svn commit: r324195 - in head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs: . sys
Andriy Gapon
avg at FreeBSD.org
Mon Oct 2 11:15:33 UTC 2017
Author: avg
Date: Mon Oct 2 11:15:32 2017
New Revision: 324195
URL: https://svnweb.freebsd.org/changeset/base/324195
Log:
MFV r323795: 8604 Avoid unnecessary work search in VFS when unmounting snapshots
illumos/illumos-gate at ed992b0aac4e5b70dc1273b1d055c0d471fbb4b1
https://github.com/illumos/illumos-gate/commit/ed992b0aac4e5b70dc1273b1d055c0d471fbb4b1
https://www.illumos.org/issues/8604
Every time we want to unmount a snapshot (happens during snapshot deletion or
renaming) we unnecessarily iterate through all the mountpoints in the VFS layer
(see zfs_get_vfs).
Ideally we would just put a hold on the snapshot and access its respective VFS
resource directly.
Reviewed by: Matt Ahrens <mahrens at delphix.com>
Reviewed by: George Wilson <george.wilson at delphix.com>
Reviewed by: Andy Stormont <astormont at racktopsystems.com>
Approved by: Robert Mustacchi <rm at joyent.com>
Author: Serapheim Dimitropoulos <serapheim at delphix.com>
FreeBSD note: I added a FreeBSD specific function getzfsvfs_ref() which
is like getzfsvfs() but returns a filesystem referenced, not busied.
We want a busied filesystem in most cases, because we access its private
data and, thus, we need to prevent the filesystem from being unmounted
and its private data destroyed. But in some cases we can either get
away with just a referenced filesystem or we must not busy the
filesystem. Unmounting the filesystem is one of such cases.
MFC after: 5 weeks
X-MFC after: r324163
Modified:
head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_destroy.c
head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zfs_ioctl.h
head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c
Directory Properties:
head/sys/cddl/contrib/opensolaris/ (props changed)
Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_destroy.c
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_destroy.c Mon Oct 2 11:07:48 2017 (r324194)
+++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_destroy.c Mon Oct 2 11:15:32 2017 (r324195)
@@ -488,23 +488,29 @@ dsl_destroy_snapshots_nvl(nvlist_t *snaps, boolean_t d
if (nvlist_next_nvpair(snaps, NULL) == NULL)
return (0);
- nvlist_t *arg = fnvlist_alloc();
- nvlist_t *snaps_normalized = fnvlist_alloc();
/*
* lzc_destroy_snaps() is documented to take an nvlist whose
- * values "don't matter". We need to convert that nvlist to one
- * that we know can be converted to LUA.
+ * values "don't matter". We need to convert that nvlist to
+ * one that we know can be converted to LUA. We also don't
+ * care about any duplicate entries because the nvlist will
+ * be converted to a LUA table which should take care of this.
*/
+ nvlist_t *snaps_normalized;
+ VERIFY0(nvlist_alloc(&snaps_normalized, 0, KM_SLEEP));
for (nvpair_t *pair = nvlist_next_nvpair(snaps, NULL);
pair != NULL; pair = nvlist_next_nvpair(snaps, pair)) {
fnvlist_add_boolean_value(snaps_normalized,
nvpair_name(pair), B_TRUE);
}
+
+ nvlist_t *arg;
+ VERIFY0(nvlist_alloc(&arg, 0, KM_SLEEP));
fnvlist_add_nvlist(arg, "snaps", snaps_normalized);
fnvlist_free(snaps_normalized);
fnvlist_add_boolean_value(arg, "defer", defer);
- nvlist_t *wrapper = fnvlist_alloc();
+ nvlist_t *wrapper;
+ VERIFY0(nvlist_alloc(&wrapper, 0, KM_SLEEP));
fnvlist_add_nvlist(wrapper, ZCP_ARG_ARGLIST, arg);
fnvlist_free(arg);
@@ -538,7 +544,7 @@ dsl_destroy_snapshots_nvl(nvlist_t *snaps, boolean_t d
program,
0,
zfs_lua_max_memlimit,
- fnvlist_lookup_nvpair(wrapper, ZCP_ARG_ARGLIST), result);
+ nvlist_next_nvpair(wrapper, NULL), result);
if (error != 0) {
char *errorstr = NULL;
(void) nvlist_lookup_string(result, ZCP_RET_ERROR, &errorstr);
Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zfs_ioctl.h
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zfs_ioctl.h Mon Oct 2 11:07:48 2017 (r324194)
+++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zfs_ioctl.h Mon Oct 2 11:15:32 2017 (r324195)
@@ -21,7 +21,7 @@
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2011-2012 Pawel Jakub Dawidek. All rights reserved.
