[PATCH 0/5 v5] ext4: Speedup orphan file handling

[PATCH 0/5 v5] ext4: Speedup orphan file handling

[Jan Kara]

  Hello,

Here is a fourth version of my series to speed up orphan inode handling in
ext4.

Orphan inode handling in ext4 is a bottleneck for workloads which heavily
excercise truncate / unlink of small files as they contend on global
s_orphan_mutex (when you have fast enough storage). This patch set implements
new way of handling orphan inodes - instead of using a linked list, we store
inode numbers of orphaned inodes in a file which is possible to implement in a
more scalable manner than linked list manipulations. See description of patch
3/5 for more details.

The patch set achieves significant gains both for a micro benchmark stressing
orphan inode handling (truncating file byte-by-byte, several threads in
parallel) and for reaim creat_clo workload. I'm happy for any review, thoughts,
ideas about the patches. I have also implemented full support in e2fsprogs
which I'll send separately.

								Honza

[1] https://lore.kernel.org/lkml/20210227120804.GB22871@xsang-OptiPlex-9020/

Changes since v4:
* Rebased on top of v5.14-rc5
* Updated commit message of patch 1/5
* Added Reviewed-by tags from Ted

Changes since v3:
* Added documentation about on-disk format changes
* Add physical block number into orphan block checksum
* Improve some sanity checks, handling of corrupted orphan file
* Improved some changelogs

Changes since v2:
* Updated some comments
* Rebased onto 5.13-rc5
* Change orphan file inode from a fixed inode number to inode number stored
  in the superblock

Changes since v1:
* orphan blocks have now magic numbers
* split out orphan handling to a separate source file
* some smaller updates according to review

Previous versions:
Link: https://lore.kernel.org/linux-ext4/20210712154009.9290-1-jack@suse.cz/ #v4
Link: https://lore.kernel.org/linux-ext4/20210616105655.5129-1-jack@suse.cz/ #v3
Link: https://lore.kernel.org/linux-ext4/1432293717-24010-1-git-send-email-jack@suse.cz/ #v2

[PATCH 1/5] ext4: Support for checksumming from journal triggers

[Jan Kara]

JBD2 layer support triggers which are called when journaling layer moves
buffer to a certain state. We can use the frozen trigger, which gets
called when buffer data is frozen and about to be written out to the
journal, to compute block checksums for some buffer types (similarly as
does ocfs2). This avoids unnecessary repeated recomputation of the
checksum (at the cost of larger window where memory corruption won't be
caught by checksumming) and is even necessary when there are
unsynchronized updaters of the checksummed data.

So add superblock and journal trigger type arguments to
ext4_journal_get_write_access() and ext4_journal_get_create_access() so
that frozen triggers can be set accordingly. Also add inode argument to
ext4_walk_page_buffers() and all the callbacks used with that function
for the same purpose. This patch is mostly only a change of prototype of
the above mentioned functions and a few small helpers. Real checksumming
will come later.

Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/ext4/ext4.h        | 26 ++++++++++++--
 fs/ext4/ext4_jbd2.c   | 43 +++++++++++++++-------
 fs/ext4/ext4_jbd2.h   | 18 ++++++----
 fs/ext4/extents.c     | 12 ++++---
 fs/ext4/file.c        |  3 +-
 fs/ext4/ialloc.c      | 19 ++++++----
 fs/ext4/indirect.c    | 15 +++++---
 fs/ext4/inline.c      | 26 +++++++++-----
 fs/ext4/inode.c       | 84 +++++++++++++++++++++++++------------------
 fs/ext4/ioctl.c       |  4 ++-
 fs/ext4/mballoc.c     | 15 ++++----
 fs/ext4/namei.c       | 40 +++++++++++++--------
 fs/ext4/resize.c      | 38 ++++++++++++--------
 fs/ext4/super.c       | 16 ++++++++-
 fs/ext4/xattr.c       | 26 +++++++++-----
 fs/jbd2/transaction.c |  2 +-
 16 files changed, 259 insertions(+), 128 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 3c51e243450d..c3cd7faa6cf2 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1447,6 +1447,24 @@ struct ext4_super_block {
 
 #define EXT4_ENC_UTF8_12_1	1
 
+/* Types of ext4 journal triggers */
+enum ext4_journal_trigger_type {
+	EXT4_JTR_NONE	/* This must be the last entry for indexing to work! */
+};
+
+#define EXT4_JOURNAL_TRIGGER_COUNT EXT4_JTR_NONE
+
+struct ext4_journal_trigger {
+	struct jbd2_buffer_trigger_type tr_triggers;
+	struct super_block *sb;
+};
+
+static inline struct ext4_journal_trigger *EXT4_TRIGGER(
+				struct jbd2_buffer_trigger_type *trigger)
+{
+	return container_of(trigger, struct ext4_journal_trigger, tr_triggers);
+}
+
 /*
  * fourth extended-fs super-block data in memory
  */
@@ -1625,6 +1643,9 @@ struct ext4_sb_info {
 	struct mb_cache *s_ea_inode_cache;
 	spinlock_t s_es_lock ____cacheline_aligned_in_smp;
 
+	/* Journal triggers for checksum computation */
+	struct ext4_journal_trigger s_journal_triggers[EXT4_JOURNAL_TRIGGER_COUNT];
+
 	/* Ratelimit ext4 messages. */
 	struct ratelimit_state s_err_ratelimit_state;
 	struct ratelimit_state s_warning_ratelimit_state;
@@ -2920,13 +2941,14 @@ int ext4_get_block(struct inode *inode, sector_t iblock,
 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
 			   struct buffer_head *bh, int create);
 int ext4_walk_page_buffers(handle_t *handle,
+			   struct inode *inode,
 			   struct buffer_head *head,
 			   unsigned from,
 			   unsigned to,
 			   int *partial,
-			   int (*fn)(handle_t *handle,
+			   int (*fn)(handle_t *handle, struct inode *inode,
 				     struct buffer_head *bh));
-int do_journal_get_write_access(handle_t *handle,
+int do_journal_get_write_access(handle_t *handle, struct inode *inode,
 				struct buffer_head *bh);
 #define FALL_BACK_TO_NONDELALLOC 1
 #define CONVERT_INLINE_DATA	 2
diff --git a/fs/ext4/ext4_jbd2.c b/fs/ext4/ext4_jbd2.c
index b60f0152ea57..6def7339056d 100644
--- a/fs/ext4/ext4_jbd2.c
+++ b/fs/ext4/ext4_jbd2.c
@@ -218,9 +218,11 @@ static void ext4_check_bdev_write_error(struct super_block *sb)
 }
 
 int __ext4_journal_get_write_access(const char *where, unsigned int line,
-				    handle_t *handle, struct buffer_head *bh)
+				    handle_t *handle, struct super_block *sb,
+				    struct buffer_head *bh,
+				    enum ext4_journal_trigger_type trigger_type)
 {
-	int err = 0;
+	int err;
 
 	might_sleep();
 
@@ -229,11 +231,18 @@ int __ext4_journal_get_write_access(const char *where, unsigned int line,
 
 	if (ext4_handle_valid(handle)) {
 		err = jbd2_journal_get_write_access(handle, bh);
-		if (err)
+		if (err) {
 			ext4_journal_abort_handle(where, line, __func__, bh,
 						  handle, err);
+			return err;
+		}
 	}
-	return err;
+	if (trigger_type == EXT4_JTR_NONE || !ext4_has_metadata_csum(sb))
+		return 0;
+	BUG_ON(trigger_type >= EXT4_JOURNAL_TRIGGER_COUNT);
+	jbd2_journal_set_triggers(bh,
+		&EXT4_SB(sb)->s_journal_triggers[trigger_type].tr_triggers);
+	return 0;
 }
 
 /*
@@ -301,17 +310,27 @@ int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
 }
 
 int __ext4_journal_get_create_access(const char *where, unsigned int line,
-				handle_t *handle, struct buffer_head *bh)
+				handle_t *handle, struct super_block *sb,
+				struct buffer_head *bh,
+				enum ext4_journal_trigger_type trigger_type)
 {
-	int err = 0;
+	int err;
 
-	if (ext4_handle_valid(handle)) {
-		err = jbd2_journal_get_create_access(handle, bh);
-		if (err)
-			ext4_journal_abort_handle(where, line, __func__,
-						  bh, handle, err);
+	if (!ext4_handle_valid(handle))
+		return 0;
+
+	err = jbd2_journal_get_create_access(handle, bh);
+	if (err) {
+		ext4_journal_abort_handle(where, line, __func__, bh, handle,
+					  err);
+		return err;
 	}
-	return err;
+	if (trigger_type == EXT4_JTR_NONE || !ext4_has_metadata_csum(sb))
+		return 0;
+	BUG_ON(trigger_type >= EXT4_JOURNAL_TRIGGER_COUNT);
+	jbd2_journal_set_triggers(bh,
+		&EXT4_SB(sb)->s_journal_triggers[trigger_type].tr_triggers);
+	return 0;
 }
 
 int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
diff --git a/fs/ext4/ext4_jbd2.h b/fs/ext4/ext4_jbd2.h
index 0d2fa423b7ad..0e4fa644df01 100644
--- a/fs/ext4/ext4_jbd2.h
+++ b/fs/ext4/ext4_jbd2.h
@@ -231,26 +231,32 @@ int ext4_expand_extra_isize(struct inode *inode,
  * Wrapper functions with which ext4 calls into JBD.
  */
 int __ext4_journal_get_write_access(const char *where, unsigned int line,
-				    handle_t *handle, struct buffer_head *bh);
+				    handle_t *handle, struct super_block *sb,
+				    struct buffer_head *bh,
+				    enum ext4_journal_trigger_type trigger_type);
 
 int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
 		  int is_metadata, struct inode *inode,
 		  struct buffer_head *bh, ext4_fsblk_t blocknr);
 
 int __ext4_journal_get_create_access(const char *where, unsigned int line,
-				handle_t *handle, struct buffer_head *bh);
+				handle_t *handle, struct super_block *sb,
+				struct buffer_head *bh,
+				enum ext4_journal_trigger_type trigger_type);
 
 int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
 				 handle_t *handle, struct inode *inode,
 				 struct buffer_head *bh);
 
-#define ext4_journal_get_write_access(handle, bh) \
-	__ext4_journal_get_write_access(__func__, __LINE__, (handle), (bh))
+#define ext4_journal_get_write_access(handle, sb, bh, trigger_type) \
+	__ext4_journal_get_write_access(__func__, __LINE__, (handle), (sb), \
+					(bh), (trigger_type))
 #define ext4_forget(handle, is_metadata, inode, bh, block_nr) \
 	__ext4_forget(__func__, __LINE__, (handle), (is_metadata), (inode), \
 		      (bh), (block_nr))
-#define ext4_journal_get_create_access(handle, bh) \
-	__ext4_journal_get_create_access(__func__, __LINE__, (handle), (bh))
+#define ext4_journal_get_create_access(handle, sb, bh, trigger_type) \
+	__ext4_journal_get_create_access(__func__, __LINE__, (handle), (sb), \
+					 (bh), (trigger_type))
 #define ext4_handle_dirty_metadata(handle, inode, bh) \
 	__ext4_handle_dirty_metadata(__func__, __LINE__, (handle), (inode), \
 				     (bh))
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 92ad64b89d9b..7edc921107ac 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -139,7 +139,8 @@ static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
 	if (path->p_bh) {
 		/* path points to block */
 		BUFFER_TRACE(path->p_bh, "get_write_access");
-		return ext4_journal_get_write_access(handle, path->p_bh);
+		return ext4_journal_get_write_access(handle, inode->i_sb,
+						     path->p_bh, EXT4_JTR_NONE);
 	}
 	/* path points to leaf/index in inode body */
 	/* we use in-core data, no need to protect them */
@@ -1082,7 +1083,8 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 	}
 	lock_buffer(bh);
 
-	err = ext4_journal_get_create_access(handle, bh);
+	err = ext4_journal_get_create_access(handle, inode->i_sb, bh,
+					     EXT4_JTR_NONE);
 	if (err)
 		goto cleanup;
 
@@ -1160,7 +1162,8 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 		}
 		lock_buffer(bh);
 
-		err = ext4_journal_get_create_access(handle, bh);
+		err = ext4_journal_get_create_access(handle, inode->i_sb, bh,
+						     EXT4_JTR_NONE);
 		if (err)
 			goto cleanup;
 
@@ -1286,7 +1289,8 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
 		return -ENOMEM;
 	lock_buffer(bh);
 
