Assume a default thin pool named 'lxc'.

Will fallback to no thinpool if not present or if thin pool provided on the command line does not exist.

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

diff --git a/doc/lxc-create.sgml.in b/doc/lxc-create.sgml.in
index 23d7680b4e76b1802ac90ba7a35eeedf2072d3d9..b9537466883129a459e3e08c0841a1b440d6b64b 100644 (file)
--- a/doc/lxc-create.sgml.in
+++ b/doc/lxc-create.sgml.in
@@ -145,7 +145,8 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
            rather than the default, <filename>lxc</filename>.
            <replaceable>--thinpool thinpool1</replaceable> will create the
            LV as a thin-provisioned volume in the pool named
-           <filename>thinpool1</filename>.
+           <filename>thinpool1</filename> rather than the
+           default, <filename>lxc</filename>.
            <replaceable>--fstype FSTYPE</replaceable> will create an FSTYPE
            filesystem on the LV, rather than the default, which is ext4.
            <replaceable>--fssize SIZE</replaceable> will create a LV (and

diff --git a/src/lxc/bdev.c b/src/lxc/bdev.c
index 39b17116f5a4eb8d87f6654bf21faa4811461edf..671a0b6914dac9dcfd0d90c8be766413f978a43f 100644 (file)
--- a/src/lxc/bdev.c
+++ b/src/lxc/bdev.c
@@ -811,54 +811,7 @@ static int lvm_umount(struct bdev *bdev)
        return umount(bdev->dest);
 }
 
-/*
- * path must be '/dev/$vg/$lv', $vg must be an existing VG, and $lv must
- * not yet exist.  This function will attempt to create /dev/$vg/$lv of
- * size $size.
- */
-static int do_lvm_create(const char *path, unsigned long size, const char *thinpool)
-{
-       int ret, pid;
-       char sz[24], *pathdup, *vg, *lv;
-
-       if ((pid = fork()) < 0) {
-               SYSERROR("failed fork");
-               return -1;
-       }
-       if (pid > 0)
-               return wait_for_pid(pid);
-
-       process_unlock(); // we're no longer sharing
-       // lvcreate default size is in M, not bytes.
-       ret = snprintf(sz, 24, "%lu", size/1000000);
-       if (ret < 0 || ret >= 24)
-               exit(1);
-
-       pathdup = strdup(path);
-       if (!pathdup)
-               exit(1);
-       lv = strrchr(pathdup, '/');
-       if (!lv) {
-               free(pathdup);
-               exit(1);
-       }
-       *lv = '\0';
-       lv++;
-       vg = strrchr(pathdup, '/');
-       if (!vg)
-               exit(1);
-       vg++;
-       if (!thinpool) {
-           execlp("lvcreate", "lvcreate", "-L", sz, vg, "-n", lv, (char *)NULL);
-       } else {
-           execlp("lvcreate", "lvcreate", "--thinpool", thinpool, "-V", sz, vg, "-n", lv, (char *)NULL);
-       }
-       free(pathdup);
-       exit(1);
-}
-
-static int lvm_is_thin_volume(const char *path)
-{
+static int lvm_compare_lv_attr(const char *path, int pos, const char expected) {
        FILE *f;
        int ret, len, start=0;
        char *cmd, output[12];
@@ -899,12 +852,93 @@ static int lvm_is_thin_volume(const char *path)
        len = strlen(output);
        while(start < len && output[start] == ' ') start++;
 
-       if (start + 6 < len && output[start + 6] == 't')
+       if (start + pos < len && output[start + pos] == expected)
                return 1;
 
