diff options
Diffstat (limited to 'module/zfs/dsl_dataset.c')
| -rw-r--r-- | module/zfs/dsl_dataset.c | 72 |
1 files changed, 62 insertions, 10 deletions
diff --git a/module/zfs/dsl_dataset.c b/module/zfs/dsl_dataset.c index b04ef69bb..ca0c4aae8 100644 --- a/module/zfs/dsl_dataset.c +++ b/module/zfs/dsl_dataset.c @@ -1669,16 +1669,52 @@ dsl_dataset_rename_snapshot(const char *fsname, dsl_dataset_rename_snapshot_sync, &ddrsa, 1)); } +/* + * If we're doing an ownership handoff, we need to make sure that there is + * only one long hold on the dataset. We're not allowed to change anything here + * so we don't permanently release the long hold or regular hold here. We want + * to do this only when syncing to avoid the dataset unexpectedly going away + * when we release the long hold. + */ +static int +dsl_dataset_handoff_check(dsl_dataset_t *ds, void *owner, dmu_tx_t *tx) +{ + boolean_t held; + + if (!dmu_tx_is_syncing(tx)) + return (0); + + if (owner != NULL) { + VERIFY3P(ds->ds_owner, ==, owner); + dsl_dataset_long_rele(ds, owner); + } + + held = dsl_dataset_long_held(ds); + + if (owner != NULL) + dsl_dataset_long_hold(ds, owner); + + if (held) + return (SET_ERROR(EBUSY)); + + return (0); +} + +typedef struct dsl_dataset_rollback_arg { + const char *ddra_fsname; + void *ddra_owner; +} dsl_dataset_rollback_arg_t; + static int dsl_dataset_rollback_check(void *arg, dmu_tx_t *tx) { - const char *fsname = arg; + dsl_dataset_rollback_arg_t *ddra = arg; dsl_pool_t *dp = dmu_tx_pool(tx); dsl_dataset_t *ds; int64_t unused_refres_delta; int error; - error = dsl_dataset_hold(dp, fsname, FTAG, &ds); + error = dsl_dataset_hold(dp, ddra->ddra_fsname, FTAG, &ds); if (error != 0) return (error); @@ -1694,9 +1730,10 @@ dsl_dataset_rollback_check(void *arg, dmu_tx_t *tx) return (SET_ERROR(EINVAL)); } - if (dsl_dataset_long_held(ds)) { + error = dsl_dataset_handoff_check(ds, ddra->ddra_owner, tx); + if (error != 0) { dsl_dataset_rele(ds, FTAG); - return (SET_ERROR(EBUSY)); + return (error); } /* @@ -1733,12 +1770,12 @@ dsl_dataset_rollback_check(void *arg, dmu_tx_t *tx) static void dsl_dataset_rollback_sync(void *arg, dmu_tx_t *tx) { - const char *fsname = arg; + dsl_dataset_rollback_arg_t *ddra = arg; dsl_pool_t *dp = dmu_tx_pool(tx); dsl_dataset_t *ds, *clone; uint64_t cloneobj; - VERIFY0(dsl_dataset_hold(dp, fsname, FTAG, &ds)); + VERIFY0(dsl_dataset_hold(dp, ddra->ddra_fsname, FTAG, &ds)); cloneobj = dsl_dataset_create_sync(ds->ds_dir, "%rollback", ds->ds_prev, DS_CREATE_FLAG_NODIRTY, kcred, tx); @@ -1754,11 +1791,26 @@ dsl_dataset_rollback_sync(void *arg, dmu_tx_t *tx) dsl_dataset_rele(ds, FTAG); } +/* + * If owner != NULL: + * + * - The existing dataset MUST be owned by the specified owner at entry + * - Upon return, dataset will still be held by the same owner, whether we + * succeed or not. + * + * This mode is required any time the existing filesystem is mounted. See + * notes above zfs_suspend_fs() for further details. + */ int -dsl_dataset_rollback(const char *fsname) +dsl_dataset_rollback(const char *fsname, void *owner) { + dsl_dataset_rollback_arg_t ddra; + + ddra.ddra_fsname = fsname; + ddra.ddra_owner = owner; + return (dsl_sync_task(fsname, dsl_dataset_rollback_check, - dsl_dataset_rollback_sync, (void *)fsname, 1)); + dsl_dataset_rollback_sync, (void *)&ddra, 1)); } struct promotenode { @@ -2276,7 +2328,7 @@ dsl_dataset_promote(const char *name, char *conflsnap) int dsl_dataset_clone_swap_check_impl(dsl_dataset_t *clone, - dsl_dataset_t *origin_head, boolean_t force) + dsl_dataset_t *origin_head, boolean_t force, void *owner, dmu_tx_t *tx) { int64_t unused_refres_delta; @@ -2305,7 +2357,7 @@ dsl_dataset_clone_swap_check_impl(dsl_dataset_t *clone, return (SET_ERROR(ETXTBSY)); /* origin_head should have no long holds (e.g. is not mounted) */ - if (dsl_dataset_long_held(origin_head)) + if (dsl_dataset_handoff_check(origin_head, owner, tx)) return (SET_ERROR(EBUSY)); /* check amount of any unconsumed refreservation */ |