- * Copyright (c) 2012, 2016 by Delphix. All rights reserved.
+ * Copyright (c) 2012, 2017 by Delphix. All rights reserved.
* Copyright 2016 RackTop Systems.
* Copyright (c) 2014 Integros [integros.com]
*/
@@ -424,9 +424,10 @@ extern int zfs_secpolicy_snapshot_perms(const char *,
extern int zfs_secpolicy_rename_perms(const char *, const char *, cred_t *);
extern int zfs_secpolicy_destroy_perms(const char *, cred_t *);
extern int zfs_busy(void);
-extern int zfs_unmount_snap(const char *);
+extern void zfs_unmount_snap(const char *);
extern void zfs_destroy_unmount_origin(const char *);
extern int getzfsvfs_impl(struct objset *, struct zfsvfs **);
+extern int getzfsvfs(const char *, struct zfsvfs **);
/*
* ZFS minor numbers can refer to either a control device instance or
Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c Mon Oct 2 11:07:48 2017 (r324194)
+++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c Mon Oct 2 11:15:32 2017 (r324195)
@@ -1460,7 +1460,8 @@ getzfsvfs_impl(objset_t *os, zfsvfs_t **zfvp)
return (error);
}
-static int
+#ifdef illumos
+int
getzfsvfs(const char *dsname, zfsvfs_t **zfvp)
{
objset_t *os;
@@ -1472,16 +1473,44 @@ getzfsvfs(const char *dsname, zfsvfs_t **zfvp)
error = getzfsvfs_impl(os, zfvp);
dmu_objset_rele(os, FTAG);
- if (error == 0) {
- error = vfs_busy((*zfvp)->z_vfs, 0);
- vfs_rel((*zfvp)->z_vfs);
- if (error != 0) {
- *zfvp = NULL;
- error = SET_ERROR(ESRCH);
- }
+ return (error);
+}
+
+#else
+
+static int
+getzfsvfs_ref(const char *dsname, zfsvfs_t **zfvp)
+{
+ objset_t *os;
+ int error;
+
+ error = dmu_objset_hold(dsname, FTAG, &os);
+ if (error != 0)
+ return (error);
+
+ error = getzfsvfs_impl(os, zfvp);
+ dmu_objset_rele(os, FTAG);
+ return (error);
+}
+
+int
+getzfsvfs(const char *dsname, zfsvfs_t **zfvp)
+{
+ objset_t *os;
+ int error;
+
+ error = getzfsvfs_ref(dsname, zfvp);
+ if (error != 0)
+ return (error);
+ error = vfs_busy((*zfvp)->z_vfs, 0);
+ vfs_rel((*zfvp)->z_vfs);
+ if (error != 0) {
+ *zfvp = NULL;
+ error = SET_ERROR(ESRCH);
}
return (error);
}
+#endif
/*
* Find a zfsvfs_t for a mounted filesystem, or create our own, in which
@@ -3055,27 +3084,6 @@ zfs_ioc_get_fsacl(zfs_cmd_t *zc)
return (error);
}
-/*
- * Search the vfs list for a specified resource. Returns a pointer to it
- * or NULL if no suitable entry is found. The caller of this routine
- * is responsible for releasing the returned vfs pointer.
