@@ -24,6 +24,7 @@ static inline void error(const char *fmt, ...)
/* No <linux/limits.h> so have to define it here */
#define XATTR_NAME_MAX 255
+#define PATH_MAX 4096
/*
* Macros to generate set/get funcs for the struct fields
@@ -5,8 +5,74 @@
* 2017 Marek Behun, CZ.NIC, marek.behun at nic.cz
*/
-#include "btrfs.h"
#include <malloc.h>
+#include "ctree.h"
+#include "btrfs.h"
+
+/*
+ * Resolve the path of ino inside subvolume @root into @path_ret.
+ *
+ * @path_ret must be at least PATH_MAX size.
+ */
+static int get_path_in_subvol(struct btrfs_root *root, u64 ino, char *path_ret)
+{
+ struct btrfs_path path;
+ struct btrfs_key key;
+ char *tmp;
+ u64 cur = ino;
+ int ret = 0;
+
+ tmp = malloc(PATH_MAX);
+ if (!tmp)
+ return -ENOMEM;
+ tmp[0] = '\0';
+
+ btrfs_init_path(&path);
+ while (cur != BTRFS_FIRST_FREE_OBJECTID) {
+ struct btrfs_inode_ref *iref;
+ int name_len;
+
+ btrfs_release_path(&path);
+ key.objectid = cur;
+ key.type = BTRFS_INODE_REF_KEY;
+ key.offset = (u64)-1;
+
+ ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
+ /* Impossible */
+ if (ret == 0)
+ ret = -EUCLEAN;
+ if (ret < 0)
+ goto out;
+ ret = btrfs_previous_item(root, &path, cur,
+ BTRFS_INODE_REF_KEY);
+ if (ret > 0)
+ ret = -ENOENT;
+ if (ret < 0)
+ goto out;
+
+ strncpy(tmp, path_ret, PATH_MAX);
+ iref = btrfs_item_ptr(path.nodes[0], path.slots[0],
+ struct btrfs_inode_ref);
+ name_len = btrfs_inode_ref_name_len(path.nodes[0],
+ iref);
+ if (name_len > BTRFS_NAME_LEN) {
+ ret = -ENAMETOOLONG;
+ goto out;
+ }
+ read_extent_buffer(path.nodes[0], path_ret,
+ (unsigned long)(iref + 1), name_len);
+ path_ret[name_len] = '/';
+ path_ret[name_len + 1] = '\0';
+ strncat(path_ret, tmp, PATH_MAX);
+
+ btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
+ cur = key.offset;
+ }
+out:
+ btrfs_release_path(&path);
+ free(tmp);
+ return ret;
+}
static int get_subvol_name(u64 subvolid, char *name, int max_len)
{
This patch introduces a new function, get_path_in_subvolume(), which resolve inode number into path inside a subvolume. This function will be later used for btrfs subvolume list functionality. Signed-off-by: Qu Wenruo <wqu at suse.com> --- fs/btrfs/compat.h | 1 + fs/btrfs/subvolume.c | 68 +++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 68 insertions(+), 1 deletion(-)