-	err = ext4_journal_get_create_access(handle, bh);
+	err = ext4_journal_get_create_access(handle, inode->i_sb, bh,
+					     EXT4_JTR_NONE);
 	if (err) {
 		unlock_buffer(bh);
 		goto out;
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 816dedcbd541..eda12bc50592 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -822,7 +822,8 @@ static int ext4_sample_last_mounted(struct super_block *sb,
 	if (IS_ERR(handle))
 		goto out;
 	BUFFER_TRACE(sbi->s_sbh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, sbi->s_sbh);
+	err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,
+					    EXT4_JTR_NONE);
 	if (err)
 		goto out_journal;
 	lock_buffer(sbi->s_sbh);
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index e89fc0f770b0..f73e5eb43eae 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -300,7 +300,8 @@ void ext4_free_inode(handle_t *handle, struct inode *inode)
 	}
 
 	BUFFER_TRACE(bitmap_bh, "get_write_access");
-	fatal = ext4_journal_get_write_access(handle, bitmap_bh);
+	fatal = ext4_journal_get_write_access(handle, sb, bitmap_bh,
+					      EXT4_JTR_NONE);
 	if (fatal)
 		goto error_return;
 
@@ -308,7 +309,8 @@ void ext4_free_inode(handle_t *handle, struct inode *inode)
 	gdp = ext4_get_group_desc(sb, block_group, &bh2);
 	if (gdp) {
 		BUFFER_TRACE(bh2, "get_write_access");
-		fatal = ext4_journal_get_write_access(handle, bh2);
+		fatal = ext4_journal_get_write_access(handle, sb, bh2,
+						      EXT4_JTR_NONE);
 	}
 	ext4_lock_group(sb, block_group);
 	cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
@@ -1085,7 +1087,8 @@ struct inode *__ext4_new_inode(struct user_namespace *mnt_userns,
 			}
 		}
 		BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
-		err = ext4_journal_get_write_access(handle, inode_bitmap_bh);
+		err = ext4_journal_get_write_access(handle, sb, inode_bitmap_bh,
+						    EXT4_JTR_NONE);
 		if (err) {
 			ext4_std_error(sb, err);
 			goto out;
@@ -1127,7 +1130,8 @@ struct inode *__ext4_new_inode(struct user_namespace *mnt_userns,
 	}
 
 	BUFFER_TRACE(group_desc_bh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, group_desc_bh);
+	err = ext4_journal_get_write_access(handle, sb, group_desc_bh,
+					    EXT4_JTR_NONE);
 	if (err) {
 		ext4_std_error(sb, err);
 		goto out;
@@ -1144,7 +1148,8 @@ struct inode *__ext4_new_inode(struct user_namespace *mnt_userns,
 			goto out;
 		}
 		BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
-		err = ext4_journal_get_write_access(handle, block_bitmap_bh);
+		err = ext4_journal_get_write_access(handle, sb, block_bitmap_bh,
+						    EXT4_JTR_NONE);
 		if (err) {
 			brelse(block_bitmap_bh);
 			ext4_std_error(sb, err);
@@ -1583,8 +1588,8 @@ int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
 	num = sbi->s_itb_per_group - used_blks;
 
 	BUFFER_TRACE(group_desc_bh, "get_write_access");
-	ret = ext4_journal_get_write_access(handle,
-					    group_desc_bh);
+	ret = ext4_journal_get_write_access(handle, sb, group_desc_bh,
+					    EXT4_JTR_NONE);
 	if (ret)
 		goto err_out;
 
diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c
index a7bc6ad656a9..89efa78ed4b2 100644
--- a/fs/ext4/indirect.c
+++ b/fs/ext4/indirect.c
@@ -354,7 +354,8 @@ static int ext4_alloc_branch(handle_t *handle,
 		}
 		lock_buffer(bh);
 		BUFFER_TRACE(bh, "call get_create_access");
-		err = ext4_journal_get_create_access(handle, bh);
+		err = ext4_journal_get_create_access(handle, ar->inode->i_sb,
+						     bh, EXT4_JTR_NONE);
 		if (err) {
 			unlock_buffer(bh);
 			goto failed;
@@ -429,7 +430,8 @@ static int ext4_splice_branch(handle_t *handle,
 	 */
 	if (where->bh) {
 		BUFFER_TRACE(where->bh, "get_write_access");
-		err = ext4_journal_get_write_access(handle, where->bh);
+		err = ext4_journal_get_write_access(handle, ar->inode->i_sb,
+						    where->bh, EXT4_JTR_NONE);
 		if (err)
 			goto err_out;
 	}
@@ -728,7 +730,8 @@ static int ext4_ind_truncate_ensure_credits(handle_t *handle,
 		return ret;
 	if (bh) {
 		BUFFER_TRACE(bh, "retaking write access");
-		ret = ext4_journal_get_write_access(handle, bh);
+		ret = ext4_journal_get_write_access(handle, inode->i_sb, bh,
+						    EXT4_JTR_NONE);
 		if (unlikely(ret))
 			return ret;
 	}
@@ -916,7 +919,8 @@ static void ext4_free_data(handle_t *handle, struct inode *inode,
 
 	if (this_bh) {				/* For indirect block */
 		BUFFER_TRACE(this_bh, "get_write_access");
-		err = ext4_journal_get_write_access(handle, this_bh);
+		err = ext4_journal_get_write_access(handle, inode->i_sb,
+						    this_bh, EXT4_JTR_NONE);
 		/* Important: if we can't update the indirect pointers
 		 * to the blocks, we can't free them. */
 		if (err)
@@ -1079,7 +1083,8 @@ static void ext4_free_branches(handle_t *handle, struct inode *inode,
 				 */
 				BUFFER_TRACE(parent_bh, "get_write_access");
 				if (!ext4_journal_get_write_access(handle,
-								   parent_bh)){
+						inode->i_sb, parent_bh,
+						EXT4_JTR_NONE)) {
 					*p = 0;
 					BUFFER_TRACE(parent_bh,
 					"call ext4_handle_dirty_metadata");
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index 70cb64db33f7..fc15ed79f09d 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -264,7 +264,8 @@ static int ext4_create_inline_data(handle_t *handle,
 		return error;
 
 	BUFFER_TRACE(is.iloc.bh, "get_write_access");
-	error = ext4_journal_get_write_access(handle, is.iloc.bh);
+	error = ext4_journal_get_write_access(handle, inode->i_sb, is.iloc.bh,
+					      EXT4_JTR_NONE);
 	if (error)
 		goto out;
 
@@ -350,7 +351,8 @@ static int ext4_update_inline_data(handle_t *handle, struct inode *inode,
 		goto out;
 
 	BUFFER_TRACE(is.iloc.bh, "get_write_access");
-	error = ext4_journal_get_write_access(handle, is.iloc.bh);
+	error = ext4_journal_get_write_access(handle, inode->i_sb, is.iloc.bh,
+					      EXT4_JTR_NONE);
 	if (error)
 		goto out;
 
@@ -427,7 +429,8 @@ static int ext4_destroy_inline_data_nolock(handle_t *handle,
 		goto out;
 
 	BUFFER_TRACE(is.iloc.bh, "get_write_access");
-	error = ext4_journal_get_write_access(handle, is.iloc.bh);
+	error = ext4_journal_get_write_access(handle, inode->i_sb, is.iloc.bh,
+					      EXT4_JTR_NONE);
 	if (error)
 		goto out;
 
@@ -593,7 +596,7 @@ static int ext4_convert_inline_data_to_extent(struct address_space *mapping,
 		ret = __block_write_begin(page, from, to, ext4_get_block);
 
 	if (!ret && ext4_should_journal_data(inode)) {
-		ret = ext4_walk_page_buffers(handle, page_buffers(page),
+		ret = ext4_walk_page_buffers(handle, inode, page_buffers(page),
 					     from, to, NULL,
 					     do_journal_get_write_access);
 	}
@@ -682,7 +685,8 @@ int ext4_try_to_write_inline_data(struct address_space *mapping,
 		goto convert;
 	}
 
-	ret = ext4_journal_get_write_access(handle, iloc.bh);
+	ret = ext4_journal_get_write_access(handle, inode->i_sb, iloc.bh,
+					    EXT4_JTR_NONE);
 	if (ret)
 		goto out;
 
@@ -923,7 +927,8 @@ int ext4_da_write_inline_data_begin(struct address_space *mapping,
 		if (ret < 0)
 			goto out_release_page;
 	}
-	ret = ext4_journal_get_write_access(handle, iloc.bh);
+	ret = ext4_journal_get_write_access(handle, inode->i_sb, iloc.bh,
+					    EXT4_JTR_NONE);
 	if (ret)
 		goto out_release_page;
 
@@ -1028,7 +1033,8 @@ static int ext4_add_dirent_to_inline(handle_t *handle,
 		return err;
 
 	BUFFER_TRACE(iloc->bh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, iloc->bh);
+	err = ext4_journal_get_write_access(handle, dir->i_sb, iloc->bh,
+					    EXT4_JTR_NONE);
 	if (err)
 		return err;
 	ext4_insert_dentry(dir, inode, de, inline_size, fname);
@@ -1223,7 +1229,8 @@ static int ext4_convert_inline_data_nolock(handle_t *handle,
 	}
 
 	lock_buffer(data_bh);
-	error = ext4_journal_get_create_access(handle, data_bh);
+	error = ext4_journal_get_create_access(handle, inode->i_sb, data_bh,
+					       EXT4_JTR_NONE);
 	if (error) {
 		unlock_buffer(data_bh);
 		error = -EIO;
@@ -1707,7 +1714,8 @@ int ext4_delete_inline_entry(handle_t *handle,
 	}
 
 	BUFFER_TRACE(bh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, bh);
+	err = ext4_journal_get_write_access(handle, dir->i_sb, bh,
+					    EXT4_JTR_NONE);
 	if (err)
 		goto out;
 
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index d8de607849df..d29bd3bfbcfd 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -139,7 +139,6 @@ static inline int ext4_begin_ordered_truncate(struct inode *inode,
 static void ext4_invalidatepage(struct page *page, unsigned int offset,
 				unsigned int length);
 static int __ext4_journalled_writepage(struct page *page, unsigned int len);
-static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh);
 static int ext4_meta_trans_blocks(struct inode *inode, int lblocks,
 				  int pextents);
 
@@ -869,7 +868,8 @@ struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
 		 */
 		lock_buffer(bh);
 		BUFFER_TRACE(bh, "call get_create_access");
-		err = ext4_journal_get_create_access(handle, bh);
+		err = ext4_journal_get_create_access(handle, inode->i_sb, bh,
+						     EXT4_JTR_NONE);
 		if (unlikely(err)) {
 			unlock_buffer(bh);
 			goto errout;
@@ -954,12 +954,12 @@ int ext4_bread_batch(struct inode *inode, ext4_lblk_t block, int bh_count,
 	return err;
 }
 
-int ext4_walk_page_buffers(handle_t *handle,
+int ext4_walk_page_buffers(handle_t *handle, struct inode *inode,
 			   struct buffer_head *head,
 			   unsigned from,
 			   unsigned to,
 			   int *partial,
-			   int (*fn)(handle_t *handle,
+			   int (*fn)(handle_t *handle, struct inode *inode,
 				     struct buffer_head *bh))
 {
 	struct buffer_head *bh;
@@ -978,7 +978,7 @@ int ext4_walk_page_buffers(handle_t *handle,
 				*partial = 1;
 			continue;
 		}
-		err = (*fn)(handle, bh);
+		err = (*fn)(handle, inode, bh);
 		if (!ret)
 			ret = err;
 	}
@@ -1009,7 +1009,7 @@ int ext4_walk_page_buffers(handle_t *handle,
  * is elevated.  We'll still have enough credits for the tiny quotafile
  * write.
  */
-int do_journal_get_write_access(handle_t *handle,
+int do_journal_get_write_access(handle_t *handle, struct inode *inode,
 				struct buffer_head *bh)
 {
 	int dirty = buffer_dirty(bh);
@@ -1028,7 +1028,8 @@ int do_journal_get_write_access(handle_t *handle,
 	if (dirty)
 		clear_buffer_dirty(bh);
 	BUFFER_TRACE(bh, "get write access");
-	ret = ext4_journal_get_write_access(handle, bh);
+	ret = ext4_journal_get_write_access(handle, inode->i_sb, bh,
+					    EXT4_JTR_NONE);
 	if (!ret && dirty)
 		ret = ext4_handle_dirty_metadata(handle, NULL, bh);
 	return ret;
@@ -1208,8 +1209,8 @@ static int ext4_write_begin(struct file *file, struct address_space *mapping,
 		ret = __block_write_begin(page, pos, len, ext4_get_block);
 #endif
 	if (!ret && ext4_should_journal_data(inode)) {
-		ret = ext4_walk_page_buffers(handle, page_buffers(page),
-					     from, to, NULL,
+		ret = ext4_walk_page_buffers(handle, inode,
+					     page_buffers(page), from, to, NULL,
 					     do_journal_get_write_access);
 	}
 
