svn commit: r344569 - in head/cddl/contrib/opensolaris: cmd/zfs lib/libzfs/common
Baptiste Daroussin
bapt at FreeBSD.org
Tue Feb 26 08:18:37 UTC 2019
Author: bapt
Date: Tue Feb 26 08:18:34 2019
New Revision: 344569
URL: https://svnweb.freebsd.org/changeset/base/344569
Log:
Implement parallel mounting for ZFS filesystem
It was first implemented on Illumos and then ported to ZoL.
This patch is a port to FreeBSD of the ZoL version.
This patch also includes a fix for a race condition that was amended
With such patch Delphix has seen a huge decrease in latency of the mount phase
(https://github.com/openzfs/openzfs/commit/a3f0e2b569 for details).
With that current change Gandi has measured improvments that are on par with
those reported by Delphix.
Zol commits incorporated:
https://github.com/zfsonlinux/zfs/commit/a10d50f999511d304f910852c7825c70c9c9e303
https://github.com/zfsonlinux/zfs/commit/e63ac16d25fbe991a356489c86d4077567dfea21
Reviewed by: avg, sef
Approved by: avg, sef
Obtained from: ZoL
MFC after: 1 month
Relnotes: yes
Sponsored by: Gandi.net
Differential Revision: https://reviews.freebsd.org/D19098
Modified:
head/cddl/contrib/opensolaris/cmd/zfs/zfs_main.c
head/cddl/contrib/opensolaris/lib/libzfs/common/libzfs.h
head/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_dataset.c
head/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_impl.h
head/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c
Modified: head/cddl/contrib/opensolaris/cmd/zfs/zfs_main.c
==============================================================================
--- head/cddl/contrib/opensolaris/cmd/zfs/zfs_main.c Tue Feb 26 06:22:10 2019 (r344568)
+++ head/cddl/contrib/opensolaris/cmd/zfs/zfs_main.c Tue Feb 26 08:18:34 2019 (r344569)
@@ -5812,8 +5812,13 @@ zfs_do_holds(int argc, char **argv)
#define CHECK_SPINNER 30
#define SPINNER_TIME 3 /* seconds */
-#define MOUNT_TIME 5 /* seconds */
+#define MOUNT_TIME 1 /* seconds */
+typedef struct get_all_state {
+ boolean_t ga_verbose;
+ get_all_cb_t *ga_cbp;
+} get_all_state_t;
+
static int
get_one_dataset(zfs_handle_t *zhp, void *data)
{
@@ -5821,10 +5826,10 @@ get_one_dataset(zfs_handle_t *zhp, void *data)
static int spinval = 0;
static int spincheck = 0;
static time_t last_spin_time = (time_t)0;
- get_all_cb_t *cbp = data;
+ get_all_state_t *state = data;
zfs_type_t type = zfs_get_type(zhp);
- if (cbp->cb_verbose) {
+ if (state->ga_verbose) {
if (--spincheck < 0) {
time_t now = time(NULL);
if (last_spin_time + SPINNER_TIME < now) {
@@ -5850,26 +5855,24 @@ get_one_dataset(zfs_handle_t *zhp, void *data)
zfs_close(zhp);
return (0);
}
- libzfs_add_handle(cbp, zhp);
- assert(cbp->cb_used <= cbp->cb_alloc);
+ libzfs_add_handle(state->ga_cbp, zhp);
+ assert(state->ga_cbp->cb_used <= state->ga_cbp->cb_alloc);
return (0);
}
static void
-get_all_datasets(zfs_handle_t ***dslist, size_t *count, boolean_t verbose)
+get_all_datasets(get_all_cb_t *cbp, boolean_t verbose)
{
- get_all_cb_t cb = { 0 };
- cb.cb_verbose = verbose;
- cb.cb_getone = get_one_dataset;
+ get_all_state_t state = {
+ .ga_verbose = verbose,
+ .ga_cbp = cbp
+ };
if (verbose)
set_progress_header(gettext("Reading ZFS config"));
- (void) zfs_iter_root(g_zfs, get_one_dataset, &cb);
+ (void) zfs_iter_root(g_zfs, get_one_dataset, &state);
- *dslist = cb.cb_handles;
- *count = cb.cb_used;
-
if (verbose)
finish_progress(gettext("done."));
}
@@ -5879,9 +5882,20 @@ get_all_datasets(zfs_handle_t ***dslist, size_t *count
* similar, we have a common function with an extra parameter to determine which
* mode we are using.
