Fix avl_is_empty(&dn->dn_dbufs) assertion fails in dnode_sync_free

include/sys/dbuf.h

@@ -195,6 +195,14 @@ typedef struct dmu_buf_impl {
 	 */
 	uint8_t db_level;
 
+	/*
+	 * db_user_mtx protects the two members below it.
+	 * stuff we store for the user (see dmu_buf_set_user)
+	 */
+	kmutex_t db_user_mtx;
+	void *db_user_ptr;
+	dmu_buf_evict_func_t *db_evict_func;
+
 	/* db_mtx protects the members below */
 	kmutex_t db_mtx;
 
@@ -227,9 +235,6 @@ typedef struct dmu_buf_impl {
 
 	/* Data which is unique to data (leaf) blocks: */
 
-	/* User callback information. */
-	dmu_buf_user_t *db_user;
-
 	uint8_t db_immediate_evict;
 	uint8_t db_freed_in_flight;
 

include/sys/dmu.h

@@ -40,9 +40,11 @@
  * dmu_spa.h.
  */
 
-#include <sys/zfs_context.h>
 #include <sys/inttypes.h>
+#include <sys/types.h>
+#include <sys/param.h>
 #include <sys/cred.h>
+#include <sys/time.h>
 #include <sys/fs/zfs.h>
 #include <sys/uio.h>
 
@@ -288,6 +290,8 @@ typedef struct dmu_buf {
 	void *db_data;			/* data in buffer */
 } dmu_buf_t;
 
+typedef void dmu_buf_evict_func_t(struct dmu_buf *db, void *user_ptr);
+
 /*
  * The names of zap entries in the DIRECTORY_OBJECT of the MOS.
  */
@@ -489,127 +493,36 @@ int dmu_buf_hold_array_by_bonus(dmu_buf_t *db, uint64_t offset,
     uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp);
 void dmu_buf_rele_array(dmu_buf_t **, int numbufs, void *tag);
 
