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-rw-r--r--module/zfs/dbuf.c52
-rw-r--r--module/zfs/dnode_sync.c3
-rw-r--r--module/zfs/dsl_dataset.c7
-rw-r--r--module/zfs/dsl_prop.c45
4 files changed, 93 insertions, 14 deletions
diff --git a/module/zfs/dbuf.c b/module/zfs/dbuf.c
index ddfd2e981..cd74ce3e8 100644
--- a/module/zfs/dbuf.c
+++ b/module/zfs/dbuf.c
@@ -149,16 +149,13 @@ dbuf_hash(void *os, uint64_t obj, uint8_t lvl, uint64_t blkid)
(dbuf)->db_blkid == (blkid))
dmu_buf_impl_t *
-dbuf_find(dnode_t *dn, uint8_t level, uint64_t blkid)
+dbuf_find(objset_t *os, uint64_t obj, uint8_t level, uint64_t blkid)
{
dbuf_hash_table_t *h = &dbuf_hash_table;
- objset_t *os = dn->dn_objset;
- uint64_t obj;
uint64_t hv;
uint64_t idx;
dmu_buf_impl_t *db;
- obj = dn->dn_object;
hv = DBUF_HASH(os, obj, level, blkid);
idx = hv & h->hash_table_mask;
@@ -177,6 +174,24 @@ dbuf_find(dnode_t *dn, uint8_t level, uint64_t blkid)
return (NULL);
}
+static dmu_buf_impl_t *
+dbuf_find_bonus(objset_t *os, uint64_t object)
+{
+ dnode_t *dn;
+ dmu_buf_impl_t *db = NULL;
+
+ if (dnode_hold(os, object, FTAG, &dn) == 0) {
+ rw_enter(&dn->dn_struct_rwlock, RW_READER);
+ if (dn->dn_bonus != NULL) {
+ db = dn->dn_bonus;
+ mutex_enter(&db->db_mtx);
+ }
+ rw_exit(&dn->dn_struct_rwlock);
+ dnode_rele(dn, FTAG);
+ }
+ return (db);
+}
+
/*
* Insert an entry into the hash table. If there is already an element
* equal to elem in the hash table, then the already existing element
@@ -2000,7 +2015,7 @@ dbuf_prefetch(dnode_t *dn, uint64_t blkid, zio_priority_t prio)
return;
/* dbuf_find() returns with db_mtx held */
- if ((db = dbuf_find(dn, 0, blkid))) {
+ if ((db = dbuf_find(dn->dn_objset, dn->dn_object, 0, blkid))) {
/*
* This dbuf is already in the cache. We assume that
* it is already CACHED, or else about to be either
@@ -2048,7 +2063,8 @@ __dbuf_hold_impl(struct dbuf_hold_impl_data *dh)
*(dh->dh_dbp) = NULL;
top:
/* dbuf_find() returns with db_mtx held */
- dh->dh_db = dbuf_find(dh->dh_dn, dh->dh_level, dh->dh_blkid);
+ dh->dh_db = dbuf_find(dh->dh_dn->dn_objset, dh->dh_dn->dn_object,
+ dh->dh_level, dh->dh_blkid);
if (dh->dh_db == NULL) {
dh->dh_bp = NULL;
@@ -2228,6 +2244,30 @@ dbuf_add_ref(dmu_buf_impl_t *db, void *tag)
VERIFY(refcount_add(&db->db_holds, tag) > 1);
}
+#pragma weak dmu_buf_try_add_ref = dbuf_try_add_ref
+boolean_t
+dbuf_try_add_ref(dmu_buf_t *db_fake, objset_t *os, uint64_t obj, uint64_t blkid,
+ void *tag)
+{
+ dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
+ dmu_buf_impl_t *found_db;
+ boolean_t result = B_FALSE;
+
+ if (db->db_blkid == DMU_BONUS_BLKID)
+ found_db = dbuf_find_bonus(os, obj);
+ else
+ found_db = dbuf_find(os, obj, 0, blkid);
+
+ if (found_db != NULL) {
+ if (db == found_db && dbuf_refcount(db) > db->db_dirtycnt) {
+ (void) refcount_add(&db->db_holds, tag);
+ result = B_TRUE;
+ }
+ mutex_exit(&db->db_mtx);
+ }
+ return (result);
+}
+
/*
* If you call dbuf_rele() you had better not be referencing the dnode handle
* unless you have some other direct or indirect hold on the dnode. (An indirect
diff --git a/module/zfs/dnode_sync.c b/module/zfs/dnode_sync.c
index cad83a0e0..5c80a531d 100644
--- a/module/zfs/dnode_sync.c
+++ b/module/zfs/dnode_sync.c
@@ -77,7 +77,8 @@ dnode_increase_indirection(dnode_t *dn, dmu_tx_t *tx)
/* set dbuf's parent pointers to new indirect buf */