*/
-#define OP_SHARE 0x1
-#define OP_MOUNT 0x2
+typedef enum { OP_SHARE, OP_MOUNT } share_mount_op_t;
+typedef struct share_mount_state {
+ share_mount_op_t sm_op;
+ boolean_t sm_verbose;
+ int sm_flags;
+ char *sm_options;
+ char *sm_proto; /* only valid for OP_SHARE */
+ pthread_mutex_t sm_lock; /* protects the remaining fields */
+ uint_t sm_total; /* number of filesystems to process */
+ uint_t sm_done; /* number of filesystems processed */
+ int sm_status; /* -1 if any of the share/mount operations failed */
+} share_mount_state_t;
+
/*
* Share or mount a dataset.
*/
@@ -6122,6 +6136,29 @@ report_mount_progress(int current, int total)
update_progress(info);
}
+/*
+ * zfs_foreach_mountpoint() callback that mounts or shares on filesystem and
+ * updates the progress meter
+ */
+static int
+share_mount_one_cb(zfs_handle_t *zhp, void *arg)
+{
+ share_mount_state_t *sms = arg;
+ int ret;
+
+ ret = share_mount_one(zhp, sms->sm_op, sms->sm_flags, sms->sm_proto,
+ B_FALSE, sms->sm_options);
+
+ pthread_mutex_lock(&sms->sm_lock);
+ if (ret != 0)
+ sms->sm_status = ret;
+ sms->sm_done++;
+ if (sms->sm_verbose)
+ report_mount_progress(sms->sm_done, sms->sm_total);
+ pthread_mutex_unlock(&sms->sm_lock);
+ return (ret);
+}
+
static void
append_options(char *mntopts, char *newopts)
{
@@ -6194,8 +6231,6 @@ share_mount(int op, int argc, char **argv)
/* check number of arguments */
if (do_all) {
- zfs_handle_t **dslist = NULL;
- size_t i, count = 0;
char *protocol = NULL;
if (op == OP_SHARE && argc > 0) {
@@ -6216,35 +6251,48 @@ share_mount(int op, int argc, char **argv)
}
start_progress_timer();
- get_all_datasets(&dslist, &count, verbose);
+ get_all_cb_t cb = { 0 };
+ get_all_datasets(&cb, verbose);
- if (count == 0)
+ if (cb.cb_used == 0) {
+ if (options != NULL)
+ free(options);
return (0);
+ }
- qsort(dslist, count, sizeof (void *), libzfs_dataset_cmp);
#ifdef illumos
- sa_init_selective_arg_t sharearg;
- sharearg.zhandle_arr = dslist;
- sharearg.zhandle_len = count;
- if ((ret = zfs_init_libshare_arg(zfs_get_handle(dslist[0]),
- SA_INIT_SHARE_API_SELECTIVE, &sharearg)) != SA_OK) {
- (void) fprintf(stderr,
- gettext("Could not initialize libshare, %d"), ret);
- return (ret);
+ if (op == OP_SHARE) {
+ sa_init_selective_arg_t sharearg;
+ sharearg.zhandle_arr = cb.cb_handles;
+ sharearg.zhandle_len = cb.cb_used;
+ if ((ret = zfs_init_libshare_arg(g_zfs,
+ SA_INIT_SHARE_API_SELECTIVE, &sharearg)) != SA_OK) {
+ (void) fprintf(stderr, gettext(
+ "Could not initialize libshare, %d"), ret);
+ return (ret);
+ }
}
#endif
+ share_mount_state_t share_mount_state = { 0 };
+ share_mount_state.sm_op = op;
+ share_mount_state.sm_verbose = verbose;
+ share_mount_state.sm_flags = flags;
+ share_mount_state.sm_options = options;
+ share_mount_state.sm_proto = protocol;
+ share_mount_state.sm_total = cb.cb_used;
+ pthread_mutex_init(&share_mount_state.sm_lock, NULL);
- for (i = 0; i < count; i++) {
- if (verbose)
- report_mount_progress(i, count);
+ /*
+ * libshare isn't mt-safe, so only do the operation in parallel
+ * if we're mounting.