        return 0;
 }
 
+static int lvm_is_thin_volume(const char *path)
+{
+       return lvm_compare_lv_attr(path, 6, 't');
+}
+
+static int lvm_is_thin_pool(const char *path)
+{
+       return lvm_compare_lv_attr(path, 0, 't');
+}
+
+/*
+ * path must be '/dev/$vg/$lv', $vg must be an existing VG, and $lv must not
+ * yet exist.  This function will attempt to create /dev/$vg/$lv of size
+ * $size. If thinpool is specified, we'll check for it's existence and if it's
+ * a valid thin pool, and if so, we'll create the requested lv from that thin
+ * pool.
+ */
+static int do_lvm_create(const char *path, unsigned long size, const char *thinpool)
+{
+       int ret, pid, len;
+       char sz[24], *pathdup, *vg, *lv, *tp;
+
+       if ((pid = fork()) < 0) {
+               SYSERROR("failed fork");
+               return -1;
+       }
+       if (pid > 0)
+               return wait_for_pid(pid);
+
+       process_unlock(); // we're no longer sharing
+       // lvcreate default size is in M, not bytes.
+       ret = snprintf(sz, 24, "%lu", size/1000000);
+       if (ret < 0 || ret >= 24)
+               exit(1);
+
+       pathdup = strdup(path);
+       if (!pathdup)
+               exit(1);
+
+       lv = strrchr(pathdup, '/');
+       if (!lv) {
+               free(pathdup);
+               exit(1);
+       }
+       *lv = '\0';
+       lv++;
+
+       vg = strrchr(pathdup, '/');
+       if (!vg)
+               exit(1);
+       vg++;
+
+       if (thinpool) {
+               len = strlen(pathdup) + strlen(thinpool) + 2;
+               tp = alloca(len);
+
+               INFO("checking for thin pool at path: %s", tp);
+               ret = snprintf(tp, len, "%s/%s", pathdup, thinpool);
+               if (ret < 0 || ret >= len)
+                       return -1;
+
+               ret = lvm_is_thin_pool(tp);
+               INFO("got %d for thin pool at path: %s", ret, tp);
+               if (ret < 0)
+                       return ret;
+
+               if (!ret)
+                       thinpool = NULL;
+       }
+
+
+       if (!thinpool) {
+           execlp("lvcreate", "lvcreate", "-L", sz, vg, "-n", lv, (char *)NULL);
+       } else {
+           execlp("lvcreate", "lvcreate", "--thinpool", thinpool, "-V", sz, vg, "-n", lv, (char *)NULL);
+       }
+
+       free(pathdup);
+       exit(1);
+}
+
 static int lvm_snapshot(const char *orig, const char *path, unsigned long size)
 {
        int ret, pid;
@@ -1028,7 +1062,7 @@ static int lvm_clonepaths(struct bdev *orig, struct bdev *new, const char *oldna
                        return -1;
                }
        } else {
-               if (do_lvm_create(new->src, size, NULL) < 0) {
+               if (do_lvm_create(new->src, size, default_lvm_thin_pool()) < 0) {
                        ERROR("Error creating new lvm blockdev");
                        return -1;
                }
@@ -1073,6 +1107,8 @@ static int lvm_create(struct bdev *bdev, const char *dest, const char *n,
                vg = default_lvm_vg();
 
        thinpool = specs->u.lvm.thinpool;
+       if (!thinpool)
+               thinpool = default_lvm_thin_pool();
 
        /* /dev/$vg/$lv */
        if (specs->u.lvm.lv)
@@ -1091,7 +1127,6 @@ static int lvm_create(struct bdev *bdev, const char *dest, const char *n,
        if (!sz)
                sz = DEFAULT_FS_SIZE;
 
-       INFO("Error creating new lvm blockdev %s size %lu", bdev->src, sz);
        if (do_lvm_create(bdev->src, sz, thinpool) < 0) {
                ERROR("Error creating new lvm blockdev %s size %lu", bdev->src, sz);
                return -1;

diff --git a/src/lxc/lxc_create.c b/src/lxc/lxc_create.c
index 15b104dda42dbabad7c58d88dff8d70112a06f0a..91f0e6c462888260e905c5fea91e75adb90a518d 100644 (file)
--- a/src/lxc/lxc_create.c
+++ b/src/lxc/lxc_create.c
@@ -132,7 +132,7 @@ Options :\n\
   --vgname=VG        Use LVM vg called VG\n\
                      (Default: lxc))\n\
   --thinpool=TP      Use LVM thin pool called TP\n\
-                     (Default: none))\n\
+                     (Default: lxc))\n\
   --fstype=TYPE      Create fstype TYPE\n\
                      (Default: ext3))\n\
   --fssize=SIZE      Create filesystem of size SIZE\n\

diff --git a/src/lxc/utils.c b/src/lxc/utils.c
index 11f5fb7b895585a7350fab4b401a80dfd871ea0f..17ac74cb47db8218116375214c4be9c169f77890 100644 (file)
--- a/src/lxc/utils.c
+++ b/src/lxc/utils.c
@@ -237,13 +237,14 @@ static char *copy_global_config_value(char *p)
 }
 
 #define DEFAULT_VG "lxc"
+#define DEFAULT_THIN_POOL "lxc"
 #define DEFAULT_ZFSROOT "lxc"
 
 const char *lxc_global_config_value(const char *option_name)
 {
        static const char *options[][2] = {
                { "lvm_vg",          DEFAULT_VG      },
-               { "lvm_thin_pool",   NULL            },
+               { "lvm_thin_pool",   DEFAULT_THIN_POOL },
                { "zfsroot",         DEFAULT_ZFSROOT },
                { "lxcpath",         LXCPATH         },
                { "cgroup.pattern",  DEFAULT_CGROUP_PATTERN },