
if (error == 0) {
error = dsl_dataset_hold(dp,
nvpair_name(pair), FTAG, &ds);
}
if (error == 0)
error = dsl_dataset_hold(dp, name, FTAG, &ds);
if (error == 0) {
error = dsl_dataset_user_hold_check_one(ds, htag,
dduha->dduha_minor != 0, tx);
dsl_dataset_rele(ds, FTAG);
}
if (error != 0) {
rv = error;
fnvlist_add_int32(dduha->dduha_errlist,
nvpair_name(pair), error);
if (error == 0) {
fnvlist_add_string(dduha->dduha_chkholds, name, htag);
} else {
/*
* We register ENOENT errors so they can be correctly
* reported if needed, such as when all holds fail.
*/
fnvlist_add_int32(dduha->dduha_errlist, name, error);
if (error != ENOENT)
return (error);
}
}
return (rv);
}
void
dsl_dataset_user_hold_sync_one(dsl_dataset_t *ds, const char *htag,
minor_t minor, uint64_t now, dmu_tx_t *tx)
/* Return ENOENT if no holds would be created. */
if (nvlist_empty(dduha->dduha_chkholds))
return (SET_ERROR(ENOENT));
return (0);
}
static void
dsl_dataset_user_hold_sync_one_impl(nvlist_t *tmpholds, dsl_dataset_t *ds,
const char *htag, minor_t minor, uint64_t now, dmu_tx_t *tx)
{
dsl_pool_t *dp = ds->ds_dir->dd_pool;
objset_t *mos = dp->dp_meta_objset;
uint64_t zapobj;
mutex_enter(&ds->ds_lock);
ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
if (ds->ds_phys->ds_userrefs_obj == 0) {
/*
* This is the first user hold for this dataset. Create
@ -140,14 +157,26 @@ dsl_dataset_user_hold_sync_one(dsl_dataset_t *ds, const char *htag,
zapobj = ds->ds_phys->ds_userrefs_obj;
}
ds->ds_userrefs++;
mutex_exit(&ds->ds_lock);
VERIFY0(zap_add(mos, zapobj, htag, 8, 1, &now, tx));
if (minor != 0) {
char name[MAXNAMELEN];
nvlist_t *tags;
VERIFY0(dsl_pool_user_hold(dp, ds->ds_object,
htag, now, tx));
dsl_register_onexit_hold_cleanup(ds, htag, minor);
(void) snprintf(name, sizeof (name), "%llx",
(u_longlong_t)ds->ds_object);
if (nvlist_lookup_nvlist(tmpholds, name, &tags) != 0) {
tags = fnvlist_alloc();
fnvlist_add_boolean(tags, htag);
fnvlist_add_nvlist(tmpholds, name, tags);
fnvlist_free(tags);
} else {
fnvlist_add_boolean(tags, htag);
}
}
spa_history_log_internal_ds(ds, "hold", tx,
@ -155,306 +184,10 @@ dsl_dataset_user_hold_sync_one(dsl_dataset_t *ds, const char *htag,
htag, minor != 0, ds->ds_userrefs);
}
static void
dsl_dataset_user_hold_sync(void *arg, dmu_tx_t *tx)
{
dsl_dataset_user_hold_arg_t *dduha = arg;
dsl_pool_t *dp = dmu_tx_pool(tx);
nvpair_t *pair;
uint64_t now = gethrestime_sec();
for (pair = nvlist_next_nvpair(dduha->dduha_holds, NULL); pair != NULL;
pair = nvlist_next_nvpair(dduha->dduha_holds, pair)) {
dsl_dataset_t *ds;
VERIFY0(dsl_dataset_hold(dp, nvpair_name(pair), FTAG, &ds));
dsl_dataset_user_hold_sync_one(ds, fnvpair_value_string(pair),
dduha->dduha_minor, now, tx);
dsl_dataset_rele(ds, FTAG);
}
}
/*
* holds is nvl of snapname -> holdname
* errlist will be filled in with snapname -> error
* if cleanup_minor is not 0, the holds will be temporary, cleaned up
* when the process exits.
*
* if any fails, all will fail.