+ */
+ zfs_foreach_mountpoint(g_zfs, cb.cb_handles, cb.cb_used,
+ share_mount_one_cb, &share_mount_state, op == OP_MOUNT);
+ ret = share_mount_state.sm_status;
- if (share_mount_one(dslist[i], op, flags, protocol,
- B_FALSE, options) != 0)
- ret = 1;
- zfs_close(dslist[i]);
- }
-
- free(dslist);
+ for (int i = 0; i < cb.cb_used; i++)
+ zfs_close(cb.cb_handles[i]);
+ free(cb.cb_handles);
} else if (argc == 0) {
struct mnttab entry;
Modified: head/cddl/contrib/opensolaris/lib/libzfs/common/libzfs.h
==============================================================================
--- head/cddl/contrib/opensolaris/lib/libzfs/common/libzfs.h Tue Feb 26 06:22:10 2019 (r344568)
+++ head/cddl/contrib/opensolaris/lib/libzfs/common/libzfs.h Tue Feb 26 08:18:34 2019 (r344569)
@@ -579,12 +579,12 @@ typedef struct get_all_cb {
zfs_handle_t **cb_handles;
size_t cb_alloc;
size_t cb_used;
- boolean_t cb_verbose;
- int (*cb_getone)(zfs_handle_t *, void *);
} get_all_cb_t;
+void zfs_foreach_mountpoint(libzfs_handle_t *, zfs_handle_t **, size_t,
+ zfs_iter_f, void*, boolean_t);
+
void libzfs_add_handle(get_all_cb_t *, zfs_handle_t *);
-int libzfs_dataset_cmp(const void *, const void *);
/*
* Functions to create and destroy datasets.
Modified: head/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_dataset.c
==============================================================================
--- head/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_dataset.c Tue Feb 26 06:22:10 2019 (r344568)
+++ head/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_dataset.c Tue Feb 26 08:18:34 2019 (r344569)
@@ -799,6 +799,7 @@ libzfs_mnttab_cache_compare(const void *arg1, const vo
void
libzfs_mnttab_init(libzfs_handle_t *hdl)
{
+ pthread_mutex_init(&hdl->libzfs_mnttab_cache_lock, NULL);
assert(avl_numnodes(&hdl->libzfs_mnttab_cache) == 0);
avl_create(&hdl->libzfs_mnttab_cache, libzfs_mnttab_cache_compare,
sizeof (mnttab_node_t), offsetof(mnttab_node_t, mtn_node));
@@ -839,6 +840,7 @@ libzfs_mnttab_fini(libzfs_handle_t *hdl)
free(mtn);
}
avl_destroy(&hdl->libzfs_mnttab_cache);
+ (void) pthread_mutex_destroy(&hdl->libzfs_mnttab_cache_lock);
}
void
@@ -853,6 +855,7 @@ libzfs_mnttab_find(libzfs_handle_t *hdl, const char *f
{
mnttab_node_t find;
mnttab_node_t *mtn;
+ int ret = ENOENT;
if (!hdl->libzfs_mnttab_enable) {
struct mnttab srch = { 0 };
@@ -868,6 +871,7 @@ libzfs_mnttab_find(libzfs_handle_t *hdl, const char *f
return (ENOENT);
}
+ pthread_mutex_lock(&hdl->libzfs_mnttab_cache_lock);
if (avl_numnodes(&hdl->libzfs_mnttab_cache) == 0)
libzfs_mnttab_update(hdl);
@@ -875,9 +879,10 @@ libzfs_mnttab_find(libzfs_handle_t *hdl, const char *f
mtn = avl_find(&hdl->libzfs_mnttab_cache, &find, NULL);
if (mtn) {
*entry = mtn->mtn_mt;
- return (0);
+ ret = 0;
}
- return (ENOENT);
+ pthread_mutex_unlock(&hdl->libzfs_mnttab_cache_lock);
+ return (ret);
}
void
@@ -886,15 +891,17 @@ libzfs_mnttab_add(libzfs_handle_t *hdl, const char *sp
{
mnttab_node_t *mtn;
- if (avl_numnodes(&hdl->libzfs_mnttab_cache) == 0)
- return;
- mtn = zfs_alloc(hdl, sizeof (mnttab_node_t));
- mtn->mtn_mt.mnt_special = zfs_strdup(hdl, special);
- mtn->mtn_mt.mnt_mountp = zfs_strdup(hdl, mountp);
- mtn->mtn_mt.mnt_fstype = zfs_strdup(hdl, MNTTYPE_ZFS);
- mtn->mtn_mt.mnt_mntopts = zfs_strdup(hdl, mntopts);
- avl_add(&hdl->libzfs_mnttab_cache, mtn);
-}
+ pthread_mutex_lock(&hdl->libzfs_mnttab_cache_lock);
+ if (avl_numnodes(&hdl->libzfs_mnttab_cache) == 0) {
+ mtn = zfs_alloc(hdl, sizeof (mnttab_node_t));
+ mtn->mtn_mt.mnt_special = zfs_strdup(hdl, special);
+ mtn->mtn_mt.mnt_mountp = zfs_strdup(hdl, mountp);
+ mtn->mtn_mt.mnt_fstype = zfs_strdup(hdl, MNTTYPE_ZFS);
+ mtn->mtn_mt.mnt_mntopts = zfs_strdup(hdl, mntopts);
+ avl_add(&hdl->libzfs_mnttab_cache, mtn);
+ }
+ pthread_mutex_unlock(&hdl->libzfs_mnttab_cache_lock);
