Re: [PATCH 2/3] ext4: show inode orphan list detail information

[Andreas Dilger <adilger@dilger.ca>]

On Apr 3, 2026, at 02:25, Ye Bin <yebin@huaweicloud.com> wrote:
> 
> From: Ye Bin <yebin10@huawei.com>
> 
> Some inodes added to the orphan list are due to truncation, while others
> are due to deletion.Therefore, we printed the information of inode as
> follows: inode number/i_nlink/i_size/i_blocks/projid/file path. By using
> this information, it is possible to quickly identify files that have been
> deleted but are still being referenced.

Since the format of this output is still flexible, I would request that
it be formatted in a way that is more easily understood and parsed instead
of just an unformatted list of numbers.

Using YAML combines both human and machine readable properties, without
a lot of overhead, something like:

- ino: INUM, link: NLINK, size: SIZE, blocks: BLOCKS, proj: PROJID, path: "PATH"
- ino: ...
- ino: ...

The PATH should derfinitely be quoted to avoid issues with spaces and
other special characters in the filename.

Cheers, Andreas

> 
> Signed-off-by: Ye Bin <yebin10@huawei.com>
> ---
> fs/ext4/orphan.c | 88 ++++++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 86 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/ext4/orphan.c b/fs/ext4/orphan.c
> index 1d231aeaf282..272de32d1a47 100644
> --- a/fs/ext4/orphan.c
> +++ b/fs/ext4/orphan.c
> @@ -662,25 +662,108 @@ int ext4_orphan_file_empty(struct super_block *sb)
> 
> struct ext4_proc_orphan {
> struct ext4_inode_info cursor;
> + bool print_title;
> };
> 
> -static void *ext4_orphan_seq_start(struct seq_file *seq, loff_t *pos)
> +static inline bool ext4_is_cursor(struct ext4_inode_info *inode)
> +{
> + return (inode->vfs_inode.i_ino == 0);
> +}
> +
> +static struct inode *ext4_list_next(struct list_head *head, struct list_head *p)
> {
> + struct ext4_inode_info *inode;
> +
> + list_for_each_continue(p, head) {
> + inode = list_entry(p, typeof(*inode), i_orphan);
> + if (!ext4_is_cursor(inode))
> + return &inode->vfs_inode;
> + }
> +
> return NULL;
> }
> 
> +static void *ext4_orphan_seq_start(struct seq_file *seq, loff_t *pos)
> +{
> + struct ext4_proc_orphan *s = seq->private;
> + struct super_block *sb = pde_data(file_inode(seq->file));
> + struct ext4_sb_info *sbi = EXT4_SB(sb);
> + struct list_head *prev;
> +
> + mutex_lock(&sbi->s_orphan_lock);
> +
> + if (!*pos) {
> + prev = &sbi->s_orphan;
> + } else {
> + prev = &s->cursor.i_orphan;
> + if (list_empty(prev))
> + return NULL;
> + }
> +
> + return ext4_list_next(&sbi->s_orphan, prev);
> +}
> +
> static void *ext4_orphan_seq_next(struct seq_file *seq, void *v, loff_t *pos)
> {
> - return NULL;
> + struct super_block *sb = pde_data(file_inode(seq->file));
> + struct ext4_sb_info *sbi = EXT4_SB(sb);
> + struct inode *inode = v;
> +
> + ++*pos;
> +
> + return ext4_list_next(&sbi->s_orphan, &EXT4_I(inode)->i_orphan);
> +}
> +
> +static void ext4_show_filename(struct seq_file *seq, struct inode *inode)
> +{
> + struct dentry *dentry;
> +
> + dentry = d_find_alias(inode);
> + if (!dentry)
> + dentry = d_find_any_alias(inode);
> +
> + if (dentry)
> + seq_dentry(seq, dentry, "\t\n\\");
> + else
> + seq_puts(seq, "unknown");
> +
> + dput(dentry);
> + seq_putc(seq, '\n');
> }
> 
> static int ext4_orphan_seq_show(struct seq_file *seq, void *v)
> {
> + struct inode *inode = v;
> + struct ext4_proc_orphan *s = seq->private;
> +
> + if (s->print_title) {
> + seq_puts(seq, "INO\tNLINK\tSIZE\tBLOCKS\tPROJID\tPATH\n");
> + s->print_title = false;
> + }
> +
> + seq_printf(seq, "%llu\t%u\t%llu\t%llu\t%u\t",
> +   inode->i_ino, inode->i_nlink,
> +   i_size_read(inode), inode->i_blocks,
> +   __kprojid_val(EXT4_I(inode)->i_projid));
> +
> + ext4_show_filename(seq, inode);
> +
> return 0;
> }
> 
> static void ext4_orphan_seq_stop(struct seq_file *seq, void *v)
> {
> + struct super_block *sb = pde_data(file_inode(seq->file));
> + struct ext4_sb_info *sbi = EXT4_SB(sb);
> + struct inode *inode = v;
> + struct ext4_proc_orphan *s = seq->private;
> +
> + if (inode)
> + list_move_tail(&s->cursor.i_orphan, &EXT4_I(inode)->i_orphan);
> + else
> + list_del_init(&s->cursor.i_orphan);
> +
> + mutex_unlock(&sbi->s_orphan_lock);
> }
> 
> const struct seq_operations ext4_orphan_seq_ops = {
> @@ -703,6 +786,7 @@ static int ext4_seq_orphan_open(struct inode *inode, struct file *file)
> private = m->private;
> INIT_LIST_HEAD(&private->cursor.i_orphan);
> private->cursor.vfs_inode.i_ino = 0;
> + private->print_title = true;
> }
> 
> return rc;
> -- 
> 2.34.1
> 


Cheers, Andreas