*/
int
dsl_dataset_user_hold(nvlist_t *holds, minor_t cleanup_minor, nvlist_t *errlist)
{
dsl_dataset_user_hold_arg_t dduha;
nvpair_t *pair;
pair = nvlist_next_nvpair(holds, NULL);
if (pair == NULL)
return (0);
dduha.dduha_holds = holds;
dduha.dduha_errlist = errlist;
dduha.dduha_minor = cleanup_minor;
return (dsl_sync_task(nvpair_name(pair), dsl_dataset_user_hold_check,
dsl_dataset_user_hold_sync, &dduha, fnvlist_num_pairs(holds)));
}
typedef struct dsl_dataset_user_release_arg {
nvlist_t *ddura_holds;
nvlist_t *ddura_todelete;
nvlist_t *ddura_errlist;
} dsl_dataset_user_release_arg_t;
static int
dsl_dataset_user_release_check_one(dsl_dataset_t *ds,
nvlist_t *holds, boolean_t *todelete)
{
uint64_t zapobj;
nvpair_t *pair;
objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
int error;
int numholds = 0;
*todelete = B_FALSE;
if (!dsl_dataset_is_snapshot(ds))
return (SET_ERROR(EINVAL));
zapobj = ds->ds_phys->ds_userrefs_obj;
if (zapobj == 0)
return (SET_ERROR(ESRCH));
for (pair = nvlist_next_nvpair(holds, NULL); pair != NULL;
pair = nvlist_next_nvpair(holds, pair)) {
/* Make sure the hold exists */
uint64_t tmp;
error = zap_lookup(mos, zapobj, nvpair_name(pair), 8, 1, &tmp);
if (error == ENOENT)
error = SET_ERROR(ESRCH);
if (error != 0)
return (error);
numholds++;
}
if (DS_IS_DEFER_DESTROY(ds) && ds->ds_phys->ds_num_children == 1 &&
ds->ds_userrefs == numholds) {
/* we need to destroy the snapshot as well */
if (dsl_dataset_long_held(ds))
return (SET_ERROR(EBUSY));
*todelete = B_TRUE;
}
return (0);
}
static int
dsl_dataset_user_release_check(void *arg, dmu_tx_t *tx)
{
dsl_dataset_user_release_arg_t *ddura = arg;
dsl_pool_t *dp = dmu_tx_pool(tx);
nvpair_t *pair;
int rv = 0;
if (!dmu_tx_is_syncing(tx))
return (0);
for (pair = nvlist_next_nvpair(ddura->ddura_holds, NULL); pair != NULL;
pair = nvlist_next_nvpair(ddura->ddura_holds, pair)) {
const char *name = nvpair_name(pair);
int error;
dsl_dataset_t *ds;
nvlist_t *holds;
error = nvpair_value_nvlist(pair, &holds);
if (error != 0)
return (SET_ERROR(EINVAL));
error = dsl_dataset_hold(dp, name, FTAG, &ds);
if (error == 0) {
boolean_t deleteme;
error = dsl_dataset_user_release_check_one(ds,
holds, &deleteme);
if (error == 0 && deleteme) {
fnvlist_add_boolean(ddura->ddura_todelete,
name);
}
dsl_dataset_rele(ds, FTAG);
}
if (error != 0) {
if (ddura->ddura_errlist != NULL) {
fnvlist_add_int32(ddura->ddura_errlist,
name, error);
}
rv = error;
}
}
return (rv);
}
static void
dsl_dataset_user_release_sync_one(dsl_dataset_t *ds, nvlist_t *holds,
dmu_tx_t *tx)
{
dsl_pool_t *dp = ds->ds_dir->dd_pool;
objset_t *mos = dp->dp_meta_objset;
uint64_t zapobj;
int error;
nvpair_t *pair;
for (pair = nvlist_next_nvpair(holds, NULL); pair != NULL;
pair = nvlist_next_nvpair(holds, pair)) {
ds->ds_userrefs--;
error = dsl_pool_user_release(dp, ds->ds_object,
nvpair_name(pair), tx);
VERIFY(error == 0 || error == ENOENT);
zapobj = ds->ds_phys->ds_userrefs_obj;
VERIFY0(zap_remove(mos, zapobj, nvpair_name(pair), tx));
spa_history_log_internal_ds(ds, "release", tx,
"tag=%s refs=%lld", nvpair_name(pair),
(longlong_t)ds->ds_userrefs);
}
}
static void
dsl_dataset_user_release_sync(void *arg, dmu_tx_t *tx)
{
dsl_dataset_user_release_arg_t *ddura = arg;
dsl_pool_t *dp = dmu_tx_pool(tx);
nvpair_t *pair;
for (pair = nvlist_next_nvpair(ddura->ddura_holds, NULL); pair != NULL;
pair = nvlist_next_nvpair(ddura->ddura_holds, pair)) {
dsl_dataset_t *ds;
VERIFY0(dsl_dataset_hold(dp, nvpair_name(pair), FTAG, &ds));
dsl_dataset_user_release_sync_one(ds,
fnvpair_value_nvlist(pair), tx);
if (nvlist_exists(ddura->ddura_todelete,
nvpair_name(pair))) {
ASSERT(ds->ds_userrefs == 0 &&
ds->ds_phys->ds_num_children == 1 &&
DS_IS_DEFER_DESTROY(ds));
dsl_destroy_snapshot_sync_impl(ds, B_FALSE, tx);
}
dsl_dataset_rele(ds, FTAG);
}
}
/*
* holds is nvl of snapname -> { holdname, ... }
* errlist will be filled in with snapname -> error
*
* if any fails, all will fail.
