From 81a57679c20ac0ac9b48e313af75036132e3a5ad Mon Sep 17 00:00:00 2001 From: "M. Mohan Kumar" Date: Wed, 13 Nov 2013 22:44:43 +0530 Subject: bd: Add support to create clone, snapshot and merge of LV images. Special xattr names "clone" & "snapshot" can be used to create full and linked clone of the LV images. GFID of destination posix file (to be mapped) is passed as a value to the xattr. Destination posix file must exist before running this operation. These operations form a basis for offloading storage related operations from QEMU to GlusterFS. Syntax for full clone: xattr name: "clone" value: "gfid-of-dest-file" Syntax for linked clone: xattr name: "snapshot" value: "gfid-of-dest-file" Syntax for merging: xattr name: "merge" value: "path-to-snapshot-file" Example: setfattr -n clone -v /media/source setfattr -n snapshot -v /media/source setfattr -n merge -v "/media/sn" /media/sn Change-Id: Id9f984a709d4c2e52a64ae75bb12a8ecb01f8776 BUG: 1028672 Signed-off-by: M. Mohan Kumar Reviewed-on: http://review.gluster.org/5626 Tested-by: Gluster Build System Reviewed-by: Anand Avati --- xlators/storage/bd/src/bd-helper.c | 202 +++++++++++++++++++++++++++++++++++++ 1 file changed, 202 insertions(+) (limited to 'xlators/storage/bd/src/bd-helper.c') diff --git a/xlators/storage/bd/src/bd-helper.c b/xlators/storage/bd/src/bd-helper.c index 8781f9fdfb4..5525e346bd7 100644 --- a/xlators/storage/bd/src/bd-helper.c +++ b/xlators/storage/bd/src/bd-helper.c @@ -579,3 +579,205 @@ bd_update_amtime(struct iatt *iatt, int flag) iatt->ia_mtime_nsec = ts.tv_nsec; } } + +int +bd_snapshot_create (bd_local_t *local, bd_priv_t *priv) +{ + char *path = NULL; + bd_gfid_t dest = {0, }; + bd_gfid_t origin = {0, }; + int ret = 0; + runner_t runner = {0, }; + struct stat stat = {0, }; + + uuid_utoa_r (local->dloc->gfid, dest); + uuid_utoa_r (local->loc.gfid, origin); + + gf_asprintf (&path, "/dev/%s/%s", priv->vg, dest); + if (!path) { + gf_log (THIS->name, GF_LOG_WARNING, + "Insufficient memory"); + return ENOMEM; + } + + runinit (&runner); + runner_add_args (&runner, LVM_CREATE, NULL); + runner_add_args (&runner, "--snapshot", NULL); + runner_argprintf (&runner, "/dev/%s/%s", priv->vg, origin); + runner_add_args (&runner, "--name", NULL); + runner_argprintf (&runner, "%s", dest); + if (strcmp (local->bdatt->type, BD_THIN)) + runner_argprintf (&runner, "-L%ldB", local->size); + runner_start (&runner); + runner_end (&runner); + + if (lstat (path, &stat) < 0) + ret = EIO; + + GF_FREE (path); + return ret; +} + +int +bd_clone (bd_local_t *local, bd_priv_t *priv) +{ + int ret = ENOMEM; + int fd1 = -1; + int fd2 = -1; + int i = 0; + char *buff = NULL; + ssize_t bytes = 0; + char *spath = NULL; + char *dpath = NULL; + struct iovec *vec = NULL; + bd_gfid_t source = {0, }; + bd_gfid_t dest = {0, }; + void *bufp[IOV_NR] = {0, }; + + vec = GF_CALLOC (IOV_NR, sizeof (struct iovec), gf_common_mt_iovec); + if (!vec) + return ENOMEM; + + for (i = 0; i < IOV_NR; i++) { + bufp[i] = page_aligned_alloc (IOV_SIZE, &buff); + if (!buff) + goto out; + vec[i].iov_base = buff; + vec[i].iov_len = IOV_SIZE; + } + + uuid_utoa_r (local->loc.gfid, source); + uuid_utoa_r (local->dloc->gfid, dest); + + gf_asprintf (&spath, "/dev/%s/%s", priv->vg, source); + gf_asprintf (&dpath, "/dev/%s/%s", priv->vg, dest); + if (!spath || !dpath) + goto out; + + ret = bd_create (local->dloc->gfid, local->size, + local->bdatt->type, priv); + if (ret) + goto out; + + fd1 = open (spath, O_RDONLY | O_DIRECT); + if (fd1 < 0) { + ret = errno; + goto out; + } + fd2 = open (dpath, O_WRONLY | O_DIRECT); + if (fd2 < 0) { + ret = errno; + goto out; + } + + while (1) { + bytes = readv (fd1, vec, IOV_NR); + if (bytes < 0) { + ret = errno; + gf_log (THIS->name, GF_LOG_WARNING, "read failed: %s", + strerror (ret)); + goto out; + } + if (!bytes) + break; + bytes = writev (fd2, vec, IOV_NR); + if (bytes < 0) { + ret = errno; + gf_log (THIS->name, GF_LOG_WARNING, + "write failed: %s", strerror (ret)); + goto out; + } + } + ret = 0; + +out: + for (i = 0; i < IOV_NR; i++) + GF_FREE (bufp[i]); + GF_FREE (vec); + + if (fd1 != -1) + close (fd1); + if (fd2 != -1) + close (fd2); + + FREE (spath); + FREE (dpath); + + return ret; +} + +/* + * Merges snapshot LV to origin LV and returns status + */ +int +bd_merge (bd_priv_t *priv, uuid_t gfid) +{ + bd_gfid_t dest = {0, }; + char *path = NULL; + struct stat stat = {0, }; + runner_t runner = {0, }; + int ret = 0; + + uuid_utoa_r (gfid, dest); + gf_asprintf (&path, "/dev/%s/%s", priv->vg, dest); + + runinit (&runner); + runner_add_args (&runner, LVM_CONVERT, NULL); + runner_add_args (&runner, "--merge", NULL); + runner_argprintf (&runner, "%s", path); + runner_start (&runner); + runner_end (&runner); + + if (!lstat (path, &stat)) + ret = EIO; + + GF_FREE (path); + + return ret; +} + +int +bd_get_origin (bd_priv_t *priv, loc_t *loc, fd_t *fd, dict_t *dict) +{ + vg_t brick = NULL; + lvm_property_value_t prop = {0, }; + lv_t lv = NULL; + int ret = -1; + bd_gfid_t gfid = {0, }; + inode_t *inode = NULL; + char *origin = NULL; + + brick = lvm_vg_open (priv->handle, priv->vg, "w", 0); + if (!brick) { + gf_log (THIS->name, GF_LOG_CRITICAL, "VG %s is not found", + priv->vg); + return ENOENT; + } + + if (fd) + inode = fd->inode; + else + inode = loc->inode; + + uuid_utoa_r (inode->gfid, gfid); + lv = lvm_lv_from_name (brick, gfid); + if (!lv) { + gf_log (THIS->name, GF_LOG_CRITICAL, "LV %s not found", gfid); + ret = ENOENT; + goto out; + } + + prop = lvm_lv_get_property (lv, "origin"); + if (!prop.is_valid || !prop.value.string) { + ret = ENODATA; + goto out; + } + + origin = gf_strdup (prop.value.string); + ret = dict_set_dynstr (dict, BD_ORIGIN, origin); + +out: + lvm_vg_close (brick); + return ret; +} + -- cgit