d/freebsd-nq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
3c3d7c8a57
freebsd-nq/include/libzfs_impl.h
George Wilson c15d36c674
Remove dependency on sharetab file and refactor sharing logic 
== Motivation and Context

The current implementation of 'sharenfs' and 'sharesmb' relies on
the use of the sharetab file. The use of this file is os-specific
and not required by linux or freebsd. Currently the code must
maintain updates to this file which adds complexity and presents
a significant performance impact when sharing many datasets. In
addition, concurrently running 'zfs sharenfs' command results in
missing entries in the sharetab file leading to unexpected failures.

== Description

This change removes the sharetab logic from the linux and freebsd
implementation of 'sharenfs' and 'sharesmb'. It still preserves an
os-specific library which contains the logic required for sharing
NFS or SMB. The following entry points exist in the vastly simplified
libshare library:

- sa_enable_share -- shares a dataset but may not commit the change
- sa_disable_share -- unshares a dataset but may not commit the change
- sa_is_shared -- determine if a dataset is shared
- sa_commit_share -- notify NFS/SMB subsystem to commit the shares
- sa_validate_shareopts -- determine if sharing options are valid

The sa_commit_share entry point is provided as a performance enhancement
and is not required. The sa_enable_share/sa_disable_share may commit
the share as part of the implementation. Libshare provides a framework
for both NFS and SMB but some operating systems may not fully support
these protocols or all features of the protocol.

NFS Operation:
For linux, libshare updates /etc/exports.d/zfs.exports to add
and remove shares and then commits the changes by invoking
'exportfs -r'. This file, is automatically read by the kernel NFS
implementation which makes for better integration with the NFS systemd
service. For FreeBSD, libshare updates /etc/zfs/exports to add and
remove shares and then commits the changes by sending a SIGHUP to
mountd.

SMB Operation:
For linux, libshare adds and removes files in /var/lib/samba/usershares
by calling the 'net' command directly. There is no need to commit the
changes. FreeBSD does not support SMB.

== Performance Results

To test sharing performance we created a pool with an increasing number
of datasets and invoked various zfs actions that would enable and
disable sharing. The performance testing was limited to NFS sharing.
The following tests were performed on an 8 vCPU system with 128GB and
a pool comprised of 4 50GB SSDs:

Scale testing:
- Share all filesystems in parallel -- zfs sharenfs=on <dataset> &
- Unshare all filesystems in parallel -- zfs sharenfs=off <dataset> &

Functional testing:
- share each filesystem serially -- zfs share -a
- unshare each filesystem serially -- zfs unshare -a
- reset sharenfs property and unshare -- zfs inherit -r sharenfs <pool>

For 'zfs sharenfs=on' scale testing we saw an average reduction in time
of 89.43% and for 'zfs sharenfs=off' we saw an average reduction in time
of 83.36%.

Functional testing also shows a huge improvement:
- zfs share -- 97.97% reduction in time
- zfs unshare -- 96.47% reduction in time
- zfs inhert -r sharenfs -- 99.01% reduction in time

Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Bryant G. Ly <bryangly@gmail.com>
Signed-off-by: George Wilson <gwilson@delphix.com>
External-Issue: DLPX-68690
Closes #1603
Closes #7692
Closes #7943
Closes #10300
2020-07-13 09:19:18 -07:00

