From ed82dc5c7f4b662c6b1739c1dad317d49daf6250 Mon Sep 17 00:00:00 2001
From: Sanjeev Bagewadi <sanjeev.bagewadi@nutanix.com>
Date: Fri, 18 Jun 2021 08:55:01 +0000
Subject: [PATCH] Support for longnames for files/directories (Linux part)

This patch adds the ability for zfs to support file/dir name up to 1023
bytes. This number is chosen so we can support up to 255 4-byte
characters. This new feature is represented by the new feature flag
feature@longname.

A new dataset property "longname" is also introduced to toggle longname
support for each dataset individually. This property can be disabled,
even if it contains longname files. In such case, new file cannot be
created with longname but existing longname files can still be looked
up.

Note that, to my knowledge native Linux filesystems don't support name
longer than 255 bytes. So there might be programs not able to work with
longname.

Note that NFS server may needs to use exportfs_get_name to reconnect
dentries, and the buffer being passed is limit to NAME_MAX+1 (256). So
NFS may not work when longname is enabled.

Signed-off-by: Chunwei Chen <david.chen@nutanix.com>
---
 cmd/zdb/zdb.c                                 |   4 +-
 cmd/zhack.c                                   |   2 +-
 include/os/linux/zfs/sys/zfs_vfsops_os.h      |   1 +
 include/os/linux/zfs/sys/zfs_vnops_os.h       |   1 +
 include/sys/fs/zfs.h                          |   2 +
 include/sys/zap.h                             |   3 +-
 include/sys/zfs_ioctl.h                       |   4 +-
 include/zfeature_common.h                     |   1 +
 lib/libzfs/libzfs.abi                         | 653 ++++++++----------
 module/os/freebsd/zfs/zfs_znode_os.c          |   2 +-
 module/os/linux/zfs/zfs_dir.c                 |   9 +
 module/os/linux/zfs/zfs_vfsops.c              |  12 +-
 module/os/linux/zfs/zfs_vnops_os.c            |  42 +-
 module/os/linux/zfs/zpl_export.c              |  31 +
 module/os/linux/zfs/zpl_inode.c               |  56 +-
 module/zcommon/zfeature_common.c              |  12 +
 module/zcommon/zfs_prop.c                     |   4 +
 module/zfs/dmu_recv.c                         |  17 +
 module/zfs/dmu_send.c                         |   4 +
 module/zfs/dsl_dataset.c                      |   3 +-
 module/zfs/dsl_dir.c                          |   3 +-
 module/zfs/zap.c                              |  20 +-
 module/zfs/zap_micro.c                        |  96 ++-
 module/zfs/zfs_ioctl.c                        |  35 +
 module/zfs/zfs_znode.c                        |   8 +-
 tests/runfiles/linux.run                      |   6 +-
 tests/zfs-tests/tests/Makefile.am             |   6 +
 .../cli_root/zpool_get/zpool_get.cfg          |   1 +
 .../tests/functional/longname/cleanup.ksh     |  34 +
 .../functional/longname/longname_001_pos.ksh  | 132 ++++
 .../functional/longname/longname_002_pos.ksh  | 115 +++
 .../functional/longname/longname_003_pos.ksh  | 113 +++
 .../tests/functional/longname/setup.ksh       |  35 +
 .../tests/functional/rsend/rsend.kshlib       |   1 +
 .../functional/rsend/send-c_longname.ksh      |  98 +++
 35 files changed, 1164 insertions(+), 402 deletions(-)
 create mode 100755 tests/zfs-tests/tests/functional/longname/cleanup.ksh
 create mode 100755 tests/zfs-tests/tests/functional/longname/longname_001_pos.ksh
 create mode 100755 tests/zfs-tests/tests/functional/longname/longname_002_pos.ksh
 create mode 100755 tests/zfs-tests/tests/functional/longname/longname_003_pos.ksh
 create mode 100755 tests/zfs-tests/tests/functional/longname/setup.ksh
 create mode 100755 tests/zfs-tests/tests/functional/rsend/send-c_longname.ksh

diff --git a/cmd/zdb/zdb.c b/cmd/zdb/zdb.c
index 83f79ad65613..f185e24601cb 100644
--- a/cmd/zdb/zdb.c
+++ b/cmd/zdb/zdb.c
@@ -1117,7 +1117,7 @@ dump_zap(objset_t *os, uint64_t object, void *data, size_t size)
 {
 	(void) data, (void) size;
 	zap_cursor_t zc;
-	zap_attribute_t *attrp = zap_attribute_alloc();
+	zap_attribute_t *attrp = zap_attribute_long_alloc();
 	void *prop;
 	unsigned i;
 
@@ -1365,7 +1365,7 @@ dump_zpldir(objset_t *os, uint64_t object, void *data, size_t size)
 {
 	(void) data, (void) size;
 	zap_cursor_t zc;
-	zap_attribute_t *attrp = zap_attribute_alloc();
+	zap_attribute_t *attrp = zap_attribute_long_alloc();
 	const char *typenames[] = {
 		/* 0 */ "not specified",
 		/* 1 */ "FIFO",
diff --git a/cmd/zhack.c b/cmd/zhack.c
index 77284b8955ed..f297afb65d47 100644
--- a/cmd/zhack.c
+++ b/cmd/zhack.c
@@ -203,7 +203,7 @@ static void
 dump_obj(objset_t *os, uint64_t obj, const char *name)
 {
 	zap_cursor_t zc;
-	zap_attribute_t *za = zap_attribute_alloc();
+	zap_attribute_t *za = zap_attribute_long_alloc();
 
 	(void) printf("%s_obj:\n", name);
 
diff --git a/include/os/linux/zfs/sys/zfs_vfsops_os.h b/include/os/linux/zfs/sys/zfs_vfsops_os.h
index b4d5db21f5e5..e742e8dc392e 100644
--- a/include/os/linux/zfs/sys/zfs_vfsops_os.h
+++ b/include/os/linux/zfs/sys/zfs_vfsops_os.h
@@ -118,6 +118,7 @@ struct zfsvfs {
 	boolean_t	z_xattr_sa;	/* allow xattrs to be stores as SA */
 	boolean_t	z_draining;	/* is true when drain is active */
 	boolean_t	z_drain_cancel; /* signal the unlinked drain to stop */
+	boolean_t	z_longname;	/* Dataset supports long names */
 	uint64_t	z_version;	/* ZPL version */
 	uint64_t	z_shares_dir;	/* hidden shares dir */
 	dataset_kstats_t	z_kstat;	/* fs kstats */
diff --git a/include/os/linux/zfs/sys/zfs_vnops_os.h b/include/os/linux/zfs/sys/zfs_vnops_os.h
index f34eb153f546..db33eda57705 100644
--- a/include/os/linux/zfs/sys/zfs_vnops_os.h
+++ b/include/os/linux/zfs/sys/zfs_vnops_os.h
@@ -44,6 +44,7 @@ extern int zfs_write_simple(znode_t *zp, const void *data, size_t len,
     loff_t pos, size_t *resid);
 extern int zfs_lookup(znode_t *dzp, char *nm, znode_t **zpp, int flags,
     cred_t *cr, int *direntflags, pathname_t *realpnp);
+extern int zfs_get_name(znode_t *dzp, char *name, znode_t *zp);
 extern int zfs_create(znode_t *dzp, char *name, vattr_t *vap, int excl,
     int mode, znode_t **zpp, cred_t *cr, int flag, vsecattr_t *vsecp,
     zidmap_t *mnt_ns);
diff --git a/include/sys/fs/zfs.h b/include/sys/fs/zfs.h
index 3852fa03173c..cd2496bf7e95 100644
--- a/include/sys/fs/zfs.h
+++ b/include/sys/fs/zfs.h
@@ -81,6 +81,7 @@ typedef enum dmu_objset_type {
  * All of these include the terminating NUL byte.
  */
 #define	ZAP_MAXNAMELEN 256
+#define	ZAP_MAXNAMELEN_NEW 1024
 #define	ZAP_MAXVALUELEN (1024 * 8)
 #define	ZAP_OLDMAXVALUELEN 1024
 #define	ZFS_MAX_DATASET_NAME_LEN 256
@@ -194,6 +195,7 @@ typedef enum {
 	ZFS_PROP_PREFETCH,
 	ZFS_PROP_VOLTHREADING,
 	ZFS_PROP_DIRECT,
+	ZFS_PROP_LONGNAME,
 	ZFS_NUM_PROPS
 } zfs_prop_t;
 
diff --git a/include/sys/zap.h b/include/sys/zap.h
index ec37c3447182..43e8bbea1991 100644
--- a/include/sys/zap.h
+++ b/include/sys/zap.h
@@ -315,7 +315,7 @@ int zap_count(objset_t *ds, uint64_t zapobj, uint64_t *count);
  * match must be exact (ie, same as mask=-1ULL).
  */
 int zap_value_search(objset_t *os, uint64_t zapobj,
-    uint64_t value, uint64_t mask, char *name);
+    uint64_t value, uint64_t mask, char *name, uint64_t namelen);
 
 /*
  * Transfer all the entries from fromobj into intoobj.  Only works on
@@ -387,6 +387,7 @@ void zap_fini(void);
  * Alloc and free zap_attribute_t.
  */
 zap_attribute_t *zap_attribute_alloc(void);
+zap_attribute_t *zap_attribute_long_alloc(void);
 void zap_attribute_free(zap_attribute_t *attrp);
 
 /*
diff --git a/include/sys/zfs_ioctl.h b/include/sys/zfs_ioctl.h
index 525d40759fdd..d177472016ec 100644
--- a/include/sys/zfs_ioctl.h
+++ b/include/sys/zfs_ioctl.h
@@ -124,7 +124,7 @@ typedef enum drr_headertype {
  * default use of "zfs send" won't encounter the bug mentioned above.
  */
 #define	DMU_BACKUP_FEATURE_SWITCH_TO_LARGE_BLOCKS (1 << 27)
-/* flag #28 is reserved for a Nutanix feature */
+#define	DMU_BACKUP_FEATURE_LONGNAME		(1 << 28)
 /*
  * flag #29 is the last unused bit. It is reserved to indicate a to-be-designed
  * extension to the stream format which will accomodate more feature flags.
@@ -141,7 +141,7 @@ typedef enum drr_headertype {
     DMU_BACKUP_FEATURE_COMPRESSED | DMU_BACKUP_FEATURE_LARGE_DNODE | \
     DMU_BACKUP_FEATURE_RAW | DMU_BACKUP_FEATURE_HOLDS | \
     DMU_BACKUP_FEATURE_REDACTED | DMU_BACKUP_FEATURE_SWITCH_TO_LARGE_BLOCKS | \
-    DMU_BACKUP_FEATURE_ZSTD)
+    DMU_BACKUP_FEATURE_ZSTD | DMU_BACKUP_FEATURE_LONGNAME)
 
 /* Are all features in the given flag word currently supported? */
 #define	DMU_STREAM_SUPPORTED(x)	(!((x) & ~DMU_BACKUP_FEATURE_MASK))
diff --git a/include/zfeature_common.h b/include/zfeature_common.h
index 5733a8187a95..1ca122d30ef5 100644
--- a/include/zfeature_common.h
+++ b/include/zfeature_common.h
@@ -83,6 +83,7 @@ typedef enum spa_feature {
 	SPA_FEATURE_REDACTION_LIST_SPILL,
 	SPA_FEATURE_RAIDZ_EXPANSION,
 	SPA_FEATURE_FAST_DEDUP,
+	SPA_FEATURE_LONGNAME,
 	SPA_FEATURES
 } spa_feature_t;
 
