create: support [storage <filename>] option

$ gluster-block help
gluster-block (0.3)
usage:
  gluster-block <command> <volname[/blockname]> [<args>] [--json*]

commands:
  create  <volname/blockname> [ha <count>]
                              [auth <enable|disable>]
                              [prealloc <full|no>]
                              [storage <filename>]
                              <host1[,host2,...]> <size>
        create block device [defaults: ha 1, auth disable, prealloc no, size in bytes]
[...]
supported JSON formats:
  --json|--json-plain|--json-spaced|--json-pretty

Fixes: #18
Change-Id: I5d9b4abb58596bd2297cffb294c6d31f752d53e9
Signed-off-by: Prasanna Kumar Kalever <prasanna.kalever@redhat.com>

1 files changed, 55 insertions, 2 deletions

diff --git a/rpc/glfs-operations.c b/rpc/glfs-operations.c
index 838d3c7..341a6e2 100644
--- a/rpc/glfs-operations.c
+++ b/rpc/glfs-operations.c
@@ -91,6 +91,7 @@ glusterBlockCreateEntry(struct glfs *glfs, blockCreateCli *blk, char *gbid,
                         int *errCode, char **errMsg)
 {
   struct glfs_fd *tgfd;
+  struct stat st;
   char *tmp;
   int ret;
 
@@ -112,6 +113,56 @@ glusterBlockCreateEntry(struct glfs *glfs, blockCreateCli *blk, char *gbid,
     goto out;
   }
 
+  if (strlen(blk->storage)) {
+    ret = glfs_stat(glfs, blk->storage, &st);
+    if (ret) {
+      *errCode = errno;
+      if (*errCode == ENOENT) {
+        LOG("mgmt", GB_LOG_ERROR,
+            "storage file '/block-store/%s' doesn't exist in volume %s",
+            blk->storage, blk->volume);
+        GB_ASPRINTF(errMsg,
+                    "storage file '/block-store/%s' doesn't exist in volume %s\n",
+                    blk->storage, blk->volume);
+      } else {
+        LOG("mgmt", GB_LOG_ERROR,
+            "glfs_stat failed on /block-store/%s in volume %s [%s]",
+            blk->storage, blk->volume, strerror(*errCode));
+        GB_ASPRINTF(errMsg,
+                    "glfs_stat failed on /block-store/%s in volume %s [%s]",
+                    blk->storage, blk->volume, strerror(*errCode));
+      }
+      goto out;
+    }
+    blk->size = st.st_size;
+
+    if (st.st_nlink == 1) {
+      ret = glfs_link(glfs, blk->storage, gbid);
+      if (ret) {
+        *errCode=errno;
+        LOG("mgmt", GB_LOG_ERROR,
+            "glfs_link(%s, %s) on volume %s for block %s failed [%s]",
+            blk->storage, gbid, blk->volume, blk->block_name, strerror(errno));
+        GB_ASPRINTF(errMsg,
+                    "glfs_link(%s, %s) on volume %s for block %s failed [%s]",
+                    blk->storage, gbid, strerror(errno));
+        goto out;
+      }
+    } else {
+      *errCode = EBUSY;
+      LOG("mgmt", GB_LOG_ERROR,
+          "storage file /block-store/%s is already in use in volume %s [%s]",
+          blk->storage, blk->volume, strerror(*errCode));
+      GB_ASPRINTF(errMsg,
+                  "storage file /block-store/%s is already in use in volume %s [%s]\n"
+                  "hint: delete the hardlink file, make sure file is not in use\n",
+                  blk->storage, blk->volume, strerror(*errCode));
+      ret = -1;
+      goto out;
+    }
+    return 0;
+  }
+
   tgfd = glfs_creat(glfs, gbid,
                     O_WRONLY | O_CREAT | O_EXCL | O_SYNC,
                     S_IRUSR | S_IWUSR);
@@ -163,8 +214,10 @@ unlink:
 
  out:
   if (ret) {
-    GB_ASPRINTF (errMsg, "Not able to create storage for %s/%s [%s]",
-                 blk->volume, blk->block_name, strerror(*errCode));
+    if (!errMsg) {
+      GB_ASPRINTF (errMsg, "Not able to create storage for %s/%s [%s]",
+                   blk->volume, blk->block_name, strerror(*errCode));
+    }
 
     GB_ASPRINTF(&tmp, "%s/%s", GB_METADIR, blk->block_name);