262 lines
7.9 KiB
C
Raw Blame History

/*
* 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) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2011, 2020 by Delphix. All rights reserved.
* Copyright (c) 2018 Datto Inc.
* Copyright 2020 Joyent, Inc.
*/
#ifndef _LIBZFS_IMPL_H
#define _LIBZFS_IMPL_H
#include <sys/fs/zfs.h>
#include <sys/spa.h>
#include <sys/nvpair.h>
#include <sys/dmu.h>
#include <sys/zfs_ioctl.h>
#include <regex.h>
#include <libuutil.h>
#include <libzfs.h>
#include <libshare.h>
#include <libzfs_core.h>
#ifdef __cplusplus
extern "C" {
#endif
struct libzfs_handle {
int libzfs_error;
int libzfs_fd;
FILE *libzfs_mnttab;
zpool_handle_t *libzfs_pool_handles;
uu_avl_pool_t *libzfs_ns_avlpool;
uu_avl_t *libzfs_ns_avl;
uint64_t libzfs_ns_gen;
int libzfs_desc_active;
char libzfs_action[1024];
char libzfs_desc[1024];
int libzfs_printerr;
int libzfs_storeerr; /* stuff error messages into buffer */
boolean_t libzfs_mnttab_enable;
/*
* We need a lock to handle the case where parallel mount
* threads are populating the mnttab cache simultaneously. The
* lock only protects the integrity of the avl tree, and does
* not protect the contents of the mnttab entries themselves.
*/
pthread_mutex_t libzfs_mnttab_cache_lock;
avl_tree_t libzfs_mnttab_cache;
int libzfs_pool_iter;
char libzfs_chassis_id[256];
boolean_t libzfs_prop_debug;
regex_t libzfs_urire;
};
struct zfs_handle {
libzfs_handle_t *zfs_hdl;
zpool_handle_t *zpool_hdl;
char zfs_name[ZFS_MAX_DATASET_NAME_LEN];
zfs_type_t zfs_type; /* type including snapshot */
zfs_type_t zfs_head_type; /* type excluding snapshot */
dmu_objset_stats_t zfs_dmustats;
nvlist_t *zfs_props;
nvlist_t *zfs_user_props;
nvlist_t *zfs_recvd_props;
boolean_t zfs_mntcheck;
char *zfs_mntopts;
uint8_t *zfs_props_table;
};
/*
* This is different from checking zfs_type, because it will also catch
* snapshots of volumes.
*/
#define ZFS_IS_VOLUME(zhp) ((zhp)->zfs_head_type == ZFS_TYPE_VOLUME)
struct zpool_handle {
libzfs_handle_t *zpool_hdl;
zpool_handle_t *zpool_next;
char zpool_name[ZFS_MAX_DATASET_NAME_LEN];
int zpool_state;
size_t zpool_config_size;
nvlist_t *zpool_config;
nvlist_t *zpool_old_config;
nvlist_t *zpool_props;
diskaddr_t zpool_start_block;
};
typedef enum {
PROTO_NFS = 0,
PROTO_SMB = 1,
PROTO_END = 2
} zfs_share_proto_t;
/*
* The following can be used as a bitmask and any new values
* added must preserve that capability.
*/
typedef enum {
SHARED_NOT_SHARED = 0x0,
SHARED_NFS = 0x2,
SHARED_SMB = 0x4
} zfs_share_type_t;
typedef int (*zfs_uri_handler_fn_t)(struct libzfs_handle *, const char *,
const char *, zfs_keyformat_t, boolean_t, uint8_t **, size_t *);
typedef struct zfs_uri_handler {
const char *zuh_scheme;
zfs_uri_handler_fn_t zuh_handler;
} zfs_uri_handler_t;
#define CONFIG_BUF_MINSIZE 262144
int zfs_error(libzfs_handle_t *, int, const char *);
int zfs_error_fmt(libzfs_handle_t *, int, const char *, ...);
void zfs_error_aux(libzfs_handle_t *, const char *, ...);
void *zfs_alloc(libzfs_handle_t *, size_t);
void *zfs_realloc(libzfs_handle_t *, void *, size_t, size_t);
char *zfs_asprintf(libzfs_handle_t *, const char *, ...);
char *zfs_strdup(libzfs_handle_t *, const char *);
int no_memory(libzfs_handle_t *);
int zfs_standard_error(libzfs_handle_t *, int, const char *);
int zfs_standard_error_fmt(libzfs_handle_t *, int, const char *, ...);
void zfs_setprop_error(libzfs_handle_t *, zfs_prop_t, int, char *);
int zpool_standard_error(libzfs_handle_t *, int, const char *);
int zpool_standard_error_fmt(libzfs_handle_t *, int, const char *, ...);
zfs_handle_t *make_dataset_handle_zc(libzfs_handle_t *, zfs_cmd_t *);