- */
-static vfs_t *
-zfs_get_vfs(const char *resource)
-{
- vfs_t *vfsp;
-
- mtx_lock(&mountlist_mtx);
- TAILQ_FOREACH(vfsp, &mountlist, mnt_list) {
- if (strcmp(refstr_value(vfsp->vfs_resource), resource) == 0) {
- vfs_ref(vfsp);
- break;
- }
- }
- mtx_unlock(&mountlist_mtx);
- return (vfsp);
-}
-
/* ARGSUSED */
static void
zfs_create_cb(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx)
@@ -3557,30 +3565,29 @@ zfs_ioc_nextboot(const char *unused, nvlist_t *innvl,
* Returns 0 if the argument is not a snapshot, or it is not currently a
* filesystem, or we were able to unmount it. Returns error code otherwise.
*/
-int
+void
zfs_unmount_snap(const char *snapname)
{
- vfs_t *vfsp;
- zfsvfs_t *zfsvfs;
-#ifdef illumos
- int err;
-#endif
+ vfs_t *vfsp = NULL;
+ zfsvfs_t *zfsvfs = NULL;
if (strchr(snapname, '@') == NULL)
- return (0);
+ return;
- vfsp = zfs_get_vfs(snapname);
- if (vfsp == NULL)
- return (0);
+ int err = getzfsvfs_ref(snapname, &zfsvfs);
+ if (err != 0) {
+ ASSERT3P(zfsvfs, ==, NULL);
+ return;
+ }
+ vfsp = zfsvfs->z_vfs;
- zfsvfs = vfsp->vfs_data;
ASSERT(!dsl_pool_config_held(dmu_objset_pool(zfsvfs->z_os)));
#ifdef illumos
err = vn_vfswlock(vfsp->vfs_vnodecovered);
VFS_RELE(vfsp);
if (err != 0)
- return (SET_ERROR(err));
+ return;
#endif
/*
@@ -3591,14 +3598,14 @@ zfs_unmount_snap(const char *snapname)
#else
(void) dounmount(vfsp, MS_FORCE, curthread);
#endif
- return (0);
}
/* ARGSUSED */
static int
zfs_unmount_snap_cb(const char *snapname, void *arg)
{
- return (zfs_unmount_snap(snapname));
+ zfs_unmount_snap(snapname);
+ return (0);
}
/*
@@ -3621,7 +3628,7 @@ zfs_destroy_unmount_origin(const char *fsname)
char originname[ZFS_MAX_DATASET_NAME_LEN];
dsl_dataset_name(ds->ds_prev, originname);
dmu_objset_rele(os, FTAG);
- (void) zfs_unmount_snap(originname);
+ zfs_unmount_snap(originname);
} else {
dmu_objset_rele(os, FTAG);
}
@@ -3662,9 +3669,7 @@ zfs_ioc_destroy_snaps(const char *poolname, nvlist_t *
(name[poollen] != '/' && name[poollen] != '@'))
return (SET_ERROR(EXDEV));
- error = zfs_unmount_snap(name);
- if (error != 0)
- return (error);
+ zfs_unmount_snap(nvpair_name(pair));
#if defined(__FreeBSD__)
zvol_remove_minors(name);
#endif
@@ -3810,11 +3815,8 @@ zfs_ioc_destroy(zfs_cmd_t *zc)
{
int err;
- if (zc->zc_objset_type == DMU_OST_ZFS) {
- err = zfs_unmount_snap(zc->zc_name);
- if (err != 0)
- return (err);
- }
+ if (zc->zc_objset_type == DMU_OST_ZFS)
+ zfs_unmount_snap(zc->zc_name);
if (strchr(zc->zc_name, '@'))
err = dsl_destroy_snapshot(zc->zc_name, zc->zc_defer_destroy);
@@ -3886,7 +3888,9 @@ recursive_unmount(const char *fsname, void *arg)
char fullname[ZFS_MAX_DATASET_NAME_LEN];
(void) snprintf(fullname, sizeof (fullname), "%s@%s", fsname, snapname);
- return (zfs_unmount_snap(fullname));
+ zfs_unmount_snap(fullname);
+
+ return (0);
}
/*
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