@@ -1253,7 +1254,8 @@ static int ext4_write_begin(struct file *file, struct address_space *mapping,
 }
 
 /* For write_end() in data=journal mode */
-static int write_end_fn(handle_t *handle, struct buffer_head *bh)
+static int write_end_fn(handle_t *handle, struct inode *inode,
+			struct buffer_head *bh)
 {
 	int ret;
 	if (!buffer_mapped(bh) || buffer_freed(bh))
@@ -1352,6 +1354,7 @@ static int ext4_write_end(struct file *file,
  * to call ext4_handle_dirty_metadata() instead.
  */
 static void ext4_journalled_zero_new_buffers(handle_t *handle,
+					    struct inode *inode,
 					    struct page *page,
 					    unsigned from, unsigned to)
 {
@@ -1370,7 +1373,7 @@ static void ext4_journalled_zero_new_buffers(handle_t *handle,
 					size = min(to, block_end) - start;
 
 					zero_user(page, start, size);
-					write_end_fn(handle, bh);
+					write_end_fn(handle, inode, bh);
 				}
 				clear_buffer_new(bh);
 			}
@@ -1412,13 +1415,13 @@ static int ext4_journalled_write_end(struct file *file,
 		copied = ret;
 	} else if (unlikely(copied < len) && !PageUptodate(page)) {
 		copied = 0;
-		ext4_journalled_zero_new_buffers(handle, page, from, to);
+		ext4_journalled_zero_new_buffers(handle, inode, page, from, to);
 	} else {
 		if (unlikely(copied < len))
-			ext4_journalled_zero_new_buffers(handle, page,
+			ext4_journalled_zero_new_buffers(handle, inode, page,
 							 from + copied, to);
-		ret = ext4_walk_page_buffers(handle, page_buffers(page), from,
-					     from + copied, &partial,
+		ret = ext4_walk_page_buffers(handle, inode, page_buffers(page),
+					     from, from + copied, &partial,
 					     write_end_fn);
 		if (!partial)
 			SetPageUptodate(page);
@@ -1619,7 +1622,8 @@ static void ext4_print_free_blocks(struct inode *inode)
 	return;
 }
 
-static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh)
+static int ext4_bh_delay_or_unwritten(handle_t *handle, struct inode *inode,
+				      struct buffer_head *bh)
 {
 	return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh);
 }
@@ -1851,13 +1855,15 @@ int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
 	return 0;
 }
 
-static int bget_one(handle_t *handle, struct buffer_head *bh)
+static int bget_one(handle_t *handle, struct inode *inode,
+		    struct buffer_head *bh)
 {
 	get_bh(bh);
 	return 0;
 }
 
-static int bput_one(handle_t *handle, struct buffer_head *bh)
+static int bput_one(handle_t *handle, struct inode *inode,
+		    struct buffer_head *bh)
 {
 	put_bh(bh);
 	return 0;
@@ -1888,7 +1894,7 @@ static int __ext4_journalled_writepage(struct page *page,
 			BUG();
 			goto out;
 		}
-		ext4_walk_page_buffers(handle, page_bufs, 0, len,
+		ext4_walk_page_buffers(handle, inode, page_bufs, 0, len,
 				       NULL, bget_one);
 	}
 	/*
@@ -1920,11 +1926,11 @@ static int __ext4_journalled_writepage(struct page *page,
 	if (inline_data) {
 		ret = ext4_mark_inode_dirty(handle, inode);
 	} else {
-		ret = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL,
-					     do_journal_get_write_access);
+		ret = ext4_walk_page_buffers(handle, inode, page_bufs, 0, len,
+					     NULL, do_journal_get_write_access);
 
-		err = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL,
-					     write_end_fn);
+		err = ext4_walk_page_buffers(handle, inode, page_bufs, 0, len,
+					     NULL, write_end_fn);
 	}
 	if (ret == 0)
 		ret = err;
@@ -1941,7 +1947,7 @@ static int __ext4_journalled_writepage(struct page *page,
 	unlock_page(page);
 out_no_pagelock:
 	if (!inline_data && page_bufs)
-		ext4_walk_page_buffers(NULL, page_bufs, 0, len,
+		ext4_walk_page_buffers(NULL, inode, page_bufs, 0, len,
 				       NULL, bput_one);
 	brelse(inode_bh);
 	return ret;
@@ -2031,7 +2037,7 @@ static int ext4_writepage(struct page *page,
 	 * for the extremely common case, this is an optimization that
 	 * skips a useless round trip through ext4_bio_write_page().
 	 */
-	if (ext4_walk_page_buffers(NULL, page_bufs, 0, len, NULL,
+	if (ext4_walk_page_buffers(NULL, inode, page_bufs, 0, len, NULL,
 				   ext4_bh_delay_or_unwritten)) {
 		redirty_page_for_writepage(wbc, page);
 		if ((current->flags & PF_MEMALLOC) ||
@@ -3794,7 +3800,8 @@ static int __ext4_block_zero_page_range(handle_t *handle,
 	}
 	if (ext4_should_journal_data(inode)) {
 		BUFFER_TRACE(bh, "get write access");
-		err = ext4_journal_get_write_access(handle, bh);
+		err = ext4_journal_get_write_access(handle, inode->i_sb, bh,
+						    EXT4_JTR_NONE);
 		if (err)
 			goto unlock;
 	}
@@ -5142,7 +5149,9 @@ static int ext4_do_update_inode(handle_t *handle,
 	ext4_clear_inode_state(inode, EXT4_STATE_NEW);
 	if (set_large_file) {
 		BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get write access");
-		err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
+		err = ext4_journal_get_write_access(handle, sb,
+						    EXT4_SB(sb)->s_sbh,
+						    EXT4_JTR_NONE);
 		if (err)
 			goto out_brelse;
 		lock_buffer(EXT4_SB(sb)->s_sbh);
@@ -5743,7 +5752,8 @@ ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
 	err = ext4_get_inode_loc(inode, iloc);
 	if (!err) {
 		BUFFER_TRACE(iloc->bh, "get_write_access");
-		err = ext4_journal_get_write_access(handle, iloc->bh);
+		err = ext4_journal_get_write_access(handle, inode->i_sb,
+						    iloc->bh, EXT4_JTR_NONE);
 		if (err) {
 			brelse(iloc->bh);
 			iloc->bh = NULL;
@@ -5866,7 +5876,8 @@ int ext4_expand_extra_isize(struct inode *inode,
 	ext4_write_lock_xattr(inode, &no_expand);
 
 	BUFFER_TRACE(iloc->bh, "get_write_access");
-	error = ext4_journal_get_write_access(handle, iloc->bh);
+	error = ext4_journal_get_write_access(handle, inode->i_sb, iloc->bh,
+					      EXT4_JTR_NONE);
 	if (error) {
 		brelse(iloc->bh);
 		goto out_unlock;
@@ -6037,7 +6048,8 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val)
 	return err;
 }
 
-static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
+static int ext4_bh_unmapped(handle_t *handle, struct inode *inode,
+			    struct buffer_head *bh)
 {
 	return !buffer_mapped(bh);
 }
@@ -6110,7 +6122,7 @@ vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf)
 	 * inode to the transaction's list to writeprotect pages on commit.
 	 */
 	if (page_has_buffers(page)) {
-		if (!ext4_walk_page_buffers(NULL, page_buffers(page),
+		if (!ext4_walk_page_buffers(NULL, inode, page_buffers(page),
 					    0, len, NULL,
 					    ext4_bh_unmapped)) {
 			/* Wait so that we don't change page under IO */
@@ -6156,11 +6168,13 @@ vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf)
 		err = __block_write_begin(page, 0, len, ext4_get_block);
 		if (!err) {
 			ret = VM_FAULT_SIGBUS;
-			if (ext4_walk_page_buffers(handle, page_buffers(page),
-					0, len, NULL, do_journal_get_write_access))
+			if (ext4_walk_page_buffers(handle, inode,
+					page_buffers(page), 0, len, NULL,
+					do_journal_get_write_access))
 				goto out_error;
-			if (ext4_walk_page_buffers(handle, page_buffers(page),
-					0, len, NULL, write_end_fn))
+			if (ext4_walk_page_buffers(handle, inode,
+					page_buffers(page), 0, len, NULL,
+					write_end_fn))
 				goto out_error;
 			if (ext4_jbd2_inode_add_write(handle, inode,
 						      page_offset(page), len))
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 6eed6170aded..20aeff88cab6 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -1154,7 +1154,9 @@ static long __ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 				err = PTR_ERR(handle);
 				goto pwsalt_err_exit;
 			}
-			err = ext4_journal_get_write_access(handle, sbi->s_sbh);
+			err = ext4_journal_get_write_access(handle, sb,
+							    sbi->s_sbh,
+							    EXT4_JTR_NONE);
 			if (err)
 				goto pwsalt_err_journal;
 			lock_buffer(sbi->s_sbh);
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 089c958aa2c3..349fabed7e0a 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -3726,7 +3726,8 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
 	}
 
 	BUFFER_TRACE(bitmap_bh, "getting write access");
-	err = ext4_journal_get_write_access(handle, bitmap_bh);
+	err = ext4_journal_get_write_access(handle, sb, bitmap_bh,
+					    EXT4_JTR_NONE);
 	if (err)
 		goto out_err;
 
@@ -3739,7 +3740,7 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
 			ext4_free_group_clusters(sb, gdp));
 
 	BUFFER_TRACE(gdp_bh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, gdp_bh);
+	err = ext4_journal_get_write_access(handle, sb, gdp_bh, EXT4_JTR_NONE);
 	if (err)
 		goto out_err;
 
@@ -5916,7 +5917,8 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode,
 	}
 
 	BUFFER_TRACE(bitmap_bh, "getting write access");
-	err = ext4_journal_get_write_access(handle, bitmap_bh);
+	err = ext4_journal_get_write_access(handle, sb, bitmap_bh,
+					    EXT4_JTR_NONE);
 	if (err)
 		goto error_return;
 
@@ -5926,7 +5928,7 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode,
 	 * using it
 	 */
 	BUFFER_TRACE(gd_bh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, gd_bh);
+	err = ext4_journal_get_write_access(handle, sb, gd_bh, EXT4_JTR_NONE);
 	if (err)
 		goto error_return;
 #ifdef AGGRESSIVE_CHECK
@@ -6107,7 +6109,8 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
 	}
 
 	BUFFER_TRACE(bitmap_bh, "getting write access");
-	err = ext4_journal_get_write_access(handle, bitmap_bh);
+	err = ext4_journal_get_write_access(handle, sb, bitmap_bh,
+					    EXT4_JTR_NONE);
 	if (err)
 		goto error_return;
 
@@ -6117,7 +6120,7 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
 	 * using it
 	 */
 	BUFFER_TRACE(gd_bh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, gd_bh);
+	err = ext4_journal_get_write_access(handle, sb, gd_bh, EXT4_JTR_NONE);
 	if (err)
 		goto error_return;
 
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index f3bbcd4efb56..dfb3ae61dfe8 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -70,7 +70,8 @@ static struct buffer_head *ext4_append(handle_t *handle,
 	inode->i_size += inode->i_sb->s_blocksize;
 	EXT4_I(inode)->i_disksize = inode->i_size;
 	BUFFER_TRACE(bh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, bh);
+	err = ext4_journal_get_write_access(handle, inode->i_sb, bh,
+					    EXT4_JTR_NONE);
 	if (err) {
 		brelse(bh);
 		ext4_std_error(inode->i_sb, err);
@@ -1927,12 +1928,14 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
 	}
 
 	BUFFER_TRACE(*bh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, *bh);
+	err = ext4_journal_get_write_access(handle, dir->i_sb, *bh,
+					    EXT4_JTR_NONE);
 	if (err)
 		goto journal_error;
 
 	BUFFER_TRACE(frame->bh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, frame->bh);
+	err = ext4_journal_get_write_access(handle, dir->i_sb, frame->bh,
+					    EXT4_JTR_NONE);
 	if (err)
 		goto journal_error;
 
