在 2026/6/26 02:54, Alexey Charkov 写道:
Add support for generic directory iteration with opendir(), readdir() and
closedir() in the btrfs filesystem driver, following the ext4fs
implementation for opendir()/closedir() and the btrfs_iter_dir() function
for readdir().
Signed-off-by: Alexey Charkov <[email protected]>
---
fs/btrfs/btrfs.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/btrfs/ctree.h | 2 ++
fs/btrfs/dir-item.c | 91 ++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/fs.c | 4 ++-
include/btrfs.h | 5 +++
5 files changed, 193 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/btrfs.c b/fs/btrfs/btrfs.c
index f3087f690fa4..c647c8dedf4e 100644
--- a/fs/btrfs/btrfs.c
+++ b/fs/btrfs/btrfs.c
@@ -9,6 +9,7 @@
#include <malloc.h>
#include <u-boot/uuid.h>
#include <linux/time.h>
+#include <fs.h>
#include "btrfs.h"
#include "crypto/hash.h"
#include "disk-io.h"
@@ -159,6 +160,97 @@ int btrfs_ls(const char *path)
return 0;
}
+struct btrfs_dir_stream {
+ struct fs_dir_stream parent;
+ struct fs_dirent dirent;
+ char *dirname;
+ u64 offset;
This doesn't look correct to me, for an opened dir, we should have at
least the root id or pointer, and an inode number.
Not just an @dirname and re-do the path resolution again and again.
In fact, I do not even think we should save @dirname here.
+};
+
+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);
You just discard the most important @root and @ino.
So what is the point here?
+ if (ret < 0)
+ return ret;
+ if (type != BTRFS_FT_DIR)
+ return -ENOTDIR;
+
+ dirs = calloc(1, sizeof(*dirs));
+ if (!dirs)
+ return -ENOMEM;
+ dirs->dirname = strdup(dirname);
+ if (!dirs->dirname) {
+ free(dirs);
+ return -ENOMEM;
+ }
+
+ *dirsp = (struct fs_dir_stream *)dirs;
+ return 0;
+}
+
+int btrfs_readdir(struct fs_dir_stream *fs_dirs, struct fs_dirent **dentp)
+{
+ struct btrfs_dir_stream *dirs = (struct btrfs_dir_stream *)fs_dirs;
+ struct btrfs_fs_info *fs_info = current_fs_info;
+ struct fs_dirent *dent = &dirs->dirent;
+ struct btrfs_root *root;
+ u64 ino;
+ u8 type;
+ int ret;
+
+ *dentp = NULL;
+ ASSERT(fs_info);
+
+ ret = btrfs_lookup_path(fs_info->fs_root, BTRFS_FIRST_FREE_OBJECTID,
+ dirs->dirname, &root, &ino, &type, 40);
No, doing the same path resolution again and again is not sane.
+ if (ret < 0)
+ return ret;
+ if (type != BTRFS_FT_DIR)
+ return -ENOTDIR;
+
+ memset(dent, 0, sizeof(*dent));
+ ret = btrfs_next_dir_entry(root, ino, &dirs->offset, dent->name,
+ sizeof(dent->name), &type);
+ if (ret < 0)
+ return ret;
+ if (ret > 0)
+ return -ENOENT;
+
+ switch (type) {
+ case BTRFS_FT_DIR:
+ dent->type = FS_DT_DIR;
+ break;
+ case BTRFS_FT_SYMLINK:
+ dent->type = FS_DT_LNK;
+ break;
+ default:
+ dent->type = FS_DT_REG;
+ break;
So it looks like u-boot only supports the above 3 types, and unlike
linux kernel the values doesn't match the btrfs internal ones.
In that case, I'd still prefer a proper convertor function.
[...]
+
+ *offset = key.offset + 1;
+ type = btrfs_dir_type(path.nodes[0], di);
+
+ /* XATTRs share the key space but are not directory entries. */
+ if (type == BTRFS_FT_XATTR) {
This doesn't looks correct again.
XATTR has their own keys, they should not show up among DIR_INDEX keys.
Thanks,
Qu