diff --git a/lib/libzfs/libzfs.abi b/lib/libzfs/libzfs.abi
index 1f1f2fdffb15..1bbbc5dd547c 100644
--- a/lib/libzfs/libzfs.abi
+++ b/lib/libzfs/libzfs.abi
@@ -2,7 +2,6 @@
   <elf-needed>
     <dependency name='libzfs_core.so.3'/>
     <dependency name='libnvpair.so.3'/>
-    <dependency name='libtirpc.so.3'/>
     <dependency name='libuuid.so.1'/>
     <dependency name='libblkid.so.1'/>
     <dependency name='libudev.so.1'/>
@@ -629,7 +628,7 @@
     <elf-symbol name='fletcher_4_superscalar_ops' size='128' type='object-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='libzfs_config_ops' size='16' type='object-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='sa_protocol_names' size='16' type='object-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
-    <elf-symbol name='spa_feature_table' size='2352' type='object-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
+    <elf-symbol name='spa_feature_table' size='2408' type='object-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zfeature_checks_disable' size='4' type='object-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zfs_deleg_perm_tab' size='512' type='object-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='zfs_history_event_names' size='328' type='object-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
@@ -765,25 +764,6 @@
       <parameter type-id='80f4b756'/>
       <return type-id='48b5725f'/>
     </function-decl>
-    <function-decl name='bsearch' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='eaa32e2f'/>
-      <parameter type-id='eaa32e2f'/>
-      <parameter type-id='b59d7dce'/>
-      <parameter type-id='b59d7dce'/>
-      <parameter type-id='aba7edd8'/>
-      <return type-id='eaa32e2f'/>
-    </function-decl>
-    <function-decl name='memmove' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='eaa32e2f'/>
-      <parameter type-id='eaa32e2f'/>
-      <parameter type-id='b59d7dce'/>
-      <return type-id='eaa32e2f'/>
-    </function-decl>
-    <function-decl name='strcat' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='26a90f95'/>
-      <parameter type-id='80f4b756'/>
-      <return type-id='26a90f95'/>
-    </function-decl>
     <function-type size-in-bits='64' id='276427e1'>
       <return type-id='95e97e5e'/>
     </function-type>
@@ -810,8 +790,9 @@
   </abi-instr>
   <abi-instr address-size='64' path='lib/libshare/os/linux/smb.c' language='LANG_C99'>
     <var-decl name='libshare_smb_type' type-id='d19dbca9' visibility='default'/>
-    <function-decl name='fgets' visibility='default' binding='global' size-in-bits='64'>
+    <function-decl name='__fgets_chk' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='266fe297'/>
+      <parameter type-id='b59d7dce'/>
       <parameter type-id='95e97e5e'/>
       <parameter type-id='e75a27e9'/>
       <return type-id='26a90f95'/>
@@ -825,12 +806,6 @@
     <function-decl name='gettid' visibility='default' binding='global' size-in-bits='64'>
       <return type-id='3629bad8'/>
     </function-decl>
-    <function-decl name='vfprintf' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='e75a27e9'/>
-      <parameter type-id='9d26089a'/>
-      <parameter type-id='b7f2d5e6'/>
-      <return type-id='95e97e5e'/>
-    </function-decl>
     <function-decl name='prctl' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='95e97e5e'/>
       <parameter is-variadic='yes'/>
@@ -1288,16 +1263,18 @@
     <qualified-type-def type-id='f077d3f8' restrict='yes' id='598aab80'/>
     <pointer-type-def type-id='928221d2' size-in-bits='64' id='323d93c1'/>
     <qualified-type-def type-id='323d93c1' restrict='yes' id='f1358bc3'/>
-    <function-decl name='mbstowcs' visibility='default' binding='global' size-in-bits='64'>
+    <function-decl name='__mbstowcs_chk' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='f1358bc3'/>
       <parameter type-id='9d26089a'/>
       <parameter type-id='b59d7dce'/>
+      <parameter type-id='b59d7dce'/>
       <return type-id='b59d7dce'/>
     </function-decl>
-    <function-decl name='wcstombs' visibility='default' binding='global' size-in-bits='64'>
+    <function-decl name='__wcstombs_chk' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='266fe297'/>
       <parameter type-id='598aab80'/>
       <parameter type-id='b59d7dce'/>
+      <parameter type-id='b59d7dce'/>
       <return type-id='b59d7dce'/>
     </function-decl>
   </abi-instr>
@@ -1315,19 +1292,6 @@
       <parameter type-id='822cd80b'/>
       <return type-id='95e97e5e'/>
     </function-decl>
-    <function-decl name='gnu_dev_major' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='35ed8932'/>
-      <return type-id='f0981eeb'/>
-    </function-decl>
-    <function-decl name='gnu_dev_minor' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='35ed8932'/>
-      <return type-id='f0981eeb'/>
-    </function-decl>
-    <function-decl name='gnu_dev_makedev' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='f0981eeb'/>
-      <parameter type-id='f0981eeb'/>
-      <return type-id='35ed8932'/>
-    </function-decl>
   </abi-instr>
   <abi-instr address-size='64' path='lib/libspl/timestamp.c' language='LANG_C99'>
     <typedef-decl name='nl_item' type-id='95e97e5e' id='03b79a94'/>
@@ -1476,10 +1440,6 @@
     <pointer-type-def type-id='6fcda10e' size-in-bits='64' id='ad33e5e7'/>
     <pointer-type-def type-id='66a0afc9' size-in-bits='64' id='f32b30e4'/>
     <qualified-type-def type-id='63e171df' restrict='yes' id='9e7a3a7d'/>
-    <function-decl name='__sysconf' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='95e97e5e'/>
-      <return type-id='bd54fe1a'/>
-    </function-decl>
     <function-decl name='pthread_self' visibility='default' binding='global' size-in-bits='64'>
       <return type-id='4051f5e7'/>
     </function-decl>
@@ -1613,6 +1573,10 @@
       <parameter type-id='0be2e71c'/>
       <return type-id='95e97e5e'/>
     </function-decl>
+    <function-decl name='__sysconf' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='95e97e5e'/>
+      <return type-id='bd54fe1a'/>
+    </function-decl>
     <function-decl name='tpool_abandon' mangled-name='tpool_abandon' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='tpool_abandon'>
       <parameter type-id='9cf59a50' name='tpool'/>
       <return type-id='48b5725f'/>
@@ -1725,7 +1689,6 @@
     <type-decl name='unsigned char' size-in-bits='8' id='002ac4a6'/>
     <type-decl name='unsigned int' size-in-bits='32' id='f0981eeb'/>
     <type-decl name='unsigned long int' size-in-bits='64' id='7359adad'/>
-    <type-decl name='variadic parameter type' id='2c1145c5'/>
     <type-decl name='void' id='48b5725f'/>
     <typedef-decl name='uu_compare_fn_t' type-id='add6e811' id='40f93560'/>
     <typedef-decl name='uu_avl_pool_t' type-id='12a530a8' id='7f84e390'/>
@@ -1921,7 +1884,8 @@
       <enumerator name='ZFS_PROP_PREFETCH' value='96'/>
       <enumerator name='ZFS_PROP_VOLTHREADING' value='97'/>
       <enumerator name='ZFS_PROP_DIRECT' value='98'/>
-      <enumerator name='ZFS_NUM_PROPS' value='99'/>
+      <enumerator name='ZFS_PROP_LONGNAME' value='99'/>
+      <enumerator name='ZFS_NUM_PROPS' value='100'/>
     </enum-decl>
     <typedef-decl name='zfs_prop_t' type-id='4b000d60' id='58603c44'/>
     <enum-decl name='zprop_source_t' naming-typedef-id='a2256d42' id='5903f80e'>
@@ -1969,6 +1933,54 @@
     <typedef-decl name='longlong_t' type-id='1eb56b1e' id='9b3ff54f'/>
     <typedef-decl name='diskaddr_t' type-id='9b3ff54f' id='804dc465'/>
     <typedef-decl name='zoneid_t' type-id='3502e3ff' id='4da03624'/>
+    <typedef-decl name='__re_long_size_t' type-id='7359adad' id='ba516949'/>
+    <typedef-decl name='reg_syntax_t' type-id='7359adad' id='1b72c3b3'/>
+    <class-decl name='re_pattern_buffer' size-in-bits='512' is-struct='yes' visibility='default' id='19fc9a8c'>
+      <data-member access='public' layout-offset-in-bits='0'>
+        <var-decl name='buffer' type-id='33976309' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='64'>
+        <var-decl name='allocated' type-id='ba516949' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='128'>
+        <var-decl name='used' type-id='ba516949' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='192'>
+        <var-decl name='syntax' type-id='1b72c3b3' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='256'>
+        <var-decl name='fastmap' type-id='26a90f95' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='320'>
+        <var-decl name='translate' type-id='cf536864' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='384'>
+        <var-decl name='re_nsub' type-id='b59d7dce' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='448'>
+        <var-decl name='can_be_null' type-id='f0981eeb' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='449'>
+        <var-decl name='regs_allocated' type-id='f0981eeb' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='451'>
+        <var-decl name='fastmap_accurate' type-id='f0981eeb' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='452'>
+        <var-decl name='no_sub' type-id='f0981eeb' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='453'>
+        <var-decl name='not_bol' type-id='f0981eeb' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='454'>
+        <var-decl name='not_eol' type-id='f0981eeb' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='455'>
+        <var-decl name='newline_anchor' type-id='f0981eeb' visibility='default'/>
+      </data-member>
+    </class-decl>
+    <typedef-decl name='regex_t' type-id='19fc9a8c' id='aca3bac8'/>
+    <typedef-decl name='uintptr_t' type-id='7359adad' id='e475ab95'/>
     <union-decl name='pthread_mutex_t' size-in-bits='320' naming-typedef-id='7a6844eb' visibility='default' id='70681f9b'>
       <data-member access='public'>
         <var-decl name='__data' type-id='4c734837' visibility='default'/>
@@ -2024,54 +2036,6 @@
     <typedef-decl name='__int32_t' type-id='95e97e5e' id='33f57a65'/>
     <typedef-decl name='__uint32_t' type-id='f0981eeb' id='62f1140c'/>
     <typedef-decl name='__uint64_t' type-id='7359adad' id='8910171f'/>
-    <typedef-decl name='__re_long_size_t' type-id='7359adad' id='ba516949'/>
-    <typedef-decl name='reg_syntax_t' type-id='7359adad' id='1b72c3b3'/>
-    <class-decl name='re_pattern_buffer' size-in-bits='512' is-struct='yes' visibility='default' id='19fc9a8c'>
-      <data-member access='public' layout-offset-in-bits='0'>
-        <var-decl name='buffer' type-id='33976309' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='64'>
-        <var-decl name='allocated' type-id='ba516949' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='128'>
-        <var-decl name='used' type-id='ba516949' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='192'>
-        <var-decl name='syntax' type-id='1b72c3b3' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='256'>
-        <var-decl name='fastmap' type-id='26a90f95' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='320'>
-        <var-decl name='translate' type-id='cf536864' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='384'>
-        <var-decl name='re_nsub' type-id='b59d7dce' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='448'>
-        <var-decl name='can_be_null' type-id='f0981eeb' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='449'>
-        <var-decl name='regs_allocated' type-id='f0981eeb' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='451'>
-        <var-decl name='fastmap_accurate' type-id='f0981eeb' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='452'>
-        <var-decl name='no_sub' type-id='f0981eeb' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='453'>
-        <var-decl name='not_bol' type-id='f0981eeb' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='454'>
-        <var-decl name='not_eol' type-id='f0981eeb' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='455'>
-        <var-decl name='newline_anchor' type-id='f0981eeb' visibility='default'/>
-      </data-member>
-    </class-decl>
-    <typedef-decl name='regex_t' type-id='19fc9a8c' id='aca3bac8'/>
-    <typedef-decl name='uintptr_t' type-id='7359adad' id='e475ab95'/>
     <typedef-decl name='size_t' type-id='7359adad' id='b59d7dce'/>
     <class-decl name='libzfs_handle' size-in-bits='18240' is-struct='yes' visibility='default' id='c8a9d9d8'>
       <data-member access='public' layout-offset-in-bits='0'>
@@ -2236,9 +2200,6 @@
     <class-decl name='uu_avl' is-struct='yes' visibility='default' is-declaration-only='yes' id='4af029d1'/>
     <class-decl name='uu_avl_pool' is-struct='yes' visibility='default' is-declaration-only='yes' id='12a530a8'/>
     <class-decl name='uu_avl_walk' is-struct='yes' visibility='default' is-declaration-only='yes' id='e70a39e3'/>
-    <function-decl name='uu_error' visibility='default' binding='global' size-in-bits='64'>
-      <return type-id='8f92235e'/>
-    </function-decl>
     <function-decl name='uu_avl_pool_create' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='80f4b756'/>
       <parameter type-id='b59d7dce'/>
@@ -2402,14 +2363,6 @@
     <function-decl name='getzoneid' mangled-name='getzoneid' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='getzoneid'>
       <return type-id='4da03624'/>
     </function-decl>
-    <function-decl name='libspl_assertf' mangled-name='libspl_assertf' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='libspl_assertf'>
-      <parameter type-id='80f4b756'/>
-      <parameter type-id='80f4b756'/>
-      <parameter type-id='95e97e5e'/>
-      <parameter type-id='80f4b756'/>
-      <parameter is-variadic='yes'/>
-      <return type-id='48b5725f'/>
-    </function-decl>
     <function-decl name='sa_commit_shares' mangled-name='sa_commit_shares' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='sa_commit_shares'>
       <parameter type-id='9155d4b5'/>
       <return type-id='48b5725f'/>
@@ -2426,13 +2379,6 @@
       <parameter type-id='b59d7dce'/>
       <return type-id='b59d7dce'/>
     </function-decl>
-    <function-decl name='__assert_fail' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='80f4b756'/>
-      <parameter type-id='80f4b756'/>
-      <parameter type-id='f0981eeb'/>
-      <parameter type-id='80f4b756'/>
-      <return type-id='48b5725f'/>
-    </function-decl>
     <function-decl name='free' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='eaa32e2f'/>
       <return type-id='48b5725f'/>
@@ -2500,6 +2446,7 @@
     <array-type-def dimensions='1' type-id='b96825af' size-in-bits='24' id='d3490169'>
       <subrange length='3' type-id='7359adad' id='56f209d2'/>
     </array-type-def>
+    <type-decl name='variadic parameter type' id='2c1145c5'/>
     <typedef-decl name='zpool_iter_f' type-id='3aebb66f' id='fa476e62'/>
     <enum-decl name='data_type_t' naming-typedef-id='8d0687d2' id='aeeae136'>
       <underlying-type type-id='9cac1fee'/>
@@ -2848,6 +2795,14 @@
       <parameter type-id='3fa542f0'/>
       <return type-id='5ce45b60'/>
     </function-decl>
+    <function-decl name='libspl_assertf' mangled-name='libspl_assertf' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='libspl_assertf'>
+      <parameter type-id='80f4b756'/>
+      <parameter type-id='80f4b756'/>
+      <parameter type-id='95e97e5e'/>
+      <parameter type-id='80f4b756'/>
+      <parameter is-variadic='yes'/>
+      <return type-id='48b5725f'/>
+    </function-decl>
     <function-decl name='__errno_location' visibility='default' binding='global' size-in-bits='64'>
       <return type-id='7292109c'/>
     </function-decl>
@@ -2861,11 +2816,6 @@
       <parameter type-id='80f4b756'/>
       <return type-id='26a90f95'/>
     </function-decl>
-    <function-decl name='strcpy' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='26a90f95'/>
-      <parameter type-id='80f4b756'/>
-      <return type-id='26a90f95'/>
-    </function-decl>
     <function-decl name='strchr' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='80f4b756'/>
       <parameter type-id='95e97e5e'/>
@@ -3021,6 +2971,18 @@
       <enumerator name='ZPOOL_NUM_PROPS' value='39'/>
     </enum-decl>
     <typedef-decl name='zpool_prop_t' type-id='af1ba157' id='5d0c23fb'/>
+    <typedef-decl name='regoff_t' type-id='95e97e5e' id='54a2a2a8'/>
+    <class-decl name='regmatch_t' size-in-bits='64' is-struct='yes' naming-typedef-id='1b941664' visibility='default' id='4f932615'>
+      <data-member access='public' layout-offset-in-bits='0'>
+        <var-decl name='rm_so' type-id='54a2a2a8' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='32'>
+        <var-decl name='rm_eo' type-id='54a2a2a8' visibility='default'/>
+      </data-member>
+    </class-decl>
+    <typedef-decl name='regmatch_t' type-id='4f932615' id='1b941664'/>
+    <typedef-decl name='__sighandler_t' type-id='03347643' id='8cdd9566'/>
+    <typedef-decl name='ssize_t' type-id='41060289' id='79a0948f'/>
     <class-decl name='sigaction' size-in-bits='1216' is-struct='yes' visibility='default' id='fe391c48'>
       <data-member access='public' layout-offset-in-bits='0'>
         <var-decl name='__sigaction_handler' type-id='ac5ab595' visibility='default'/>
@@ -3341,18 +3303,6 @@
         <var-decl name='_unused2' type-id='664ac0b7' visibility='default'/>
       </data-member>
     </class-decl>
-    <typedef-decl name='regoff_t' type-id='95e97e5e' id='54a2a2a8'/>
-    <class-decl name='regmatch_t' size-in-bits='64' is-struct='yes' naming-typedef-id='1b941664' visibility='default' id='4f932615'>
-      <data-member access='public' layout-offset-in-bits='0'>
-        <var-decl name='rm_so' type-id='54a2a2a8' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='32'>
-        <var-decl name='rm_eo' type-id='54a2a2a8' visibility='default'/>
-      </data-member>
-    </class-decl>
-    <typedef-decl name='regmatch_t' type-id='4f932615' id='1b941664'/>
-    <typedef-decl name='__sighandler_t' type-id='03347643' id='8cdd9566'/>
-    <typedef-decl name='ssize_t' type-id='41060289' id='79a0948f'/>
     <pointer-type-def type-id='aa12d1ba' size-in-bits='64' id='822cd80b'/>
     <qualified-type-def type-id='822cd80b' restrict='yes' id='e75a27e9'/>
     <pointer-type-def type-id='ec1ed955' size-in-bits='64' id='dca988a5'/>
@@ -3554,42 +3504,18 @@
       <parameter type-id='80f4b756'/>
       <return type-id='822cd80b'/>
     </function-decl>
-    <function-decl name='printf' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='80f4b756'/>
-      <parameter is-variadic='yes'/>
-      <return type-id='95e97e5e'/>
-    </function-decl>
-    <function-decl name='snprintf' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='26a90f95'/>
-      <parameter type-id='b59d7dce'/>
-      <parameter type-id='80f4b756'/>
-      <parameter is-variadic='yes'/>
-      <return type-id='95e97e5e'/>
-    </function-decl>
-    <function-decl name='asprintf' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='8c85230f'/>
-      <parameter type-id='9d26089a'/>
-      <parameter is-variadic='yes'/>
-      <return type-id='95e97e5e'/>
-    </function-decl>
     <function-decl name='fputc' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='95e97e5e'/>
       <parameter type-id='822cd80b'/>
       <return type-id='95e97e5e'/>
     </function-decl>
-    <function-decl name='getline' visibility='default' binding='global' size-in-bits='64'>
+    <function-decl name='__getdelim' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='8c85230f'/>
       <parameter type-id='d19b2c25'/>
+      <parameter type-id='95e97e5e'/>
       <parameter type-id='e75a27e9'/>
       <return type-id='41060289'/>
     </function-decl>
-    <function-decl name='fread' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='1b7446cd'/>
-      <parameter type-id='b59d7dce'/>
-      <parameter type-id='b59d7dce'/>
-      <parameter type-id='e75a27e9'/>
-      <return type-id='b59d7dce'/>
-    </function-decl>
     <function-decl name='rewind' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='822cd80b'/>
       <return type-id='48b5725f'/>
@@ -3611,12 +3537,6 @@
       <parameter type-id='b59d7dce'/>
       <return type-id='eaa32e2f'/>
     </function-decl>
-    <function-decl name='memcpy' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='eaa32e2f'/>
-      <parameter type-id='eaa32e2f'/>
-      <parameter type-id='b59d7dce'/>
-      <return type-id='eaa32e2f'/>
-    </function-decl>
     <function-decl name='strdup' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='80f4b756'/>
       <return type-id='26a90f95'/>
@@ -3641,12 +3561,6 @@
       <parameter type-id='95e97e5e'/>
       <return type-id='95e97e5e'/>
     </function-decl>
-    <function-decl name='read' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='95e97e5e'/>
-      <parameter type-id='eaa32e2f'/>
-      <parameter type-id='b59d7dce'/>
-      <return type-id='79a0948f'/>
-    </function-decl>
     <function-decl name='getpid' visibility='default' binding='global' size-in-bits='64'>
       <return type-id='3629bad8'/>
     </function-decl>
@@ -3658,6 +3572,40 @@
       <parameter type-id='80f4b756'/>
       <return type-id='95e97e5e'/>
     </function-decl>
+    <function-decl name='__open_too_many_args' visibility='default' binding='global' size-in-bits='64'>
+      <return type-id='48b5725f'/>
+    </function-decl>
+    <function-decl name='__open_missing_mode' visibility='default' binding='global' size-in-bits='64'>
+      <return type-id='48b5725f'/>
+    </function-decl>
+    <function-decl name='__printf_chk' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='95e97e5e'/>
+      <parameter type-id='80f4b756'/>
+      <parameter is-variadic='yes'/>
+      <return type-id='95e97e5e'/>
+    </function-decl>
+    <function-decl name='__asprintf_chk' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='8c85230f'/>
+      <parameter type-id='95e97e5e'/>
+      <parameter type-id='9d26089a'/>
+      <parameter is-variadic='yes'/>
+      <return type-id='95e97e5e'/>
+    </function-decl>
+    <function-decl name='__fread_chk' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='1b7446cd'/>
+      <parameter type-id='b59d7dce'/>
+      <parameter type-id='b59d7dce'/>
+      <parameter type-id='b59d7dce'/>
+      <parameter type-id='e75a27e9'/>
+      <return type-id='b59d7dce'/>
+    </function-decl>
+    <function-decl name='__read_chk' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='95e97e5e'/>
+      <parameter type-id='eaa32e2f'/>
+      <parameter type-id='b59d7dce'/>
+      <parameter type-id='b59d7dce'/>
+      <return type-id='79a0948f'/>
+    </function-decl>
     <function-decl name='zfs_crypto_get_encryption_root' mangled-name='zfs_crypto_get_encryption_root' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='zfs_crypto_get_encryption_root'>
       <parameter type-id='9200a744' name='zhp'/>
       <parameter type-id='37e3bd22' name='is_encroot'/>
@@ -3828,55 +3776,6 @@
         <var-decl name='mnt_mntopts' type-id='26a90f95' visibility='default'/>
       </data-member>
     </class-decl>
-    <union-decl name='pthread_mutexattr_t' size-in-bits='32' naming-typedef-id='8afd6070' visibility='default' id='7300eb00'>
-      <data-member access='public'>
-        <var-decl name='__size' type-id='8e0573fd' visibility='default'/>
-      </data-member>
-      <data-member access='public'>
-        <var-decl name='__align' type-id='95e97e5e' visibility='default'/>
-      </data-member>
-    </union-decl>
-    <typedef-decl name='pthread_mutexattr_t' type-id='7300eb00' id='8afd6070'/>
-    <typedef-decl name='int64_t' type-id='0c9942d2' id='9da381c4'/>
-    <typedef-decl name='__int64_t' type-id='bd54fe1a' id='0c9942d2'/>
-    <typedef-decl name='__gid_t' type-id='f0981eeb' id='d94ec6d9'/>
-    <typedef-decl name='__time_t' type-id='bd54fe1a' id='65eda9c0'/>
-    <class-decl name='tm' size-in-bits='448' is-struct='yes' visibility='default' id='dddf6ca2'>
-      <data-member access='public' layout-offset-in-bits='0'>
-        <var-decl name='tm_sec' type-id='95e97e5e' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='32'>
-        <var-decl name='tm_min' type-id='95e97e5e' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='64'>
-        <var-decl name='tm_hour' type-id='95e97e5e' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='96'>
-        <var-decl name='tm_mday' type-id='95e97e5e' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='128'>
-        <var-decl name='tm_mon' type-id='95e97e5e' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='160'>
-        <var-decl name='tm_year' type-id='95e97e5e' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='192'>
-        <var-decl name='tm_wday' type-id='95e97e5e' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='224'>
-        <var-decl name='tm_yday' type-id='95e97e5e' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='256'>
-        <var-decl name='tm_isdst' type-id='95e97e5e' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='320'>
-        <var-decl name='tm_gmtoff' type-id='bd54fe1a' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='384'>
-        <var-decl name='tm_zone' type-id='80f4b756' visibility='default'/>
-      </data-member>
-    </class-decl>
-    <typedef-decl name='time_t' type-id='65eda9c0' id='c9d12d66'/>
     <class-decl name='group' size-in-bits='256' is-struct='yes' visibility='default' id='01a1b934'>
       <data-member access='public' layout-offset-in-bits='0'>
         <var-decl name='gr_name' type-id='26a90f95' visibility='default'/>
@@ -3913,27 +3812,76 @@
     </class-decl>
     <class-decl name='passwd' size-in-bits='384' is-struct='yes' visibility='default' id='a63d15a3'>
       <data-member access='public' layout-offset-in-bits='0'>
-        <var-decl name='pw_name' type-id='26a90f95' visibility='default'/>
+        <var-decl name='pw_name' type-id='26a90f95' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='64'>
+        <var-decl name='pw_passwd' type-id='26a90f95' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='128'>
+        <var-decl name='pw_uid' type-id='cc5fcceb' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='160'>
+        <var-decl name='pw_gid' type-id='d94ec6d9' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='192'>
+        <var-decl name='pw_gecos' type-id='26a90f95' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='256'>
+        <var-decl name='pw_dir' type-id='26a90f95' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='320'>
+        <var-decl name='pw_shell' type-id='26a90f95' visibility='default'/>
+      </data-member>
+    </class-decl>
+    <union-decl name='pthread_mutexattr_t' size-in-bits='32' naming-typedef-id='8afd6070' visibility='default' id='7300eb00'>
+      <data-member access='public'>
+        <var-decl name='__size' type-id='8e0573fd' visibility='default'/>
+      </data-member>
+      <data-member access='public'>
+        <var-decl name='__align' type-id='95e97e5e' visibility='default'/>
+      </data-member>
+    </union-decl>
+    <typedef-decl name='pthread_mutexattr_t' type-id='7300eb00' id='8afd6070'/>
+    <typedef-decl name='int64_t' type-id='0c9942d2' id='9da381c4'/>
+    <typedef-decl name='__int64_t' type-id='bd54fe1a' id='0c9942d2'/>
+    <typedef-decl name='__gid_t' type-id='f0981eeb' id='d94ec6d9'/>