+}
void
libzfs_mnttab_remove(libzfs_handle_t *hdl, const char *fsname)
@@ -902,6 +909,7 @@ libzfs_mnttab_remove(libzfs_handle_t *hdl, const char
mnttab_node_t find;
mnttab_node_t *ret;
+ pthread_mutex_lock(&hdl->libzfs_mnttab_cache_lock);
find.mtn_mt.mnt_special = (char *)fsname;
if ((ret = avl_find(&hdl->libzfs_mnttab_cache, (void *)&find, NULL))
!= NULL) {
@@ -912,6 +920,7 @@ libzfs_mnttab_remove(libzfs_handle_t *hdl, const char
free(ret->mtn_mt.mnt_mntopts);
free(ret);
}
+ pthread_mutex_unlock(&hdl->libzfs_mnttab_cache_lock);
}
int
Modified: head/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_impl.h
==============================================================================
--- head/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_impl.h Tue Feb 26 06:22:10 2019 (r344568)
+++ head/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_impl.h Tue Feb 26 08:18:34 2019 (r344569)
@@ -22,7 +22,7 @@
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2011 Pawel Jakub Dawidek. All rights reserved.
- * Copyright (c) 2011, 2016 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2017 by Delphix. All rights reserved.
* Copyright (c) 2013 Martin Matuska <mm at FreeBSD.org>. All rights reserved.
*/
@@ -73,6 +73,13 @@ struct libzfs_handle {
int libzfs_storeerr; /* stuff error messages into buffer */
void *libzfs_sharehdl; /* libshare handle */
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;
libzfs_fru_t **libzfs_fru_hash;
Modified: head/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c
==============================================================================
--- head/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c Tue Feb 26 06:22:10 2019 (r344568)
+++ head/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_mount.c Tue Feb 26 08:18:34 2019 (r344569)
@@ -26,6 +26,7 @@
* Copyright 2016 Igor Kozhukhov <ikozhukhov at gmail.com>
* Copyright 2017 Joyent, Inc.
* Copyright 2017 RackTop Systems.
+ * Copyright 2018 OmniOS Community Edition (OmniOSce) Association.
*/
/*
@@ -34,25 +35,25 @@
* they are used by mount and unmount and when changing a filesystem's
* mountpoint.
*
- * zfs_is_mounted()
- * zfs_mount()
- * zfs_unmount()
- * zfs_unmountall()
+ * zfs_is_mounted()
+ * zfs_mount()
+ * zfs_unmount()
+ * zfs_unmountall()
*
* This file also contains the functions used to manage sharing filesystems via
* NFS and iSCSI:
*
- * zfs_is_shared()
- * zfs_share()
- * zfs_unshare()
+ * zfs_is_shared()
+ * zfs_share()
+ * zfs_unshare()
*
- * zfs_is_shared_nfs()
- * zfs_is_shared_smb()
- * zfs_share_proto()
- * zfs_shareall();
- * zfs_unshare_nfs()
- * zfs_unshare_smb()
- * zfs_unshareall_nfs()
+ * zfs_is_shared_nfs()
+ * zfs_is_shared_smb()
+ * zfs_share_proto()
+ * zfs_shareall();
+ * zfs_unshare_nfs()
+ * zfs_unshare_smb()
+ * zfs_unshareall_nfs()
* zfs_unshareall_smb()
* zfs_unshareall()
* zfs_unshareall_bypath()
@@ -60,8 +61,8 @@
* The following functions are available for pool consumers, and will
* mount/unmount and share/unshare all datasets within pool:
*
- * zpool_enable_datasets()
- * zpool_disable_datasets()
+ * zpool_enable_datasets()
+ * zpool_disable_datasets()
*/
#include <dirent.h>
@@ -83,10 +84,14 @@
#include <libzfs.h>
#include "libzfs_impl.h"
+#include <thread_pool.h>
#include <libshare.h>
#define MAXISALEN 257 /* based on sysinfo(2) man page */
+static int mount_tp_nthr = 512; /* tpool threads for multi-threaded mounting */
+
+static void zfs_mount_task(void *);
static int zfs_share_proto(zfs_handle_t *, zfs_share_proto_t *);
zfs_share_type_t zfs_is_shared_proto(zfs_handle_t *, char **,
zfs_share_proto_t);
@@ -1134,25 +1139,32 @@ remove_mountpoint(zfs_handle_t *zhp)
}
}
+/*
+ * Add the given zfs handle to the cb_handles array, dynamically reallocating
+ * the array if it is out of space