*/
int
dsl_dataset_user_release(nvlist_t *holds, nvlist_t *errlist)
{
dsl_dataset_user_release_arg_t ddura;
nvpair_t *pair;
int error;
pair = nvlist_next_nvpair(holds, NULL);
if (pair == NULL)
return (0);
ddura.ddura_holds = holds;
ddura.ddura_errlist = errlist;
ddura.ddura_todelete = fnvlist_alloc();
error = dsl_sync_task(nvpair_name(pair), dsl_dataset_user_release_check,
dsl_dataset_user_release_sync, &ddura, fnvlist_num_pairs(holds));
fnvlist_free(ddura.ddura_todelete);
return (error);
}
typedef struct dsl_dataset_user_release_tmp_arg {
uint64_t ddurta_dsobj;
nvlist_t *ddurta_holds;
boolean_t ddurta_deleteme;
} dsl_dataset_user_release_tmp_arg_t;
static int
dsl_dataset_user_release_tmp_check(void *arg, dmu_tx_t *tx)
{
dsl_dataset_user_release_tmp_arg_t *ddurta = arg;
dsl_pool_t *dp = dmu_tx_pool(tx);
dsl_dataset_t *ds;
int error;
if (!dmu_tx_is_syncing(tx))
return (0);
error = dsl_dataset_hold_obj(dp, ddurta->ddurta_dsobj, FTAG, &ds);
if (error)
return (error);
error = dsl_dataset_user_release_check_one(ds,
ddurta->ddurta_holds, &ddurta->ddurta_deleteme);
dsl_dataset_rele(ds, FTAG);
return (error);
}
static void
dsl_dataset_user_release_tmp_sync(void *arg, dmu_tx_t *tx)
{
dsl_dataset_user_release_tmp_arg_t *ddurta = arg;
dsl_pool_t *dp = dmu_tx_pool(tx);
dsl_dataset_t *ds;
VERIFY0(dsl_dataset_hold_obj(dp, ddurta->ddurta_dsobj, FTAG, &ds));
dsl_dataset_user_release_sync_one(ds, ddurta->ddurta_holds, tx);
if (ddurta->ddurta_deleteme) {
ASSERT(ds->ds_userrefs == 0 &&
ds->ds_phys->ds_num_children == 1 &&
DS_IS_DEFER_DESTROY(ds));
dsl_destroy_snapshot_sync_impl(ds, B_FALSE, tx);
}
dsl_dataset_rele(ds, FTAG);
}
/*
* Called at spa_load time to release a stale temporary user hold.
* Also called by the onexit code.