@@ -2109,7 +2112,8 @@ static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
 			return err;
 	}
 	BUFFER_TRACE(bh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, bh);
+	err = ext4_journal_get_write_access(handle, dir->i_sb, bh,
+					    EXT4_JTR_NONE);
 	if (err) {
 		ext4_std_error(dir->i_sb, err);
 		return err;
@@ -2167,7 +2171,8 @@ static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
 	blocksize =  dir->i_sb->s_blocksize;
 	dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
 	BUFFER_TRACE(bh, "get_write_access");
-	retval = ext4_journal_get_write_access(handle, bh);
+	retval = ext4_journal_get_write_access(handle, dir->i_sb, bh,
+					       EXT4_JTR_NONE);
 	if (retval) {
 		ext4_std_error(dir->i_sb, retval);
 		brelse(bh);
@@ -2419,7 +2424,7 @@ static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
 	}
 
 	BUFFER_TRACE(bh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, bh);
+	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
 	if (err)
 		goto journal_error;
 
@@ -2476,7 +2481,8 @@ static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
 		node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
 							   sb->s_blocksize);
 		BUFFER_TRACE(frame->bh, "get_write_access");
-		err = ext4_journal_get_write_access(handle, frame->bh);
+		err = ext4_journal_get_write_access(handle, sb, frame->bh,
+						    EXT4_JTR_NONE);
 		if (err)
 			goto journal_error;
 		if (!add_level) {
@@ -2486,8 +2492,9 @@ static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
 				       icount1, icount2));
 
 			BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
-			err = ext4_journal_get_write_access(handle,
-							     (frame - 1)->bh);
+			err = ext4_journal_get_write_access(handle, sb,
+							    (frame - 1)->bh,
+							    EXT4_JTR_NONE);
 			if (err)
 				goto journal_error;
 
@@ -2636,7 +2643,8 @@ static int ext4_delete_entry(handle_t *handle,
 		csum_size = sizeof(struct ext4_dir_entry_tail);
 
 	BUFFER_TRACE(bh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, bh);
+	err = ext4_journal_get_write_access(handle, dir->i_sb, bh,
+					    EXT4_JTR_NONE);
 	if (unlikely(err))
 		goto out;
 
@@ -3088,7 +3096,8 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode)
 		  S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
 
 	BUFFER_TRACE(sbi->s_sbh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, sbi->s_sbh);
+	err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,
+					    EXT4_JTR_NONE);
 	if (err)
 		goto out;
 
@@ -3186,7 +3195,8 @@ int ext4_orphan_del(handle_t *handle, struct inode *inode)
 	if (prev == &sbi->s_orphan) {
 		jbd_debug(4, "superblock will point to %u\n", ino_next);
 		BUFFER_TRACE(sbi->s_sbh, "get_write_access");
-		err = ext4_journal_get_write_access(handle, sbi->s_sbh);
+		err = ext4_journal_get_write_access(handle, inode->i_sb,
+						    sbi->s_sbh, EXT4_JTR_NONE);
 		if (err) {
 			mutex_unlock(&sbi->s_orphan_lock);
 			goto out_brelse;
@@ -3675,7 +3685,8 @@ static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
 	if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
 		return -EFSCORRUPTED;
 	BUFFER_TRACE(ent->dir_bh, "get_write_access");
-	return ext4_journal_get_write_access(handle, ent->dir_bh);
+	return ext4_journal_get_write_access(handle, ent->dir->i_sb,
+					     ent->dir_bh, EXT4_JTR_NONE);
 }
 
 static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
@@ -3710,7 +3721,8 @@ static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
 	int retval, retval2;
 
 	BUFFER_TRACE(ent->bh, "get write access");
-	retval = ext4_journal_get_write_access(handle, ent->bh);
+	retval = ext4_journal_get_write_access(handle, ent->dir->i_sb, ent->bh,
+					       EXT4_JTR_NONE);
 	if (retval)
 		return retval;
 	ent->de->inode = cpu_to_le32(ino);
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 7a9f1adef679..b63cb88ccdae 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -409,7 +409,8 @@ static struct buffer_head *bclean(handle_t *handle, struct super_block *sb,
 	if (unlikely(!bh))
 		return ERR_PTR(-ENOMEM);
 	BUFFER_TRACE(bh, "get_write_access");
-	if ((err = ext4_journal_get_write_access(handle, bh))) {
+	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
+	if (err) {
 		brelse(bh);
 		bh = ERR_PTR(err);
 	} else {
@@ -474,7 +475,8 @@ static int set_flexbg_block_bitmap(struct super_block *sb, handle_t *handle,
 			return -ENOMEM;
 
 		BUFFER_TRACE(bh, "get_write_access");
-		err = ext4_journal_get_write_access(handle, bh);
+		err = ext4_journal_get_write_access(handle, sb, bh,
+						    EXT4_JTR_NONE);
 		if (err) {
 			brelse(bh);
 			return err;
@@ -569,7 +571,8 @@ static int setup_new_flex_group_blocks(struct super_block *sb,
 			}
 
 			BUFFER_TRACE(gdb, "get_write_access");
-			err = ext4_journal_get_write_access(handle, gdb);
+			err = ext4_journal_get_write_access(handle, sb, gdb,
+							    EXT4_JTR_NONE);
 			if (err) {
 				brelse(gdb);
 				goto out;
@@ -837,17 +840,18 @@ static int add_new_gdb(handle_t *handle, struct inode *inode,
 	}
 
 	BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
+	err = ext4_journal_get_write_access(handle, sb, EXT4_SB(sb)->s_sbh,
+					    EXT4_JTR_NONE);
 	if (unlikely(err))
 		goto errout;
 
 	BUFFER_TRACE(gdb_bh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, gdb_bh);
+	err = ext4_journal_get_write_access(handle, sb, gdb_bh, EXT4_JTR_NONE);
 	if (unlikely(err))
 		goto errout;
 
 	BUFFER_TRACE(dind, "get_write_access");
-	err = ext4_journal_get_write_access(handle, dind);
+	err = ext4_journal_get_write_access(handle, sb, dind, EXT4_JTR_NONE);
 	if (unlikely(err)) {
 		ext4_std_error(sb, err);
 		goto errout;
@@ -956,7 +960,7 @@ static int add_new_gdb_meta_bg(struct super_block *sb,
 	n_group_desc[gdb_num] = gdb_bh;
 
 	BUFFER_TRACE(gdb_bh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, gdb_bh);
+	err = ext4_journal_get_write_access(handle, sb, gdb_bh, EXT4_JTR_NONE);
 	if (err) {
 		kvfree(n_group_desc);
 		brelse(gdb_bh);
@@ -1042,7 +1046,8 @@ static int reserve_backup_gdb(handle_t *handle, struct inode *inode,
 
 	for (i = 0; i < reserved_gdb; i++) {
 		BUFFER_TRACE(primary[i], "get_write_access");
-		if ((err = ext4_journal_get_write_access(handle, primary[i])))
+		if ((err = ext4_journal_get_write_access(handle, sb, primary[i],
+							 EXT4_JTR_NONE)))
 			goto exit_bh;
 	}
 
@@ -1149,10 +1154,9 @@ static void update_backups(struct super_block *sb, sector_t blk_off, char *data,
 			   backup_block, backup_block -
 			   ext4_group_first_block_no(sb, group));
 		BUFFER_TRACE(bh, "get_write_access");
-		if ((err = ext4_journal_get_write_access(handle, bh))) {
-			brelse(bh);
+		if ((err = ext4_journal_get_write_access(handle, sb, bh,
+							 EXT4_JTR_NONE)))
 			break;
-		}
 		lock_buffer(bh);
 		memcpy(bh->b_data, data, size);
 		if (rest)
@@ -1232,7 +1236,8 @@ static int ext4_add_new_descs(handle_t *handle, struct super_block *sb,
 			gdb_bh = sbi_array_rcu_deref(sbi, s_group_desc,
 						     gdb_num);
 			BUFFER_TRACE(gdb_bh, "get_write_access");
-			err = ext4_journal_get_write_access(handle, gdb_bh);
+			err = ext4_journal_get_write_access(handle, sb, gdb_bh,
+							    EXT4_JTR_NONE);
 
 			if (!err && reserved_gdb && ext4_bg_num_gdb(sb, group))
 				err = reserve_backup_gdb(handle, resize_inode, group);
@@ -1509,7 +1514,8 @@ static int ext4_flex_group_add(struct super_block *sb,
 	}
 
 	BUFFER_TRACE(sbi->s_sbh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, sbi->s_sbh);
+	err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,
+					    EXT4_JTR_NONE);
 	if (err)
 		goto exit_journal;
 
@@ -1722,7 +1728,8 @@ static int ext4_group_extend_no_check(struct super_block *sb,
 	}
 
 	BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
+	err = ext4_journal_get_write_access(handle, sb, EXT4_SB(sb)->s_sbh,
+					    EXT4_JTR_NONE);
 	if (err) {
 		ext4_warning(sb, "error %d on journal write access", err);
 		goto errout;
@@ -1884,7 +1891,8 @@ static int ext4_convert_meta_bg(struct super_block *sb, struct inode *inode)
 		return PTR_ERR(handle);
 
 	BUFFER_TRACE(sbi->s_sbh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, sbi->s_sbh);
+	err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,
+					    EXT4_JTR_NONE);
 	if (err)
 		goto errout;
 
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index dfa09a277b56..61fcea9dce3d 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4014,6 +4014,20 @@ static const char *ext4_quota_mode(struct super_block *sb)
 #endif
 }
 
+static void ext4_setup_csum_trigger(struct super_block *sb,
+				    enum ext4_journal_trigger_type type,
+				    void (*trigger)(
+					struct jbd2_buffer_trigger_type *type,
+					struct buffer_head *bh,
+					void *mapped_data,
+					size_t size))
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	sbi->s_journal_triggers[type].sb = sb;
+	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
+}
+
 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 {
 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
@@ -6609,7 +6623,7 @@ static ssize_t ext4_quota_write(struct super_block *sb, int type,
 	if (!bh)
 		goto out;
 	BUFFER_TRACE(bh, "get write access");
-	err = ext4_journal_get_write_access(handle, bh);
+	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
 	if (err) {
 		brelse(bh);
 		return err;
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 6dd5c05c444a..1e0fc1ed845b 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -791,7 +791,8 @@ static void ext4_xattr_update_super_block(handle_t *handle,
 		return;
 
 	BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
-	if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) {
+	if (ext4_journal_get_write_access(handle, sb, EXT4_SB(sb)->s_sbh,
+					  EXT4_JTR_NONE) == 0) {
 		lock_buffer(EXT4_SB(sb)->s_sbh);
 		ext4_set_feature_xattr(sb);
 		ext4_superblock_csum_set(sb);
@@ -1169,7 +1170,8 @@ ext4_xattr_inode_dec_ref_all(handle_t *handle, struct inode *parent,
 			continue;
 		}
 		if (err > 0) {
-			err = ext4_journal_get_write_access(handle, bh);
+			err = ext4_journal_get_write_access(handle,
+					parent->i_sb, bh, EXT4_JTR_NONE);
 			if (err) {
 				ext4_warning_inode(ea_inode,
 						"Re-get write access err=%d",
@@ -1230,7 +1232,8 @@ ext4_xattr_release_block(handle_t *handle, struct inode *inode,
 	int error = 0;
 
 	BUFFER_TRACE(bh, "get_write_access");
-	error = ext4_journal_get_write_access(handle, bh);
+	error = ext4_journal_get_write_access(handle, inode->i_sb, bh,
+					      EXT4_JTR_NONE);
 	if (error)
 		goto out;
 
@@ -1371,7 +1374,8 @@ static int ext4_xattr_inode_write(handle_t *handle, struct inode *ea_inode,
 					 "ext4_getblk() return bh = NULL");
 			return -EFSCORRUPTED;
 		}
-		ret = ext4_journal_get_write_access(handle, bh);
+		ret = ext4_journal_get_write_access(handle, ea_inode->i_sb, bh,
+						   EXT4_JTR_NONE);
 		if (ret)
 			goto out;
 
@@ -1855,7 +1859,8 @@ ext4_xattr_block_set(handle_t *handle, struct inode *inode,
 
 	if (s->base) {
 		BUFFER_TRACE(bs->bh, "get_write_access");
-		error = ext4_journal_get_write_access(handle, bs->bh);
+		error = ext4_journal_get_write_access(handle, sb, bs->bh,
+						      EXT4_JTR_NONE);
 		if (error)
 			goto cleanup;
 		lock_buffer(bs->bh);
@@ -1987,8 +1992,9 @@ ext4_xattr_block_set(handle_t *handle, struct inode *inode,
 				if (error)
 					goto cleanup;
 				BUFFER_TRACE(new_bh, "get_write_access");
-				error = ext4_journal_get_write_access(handle,
-								      new_bh);
+				error = ext4_journal_get_write_access(
+						handle, sb, new_bh,
+						EXT4_JTR_NONE);
 				if (error)
 					goto cleanup_dquot;
 				lock_buffer(new_bh);
@@ -2092,7 +2098,8 @@ ext4_xattr_block_set(handle_t *handle, struct inode *inode,
 			}
 
 			lock_buffer(new_bh);
-			error = ext4_journal_get_create_access(handle, new_bh);
+			error = ext4_journal_get_create_access(handle, sb,
+							new_bh, EXT4_JTR_NONE);
 			if (error) {
 				unlock_buffer(new_bh);
 				error = -EIO;
@@ -2848,7 +2855,8 @@ int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode,
 			goto cleanup;
 		}
 
-		error = ext4_journal_get_write_access(handle, iloc.bh);
+		error = ext4_journal_get_write_access(handle, inode->i_sb,
+						iloc.bh, EXT4_JTR_NONE);
 		if (error) {
 			EXT4_ERROR_INODE(inode, "write access (error %d)",
 					 error);
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 8804e126805f..707f92d78c69 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -1404,7 +1404,7 @@ void jbd2_journal_set_triggers(struct buffer_head *bh,
 {
 	struct journal_head *jh = jbd2_journal_grab_journal_head(bh);
 
-	if (WARN_ON(!jh))
+	if (WARN_ON_ONCE(!jh))
 		return;
 	jh->b_triggers = type;
 	jbd2_journal_put_journal_head(jh);
-- 
2.26.2

[PATCH 2/5] ext4: Move orphan inode handling into a separate file

[Jan Kara]

Move functions for handling orphan inodes into a new file
fs/ext4/orphan.c to have them in one place and somewhat reduce size of
other files. No code changes.

Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/ext4/Makefile |   2 +-
 fs/ext4/ext4.h   |  11 +-
 fs/ext4/namei.c  | 182 ------------------------
 fs/ext4/orphan.c | 363 +++++++++++++++++++++++++++++++++++++++++++++++
 fs/ext4/super.c  | 180 +----------------------
 5 files changed, 375 insertions(+), 363 deletions(-)
 create mode 100644 fs/ext4/orphan.c

diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile
index 49e7af6cc93f..7d89142e1421 100644
--- a/fs/ext4/Makefile
+++ b/fs/ext4/Makefile
@@ -10,7 +10,7 @@ ext4-y	:= balloc.o bitmap.o block_validity.o dir.o ext4_jbd2.o extents.o \
 		indirect.o inline.o inode.o ioctl.o mballoc.o migrate.o \
 		mmp.o move_extent.o namei.o page-io.o readpage.o resize.o \
 		super.o symlink.o sysfs.o xattr.o xattr_hurd.o xattr_trusted.o \
-		xattr_user.o fast_commit.o
+		xattr_user.o fast_commit.o orphan.o
 
 ext4-$(CONFIG_EXT4_FS_POSIX_ACL)	+= acl.o
 ext4-$(CONFIG_EXT4_FS_SECURITY)		+= xattr_security.o
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index c3cd7faa6cf2..b8194ea85fff 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2168,6 +2168,8 @@ static inline bool ext4_has_incompat_features(struct super_block *sb)
 	return (EXT4_SB(sb)->s_es->s_feature_incompat != 0);
 }
 
+extern int ext4_feature_set_ok(struct super_block *sb, int readonly);
+
 /*
  * Superblock flags
  */
@@ -3028,8 +3030,6 @@ extern int ext4_init_new_dir(handle_t *handle, struct inode *dir,
 			     struct inode *inode);
 extern int ext4_dirblock_csum_verify(struct inode *inode,
 				     struct buffer_head *bh);
-extern int ext4_orphan_add(handle_t *, struct inode *);
-extern int ext4_orphan_del(handle_t *, struct inode *);
 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
 				__u32 start_minor_hash, __u32 *next_hash);
 extern int ext4_search_dir(struct buffer_head *bh,
@@ -3498,6 +3498,7 @@ static inline bool ext4_is_quota_journalled(struct super_block *sb)
 	return (ext4_has_feature_quota(sb) ||
 		sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]);
 }
+int ext4_enable_quotas(struct super_block *sb);
 #endif
 
 /*
@@ -3759,6 +3760,12 @@ extern void ext4_stop_mmpd(struct ext4_sb_info *sbi);
 /* verity.c */
 extern const struct fsverity_operations ext4_verityops;
 
+/* orphan.c */
+extern int ext4_orphan_add(handle_t *, struct inode *);
+extern int ext4_orphan_del(handle_t *, struct inode *);
+extern void ext4_orphan_cleanup(struct super_block *sb,
+				struct ext4_super_block *es);
+
 /*
  * Add new method to test whether block and inode bitmaps are properly
  * initialized. With uninit_bg reading the block from disk is not enough
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index dfb3ae61dfe8..da7698341d7d 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -3054,188 +3054,6 @@ bool ext4_empty_dir(struct inode *inode)
 	return true;
 }
 
