illumos 7004 dmu_tx_hold_zap() does dnode_hold() 7x on same object

include/sys/dmu.h

@@ -20,7 +20,7 @@
  */
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2011, 2014 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2016 by Delphix. All rights reserved.
  * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
  * Copyright (c) 2012, Joyent, Inc. All rights reserved.
  * Copyright 2014 HybridCluster. All rights reserved.
@@ -73,6 +73,7 @@ struct sa_handle;
 typedef struct objset objset_t;
 typedef struct dmu_tx dmu_tx_t;
 typedef struct dsl_dir dsl_dir_t;
+typedef struct dnode dnode_t;
 
 typedef enum dmu_object_byteswap {
 	DMU_BSWAP_UINT8,
@@ -420,7 +421,7 @@ dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset,
 #define	WP_DMU_SYNC	0x2
 #define	WP_SPILL	0x4
 
-void dmu_write_policy(objset_t *os, struct dnode *dn, int level, int wp,
+void dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp,
     struct zio_prop *zp);
 /*
  * The bonus data is accessed more or less like a regular buffer.
@@ -446,7 +447,7 @@ int dmu_rm_spill(objset_t *, uint64_t, dmu_tx_t *);
  */
 
 int dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp);
-int dmu_spill_hold_by_dnode(struct dnode *dn, uint32_t flags,
+int dmu_spill_hold_by_dnode(dnode_t *dn, uint32_t flags,
     void *tag, dmu_buf_t **dbp);
 int dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp);
 
@@ -466,6 +467,8 @@ int dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp);
  */
 int dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
     void *tag, dmu_buf_t **, int flags);
+int dmu_buf_hold_by_dnode(dnode_t *dn, uint64_t offset,
+    void *tag, dmu_buf_t **dbp, int flags);
 
 /*
  * Add a reference to a dmu buffer that has already been held via
@@ -619,6 +622,10 @@ void *dmu_buf_remove_user(dmu_buf_t *db, dmu_buf_user_t *user);
  */
 void *dmu_buf_get_user(dmu_buf_t *db);
 
+objset_t *dmu_buf_get_objset(dmu_buf_t *db);
+dnode_t *dmu_buf_dnode_enter(dmu_buf_t *db);
+void dmu_buf_dnode_exit(dmu_buf_t *db);
+
 /* Block until any in-progress dmu buf user evictions complete. */
 void dmu_buf_user_evict_wait(void);
 
@@ -797,7 +804,7 @@ extern const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS];
 int dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi);
 void __dmu_object_info_from_dnode(struct dnode *dn, dmu_object_info_t *doi);
 /* Like dmu_object_info, but faster if you have a held dnode in hand. */
-void dmu_object_info_from_dnode(struct dnode *dn, dmu_object_info_t *doi);
+void dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi);
 /* Like dmu_object_info, but faster if you have a held dbuf in hand. */
 void dmu_object_info_from_db(dmu_buf_t *db, dmu_object_info_t *doi);
 /*

include/sys/dnode.h

@@ -20,7 +20,7 @@
  */
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
+ * Copyright (c) 2012, 2016 by Delphix. All rights reserved.
  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
  */
 
@@ -181,7 +181,7 @@ typedef struct dnode_phys {
 #define	DN_SPILL_BLKPTR(dnp)	(blkptr_t *)((char *)(dnp) + \
 	(((dnp)->dn_extra_slots + 1) << DNODE_SHIFT) - (1 << SPA_BLKPTRSHIFT))
 
-typedef struct dnode {
+struct dnode {
 	/*
 	 * Protects the structure of the dnode, including the number of levels
 	 * of indirection (dn_nlevels), dn_maxblkid, and dn_next_*
@@ -280,7 +280,7 @@ typedef struct dnode {
 
 	/* holds prefetch structure */
 	struct zfetch	dn_zfetch;
-} dnode_t;
+};
 
 /*
  * Adds a level of indirection between the dbuf and the dnode to avoid

include/sys/zap.h

@@ -236,7 +236,14 @@ int zap_prefetch(objset_t *os, uint64_t zapobj, const char *name);
 int zap_prefetch_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key,
     int key_numints);
 
-int zap_count_write(objset_t *os, uint64_t zapobj, const char *name,
+int zap_lookup_by_dnode(dnode_t *dn, const char *name,
+    uint64_t integer_size, uint64_t num_integers, void *buf);
+int zap_lookup_norm_by_dnode(dnode_t *dn, const char *name,
+    uint64_t integer_size, uint64_t num_integers, void *buf,
+    matchtype_t mt, char *realname, int rn_len,
+    boolean_t *ncp);
+
+int zap_count_write_by_dnode(dnode_t *dn, const char *name,
     int add, uint64_t *towrite, uint64_t *tooverwrite);
 
 /*

include/sys/zap_impl.h

@@ -21,6 +21,7 @@
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
+ * Copyright (c) 2013, 2016 by Delphix. All rights reserved.
  */
 