+ */
void
libzfs_add_handle(get_all_cb_t *cbp, zfs_handle_t *zhp)
{
if (cbp->cb_alloc == cbp->cb_used) {
size_t newsz;
- void *ptr;
+ zfs_handle_t **newhandles;
- newsz = cbp->cb_alloc ? cbp->cb_alloc * 2 : 64;
- ptr = zfs_realloc(zhp->zfs_hdl,
- cbp->cb_handles, cbp->cb_alloc * sizeof (void *),
- newsz * sizeof (void *));
- cbp->cb_handles = ptr;
+ newsz = cbp->cb_alloc != 0 ? cbp->cb_alloc * 2 : 64;
+ newhandles = zfs_realloc(zhp->zfs_hdl,
+ cbp->cb_handles, cbp->cb_alloc * sizeof (zfs_handle_t *),
+ newsz * sizeof (zfs_handle_t *));
+ cbp->cb_handles = newhandles;
cbp->cb_alloc = newsz;
}
cbp->cb_handles[cbp->cb_used++] = zhp;
}
+/*
+ * Recursive helper function used during file system enumeration
+ */
static int
-mount_cb(zfs_handle_t *zhp, void *data)
+zfs_iter_cb(zfs_handle_t *zhp, void *data)
{
get_all_cb_t *cbp = data;
@@ -1178,104 +1190,362 @@ mount_cb(zfs_handle_t *zhp, void *data)
}
libzfs_add_handle(cbp, zhp);
- if (zfs_iter_filesystems(zhp, mount_cb, cbp) != 0) {
+ if (zfs_iter_filesystems(zhp, zfs_iter_cb, cbp) != 0) {
zfs_close(zhp);
return (-1);
}
return (0);
}
-int
-libzfs_dataset_cmp(const void *a, const void *b)
+/*
+ * Sort comparator that compares two mountpoint paths. We sort these paths so
+ * that subdirectories immediately follow their parents. This means that we
+ * effectively treat the '/' character as the lowest value non-nul char.
+ * Since filesystems from non-global zones can have the same mountpoint
+ * as other filesystems, the comparator sorts global zone filesystems to
+ * the top of the list. This means that the global zone will traverse the
+ * filesystem list in the correct order and can stop when it sees the
+ * first zoned filesystem. In a non-global zone, only the delegated
+ * filesystems are seen.
+ *
+ * An example sorted list using this comparator would look like:
+ *
+ * /foo
+ * /foo/bar
+ * /foo/bar/baz
+ * /foo/baz
+ * /foo.bar
+ * /foo (NGZ1)
+ * /foo (NGZ2)
+ *
+ * The mount code depend on this ordering to deterministically iterate
+ * over filesystems in order to spawn parallel mount tasks.
+ */
+static int
+mountpoint_cmp(const void *arga, const void *argb)
{
- zfs_handle_t **za = (zfs_handle_t **)a;
- zfs_handle_t **zb = (zfs_handle_t **)b;
+ zfs_handle_t *const *zap = arga;
+ zfs_handle_t *za = *zap;
+ zfs_handle_t *const *zbp = argb;
+ zfs_handle_t *zb = *zbp;
char mounta[MAXPATHLEN];
char mountb[MAXPATHLEN];
+ const char *a = mounta;
+ const char *b = mountb;
boolean_t gota, gotb;
+ uint64_t zoneda, zonedb;
- if ((gota = (zfs_get_type(*za) == ZFS_TYPE_FILESYSTEM)) != 0)
- verify(zfs_prop_get(*za, ZFS_PROP_MOUNTPOINT, mounta,
+ zoneda = zfs_prop_get_int(za, ZFS_PROP_ZONED);
+ zonedb = zfs_prop_get_int(zb, ZFS_PROP_ZONED);
+ if (zoneda && !zonedb)
+ return (1);
+ if (!zoneda && zonedb)
+ return (-1);
+ gota = (zfs_get_type(za) == ZFS_TYPE_FILESYSTEM);
+ if (gota)
+ verify(zfs_prop_get(za, ZFS_PROP_MOUNTPOINT, mounta,
sizeof (mounta), NULL, NULL, 0, B_FALSE) == 0);
- if ((gotb = (zfs_get_type(*zb) == ZFS_TYPE_FILESYSTEM)) != 0)
- verify(zfs_prop_get(*zb, ZFS_PROP_MOUNTPOINT, mountb,
+ gotb = (zfs_get_type(zb) == ZFS_TYPE_FILESYSTEM);
+ if (gotb)
+ verify(zfs_prop_get(zb, ZFS_PROP_MOUNTPOINT, mountb,
sizeof (mountb), NULL, NULL, 0, B_FALSE) == 0);
- if (gota && gotb)
- return (strcmp(mounta, mountb));
+ if (gota && gotb) {
+ while (*a != '\0' && (*a == *b)) {
+ a++;
+ b++;
+ }
+ if (*a == *b)
+ return (0);
+ if (*a == '\0')
+ return (-1);
+ if (*b == '\0')
+ return (-1);
+ if (*a == '/')
+ return (-1);
+ if (*b == '/')
+ return (-1);
+ return (*a < *b ? -1 : *a > *b);
+ }
if (gota)
return (-1);
if (gotb)
return (1);
- return (strcmp(zfs_get_name(a), zfs_get_name(b)));
+ /*
+ * If neither filesystem has a mountpoint, revert to sorting by
+ * datset name.
