/*
* 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);
}
/*
* 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
for (pair = nvlist_next_nvpair(holds, NULL); pair != NULL;
pair = nvlist_next_nvpair(holds, pair)) {
dsl_dataset_t *ds;
dsl_pool_config_enter(tmpdp, FTAG);
error = dsl_dataset_hold_obj_string(tmpdp,
nvpair_name(pair), FTAG, &ds);
if (error == 0) {
char name[MAXNAMELEN];
dsl_dataset_name(ds, name);
dsl_pool_config_exit(tmpdp, FTAG);
dsl_dataset_rele(ds, FTAG);
(void) zfs_unmount_snap(name);
} else {
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, 0);
fnvlist_free(ddura.ddura_todelete);
fnvlist_free(ddura.ddura_chkholds);
return (error);
}