+    <typedef-decl name='__time_t' type-id='bd54fe1a' id='65eda9c0'/>
+    <class-decl name='tm' size-in-bits='448' is-struct='yes' visibility='default' id='dddf6ca2'>
+      <data-member access='public' layout-offset-in-bits='0'>
+        <var-decl name='tm_sec' type-id='95e97e5e' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='32'>
+        <var-decl name='tm_min' type-id='95e97e5e' visibility='default'/>
       </data-member>
       <data-member access='public' layout-offset-in-bits='64'>
-        <var-decl name='pw_passwd' type-id='26a90f95' visibility='default'/>
+        <var-decl name='tm_hour' type-id='95e97e5e' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='96'>
+        <var-decl name='tm_mday' type-id='95e97e5e' visibility='default'/>
       </data-member>
       <data-member access='public' layout-offset-in-bits='128'>
-        <var-decl name='pw_uid' type-id='cc5fcceb' visibility='default'/>
+        <var-decl name='tm_mon' type-id='95e97e5e' visibility='default'/>
       </data-member>
       <data-member access='public' layout-offset-in-bits='160'>
-        <var-decl name='pw_gid' type-id='d94ec6d9' visibility='default'/>
+        <var-decl name='tm_year' type-id='95e97e5e' visibility='default'/>
       </data-member>
       <data-member access='public' layout-offset-in-bits='192'>
-        <var-decl name='pw_gecos' type-id='26a90f95' visibility='default'/>
+        <var-decl name='tm_wday' type-id='95e97e5e' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='224'>
+        <var-decl name='tm_yday' type-id='95e97e5e' visibility='default'/>
       </data-member>
       <data-member access='public' layout-offset-in-bits='256'>
-        <var-decl name='pw_dir' type-id='26a90f95' visibility='default'/>
+        <var-decl name='tm_isdst' type-id='95e97e5e' visibility='default'/>
       </data-member>
       <data-member access='public' layout-offset-in-bits='320'>
-        <var-decl name='pw_shell' type-id='26a90f95' visibility='default'/>
+        <var-decl name='tm_gmtoff' type-id='bd54fe1a' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='384'>
+        <var-decl name='tm_zone' type-id='80f4b756' visibility='default'/>
       </data-member>
     </class-decl>
+    <typedef-decl name='time_t' type-id='65eda9c0' id='c9d12d66'/>
     <typedef-decl name='uid_t' type-id='cc5fcceb' id='354978ed'/>
     <typedef-decl name='prop_changelist_t' type-id='d86edc51' id='eae6431d'/>
     <pointer-type-def type-id='fba6cb51' size-in-bits='64' id='32adbf30'/>
@@ -4434,15 +4382,11 @@
       <parameter type-id='8f2c7109'/>
       <return type-id='95e97e5e'/>
     </function-decl>
-    <function-decl name='fprintf' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='e75a27e9'/>
+    <function-decl name='strtol' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='9d26089a'/>
-      <parameter is-variadic='yes'/>
-      <return type-id='95e97e5e'/>
-    </function-decl>
-    <function-decl name='atoi' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='80f4b756'/>
-      <return type-id='95e97e5e'/>
+      <parameter type-id='8c85230f'/>
+      <parameter type-id='95e97e5e'/>
+      <return type-id='bd54fe1a'/>
     </function-decl>
     <function-decl name='strtoul' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='9d26089a'/>
@@ -4473,12 +4417,6 @@
       <parameter type-id='9d26089a'/>
       <return type-id='26a90f95'/>
     </function-decl>
-    <function-decl name='ioctl' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='95e97e5e'/>
-      <parameter type-id='7359adad'/>
-      <parameter is-variadic='yes'/>
-      <return type-id='95e97e5e'/>
-    </function-decl>
     <function-decl name='strftime' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='266fe297'/>
       <parameter type-id='b59d7dce'/>
@@ -4491,6 +4429,19 @@
       <parameter type-id='f099ad08'/>
       <return type-id='d915a820'/>
     </function-decl>
+    <function-decl name='__fprintf_chk' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='e75a27e9'/>
+      <parameter type-id='95e97e5e'/>
+      <parameter type-id='9d26089a'/>
+      <parameter is-variadic='yes'/>
+      <return type-id='95e97e5e'/>
+    </function-decl>
+    <function-decl name='ioctl' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='95e97e5e'/>
+      <parameter type-id='7359adad'/>
+      <parameter is-variadic='yes'/>
+      <return type-id='95e97e5e'/>
+    </function-decl>
     <function-decl name='zfs_type_to_name' mangled-name='zfs_type_to_name' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='zfs_type_to_name'>
       <parameter type-id='2e45de5d' name='type'/>
       <return type-id='80f4b756'/>
@@ -5156,31 +5107,26 @@
       <parameter type-id='7292109c'/>
       <return type-id='95e97e5e'/>
     </function-decl>
-    <function-decl name='memset' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='eaa32e2f'/>
-      <parameter type-id='95e97e5e'/>
-      <parameter type-id='b59d7dce'/>
-      <return type-id='eaa32e2f'/>
-    </function-decl>
-    <function-decl name='fstat64' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='95e97e5e'/>
-      <parameter type-id='62f7a03d'/>
-      <return type-id='95e97e5e'/>
-    </function-decl>
-    <function-decl name='pread64' visibility='default' binding='global' size-in-bits='64'>
+    <function-decl name='pwrite64' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='95e97e5e'/>
       <parameter type-id='eaa32e2f'/>
       <parameter type-id='b59d7dce'/>
       <parameter type-id='724e4de6'/>
       <return type-id='79a0948f'/>
     </function-decl>
-    <function-decl name='pwrite64' visibility='default' binding='global' size-in-bits='64'>
+    <function-decl name='__pread64_chk' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='95e97e5e'/>
       <parameter type-id='eaa32e2f'/>
       <parameter type-id='b59d7dce'/>
       <parameter type-id='724e4de6'/>
+      <parameter type-id='b59d7dce'/>
       <return type-id='79a0948f'/>
     </function-decl>
+    <function-decl name='fstat64' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='95e97e5e'/>
+      <parameter type-id='62f7a03d'/>
+      <return type-id='95e97e5e'/>
+    </function-decl>
     <function-decl name='zcmd_write_conf_nvlist' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='b0382bb3'/>
       <parameter type-id='e4ec4540'/>
@@ -5381,6 +5327,9 @@
     </class-decl>
     <typedef-decl name='get_all_cb_t' type-id='803dac95' id='9b293607'/>
     <typedef-decl name='tpool_t' type-id='88d1b7f9' id='b1bbf10d'/>
+    <typedef-decl name='DIR' type-id='20cd73f2' id='54a5d683'/>
+    <typedef-decl name='mode_t' type-id='e1c52942' id='d50d396c'/>
+    <typedef-decl name='__compar_fn_t' type-id='585e1de9' id='aba7edd8'/>
     <class-decl name='dirent64' size-in-bits='2240' is-struct='yes' visibility='default' id='5725d813'>
       <data-member access='public' layout-offset-in-bits='0'>
         <var-decl name='d_ino' type-id='71288a47' visibility='default'/>
@@ -5494,9 +5443,6 @@
     <typedef-decl name='__fsblkcnt64_t' type-id='7359adad' id='95fe1a02'/>
     <typedef-decl name='__fsfilcnt64_t' type-id='7359adad' id='0c3a4dde'/>
     <typedef-decl name='__fsword_t' type-id='bd54fe1a' id='6028cbfe'/>
-    <typedef-decl name='DIR' type-id='20cd73f2' id='54a5d683'/>
-    <typedef-decl name='mode_t' type-id='e1c52942' id='d50d396c'/>
-    <typedef-decl name='__compar_fn_t' type-id='585e1de9' id='aba7edd8'/>
     <pointer-type-def type-id='54a5d683' size-in-bits='64' id='f09217ba'/>
     <pointer-type-def type-id='5725d813' size-in-bits='64' id='07b96073'/>
     <pointer-type-def type-id='9b293607' size-in-bits='64' id='77bf1784'/>
@@ -5568,14 +5514,14 @@
       <parameter type-id='9155d4b5'/>
       <return type-id='48b5725f'/>
     </function-decl>
-    <function-decl name='closedir' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='f09217ba'/>
-      <return type-id='95e97e5e'/>
-    </function-decl>
     <function-decl name='fdopendir' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='95e97e5e'/>
       <return type-id='f09217ba'/>
     </function-decl>
+    <function-decl name='closedir' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='f09217ba'/>
+      <return type-id='95e97e5e'/>
+    </function-decl>
     <function-decl name='readdir64' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='f09217ba'/>
       <return type-id='07b96073'/>
@@ -5587,13 +5533,19 @@
       <parameter type-id='aba7edd8'/>
       <return type-id='48b5725f'/>
     </function-decl>
-    <function-decl name='statfs64' visibility='default' binding='global' size-in-bits='64'>
+    <function-decl name='rmdir' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='80f4b756'/>
-      <parameter type-id='7fd094c8'/>
       <return type-id='95e97e5e'/>
     </function-decl>
-    <function-decl name='rmdir' visibility='default' binding='global' size-in-bits='64'>
+    <function-decl name='__openat_too_many_args' visibility='default' binding='global' size-in-bits='64'>
+      <return type-id='48b5725f'/>
+    </function-decl>
+    <function-decl name='__openat_missing_mode' visibility='default' binding='global' size-in-bits='64'>
+      <return type-id='48b5725f'/>
+    </function-decl>
+    <function-decl name='statfs64' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='80f4b756'/>
+      <parameter type-id='7fd094c8'/>
       <return type-id='95e97e5e'/>
     </function-decl>
     <function-decl name='zfs_realloc' visibility='default' binding='global' size-in-bits='64'>
@@ -6077,7 +6029,8 @@
       <enumerator name='SPA_FEATURE_REDACTION_LIST_SPILL' value='39'/>
       <enumerator name='SPA_FEATURE_RAIDZ_EXPANSION' value='40'/>
       <enumerator name='SPA_FEATURE_FAST_DEDUP' value='41'/>
-      <enumerator name='SPA_FEATURES' value='42'/>
+      <enumerator name='SPA_FEATURE_LONGNAME' value='42'/>
+      <enumerator name='SPA_FEATURES' value='43'/>
     </enum-decl>
     <typedef-decl name='spa_feature_t' type-id='33ecb627' id='d6618c78'/>
     <qualified-type-def type-id='80f4b756' const='yes' id='b99c00c9'/>
@@ -6262,10 +6215,6 @@
       <parameter type-id='80f4b756'/>
       <return type-id='c19b74c3'/>
     </function-decl>
-    <function-decl name='zpool_prop_unsupported' mangled-name='zpool_prop_unsupported' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='zpool_prop_unsupported'>
-      <parameter type-id='80f4b756'/>
-      <return type-id='c19b74c3'/>
-    </function-decl>
     <function-decl name='zpool_prop_index_to_string' mangled-name='zpool_prop_index_to_string' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='zpool_prop_index_to_string'>
       <parameter type-id='5d0c23fb'/>
       <parameter type-id='9c313c2d'/>
@@ -6404,11 +6353,6 @@
       <parameter type-id='95e97e5e'/>
       <return type-id='3a47d82b'/>
     </function-decl>
-    <function-decl name='realpath' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='9d26089a'/>
-      <parameter type-id='266fe297'/>
-      <return type-id='26a90f95'/>
-    </function-decl>
     <function-decl name='memcmp' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='eaa32e2f'/>
       <parameter type-id='eaa32e2f'/>
@@ -6421,6 +6365,17 @@
       <parameter type-id='8c85230f'/>
       <return type-id='26a90f95'/>
     </function-decl>
+    <function-decl name='ctime_r' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='d6e2847c'/>
+      <parameter type-id='266fe297'/>
+      <return type-id='26a90f95'/>
+    </function-decl>
+    <function-decl name='__realpath_chk' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='9d26089a'/>
+      <parameter type-id='266fe297'/>
+      <parameter type-id='b59d7dce'/>
+      <return type-id='26a90f95'/>
+    </function-decl>
     <function-decl name='munmap' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='eaa32e2f'/>
       <parameter type-id='b59d7dce'/>
@@ -6431,11 +6386,6 @@
       <parameter type-id='f1cadedf'/>
       <return type-id='95e97e5e'/>
     </function-decl>
-    <function-decl name='ctime_r' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='d6e2847c'/>
-      <parameter type-id='266fe297'/>
-      <return type-id='26a90f95'/>
-    </function-decl>
     <function-decl name='zpool_standard_error' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='b0382bb3'/>
       <parameter type-id='95e97e5e'/>
@@ -7463,6 +7413,23 @@
         <var-decl name='drr_checksum' type-id='39730d0b' visibility='default'/>
       </data-member>
     </class-decl>
+    <class-decl name='__cancel_jmp_buf_tag' size-in-bits='576' is-struct='yes' visibility='default' id='8901473c'>
+      <data-member access='public' layout-offset-in-bits='0'>
+        <var-decl name='__cancel_jmp_buf' type-id='379a1ab7' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='512'>
+        <var-decl name='__mask_was_saved' type-id='95e97e5e' visibility='default'/>
+      </data-member>
+    </class-decl>
+    <class-decl name='__pthread_unwind_buf_t' size-in-bits='832' is-struct='yes' naming-typedef-id='4423cf7f' visibility='default' id='a0abc656'>
+      <data-member access='public' layout-offset-in-bits='0'>
+        <var-decl name='__cancel_jmp_buf' type-id='f5da478b' visibility='default'/>
+      </data-member>
+      <data-member access='public' layout-offset-in-bits='576'>
+        <var-decl name='__pad' type-id='209ef23f' visibility='default'/>
+      </data-member>
+    </class-decl>
+    <typedef-decl name='__pthread_unwind_buf_t' type-id='a0abc656' id='4423cf7f'/>
     <typedef-decl name='__jmp_buf' type-id='5d4efd44' id='379a1ab7'/>
     <typedef-decl name='__clockid_t' type-id='95e97e5e' id='08f9a87a'/>
     <typedef-decl name='__timer_t' type-id='eaa32e2f' id='df209b60'/>
@@ -7509,23 +7476,6 @@
       </data-member>
     </class-decl>
     <typedef-decl name='timer_t' type-id='df209b60' id='b07ae406'/>
-    <class-decl name='__cancel_jmp_buf_tag' size-in-bits='576' is-struct='yes' visibility='default' id='8901473c'>
-      <data-member access='public' layout-offset-in-bits='0'>
-        <var-decl name='__cancel_jmp_buf' type-id='379a1ab7' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='512'>
-        <var-decl name='__mask_was_saved' type-id='95e97e5e' visibility='default'/>
-      </data-member>
-    </class-decl>
-    <class-decl name='__pthread_unwind_buf_t' size-in-bits='832' is-struct='yes' naming-typedef-id='4423cf7f' visibility='default' id='a0abc656'>
-      <data-member access='public' layout-offset-in-bits='0'>
-        <var-decl name='__cancel_jmp_buf' type-id='f5da478b' visibility='default'/>
-      </data-member>
-      <data-member access='public' layout-offset-in-bits='576'>
-        <var-decl name='__pad' type-id='209ef23f' visibility='default'/>
-      </data-member>
-    </class-decl>
-    <typedef-decl name='__pthread_unwind_buf_t' type-id='a0abc656' id='4423cf7f'/>
     <typedef-decl name='Byte' type-id='002ac4a6' id='efb9ba06'/>
     <typedef-decl name='uLong' type-id='7359adad' id='5bbcce85'/>
     <typedef-decl name='Bytef' type-id='efb9ba06' id='c1606520'/>
@@ -7720,12 +7670,6 @@
       <parameter type-id='eaa32e2f'/>
       <return type-id='95e97e5e'/>
     </function-decl>
-    <function-decl name='pthread_sigmask' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='95e97e5e'/>
-      <parameter type-id='5a8729d0'/>
-      <parameter type-id='65e6ec45'/>
-      <return type-id='95e97e5e'/>
-    </function-decl>
     <function-decl name='pthread_exit' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='eaa32e2f'/>
       <return type-id='48b5725f'/>
@@ -7743,12 +7687,6 @@
       <parameter type-id='95e97e5e'/>
       <return type-id='95e97e5e'/>
     </function-decl>
-    <function-decl name='sprintf' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='26a90f95'/>
-      <parameter type-id='80f4b756'/>
-      <parameter is-variadic='yes'/>
-      <return type-id='95e97e5e'/>
-    </function-decl>
     <function-decl name='perror' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='80f4b756'/>
       <return type-id='48b5725f'/>
@@ -7793,6 +7731,12 @@
     <function-decl name='pause' visibility='default' binding='global' size-in-bits='64'>
       <return type-id='95e97e5e'/>
     </function-decl>
+    <function-decl name='pthread_sigmask' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='95e97e5e'/>
+      <parameter type-id='5a8729d0'/>
+      <parameter type-id='65e6ec45'/>
+      <return type-id='95e97e5e'/>
+    </function-decl>
     <function-decl name='uncompress' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='4c667223'/>
       <parameter type-id='60db3356'/>
@@ -8094,6 +8038,10 @@
       <parameter type-id='80f4b756'/>
       <return type-id='26a90f95'/>
     </function-decl>
+    <function-decl name='zpool_prop_unsupported' mangled-name='zpool_prop_unsupported' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='zpool_prop_unsupported'>
+      <parameter type-id='80f4b756'/>
+      <return type-id='c19b74c3'/>
+    </function-decl>
     <function-decl name='zpool_feature_init' mangled-name='zpool_feature_init' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='zpool_feature_init'>
       <return type-id='48b5725f'/>
     </function-decl>
@@ -8161,11 +8109,6 @@
       <parameter type-id='62f7a03d'/>
       <return type-id='95e97e5e'/>
     </function-decl>
-    <function-decl name='pow' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='a0eb0f08'/>
-      <parameter type-id='a0eb0f08'/>
-      <return type-id='a0eb0f08'/>
-    </function-decl>
     <function-decl name='__ctype_toupper_loc' visibility='default' binding='global' size-in-bits='64'>
       <return type-id='24f95ba5'/>
     </function-decl>
@@ -8183,26 +8126,9 @@
       <parameter type-id='d33f11cb'/>
       <return type-id='48b5725f'/>
     </function-decl>
-    <function-decl name='vprintf' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='80f4b756'/>
-      <parameter type-id='b7f2d5e6'/>
-      <return type-id='95e97e5e'/>
-    </function-decl>
-    <function-decl name='vsnprintf' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='26a90f95'/>
-      <parameter type-id='b59d7dce'/>
-      <parameter type-id='80f4b756'/>
-      <parameter type-id='b7f2d5e6'/>
-      <return type-id='95e97e5e'/>
-    </function-decl>
-    <function-decl name='vasprintf' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='8c85230f'/>
-      <parameter type-id='9d26089a'/>
-      <parameter type-id='b7f2d5e6'/>
-      <return type-id='95e97e5e'/>
-    </function-decl>
-    <function-decl name='putchar' visibility='default' binding='global' size-in-bits='64'>
+    <function-decl name='putc' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='95e97e5e'/>
+      <parameter type-id='822cd80b'/>
       <return type-id='95e97e5e'/>
     </function-decl>
     <function-decl name='puts' visibility='default' binding='global' size-in-bits='64'>
@@ -8239,12 +8165,6 @@
       <parameter type-id='b59d7dce'/>
       <return type-id='95e97e5e'/>
     </function-decl>
-    <function-decl name='waitpid' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='3629bad8'/>
-      <parameter type-id='7292109c'/>
-      <parameter type-id='95e97e5e'/>
-      <return type-id='3629bad8'/>
-    </function-decl>
     <function-decl name='access' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='80f4b756'/>
       <parameter type-id='95e97e5e'/>
@@ -8284,6 +8204,31 @@
     <function-decl name='fork' visibility='default' binding='global' size-in-bits='64'>
       <return type-id='3629bad8'/>
     </function-decl>
+    <function-decl name='pow' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='a0eb0f08'/>
+      <parameter type-id='a0eb0f08'/>
+      <return type-id='a0eb0f08'/>
+    </function-decl>
+    <function-decl name='__vfprintf_chk' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='e75a27e9'/>
+      <parameter type-id='95e97e5e'/>
+      <parameter type-id='9d26089a'/>
+      <parameter type-id='b7f2d5e6'/>
+      <return type-id='95e97e5e'/>
+    </function-decl>
+    <function-decl name='__vasprintf_chk' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='8c85230f'/>
+      <parameter type-id='95e97e5e'/>
+      <parameter type-id='9d26089a'/>
+      <parameter type-id='b7f2d5e6'/>
+      <return type-id='95e97e5e'/>
+    </function-decl>
+    <function-decl name='waitpid' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='3629bad8'/>
+      <parameter type-id='7292109c'/>
+      <parameter type-id='95e97e5e'/>
+      <return type-id='3629bad8'/>
+    </function-decl>
     <function-decl name='namespace_clear' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='b0382bb3'/>
       <return type-id='48b5725f'/>
@@ -8454,6 +8399,9 @@
   </abi-instr>
   <abi-instr address-size='64' path='lib/libzfs/os/linux/libzfs_mount_os.c' language='LANG_C99'>
     <pointer-type-def type-id='7359adad' size-in-bits='64' id='1d2c2b85'/>
+    <function-decl name='geteuid' visibility='default' binding='global' size-in-bits='64'>
+      <return type-id='cc5fcceb'/>
+    </function-decl>
     <function-decl name='mount' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='80f4b756'/>
       <parameter type-id='80f4b756'/>
@@ -8467,9 +8415,6 @@
       <parameter type-id='95e97e5e'/>
       <return type-id='95e97e5e'/>
     </function-decl>
-    <function-decl name='geteuid' visibility='default' binding='global' size-in-bits='64'>
-      <return type-id='cc5fcceb'/>
-    </function-decl>
     <function-decl name='zfs_parse_mount_options' mangled-name='zfs_parse_mount_options' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='zfs_parse_mount_options'>
       <parameter type-id='80f4b756' name='mntopts'/>
       <parameter type-id='1d2c2b85' name='mntflags'/>
@@ -8655,11 +8600,12 @@
       </data-member>
     </class-decl>
     <pointer-type-def type-id='b440e872' size-in-bits='64' id='3ac36db0'/>
-    <function-decl name='strtol' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='9d26089a'/>
-      <parameter type-id='8c85230f'/>
+    <function-decl name='__poll_chk' visibility='default' binding='global' size-in-bits='64'>
+      <parameter type-id='3ac36db0'/>
+      <parameter type-id='555eef66'/>
       <parameter type-id='95e97e5e'/>
-      <return type-id='bd54fe1a'/>
+      <parameter type-id='7359adad'/>
+      <return type-id='95e97e5e'/>
     </function-decl>
     <function-decl name='inotify_init1' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='95e97e5e'/>
@@ -8671,12 +8617,6 @@
       <parameter type-id='8f92235e'/>
       <return type-id='95e97e5e'/>
     </function-decl>
-    <function-decl name='poll' visibility='default' binding='global' size-in-bits='64'>
-      <parameter type-id='3ac36db0'/>
-      <parameter type-id='555eef66'/>
-      <parameter type-id='95e97e5e'/>
-      <return type-id='95e97e5e'/>
-    </function-decl>
     <function-decl name='timerfd_create' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='08f9a87a'/>
       <parameter type-id='95e97e5e'/>
@@ -8725,10 +8665,11 @@
       <parameter type-id='80f4b756'/>
       <return type-id='80f4b756'/>
     </function-decl>
-    <function-decl name='readlink' visibility='default' binding='global' size-in-bits='64'>
+    <function-decl name='__readlink_chk' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='9d26089a'/>
       <parameter type-id='266fe297'/>
       <parameter type-id='b59d7dce'/>
+      <parameter type-id='b59d7dce'/>
       <return type-id='79a0948f'/>
     </function-decl>
     <function-decl name='zfs_get_enclosure_sysfs_path' mangled-name='zfs_get_enclosure_sysfs_path' visibility='default' binding='global' size-in-bits='64' elf-symbol-id='zfs_get_enclosure_sysfs_path'>
@@ -8754,10 +8695,10 @@
     <class-decl name='blkid_struct_dev_iterate' is-struct='yes' visibility='default' is-declaration-only='yes' id='d88420d6'/>
     <class-decl name='udev_list_entry' is-struct='yes' visibility='default' is-declaration-only='yes' id='e7dbdca3'/>
     <typedef-decl name='pool_vdev_iter_f' type-id='6c16a6c8' id='dff793e0'/>
-    <typedef-decl name='__useconds_t' type-id='f0981eeb' id='4e80d4b1'/>
     <typedef-decl name='blkid_dev' type-id='8433f053' id='f47b023a'/>
     <typedef-decl name='blkid_cache' type-id='940e3afc' id='0882dfdf'/>
     <typedef-decl name='blkid_dev_iterate' type-id='b8fa2efc' id='f4760fa7'/>
+    <typedef-decl name='__useconds_t' type-id='f0981eeb' id='4e80d4b1'/>
     <pointer-type-def type-id='0882dfdf' size-in-bits='64' id='2e3e7caa'/>
     <pointer-type-def type-id='f47b023a' size-in-bits='64' id='d87f9b75'/>
     <pointer-type-def type-id='09286066' size-in-bits='64' id='940e3afc'/>
@@ -9268,8 +9209,8 @@
     </function-decl>
   </abi-instr>
   <abi-instr address-size='64' path='module/zcommon/zfeature_common.c' language='LANG_C99'>
-    <array-type-def dimensions='1' type-id='83f29ca2' size-in-bits='18816' id='b937914f'>
-      <subrange length='42' type-id='7359adad' id='cb7c937f'/>
+    <array-type-def dimensions='1' type-id='83f29ca2' size-in-bits='19264' id='bd39d632'>
+      <subrange length='43' type-id='7359adad' id='8f7e73a2'/>
     </array-type-def>
     <enum-decl name='zfeature_flags' id='6db816a4'>
       <underlying-type type-id='9cac1fee'/>
@@ -9313,6 +9254,7 @@
       </data-member>
     </class-decl>
     <typedef-decl name='zfeature_info_t' type-id='1178d146' id='83f29ca2'/>
+    <typedef-decl name='__free_fn_t' type-id='b7f9d8e6' id='3ff5e51e'/>
     <class-decl name='dirent' size-in-bits='2240' is-struct='yes' visibility='default' id='611586a1'>
       <data-member access='public' layout-offset-in-bits='0'>
         <var-decl name='d_ino' type-id='71288a47' visibility='default'/>
@@ -9330,7 +9272,6 @@
         <var-decl name='d_name' type-id='d1617432' visibility='default'/>
       </data-member>
     </class-decl>
-    <typedef-decl name='__free_fn_t' type-id='b7f9d8e6' id='3ff5e51e'/>
     <class-decl name='zfs_mod_supported_features' size-in-bits='128' is-struct='yes' visibility='default' id='3eee3342'>
       <data-member access='public' layout-offset-in-bits='0'>
         <var-decl name='tree' type-id='eaa32e2f' visibility='default'/>
@@ -9346,7 +9287,7 @@
     <pointer-type-def type-id='611586a1' size-in-bits='64' id='2e243169'/>
     <qualified-type-def type-id='eaa32e2f' const='yes' id='83be723c'/>
     <pointer-type-def type-id='83be723c' size-in-bits='64' id='7acd98a2'/>
-    <var-decl name='spa_feature_table' type-id='b937914f' mangled-name='spa_feature_table' visibility='default' elf-symbol-id='spa_feature_table'/>
+    <var-decl name='spa_feature_table' type-id='bd39d632' mangled-name='spa_feature_table' visibility='default' elf-symbol-id='spa_feature_table'/>
     <var-decl name='zfeature_checks_disable' type-id='c19b74c3' mangled-name='zfeature_checks_disable' visibility='default' elf-symbol-id='zfeature_checks_disable'/>
     <function-decl name='opendir' visibility='default' binding='global' size-in-bits='64'>
       <parameter type-id='80f4b756'/>
diff --git a/module/os/freebsd/zfs/zfs_znode_os.c b/module/os/freebsd/zfs/zfs_znode_os.c
index fea34273baef..140bb8d80232 100644
--- a/module/os/freebsd/zfs/zfs_znode_os.c
+++ b/module/os/freebsd/zfs/zfs_znode_os.c
@@ -1814,7 +1814,7 @@ zfs_znode_parent_and_name(znode_t *zp, znode_t **dzpp, char *buf)
 		return (SET_ERROR(EINVAL));
 