zfs_handle_t *make_dataset_simple_handle_zc(zfs_handle_t *, zfs_cmd_t *);
int zprop_parse_value(libzfs_handle_t *, nvpair_t *, int, zfs_type_t,
nvlist_t *, char **, uint64_t *, const char *);
int zprop_expand_list(libzfs_handle_t *hdl, zprop_list_t **plp,
zfs_type_t type);
/*
* Use this changelist_gather() flag to force attempting mounts
* on each change node regardless of whether or not it is currently
* mounted.
*/
#define CL_GATHER_MOUNT_ALWAYS 1
/*
* changelist_gather() flag to force it to iterate on mounted datasets only
*/
#define CL_GATHER_ITER_MOUNTED 2
typedef struct prop_changelist prop_changelist_t;
int zcmd_alloc_dst_nvlist(libzfs_handle_t *, zfs_cmd_t *, size_t);
int zcmd_write_src_nvlist(libzfs_handle_t *, zfs_cmd_t *, nvlist_t *);
int zcmd_write_conf_nvlist(libzfs_handle_t *, zfs_cmd_t *, nvlist_t *);
int zcmd_expand_dst_nvlist(libzfs_handle_t *, zfs_cmd_t *);
int zcmd_read_dst_nvlist(libzfs_handle_t *, zfs_cmd_t *, nvlist_t **);
void zcmd_free_nvlists(zfs_cmd_t *);
int changelist_prefix(prop_changelist_t *);
int changelist_postfix(prop_changelist_t *);
void changelist_rename(prop_changelist_t *, const char *, const char *);
void changelist_remove(prop_changelist_t *, const char *);
void changelist_free(prop_changelist_t *);
prop_changelist_t *changelist_gather(zfs_handle_t *, zfs_prop_t, int, int);
int changelist_unshare(prop_changelist_t *, zfs_share_proto_t *);
int changelist_haszonedchild(prop_changelist_t *);
void remove_mountpoint(zfs_handle_t *);
int create_parents(libzfs_handle_t *, char *, int);
boolean_t isa_child_of(const char *dataset, const char *parent);
zfs_handle_t *make_dataset_handle(libzfs_handle_t *, const char *);
zfs_handle_t *make_bookmark_handle(zfs_handle_t *, const char *,
nvlist_t *props);
int zpool_open_silent(libzfs_handle_t *, const char *, zpool_handle_t **);
boolean_t zpool_name_valid(libzfs_handle_t *, boolean_t, const char *);
int zfs_validate_name(libzfs_handle_t *hdl, const char *path, int type,
boolean_t modifying);
void namespace_clear(libzfs_handle_t *);
extern int zfs_parse_options(char *, zfs_share_proto_t);
extern int zfs_unshare_proto(zfs_handle_t *,
const char *, zfs_share_proto_t *);
typedef struct {
zfs_prop_t p_prop;
char *p_name;
int p_share_err;
int p_unshare_err;
} proto_table_t;
typedef struct differ_info {
zfs_handle_t *zhp;
char *fromsnap;
char *frommnt;
char *tosnap;
char *tomnt;
char *ds;
char *dsmnt;
char *tmpsnap;
char errbuf[1024];
boolean_t isclone;
boolean_t scripted;
boolean_t classify;
boolean_t timestamped;
uint64_t shares;
int zerr;
int cleanupfd;
int outputfd;
int datafd;
} differ_info_t;
extern proto_table_t proto_table[PROTO_END];
extern int do_mount(zfs_handle_t *zhp, const char *mntpt, char *opts,
int flags);
extern int do_unmount(const char *mntpt, int flags);
extern int zfs_mount_delegation_check(void);
extern int zfs_share_proto(zfs_handle_t *zhp, zfs_share_proto_t *proto);
extern int unshare_one(libzfs_handle_t *hdl, const char *name,
const char *mountpoint, zfs_share_proto_t proto);
extern boolean_t zfs_is_mountable(zfs_handle_t *zhp, char *buf, size_t buflen,
zprop_source_t *source, int flags);
extern zfs_share_type_t is_shared(const char *mountpoint,
zfs_share_proto_t proto);
extern int libzfs_load_module(void);
extern int zpool_relabel_disk(libzfs_handle_t *hdl, const char *path,
const char *msg);
extern int find_shares_object(differ_info_t *di);
extern void libzfs_set_pipe_max(int infd);
extern void zfs_commit_proto(zfs_share_proto_t *);
#ifdef __cplusplus
}
#endif
#endif /* _LIBZFS_IMPL_H */
Reference in New Issue View Git Blame Copy Permalink