-typedef void dmu_buf_evict_func_t(void *user_ptr);
-
-/*
- * A DMU buffer user object may be associated with a dbuf for the
- * duration of its lifetime.  This allows the user of a dbuf (client)
- * to attach private data to a dbuf (e.g. in-core only data such as a
- * dnode_children_t, zap_t, or zap_leaf_t) and be optionally notified
- * when that dbuf has been evicted.  Clients typically respond to the
- * eviction notification by freeing their private data, thus ensuring
- * the same lifetime for both dbuf and private data.
- *
- * The mapping from a dmu_buf_user_t to any client private data is the
- * client's responsibility.  All current consumers of the API with private
- * data embed a dmu_buf_user_t as the first member of the structure for
- * their private data.  This allows conversions between the two types
- * with a simple cast.  Since the DMU buf user API never needs access
- * to the private data, other strategies can be employed if necessary
- * or convenient for the client (e.g. using container_of() to do the
- * conversion for private data that cannot have the dmu_buf_user_t as
- * its first member).
- *
- * Eviction callbacks are executed without the dbuf mutex held or any
- * other type of mechanism to guarantee that the dbuf is still available.
- * For this reason, users must assume the dbuf has already been freed
- * and not reference the dbuf from the callback context.
- *
- * Users requesting "immediate eviction" are notified as soon as the dbuf
- * is only referenced by dirty records (dirties == holds).  Otherwise the
- * notification occurs after eviction processing for the dbuf begins.
- */
-typedef struct dmu_buf_user {
-	/*
-	 * Asynchronous user eviction callback state.
-	 */
-	taskq_ent_t	dbu_tqent;
-
-	/* This instance's eviction function pointer. */
-	dmu_buf_evict_func_t *dbu_evict_func;
-#ifdef ZFS_DEBUG
-	/*
-	 * Pointer to user's dbuf pointer.  NULL for clients that do
-	 * not associate a dbuf with their user data.
-	 *
-	 * The dbuf pointer is cleared upon eviction so as to catch
-	 * use-after-evict bugs in clients.
-	 */
-	dmu_buf_t **dbu_clear_on_evict_dbufp;
-#endif
-} dmu_buf_user_t;
-
-/*
- * Initialize the given dmu_buf_user_t instance with the eviction function
- * evict_func, to be called when the user is evicted.
- *
- * NOTE: This function should only be called once on a given dmu_buf_user_t.
- *       To allow enforcement of this, dbu must already be zeroed on entry.
- */
-#ifdef __lint
-/* Very ugly, but it beats issuing suppression directives in many Makefiles. */
-extern void
-dmu_buf_init_user(dmu_buf_user_t *dbu, dmu_buf_evict_func_t *evict_func,
-    dmu_buf_t **clear_on_evict_dbufp);
-#else /* __lint */
-static inline void
-dmu_buf_init_user(dmu_buf_user_t *dbu, dmu_buf_evict_func_t *evict_func,
-    dmu_buf_t **clear_on_evict_dbufp)
-{
-	ASSERT(dbu->dbu_evict_func == NULL);
-	ASSERT(evict_func != NULL);
-	dbu->dbu_evict_func = evict_func;
-	taskq_init_ent(&dbu->dbu_tqent);
-#ifdef ZFS_DEBUG
-	dbu->dbu_clear_on_evict_dbufp = clear_on_evict_dbufp;
-#endif
-}
-#endif /* __lint */
-
 /*
- * Attach user data to a dbuf and mark it for normal (when the dbuf's
- * data is cleared or its reference count goes to zero) eviction processing.
+ * Returns NULL on success, or the existing user ptr if it's already
+ * been set.
  *
- * Returns NULL on success, or the existing user if another user currently
- * owns the buffer.
- */
-void *dmu_buf_set_user(dmu_buf_t *db, dmu_buf_user_t *user);
-
-/*
- * Attach user data to a dbuf and mark it for immediate (its dirty and
- * reference counts are equal) eviction processing.
+ * user_ptr is for use by the user and can be obtained via dmu_buf_get_user().
  *
- * Returns NULL on success, or the existing user if another user currently
- * owns the buffer.
- */
-void *dmu_buf_set_user_ie(dmu_buf_t *db, dmu_buf_user_t *user);
-
-/*
- * Replace the current user of a dbuf.
+ * If non-NULL, pageout func will be called when this buffer is being
+ * excised from the cache, so that you can clean up the data structure
+ * pointed to by user_ptr.
  *
- * If given the current user of a dbuf, replaces the dbuf's user with
- * "new_user" and returns the user data pointer that was replaced.
- * Otherwise returns the current, and unmodified, dbuf user pointer.
+ * dmu_evict_user() will call the pageout func for all buffers in a
+ * objset with a given pageout func.
  */
-void *dmu_buf_replace_user(dmu_buf_t *db,
-    dmu_buf_user_t *old_user, dmu_buf_user_t *new_user);
-
+void *dmu_buf_set_user(dmu_buf_t *db, void *user_ptr,
+    dmu_buf_evict_func_t *pageout_func);
 /*
- * Remove the specified user data for a DMU buffer.
- *
- * Returns the user that was removed on success, or the current user if
- * another user currently owns the buffer.
+ * set_user_ie is the same as set_user, but request immediate eviction
+ * when hold count goes to zero.
  */
-void *dmu_buf_remove_user(dmu_buf_t *db, dmu_buf_user_t *user);
+void *dmu_buf_set_user_ie(dmu_buf_t *db, void *user_ptr,
+    dmu_buf_evict_func_t *pageout_func);
+void *dmu_buf_update_user(dmu_buf_t *db_fake, void *old_user_ptr,
+    void *user_ptr, dmu_buf_evict_func_t *pageout_func);
+void dmu_evict_user(objset_t *os, dmu_buf_evict_func_t *func);
 
 /*
- * Returns the user data (dmu_buf_user_t *) associated with this dbuf.
+ * Returns the user_ptr set with dmu_buf_set_user(), or NULL if not set.
  */
 void *dmu_buf_get_user(dmu_buf_t *db);
 
-/* Block until any in-progress dmu buf user evictions complete. */
-void dmu_buf_user_evict_wait(void);
-
 /*
  * Returns the blkptr associated with this dbuf, or NULL if not set.
  */

include/sys/dmu_objset.h

@@ -75,25 +75,22 @@ struct objset {
 	arc_buf_t *os_phys_buf;
 	objset_phys_t *os_phys;
 	/*
-	 * The following "special" dnodes have no parent, are exempt
-	 * from dnode_move(), and are not recorded in os_dnodes, but they
-	 * root their descendents in this objset using handles anyway, so
-	 * that all access to dnodes from dbufs consistently uses handles.
+	 * The following "special" dnodes have no parent and are exempt from
+	 * dnode_move(), but they root their descendents in this objset using
+	 * handles anyway, so that all access to dnodes from dbufs consistently
+	 * uses handles.
 	 */
 	dnode_handle_t os_meta_dnode;
 	dnode_handle_t os_userused_dnode;
 	dnode_handle_t os_groupused_dnode;
 	zilog_t *os_zil;
 
