btrfs-progs: subvol: fix subvol del --commit-after

Fix 'subvolume delete --commit-after' to work properly:
- SYNC ioctl will be issued even when last delete fails
- SYNC ioctl will be issued on each file system only once in the end

To achieve this, get_fsid() and add_seen_fsid() are called after each
delete to keep only one fd for each fs.

In the end, seen_fsid_hash will be traversed and SYNC is issued on each
fs.

Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/cmds-subvolume.c b/cmds-subvolume.c
index 8b24de3..69c5038 100644 (file)
--- a/cmds-subvolume.c
+++ b/cmds-subvolume.c
@@ -263,6 +263,9 @@ static int cmd_subvol_delete(int argc, char **argv)
        DIR     *dirstream = NULL;
        int verbose = 0;
        int commit_mode = 0;
+       u8 fsid[BTRFS_FSID_SIZE];
+       char uuidbuf[BTRFS_UUID_UNPARSED_SIZE];
+       struct seen_fsid *seen_fsid_hash[SEEN_FSID_HASH_SIZE] = { NULL, };
        enum { COMMIT_AFTER = 1, COMMIT_EACH = 2 };
 
        while (1) {
@@ -358,31 +361,74 @@ again:
                                path, strerror(errno));
                        ret = 1;
                }
+       } else if (commit_mode == COMMIT_AFTER) {
+               res = get_fsid(dname, fsid, 0);
+               if (res < 0) {
+                       error("unable to get fsid for '%s': %s",
+                               path, strerror(-res));
+                       error(
+                       "delete suceeded but commit may not be done in the end");
+                       ret = 1;
+                       goto out;
+               }
+
+               if (add_seen_fsid(fsid, seen_fsid_hash, fd, dirstream) == 0) {
+                       if (verbose > 0) {
+                               uuid_unparse(fsid, uuidbuf);
+                               printf("  new fs is found for '%s', fsid: %s\n",
+                                               path, uuidbuf);
+                       }
+                       /*
+                        * This is the first time a subvolume on this
+                        * filesystem is deleted, keep fd in order to issue
+                        * SYNC ioctl in the end
+                        */
+                       goto keep_fd;
+               }
        }
 
 out:
+       close_file_or_dir(fd, dirstream);
+keep_fd:
+       fd = -1;
+       dirstream = NULL;
        free(dupdname);
        free(dupvname);
        dupdname = NULL;
        dupvname = NULL;
        cnt++;
-       if (cnt < argc) {
-               close_file_or_dir(fd, dirstream);
-               /* avoid double free */
-               fd = -1;
-               dirstream = NULL;
+       if (cnt < argc)
                goto again;
-       }
 
-       if (commit_mode == COMMIT_AFTER && fd != -1) {
-               res = wait_for_commit(fd);
-               if (res < 0) {
-                       error("unable to do final sync after deletion: %s",
-                               strerror(errno));
-                       ret = 1;
+       if (commit_mode == COMMIT_AFTER) {
+               int slot;
+
+               /*
+                * Traverse seen_fsid_hash and issue SYNC ioctl on each
+                * filesystem
+                */
+               for (slot = 0; slot < SEEN_FSID_HASH_SIZE; slot++) {
+                       struct seen_fsid *seen = seen_fsid_hash[slot];
+
+                       while (seen) {
+                               res = wait_for_commit(seen->fd);
+                               if (res < 0) {
+                                       uuid_unparse(seen->fsid, uuidbuf);
+                                       error(
+                       "unable to do final sync after deletion: %s, fsid: %s",
+                                               strerror(errno), uuidbuf);
+                                       ret = 1;
+                               } else if (verbose > 0) {
+                                       uuid_unparse(seen->fsid, uuidbuf);
+                                       printf("final sync is done for fsid: %s\n",
+                                               uuidbuf);
+                               }
+                               seen = seen->next;
+                       }
                }
+               /* fd will also be closed in free_seen_fsid */
+               free_seen_fsid(seen_fsid_hash);
        }
-       close_file_or_dir(fd, dirstream);
 
        return ret;
 }