 	err = zap_value_search(zfsvfs->z_os, parent, zp->z_id,
-	    ZFS_DIRENT_OBJ(-1ULL), buf);
+	    ZFS_DIRENT_OBJ(-1ULL), buf, MAXNAMELEN);
 	if (err != 0)
 		return (err);
 	err = zfs_zget(zfsvfs, parent, dzpp);
diff --git a/module/os/linux/zfs/zfs_dir.c b/module/os/linux/zfs/zfs_dir.c
index ad2ca15e297a..dc03aab2ef96 100644
--- a/module/os/linux/zfs/zfs_dir.c
+++ b/module/os/linux/zfs/zfs_dir.c
@@ -802,6 +802,7 @@ zfs_link_create(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag)
 {
 	znode_t *dzp = dl->dl_dzp;
 	zfsvfs_t *zfsvfs = ZTOZSB(zp);
+	dsl_dataset_t *ds = dmu_objset_ds(zfsvfs->z_os);
 	uint64_t value;
 	int zp_is_dir = S_ISDIR(ZTOI(zp)->i_mode);
 	sa_bulk_attr_t bulk[5];
@@ -847,6 +848,14 @@ zfs_link_create(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag)
 		return (error);
 	}
 
+	/*
+	 * If we added a longname activate the SPA_FEATURE_LONGNAME.
+	 */
+	if (strlen(dl->dl_name) >= ZAP_MAXNAMELEN) {
+		ds->ds_feature_activation[SPA_FEATURE_LONGNAME] =
+		    (void *)B_TRUE;
+	}
+
 	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_PARENT(zfsvfs), NULL,
 	    &dzp->z_id, sizeof (dzp->z_id));
 	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
diff --git a/module/os/linux/zfs/zfs_vfsops.c b/module/os/linux/zfs/zfs_vfsops.c
index a6d1202e424f..a24f504129d7 100644
--- a/module/os/linux/zfs/zfs_vfsops.c
+++ b/module/os/linux/zfs/zfs_vfsops.c
@@ -57,6 +57,7 @@
 #include <sys/dmu_objset.h>
 #include <sys/dsl_dir.h>
 #include <sys/objlist.h>
+#include <sys/zfeature.h>
 #include <sys/zpl.h>
 #include <linux/vfs_compat.h>
 #include <linux/fs.h>
@@ -449,6 +450,12 @@ acl_inherit_changed_cb(void *arg, uint64_t newval)
 	((zfsvfs_t *)arg)->z_acl_inherit = newval;
 }
 
