From 26b42f3f9d03f85cc7966dc2fe4dfe9216601b0e Mon Sep 17 00:00:00 2001 From: Richard Yao Date: Mon, 1 Jul 2013 10:57:04 -0400 Subject: [PATCH] Implement -t option to zpool import for temporary pool names Originally, users had to handle spa namespace collisions by either exporting the already imported pool or by specifying a new name for the pool with a conflicting name. In the case of root pools from virtual guests, neither approach to collision resolution is reasonable. This is addressed by extending the new name syntax with a -t option to specify that the new name is temporary. When specified, this sets an internal flag that is passed into the kernel to tell it that all label updates should refer to the name used in the original label. Consequently, the original pool name will be retained on export. Signed-off-by: Richard Yao Signed-off-by: Brian Behlendorf Closes #2189 --- cmd/zpool/zpool_main.c | 6 +++++- include/sys/fs/zfs.h | 1 + man/man8/zpool.8 | 15 +++++++++++++-- module/zfs/spa_config.c | 28 ++++++++++++++++++++++++++-- 4 files changed, 45 insertions(+), 5 deletions(-) diff --git a/cmd/zpool/zpool_main.c b/cmd/zpool/zpool_main.c index 1c606e077e..d095b15a58 100644 --- a/cmd/zpool/zpool_main.c +++ b/cmd/zpool/zpool_main.c @@ -2013,7 +2013,7 @@ zpool_do_import(int argc, char **argv) char *endptr; /* check options */ - while ((c = getopt(argc, argv, ":aCc:d:DEfFmnNo:R:T:VX")) != -1) { + while ((c = getopt(argc, argv, ":aCc:d:DEfFmnNo:R:tT:VX")) != -1) { switch (c) { case 'a': do_all = B_TRUE; @@ -2075,6 +2075,10 @@ zpool_do_import(int argc, char **argv) ZPOOL_PROP_CACHEFILE), "none", &props, B_TRUE)) goto error; break; + case 't': + flags |= ZFS_IMPORT_TEMP_NAME; + break; + case 'T': errno = 0; txg = strtoull(optarg, &endptr, 10); diff --git a/include/sys/fs/zfs.h b/include/sys/fs/zfs.h index df5692d14b..882e9e84ab 100644 --- a/include/sys/fs/zfs.h +++ b/include/sys/fs/zfs.h @@ -936,6 +936,7 @@ typedef enum { #define ZFS_IMPORT_ANY_HOST 0x2 #define ZFS_IMPORT_MISSING_LOG 0x4 #define ZFS_IMPORT_ONLY 0x8 +#define ZFS_IMPORT_TEMP_NAME 0x10 /* * Sysevent payload members. ZFS will generate the following sysevents with the diff --git a/man/man8/zpool.8 b/man/man8/zpool.8 index 63037760a0..2cfa8558cd 100644 --- a/man/man8/zpool.8 +++ b/man/man8/zpool.8 @@ -84,7 +84,7 @@ zpool \- configures ZFS storage pools .LP .nf \fBzpool import\fR [\fB-o \fImntopts\fR\fR] [\fB-o\fR \fIproperty=value\fR] ... [\fB-d\fR \fIdir\fR | \fB-c\fR \fIcachefile\fR] - [\fB-D\fR] [\fB-f\fR] [\fB-m\fR] [\fB-R\fR \fIroot\fR] [\fB-F\fR [\fB-n\fR]] \fIpool\fR |\fIid\fR [\fInewpool\fR] + [\fB-D\fR] [\fB-f\fR] [\fB-m\fR] [\fB-R\fR \fIroot\fR] [\fB-F\fR [\fB-n\fR]] [\fB-t\fR]] \fIpool\fR |\fIid\fR [\fInewpool\fR] .fi .LP @@ -1300,7 +1300,7 @@ Used with the \fB-F\fR recovery option. Determines whether a non-importable pool .ne 2 .mk .na -\fB\fBzpool import\fR [\fB-o\fR \fImntopts\fR] [ \fB-o\fR \fIproperty\fR=\fIvalue\fR] ... [\fB-d\fR \fIdir\fR | \fB-c\fR \fIcachefile\fR] [\fB-D\fR] [\fB-f\fR] [\fB-m\fR] [\fB-R\fR \fIroot\fR] [\fB-F\fR [\fB-n\fR]] \fIpool\fR | \fIid\fR [\fInewpool\fR]\fR +\fB\fBzpool import\fR [\fB-o\fR \fImntopts\fR] [ \fB-o\fR \fIproperty\fR=\fIvalue\fR] ... [\fB-d\fR \fIdir\fR | \fB-c\fR \fIcachefile\fR] [\fB-D\fR] [\fB-f\fR] [\fB-m\fR] [\fB-R\fR \fIroot\fR] [\fB-F\fR [\fB-n\fR]] [\fB-t\fR]] \fIpool\fR | \fIid\fR [\fInewpool\fR]\fR .ad .sp .6 .RS 4n @@ -1406,6 +1406,17 @@ Sets the "\fBcachefile\fR" property to "\fBnone\fR" and the "\fIaltroot\fR" prop Used with the \fB-F\fR recovery option. Determines whether a non-importable pool can be made importable again, but does not actually perform the pool recovery. For more details about pool recovery mode, see the \fB-F\fR option, above. .RE +.sp +.ne 2 +.mk +.na +\fB\fB-t\fR\fR +.ad +.sp .6 +.RS 4n +Used with "\fBnewpool\fR". Specifies that "\fBnewpool\fR" is temporary. Temporary pool names last until export. Ensures that the original pool name will be used in all label updates and therefore is retained upon export. +.RE + .sp .ne 2 .mk diff --git a/module/zfs/spa_config.c b/module/zfs/spa_config.c index 5b95a8e811..c8fe79ed52 100644 --- a/module/zfs/spa_config.c +++ b/module/zfs/spa_config.c @@ -208,6 +208,7 @@ spa_config_sync(spa_t *target, boolean_t removing, boolean_t postsysevent) { spa_config_dirent_t *dp, *tdp; nvlist_t *nvl; + char *pool_name; ASSERT(MUTEX_HELD(&spa_namespace_lock)); @@ -254,7 +255,13 @@ spa_config_sync(spa_t *target, boolean_t removing, boolean_t postsysevent) VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME, KM_PUSHPAGE) == 0); - VERIFY(nvlist_add_nvlist(nvl, spa->spa_name, + if (spa->spa_import_flags & ZFS_IMPORT_TEMP_NAME) { + VERIFY0(nvlist_lookup_string(spa->spa_config, + ZPOOL_CONFIG_POOL_NAME, &pool_name)); + } else + pool_name = spa_name(spa); + + VERIFY(nvlist_add_nvlist(nvl, pool_name, spa->spa_config) == 0); mutex_exit(&spa->spa_props_lock); } @@ -337,6 +344,7 @@ spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats) unsigned long hostid = 0; boolean_t locked = B_FALSE; uint64_t split_guid; + char *pool_name; if (vd == NULL) { vd = rvd; @@ -353,12 +361,28 @@ spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats) if (txg == -1ULL) txg = spa->spa_config_txg; + /* + * Originally, users had to handle spa namespace collisions by either + * exporting the already imported pool or by specifying a new name for + * the pool with a conflicting name. In the case of root pools from + * virtual guests, neither approach to collision resolution is + * reasonable. This is addressed by extending the new name syntax with + * an option to specify that the new name is temporary. When specified, + * ZFS_IMPORT_TEMP_NAME will be set in spa->spa_import_flags to tell us + * to use the previous name, which we do below. + */ + if (spa->spa_import_flags & ZFS_IMPORT_TEMP_NAME) { + VERIFY0(nvlist_lookup_string(spa->spa_config, + ZPOOL_CONFIG_POOL_NAME, &pool_name)); + } else + pool_name = spa_name(spa); + VERIFY(nvlist_alloc(&config, NV_UNIQUE_NAME, KM_PUSHPAGE) == 0); VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION, spa_version(spa)) == 0); VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, - spa_name(spa)) == 0); + pool_name) == 0); VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE, spa_state(spa)) == 0); VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,