+ */
+ return (strcmp(zfs_get_name(za), zfs_get_name(zb)));
}
/*
+ * Reutrn true if path2 is a child of path1
+ */
+static boolean_t
+libzfs_path_contains(const char *path1, const char *path2)
+{
+ return (strstr(path2, path1) == path2 && path2[strlen(path1)] == '/');
+}
+
+
+static int
+non_descendant_idx(zfs_handle_t **handles, size_t num_handles, int idx)
+{
+ char parent[ZFS_MAXPROPLEN];
+ char child[ZFS_MAXPROPLEN];
+ int i;
+
+ verify(zfs_prop_get(handles[idx], ZFS_PROP_MOUNTPOINT, parent,
+ sizeof (parent), NULL, NULL, 0, B_FALSE) == 0);
+
+ for (i = idx + 1; i < num_handles; i++) {
+ verify(zfs_prop_get(handles[i], ZFS_PROP_MOUNTPOINT, child,
+ sizeof (child), NULL, NULL, 0, B_FALSE) == 0);
+ if (!libzfs_path_contains(parent, child))
+ break;
+ }
+ return (i);
+}
+
+typedef struct mnt_param {
+ libzfs_handle_t *mnt_hdl;
+ tpool_t *mnt_tp;
+ zfs_handle_t **mnt_zhps; /* filesystems to mount */
+ size_t mnt_num_handles;
+ int mnt_idx; /* Index of selected entry to mount */
+ zfs_iter_f mnt_func;
+ void *mnt_data;
+} mnt_param_t;
+
+/*
+ * Allocate and populate the parameter struct for mount function, and
+ * schedule mounting of the entry selected by idx.
+ */
+static void
+zfs_dispatch_mount(libzfs_handle_t *hdl, zfs_handle_t **handles,
+ size_t num_handles, int idx, zfs_iter_f func, void *data, tpool_t *tp)
+{
+ mnt_param_t *mnt_param = zfs_alloc(hdl, sizeof (mnt_param_t));
+
+ mnt_param->mnt_hdl = hdl;
+ mnt_param->mnt_tp = tp;
+ mnt_param->mnt_zhps = handles;
+ mnt_param->mnt_num_handles = num_handles;
+ mnt_param->mnt_idx = idx;
+ mnt_param->mnt_func = func;
+ mnt_param->mnt_data = data;
+
+ (void) tpool_dispatch(tp, zfs_mount_task, (void*)mnt_param);
+}
+
+/*
+ * This is the structure used to keep state of mounting or sharing operations
+ * during a call to zpool_enable_datasets().
+ */
+typedef struct mount_state {
+ /*
+ * ms_mntstatus is set to -1 if any mount fails. While multiple threads
+ * could update this variable concurrently, no synchronization is
+ * needed as it's only ever set to -1.