-	list_node_t os_evicting_node;
-
 	/* can change, under dsl_dir's locks: */
 	enum zio_checksum os_checksum;
 	enum zio_compress os_compress;
 	uint8_t os_copies;
 	enum zio_checksum os_dedup_checksum;
 	boolean_t os_dedup_verify;
-	boolean_t os_evicting;
 	zfs_logbias_op_t os_logbias;
 	zfs_cache_type_t os_primary_cache;
 	zfs_cache_type_t os_secondary_cache;
@@ -175,8 +172,6 @@ int dmu_objset_userspace_upgrade(objset_t *os);
 boolean_t dmu_objset_userspace_present(objset_t *os);
 int dmu_fsname(const char *snapname, char *buf);
 
-void dmu_objset_evict_done(objset_t *os);
-
 void dmu_objset_init(void);
 void dmu_objset_fini(void);
 

include/sys/dnode.h

@@ -278,7 +278,6 @@ typedef struct dnode_handle {
 } dnode_handle_t;
 
 typedef struct dnode_children {
-	dmu_buf_user_t dnc_dbu;		/* User evict data */
 	size_t dnc_count;		/* number of children */
 	dnode_handle_t dnc_children[];	/* sized dynamically */
 } dnode_children_t;
@@ -289,7 +288,7 @@ typedef struct free_range {
 	uint64_t fr_nblks;
 } free_range_t;
 
-void dnode_special_open(struct objset *dd, dnode_phys_t *dnp,
+dnode_t *dnode_special_open(struct objset *dd, dnode_phys_t *dnp,
     uint64_t object, dnode_handle_t *dnh);
 void dnode_special_close(dnode_handle_t *dnh);
 

include/sys/dsl_dataset.h

@@ -133,14 +133,11 @@ typedef struct dsl_dataset_phys {
 } dsl_dataset_phys_t;
 
 typedef struct dsl_dataset {
-	dmu_buf_user_t ds_dbu;
-
 	/* Immutable: */
 	struct dsl_dir *ds_dir;
 	dmu_buf_t *ds_dbuf;
 	uint64_t ds_object;
 	uint64_t ds_fsid_guid;
-	boolean_t ds_is_snapshot;
 
 	/* only used in syncing context, only valid for non-snapshots: */
 	struct dsl_dataset *ds_prev;
@@ -201,8 +198,11 @@ dsl_dataset_phys(dsl_dataset_t *ds)
  */
 #define	MAX_TAG_PREFIX_LEN	17
 
-#define	dsl_dataset_is_snapshot(ds) \
-	(dsl_dataset_phys(ds)->ds_num_children != 0)
+static inline boolean_t
+dsl_dataset_is_snapshot(dsl_dataset_t *ds)
+{
+	return (dsl_dataset_phys(ds)->ds_num_children != 0);
+}
 
 #define	DS_UNIQUE_IS_ACCURATE(ds)	\
 	((dsl_dataset_phys(ds)->ds_flags & DS_FLAG_UNIQUE_ACCURATE) != 0)

include/sys/dsl_dir.h

@@ -85,8 +85,6 @@ typedef struct dsl_dir_phys {
 } dsl_dir_phys_t;
 
 struct dsl_dir {
-	dmu_buf_user_t dd_dbu;
-
 	/* These are immutable; no lock needed: */
 	uint64_t dd_object;
 	dsl_pool_t *dd_pool;
@@ -122,7 +120,6 @@ dsl_dir_phys(dsl_dir_t *dd)
 }
 
 void dsl_dir_rele(dsl_dir_t *dd, void *tag);
-void dsl_dir_async_rele(dsl_dir_t *dd, void *tag);
 int dsl_dir_hold(dsl_pool_t *dp, const char *name, void *tag,
     dsl_dir_t **, const char **tail);
 int dsl_dir_hold_obj(dsl_pool_t *dp, uint64_t ddobj,

