btrfs_readdir() zeroes the dirent and fills in only the name and the
type, so dent->size stays 0 and every file is listed as zero bytes:
=> ls host 0 /
0 f_192k.bin
0 small_3k.bin
Reads themselves are fine, since btrfs_read() takes the size from
btrfs_size(), which does its own inode item lookup. It affects EFI
too: dir_read() in lib/efi_loader/efi_file.c copies dent->size into
both file_size and physical_size, so an EFI application enumerating a
directory on btrfs sees every file as empty, which is the generic-code
path Alexey's readdir series moves btrfs onto.
The custom listing that fs_ls_generic() replaced looked the inode item
up and printed the real size, and every other filesystem in the tree
fills dent->size in its own readdir: ext4fs.c:327, exfat io.c:805,
erofs fs.c:186, squashfs sqfs.c:1095 and fat.c:1555.
btrfs_next_dir_entry() already has the dir item mapped, so read the
key it points at while we are there and hand it back to the caller,
and use that to reach the inode item. A subvolume entry points at a
root item instead and has no size of its own, so leave that one at 0.
=> ls host 0 /
196608 f_192k.bin
3000 small_3k.bin
Fixes: 31cf3f177823 ("fs: btrfs: use fs_ls_generic() and drop custom
implementation")
Signed-off-by: Cole Munz <[email protected]>
---
fs/btrfs/btrfs.c | 24 +++++++++++++++++++++++-
fs/btrfs/ctree.h | 3 ++-
fs/btrfs/dir-item.c | 7 ++++++-
3 files changed, 31 insertions(+), 3 deletions(-)
diff --git a/fs/btrfs/btrfs.c b/fs/btrfs/btrfs.c
index e663dda12e80..b2856be0662f 100644
--- a/fs/btrfs/btrfs.c
+++ b/fs/btrfs/btrfs.c
@@ -93,7 +93,10 @@ 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_inode_item *ii;
struct btrfs_root *root;
+ struct btrfs_path path;
+ struct btrfs_key location;
struct btrfs_key key;
u8 type;
int ret;
@@ -110,13 +113,32 @@ int btrfs_readdir(struct fs_dir_stream *fs_dirs, struct
fs_dirent **dentp)
memset(dent, 0, sizeof(*dent));
ret = btrfs_next_dir_entry(root, dirs->ino, &dirs->offset, dent->name,
- sizeof(dent->name), &type);
+ sizeof(dent->name), &type, &location);
if (ret < 0)
return ret;
if (ret > 0)
return -ENOENT;
dent->type = btrfs_dirent_type_to_fs_type(type);
+
+ /*
+ * A subvolume entry points at a root item rather than an inode, and
+ * has no size of its own. Everything else carries one, and the fs
+ * layer prints it, so look it up.
+ */
+ if (location.type == BTRFS_INODE_ITEM_KEY) {
+ btrfs_init_path(&path);
+ ret = btrfs_search_slot(NULL, root, &location, &path, 0, 0);
+ if (ret == 0) {
+ ii = btrfs_item_ptr(path.nodes[0], path.slots[0],
+ struct btrfs_inode_item);
+ dent->size = btrfs_inode_size(path.nodes[0], ii);
+ }
+ btrfs_release_path(&path);
+ if (ret < 0)
+ return ret;
+ }
+
*dentp = dent;
return 0;
}
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 3fa9a8c9c020..cd3fd669f9ae 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1221,7 +1221,8 @@ struct btrfs_dir_item *btrfs_lookup_dir_item(struct
btrfs_trans_handle *trans,
const char *name, int name_len,
int mod);
int btrfs_next_dir_entry(struct btrfs_root *root, u64 ino, u64 *offset,
- char *namebuf, int namebuf_len, u8 *ftype);
+ char *namebuf, int namebuf_len, u8 *ftype,
+ struct btrfs_key *location);
/* inode.c */
int btrfs_lookup_path(struct btrfs_root *root, u64 ino, const char *filename,
struct btrfs_root **root_ret, u64 *ino_ret,
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index c7b87d60d986..6edda34818b8 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -126,12 +126,16 @@ struct btrfs_dir_item *btrfs_lookup_dir_item(struct
btrfs_trans_handle *trans,
* @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
+ * @location: receives the key the entry points at, so the caller can
+ * reach the inode item without searching for the name
+ * again
*
* 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)
+ char *namebuf, int namebuf_len, u8 *ftype,
+ struct btrfs_key *location)
{
struct btrfs_path path;
struct btrfs_key key;
@@ -180,6 +184,7 @@ int btrfs_next_dir_entry(struct btrfs_root *root, u64 ino,
u64 *offset,
(unsigned long)(di + 1), name_len);
namebuf[name_len] = '\0';
*ftype = btrfs_dir_type(path.nodes[0], di);
+ btrfs_dir_item_key_to_cpu(path.nodes[0], di, location);
ret = 0;
out:
--
2.55.0