-/*
- * ext4_orphan_add() links an unlinked or truncated inode into a list of
- * such inodes, starting at the superblock, in case we crash before the
- * file is closed/deleted, or in case the inode truncate spans multiple
- * transactions and the last transaction is not recovered after a crash.
- *
- * At filesystem recovery time, we walk this list deleting unlinked
- * inodes and truncating linked inodes in ext4_orphan_cleanup().
- *
- * Orphan list manipulation functions must be called under i_mutex unless
- * we are just creating the inode or deleting it.
- */
-int ext4_orphan_add(handle_t *handle, struct inode *inode)
-{
-	struct super_block *sb = inode->i_sb;
-	struct ext4_sb_info *sbi = EXT4_SB(sb);
-	struct ext4_iloc iloc;
-	int err = 0, rc;
-	bool dirty = false;
-
-	if (!sbi->s_journal || is_bad_inode(inode))
-		return 0;
-
-	WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
-		     !inode_is_locked(inode));
-	/*
-	 * Exit early if inode already is on orphan list. This is a big speedup
-	 * since we don't have to contend on the global s_orphan_lock.
-	 */
-	if (!list_empty(&EXT4_I(inode)->i_orphan))
-		return 0;
-
-	/*
-	 * Orphan handling is only valid for files with data blocks
-	 * being truncated, or files being unlinked. Note that we either
-	 * hold i_mutex, or the inode can not be referenced from outside,
-	 * so i_nlink should not be bumped due to race
-	 */
-	ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
-		  S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
-
-	BUFFER_TRACE(sbi->s_sbh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,
-					    EXT4_JTR_NONE);
-	if (err)
-		goto out;
-
-	err = ext4_reserve_inode_write(handle, inode, &iloc);
-	if (err)
-		goto out;
-
-	mutex_lock(&sbi->s_orphan_lock);
-	/*
-	 * Due to previous errors inode may be already a part of on-disk
-	 * orphan list. If so skip on-disk list modification.
-	 */
-	if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
-	    (le32_to_cpu(sbi->s_es->s_inodes_count))) {
-		/* Insert this inode at the head of the on-disk orphan list */
-		NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
-		lock_buffer(sbi->s_sbh);
-		sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
-		ext4_superblock_csum_set(sb);
-		unlock_buffer(sbi->s_sbh);
-		dirty = true;
-	}
-	list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
-	mutex_unlock(&sbi->s_orphan_lock);
-
-	if (dirty) {
-		err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
-		rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
-		if (!err)
-			err = rc;
-		if (err) {
-			/*
-			 * We have to remove inode from in-memory list if
-			 * addition to on disk orphan list failed. Stray orphan
-			 * list entries can cause panics at unmount time.
-			 */
-			mutex_lock(&sbi->s_orphan_lock);
-			list_del_init(&EXT4_I(inode)->i_orphan);
-			mutex_unlock(&sbi->s_orphan_lock);
-		}
-	} else
-		brelse(iloc.bh);
-
-	jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
-	jbd_debug(4, "orphan inode %lu will point to %d\n",
-			inode->i_ino, NEXT_ORPHAN(inode));
-out:
-	ext4_std_error(sb, err);
-	return err;
-}
-
-/*
- * ext4_orphan_del() removes an unlinked or truncated inode from the list
- * of such inodes stored on disk, because it is finally being cleaned up.
- */
-int ext4_orphan_del(handle_t *handle, struct inode *inode)
-{
-	struct list_head *prev;
-	struct ext4_inode_info *ei = EXT4_I(inode);
-	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
-	__u32 ino_next;
-	struct ext4_iloc iloc;
-	int err = 0;
-
-	if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
-		return 0;
-
-	WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
-		     !inode_is_locked(inode));
-	/* Do this quick check before taking global s_orphan_lock. */
-	if (list_empty(&ei->i_orphan))
-		return 0;
-
-	if (handle) {
-		/* Grab inode buffer early before taking global s_orphan_lock */
-		err = ext4_reserve_inode_write(handle, inode, &iloc);
-	}
-
-	mutex_lock(&sbi->s_orphan_lock);
-	jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
-
-	prev = ei->i_orphan.prev;
-	list_del_init(&ei->i_orphan);
-
-	/* If we're on an error path, we may not have a valid
-	 * transaction handle with which to update the orphan list on
-	 * disk, but we still need to remove the inode from the linked
-	 * list in memory. */
-	if (!handle || err) {
-		mutex_unlock(&sbi->s_orphan_lock);
-		goto out_err;
-	}
-
-	ino_next = NEXT_ORPHAN(inode);
-	if (prev == &sbi->s_orphan) {
-		jbd_debug(4, "superblock will point to %u\n", ino_next);
-		BUFFER_TRACE(sbi->s_sbh, "get_write_access");
-		err = ext4_journal_get_write_access(handle, inode->i_sb,
-						    sbi->s_sbh, EXT4_JTR_NONE);
-		if (err) {
-			mutex_unlock(&sbi->s_orphan_lock);
-			goto out_brelse;
-		}
-		lock_buffer(sbi->s_sbh);
-		sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
-		ext4_superblock_csum_set(inode->i_sb);
-		unlock_buffer(sbi->s_sbh);
-		mutex_unlock(&sbi->s_orphan_lock);
-		err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
-	} else {
-		struct ext4_iloc iloc2;
-		struct inode *i_prev =
-			&list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
-
-		jbd_debug(4, "orphan inode %lu will point to %u\n",
-			  i_prev->i_ino, ino_next);
-		err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
-		if (err) {
-			mutex_unlock(&sbi->s_orphan_lock);
-			goto out_brelse;
-		}
-		NEXT_ORPHAN(i_prev) = ino_next;
-		err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
-		mutex_unlock(&sbi->s_orphan_lock);
-	}
-	if (err)
-		goto out_brelse;
-	NEXT_ORPHAN(inode) = 0;
-	err = ext4_mark_iloc_dirty(handle, inode, &iloc);
-out_err:
-	ext4_std_error(inode->i_sb, err);
-	return err;
-
-out_brelse:
-	brelse(iloc.bh);
-	goto out_err;
-}
-
 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
 {
 	int retval;
diff --git a/fs/ext4/orphan.c b/fs/ext4/orphan.c
new file mode 100644
index 000000000000..1f2fa2ef53bd
--- /dev/null
+++ b/fs/ext4/orphan.c
@@ -0,0 +1,363 @@
+/*
+ * Ext4 orphan inode handling
+ */
+#include <linux/fs.h>
+#include <linux/quotaops.h>
+#include <linux/buffer_head.h>
+
+#include "ext4.h"
+#include "ext4_jbd2.h"
+
+/*
+ * ext4_orphan_add() links an unlinked or truncated inode into a list of
+ * such inodes, starting at the superblock, in case we crash before the
+ * file is closed/deleted, or in case the inode truncate spans multiple
+ * transactions and the last transaction is not recovered after a crash.
+ *
+ * At filesystem recovery time, we walk this list deleting unlinked
+ * inodes and truncating linked inodes in ext4_orphan_cleanup().
+ *
+ * Orphan list manipulation functions must be called under i_mutex unless
+ * we are just creating the inode or deleting it.
+ */
+int ext4_orphan_add(handle_t *handle, struct inode *inode)
+{
+	struct super_block *sb = inode->i_sb;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct ext4_iloc iloc;
+	int err = 0, rc;
+	bool dirty = false;
+
+	if (!sbi->s_journal || is_bad_inode(inode))
+		return 0;
+
+	WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
+		     !inode_is_locked(inode));
+	/*
+	 * Exit early if inode already is on orphan list. This is a big speedup
+	 * since we don't have to contend on the global s_orphan_lock.
+	 */
+	if (!list_empty(&EXT4_I(inode)->i_orphan))
+		return 0;
+
+	/*
+	 * Orphan handling is only valid for files with data blocks
+	 * being truncated, or files being unlinked. Note that we either
+	 * hold i_mutex, or the inode can not be referenced from outside,
+	 * so i_nlink should not be bumped due to race
+	 */
+	ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+		  S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
+
+	BUFFER_TRACE(sbi->s_sbh, "get_write_access");
+	err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,
+					    EXT4_JTR_NONE);
+	if (err)
+		goto out;
+
+	err = ext4_reserve_inode_write(handle, inode, &iloc);
+	if (err)
+		goto out;
+
+	mutex_lock(&sbi->s_orphan_lock);
+	/*
+	 * Due to previous errors inode may be already a part of on-disk
+	 * orphan list. If so skip on-disk list modification.
+	 */
+	if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
+	    (le32_to_cpu(sbi->s_es->s_inodes_count))) {
+		/* Insert this inode at the head of the on-disk orphan list */
+		NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
+		lock_buffer(sbi->s_sbh);
+		sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
+		ext4_superblock_csum_set(sb);
+		unlock_buffer(sbi->s_sbh);
+		dirty = true;
+	}
+	list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
+	mutex_unlock(&sbi->s_orphan_lock);
+
+	if (dirty) {
+		err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
+		rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
+		if (!err)
+			err = rc;
+		if (err) {
+			/*
+			 * We have to remove inode from in-memory list if
+			 * addition to on disk orphan list failed. Stray orphan
+			 * list entries can cause panics at unmount time.
+			 */
+			mutex_lock(&sbi->s_orphan_lock);
+			list_del_init(&EXT4_I(inode)->i_orphan);
+			mutex_unlock(&sbi->s_orphan_lock);
+		}
+	} else
+		brelse(iloc.bh);
+
+	jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
+	jbd_debug(4, "orphan inode %lu will point to %d\n",
+			inode->i_ino, NEXT_ORPHAN(inode));
+out:
+	ext4_std_error(sb, err);
+	return err;
+}
+
+/*
+ * ext4_orphan_del() removes an unlinked or truncated inode from the list
+ * of such inodes stored on disk, because it is finally being cleaned up.
+ */
+int ext4_orphan_del(handle_t *handle, struct inode *inode)
+{
+	struct list_head *prev;
+	struct ext4_inode_info *ei = EXT4_I(inode);
+	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+	__u32 ino_next;
+	struct ext4_iloc iloc;
+	int err = 0;
+
+	if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
+		return 0;
+
+	WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
+		     !inode_is_locked(inode));
+	/* Do this quick check before taking global s_orphan_lock. */
+	if (list_empty(&ei->i_orphan))
+		return 0;
+
+	if (handle) {
+		/* Grab inode buffer early before taking global s_orphan_lock */
+		err = ext4_reserve_inode_write(handle, inode, &iloc);
+	}
+
+	mutex_lock(&sbi->s_orphan_lock);
+	jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
+
+	prev = ei->i_orphan.prev;
+	list_del_init(&ei->i_orphan);
+
+	/* If we're on an error path, we may not have a valid
+	 * transaction handle with which to update the orphan list on
+	 * disk, but we still need to remove the inode from the linked
+	 * list in memory. */
+	if (!handle || err) {
+		mutex_unlock(&sbi->s_orphan_lock);
+		goto out_err;
+	}
+
+	ino_next = NEXT_ORPHAN(inode);
+	if (prev == &sbi->s_orphan) {
+		jbd_debug(4, "superblock will point to %u\n", ino_next);
+		BUFFER_TRACE(sbi->s_sbh, "get_write_access");
+		err = ext4_journal_get_write_access(handle, inode->i_sb,
+						    sbi->s_sbh, EXT4_JTR_NONE);
+		if (err) {
+			mutex_unlock(&sbi->s_orphan_lock);
+			goto out_brelse;
+		}
+		lock_buffer(sbi->s_sbh);
+		sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
+		ext4_superblock_csum_set(inode->i_sb);
+		unlock_buffer(sbi->s_sbh);
+		mutex_unlock(&sbi->s_orphan_lock);
+		err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
+	} else {
+		struct ext4_iloc iloc2;
+		struct inode *i_prev =
+			&list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
+
+		jbd_debug(4, "orphan inode %lu will point to %u\n",
+			  i_prev->i_ino, ino_next);
+		err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
+		if (err) {
+			mutex_unlock(&sbi->s_orphan_lock);
+			goto out_brelse;
+		}
+		NEXT_ORPHAN(i_prev) = ino_next;
+		err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
+		mutex_unlock(&sbi->s_orphan_lock);
+	}
+	if (err)
+		goto out_brelse;
+	NEXT_ORPHAN(inode) = 0;
+	err = ext4_mark_iloc_dirty(handle, inode, &iloc);
+out_err:
+	ext4_std_error(inode->i_sb, err);
+	return err;
+
+out_brelse:
+	brelse(iloc.bh);
+	goto out_err;
+}
+
+#ifdef CONFIG_QUOTA
+static int ext4_quota_on_mount(struct super_block *sb, int type)
+{
+	return dquot_quota_on_mount(sb,
+		rcu_dereference_protected(EXT4_SB(sb)->s_qf_names[type],
+					  lockdep_is_held(&sb->s_umount)),
+		EXT4_SB(sb)->s_jquota_fmt, type);
+}
+#endif
+
+/* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
+ * the superblock) which were deleted from all directories, but held open by
+ * a process at the time of a crash.  We walk the list and try to delete these
+ * inodes at recovery time (only with a read-write filesystem).
+ *
+ * In order to keep the orphan inode chain consistent during traversal (in
+ * case of crash during recovery), we link each inode into the superblock
+ * orphan list_head and handle it the same way as an inode deletion during
+ * normal operation (which journals the operations for us).
+ *
+ * We only do an iget() and an iput() on each inode, which is very safe if we
+ * accidentally point at an in-use or already deleted inode.  The worst that
+ * can happen in this case is that we get a "bit already cleared" message from
+ * ext4_free_inode().  The only reason we would point at a wrong inode is if
+ * e2fsck was run on this filesystem, and it must have already done the orphan
+ * inode cleanup for us, so we can safely abort without any further action.
+ */
+void ext4_orphan_cleanup(struct super_block *sb, struct ext4_super_block *es)
+{
+	unsigned int s_flags = sb->s_flags;
+	int ret, nr_orphans = 0, nr_truncates = 0;
+#ifdef CONFIG_QUOTA
+	int quota_update = 0;
+	int i;
+#endif
+	if (!es->s_last_orphan) {
+		jbd_debug(4, "no orphan inodes to clean up\n");
+		return;
+	}
+
+	if (bdev_read_only(sb->s_bdev)) {
+		ext4_msg(sb, KERN_ERR, "write access "
+			"unavailable, skipping orphan cleanup");
+		return;
+	}
+
+	/* Check if feature set would not allow a r/w mount */
+	if (!ext4_feature_set_ok(sb, 0)) {
+		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
+			 "unknown ROCOMPAT features");
+		return;
+	}
+
+	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
+		/* don't clear list on RO mount w/ errors */
+		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
+			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
+				  "clearing orphan list.\n");
+			es->s_last_orphan = 0;
+		}
+		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
+		return;
+	}
+
+	if (s_flags & SB_RDONLY) {
+		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
+		sb->s_flags &= ~SB_RDONLY;
+	}
+#ifdef CONFIG_QUOTA
+	/*
+	 * Turn on quotas which were not enabled for read-only mounts if
+	 * filesystem has quota feature, so that they are updated correctly.
+	 */
+	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
+		int ret = ext4_enable_quotas(sb);
+
+		if (!ret)
+			quota_update = 1;
+		else
+			ext4_msg(sb, KERN_ERR,
+				"Cannot turn on quotas: error %d", ret);
+	}
+
+	/* Turn on journaled quotas used for old sytle */
+	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
+		if (EXT4_SB(sb)->s_qf_names[i]) {
+			int ret = ext4_quota_on_mount(sb, i);
+
+			if (!ret)
+				quota_update = 1;
+			else
+				ext4_msg(sb, KERN_ERR,
+					"Cannot turn on journaled "
+					"quota: type %d: error %d", i, ret);
+		}
+	}
+#endif
+
+	while (es->s_last_orphan) {
+		struct inode *inode;
+
+		/*
+		 * We may have encountered an error during cleanup; if
+		 * so, skip the rest.
+		 */
+		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
+			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
+			es->s_last_orphan = 0;
+			break;
+		}
+
+		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
+		if (IS_ERR(inode)) {
+			es->s_last_orphan = 0;
+			break;
+		}
+
+		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
+		dquot_initialize(inode);
+		if (inode->i_nlink) {
+			if (test_opt(sb, DEBUG))
+				ext4_msg(sb, KERN_DEBUG,
+					"%s: truncating inode %lu to %lld bytes",
+					__func__, inode->i_ino, inode->i_size);
+			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
+				  inode->i_ino, inode->i_size);
+			inode_lock(inode);
+			truncate_inode_pages(inode->i_mapping, inode->i_size);
+			ret = ext4_truncate(inode);
+			if (ret) {
+				/*
+				 * We need to clean up the in-core orphan list
+				 * manually if ext4_truncate() failed to get a
+				 * transaction handle.
+				 */
+				ext4_orphan_del(NULL, inode);
+				ext4_std_error(inode->i_sb, ret);
+			}
+			inode_unlock(inode);
+			nr_truncates++;
+		} else {
+			if (test_opt(sb, DEBUG))
+				ext4_msg(sb, KERN_DEBUG,
+					"%s: deleting unreferenced inode %lu",
+					__func__, inode->i_ino);
+			jbd_debug(2, "deleting unreferenced inode %lu\n",
+				  inode->i_ino);
+			nr_orphans++;
+		}
+		iput(inode);  /* The delete magic happens here! */
+	}
+
+#define PLURAL(x) (x), ((x) == 1) ? "" : "s"
+
+	if (nr_orphans)
+		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
+		       PLURAL(nr_orphans));
+	if (nr_truncates)
+		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
+		       PLURAL(nr_truncates));
+#ifdef CONFIG_QUOTA
+	/* Turn off quotas if they were enabled for orphan cleanup */
+	if (quota_update) {
+		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
+			if (sb_dqopt(sb)->files[i])
+				dquot_quota_off(sb, i);
+		}
+	}
+#endif
+	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
+}
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 61fcea9dce3d..a7081d525faa 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -80,7 +80,6 @@ static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
 		       const char *dev_name, void *data);
 static inline int ext2_feature_set_ok(struct super_block *sb);
 static inline int ext3_feature_set_ok(struct super_block *sb);
-static int ext4_feature_set_ok(struct super_block *sb, int readonly);
 static void ext4_destroy_lazyinit_thread(void);
 static void ext4_unregister_li_request(struct super_block *sb);
 static void ext4_clear_request_list(void);
@@ -1585,14 +1584,12 @@ static int ext4_mark_dquot_dirty(struct dquot *dquot);
 static int ext4_write_info(struct super_block *sb, int type);
 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
 			 const struct path *path);
-static int ext4_quota_on_mount(struct super_block *sb, int type);
 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
 			       size_t len, loff_t off);
 static ssize_t ext4_quota_write(struct super_block *sb, int type,
 				const char *data, size_t len, loff_t off);
 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
 			     unsigned int flags);
-static int ext4_enable_quotas(struct super_block *sb);
 
 static struct dquot **ext4_get_dquots(struct inode *inode)
 {
@@ -2970,169 +2967,6 @@ static int ext4_check_descriptors(struct super_block *sb,
 	return 1;
 }
 
