btrfs-progs: btrfs_list_get_path_rootid error handling

btrfs_list_get_path_rootid() tries to return a negative
number on error, but it's a u64 function.  Callers which test
for a return < 0 will never see an error.

Change the function to fill in the rootid via a pointer,
and then return a simple int as error.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>

diff --git a/btrfs-list.c b/btrfs-list.c
index ab9179f97b52450bcf1ca9e6be8a4fe5e9f766af..851c059ea1d5b720176cdcf521ccd3d2b96193f9 100644 (file)
--- a/btrfs-list.c
+++ b/btrfs-list.c
@@ -1500,8 +1500,13 @@ int btrfs_list_subvols_print(int fd, struct btrfs_list_filter_set *filter_set,
 {
        struct root_lookup root_lookup;
        struct root_lookup root_sort;
-       int ret;
-       u64 top_id = (full_path ? 0 : btrfs_list_get_path_rootid(fd));
+       int ret = 0;
+       u64 top_id = 0;
+
+       if (full_path)
+               ret = btrfs_list_get_path_rootid(fd, &top_id);
+       if (ret)
+               return ret;
 
        ret = btrfs_list_subvols(fd, &root_lookup);
        if (ret)
@@ -1524,13 +1529,18 @@ char *strdup_or_null(const char *s)
 
 int btrfs_get_subvol(int fd, struct root_info *the_ri)
 {
-       int ret = 1, rr;
+       int ret, rr;
        struct root_lookup rl;
        struct rb_node *rbn;
        struct root_info *ri;
-       u64 root_id = btrfs_list_get_path_rootid(fd);
+       u64 root_id;
+
+       ret = btrfs_list_get_path_rootid(fd, &root_id);
+       if (ret)
+               return ret;
 
-       if (btrfs_list_subvols(fd, &rl))
+       ret = btrfs_list_subvols(fd, &rl);
+       if (ret)
                return ret;
 
        rbn = rb_first(&rl.root);
@@ -1741,7 +1751,11 @@ char *btrfs_list_path_for_root(int fd, u64 root)
        struct rb_node *n;
        char *ret_path = NULL;
        int ret;
-       u64 top_id = btrfs_list_get_path_rootid(fd);
+       u64 top_id;
+
+       ret = btrfs_list_get_path_rootid(fd, &top_id);
+       if (ret)
+               return ERR_PTR(ret);
 
        ret = __list_subvol_search(fd, &root_lookup);
        if (ret < 0)
@@ -1868,7 +1882,7 @@ int btrfs_list_parse_filter_string(char *optarg,
        return 0;
 }
 
-u64 btrfs_list_get_path_rootid(int fd)
+int btrfs_list_get_path_rootid(int fd, u64 *treeid)
 {
        int  ret;
        struct btrfs_ioctl_ino_lookup_args args;
@@ -1883,5 +1897,6 @@ u64 btrfs_list_get_path_rootid(int fd)
                        strerror(errno));
                return ret;
        }
-       return args.treeid;
+       *treeid = args.treeid;
+       return 0;
 }

diff --git a/btrfs-list.h b/btrfs-list.h
index 5d874549e82525bcd2377cfb0a22c16afd575ed5..2894451dd89d13c0ec68015a3dce9df8f28a1987 100644 (file)
--- a/btrfs-list.h
+++ b/btrfs-list.h
@@ -156,5 +156,5 @@ int btrfs_list_subvols_print(int fd, struct btrfs_list_filter_set *filter_set,
 int btrfs_list_find_updated_files(int fd, u64 root_id, u64 oldest_gen);
 int btrfs_list_get_default_subvolume(int fd, u64 *default_id);
 char *btrfs_list_path_for_root(int fd, u64 root);
-u64 btrfs_list_get_path_rootid(int fd);
+int btrfs_list_get_path_rootid(int fd, u64 *treeid);
 int btrfs_get_subvol(int fd, struct root_info *the_ri);

diff --git a/cmds-subvolume.c b/cmds-subvolume.c
index ea128fce6cef6f149c3f8e438d7f93978d3e8717..f9258fcba7fe172c4c99a43b1395dc4f035c61d3 100644 (file)
--- a/cmds-subvolume.c
+++ b/cmds-subvolume.c
@@ -433,7 +433,11 @@ static int cmd_subvol_list(int argc, char **argv)
                goto out;
        }
 
-       top_id = btrfs_list_get_path_rootid(fd);
+       ret = btrfs_list_get_path_rootid(fd, &top_id);
+       if (ret) {
+               fprintf(stderr, "ERROR: can't get rootid for '%s'\n", subvol);
+               goto out;
+       }
 
        if (is_list_all)
                btrfs_list_setup_filter(&filter_set,
@@ -821,8 +825,8 @@ static int cmd_subvol_show(int argc, char **argv)
                goto out;
        }
 
-       sv_id = btrfs_list_get_path_rootid(fd);
-       if (sv_id < 0) {
+       ret = btrfs_list_get_path_rootid(fd, &sv_id);
+       if (ret) {
                fprintf(stderr, "ERROR: can't get rootid for '%s'\n",
                        fullpath);
                goto out;
@@ -834,8 +838,8 @@ static int cmd_subvol_show(int argc, char **argv)
                goto out;
        }
 
-       mntid = btrfs_list_get_path_rootid(mntfd);
-       if (mntid < 0) {
+       ret = btrfs_list_get_path_rootid(mntfd, &mntid);
+       if (ret) {
                fprintf(stderr, "ERROR: can't get rootid for '%s'\n", mnt);
                goto out;
        }