*/
void
dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, const char *htag)
{
dsl_dataset_user_release_tmp_arg_t ddurta;
#ifdef _KERNEL
dsl_dataset_t *ds;
int error;
/* Make sure it is not mounted. */
dsl_pool_config_enter(dp, FTAG);
error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds);
if (error == 0) {
char name[MAXNAMELEN];
dsl_dataset_name(ds, name);
dsl_dataset_rele(ds, FTAG);
dsl_pool_config_exit(dp, FTAG);
(void) zfs_unmount_snap(name);
} else {
dsl_pool_config_exit(dp, FTAG);
}
#endif
ddurta.ddurta_dsobj = dsobj;
ddurta.ddurta_holds = fnvlist_alloc();
fnvlist_add_boolean(ddurta.ddurta_holds, htag);
(void) dsl_sync_task(spa_name(dp->dp_spa),
dsl_dataset_user_release_tmp_check,
dsl_dataset_user_release_tmp_sync, &ddurta, 1);
fnvlist_free(ddurta.ddurta_holds);
}
typedef struct zfs_hold_cleanup_arg {
char zhca_spaname[MAXNAMELEN];
uint64_t zhca_spa_load_guid;
uint64_t zhca_dsobj;
char zhca_htag[MAXNAMELEN];
nvlist_t *zhca_holds;
} zfs_hold_cleanup_arg_t;
static void
@ -466,40 +199,447 @@ dsl_dataset_user_release_onexit(void *arg)
error = spa_open(ca->zhca_spaname, &spa, FTAG);
if (error != 0) {
zfs_dbgmsg("couldn't release hold on pool=%s ds=%llu tag=%s "
zfs_dbgmsg("couldn't release holds on pool=%s "
"because pool is no longer loaded",
ca->zhca_spaname, ca->zhca_dsobj, ca->zhca_htag);
ca->zhca_spaname);
return;
}
if (spa_load_guid(spa) != ca->zhca_spa_load_guid) {
zfs_dbgmsg("couldn't release hold on pool=%s ds=%llu tag=%s "
zfs_dbgmsg("couldn't release holds on pool=%s "
"because pool is no longer loaded (guid doesn't match)",
ca->zhca_spaname, ca->zhca_dsobj, ca->zhca_htag);
ca->zhca_spaname);
spa_close(spa, FTAG);
return;
}
dsl_dataset_user_release_tmp(spa_get_dsl(spa),
ca->zhca_dsobj, ca->zhca_htag);
(void) dsl_dataset_user_release_tmp(spa_get_dsl(spa), ca->zhca_holds);
fnvlist_free(ca->zhca_holds);
kmem_free(ca, sizeof (zfs_hold_cleanup_arg_t));
spa_close(spa, FTAG);
}
void
dsl_register_onexit_hold_cleanup(dsl_dataset_t *ds, const char *htag,
minor_t minor)
static void
dsl_onexit_hold_cleanup(spa_t *spa, nvlist_t *holds, minor_t minor)
{
zfs_hold_cleanup_arg_t *ca = kmem_alloc(sizeof (*ca), KM_PUSHPAGE);
spa_t *spa = dsl_dataset_get_spa(ds);
zfs_hold_cleanup_arg_t *ca;
if (minor == 0 || nvlist_empty(holds)) {
fnvlist_free(holds);
return;
}
ASSERT(spa != NULL);
ca = kmem_alloc(sizeof (*ca), KM_SLEEP);
(void) strlcpy(ca->zhca_spaname, spa_name(spa),
sizeof (ca->zhca_spaname));
ca->zhca_spa_load_guid = spa_load_guid(spa);
ca->zhca_dsobj = ds->ds_object;
(void) strlcpy(ca->zhca_htag, htag, sizeof (ca->zhca_htag));
ca->zhca_holds = holds;
VERIFY0(zfs_onexit_add_cb(minor,
dsl_dataset_user_release_onexit, ca, NULL));
}
void
dsl_dataset_user_hold_sync_one(dsl_dataset_t *ds, const char *htag,
minor_t minor, uint64_t now, dmu_tx_t *tx)
{
nvlist_t *tmpholds;
if (minor != 0)
tmpholds = fnvlist_alloc();
else
tmpholds = NULL;
dsl_dataset_user_hold_sync_one_impl(tmpholds, ds, htag, minor, now, tx);
dsl_onexit_hold_cleanup(dsl_dataset_get_spa(ds), tmpholds, minor);
}
static void
dsl_dataset_user_hold_sync(void *arg, dmu_tx_t *tx)
{
dsl_dataset_user_hold_arg_t *dduha = arg;
dsl_pool_t *dp = dmu_tx_pool(tx);
nvlist_t *tmpholds;
nvpair_t *pair;
uint64_t now = gethrestime_sec();
if (dduha->dduha_minor != 0)
tmpholds = fnvlist_alloc();
else
tmpholds = NULL;
for (pair = nvlist_next_nvpair(dduha->dduha_chkholds, NULL);
pair != NULL;
pair = nvlist_next_nvpair(dduha->dduha_chkholds, pair)) {
dsl_dataset_t *ds;
VERIFY0(dsl_dataset_hold(dp, nvpair_name(pair), FTAG, &ds));
dsl_dataset_user_hold_sync_one_impl(tmpholds, ds,
fnvpair_value_string(pair), dduha->dduha_minor, now, tx);
dsl_dataset_rele(ds, FTAG);
}
dsl_onexit_hold_cleanup(dp->dp_spa, tmpholds, dduha->dduha_minor);
}
/*
* The full semantics of this function are described in the comment above
* lzc_hold().