-/* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
- * the superblock) which were deleted from all directories, but held open by
- * a process at the time of a crash.  We walk the list and try to delete these
- * inodes at recovery time (only with a read-write filesystem).
- *
- * In order to keep the orphan inode chain consistent during traversal (in
- * case of crash during recovery), we link each inode into the superblock
- * orphan list_head and handle it the same way as an inode deletion during
- * normal operation (which journals the operations for us).
- *
- * We only do an iget() and an iput() on each inode, which is very safe if we
- * accidentally point at an in-use or already deleted inode.  The worst that
- * can happen in this case is that we get a "bit already cleared" message from
- * ext4_free_inode().  The only reason we would point at a wrong inode is if
- * e2fsck was run on this filesystem, and it must have already done the orphan
- * inode cleanup for us, so we can safely abort without any further action.
- */
-static void ext4_orphan_cleanup(struct super_block *sb,
-				struct ext4_super_block *es)
-{
-	unsigned int s_flags = sb->s_flags;
-	int ret, nr_orphans = 0, nr_truncates = 0;
-#ifdef CONFIG_QUOTA
-	int quota_update = 0;
-	int i;
-#endif
-	if (!es->s_last_orphan) {
-		jbd_debug(4, "no orphan inodes to clean up\n");
-		return;
-	}
-
-	if (bdev_read_only(sb->s_bdev)) {
-		ext4_msg(sb, KERN_ERR, "write access "
-			"unavailable, skipping orphan cleanup");
-		return;
-	}
-
-	/* Check if feature set would not allow a r/w mount */
-	if (!ext4_feature_set_ok(sb, 0)) {
-		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
-			 "unknown ROCOMPAT features");
-		return;
-	}
-
-	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
-		/* don't clear list on RO mount w/ errors */
-		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
-			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
-				  "clearing orphan list.\n");
-			es->s_last_orphan = 0;
-		}
-		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
-		return;
-	}
-
-	if (s_flags & SB_RDONLY) {
-		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
-		sb->s_flags &= ~SB_RDONLY;
-	}
-#ifdef CONFIG_QUOTA
-	/*
-	 * Turn on quotas which were not enabled for read-only mounts if
-	 * filesystem has quota feature, so that they are updated correctly.
-	 */
-	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
-		int ret = ext4_enable_quotas(sb);
-
-		if (!ret)
-			quota_update = 1;
-		else
-			ext4_msg(sb, KERN_ERR,
-				"Cannot turn on quotas: error %d", ret);
-	}
-
-	/* Turn on journaled quotas used for old sytle */
-	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
-		if (EXT4_SB(sb)->s_qf_names[i]) {
-			int ret = ext4_quota_on_mount(sb, i);
-
-			if (!ret)
-				quota_update = 1;
-			else
-				ext4_msg(sb, KERN_ERR,
-					"Cannot turn on journaled "
-					"quota: type %d: error %d", i, ret);
-		}
-	}
-#endif
-
-	while (es->s_last_orphan) {
-		struct inode *inode;
-
-		/*
-		 * We may have encountered an error during cleanup; if
-		 * so, skip the rest.
-		 */
-		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
-			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
-			es->s_last_orphan = 0;
-			break;
-		}
-
-		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
-		if (IS_ERR(inode)) {
-			es->s_last_orphan = 0;
-			break;
-		}
-
-		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
-		dquot_initialize(inode);
-		if (inode->i_nlink) {
-			if (test_opt(sb, DEBUG))
-				ext4_msg(sb, KERN_DEBUG,
-					"%s: truncating inode %lu to %lld bytes",
-					__func__, inode->i_ino, inode->i_size);
-			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
-				  inode->i_ino, inode->i_size);
-			inode_lock(inode);
-			truncate_inode_pages(inode->i_mapping, inode->i_size);
-			ret = ext4_truncate(inode);
-			if (ret) {
-				/*
-				 * We need to clean up the in-core orphan list
-				 * manually if ext4_truncate() failed to get a
-				 * transaction handle.
-				 */
-				ext4_orphan_del(NULL, inode);
-				ext4_std_error(inode->i_sb, ret);
-			}
-			inode_unlock(inode);
-			nr_truncates++;
-		} else {
-			if (test_opt(sb, DEBUG))
-				ext4_msg(sb, KERN_DEBUG,
-					"%s: deleting unreferenced inode %lu",
-					__func__, inode->i_ino);
-			jbd_debug(2, "deleting unreferenced inode %lu\n",
-				  inode->i_ino);
-			nr_orphans++;
-		}
-		iput(inode);  /* The delete magic happens here! */
-	}
-
-#define PLURAL(x) (x), ((x) == 1) ? "" : "s"
-
-	if (nr_orphans)
-		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
-		       PLURAL(nr_orphans));
-	if (nr_truncates)
-		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
-		       PLURAL(nr_truncates));
-#ifdef CONFIG_QUOTA
-	/* Turn off quotas if they were enabled for orphan cleanup */
-	if (quota_update) {
-		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
-			if (sb_dqopt(sb)->files[i])
-				dquot_quota_off(sb, i);
-		}
-	}
-#endif
-	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
-}
-
 /*
  * Maximal extent format file size.
  * Resulting logical blkno at s_maxbytes must fit in our on-disk
@@ -3312,7 +3146,7 @@ static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
  * Returns 1 if this filesystem can be mounted as requested,
  * 0 if it cannot be.
  */
-static int ext4_feature_set_ok(struct super_block *sb, int readonly)
+int ext4_feature_set_ok(struct super_block *sb, int readonly)
 {
 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
 		ext4_msg(sb, KERN_ERR,
@@ -6326,16 +6160,6 @@ static int ext4_write_info(struct super_block *sb, int type)
 	return ret;
 }
 
-/*
- * Turn on quotas during mount time - we need to find
- * the quota file and such...
- */
-static int ext4_quota_on_mount(struct super_block *sb, int type)
-{
-	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
-					EXT4_SB(sb)->s_jquota_fmt, type);
-}
-
 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
 {
 	struct ext4_inode_info *ei = EXT4_I(inode);
@@ -6465,7 +6289,7 @@ static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
 }
 
 /* Enable usage tracking for all quota types. */
-static int ext4_enable_quotas(struct super_block *sb)
+int ext4_enable_quotas(struct super_block *sb)
 {
 	int type, err = 0;
 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
-- 
2.26.2

[PATCH 3/5] ext4: Speedup ext4 orphan inode handling

[Jan Kara]

Ext4 orphan inode handling is a bottleneck for workloads which heavily
truncate / unlink small files since it contends on the global
s_orphan_mutex lock (and generally it's difficult to improve scalability
of the ondisk linked list of orphaned inodes).

This patch implements new way of handling orphan inodes. Instead of
linking orphaned inode into a linked list, we store it's inode number in
a new special file which we call "orphan file". Only if there's no more
space in the orphan file (too many inodes are currently orphaned) we
fall back to using old style linked list. Currently we protect
operations in the orphan file with a spinlock for simplicity but even in
this setting we can substantially reduce the length of the critical
section and thus speedup some workloads. In the next patch we improve
this by making orphan handling lockless.

Note that the change is backwards compatible when the filesystem is
clean - the existence of the orphan file is a compat feature, we set
another ro-compat feature indicating orphan file needs scanning for
orphaned inodes when mounting filesystem read-write. This ro-compat
feature gets cleared on unmount / remount read-only.

Some performance data from 80 CPU Xeon Server with 512 GB of RAM,
filesystem located on SSD, average of 5 runs:

stress-orphan (microbenchmark truncating files byte-by-byte from N
processes in parallel)

Threads Time            Time
        Vanilla         Patched
  1       1.057200        0.945600
  2       1.680400        1.331800
  4       2.547000        1.995000
  8       7.049400        6.424200
 16      14.827800       14.937600
 32      40.948200       33.038200
 64      87.787400       60.823600
128     206.504000      122.941400

So we can see significant wins all over the board.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/ext4/ext4.h   |  69 +++++++++-
 fs/ext4/orphan.c | 340 +++++++++++++++++++++++++++++++++++++++++------
 fs/ext4/super.c  |  34 ++++-
 3 files changed, 392 insertions(+), 51 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index b8194ea85fff..456d6efe6613 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1034,7 +1034,14 @@ struct ext4_inode_info {
 	 */
 	struct rw_semaphore xattr_sem;
 
-	struct list_head i_orphan;	/* unlinked but open inodes */
+	/*
+	 * Inodes with EXT4_STATE_ORPHAN_FILE use i_orphan_idx. Otherwise
+	 * i_orphan is used.
+	 */
+	union {
+		struct list_head i_orphan;	/* unlinked but open inodes */
+		unsigned int i_orphan_idx;	/* Index in orphan file */
+	};
 
 	/* Fast commit related info */
 
@@ -1428,7 +1435,8 @@ struct ext4_super_block {
 	__u8    s_last_error_errcode;
 	__le16  s_encoding;		/* Filename charset encoding */
 	__le16  s_encoding_flags;	/* Filename charset encoding flags */
-	__le32	s_reserved[95];		/* Padding to the end of the block */
+	__le32  s_orphan_file_inum;	/* Inode for tracking orphan inodes */
+	__le32	s_reserved[94];		/* Padding to the end of the block */
 	__le32	s_checksum;		/* crc32c(superblock) */
 };
 
@@ -1449,6 +1457,7 @@ struct ext4_super_block {
 
 /* Types of ext4 journal triggers */
 enum ext4_journal_trigger_type {
+	EXT4_JTR_ORPHAN_FILE,
 	EXT4_JTR_NONE	/* This must be the last entry for indexing to work! */
 };
 
@@ -1465,6 +1474,36 @@ static inline struct ext4_journal_trigger *EXT4_TRIGGER(
 	return container_of(trigger, struct ext4_journal_trigger, tr_triggers);
 }
 
+#define EXT4_ORPHAN_BLOCK_MAGIC 0x0b10ca04
+
+/* Structure at the tail of orphan block */
+struct ext4_orphan_block_tail {
+	__le32 ob_magic;
+	__le32 ob_checksum;
+};
+
+static inline int ext4_inodes_per_orphan_block(struct super_block *sb)
+{
+	return (sb->s_blocksize - sizeof(struct ext4_orphan_block_tail)) /
+			sizeof(u32);
+}
+
+struct ext4_orphan_block {
+	int ob_free_entries;	/* Number of free orphan entries in block */
+	struct buffer_head *ob_bh;	/* Buffer for orphan block */
+};
+
+/*
+ * Info about orphan file.
+ */
+struct ext4_orphan_info {
+	spinlock_t of_lock;
+	int of_blocks;			/* Number of orphan blocks in a file */
+	__u32 of_csum_seed;		/* Checksum seed for orphan file */
+	struct ext4_orphan_block *of_binfo;	/* Array with info about orphan
+						 * file blocks */
+};
+
 /*
  * fourth extended-fs super-block data in memory
  */
@@ -1519,9 +1558,11 @@ struct ext4_sb_info {
 
 	/* Journaling */
 	struct journal_s *s_journal;
-	struct list_head s_orphan;
-	struct mutex s_orphan_lock;
 	unsigned long s_ext4_flags;		/* Ext4 superblock flags */
+	struct mutex s_orphan_lock;	/* Protects on disk list changes */
+	struct list_head s_orphan;	/* List of orphaned inodes in on disk
+					   list */
+	struct ext4_orphan_info s_orphan_info;
 	unsigned long s_commit_interval;
 	u32 s_max_batch_time;
 	u32 s_min_batch_time;
@@ -1856,6 +1897,7 @@ enum {
 	EXT4_STATE_LUSTRE_EA_INODE,	/* Lustre-style ea_inode */
 	EXT4_STATE_VERITY_IN_PROGRESS,	/* building fs-verity Merkle tree */
 	EXT4_STATE_FC_COMMITTING,	/* Fast commit ongoing */
+	EXT4_STATE_ORPHAN_FILE,		/* Inode orphaned in orphan file */
 };
 
 #define EXT4_INODE_BIT_FNS(name, field, offset)				\
@@ -1957,6 +1999,7 @@ static inline bool ext4_verity_in_progress(struct inode *inode)
  */
 #define EXT4_FEATURE_COMPAT_FAST_COMMIT		0x0400
 #define EXT4_FEATURE_COMPAT_STABLE_INODES	0x0800
+#define EXT4_FEATURE_COMPAT_ORPHAN_FILE		0x1000	/* Orphan file exists */
 
 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
@@ -1977,6 +2020,8 @@ static inline bool ext4_verity_in_progress(struct inode *inode)
 #define EXT4_FEATURE_RO_COMPAT_READONLY		0x1000
 #define EXT4_FEATURE_RO_COMPAT_PROJECT		0x2000
 #define EXT4_FEATURE_RO_COMPAT_VERITY		0x8000
+#define EXT4_FEATURE_RO_COMPAT_ORPHAN_PRESENT	0x10000 /* Orphan file may be
+							   non-empty */
 
 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
@@ -2060,6 +2105,7 @@ EXT4_FEATURE_COMPAT_FUNCS(dir_index,		DIR_INDEX)
 EXT4_FEATURE_COMPAT_FUNCS(sparse_super2,	SPARSE_SUPER2)
 EXT4_FEATURE_COMPAT_FUNCS(fast_commit,		FAST_COMMIT)
 EXT4_FEATURE_COMPAT_FUNCS(stable_inodes,	STABLE_INODES)
+EXT4_FEATURE_COMPAT_FUNCS(orphan_file,		ORPHAN_FILE)
 
