[PATCH 3/3] ext4: show orphan file inode detail info

[Ye Bin <yebin@huaweicloud.com>]

From: Ye Bin <yebin10@huawei.com>

Support show inode information in orphan file.

Signed-off-by: Ye Bin <yebin10@huawei.com>
---
 fs/ext4/orphan.c | 115 ++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 94 insertions(+), 21 deletions(-)

diff --git a/fs/ext4/orphan.c b/fs/ext4/orphan.c
index 272de32d1a47..c01887fb496b 100644
--- a/fs/ext4/orphan.c
+++ b/fs/ext4/orphan.c
@@ -663,6 +663,11 @@ int ext4_orphan_file_empty(struct super_block *sb)
 struct ext4_proc_orphan {
 	struct ext4_inode_info cursor;
 	bool print_title;
+	struct ext4_orphan_info *oi;
+	int inodes_per_ob;
+	int block_idx;
+	int offset;
+	bool orphan_file;
 };
 
 static inline bool ext4_is_cursor(struct ext4_inode_info *inode)
@@ -683,24 +688,65 @@ static struct inode *ext4_list_next(struct list_head *head, struct list_head *p)
 	return NULL;
 }
 
+static struct inode *ext4_orphan_file_next(struct ext4_proc_orphan *s,
+					   struct super_block *sb)
+{
+	struct inode *inode;
+	struct ext4_orphan_info *oi = s->oi;
+
+	for (; s->block_idx < oi->of_blocks; s->block_idx++) {
+		__le32 *bdata = (__le32 *)(oi->of_binfo[s->block_idx].ob_bh->b_data);
+
+		if (atomic_read(&oi->of_binfo[s->block_idx].ob_free_entries) ==
+		    s->inodes_per_ob) {
+			s->offset = 0;
+			continue;
+		}
+		for (; s->offset < s->inodes_per_ob; s->offset++) {
+			if (!bdata[s->offset])
+				continue;
+			inode = ext4_iget(sb, le32_to_cpu(bdata[s->offset]),
+					  EXT4_IGET_NORMAL);
+			if (IS_ERR(inode))
+				continue;
+			s->offset++;
+			return inode;
+		}
+		s->offset = 0;
+	}
+
+	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;
+	void *ret;
 
-	mutex_lock(&sbi->s_orphan_lock);
+	if (!s->orphan_file) {
+		mutex_lock(&sbi->s_orphan_lock);
+		if (!*pos)
+			prev = &sbi->s_orphan;
+		else
+			prev = &s->cursor.i_orphan;
 
-	if (!*pos) {
-		prev = &sbi->s_orphan;
-	} else {
-		prev = &s->cursor.i_orphan;
-		if (list_empty(prev))
+		if (!list_empty(prev)) {
+			ret = ext4_list_next(&sbi->s_orphan, prev);
+			if (ret)
+				return ret;
+		}
+
+		if (!s->oi)
 			return NULL;
+		list_del_init(&s->cursor.i_orphan);
+		mutex_unlock(&sbi->s_orphan_lock);
+		s->orphan_file = true;
 	}
 
-	return ext4_list_next(&sbi->s_orphan, prev);
+	return ext4_orphan_file_next(s, sb);
 }
 
 static void *ext4_orphan_seq_next(struct seq_file *seq, void *v, loff_t *pos)
@@ -708,10 +754,26 @@ static void *ext4_orphan_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 	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;
+	void *ret;
 
 	++*pos;
 
-	return ext4_list_next(&sbi->s_orphan, &EXT4_I(inode)->i_orphan);
+	if (!s->orphan_file) {
+		ret = ext4_list_next(&sbi->s_orphan, &EXT4_I(inode)->i_orphan);
+		if (ret)
+			return ret;
+		if (!s->oi)
+			return NULL;
+		list_del_init(&s->cursor.i_orphan);
+		mutex_unlock(&sbi->s_orphan_lock);
+		s->orphan_file = true;
+		v = NULL;
+	}
+
+	iput(v);
+
+	return ext4_orphan_file_next(s, sb);
 }
 
 static void ext4_show_filename(struct seq_file *seq, struct inode *inode)
@@ -758,12 +820,16 @@ static void ext4_orphan_seq_stop(struct seq_file *seq, void *v)
 	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);
+	if (!s->orphan_file) {
+		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);
+		mutex_unlock(&sbi->s_orphan_lock);
+	} else {
+		iput(v);
+	}
 }
 
 const struct seq_operations ext4_orphan_seq_ops = {
@@ -777,16 +843,21 @@ static int ext4_seq_orphan_open(struct inode *inode, struct file *file)
 {
 	int rc;
 	struct seq_file *m;
-	struct ext4_proc_orphan *private;
+	struct ext4_proc_orphan *s;
 
 	rc = seq_open_private(file, &ext4_orphan_seq_ops,
 			      sizeof(struct ext4_proc_orphan));
 	if (!rc) {
+		struct super_block *sb = pde_data(file_inode(file));
 		m = file->private_data;
-		private = m->private;
-		INIT_LIST_HEAD(&private->cursor.i_orphan);
-		private->cursor.vfs_inode.i_ino = 0;
-		private->print_title = true;
+		s = m->private;
+		INIT_LIST_HEAD(&s->cursor.i_orphan);
+		s->cursor.vfs_inode.i_ino = 0;
+		s->print_title = true;
+		if (ext4_has_feature_orphan_file(sb)) {
+			s->oi = &EXT4_SB(sb)->s_orphan_info;
+			s->inodes_per_ob = ext4_inodes_per_orphan_block(sb);
+		}
 	}
 
 	return rc;
@@ -798,9 +869,11 @@ static int ext4_seq_orphan_release(struct inode *inode, struct file *file)
 	struct ext4_proc_orphan *s = seq->private;
 	struct ext4_sb_info *sbi = EXT4_SB(pde_data(inode));
 
-	mutex_lock(&sbi->s_orphan_lock);
-	list_del(&s->cursor.i_orphan);
-	mutex_unlock(&sbi->s_orphan_lock);
+	if (!s->orphan_file) {
+		mutex_lock(&sbi->s_orphan_lock);
+		list_del(&s->cursor.i_orphan);
+		mutex_unlock(&sbi->s_orphan_lock);
+	}
 
 	return seq_release_private(inode, file);
 }
-- 
2.34.1