On Fri, Jul 05, 2024 at 03:20:06PM GMT, Hongbo Li wrote:
> The isize of directory is 0 in bcachefs if the directory is empty.
> With more child dirents created, its size ought to change. Many
> other filesystems changed as that (ie. xfs and btrfs). And many of
> them changed as the size of child dirent name. Although the directory
> size may not seem to convey much, we can still give it some meaning.
>
> The formula of dentry size as follow:
> occupied_size = 40 + ALIGN(9 + namelen, 8)
>
> Signed-off-by: Hongbo Li <[email protected]>
I like it.
It's going to need more work though; it'll be a new on disk format
version, and fsck needs to know how to sum up dirents and check i_size -
which won't be bad, since we already have to sum up child directories
for i_nlink.
> ---
> fs/bcachefs/dirent.h | 5 +++++
> fs/bcachefs/fs-common.c | 11 +++++++++++
> fs/bcachefs/fs.c | 13 ++++++++-----
> 3 files changed, 24 insertions(+), 5 deletions(-)
>
> diff --git a/fs/bcachefs/dirent.h b/fs/bcachefs/dirent.h
> index 24037e6e0a09..16b0c89970ac 100644
> --- a/fs/bcachefs/dirent.h
> +++ b/fs/bcachefs/dirent.h
> @@ -32,6 +32,11 @@ static inline unsigned dirent_val_u64s(unsigned len)
> sizeof(u64));
> }
>
> +static inline unsigned int dirent_occupied_size(const struct qstr *name)
> +{
> + return (BKEY_U64s + dirent_val_u64s(name->len)) * sizeof(u64);
> +}
> +
> int bch2_dirent_read_target(struct btree_trans *, subvol_inum,
> struct bkey_s_c_dirent, subvol_inum *);
>
> diff --git a/fs/bcachefs/fs-common.c b/fs/bcachefs/fs-common.c
> index 508d029ac53d..2d5db8c530a2 100644
> --- a/fs/bcachefs/fs-common.c
> +++ b/fs/bcachefs/fs-common.c
> @@ -153,6 +153,7 @@ int bch2_create_trans(struct btree_trans *trans,
> if (is_subdir_for_nlink(new_inode))
> dir_u->bi_nlink++;
> dir_u->bi_mtime = dir_u->bi_ctime = now;
> + dir_u->bi_size += dirent_occupied_size(name);
>
> ret = bch2_inode_write(trans, &dir_iter, dir_u);
> if (ret)
> @@ -217,6 +218,7 @@ int bch2_link_trans(struct btree_trans *trans,
> }
>
> dir_u->bi_mtime = dir_u->bi_ctime = now;
> + dir_u->bi_size += dirent_occupied_size(name);
>
> dir_hash = bch2_hash_info_init(c, dir_u);
>
> @@ -319,6 +321,7 @@ int bch2_unlink_trans(struct btree_trans *trans,
>
> dir_u->bi_mtime = dir_u->bi_ctime = inode_u->bi_ctime = now;
> dir_u->bi_nlink -= is_subdir_for_nlink(inode_u);
> + dir_u->bi_size -= dirent_occupied_size(name);
>
> ret = bch2_hash_delete_at(trans, bch2_dirent_hash_desc,
> &dir_hash, &dirent_iter,
> @@ -457,6 +460,14 @@ int bch2_rename_trans(struct btree_trans *trans,
> goto err;
> }
>
> + if (mode == BCH_RENAME) {
> + src_dir_u->bi_size -= dirent_occupied_size(src_name);
> + dst_dir_u->bi_size += dirent_occupied_size(dst_name);
> + }
> +
> + if (mode == BCH_RENAME_OVERWRITE)
> + src_dir_u->bi_size -= dirent_occupied_size(src_name);
> +
> if (src_inode_u->bi_parent_subvol)
> src_inode_u->bi_parent_subvol = dst_dir.subvol;
>
> diff --git a/fs/bcachefs/fs.c b/fs/bcachefs/fs.c
> index fd01a5402c28..6c7496d40521 100644
> --- a/fs/bcachefs/fs.c
> +++ b/fs/bcachefs/fs.c
> @@ -65,6 +65,9 @@ void bch2_inode_update_after_write(struct btree_trans
> *trans,
> i_gid_write(&inode->v, bi->bi_gid);
> inode->v.i_mode = bi->bi_mode;
>
> + if (fields & ATTR_SIZE)
> + i_size_write(&inode->v, bi->bi_size);
> +
> if (fields & ATTR_ATIME)
> inode_set_atime_to_ts(&inode->v, bch2_time_to_timespec(c,
> bi->bi_atime));
> if (fields & ATTR_MTIME)
> @@ -369,7 +372,7 @@ __bch2_create(struct mnt_idmap *idmap,
>
> if (!(flags & BCH_CREATE_TMPFILE)) {
> bch2_inode_update_after_write(trans, dir, &dir_u,
> - ATTR_MTIME|ATTR_CTIME);
> + ATTR_MTIME|ATTR_CTIME|ATTR_SIZE);
> mutex_unlock(&dir->ei_update_lock);
> }
>
> @@ -525,7 +528,7 @@ static int __bch2_link(struct bch_fs *c,
>
> if (likely(!ret)) {
> bch2_inode_update_after_write(trans, dir, &dir_u,
> - ATTR_MTIME|ATTR_CTIME);
> + ATTR_MTIME|ATTR_CTIME|ATTR_SIZE);
> bch2_inode_update_after_write(trans, inode, &inode_u,
> ATTR_CTIME);
> }
>
> @@ -577,7 +580,7 @@ int __bch2_unlink(struct inode *vdir, struct dentry
> *dentry,
> goto err;
>
> bch2_inode_update_after_write(trans, dir, &dir_u,
> - ATTR_MTIME|ATTR_CTIME);
> + ATTR_MTIME|ATTR_CTIME|ATTR_SIZE);
> bch2_inode_update_after_write(trans, inode, &inode_u,
> ATTR_MTIME);
>
> @@ -724,11 +727,11 @@ static int bch2_rename2(struct mnt_idmap *idmap,
> dst_inode->v.i_ino != dst_inode_u.bi_inum);
>
> bch2_inode_update_after_write(trans, src_dir, &src_dir_u,
> - ATTR_MTIME|ATTR_CTIME);
> + ATTR_MTIME|ATTR_CTIME|ATTR_SIZE);
>
> if (src_dir != dst_dir)
> bch2_inode_update_after_write(trans, dst_dir, &dst_dir_u,
> - ATTR_MTIME|ATTR_CTIME);
> + ATTR_MTIME|ATTR_CTIME|ATTR_SIZE);
>
> bch2_inode_update_after_write(trans, src_inode, &src_inode_u,
> ATTR_CTIME);
> --
> 2.34.1
>