+static void
+longname_changed_cb(void *arg, uint64_t newval)
+{
+	((zfsvfs_t *)arg)->z_longname = newval;
+}
+
 static int
 zfs_register_callbacks(vfs_t *vfsp)
 {
@@ -509,6 +516,8 @@ zfs_register_callbacks(vfs_t *vfsp)
 	    zfsvfs);
 	error = error ? error : dsl_prop_register(ds,
 	    zfs_prop_to_name(ZFS_PROP_NBMAND), nbmand_changed_cb, zfsvfs);
+	error = error ? error : dsl_prop_register(ds,
+	    zfs_prop_to_name(ZFS_PROP_LONGNAME), longname_changed_cb, zfsvfs);
 	dsl_pool_config_exit(dmu_objset_pool(os), FTAG);
 	if (error)
 		goto unregister;
@@ -1140,7 +1149,8 @@ zfs_statvfs(struct inode *ip, struct kstatfs *statp)
 	statp->f_fsid.val[0] = (uint32_t)fsid;
 	statp->f_fsid.val[1] = (uint32_t)(fsid >> 32);
 	statp->f_type = ZFS_SUPER_MAGIC;
-	statp->f_namelen = MAXNAMELEN - 1;
+	statp->f_namelen =
+	    zfsvfs->z_longname ? (ZAP_MAXNAMELEN_NEW - 1) : (MAXNAMELEN - 1);
 
 	/*
 	 * We have all of 40 characters to stuff a string here.
diff --git a/module/os/linux/zfs/zfs_vnops_os.c b/module/os/linux/zfs/zfs_vnops_os.c
index 4f1cf3fdcb7e..dd9fd760b9c2 100644
--- a/module/os/linux/zfs/zfs_vnops_os.c
+++ b/module/os/linux/zfs/zfs_vnops_os.c
@@ -533,6 +533,46 @@ zfs_lookup(znode_t *zdp, char *nm, znode_t **zpp, int flags, cred_t *cr,
 	return (error);
 }
 
+/*
+ * Perform a linear search in directory for the name of specific inode.
+ * Note we don't pass in the buffer size of name because it's hardcoded to
+ * NAME_MAX+1(256) in Linux.
+ *
+ *	IN:	dzp	- znode of directory to search.
+ *		zp	- znode of the target
+ *
+ *	OUT:	name	- dentry name of the target
+ *
+ *	RETURN:	0 on success, error code on failure.
+ */
+int
+zfs_get_name(znode_t *dzp, char *name, znode_t *zp)
+{
+	zfsvfs_t *zfsvfs = ZTOZSB(dzp);
+	int error = 0;
+
+	if ((error = zfs_enter_verify_zp(zfsvfs, dzp, FTAG)) != 0)
+		return (error);
+
+	if ((error = zfs_verify_zp(zp)) != 0) {
+		zfs_exit(zfsvfs, FTAG);
+		return (error);
+	}
+
+	/* ctldir should have got their name in zfs_vget */
+	if (dzp->z_is_ctldir || zp->z_is_ctldir) {
+		zfs_exit(zfsvfs, FTAG);
+		return (ENOENT);
+	}
+
+	/* buffer len is hardcoded to 256 in Linux kernel */
+	error = zap_value_search(zfsvfs->z_os, dzp->z_id, zp->z_id,
+	    ZFS_DIRENT_OBJ(-1ULL), name, ZAP_MAXNAMELEN);
+
+	zfs_exit(zfsvfs, FTAG);
+	return (error);
+}
+
 /*
  * Attempt to create a new entry in a directory.  If the entry
  * already exists, truncate the file if permissible, else return
@@ -1539,7 +1579,7 @@ zfs_readdir(struct inode *ip, struct dir_context *ctx, cred_t *cr)
 	os = zfsvfs->z_os;
 	offset = ctx->pos;
 	prefetch = zp->z_zn_prefetch;
-	zap = zap_attribute_alloc();
+	zap = zap_attribute_long_alloc();
 
 	/*
 	 * Initialize the iterator cursor.
diff --git a/module/os/linux/zfs/zpl_export.c b/module/os/linux/zfs/zpl_export.c
index b6b9e2754055..ff865d129954 100644
--- a/module/os/linux/zfs/zpl_export.c
+++ b/module/os/linux/zfs/zpl_export.c
@@ -24,6 +24,7 @@
  */
 
 
+#include <sys/file.h>
 #include <sys/zfs_znode.h>
 #include <sys/zfs_vnops.h>
 #include <sys/zfs_ctldir.h>
@@ -102,6 +103,35 @@ zpl_fh_to_dentry(struct super_block *sb, struct fid *fh,
 	return (d_obtain_alias(ip));
 }
 
+/*
+ * In case the filesystem contains name longer than 255, we need to override
+ * the default get_name so we don't get buffer overflow. Unfortunately, since
+ * the buffer size is hardcoded in Linux, we will get ESTALE error in this
+ * case.
+ */
+static int
+zpl_get_name(struct dentry *parent, char *name, struct dentry *child)
+{
+	cred_t *cr = CRED();
+	fstrans_cookie_t cookie;
+	struct inode *dir = parent->d_inode;
+	struct inode *ip = child->d_inode;
+	int error;
+
+	if (!dir || !S_ISDIR(dir->i_mode))
+		return (-ENOTDIR);
+
+	crhold(cr);
+	cookie = spl_fstrans_mark();
+	spl_inode_lock_shared(dir);
+	error = -zfs_get_name(ITOZ(dir), name, ITOZ(ip));
+	spl_inode_unlock_shared(dir);
+	spl_fstrans_unmark(cookie);
+	crfree(cr);
+
+	return (error);
+}
+
 static struct dentry *
 zpl_get_parent(struct dentry *child)
 {
@@ -146,6 +176,7 @@ zpl_commit_metadata(struct inode *inode)
 const struct export_operations zpl_export_operations = {
 	.encode_fh		= zpl_encode_fh,
 	.fh_to_dentry		= zpl_fh_to_dentry,
+	.get_name		= zpl_get_name,
 	.get_parent		= zpl_get_parent,
 	.commit_metadata	= zpl_commit_metadata,
 };
diff --git a/module/os/linux/zfs/zpl_inode.c b/module/os/linux/zfs/zpl_inode.c
index 8386fc2ae0ce..c4b5087ca5e7 100644
--- a/module/os/linux/zfs/zpl_inode.c
+++ b/module/os/linux/zfs/zpl_inode.c
@@ -46,9 +46,29 @@ zpl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
 	pathname_t pn;
 	int zfs_flags = 0;
 	zfsvfs_t *zfsvfs = dentry->d_sb->s_fs_info;
+	dsl_dataset_t *ds = dmu_objset_ds(zfsvfs->z_os);
+	size_t dlen = dlen(dentry);
 
-	if (dlen(dentry) >= ZAP_MAXNAMELEN)
+	/*
+	 * If z_longname is disabled, disallow create or rename of names
+	 * longer than ZAP_MAXNAMELEN.
+	 *
+	 * This is needed in cases where longname was enabled first and some
+	 * files/dirs with names > ZAP_MAXNAMELEN were created. And later
+	 * longname was disabled. In such a case allow access to existing
+	 * longnames. But disallow creation newer longnamed entities.
+	 */
+	if (!zfsvfs->z_longname && (dlen >= ZAP_MAXNAMELEN)) {
+		/*
+		 * If this is for create or rename fail it.
+		 */
+		if (!dsl_dataset_feature_is_active(ds, SPA_FEATURE_LONGNAME) ||
+		    (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET)))
+			return (ERR_PTR(-ENAMETOOLONG));
+	}
+	if (dlen >= ZAP_MAXNAMELEN_NEW) {
 		return (ERR_PTR(-ENAMETOOLONG));
+	}
 
 	crhold(cr);
 	cookie = spl_fstrans_mark();
@@ -131,6 +151,16 @@ zpl_vap_init(vattr_t *vap, struct inode *dir, umode_t mode, cred_t *cr,
 	}
 }
 
+static inline bool
+is_nametoolong(struct dentry *dentry)
+{
+	zfsvfs_t *zfsvfs = dentry->d_sb->s_fs_info;
+	size_t dlen = dlen(dentry);
+
+	return ((!zfsvfs->z_longname && dlen >= ZAP_MAXNAMELEN) ||
+	    dlen >= ZAP_MAXNAMELEN_NEW);
+}
+
 static int
 #ifdef HAVE_IOPS_CREATE_USERNS
 zpl_create(struct user_namespace *user_ns, struct inode *dir,
@@ -151,6 +181,10 @@ zpl_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool flag)
 	zidmap_t *user_ns = kcred->user_ns;
 #endif
 
+	if (is_nametoolong(dentry)) {
+		return (-ENAMETOOLONG);
+	}
+
 	crhold(cr);
 	vap = kmem_zalloc(sizeof (vattr_t), KM_SLEEP);
 	zpl_vap_init(vap, dir, mode, cr, user_ns);
@@ -201,6 +235,10 @@ zpl_mknod(struct inode *dir, struct dentry *dentry, umode_t mode,
 	zidmap_t *user_ns = kcred->user_ns;
 #endif
 
