diff options
Diffstat (limited to 'module/zfs/dsl_userhold.c')
| -rw-r--r-- | module/zfs/dsl_userhold.c | 537 |
1 files changed, 537 insertions, 0 deletions
diff --git a/module/zfs/dsl_userhold.c b/module/zfs/dsl_userhold.c new file mode 100644 index 000000000..c8bc4424f --- /dev/null +++ b/module/zfs/dsl_userhold.c @@ -0,0 +1,537 @@ +/* + * CDDL HEADER START + * + * The contents of this file are subject to the terms of the + * Common Development and Distribution License (the "License"). + * You may not use this file except in compliance with the License. + * + * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE + * or http://www.opensolaris.org/os/licensing. + * See the License for the specific language governing permissions + * and limitations under the License. + * + * When distributing Covered Code, include this CDDL HEADER in each + * file and include the License file at usr/src/OPENSOLARIS.LICENSE. + * If applicable, add the following below this CDDL HEADER, with the + * fields enclosed by brackets "[]" replaced with your own identifying + * information: Portions Copyright [yyyy] [name of copyright owner] + * + * CDDL HEADER END + */ +/* + * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2012 by Delphix. All rights reserved. + */ + +#include <sys/zfs_context.h> +#include <sys/dsl_userhold.h> +#include <sys/dsl_dataset.h> +#include <sys/dsl_destroy.h> +#include <sys/dsl_synctask.h> +#include <sys/dmu_tx.h> +#include <sys/zfs_onexit.h> +#include <sys/dsl_pool.h> +#include <sys/dsl_dir.h> +#include <sys/zfs_ioctl.h> +#include <sys/zap.h> + +typedef struct dsl_dataset_user_hold_arg { + nvlist_t *dduha_holds; + nvlist_t *dduha_errlist; + minor_t dduha_minor; +} dsl_dataset_user_hold_arg_t; + +/* + * If you add new checks here, you may need to add additional checks to the + * "temporary" case in snapshot_check() in dmu_objset.c. + */ +int +dsl_dataset_user_hold_check_one(dsl_dataset_t *ds, const char *htag, + boolean_t temphold, dmu_tx_t *tx) +{ + dsl_pool_t *dp = dmu_tx_pool(tx); + objset_t *mos = dp->dp_meta_objset; + int error = 0; + + if (strlen(htag) > MAXNAMELEN) + return (E2BIG); + /* Tempholds have a more restricted length */ + if (temphold && strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN) + return (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) { + uint64_t value; + error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj, + htag, 8, 1, &value); + if (error == 0) + error = EEXIST; + else if (error == ENOENT) + error = 0; + } + mutex_exit(&ds->ds_lock); + } + + return (error); +} + +static int +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 (ENOTSUP); + + for (pair = nvlist_next_nvpair(dduha->dduha_holds, NULL); pair != NULL; + pair = nvlist_next_nvpair(dduha->dduha_holds, pair)) { + int error = 0; + dsl_dataset_t *ds; + char *htag; + + /* must be a snapshot */ + if (strchr(nvpair_name(pair), '@') == NULL) + 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_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); + } + } + 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) +{ + dsl_pool_t *dp = ds->ds_dir->dd_pool; + objset_t *mos = dp->dp_meta_objset; + uint64_t zapobj; + + mutex_enter(&ds->ds_lock); + if (ds->ds_phys->ds_userrefs_obj == 0) { + /* + * This is the first user hold for this dataset. Create + * the userrefs zap object. + */ + dmu_buf_will_dirty(ds->ds_dbuf, tx); + zapobj = ds->ds_phys->ds_userrefs_obj = + zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx); + } else { + 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) { + VERIFY0(dsl_pool_user_hold(dp, ds->ds_object, + htag, now, tx)); + dsl_register_onexit_hold_cleanup(ds, htag, minor); + } + + spa_history_log_internal_ds(ds, "hold", tx, + "tag=%s temp=%d refs=%llu", + 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 (EINVAL); + + zapobj = ds->ds_phys->ds_userrefs_obj; + if (zapobj == 0) + return (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 = 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 (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 (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); + 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]; +} zfs_hold_cleanup_arg_t; + +static void +dsl_dataset_user_release_onexit(void *arg) +{ + zfs_hold_cleanup_arg_t *ca = arg; + spa_t *spa; + int error; + + error = spa_open(ca->zhca_spaname, &spa, FTAG); + if (error != 0) { + zfs_dbgmsg("couldn't release hold on pool=%s ds=%llu tag=%s " + "because pool is no longer loaded", + ca->zhca_spaname, ca->zhca_dsobj, ca->zhca_htag); + return; + } + if (spa_load_guid(spa) != ca->zhca_spa_load_guid) { + zfs_dbgmsg("couldn't release hold on pool=%s ds=%llu tag=%s " + "because pool is no longer loaded (guid doesn't match)", + ca->zhca_spaname, ca->zhca_dsobj, ca->zhca_htag); + spa_close(spa, FTAG); + return; + } + + dsl_dataset_user_release_tmp(spa_get_dsl(spa), + ca->zhca_dsobj, ca->zhca_htag); + 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) +{ + zfs_hold_cleanup_arg_t *ca = kmem_alloc(sizeof (*ca), KM_SLEEP); + spa_t *spa = dsl_dataset_get_spa(ds); + (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)); + VERIFY0(zfs_onexit_add_cb(minor, + dsl_dataset_user_release_onexit, ca, NULL)); +} + +int +dsl_dataset_get_holds(const char *dsname, nvlist_t *nvl) +{ + dsl_pool_t *dp; + dsl_dataset_t *ds; + int err; + + err = dsl_pool_hold(dsname, FTAG, &dp); + if (err != 0) + return (err); + err = dsl_dataset_hold(dp, dsname, FTAG, &ds); + if (err != 0) { + dsl_pool_rele(dp, FTAG); + return (err); + } + + if (ds->ds_phys->ds_userrefs_obj != 0) { + zap_attribute_t *za; + zap_cursor_t zc; + + za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP); + for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset, + ds->ds_phys->ds_userrefs_obj); + zap_cursor_retrieve(&zc, za) == 0; + zap_cursor_advance(&zc)) { + fnvlist_add_uint64(nvl, za->za_name, + za->za_first_integer); + } + zap_cursor_fini(&zc); + kmem_free(za, sizeof (zap_attribute_t)); + } + dsl_dataset_rele(ds, FTAG); + dsl_pool_rele(dp, FTAG); + return (0); +} |