#include <config.h>
#include <malloc.h>
#include <u-boot/uuid.h>
+#include <linux/kernel.h>
#include <linux/time.h>
+#include <fs.h>
#include "btrfs.h"
#include "crypto/hash.h"
#include "disk-io.h"
return 0;
}
+/*
+ * The fs layer closes and re-probes btrfs between readdir() calls (see
+ * fs_readdir() in fs/fs.c), freeing and reallocating fs_info, so root cannot
+ * be stored directly. The subvolume id and inode number are stable though, so
+ * re-resolve the root from the current fs_info by subvolume id, which avoids
+ * a full path walk and is much faster.
+ */
+struct btrfs_dir_stream {
+ struct fs_dir_stream parent;
+ struct fs_dirent dirent;
+ u64 subvolid;
+ u64 ino;
+ u64 offset;
+};
+
+int btrfs_opendir(const char *dirname, struct fs_dir_stream **dirsp)
+{
+ struct btrfs_fs_info *fs_info = current_fs_info;
+ struct btrfs_dir_stream *dirs;
+ struct btrfs_root *root;
+ u64 ino;
+ u8 type;
+ int ret;
+
+ *dirsp = NULL;
+ ASSERT(fs_info);
+
+ ret = btrfs_lookup_path(fs_info->fs_root, BTRFS_FIRST_FREE_OBJECTID,
+ dirname, &root, &ino, &type, 40);
+ if (ret < 0)
+ return ret;
+ if (type != BTRFS_FT_DIR)
+ return -ENOTDIR;
+
+ dirs = calloc(1, sizeof(*dirs));
+ if (!dirs)
+ return -ENOMEM;
+ dirs->subvolid = root->root_key.objectid;
+ dirs->ino = ino;
+
+ *dirsp = &dirs->parent;
+ return 0;
+}
+
+static unsigned int btrfs_dirent_type_to_fs_type(u8 dirent_type)
+{
+ switch (dirent_type) {
+ case BTRFS_FT_DIR:
+ return FS_DT_DIR;
+ case BTRFS_FT_SYMLINK:
+ return FS_DT_LNK;
+ default:
+ return FS_DT_REG;
+ }
+}
+
+int btrfs_readdir(struct fs_dir_stream *fs_dirs, struct fs_dirent **dentp)
+{
+ struct btrfs_dir_stream *dirs = container_of(fs_dirs, struct btrfs_dir_stream, parent);
+ struct btrfs_fs_info *fs_info = current_fs_info;
+ struct fs_dirent *dent = &dirs->dirent;
+ struct btrfs_root *root;
+ struct btrfs_key key;
+ u8 type;
+ int ret;
+
+ *dentp = NULL;
+ ASSERT(fs_info);
+
+ key.objectid = dirs->subvolid;
+ key.type = BTRFS_ROOT_ITEM_KEY;
+ key.offset = (u64)-1;
+ root = btrfs_read_fs_root(fs_info, &key);
+ if (IS_ERR(root))
+ return PTR_ERR(root);
+
+ memset(dent, 0, sizeof(*dent));
+ ret = btrfs_next_dir_entry(root, dirs->ino, &dirs->offset, dent->name,
+ sizeof(dent->name), &type);
+ if (ret < 0)
+ return ret;
+ if (ret > 0)
+ return -ENOENT;
+
+ dent->type = btrfs_dirent_type_to_fs_type(type);
+ *dentp = dent;
+ return 0;
+}
+
+void btrfs_closedir(struct fs_dir_stream *fs_dirs)
+{
+ struct btrfs_dir_stream *dirs = container_of(fs_dirs, struct btrfs_dir_stream, parent);
+
+ free(dirs);
+}
+
int btrfs_exists(const char *file)
{
struct btrfs_fs_info *fs_info = current_fs_info;
struct btrfs_dir_item *di);
int btrfs_iter_dir(struct btrfs_root *root, u64 ino,
btrfs_iter_dir_callback_t callback);
+int btrfs_next_dir_entry(struct btrfs_root *root, u64 ino, u64 *offset,
+ char *namebuf, int namebuf_len, u8 *ftype);
/* inode.c */
int btrfs_lookup_path(struct btrfs_root *root, u64 ino, const char *filename,
struct btrfs_root **root_ret, u64 *ino_ret,
btrfs_release_path(&path);
return ret;
}
+
+/*
+ * btrfs_next_dir_entry() - read one directory entry at or after a cursor
+ *
+ * Streaming counterpart to btrfs_iter_dir() for the fs-layer readdir, which
+ * is re-entered once per entry: returns the first real entry whose
+ * BTRFS_DIR_INDEX_KEY offset is >= *offset and advances *offset past it.