+	if (is_nametoolong(dentry)) {
+		return (-ENAMETOOLONG);
+	}
+
 	/*
 	 * We currently expect Linux to supply rdev=0 for all sockets
 	 * and fifos, but we want to know if this behavior ever changes.
@@ -353,6 +391,10 @@ zpl_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 	zidmap_t *user_ns = kcred->user_ns;
 #endif
 
+	if (is_nametoolong(dentry)) {
+		return (-ENAMETOOLONG);
+	}
+
 	crhold(cr);
 	vap = kmem_zalloc(sizeof (vattr_t), KM_SLEEP);
 	zpl_vap_init(vap, dir, mode | S_IFDIR, cr, user_ns);
@@ -568,6 +610,10 @@ zpl_rename2(struct inode *sdip, struct dentry *sdentry,
 	zidmap_t *user_ns = kcred->user_ns;
 #endif
 
+	if (is_nametoolong(tdentry)) {
+		return (-ENAMETOOLONG);
+	}
+
 	crhold(cr);
 	if (rflags & RENAME_WHITEOUT) {
 		wo_vap = kmem_zalloc(sizeof (vattr_t), KM_SLEEP);
@@ -618,6 +664,10 @@ zpl_symlink(struct inode *dir, struct dentry *dentry, const char *name)
 	zidmap_t *user_ns = kcred->user_ns;
 #endif
 
+	if (is_nametoolong(dentry)) {
+		return (-ENAMETOOLONG);
+	}
+
 	crhold(cr);
 	vap = kmem_zalloc(sizeof (vattr_t), KM_SLEEP);
 	zpl_vap_init(vap, dir, S_IFLNK | S_IRWXUGO, cr, user_ns);
@@ -707,6 +757,10 @@ zpl_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
 	int error;
 	fstrans_cookie_t cookie;
 
+	if (is_nametoolong(dentry)) {
+		return (-ENAMETOOLONG);
+	}
+
 	if (ip->i_nlink >= ZFS_LINK_MAX)
 		return (-EMLINK);
 
diff --git a/module/zcommon/zfeature_common.c b/module/zcommon/zfeature_common.c
index 8dec5f27b0af..881deb5bf666 100644
--- a/module/zcommon/zfeature_common.c
+++ b/module/zcommon/zfeature_common.c
@@ -760,6 +760,18 @@ zpool_feature_init(void)
 	    ZFEATURE_FLAG_READONLY_COMPAT, ZFEATURE_TYPE_BOOLEAN, NULL,
 	    sfeatures);
 
+	{
+		static const spa_feature_t longname_deps[] = {
+			SPA_FEATURE_EXTENSIBLE_DATASET,
+			SPA_FEATURE_NONE
+		};
+		zfeature_register(SPA_FEATURE_LONGNAME,
+		    "org.zfsonlinux:longname", "longname",
+		    "support filename up to 1024 bytes",
+		    ZFEATURE_FLAG_PER_DATASET, ZFEATURE_TYPE_BOOLEAN,
+		    longname_deps, sfeatures);
+	}
+
 	zfs_mod_list_supported_free(sfeatures);
 }
 
diff --git a/module/zcommon/zfs_prop.c b/module/zcommon/zfs_prop.c
index 20cc0dffc27e..8179a1a8c39d 100644
--- a/module/zcommon/zfs_prop.c
+++ b/module/zcommon/zfs_prop.c
@@ -772,6 +772,10 @@ zfs_prop_init(void)
 	    ZFS_TYPE_VOLUME, "<date>", "SNAPSHOTS_CHANGED", B_FALSE, B_TRUE,
 	    B_TRUE, NULL, sfeatures);
 
+	zprop_register_index(ZFS_PROP_LONGNAME, "longname", 0, PROP_INHERIT,
+	    ZFS_TYPE_FILESYSTEM, "on | off", "LONGNAME", boolean_table,
+	    sfeatures);
+
 	zfs_mod_list_supported_free(sfeatures);
 }
 
diff --git a/module/zfs/dmu_recv.c b/module/zfs/dmu_recv.c
index 9b3da032f354..4877eb7e62f8 100644
--- a/module/zfs/dmu_recv.c
+++ b/module/zfs/dmu_recv.c
@@ -602,6 +602,13 @@ recv_begin_check_feature_flags_impl(uint64_t featureflags, spa_t *spa)
 	    !spa_feature_is_enabled(spa, SPA_FEATURE_REDACTED_DATASETS))
 		return (SET_ERROR(ENOTSUP));
 
+	/*
+	 * If the LONGNAME is not enabled on the target, fail that request.
+	 */
+	if ((featureflags & DMU_BACKUP_FEATURE_LONGNAME) &&
+	    !spa_feature_is_enabled(spa, SPA_FEATURE_LONGNAME))
+		return (SET_ERROR(ENOTSUP));
+
 	return (0);
 }
 
@@ -990,6 +997,16 @@ dmu_recv_begin_sync(void *arg, dmu_tx_t *tx)
 	dmu_buf_will_dirty(newds->ds_dbuf, tx);
 	dsl_dataset_phys(newds)->ds_flags |= DS_FLAG_INCONSISTENT;
 
+	/*
+	 * Activate longname feature if received
+	 */
+	if (featureflags & DMU_BACKUP_FEATURE_LONGNAME &&
+	    !dsl_dataset_feature_is_active(newds, SPA_FEATURE_LONGNAME)) {
+		dsl_dataset_activate_feature(newds->ds_object,
+		    SPA_FEATURE_LONGNAME, (void *)B_TRUE, tx);
+		newds->ds_feature[SPA_FEATURE_LONGNAME] = (void *)B_TRUE;
+	}
+
 	/*
 	 * If we actually created a non-clone, we need to create the objset
 	 * in our new dataset. If this is a raw send we postpone this until
diff --git a/module/zfs/dmu_send.c b/module/zfs/dmu_send.c
index cb2b62fed313..c7d3a5cb6e7f 100644
--- a/module/zfs/dmu_send.c
+++ b/module/zfs/dmu_send.c
@@ -2011,6 +2011,10 @@ setup_featureflags(struct dmu_send_params *dspp, objset_t *os,
 	if (dsl_dataset_feature_is_active(to_ds, SPA_FEATURE_LARGE_DNODE)) {
 		*featureflags |= DMU_BACKUP_FEATURE_LARGE_DNODE;
 	}
+
+	if (dsl_dataset_feature_is_active(to_ds, SPA_FEATURE_LONGNAME)) {
+		*featureflags |= DMU_BACKUP_FEATURE_LONGNAME;
+	}
 	return (0);
 }
 
diff --git a/module/zfs/dsl_dataset.c b/module/zfs/dsl_dataset.c
index aa02af55722d..6a9ed891093b 100644
--- a/module/zfs/dsl_dataset.c
+++ b/module/zfs/dsl_dataset.c
@@ -494,7 +494,8 @@ dsl_dataset_get_snapname(dsl_dataset_t *ds)
 		return (err);
 	headphys = headdbuf->db_data;
 	err = zap_value_search(dp->dp_meta_objset,
-	    headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname);
+	    headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname,
+	    sizeof (ds->ds_snapname));
 	if (err != 0 && zfs_recover == B_TRUE) {
 		err = 0;
 		(void) snprintf(ds->ds_snapname, sizeof (ds->ds_snapname),
diff --git a/module/zfs/dsl_dir.c b/module/zfs/dsl_dir.c
index 5aeff86b948f..1b60fa620b8d 100644
--- a/module/zfs/dsl_dir.c
+++ b/module/zfs/dsl_dir.c
@@ -239,7 +239,8 @@ dsl_dir_hold_obj(dsl_pool_t *dp, uint64_t ddobj,
 				err = zap_value_search(dp->dp_meta_objset,
 				    dsl_dir_phys(dd->dd_parent)->
 				    dd_child_dir_zapobj,
-				    ddobj, 0, dd->dd_myname);
+				    ddobj, 0, dd->dd_myname,
+				    sizeof (dd->dd_myname));
 			}
 			if (err != 0)
 				goto errout;
diff --git a/module/zfs/zap.c b/module/zfs/zap.c
index 603c76a2cd9b..e3d0faca1759 100644
--- a/module/zfs/zap.c
+++ b/module/zfs/zap.c
@@ -832,7 +832,12 @@ zap_put_leaf_maybe_grow_ptrtbl(zap_name_t *zn, zap_leaf_t *l,
 static int
 fzap_checkname(zap_name_t *zn)
 {
-	if (zn->zn_key_orig_numints * zn->zn_key_intlen > ZAP_MAXNAMELEN)
+	uint32_t maxnamelen = zn->zn_normbuf_len;
+	uint64_t len = (uint64_t)zn->zn_key_orig_numints * zn->zn_key_intlen;
+	/* Only allow directory zap to have longname */
+	if (len > maxnamelen ||
+	    (zn->zn_zap->zap_dnode->dn_type != DMU_OT_DIRECTORY_CONTENTS &&
+	    len > ZAP_MAXNAMELEN))
 		return (SET_ERROR(ENAMETOOLONG));
 	return (0);
 }
@@ -1102,7 +1107,7 @@ zap_create_link_dnsize(objset_t *os, dmu_object_type_t ot, uint64_t parent_obj,
 
 int
 zap_value_search(objset_t *os, uint64_t zapobj, uint64_t value, uint64_t mask,
-    char *name)
+    char *name, uint64_t namelen)
 {
 	zap_cursor_t zc;
 	int err;
@@ -1110,12 +1115,13 @@ zap_value_search(objset_t *os, uint64_t zapobj, uint64_t value, uint64_t mask,
 	if (mask == 0)
 		mask = -1ULL;
 
-	zap_attribute_t *za = zap_attribute_alloc();
+	zap_attribute_t *za = zap_attribute_long_alloc();
 	for (zap_cursor_init(&zc, os, zapobj);
 	    (err = zap_cursor_retrieve(&zc, za)) == 0;
 	    zap_cursor_advance(&zc)) {
 		if ((za->za_first_integer & mask) == (value & mask)) {
-			(void) strlcpy(name, za->za_name, MAXNAMELEN);
+			if (strlcpy(name, za->za_name, namelen) >= namelen)
+				err = SET_ERROR(ENAMETOOLONG);
 			break;
 		}
 	}
@@ -1130,7 +1136,7 @@ zap_join(objset_t *os, uint64_t fromobj, uint64_t intoobj, dmu_tx_t *tx)
 	zap_cursor_t zc;
 	int err = 0;
 
-	zap_attribute_t *za = zap_attribute_alloc();
+	zap_attribute_t *za = zap_attribute_long_alloc();
 	for (zap_cursor_init(&zc, os, fromobj);
 	    zap_cursor_retrieve(&zc, za) == 0;
 	    (void) zap_cursor_advance(&zc)) {
@@ -1155,7 +1161,7 @@ zap_join_key(objset_t *os, uint64_t fromobj, uint64_t intoobj,
 	zap_cursor_t zc;
 	int err = 0;
 
-	zap_attribute_t *za = zap_attribute_alloc();
+	zap_attribute_t *za = zap_attribute_long_alloc();
 	for (zap_cursor_init(&zc, os, fromobj);
 	    zap_cursor_retrieve(&zc, za) == 0;
 	    (void) zap_cursor_advance(&zc)) {
@@ -1180,7 +1186,7 @@ zap_join_increment(objset_t *os, uint64_t fromobj, uint64_t intoobj,
 	zap_cursor_t zc;
 	int err = 0;
 
-	zap_attribute_t *za = zap_attribute_alloc();
+	zap_attribute_t *za = zap_attribute_long_alloc();
 	for (zap_cursor_init(&zc, os, fromobj);
 	    zap_cursor_retrieve(&zc, za) == 0;
 	    (void) zap_cursor_advance(&zc)) {
diff --git a/module/zfs/zap_micro.c b/module/zfs/zap_micro.c
index e52680dd40c0..699e36a3236c 100644
--- a/module/zfs/zap_micro.c
+++ b/module/zfs/zap_micro.c
@@ -131,12 +131,12 @@ zap_hash(zap_name_t *zn)
 }
 
 static int
-zap_normalize(zap_t *zap, const char *name, char *namenorm, int normflags)
+zap_normalize(zap_t *zap, const char *name, char *namenorm, int normflags,
+    size_t outlen)
 {
 	ASSERT(!(zap_getflags(zap) & ZAP_FLAG_UINT64_KEY));
 
 	size_t inlen = strlen(name) + 1;
-	size_t outlen = ZAP_MAXNAMELEN;
 
 	int err = 0;
 	(void) u8_textprep_str((char *)name, &inlen, namenorm, &outlen,
@@ -149,23 +149,31 @@ zap_normalize(zap_t *zap, const char *name, char *namenorm, int normflags)
 boolean_t
 zap_match(zap_name_t *zn, const char *matchname)
 {
+	boolean_t res = B_FALSE;
 	ASSERT(!(zap_getflags(zn->zn_zap) & ZAP_FLAG_UINT64_KEY));
 
 	if (zn->zn_matchtype & MT_NORMALIZE) {
-		char norm[ZAP_MAXNAMELEN];
+		size_t namelen = zn->zn_normbuf_len;
+		char *norm;
 
+		norm = kmem_alloc(namelen, KM_SLEEP);
 		if (zap_normalize(zn->zn_zap, matchname, norm,
-		    zn->zn_normflags) != 0)
-			return (B_FALSE);
-
-		return (strcmp(zn->zn_key_norm, norm) == 0);
+		    zn->zn_normflags, namelen) != 0) {
+			res = B_FALSE;
+		} else {
+			res = (strcmp(zn->zn_key_norm, norm) == 0);
+		}
+		kmem_free(norm, namelen);
 	} else {
-		return (strcmp(zn->zn_key_orig, matchname) == 0);
+		res = (strcmp(zn->zn_key_orig, matchname) == 0);
 	}
+	return (res);
 }
 
 static kmem_cache_t *zap_name_cache;
 static kmem_cache_t *zap_attr_cache;
+static kmem_cache_t *zap_name_long_cache;
+static kmem_cache_t *zap_attr_long_cache;
 
 void
 zap_init(void)
@@ -177,6 +185,14 @@ zap_init(void)
 	zap_attr_cache = kmem_cache_create("zap_attr_cache",
 	    sizeof (zap_attribute_t) + ZAP_MAXNAMELEN,  0, NULL,
 	    NULL, NULL, NULL, NULL, 0);
+
+	zap_name_long_cache = kmem_cache_create("zap_name_long",
+	    sizeof (zap_name_t) + ZAP_MAXNAMELEN_NEW, 0, NULL, NULL,
+	    NULL, NULL, NULL, 0);
+
+	zap_attr_long_cache = kmem_cache_create("zap_attr_long_cache",
+	    sizeof (zap_attribute_t) + ZAP_MAXNAMELEN_NEW,  0, NULL,
+	    NULL, NULL, NULL, NULL, 0);
 }
 
 void
@@ -184,33 +200,47 @@ zap_fini(void)
 {
 	kmem_cache_destroy(zap_name_cache);
 	kmem_cache_destroy(zap_attr_cache);
+	kmem_cache_destroy(zap_name_long_cache);
+	kmem_cache_destroy(zap_attr_long_cache);
 }
 
 static zap_name_t *
-zap_name_alloc(zap_t *zap)
+zap_name_alloc(zap_t *zap, boolean_t longname)
 {
-	zap_name_t *zn = kmem_cache_alloc(zap_name_cache, KM_SLEEP);
+	kmem_cache_t *cache = longname ? zap_name_long_cache : zap_name_cache;
+	zap_name_t *zn = kmem_cache_alloc(cache, KM_SLEEP);
+
 	zn->zn_zap = zap;
+	zn->zn_normbuf_len = longname ? ZAP_MAXNAMELEN_NEW : ZAP_MAXNAMELEN;
 	return (zn);
 }
 
 void
 zap_name_free(zap_name_t *zn)
 {
-	kmem_cache_free(zap_name_cache, zn);
+	if (zn->zn_normbuf_len == ZAP_MAXNAMELEN) {
+		kmem_cache_free(zap_name_cache, zn);
+	} else {
+		ASSERT3U(zn->zn_normbuf_len, ==, ZAP_MAXNAMELEN_NEW);
+		kmem_cache_free(zap_name_long_cache, zn);
+	}
 }
 
 static int
 zap_name_init_str(zap_name_t *zn, const char *key, matchtype_t mt)
 {
 	zap_t *zap = zn->zn_zap;
+	size_t key_len = strlen(key) + 1;
+
+	/* Make sure zn is allocated for longname if key is long */
+	IMPLY(key_len > ZAP_MAXNAMELEN,
+	    zn->zn_normbuf_len == ZAP_MAXNAMELEN_NEW);
 
 	zn->zn_key_intlen = sizeof (*key);
 	zn->zn_key_orig = key;
-	zn->zn_key_orig_numints = strlen(zn->zn_key_orig) + 1;
+	zn->zn_key_orig_numints = key_len;
 	zn->zn_matchtype = mt;
 	zn->zn_normflags = zap->zap_normflags;
-	zn->zn_normbuf_len = ZAP_MAXNAMELEN;
 