+ */
+ int ms_mntstatus;
+ int ms_mntflags;
+ const char *ms_mntopts;
+} mount_state_t;
+
+static int
+zfs_mount_one(zfs_handle_t *zhp, void *arg)
+{
+ mount_state_t *ms = arg;
+ int ret = 0;
+
+ if (zfs_mount(zhp, ms->ms_mntopts, ms->ms_mntflags) != 0)
+ ret = ms->ms_mntstatus = -1;
+ return (ret);
+}
+
+static int
+zfs_share_one(zfs_handle_t *zhp, void *arg)
+{
+ mount_state_t *ms = arg;
+ int ret = 0;
+
+ if (zfs_share(zhp) != 0)
+ ret = ms->ms_mntstatus = -1;
+ return (ret);
+}
+
+/*
+ * Thread pool function to mount one file system. On completion, it finds and
+ * schedules its children to be mounted. This depends on the sorting done in
+ * zfs_foreach_mountpoint(). Note that the degenerate case (chain of entries
+ * each descending from the previous) will have no parallelism since we always
+ * have to wait for the parent to finish mounting before we can schedule
+ * its children.
+ */
+static void
+zfs_mount_task(void *arg)
+{
+ mnt_param_t *mp = arg;
+ int idx = mp->mnt_idx;
+ zfs_handle_t **handles = mp->mnt_zhps;
+ size_t num_handles = mp->mnt_num_handles;
+ char mountpoint[ZFS_MAXPROPLEN];
+
+ verify(zfs_prop_get(handles[idx], ZFS_PROP_MOUNTPOINT, mountpoint,
+ sizeof (mountpoint), NULL, NULL, 0, B_FALSE) == 0);
+
+ if (mp->mnt_func(handles[idx], mp->mnt_data) != 0)
+ return;
+
+ /*
+ * We dispatch tasks to mount filesystems with mountpoints underneath
+ * this one. We do this by dispatching the next filesystem with a
+ * descendant mountpoint of the one we just mounted, then skip all of
+ * its descendants, dispatch the next descendant mountpoint, and so on.
+ * The non_descendant_idx() function skips over filesystems that are
+ * descendants of the filesystem we just dispatched.
+ */
+ for (int i = idx + 1; i < num_handles;
+ i = non_descendant_idx(handles, num_handles, i)) {
+ char child[ZFS_MAXPROPLEN];
+ verify(zfs_prop_get(handles[i], ZFS_PROP_MOUNTPOINT,
+ child, sizeof (child), NULL, NULL, 0, B_FALSE) == 0);
+
+ if (!libzfs_path_contains(mountpoint, child))
+ break; /* not a descendant, return */
+ zfs_dispatch_mount(mp->mnt_hdl, handles, num_handles, i,
+ mp->mnt_func, mp->mnt_data, mp->mnt_tp);
+ }
+ free(mp);
+}
+
+/*
+ * Issue the func callback for each ZFS handle contained in the handles
+ * array. This function is used to mount all datasets, and so this function
+ * guarantees that filesystems for parent mountpoints are called before their
+ * children. As such, before issuing any callbacks, we first sort the array
+ * of handles by mountpoint.
+ *
+ * Callbacks are issued in one of two ways:
+ *
+ * 1. Sequentially: If the parallel argument is B_FALSE or the ZFS_SERIAL_MOUNT
+ * environment variable is set, then we issue callbacks sequentially.
+ *
+ * 2. In parallel: If the parallel argument is B_TRUE and the ZFS_SERIAL_MOUNT
+ * environment variable is not set, then we use a tpool to dispatch threads
+ * to mount filesystems in parallel. This function dispatches tasks to mount
+ * the filesystems at the top-level mountpoints, and these tasks in turn
+ * are responsible for recursively mounting filesystems in their children
+ * mountpoints.
+ */
+void
+zfs_foreach_mountpoint(libzfs_handle_t *hdl, zfs_handle_t **handles,
+ size_t num_handles, zfs_iter_f func, void *data, boolean_t parallel)
+{
+ zoneid_t zoneid = getzoneid();
+
+ /*
+ * The ZFS_SERIAL_MOUNT environment variable is an undocumented
+ * variable that can be used as a convenience to do a/b comparison
+ * of serial vs. parallel mounting.
+ */
+ boolean_t serial_mount = !parallel ||
+ (getenv("ZFS_SERIAL_MOUNT") != NULL);
+
+ /*
+ * Sort the datasets by mountpoint. See mountpoint_cmp for details
+ * of how these are sorted.
+ */
+ qsort(handles, num_handles, sizeof (zfs_handle_t *), mountpoint_cmp);
+
+ if (serial_mount) {
+ for (int i = 0; i < num_handles; i++) {
+ func(handles[i], data);
+ }
+ return;
+ }
+
+ /*
+ * Issue the callback function for each dataset using a parallel
+ * algorithm that uses a thread pool to manage threads.
+ */
+ tpool_t *tp = tpool_create(1, mount_tp_nthr, 0, NULL);
+
+ /*
+ * There may be multiple "top level" mountpoints outside of the pool's
+ * root mountpoint, e.g.: /foo /bar. Dispatch a mount task for each of
+ * these.