+ *
+ * @root, @ino: directory to read
+ * @offset: in/out cursor; DIR_INDEX offset to resume from
+ * @namebuf: caller buffer that receives the NUL-terminated name
+ * @namebuf_len: size of @namebuf in bytes
+ * @ftype: receives the BTRFS_FT_* type of the entry
+ *
+ * Return: 0 if an entry was returned, 1 when the directory is exhausted,
+ * -ve on error.
+ */
+int btrfs_next_dir_entry(struct btrfs_root *root, u64 ino, u64 *offset,
+ char *namebuf, int namebuf_len, u8 *ftype)
+{
+ struct btrfs_path path;
+ struct btrfs_key key;
+ struct btrfs_dir_item *di;
+ int name_len;
+ int ret;
+
+ btrfs_init_path(&path);
+ key.objectid = ino;
+ key.type = BTRFS_DIR_INDEX_KEY;
+ key.offset = *offset;
+
+ ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
+ if (ret < 0)
+ goto out;
+
+ if (path.slots[0] >= btrfs_header_nritems(path.nodes[0])) {
+ ret = btrfs_next_leaf(root, &path);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) { /* end of tree */
+ ret = 1;
+ goto out;
+ }
+ }
+
+ btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
+ if (key.objectid != ino || key.type != BTRFS_DIR_INDEX_KEY) {
+ ret = 1; /* no more entries for this dir */
+ goto out;
+ }
+
+ di = btrfs_item_ptr(path.nodes[0], path.slots[0],
+ struct btrfs_dir_item);
+ if (verify_dir_item(root, path.nodes[0], di)) {
+ ret = -EUCLEAN;
+ goto out;
+ }
+
+ *offset = key.offset + 1;
+
+ name_len = btrfs_dir_name_len(path.nodes[0], di);
+ if (name_len > namebuf_len - 1)
+ name_len = namebuf_len - 1;
+ read_extent_buffer(path.nodes[0], namebuf,
+ (unsigned long)(di + 1), name_len);
+ namebuf[name_len] = '\0';
+ *ftype = btrfs_dir_type(path.nodes[0], di);
+ ret = 0;
+
+out:
+ btrfs_release_path(&path);
+ return ret;
+}
.read = btrfs_read,
.write = fs_write_unsupported,
.uuid = btrfs_uuid,
- .opendir = fs_opendir_unsupported,
+ .opendir = btrfs_opendir,
+ .readdir = btrfs_readdir,
+ .closedir = btrfs_closedir,
.unlink = fs_unlink_unsupported,
.mkdir = fs_mkdir_unsupported,
.ln = fs_ln_unsupported,
struct blk_desc;
struct disk_partition;
+struct fs_dir_stream;
+struct fs_dirent;
int btrfs_probe(struct blk_desc *fs_dev_desc,
struct disk_partition *fs_partition);
void btrfs_close(void);
int btrfs_uuid(char *);
void btrfs_list_subvols(void);
+int btrfs_opendir(const char *filename, struct fs_dir_stream **dirsp);
+int btrfs_readdir(struct fs_dir_stream *dirs, struct fs_dirent **dentp);
+void btrfs_closedir(struct fs_dir_stream *dirs);
#endif /* __U_BOOT_BTRFS_H__ */
projects / thirdparty / u-boot.git / commitdiff