*
* To summarize:
* holds is nvl of snapname -> holdname
* errlist will be filled in with snapname -> error
*
* The snaphosts must all be in the same pool.
*
* Holds for snapshots that don't exist will be skipped.
*
* If none of the snapshots for requested holds exist then ENOENT will be
* returned.
*
* If cleanup_minor is not 0, the holds will be temporary, which will be cleaned
* up when the process exits.
*
* On success all the holds, for snapshots that existed, will be created and 0
* will be returned.
*
* On failure no holds will be created, the errlist will be filled in,
* and an errno will returned.
*
* In all cases the errlist will contain entries for holds where the snapshot
* didn't exist.
*/
int
dsl_dataset_user_hold(nvlist_t *holds, minor_t cleanup_minor, nvlist_t *errlist)
{
dsl_dataset_user_hold_arg_t dduha;
nvpair_t *pair;
int ret;
pair = nvlist_next_nvpair(holds, NULL);
if (pair == NULL)
return (0);
dduha.dduha_holds = holds;
dduha.dduha_chkholds = fnvlist_alloc();
dduha.dduha_errlist = errlist;
dduha.dduha_minor = cleanup_minor;
ret = dsl_sync_task(nvpair_name(pair), dsl_dataset_user_hold_check,
dsl_dataset_user_hold_sync, &dduha, fnvlist_num_pairs(holds));
fnvlist_free(dduha.dduha_chkholds);
return (ret);
}
typedef int (dsl_holdfunc_t)(dsl_pool_t *dp, const char *name, void *tag,
dsl_dataset_t **dsp);
typedef struct dsl_dataset_user_release_arg {
dsl_holdfunc_t *ddura_holdfunc;
nvlist_t *ddura_holds;
nvlist_t *ddura_todelete;
nvlist_t *ddura_errlist;
nvlist_t *ddura_chkholds;
} dsl_dataset_user_release_arg_t;
/* Place a dataset hold on the snapshot identified by passed dsobj string */
static int
dsl_dataset_hold_obj_string(dsl_pool_t *dp, const char *dsobj, void *tag,
dsl_dataset_t **dsp)
{
return (dsl_dataset_hold_obj(dp, strtonum(dsobj, NULL), tag, dsp));
}
static int
dsl_dataset_user_release_check_one(dsl_dataset_user_release_arg_t *ddura,
dsl_dataset_t *ds, nvlist_t *holds, const char *snapname)
{
uint64_t zapobj;
nvlist_t *holds_found;
nvpair_t *pair;
objset_t *mos;
int numholds;
if (!dsl_dataset_is_snapshot(ds))
return (SET_ERROR(EINVAL));
if (nvlist_empty(holds))
return (0);
numholds = 0;
mos = ds->ds_dir->dd_pool->dp_meta_objset;
zapobj = ds->ds_phys->ds_userrefs_obj;
holds_found = fnvlist_alloc();
for (pair = nvlist_next_nvpair(holds, NULL); pair != NULL;
pair = nvlist_next_nvpair(holds, pair)) {
uint64_t tmp;
int error;
const char *holdname = nvpair_name(pair);
if (zapobj != 0)
error = zap_lookup(mos, zapobj, holdname, 8, 1, &tmp);
else
error = SET_ERROR(ENOENT);
/*
* Non-existent holds are put on the errlist, but don't
* cause an overall failure.
