Btrfs-progs: add parent uuid for snapshots

Signed-off-by: Anand Jain <anand.jain@oracle.com>

diff --git a/btrfs-list.c b/btrfs-list.c
index a19c3af..4e66654 100644 (file)
--- a/btrfs-list.c
+++ b/btrfs-list.c
@@ -80,6 +80,7 @@ struct root_info {
        time_t otime;
 
        u8 uuid[BTRFS_UUID_SIZE];
+       u8 puuid[BTRFS_UUID_SIZE];
 
        /* path from the subvol we live in to this root, including the
         * root's name.  This is null until we do the extra lookup ioctl.
@@ -128,6 +129,11 @@ struct {
                .need_print     = 0,
        },
        {
+               .name           = "parent_uuid",
+               .column_name    = "Parent UUID",
+               .need_print     = 0,
+       },
+       {
                .name           = "uuid",
                .column_name    = "UUID",
                .need_print     = 0,
@@ -435,7 +441,7 @@ static struct root_info *root_tree_search(struct root_lookup *root_tree,
 static int update_root(struct root_lookup *root_lookup,
                       u64 root_id, u64 ref_tree, u64 root_offset, u64 flags,
                       u64 dir_id, char *name, int name_len, u64 ogen, u64 gen,
-                      time_t ot, void *uuid)
+                      time_t ot, void *uuid, void *puuid)
 {
        struct root_info *ri;
 
@@ -472,6 +478,8 @@ static int update_root(struct root_lookup *root_lookup,
                ri->otime = ot;
        if (uuid)
                memcpy(&ri->uuid, uuid, BTRFS_UUID_SIZE);
+       if (puuid)
+               memcpy(&ri->puuid, puuid, BTRFS_UUID_SIZE);
 
        return 0;
 }
@@ -489,17 +497,18 @@ static int update_root(struct root_lookup *root_lookup,
  * gen: the current generation of the root
  * ot: the original time(create time) of the root
  * uuid: uuid of the root
+ * puuid: uuid of the root parent if any
  */
 static int add_root(struct root_lookup *root_lookup,
                    u64 root_id, u64 ref_tree, u64 root_offset, u64 flags,
                    u64 dir_id, char *name, int name_len, u64 ogen, u64 gen,
-                   time_t ot, void *uuid)
+                   time_t ot, void *uuid, void *puuid)
 {
        struct root_info *ri;
        int ret;
 
        ret = update_root(root_lookup, root_id, ref_tree, root_offset, flags,
-                         dir_id, name, name_len, ogen, gen, ot, uuid);
+                         dir_id, name, name_len, ogen, gen, ot, uuid, puuid);
        if (!ret)
                return 0;
 
@@ -537,9 +546,12 @@ static int add_root(struct root_lookup *root_lookup,
        if (ot)
                ri->otime = ot;
 
-       if (uuid) 
+       if (uuid)
                memcpy(&ri->uuid, uuid, BTRFS_UUID_SIZE);
 
+       if (puuid)
+               memcpy(&ri->puuid, puuid, BTRFS_UUID_SIZE);
+
        ret = root_tree_insert(root_lookup, ri);
        if (ret) {
                printf("failed to insert tree %llu\n", (unsigned long long)root_id);
@@ -1012,6 +1024,7 @@ static int __list_subvol_search(int fd, struct root_lookup *root_lookup)
        int i;
        time_t t;
        u8 uuid[BTRFS_UUID_SIZE];
+       u8 puuid[BTRFS_UUID_SIZE];
 
        root_lookup_init(root_lookup);
        memset(&args, 0, sizeof(args));
@@ -1064,7 +1077,7 @@ static int __list_subvol_search(int fd, struct root_lookup *root_lookup)
 
                                add_root(root_lookup, sh.objectid, sh.offset,
                                         0, 0, dir_id, name, name_len, 0, 0, 0,
-                                        NULL);
+                                        NULL, NULL);
                        } else if (sh.type == BTRFS_ROOT_ITEM_KEY) {
                                ri = (struct btrfs_root_item *)(args.buf + off);
                                gen = btrfs_root_generation(ri);
@@ -1074,15 +1087,17 @@ static int __list_subvol_search(int fd, struct root_lookup *root_lookup)
                                        t = ri->otime.sec;
                                        ogen = btrfs_root_otransid(ri);
                                        memcpy(uuid, ri->uuid, BTRFS_UUID_SIZE);
+                                       memcpy(puuid, ri->parent_uuid, BTRFS_UUID_SIZE);
                                } else {
                                        t = 0;
                                        ogen = 0;
                                        memset(uuid, 0, BTRFS_UUID_SIZE);
+                                       memset(puuid, 0, BTRFS_UUID_SIZE);
                                }
 
                                add_root(root_lookup, sh.objectid, 0,
                                         sh.offset, flags, 0, NULL, 0, ogen,
-                                        gen, t, uuid);
+                                        gen, t, uuid, puuid);
                        }
 
                        off += sh.len;
@@ -1359,6 +1374,13 @@ static void print_subvolume_column(struct root_info *subv,
                        uuid_unparse(subv->uuid, uuidparse);
                printf("%s", uuidparse);
                break;
+       case BTRFS_LIST_PUUID:
+               if (uuid_is_null(subv->puuid))
+                       strcpy(uuidparse, "-");
+               else
+                       uuid_unparse(subv->puuid, uuidparse);
+               printf("%s", uuidparse);
+               break;
        case BTRFS_LIST_PATH:
                BUG_ON(!subv->full_path);
                printf("%s", subv->full_path);

diff --git a/btrfs-list.h b/btrfs-list.h
index e5f19b2..dc18ee4 100644 (file)
--- a/btrfs-list.h
+++ b/btrfs-list.h
@@ -53,6 +53,7 @@ enum btrfs_list_column_enum {
        BTRFS_LIST_PARENT,
        BTRFS_LIST_TOP_LEVEL,
        BTRFS_LIST_OTIME,
+       BTRFS_LIST_PUUID,
        BTRFS_LIST_UUID,
        BTRFS_LIST_PATH,
        BTRFS_LIST_ALL,

diff --git a/cmds-subvolume.c b/cmds-subvolume.c
index c113757..d46064a 100644 (file)
--- a/cmds-subvolume.c
+++ b/cmds-subvolume.c
@@ -283,6 +283,7 @@ static const char * const cmd_subvol_list_usage[] = {
        "             to the given <path>",
        "-o           print only subvolumes bellow specified path",
        "-u           print the uuid of subvolumes (and snapshots)",
+       "-q           print the parent uuid of the snapshots",
        "-t           print the result as a table",
        "-s           list snapshots only in the filesystem",
        "-r           list readonly subvolumes (including snapshots)",
@@ -323,7 +324,7 @@ static int cmd_subvol_list(int argc, char **argv)
        optind = 1;
        while(1) {
                c = getopt_long(argc, argv,
-                                   "aopsurg:c:t", long_options, NULL);
+                                   "aopqsurg:c:t", long_options, NULL);
                if (c < 0)
                        break;
 
@@ -350,6 +351,9 @@ static int cmd_subvol_list(int argc, char **argv)
                case 'u':
                        btrfs_list_setup_print_column(BTRFS_LIST_UUID);
                        break;
+               case 'q':
+                       btrfs_list_setup_print_column(BTRFS_LIST_PUUID);
+                       break;
                case 'r':
                        flags |= BTRFS_ROOT_SUBVOL_RDONLY;
                        break;