 #ifndef	_SYS_ZAP_IMPL_H
@@ -195,8 +196,8 @@ typedef struct zap_name {
 
 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);
+    krw_t lti, boolean_t fatreader, boolean_t adding, void *tag, zap_t **zapp);
+void zap_unlockdir(zap_t *zap, void *tag);
 void zap_evict(void *dbu);
 zap_name_t *zap_name_alloc(zap_t *zap, const char *key, matchtype_t mt);
 void zap_name_free(zap_name_t *zn);
@@ -215,9 +216,10 @@ void fzap_prefetch(zap_name_t *zn);
 int fzap_count_write(zap_name_t *zn, int add, uint64_t *towrite,
     uint64_t *tooverwrite);
 int fzap_add(zap_name_t *zn, uint64_t integer_size, uint64_t num_integers,
-    const void *val, dmu_tx_t *tx);
+    const void *val, void *tag, dmu_tx_t *tx);
 int fzap_update(zap_name_t *zn,
-    int integer_size, uint64_t num_integers, const void *val, dmu_tx_t *tx);
+    int integer_size, uint64_t num_integers, const void *val,
+    void *tag, dmu_tx_t *tx);
 int fzap_length(zap_name_t *zn,
     uint64_t *integer_size, uint64_t *num_integers);
 int fzap_remove(zap_name_t *zn, dmu_tx_t *tx);
@@ -227,7 +229,7 @@ void zap_put_leaf(struct zap_leaf *l);
 
 int fzap_add_cd(zap_name_t *zn,
     uint64_t integer_size, uint64_t num_integers,
-    const void *val, uint32_t cd, dmu_tx_t *tx);
+    const void *val, uint32_t cd, void *tag, dmu_tx_t *tx);
 void fzap_upgrade(zap_t *zap, dmu_tx_t *tx, zap_flags_t flags);
 
 #ifdef	__cplusplus

module/zfs/dbuf.c

@@ -21,7 +21,7 @@
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
- * Copyright (c) 2012, 2015 by Delphix. All rights reserved.
+ * Copyright (c) 2012, 2016 by Delphix. All rights reserved.
  * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
  */
@@ -2808,6 +2808,28 @@ dmu_buf_get_blkptr(dmu_buf_t *db)
 	return (dbi->db_blkptr);
 }
 
+objset_t *
+dmu_buf_get_objset(dmu_buf_t *db)
+{
+	dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
+	return (dbi->db_objset);
+}
+
+dnode_t *
+dmu_buf_dnode_enter(dmu_buf_t *db)
+{
+	dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
+	DB_DNODE_ENTER(dbi);
+	return (DB_DNODE(dbi));
+}
+
+void
+dmu_buf_dnode_exit(dmu_buf_t *db)
+{
+	dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
+	DB_DNODE_EXIT(dbi);
+}
+
 static void
 dbuf_check_blkptr(dnode_t *dn, dmu_buf_impl_t *db)
 {

module/zfs/dmu.c

@@ -127,6 +127,26 @@ const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS] = {
 	{	zfs_acl_byteswap,	"acl"		}
 };
 
+int
+dmu_buf_hold_noread_by_dnode(dnode_t *dn, uint64_t offset,
+    void *tag, dmu_buf_t **dbp)
+{
+	uint64_t blkid;
+	dmu_buf_impl_t *db;
+
+	blkid = dbuf_whichblock(dn, 0, offset);
+	rw_enter(&dn->dn_struct_rwlock, RW_READER);
+	db = dbuf_hold(dn, blkid, tag);
+	rw_exit(&dn->dn_struct_rwlock);
+
+	if (db == NULL) {
+		*dbp = NULL;
+		return (SET_ERROR(EIO));
+	}
+
+	*dbp = &db->db;
+	return (0);
+}
 int
 dmu_buf_hold_noread(objset_t *os, uint64_t object, uint64_t offset,
     void *tag, dmu_buf_t **dbp)
@@ -154,6 +174,29 @@ dmu_buf_hold_noread(objset_t *os, uint64_t object, uint64_t offset,
 	return (err);
 }
 
+int
+dmu_buf_hold_by_dnode(dnode_t *dn, uint64_t offset,
+    void *tag, dmu_buf_t **dbp, int flags)
+{
+	int err;
+	int db_flags = DB_RF_CANFAIL;
+
+	if (flags & DMU_READ_NO_PREFETCH)
+		db_flags |= DB_RF_NOPREFETCH;
+
+	err = dmu_buf_hold_noread_by_dnode(dn, offset, tag, dbp);
+	if (err == 0) {
+		dmu_buf_impl_t *db = (dmu_buf_impl_t *)(*dbp);
+		err = dbuf_read(db, NULL, db_flags);
+		if (err != 0) {
+			dbuf_rele(db, tag);
+			*dbp = NULL;
+		}
+	}
+
+	return (err);
+}
+
 int
 dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
     void *tag, dmu_buf_t **dbp, int flags)

module/zfs/dmu_tx.c

@@ -21,7 +21,7 @@
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
- * Copyright (c) 2012, 2015 by Delphix. All rights reserved.
+ * Copyright (c) 2012, 2016 by Delphix. All rights reserved.
  */
 
 #include <sys/dmu.h>
@@ -794,15 +794,14 @@ dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name)
 		 * access the name in this fat-zap so that we'll check
 		 * for i/o errors to the leaf blocks, etc.
 		 */
-		err = zap_lookup(dn->dn_objset, dn->dn_object, name,
-		    8, 0, NULL);
+		err = zap_lookup_by_dnode(dn, name, 8, 0, NULL);
 		if (err == EIO) {
 			tx->tx_err = err;
 			return;
 		}
 	}
 
-	err = zap_count_write(dn->dn_objset, dn->dn_object, name, add,
+	err = zap_count_write_by_dnode(dn, name, add,
 	    &txh->txh_space_towrite, &txh->txh_space_tooverwrite);
 
 	/*