*/
if (error == ENOENT) {
if (ddura->ddura_errlist != NULL) {
char *errtag = kmem_asprintf("%s#%s",
snapname, holdname);
fnvlist_add_int32(ddura->ddura_errlist, errtag,
ENOENT);
strfree(errtag);
}
continue;
}
if (error != 0) {
fnvlist_free(holds_found);
return (error);
}
fnvlist_add_boolean(holds_found, holdname);
numholds++;
}
if (DS_IS_DEFER_DESTROY(ds) && ds->ds_phys->ds_num_children == 1 &&
ds->ds_userrefs == numholds) {
/* we need to destroy the snapshot as well */
if (dsl_dataset_long_held(ds)) {
fnvlist_free(holds_found);
return (SET_ERROR(EBUSY));
}
fnvlist_add_boolean(ddura->ddura_todelete, snapname);
}
if (numholds != 0) {
fnvlist_add_nvlist(ddura->ddura_chkholds, snapname,
holds_found);
}
fnvlist_free(holds_found);
return (0);
}
static int
dsl_dataset_user_release_check(void *arg, dmu_tx_t *tx)
{
dsl_dataset_user_release_arg_t *ddura;
dsl_holdfunc_t *holdfunc;
dsl_pool_t *dp;
nvpair_t *pair;
if (!dmu_tx_is_syncing(tx))
return (0);
dp = dmu_tx_pool(tx);
ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
ddura = arg;
holdfunc = ddura->ddura_holdfunc;
for (pair = nvlist_next_nvpair(ddura->ddura_holds, NULL);
pair != NULL; pair = nvlist_next_nvpair(ddura->ddura_holds, pair)) {
int error;
dsl_dataset_t *ds;
nvlist_t *holds;
const char *snapname = nvpair_name(pair);
error = nvpair_value_nvlist(pair, &holds);
if (error != 0)
error = (SET_ERROR(EINVAL));
else
error = holdfunc(dp, snapname, FTAG, &ds);
if (error == 0) {
error = dsl_dataset_user_release_check_one(ddura, ds,
holds, snapname);
dsl_dataset_rele(ds, FTAG);
}
if (error != 0) {
if (ddura->ddura_errlist != NULL) {
fnvlist_add_int32(ddura->ddura_errlist,
snapname, error);
}
/*
* Non-existent snapshots are put on the errlist,
* but don't cause an overall failure.
*/
if (error != ENOENT)
return (error);
}
}
/* Return ENOENT if none of the holds existed. */
if (nvlist_empty(ddura->ddura_chkholds))
return (SET_ERROR(ENOENT));
return (0);
}
static void
dsl_dataset_user_release_sync_one(dsl_dataset_t *ds, nvlist_t *holds,
dmu_tx_t *tx)
{
dsl_pool_t *dp = ds->ds_dir->dd_pool;
objset_t *mos = dp->dp_meta_objset;
nvpair_t *pair;
for (pair = nvlist_next_nvpair(holds, NULL); pair != NULL;
pair = nvlist_next_nvpair(holds, pair)) {
int error;
const char *holdname = nvpair_name(pair);
/* Remove temporary hold if one exists. */
error = dsl_pool_user_release(dp, ds->ds_object, holdname, tx);
VERIFY(error == 0 || error == ENOENT);
VERIFY0(zap_remove(mos, ds->ds_phys->ds_userrefs_obj, holdname,
tx));
ds->ds_userrefs--;
spa_history_log_internal_ds(ds, "release", tx,
"tag=%s refs=%lld", holdname, (longlong_t)ds->ds_userrefs);
}
}
static void
dsl_dataset_user_release_sync(void *arg, dmu_tx_t *tx)
{
dsl_dataset_user_release_arg_t *ddura = arg;
dsl_holdfunc_t *holdfunc = ddura->ddura_holdfunc;
dsl_pool_t *dp = dmu_tx_pool(tx);
nvpair_t *pair;
ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
for (pair = nvlist_next_nvpair(ddura->ddura_chkholds, NULL);
pair != NULL; pair = nvlist_next_nvpair(ddura->ddura_chkholds,
pair)) {
dsl_dataset_t *ds;
const char *name = nvpair_name(pair);
VERIFY0(holdfunc(dp, name, FTAG, &ds));
dsl_dataset_user_release_sync_one(ds,
fnvpair_value_nvlist(pair), tx);
if (nvlist_exists(ddura->ddura_todelete, name)) {
ASSERT(ds->ds_userrefs == 0 &&
ds->ds_phys->ds_num_children == 1 &&
DS_IS_DEFER_DESTROY(ds));
dsl_destroy_snapshot_sync_impl(ds, B_FALSE, tx);
}
dsl_dataset_rele(ds, FTAG);
}
}
/*
* The full semantics of this function are described in the comment above
* lzc_release().
*
* To summarize:
* Releases holds specified in the nvl holds.