 	/*
 	 * If we're dealing with a case sensitive lookup on a mixed or
@@ -226,7 +256,7 @@ zap_name_init_str(zap_name_t *zn, const char *key, matchtype_t mt)
 		 * what the hash is computed from.
 		 */
 		if (zap_normalize(zap, key, zn->zn_normbuf,
-		    zap->zap_normflags) != 0)
+		    zap->zap_normflags, zn->zn_normbuf_len) != 0)
 			return (SET_ERROR(ENOTSUP));
 		zn->zn_key_norm = zn->zn_normbuf;
 		zn->zn_key_norm_numints = strlen(zn->zn_key_norm) + 1;
@@ -245,7 +275,7 @@ zap_name_init_str(zap_name_t *zn, const char *key, matchtype_t mt)
 		 * what the matching is based on.  (Not the hash!)
 		 */
 		if (zap_normalize(zap, key, zn->zn_normbuf,
-		    zn->zn_normflags) != 0)
+		    zn->zn_normflags, zn->zn_normbuf_len) != 0)
 			return (SET_ERROR(ENOTSUP));
 		zn->zn_key_norm_numints = strlen(zn->zn_key_norm) + 1;
 	}
@@ -256,7 +286,8 @@ zap_name_init_str(zap_name_t *zn, const char *key, matchtype_t mt)
 zap_name_t *
 zap_name_alloc_str(zap_t *zap, const char *key, matchtype_t mt)
 {
-	zap_name_t *zn = zap_name_alloc(zap);
+	size_t key_len = strlen(key) + 1;
+	zap_name_t *zn = zap_name_alloc(zap, (key_len > ZAP_MAXNAMELEN));
 	if (zap_name_init_str(zn, key, mt) != 0) {
 		zap_name_free(zn);
 		return (NULL);
@@ -491,7 +522,7 @@ mzap_open(dmu_buf_t *db)
 		zfs_btree_create_custom(&zap->zap_m.zap_tree, mze_compare,
 		    mze_find_in_buf, sizeof (mzap_ent_t), 512);
 
-		zap_name_t *zn = zap_name_alloc(zap);
+		zap_name_t *zn = zap_name_alloc(zap, B_FALSE);
 		for (uint16_t i = 0; i < zap->zap_m.zap_num_chunks; i++) {
 			mzap_ent_phys_t *mze =
 			    &zap_m_phys(zap)->mz_chunk[i];
@@ -698,7 +729,7 @@ mzap_upgrade(zap_t **zapp, const void *tag, dmu_tx_t *tx, zap_flags_t flags)
 
 	fzap_upgrade(zap, tx, flags);
 
-	zap_name_t *zn = zap_name_alloc(zap);
+	zap_name_t *zn = zap_name_alloc(zap, B_FALSE);
 	for (int i = 0; i < nchunks; i++) {
 		mzap_ent_phys_t *mze = &mzp->mz_chunk[i];
 		if (mze->mze_name[0] == 0)
@@ -1625,21 +1656,38 @@ zap_remove_uint64_by_dnode(dnode_t *dn, const uint64_t *key, int key_numints,
 }
 
 
-zap_attribute_t *
-zap_attribute_alloc(void)
+static zap_attribute_t *
+zap_attribute_alloc_impl(boolean_t longname)
 {
-	uint32_t len = ZAP_MAXNAMELEN;
 	zap_attribute_t *za;
 
-	za = kmem_cache_alloc(zap_attr_cache, KM_SLEEP);
-	za->za_name_len = len;
+	za = kmem_cache_alloc((longname)? zap_attr_long_cache : zap_attr_cache,
+	    KM_SLEEP);
+	za->za_name_len = (longname)? ZAP_MAXNAMELEN_NEW : ZAP_MAXNAMELEN;
 	return (za);
 }
 
+zap_attribute_t *
+zap_attribute_alloc(void)
+{
+	return (zap_attribute_alloc_impl(B_FALSE));
+}
+
+zap_attribute_t *
+zap_attribute_long_alloc(void)
+{
+	return (zap_attribute_alloc_impl(B_TRUE));
+}
+
 void
 zap_attribute_free(zap_attribute_t *za)
 {
-	kmem_cache_free(zap_attr_cache, za);
+	if (za->za_name_len == ZAP_MAXNAMELEN) {
+		kmem_cache_free(zap_attr_cache, za);
+	} else {
+		ASSERT3U(za->za_name_len, ==, ZAP_MAXNAMELEN_NEW);
+		kmem_cache_free(zap_attr_long_cache, za);
+	}
 }
 
 /*
diff --git a/module/zfs/zfs_ioctl.c b/module/zfs/zfs_ioctl.c
index e69b98896a28..8188a9e46865 100644
--- a/module/zfs/zfs_ioctl.c
+++ b/module/zfs/zfs_ioctl.c
@@ -2594,6 +2594,41 @@ zfs_prop_set_special(const char *dsname, zprop_source_t source,
 		}
 		break;
 	}
+	case ZFS_PROP_LONGNAME:
+	{
+		zfsvfs_t *zfsvfs;
+
+		/*
+		 * Ignore the checks if the property is being applied as part of
+		 * 'zfs receive'. Because, we already check if the local pool
+		 * has SPA_FEATURE_LONGNAME enabled in dmu_recv_begin_check().
+		 */
+		if (source == ZPROP_SRC_RECEIVED) {
+			cmn_err(CE_NOTE, "Skipping ZFS_PROP_LONGNAME checks "
+			    "for dsname=%s\n", dsname);
+			err = -1;
+			break;
+		}
+
+		if ((err = zfsvfs_hold(dsname, FTAG, &zfsvfs, B_FALSE)) != 0) {
+			cmn_err(CE_WARN, "%s:%d Failed to hold for dsname=%s "
+			    "err=%d\n", __FILE__, __LINE__, dsname, err);
+			break;
+		}
+
+		if (!spa_feature_is_enabled(zfsvfs->z_os->os_spa,
+		    SPA_FEATURE_LONGNAME)) {
+			err = ENOTSUP;
+		} else {
+			/*
+			 * Set err to -1 to force the zfs_set_prop_nvlist code
+			 * down the default path to set the value in the nvlist.
+			 */
+			err = -1;
+		}
+		zfsvfs_rele(zfsvfs, FTAG);
+		break;
+	}
 	default:
 		err = -1;
 	}
diff --git a/module/zfs/zfs_znode.c b/module/zfs/zfs_znode.c
index 2e28587c8b95..824db8c689a7 100644
--- a/module/zfs/zfs_znode.c
+++ b/module/zfs/zfs_znode.c
@@ -178,6 +178,7 @@ zfs_obj_to_path_impl(objset_t *osp, uint64_t obj, sa_handle_t *hdl,
 	dmu_buf_t *prevdb = NULL;
 	dmu_buf_t *sa_db = NULL;
 	char *path = buf + len - 1;
+	char *comp_buf;
 	int error;
 
 	*path = '\0';
@@ -193,9 +194,10 @@ zfs_obj_to_path_impl(objset_t *osp, uint64_t obj, sa_handle_t *hdl,
 		return (error);
 	}
 
+	comp_buf = kmem_alloc(ZAP_MAXNAMELEN_NEW + 2, KM_SLEEP);
 	for (;;) {
 		uint64_t pobj = 0;
-		char component[MAXNAMELEN + 2];
+		char *component = comp_buf;
 		size_t complen;
 		int is_xattrdir = 0;
 
@@ -219,7 +221,8 @@ zfs_obj_to_path_impl(objset_t *osp, uint64_t obj, sa_handle_t *hdl,
 			strcpy(component + 1, "<xattrdir>");
 		} else {
 			error = zap_value_search(osp, pobj, obj,
-			    ZFS_DIRENT_OBJ(-1ULL), component + 1);
+			    ZFS_DIRENT_OBJ(-1ULL), component + 1,
+			    ZAP_MAXNAMELEN_NEW);
 			if (error != 0)
 				break;
 		}
@@ -250,6 +253,7 @@ zfs_obj_to_path_impl(objset_t *osp, uint64_t obj, sa_handle_t *hdl,
 	if (error == 0)
 		(void) memmove(buf, path, buf + len - path);
 
+	kmem_free(comp_buf, ZAP_MAXNAMELEN_NEW +2);
 	return (error);
 }
 
diff --git a/tests/runfiles/linux.run b/tests/runfiles/linux.run
index d791ce57c3fe..21ea7fd3b0af 100644
--- a/tests/runfiles/linux.run
+++ b/tests/runfiles/linux.run
@@ -142,6 +142,10 @@ pre =
 post =
 tags = ['functional', 'largest_pool']
 
+[tests/functional/longname:Linux]
+tests = ['longname_001_pos', 'longname_002_pos', 'longname_003_pos']
+tags = ['functional', 'longname']
+
 [tests/functional/mmap:Linux]
 tests = ['mmap_libaio_001_pos', 'mmap_sync_001_pos']
 tags = ['functional', 'mmap']
@@ -186,7 +190,7 @@ tests = ['renameat2_noreplace', 'renameat2_exchange', 'renameat2_whiteout']
 tags = ['functional', 'renameat2']
 
 [tests/functional/rsend:Linux]
-tests = ['send_realloc_dnode_size', 'send_encrypted_files']
+tests = ['send_realloc_dnode_size', 'send_encrypted_files', 'send-c_longname']
 tags = ['functional', 'rsend']
 