for (i = 0; i < nblkptr; i++) {
- dmu_buf_impl_t *child = dbuf_find(dn, old_toplvl, i);
+ dmu_buf_impl_t *child =
+ dbuf_find(dn->dn_objset, dn->dn_object, old_toplvl, i);
if (child == NULL)
continue;
diff --git a/module/zfs/dsl_dataset.c b/module/zfs/dsl_dataset.c
index 73b202ceb..a5310edce 100644
--- a/module/zfs/dsl_dataset.c
+++ b/module/zfs/dsl_dataset.c
@@ -351,6 +351,13 @@ dsl_dataset_snap_remove(dsl_dataset_t *ds, const char *name, dmu_tx_t *tx,
return (err);
}
+boolean_t
+dsl_dataset_try_add_ref(dsl_pool_t *dp, dsl_dataset_t *ds, void *tag)
+{
+ return (dmu_buf_try_add_ref(ds->ds_dbuf, dp->dp_meta_objset,
+ ds->ds_object, DMU_BONUS_BLKID, tag));
+}
+
int
dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag,
dsl_dataset_t **dsp)
diff --git a/module/zfs/dsl_prop.c b/module/zfs/dsl_prop.c
index 4c0e57990..69bcd190f 100644
--- a/module/zfs/dsl_prop.c
+++ b/module/zfs/dsl_prop.c
@@ -441,9 +441,31 @@ dsl_prop_notify_all_cb(dsl_pool_t *dp, dsl_dataset_t *ds, void *arg)
cbr = list_next(&dd->dd_prop_cbs, cbr)) {
uint64_t value;
+ /*
+ * Callback entries do not have holds on their datasets
+ * so that datasets with registered callbacks are still
+ * eligible for eviction. Unlike operations on callbacks
+ * for a single dataset, we are performing a recursive
+ * descent of related datasets and the calling context
+ * for this iteration only has a dataset hold on the root.
+ * Without a hold, the callback's pointer to the dataset
+ * could be invalidated by eviction at any time.
+ *
+ * Use dsl_dataset_try_add_ref() to verify that the
+ * dataset has not begun eviction processing and to
+ * prevent eviction from occurring for the duration
+ * of the callback. If the hold attempt fails, this
+ * object is already being evicted and the callback can
+ * be safely ignored.
+ */
+ if (!dsl_dataset_try_add_ref(dp, cbr->cbr_ds, FTAG))
+ continue;
+
if (dsl_prop_get_ds(cbr->cbr_ds, cbr->cbr_propname,
sizeof (value), 1, &value, NULL) == 0)
cbr->cbr_func(cbr->cbr_arg, value);
+
+ dsl_dataset_rele(cbr->cbr_ds, FTAG);
}
mutex_exit(&dd->dd_lock);
@@ -496,19 +518,28 @@ dsl_prop_changed_notify(dsl_pool_t *dp, uint64_t ddobj,
mutex_enter(&dd->dd_lock);
for (cbr = list_head(&dd->dd_prop_cbs); cbr;
cbr = list_next(&dd->dd_prop_cbs, cbr)) {
- uint64_t propobj = dsl_dataset_phys(cbr->cbr_ds)->ds_props_obj;
+ uint64_t propobj;
- if (strcmp(cbr->cbr_propname, propname) != 0)
+ /*
+ * cbr->cbf_ds may be invalidated due to eviction,
+ * requiring the use of dsl_dataset_try_add_ref().
+ * See comment block in dsl_prop_notify_all_cb()
+ * for details.
+ */
+ if (strcmp(cbr->cbr_propname, propname) != 0 ||
+ !dsl_dataset_try_add_ref(dp, cbr->cbr_ds, FTAG))
continue;
+ propobj = dsl_dataset_phys(cbr->cbr_ds)->ds_props_obj;
+
/*
- * If the property is set on this ds, then it is not
- * inherited here; don't call the callback.
+ * If the property is not set on this ds, then it is
+ * inherited here; call the callback.
*/
- if (propobj && 0 == zap_contains(mos, propobj, propname))
- continue;
+ if (propobj == 0 || zap_contains(mos, propobj, propname) != 0)
+ cbr->cbr_func(cbr->cbr_arg, value);
- cbr->cbr_func(cbr->cbr_arg, value);
+ dsl_dataset_rele(cbr->cbr_ds, FTAG);
}
mutex_exit(&dd->dd_lock);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-13 16:09:09 +0000