*
* holds is nvl of snapname -> { holdname, ... }
* errlist will be filled in with snapname -> error
*
* If tmpdp is not NULL the names for holds should be the dsobj's of snapshots,
* otherwise they should be the names of shapshots.
*
* As a release may cause snapshots to be destroyed this trys to ensure they
* aren't mounted.
*
* The release of non-existent holds are skipped.
*
* At least one hold must have been released for the this function to succeed
* and return 0.
*/
static int
dsl_dataset_user_release_impl(nvlist_t *holds, nvlist_t *errlist,
dsl_pool_t *tmpdp)
{
dsl_dataset_user_release_arg_t ddura;
nvpair_t *pair;
char *pool;
int error;
pair = nvlist_next_nvpair(holds, NULL);
if (pair == NULL)
return (0);
/*
* The release may cause snapshots to be destroyed; make sure they
* are not mounted.
*/
if (tmpdp != NULL) {
/* Temporary holds are specified by dsobj string. */
ddura.ddura_holdfunc = dsl_dataset_hold_obj_string;
pool = spa_name(tmpdp->dp_spa);
#ifdef _KERNEL
dsl_pool_config_enter(tmpdp, FTAG);
for (pair = nvlist_next_nvpair(holds, NULL); pair != NULL;
pair = nvlist_next_nvpair(holds, pair)) {
dsl_dataset_t *ds;
error = dsl_dataset_hold_obj_string(tmpdp,
nvpair_name(pair), FTAG, &ds);
if (error == 0) {
char name[MAXNAMELEN];
dsl_dataset_name(ds, name);
dsl_dataset_rele(ds, FTAG);
(void) zfs_unmount_snap(name);
}
}
dsl_pool_config_exit(tmpdp, FTAG);
#endif
} else {
/* Non-temporary holds are specified by name. */
ddura.ddura_holdfunc = dsl_dataset_hold;
pool = nvpair_name(pair);
#ifdef _KERNEL
for (pair = nvlist_next_nvpair(holds, NULL); pair != NULL;
pair = nvlist_next_nvpair(holds, pair)) {
(void) zfs_unmount_snap(nvpair_name(pair));
}
#endif
}
ddura.ddura_holds = holds;
ddura.ddura_errlist = errlist;
ddura.ddura_todelete = fnvlist_alloc();
ddura.ddura_chkholds = fnvlist_alloc();
error = dsl_sync_task(pool, dsl_dataset_user_release_check,
dsl_dataset_user_release_sync, &ddura,
fnvlist_num_pairs(holds));
fnvlist_free(ddura.ddura_todelete);
fnvlist_free(ddura.ddura_chkholds);
return (error);
}
/*
* holds is nvl of snapname -> { holdname, ... }
* errlist will be filled in with snapname -> error
*/
int
dsl_dataset_user_release(nvlist_t *holds, nvlist_t *errlist)
{
return (dsl_dataset_user_release_impl(holds, errlist, NULL));
}
/*
* holds is nvl of snapdsobj -> { holdname, ... }
*/
void
dsl_dataset_user_release_tmp(struct dsl_pool *dp, nvlist_t *holds)
{
ASSERT(dp != NULL);
(void) dsl_dataset_user_release_impl(holds, NULL, dp);
}
int
dsl_dataset_get_holds(const char *dsname, nvlist_t *nvl)
{

15
module/zfs/zfs_ioctl.c
View File

@ -28,6 +28,7 @@
* Copyright (c) 2012, Joyent, Inc. All rights reserved.
* Copyright (c) 201i3 by Delphix. All rights reserved.
* Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
* Copyright (c) 2013 Steven Hartland. All rights reserved.
*/
/*
@ -4867,20 +4868,6 @@ zfs_ioc_get_holds(const char *snapname, nvlist_t *args, nvlist_t *outnvl)
static int
zfs_ioc_release(const char *pool, nvlist_t *holds, nvlist_t *errlist)
{
nvpair_t *pair;
int err;
/*
* The release may cause the snapshot to be destroyed; make sure it
* is not mounted.
*/
for (pair = nvlist_next_nvpair(holds, NULL); pair != NULL;
pair = nvlist_next_nvpair(holds, pair)) {
err = zfs_unmount_snap(nvpair_name(pair));
if (err != 0)
return (err);
}
return (dsl_dataset_user_release(holds, errlist));
}