 [tests/functional/simd:Linux]
diff --git a/tests/zfs-tests/tests/Makefile.am b/tests/zfs-tests/tests/Makefile.am
index 131624c2e8ef..9dbd643a977f 100644
--- a/tests/zfs-tests/tests/Makefile.am
+++ b/tests/zfs-tests/tests/Makefile.am
@@ -1600,6 +1600,11 @@ nobase_dist_datadir_zfs_tests_tests_SCRIPTS += \
 	functional/link_count/link_count_001.ksh \
 	functional/link_count/link_count_root_inode.ksh \
 	functional/link_count/setup.ksh \
+	functional/longname/cleanup.ksh \
+	functional/longname/longname_001_pos.ksh \
+	functional/longname/longname_002_pos.ksh \
+	functional/longname/longname_003_pos.ksh \
+	functional/longname/setup.ksh \
 	functional/log_spacemap/log_spacemap_import_logs.ksh \
 	functional/migration/cleanup.ksh \
 	functional/migration/migration_001_pos.ksh \
@@ -1933,6 +1938,7 @@ nobase_dist_datadir_zfs_tests_tests_SCRIPTS += \
 	functional/rsend/rsend_031_pos.ksh \
 	functional/rsend/send-c_embedded_blocks.ksh \
 	functional/rsend/send-c_incremental.ksh \
+	functional/rsend/send-c_longname.ksh \
 	functional/rsend/send-c_lz4_disabled.ksh \
 	functional/rsend/send-c_mixed_compression.ksh \
 	functional/rsend/send-c_props.ksh \
diff --git a/tests/zfs-tests/tests/functional/cli_root/zpool_get/zpool_get.cfg b/tests/zfs-tests/tests/functional/cli_root/zpool_get/zpool_get.cfg
index 50c1b7a9d09e..b5bc46dce993 100644
--- a/tests/zfs-tests/tests/functional/cli_root/zpool_get/zpool_get.cfg
+++ b/tests/zfs-tests/tests/functional/cli_root/zpool_get/zpool_get.cfg
@@ -110,5 +110,6 @@ if is_linux || is_freebsd; then
 	    "feature@vdev_zaps_v2"
 	    "feature@raidz_expansion"
 	    "feature@fast_dedup"
+	    "feature@longname"
 	)
 fi
diff --git a/tests/zfs-tests/tests/functional/longname/cleanup.ksh b/tests/zfs-tests/tests/functional/longname/cleanup.ksh
new file mode 100755
index 000000000000..aac8062ec408
--- /dev/null
+++ b/tests/zfs-tests/tests/functional/longname/cleanup.ksh
@@ -0,0 +1,34 @@
+#!/bin/ksh -p
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or http://www.opensolaris.org/os/licensing.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
+# Use is subject to license terms.
+#
+
+#
+# Copyright (c) 2021 by Nutanix. All rights reserved.
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+default_cleanup
diff --git a/tests/zfs-tests/tests/functional/longname/longname_001_pos.ksh b/tests/zfs-tests/tests/functional/longname/longname_001_pos.ksh
new file mode 100755
index 000000000000..b7010fe0fc81
--- /dev/null
+++ b/tests/zfs-tests/tests/functional/longname/longname_001_pos.ksh
@@ -0,0 +1,132 @@
+#! /bin/ksh -p
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or http://www.opensolaris.org/os/licensing.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright (c) 2021 by Nutanix. All rights reserved.
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+#
+# DESCRIPTION:
+# Verify the support for long filenames.
+#
+# STRATEGY:
+# 0.  On a fresh dataset ensure property "longname" is enabled by default.
+# 1.  Disable the longname.
+# 2.  Try to create a filename whose length is > 256 bytes. This should fail.
+# 3.  Enable "longname" property on the dataset.
+# 4.  Try to create files and dirs whose names are > 256 bytes.
+# 5.  Ensure that "ls" is able to list the file.
+# 6.  Ensure stat(1) is able to stat the file/directory.
+# 7.  Try to rename the files and directories
+# 8.  Try to delete the files and directories
+
+verify_runnable "global"
+
+WORKDIR=$TESTDIR/workdir
+MOVEDIR=$TESTDIR/movedir/level2/level3/level4/level5/level6
+
+function cleanup
+{
+        log_must rm -rf $WORKDIR
+        log_must rm -rf $TESTDIR/movedir
+}
+
+LONGNAME=$(printf 'a%.0s' {1..512})
+LONGFNAME="file-$LONGNAME"
+LONGDNAME="dir-$LONGNAME"
+LONGPNAME="mypipe-$LONGNAME"
+LONGCNAME="char_dev-$LONGNAME"
+LONGLNAME="link-$LONGNAME"
+LONGNAME_255=$(printf 'a%.0s' {1..255})
+LONGNAME_1023=$(printf 'a%.0s' {1..1023})
+
+
+log_assert "Check longname support for directories/files"
+
+log_onexit cleanup
+
+log_must mkdir $WORKDIR
+log_must mkdir -p $MOVEDIR
+
+# Disable longname support
+log_must zfs set longname=off $TESTPOOL/$TESTFS
+
+#Ensure a file of length 255bytes can be created
+log_must touch $WORKDIR/$LONGNAME_255
+
+#Where as file of length 256bytes should fail
+log_mustnot touch $WORKDIR/${LONGNAME_255}b
+
+# Try to create a file with long name with property "longname=off"
+log_mustnot touch $WORKDIR/$LONGFNAME
+log_mustnot mkdir $WORKDIR/$LONGDNAME
+
+# Enable longname support
+log_must zfs set longname=on $TESTPOOL/$TESTFS
+
+# Retry the longname creates and that should succeed
+log_must mkdir $WORKDIR/$LONGDNAME
+log_must touch $WORKDIR/$LONGFNAME
+
+# Should be able to create a file with name of 1023 chars
+log_must touch $WORKDIR/$LONGNAME_1023
+
+# And names longer that 1023 should fail
+log_mustnot touch $WORKDIR/${LONGNAME_1023}b
+
+# Ensure the longnamed dir/file can be listed.
+name=$(ls $WORKDIR/$LONGFNAME)
+if [[ "${name}" != "$WORKDIR/$LONGFNAME" ]]; then
+        log_fail "Unable to list: $WORKDIR/$LONGFNAME ret:$name"
+fi
+
+name=$(ls -d $WORKDIR/$LONGDNAME)
+if [[ "${name}" != "$WORKDIR/$LONGDNAME" ]]; then
+        log_fail "Unable to list: $WORKDIR/$LONGDNAME ret:$name"
+fi
+
+# Ensure stat works
+log_must stat $WORKDIR/$LONGFNAME
+log_must stat $WORKDIR/$LONGDNAME
+
+# Ensure softlinks can be created from a longname to
+# another longnamed file.
+log_must ln -s $WORKDIR/$LONGFNAME $WORKDIR/$LONGLNAME
+
+# Ensure a longnamed pipe and character device file
+# can be created
+log_must mknod $WORKDIR/$LONGPNAME p
+log_must mknod $WORKDIR/$LONGCNAME c 92 1
+
+# Ensure we can rename the longname file
+log_must mv $WORKDIR/$LONGFNAME $WORKDIR/file2
+
+# Delete the long named dir/file
+log_must rmdir $WORKDIR/$LONGDNAME
+log_must rm $WORKDIR/file2
+log_must rm $WORKDIR/$LONGPNAME
+log_must rm $WORKDIR/$LONGCNAME
+log_must rm $WORKDIR/$LONGLNAME
+
+log_pass
diff --git a/tests/zfs-tests/tests/functional/longname/longname_002_pos.ksh b/tests/zfs-tests/tests/functional/longname/longname_002_pos.ksh
new file mode 100755
index 000000000000..dd2acabb3e02
--- /dev/null
+++ b/tests/zfs-tests/tests/functional/longname/longname_002_pos.ksh
@@ -0,0 +1,115 @@
+#! /bin/ksh -p
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or http://www.opensolaris.org/os/licensing.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright (c) 2021 by Nutanix. All rights reserved.
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+#
+# DESCRIPTION:
+# Check if longname feature is disabled by default and can be enabled.
+#
+# STRATEGY:
+# 1. Create a zpool with longname feature disabled
+# 2. Attempt to enable 'longname' property should fail.
+# 3. Attempt to create a longnamed (>255) file should fail.
+# 4. Enable the feature@longname
+# 5. Enable 'longname' property on the dataset.
+# 6. Should be able to create long named files and directories.
+# 7. Should be able to disable longname property.
+# 8. This should disallow creating new longnamed file/dirs. But, should be
+#    able to access existing longnamed files/dirs.
+verify_runnable "global"
+
+function cleanup
+{
+        log_must rm -rf $WORKDIR
+        poolexists $TESTPOOL && zpool destroy $TESTPOOL
+}
+
+log_assert "Check feature@longname and 'longname' dataset propery work correctly"
+
+log_onexit cleanup
+
+log_must zpool destroy $TESTPOOL
+
+log_must zpool create -o feature@longname=disabled $TESTPOOL $DISKS
+
+log_must zfs create $TESTPOOL/$TESTFS2
+
+log_must zfs set mountpoint=$TESTDIR2 $TESTPOOL/$TESTFS2
+
+log_mustnot zfs set longname=on $TESTPOOL/$TESTFS2
+
+LONGNAME=$(printf 'a%.0s' {1..512})
+LONGFNAME="file-$LONGNAME"
+LONGDNAME="dir-$LONGNAME"
+SHORTDNAME="dir-short"
+SHORTFNAME="file-short"
+WORKDIR=$TESTDIR2/workdir
+
+log_must mkdir $WORKDIR
+log_mustnot touch $WORKDIR/$LONGFNAME
+log_mustnot mkdir $WORKDIR/$LONGDNAME
+
+log_must zpool set feature@longname=enabled $TESTPOOL
+log_must zfs set longname=on $TESTPOOL/$TESTFS2
+
+log_must mkdir $WORKDIR/$LONGDNAME
+log_must touch $WORKDIR/$LONGFNAME
+
+# Ensure the above changes are synced out.
+log_must zpool sync $TESTPOOL
+
+# Ensure that the feature is activated once longnamed files are created.
+state=$(zpool get feature@longname -H -o value $TESTPOOL)
+log_note "feature@longname on pool: $TESTPOOL : $state"
+
+if [[ "$state" != "active" ]]; then
+	log_fail "feature@longname has state $state (expected active)"
+fi
+
+# Set longname=off.
+log_must zfs set longname=off $TESTPOOL/$TESTFS2
+
+# Ensure no new file/directory with longnames can be created or can be renamed
+# to.
+log_mustnot mkdir $WORKDIR/${LONGDNAME}.1
+log_mustnot touch $WORKDIR/${LONGFNAME}.1
+log_must mkdir $WORKDIR/$SHORTDNAME
+log_mustnot mv $WORKDIR/$SHORTDNAME $WORKDIR/${LONGDNAME}.1
+log_must touch $WORKDIR/$SHORTFNAME
+log_mustnot mv $WORKDIR/$SHORTFNAME $WORKDIR/${LONGFNAME}.1
+
+#Cleanup shortnames
+log_must rmdir $WORKDIR/$SHORTDNAME
+log_must rm $WORKDIR/$SHORTFNAME
+
+# But, should be able to stat and rename existing files
+log_must stat $WORKDIR/$LONGDNAME
+log_must stat $WORKDIR/$LONGFNAME
+log_must mv $WORKDIR/$LONGDNAME $WORKDIR/$SHORTDNAME
+log_must mv $WORKDIR/$LONGFNAME $WORKDIR/$SHORTFNAME
+
+log_pass
diff --git a/tests/zfs-tests/tests/functional/longname/longname_003_pos.ksh b/tests/zfs-tests/tests/functional/longname/longname_003_pos.ksh
new file mode 100755
index 000000000000..f684b514399d
--- /dev/null
+++ b/tests/zfs-tests/tests/functional/longname/longname_003_pos.ksh
@@ -0,0 +1,113 @@
+#! /bin/ksh -p
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or http://www.opensolaris.org/os/licensing.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright (c) 2021 by Nutanix. All rights reserved.
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+#
+# DESCRIPTION:
+# Check if longnames are handled correctly by ZIL replay and feature is activated.
+#
+# STRATEGY:
+# 1. Create a zpool with longname feature disabled
+# 2. Enable the feature@longname
+# 3. Enable 'longname' property on the dataset.
+# 4. Freeze the zpool
+# 5. Create a longname
+# 6. Export and import the zpool.
+# 7. Replaying of longname create should activate the feature@longname
+verify_runnable "global"
+
+function cleanup
+{
+	log_must rm -rf $WORKDIR
+	poolexists $TESTPOOL && zpool destroy $TESTPOOL
+}
+
+log_assert "Check feature@longname and 'longname' dataset propery work correctly"
+
+log_onexit cleanup
+
+poolexists $TESTPOOL && zpool destroy $TESTPOOL
+
+log_must zpool create -o feature@longname=disabled $TESTPOOL $DISKS
+
+log_must zfs create $TESTPOOL/$TESTFS
+
+log_must zfs set mountpoint=$TESTDIR $TESTPOOL/$TESTFS
+
+LONGNAME=$(printf 'a%.0s' {1..512})
+LONGFNAME="file-$LONGNAME"
+LONGDNAME="dir-$LONGNAME"
+SHORTDNAME="dir-short"
+SHORTFNAME="file-short"
+WORKDIR=$TESTDIR/workdir
+
+log_must mkdir $WORKDIR
+
+log_must zpool set feature@longname=enabled $TESTPOOL
+log_must zfs set longname=on $TESTPOOL/$TESTFS
+
+# Ensure that the feature is NOT activated yet as no longnamed file is created.
+state=$(zpool get feature@longname -H -o value $TESTPOOL)
+log_note "feature@longname on pool: $TESTPOOL : $state"
+
+if [[ "$state" != "enabled" ]]; then
+	log_fail "feature@longname has state $state (expected enabled)"
+fi
+
+#
+# This dd command works around an issue where ZIL records aren't created
+# after freezing the pool unless a ZIL header already exists. Create a file
+# synchronously to force ZFS to write one out.
+#
+log_must dd if=/dev/zero of=/$WORKDIR/sync conv=fdatasync,fsync bs=1 count=1
+
+log_must zpool freeze $TESTPOOL
+
+log_must mkdir $WORKDIR/$LONGDNAME
+log_must touch $WORKDIR/$LONGFNAME
+
+# Export and re-import the zpool
+log_must zpool export $TESTPOOL
+log_must zpool import $TESTPOOL
+
+# Ensure that the feature is activated once longnamed files are created.
+state=$(zpool get feature@longname -H -o value $TESTPOOL)
+log_note "feature@longname on pool: $TESTPOOL : $state"
+if [[ "$state" != "active" ]]; then
+	log_fail "feature@longname has state $state (expected active)"
+fi
+
+# Destroying the dataset where the feature is activated should put the feature
+# back to 'enabled' state
+log_must zfs destroy -r $TESTPOOL/$TESTFS
+state=$(zpool get feature@longname -H -o value $TESTPOOL)
+log_note "feature@longname on pool: $TESTPOOL : $state"
+if [[ "$state" != "enabled" ]]; then
+	log_fail "feature@longname has state $state (expected active)"
+fi
+
+log_pass
diff --git a/tests/zfs-tests/tests/functional/longname/setup.ksh b/tests/zfs-tests/tests/functional/longname/setup.ksh
new file mode 100755
index 000000000000..3f6759469b7b
--- /dev/null
+++ b/tests/zfs-tests/tests/functional/longname/setup.ksh
@@ -0,0 +1,35 @@
+#!/bin/ksh -p
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or http://www.opensolaris.org/os/licensing.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
+# Use is subject to license terms.
+#
+
+#
+# Copyright (c) 2021 by Nutanix. All rights reserved.
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+DISK=${DISKS%% *}
+default_setup $DISK
diff --git a/tests/zfs-tests/tests/functional/rsend/rsend.kshlib b/tests/zfs-tests/tests/functional/rsend/rsend.kshlib
index 80badd27331a..4931fabf7492 100644
--- a/tests/zfs-tests/tests/functional/rsend/rsend.kshlib
+++ b/tests/zfs-tests/tests/functional/rsend/rsend.kshlib
@@ -713,6 +713,7 @@ function stream_has_features
 	feature[resuming]="100000"
 	feature[redacted]="200000"
 	feature[compressed]="400000"
+	feature[longname]="10000000"
 
 	typeset flag known derived=0
 	for flag in "$@"; do
diff --git a/tests/zfs-tests/tests/functional/rsend/send-c_longname.ksh b/tests/zfs-tests/tests/functional/rsend/send-c_longname.ksh
new file mode 100755
index 000000000000..3f7edc6810dd
--- /dev/null
+++ b/tests/zfs-tests/tests/functional/rsend/send-c_longname.ksh
@@ -0,0 +1,98 @@
+#!/bin/ksh -p
+
+#
+# This file and its contents are supplied under the terms of the
+# Common Development and Distribution License ("CDDL"), version 1.0.
+# You may only use this file in accordance with the terms of version
+# 1.0 of the CDDL.
+#
+# A full copy of the text of the CDDL should have accompanied this
+# source.  A copy of the CDDL is also available via the Internet at
+# http://www.illumos.org/license/CDDL.
+#
+
+#
+# Copyright (c) 2021 by Nutanix. All rights reserved.
+#
+
+. $STF_SUITE/tests/functional/rsend/rsend.kshlib
+. $STF_SUITE/include/properties.shlib
+
+#
+# Description:
+# Verify that longname featureflag is present in the stream.
+#
+# Strategy:
+# 1. Create a filesystem with longnamed files/directories.
+# 2. Verify that the sendstream has the longname featureflag is present in the
+#    send stream.
+# 3. Verify the created streams can be received correctly.
+# 4. Verify that the longnamed files/directories are present in the received
+#    filesystem.
+#
+
+verify_runnable "both"
+
+log_assert "Verify that longnames are handled correctly in send stream."
+log_onexit cleanup_pool $POOL $POOL2 $POOL3
+
+typeset sendfs=$POOL/sendfs
+typeset recvfs=$POOL2/recvfs
+typeset recvfs3=$POOL3/recvfs
+typeset stream=$BACKDIR/stream
+typeset dump=$BACKDIR/dump
+
+log_must zfs create -o longname=on $sendfs
+typeset dir=$(get_prop mountpoint $sendfs)
+
+# Create a longnamed dir and a file in the send dataset
+LONGNAME=$(printf 'a%.0s' {1..512})
+LONGFNAME="file-$LONGNAME"
+LONGDNAME="dir-$LONGNAME"
+log_must mkdir $dir/$LONGDNAME
+log_must touch $dir/$LONGFNAME
+
+# When POOL3 is created by rsend.kshlib feature@longname is 'enabled'.
+# Recreate the POOL3 with feature@longname disabled.
+datasetexists $POOL3 && log_must zpool destroy $POOL3
+log_must zpool create -o feature@longname=disabled $POOL3 $DISK3
+
+# Generate the streams and zstreamdump output.
+log_must zfs snapshot $sendfs@now
+log_must eval "zfs send -p $sendfs@now >$stream"
+log_must eval "zstream dump -v <$stream >$dump"
+log_must eval "zfs recv $recvfs <$stream"
+cmp_ds_cont $sendfs $recvfs
+log_must stream_has_features $stream longname
+
+# Ensure the the receiving pool has feature@longname activated after receiving.
+feat_val=$(zpool get -H -o value feature@longname $POOL2)
+log_note "Zpool $POOL2 feature@longname=$feat_val"
+if [[ "$feat_val" != "active" ]]; then
+	log_fail "pool $POOL2 feature@longname=$feat_val (expected 'active')"
+fi
+
+# Receiving of the stream on $POOL3 should fail as longname is not enabled
+log_mustnot eval "zfs recv $recvfs3 <$stream"
+
+# Enable feature@longname and retry the receiving the stream.
+# It should succeed this time.
+log_must eval "zpool set feature@longname=enabled $POOL3"
+log_must eval "zfs recv $recvfs3 <$stream"
+
+log_must zfs get longname $recvfs3
+prop_val=$(zfs get -H -o value longname $recvfs3)
+log_note "dataset $recvfs3 has longname=$prop_val"
+if [[ "$prop_val" != "on" ]]; then
+	log_fail "$recvfs3 has longname=$prop_val (expected 'on')"
+fi
+
+#
+# TODO:
+# - Add a testcase to cover the case where send-stream does not contain
+#   properties (generated without "-p").
+#   In this case the target dataset would have longname files/directories which
+#   cannot be accessed if the dataset property 'longname=off'.
+#
+
+log_pass "Longnames are handled correctly in send/recv"