include/sys/sa.h

@@ -133,6 +133,7 @@ int sa_update_from_cb(sa_handle_t *, sa_attr_type_t,
     uint32_t buflen, sa_data_locator_t *, void *userdata, dmu_tx_t *);
 void sa_object_info(sa_handle_t *, dmu_object_info_t *);
 void sa_object_size(sa_handle_t *, uint32_t *, u_longlong_t *);
+void sa_update_user(sa_handle_t *, sa_handle_t *);
 void *sa_get_userdata(sa_handle_t *);
 void sa_set_userp(sa_handle_t *, void *);
 dmu_buf_t *sa_get_db(sa_handle_t *);

include/sys/sa_impl.h

@@ -209,12 +209,11 @@ typedef enum sa_data_op {
  */
 
 struct sa_handle {
-	dmu_buf_user_t	sa_dbu;
 	kmutex_t	sa_lock;
 	dmu_buf_t	*sa_bonus;
 	dmu_buf_t	*sa_spill;
 	objset_t	*sa_os;
-	void		*sa_userp;
+	void 		*sa_userp;
 	sa_idx_tab_t	*sa_bonus_tab;	 /* idx of bonus */
 	sa_idx_tab_t	*sa_spill_tab; /* only present if spill activated */
 };

include/sys/spa.h

@@ -690,7 +690,6 @@ extern spa_t *spa_next(spa_t *prev);
 /* Refcount functions */
 extern void spa_open_ref(spa_t *spa, void *tag);
 extern void spa_close(spa_t *spa, void *tag);
-extern void spa_async_close(spa_t *spa, void *tag);
 extern boolean_t spa_refcount_zero(spa_t *spa);
 
 #define	SCL_NONE	0x00
@@ -801,9 +800,6 @@ extern uint64_t spa_version(spa_t *spa);
 extern boolean_t spa_deflate(spa_t *spa);
 extern metaslab_class_t *spa_normal_class(spa_t *spa);
 extern metaslab_class_t *spa_log_class(spa_t *spa);
-extern void spa_evicting_os_register(spa_t *, objset_t *os);
-extern void spa_evicting_os_deregister(spa_t *, objset_t *os);
-extern void spa_evicting_os_wait(spa_t *spa);
 extern int spa_max_replication(spa_t *spa);
 extern int spa_prev_software_version(spa_t *spa);
 extern uint8_t spa_get_failmode(spa_t *spa);

include/sys/spa_impl.h

@@ -145,9 +145,6 @@ struct spa {
 	uint64_t	spa_claim_max_txg;	/* highest claimed birth txg */
 	timespec_t	spa_loaded_ts;		/* 1st successful open time */
 	objset_t	*spa_meta_objset;	/* copy of dp->dp_meta_objset */
-	kmutex_t	spa_evicting_os_lock;	/* Evicting objset list lock */
-	list_t		spa_evicting_os_list;	/* Objsets being evicted. */
-	kcondvar_t	spa_evicting_os_cv;	/* Objset Eviction Completion */
 	txg_list_t	spa_vdev_txg_list;	/* per-txg dirty vdev list */
 	vdev_t		*spa_root_vdev;		/* top-level vdev container */
 	int		spa_min_ashift;		/* of vdevs in normal class */

include/sys/zap_impl.h

@@ -140,7 +140,6 @@ typedef struct zap_phys {
 typedef struct zap_table_phys zap_table_phys_t;
 
 typedef struct zap {
-	dmu_buf_user_t zap_dbu;
 	objset_t *zap_objset;
 	uint64_t zap_object;
 	struct dmu_buf *zap_dbuf;
@@ -197,7 +196,7 @@ boolean_t zap_match(zap_name_t *zn, const char *matchname);
 int zap_lockdir(objset_t *os, uint64_t obj, dmu_tx_t *tx,
     krw_t lti, boolean_t fatreader, boolean_t adding, zap_t **zapp);
 void zap_unlockdir(zap_t *zap);
-void zap_evict(void *dbu);
+void zap_evict(dmu_buf_t *db, void *vmzap);
 zap_name_t *zap_name_alloc(zap_t *zap, const char *key, matchtype_t mt);
 void zap_name_free(zap_name_t *zn);
 int zap_hashbits(zap_t *zap);

include/sys/zap_leaf.h

@@ -153,7 +153,6 @@ typedef union zap_leaf_chunk {
 } zap_leaf_chunk_t;
 
 typedef struct zap_leaf {
-	dmu_buf_user_t l_dbu;
 	krwlock_t l_rwlock;
 	uint64_t l_blkid;		/* 1<<ZAP_BLOCK_SHIFT byte block off */
 	int l_bs;			/* block size shift */