btrfs-progs: receive: use static buffer for cur_subvol

Get rid of the allocation. The logic is changed so that a NULL
cur_subvol::path means that no subvolume/snapshot has been found so far.

Signed-off-by: David Sterba <dsterba@suse.cz>

diff --git a/cmds-receive.c b/cmds-receive.c
index 6e02efd..8dcdd29 100644 (file)
--- a/cmds-receive.c
+++ b/cmds-receive.c
@@ -64,7 +64,7 @@ struct btrfs_receive
        char *full_root_path;
        int dest_dir_chroot;
 
-       struct subvol_info *cur_subvol;
+       struct subvol_info cur_subvol;
 
        struct subvol_uuid_search sus;
 
@@ -87,21 +87,21 @@ static int finish_subvol(struct btrfs_receive *r)
        char uuid_str[BTRFS_UUID_UNPARSED_SIZE];
        u64 flags;
 
-       if (r->cur_subvol == NULL)
+       if (r->cur_subvol.path == NULL)
                return 0;
 
-       subvol_fd = openat(r->mnt_fd, r->cur_subvol->path,
+       subvol_fd = openat(r->mnt_fd, r->cur_subvol.path,
                        O_RDONLY | O_NOATIME);
        if (subvol_fd < 0) {
                ret = -errno;
                fprintf(stderr, "ERROR: open %s failed. %s\n",
-                               r->cur_subvol->path, strerror(-ret));
+                               r->cur_subvol.path, strerror(-ret));
                goto out;
        }
 
        memset(&rs_args, 0, sizeof(rs_args));
-       memcpy(rs_args.uuid, r->cur_subvol->received_uuid, BTRFS_UUID_SIZE);
-       rs_args.stransid = r->cur_subvol->stransid;
+       memcpy(rs_args.uuid, r->cur_subvol.received_uuid, BTRFS_UUID_SIZE);
+       rs_args.stransid = r->cur_subvol.stransid;
 
        if (g_verbose >= 1) {
                uuid_unparse((u8*)rs_args.uuid, uuid_str);
@@ -116,7 +116,7 @@ static int finish_subvol(struct btrfs_receive *r)
                                strerror(-ret));
                goto out;
        }
-       r->cur_subvol->rtransid = rs_args.rtransid;
+       r->cur_subvol.rtransid = rs_args.rtransid;
 
        ret = ioctl(subvol_fd, BTRFS_IOC_SUBVOL_GETFLAGS, &flags);
        if (ret < 0) {
@@ -139,10 +139,9 @@ static int finish_subvol(struct btrfs_receive *r)
        ret = 0;
 
 out:
-       if (r->cur_subvol) {
-               free(r->cur_subvol->path);
-               free(r->cur_subvol);
-               r->cur_subvol = NULL;
+       if (r->cur_subvol.path) {
+               free(r->cur_subvol.path);
+               r->cur_subvol.path = NULL;
        }
        if (subvol_fd != -1)
                close(subvol_fd);
@@ -161,25 +160,25 @@ static int process_subvol(const char *path, const u8 *uuid, u64 ctransid,
        if (ret < 0)
                goto out;
 
-       r->cur_subvol = calloc(1, sizeof(*r->cur_subvol));
+       BUG_ON(r->cur_subvol.path);
 
        if (strlen(r->dest_dir_path) == 0)
-               r->cur_subvol->path = strdup(path);
+               r->cur_subvol.path = strdup(path);
        else
-               r->cur_subvol->path = path_cat(r->dest_dir_path, path);
+               r->cur_subvol.path = path_cat(r->dest_dir_path, path);
        free(r->full_subvol_path);
        r->full_subvol_path = path_cat3(r->root_path, r->dest_dir_path, path);
 
        fprintf(stderr, "At subvol %s\n", path);
 
-       memcpy(r->cur_subvol->received_uuid, uuid, BTRFS_UUID_SIZE);
-       r->cur_subvol->stransid = ctransid;
+       memcpy(r->cur_subvol.received_uuid, uuid, BTRFS_UUID_SIZE);
+       r->cur_subvol.stransid = ctransid;
 
        if (g_verbose) {
-               uuid_unparse((u8*)r->cur_subvol->received_uuid, uuid_str);
+               uuid_unparse((u8*)r->cur_subvol.received_uuid, uuid_str);
                fprintf(stderr, "receiving subvol %s uuid=%s, stransid=%llu\n",
                                path, uuid_str,
-                               r->cur_subvol->stransid);
+                               r->cur_subvol.stransid);
        }
 
        memset(&args_v1, 0, sizeof(args_v1));
@@ -210,25 +209,25 @@ static int process_snapshot(const char *path, const u8 *uuid, u64 ctransid,
        if (ret < 0)
                goto out;
 
-       r->cur_subvol = calloc(1, sizeof(*r->cur_subvol));
+       BUG_ON(r->cur_subvol.path);
 
        if (strlen(r->dest_dir_path) == 0)
-               r->cur_subvol->path = strdup(path);
+               r->cur_subvol.path = strdup(path);
        else
-               r->cur_subvol->path = path_cat(r->dest_dir_path, path);
+               r->cur_subvol.path = path_cat(r->dest_dir_path, path);
        free(r->full_subvol_path);
        r->full_subvol_path = path_cat3(r->root_path, r->dest_dir_path, path);
 
        fprintf(stdout, "At snapshot %s\n", path);
 
-       memcpy(r->cur_subvol->received_uuid, uuid, BTRFS_UUID_SIZE);
-       r->cur_subvol->stransid = ctransid;
+       memcpy(r->cur_subvol.received_uuid, uuid, BTRFS_UUID_SIZE);
+       r->cur_subvol.stransid = ctransid;
 
        if (g_verbose) {
-               uuid_unparse((u8*)r->cur_subvol->received_uuid, uuid_str);
+               uuid_unparse((u8*)r->cur_subvol.received_uuid, uuid_str);
                fprintf(stderr, "receiving snapshot %s uuid=%s, "
                                "ctransid=%llu ", path, uuid_str,
-                               r->cur_subvol->stransid);
+                               r->cur_subvol.stransid);
                uuid_unparse(parent_uuid, uuid_str);
                fprintf(stderr, "parent_uuid=%s, parent_ctransid=%llu\n",
                                uuid_str, parent_ctransid);
@@ -633,10 +632,10 @@ static int process_clone(const char *path, u64 offset, u64 len,
        si = subvol_uuid_search(&r->sus, 0, clone_uuid, clone_ctransid, NULL,
                        subvol_search_by_received_uuid);
        if (!si) {
-               if (memcmp(clone_uuid, r->cur_subvol->received_uuid,
+               if (memcmp(clone_uuid, r->cur_subvol.received_uuid,
                                BTRFS_UUID_SIZE) == 0) {
                        /* TODO check generation of extent */
-                       subvol_path = strdup(r->cur_subvol->path);
+                       subvol_path = strdup(r->cur_subvol.path);
                } else {
                        ret = -ENOENT;
                        fprintf(stderr, "ERROR: did not find source subvol.\n");
@@ -1074,10 +1073,9 @@ out:
        r->full_subvol_path = NULL;
        r->dest_dir_path = NULL;
        free(dest_dir_full_path);
-       if (r->cur_subvol) {
-               free(r->cur_subvol->path);
-               free(r->cur_subvol);
-               r->cur_subvol = NULL;
+       if (r->cur_subvol.path) {
+               free(r->cur_subvol.path);
+               r->cur_subvol.path = NULL;
        }
        subvol_uuid_search_finit(&r->sus);
        if (r->mnt_fd != -1) {