+ */
+ for (int i = 0; i < num_handles;
+ i = non_descendant_idx(handles, num_handles, i)) {
+ /*
+ * Since the mountpoints have been sorted so that the zoned
+ * filesystems are at the end, a zoned filesystem seen from
+ * the global zone means that we're done.
+ */
+ if (zoneid == GLOBAL_ZONEID &&
+ zfs_prop_get_int(handles[i], ZFS_PROP_ZONED))
+ break;
+ zfs_dispatch_mount(hdl, handles, num_handles, i, func, data,
+ tp);
+ }
+
+ tpool_wait(tp); /* wait for all scheduled mounts to complete */
+ tpool_destroy(tp);
+}
+
+/*
* Mount and share all datasets within the given pool. This assumes that no
- * datasets within the pool are currently mounted. Because users can create
- * complicated nested hierarchies of mountpoints, we first gather all the
- * datasets and mountpoints within the pool, and sort them by mountpoint. Once
- * we have the list of all filesystems, we iterate over them in order and mount
- * and/or share each one.
+ * datasets within the pool are currently mounted.
*/
#pragma weak zpool_mount_datasets = zpool_enable_datasets
int
zpool_enable_datasets(zpool_handle_t *zhp, const char *mntopts, int flags)
{
get_all_cb_t cb = { 0 };
- libzfs_handle_t *hdl = zhp->zpool_hdl;
+ mount_state_t ms = { 0 };
zfs_handle_t *zfsp;
- int i, ret = -1;
- int *good;
+ int ret = 0;
- /*
- * Gather all non-snap datasets within the pool.
- */
- if ((zfsp = zfs_open(hdl, zhp->zpool_name, ZFS_TYPE_DATASET)) == NULL)
+ if ((zfsp = zfs_open(zhp->zpool_hdl, zhp->zpool_name,
+ ZFS_TYPE_DATASET)) == NULL)
goto out;
- libzfs_add_handle(&cb, zfsp);
- if (zfs_iter_filesystems(zfsp, mount_cb, &cb) != 0)
- goto out;
/*
- * Sort the datasets by mountpoint.
+ * Gather all non-snapshot datasets within the pool. Start by adding
+ * the root filesystem for this pool to the list, and then iterate
+ * over all child filesystems.
*/
- qsort(cb.cb_handles, cb.cb_used, sizeof (void *),
- libzfs_dataset_cmp);
+ libzfs_add_handle(&cb, zfsp);
+ if (zfs_iter_filesystems(zfsp, zfs_iter_cb, &cb) != 0)
+ goto out;
/*
- * And mount all the datasets, keeping track of which ones
- * succeeded or failed.
+ * Mount all filesystems
*/
- if ((good = zfs_alloc(zhp->zpool_hdl,
- cb.cb_used * sizeof (int))) == NULL)
- goto out;
+ ms.ms_mntopts = mntopts;
+ ms.ms_mntflags = flags;
+ zfs_foreach_mountpoint(zhp->zpool_hdl, cb.cb_handles, cb.cb_used,
+ zfs_mount_one, &ms, B_TRUE);
+ if (ms.ms_mntstatus != 0)
+ ret = ms.ms_mntstatus;
- ret = 0;
- for (i = 0; i < cb.cb_used; i++) {
- if (zfs_mount(cb.cb_handles[i], mntopts, flags) != 0)
- ret = -1;
- else
- good[i] = 1;
- }
-
/*
- * Then share all the ones that need to be shared. This needs
- * to be a separate pass in order to avoid excessive reloading
- * of the configuration. Good should never be NULL since
- * zfs_alloc is supposed to exit if memory isn't available.
+ * Share all filesystems that need to be shared. This needs to be
+ * a separate pass because libshare is not mt-safe, and so we need
+ * to share serially.
*/
- for (i = 0; i < cb.cb_used; i++) {
- if (good[i] && zfs_share(cb.cb_handles[i]) != 0)
- ret = -1;
- }
+ ms.ms_mntstatus = 0;
+ zfs_foreach_mountpoint(zhp->zpool_hdl, cb.cb_handles, cb.cb_used,
+ zfs_share_one, &ms, B_FALSE);
+ if (ms.ms_mntstatus != 0)
+ ret = ms.ms_mntstatus;
- free(good);
-
out:
- for (i = 0; i < cb.cb_used; i++)
+ for (int i = 0; i < cb.cb_used; i++)
zfs_close(cb.cb_handles[i]);
free(cb.cb_handles);
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