 EXT4_FEATURE_RO_COMPAT_FUNCS(sparse_super,	SPARSE_SUPER)
 EXT4_FEATURE_RO_COMPAT_FUNCS(large_file,	LARGE_FILE)
@@ -2074,6 +2120,7 @@ EXT4_FEATURE_RO_COMPAT_FUNCS(metadata_csum,	METADATA_CSUM)
 EXT4_FEATURE_RO_COMPAT_FUNCS(readonly,		READONLY)
 EXT4_FEATURE_RO_COMPAT_FUNCS(project,		PROJECT)
 EXT4_FEATURE_RO_COMPAT_FUNCS(verity,		VERITY)
+EXT4_FEATURE_RO_COMPAT_FUNCS(orphan_present,	ORPHAN_PRESENT)
 
 EXT4_FEATURE_INCOMPAT_FUNCS(compression,	COMPRESSION)
 EXT4_FEATURE_INCOMPAT_FUNCS(filetype,		FILETYPE)
@@ -2107,7 +2154,8 @@ EXT4_FEATURE_INCOMPAT_FUNCS(casefold,		CASEFOLD)
 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
 
-#define EXT4_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
+#define EXT4_FEATURE_COMPAT_SUPP	(EXT4_FEATURE_COMPAT_EXT_ATTR| \
+					 EXT4_FEATURE_COMPAT_ORPHAN_FILE)
 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
 					 EXT4_FEATURE_INCOMPAT_META_BG| \
@@ -2132,7 +2180,8 @@ EXT4_FEATURE_INCOMPAT_FUNCS(casefold,		CASEFOLD)
 					 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
 					 EXT4_FEATURE_RO_COMPAT_QUOTA |\
 					 EXT4_FEATURE_RO_COMPAT_PROJECT |\
-					 EXT4_FEATURE_RO_COMPAT_VERITY)
+					 EXT4_FEATURE_RO_COMPAT_VERITY |\
+					 EXT4_FEATURE_RO_COMPAT_ORPHAN_PRESENT)
 
 #define EXTN_FEATURE_FUNCS(ver) \
 static inline bool ext4_has_unknown_ext##ver##_compat_features(struct super_block *sb) \
@@ -2182,7 +2231,6 @@ static inline int ext4_forced_shutdown(struct ext4_sb_info *sbi)
 	return test_bit(EXT4_FLAGS_SHUTDOWN, &sbi->s_ext4_flags);
 }
 
-
 /*
  * Default values for user and/or group using reserved blocks
  */
@@ -3765,6 +3813,13 @@ extern int ext4_orphan_add(handle_t *, struct inode *);
 extern int ext4_orphan_del(handle_t *, struct inode *);
 extern void ext4_orphan_cleanup(struct super_block *sb,
 				struct ext4_super_block *es);
+extern void ext4_release_orphan_info(struct super_block *sb);
+extern int ext4_init_orphan_info(struct super_block *sb);
+extern int ext4_orphan_file_empty(struct super_block *sb);
+extern void ext4_orphan_file_block_trigger(
+				struct jbd2_buffer_trigger_type *triggers,
+				struct buffer_head *bh,
+				void *data, size_t size);
 
 /*
  * Add new method to test whether block and inode bitmaps are properly
diff --git a/fs/ext4/orphan.c b/fs/ext4/orphan.c
index 1f2fa2ef53bd..019719c0ac12 100644
--- a/fs/ext4/orphan.c
+++ b/fs/ext4/orphan.c
@@ -8,6 +8,52 @@
 #include "ext4.h"
 #include "ext4_jbd2.h"
 
+static int ext4_orphan_file_add(handle_t *handle, struct inode *inode)
+{
+	int i, j;
+	struct ext4_orphan_info *oi = &EXT4_SB(inode->i_sb)->s_orphan_info;
+	int ret = 0;
+	__le32 *bdata;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(inode->i_sb);
+
+	spin_lock(&oi->of_lock);
+	for (i = 0; i < oi->of_blocks && !oi->of_binfo[i].ob_free_entries; i++);
+	if (i == oi->of_blocks) {
+		spin_unlock(&oi->of_lock);
+		/*
+		 * For now we don't grow or shrink orphan file. We just use
+		 * whatever was allocated at mke2fs time. The additional
+		 * credits we would have to reserve for each orphan inode
+		 * operation just don't seem worth it.
+		 */
+		return -ENOSPC;
+	}
+	oi->of_binfo[i].ob_free_entries--;
+	spin_unlock(&oi->of_lock);
+
+	/*
+	 * Get access to orphan block. We have dropped of_lock but since we
+	 * have decremented number of free entries we are guaranteed free entry
+	 * in our block.
+	 */
+	ret = ext4_journal_get_write_access(handle, inode->i_sb,
+				oi->of_binfo[i].ob_bh, EXT4_JTR_ORPHAN_FILE);
+	if (ret)
+		return ret;
+
+	bdata = (__le32 *)(oi->of_binfo[i].ob_bh->b_data);
+	spin_lock(&oi->of_lock);
+	/* Find empty slot in a block */
+	for (j = 0; j < inodes_per_ob && bdata[j]; j++);
+	BUG_ON(j == inodes_per_ob);
+	bdata[j] = cpu_to_le32(inode->i_ino);
+	EXT4_I(inode)->i_orphan_idx = i * inodes_per_ob + j;
+	ext4_set_inode_state(inode, EXT4_STATE_ORPHAN_FILE);
+	spin_unlock(&oi->of_lock);
+
+	return ext4_handle_dirty_metadata(handle, NULL, oi->of_binfo[i].ob_bh);
+}
+
 /*
  * ext4_orphan_add() links an unlinked or truncated inode into a list of
  * such inodes, starting at the superblock, in case we crash before the
@@ -34,10 +80,10 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode)
 	WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
 		     !inode_is_locked(inode));
 	/*
-	 * Exit early if inode already is on orphan list. This is a big speedup
-	 * since we don't have to contend on the global s_orphan_lock.
+	 * Inode orphaned in orphan file or in orphan list?
 	 */
-	if (!list_empty(&EXT4_I(inode)->i_orphan))
+	if (ext4_test_inode_state(inode, EXT4_STATE_ORPHAN_FILE) ||
+	    !list_empty(&EXT4_I(inode)->i_orphan))
 		return 0;
 
 	/*
@@ -49,6 +95,16 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode)
 	ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 		  S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
 
+	if (sbi->s_orphan_info.of_blocks) {
+		err = ext4_orphan_file_add(handle, inode);
+		/*
+		 * Fallback to normal orphan list of orphan file is
+		 * out of space
+		 */
+		if (err != -ENOSPC)
+			return err;
+	}
+
 	BUFFER_TRACE(sbi->s_sbh, "get_write_access");
 	err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,
 					    EXT4_JTR_NONE);
@@ -103,6 +159,39 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode)
 	return err;
 }
 
+static int ext4_orphan_file_del(handle_t *handle, struct inode *inode)
+{
+	struct ext4_orphan_info *oi = &EXT4_SB(inode->i_sb)->s_orphan_info;
+	__le32 *bdata;
+	int blk, off;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(inode->i_sb);
+	int ret = 0;
+
+	if (!handle)
+		goto out;
+	blk = EXT4_I(inode)->i_orphan_idx / inodes_per_ob;
+	off = EXT4_I(inode)->i_orphan_idx % inodes_per_ob;
+	if (WARN_ON_ONCE(blk >= oi->of_blocks))
+		goto out;
+
+	ret = ext4_journal_get_write_access(handle, inode->i_sb,
+				oi->of_binfo[blk].ob_bh, EXT4_JTR_ORPHAN_FILE);
+	if (ret)
+		goto out;
+
+	bdata = (__le32 *)(oi->of_binfo[blk].ob_bh->b_data);
+	spin_lock(&oi->of_lock);
+	bdata[off] = 0;
+	oi->of_binfo[blk].ob_free_entries++;
+	spin_unlock(&oi->of_lock);
+	ret = ext4_handle_dirty_metadata(handle, NULL, oi->of_binfo[blk].ob_bh);
+out:
+	ext4_clear_inode_state(inode, EXT4_STATE_ORPHAN_FILE);
+	INIT_LIST_HEAD(&EXT4_I(inode)->i_orphan);
+
+	return ret;
+}
+
 /*
  * ext4_orphan_del() removes an unlinked or truncated inode from the list
  * of such inodes stored on disk, because it is finally being cleaned up.
@@ -121,6 +210,9 @@ int ext4_orphan_del(handle_t *handle, struct inode *inode)
 
 	WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
 		     !inode_is_locked(inode));
+	if (ext4_test_inode_state(inode, EXT4_STATE_ORPHAN_FILE))
+		return ext4_orphan_file_del(handle, inode);
+
 	/* Do this quick check before taking global s_orphan_lock. */
 	if (list_empty(&ei->i_orphan))
 		return 0;
@@ -200,6 +292,46 @@ static int ext4_quota_on_mount(struct super_block *sb, int type)
 }
 #endif
 
+static void ext4_process_orphan(struct inode *inode,
+				int *nr_truncates, int *nr_orphans)
+{
+	struct super_block *sb = inode->i_sb;
+	int ret;
+
+	dquot_initialize(inode);
+	if (inode->i_nlink) {
+		if (test_opt(sb, DEBUG))
+			ext4_msg(sb, KERN_DEBUG,
+				"%s: truncating inode %lu to %lld bytes",
+				__func__, inode->i_ino, inode->i_size);
+		jbd_debug(2, "truncating inode %lu to %lld bytes\n",
+			  inode->i_ino, inode->i_size);
+		inode_lock(inode);
+		truncate_inode_pages(inode->i_mapping, inode->i_size);
+		ret = ext4_truncate(inode);
+		if (ret) {
+			/*
+			 * We need to clean up the in-core orphan list
+			 * manually if ext4_truncate() failed to get a
+			 * transaction handle.
+			 */
+			ext4_orphan_del(NULL, inode);
+			ext4_std_error(inode->i_sb, ret);
+		}
+		inode_unlock(inode);
+		(*nr_truncates)++;
+	} else {
+		if (test_opt(sb, DEBUG))
+			ext4_msg(sb, KERN_DEBUG,
+				"%s: deleting unreferenced inode %lu",
+				__func__, inode->i_ino);
+		jbd_debug(2, "deleting unreferenced inode %lu\n",
+			  inode->i_ino);
+		(*nr_orphans)++;
+	}
+	iput(inode);  /* The delete magic happens here! */
+}
+
 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
  * the superblock) which were deleted from all directories, but held open by
  * a process at the time of a crash.  We walk the list and try to delete these
@@ -220,12 +352,17 @@ static int ext4_quota_on_mount(struct super_block *sb, int type)
 void ext4_orphan_cleanup(struct super_block *sb, struct ext4_super_block *es)
 {
 	unsigned int s_flags = sb->s_flags;
-	int ret, nr_orphans = 0, nr_truncates = 0;
+	int nr_orphans = 0, nr_truncates = 0;
+	struct inode *inode;
+	int i, j;
 #ifdef CONFIG_QUOTA
 	int quota_update = 0;
-	int i;
 #endif
-	if (!es->s_last_orphan) {
+	__le32 *bdata;
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
+
+	if (!es->s_last_orphan && !oi->of_blocks) {
 		jbd_debug(4, "no orphan inodes to clean up\n");
 		return;
 	}
@@ -289,8 +426,6 @@ void ext4_orphan_cleanup(struct super_block *sb, struct ext4_super_block *es)
 #endif
 
 	while (es->s_last_orphan) {
-		struct inode *inode;
-
 		/*
 		 * We may have encountered an error during cleanup; if
 		 * so, skip the rest.
@@ -308,38 +443,21 @@ void ext4_orphan_cleanup(struct super_block *sb, struct ext4_super_block *es)
 		}
 
 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
-		dquot_initialize(inode);
-		if (inode->i_nlink) {
-			if (test_opt(sb, DEBUG))
-				ext4_msg(sb, KERN_DEBUG,
-					"%s: truncating inode %lu to %lld bytes",
-					__func__, inode->i_ino, inode->i_size);
-			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
-				  inode->i_ino, inode->i_size);
-			inode_lock(inode);
-			truncate_inode_pages(inode->i_mapping, inode->i_size);
-			ret = ext4_truncate(inode);
-			if (ret) {
-				/*
-				 * We need to clean up the in-core orphan list
-				 * manually if ext4_truncate() failed to get a
-				 * transaction handle.
-				 */
-				ext4_orphan_del(NULL, inode);
-				ext4_std_error(inode->i_sb, ret);
-			}
-			inode_unlock(inode);
-			nr_truncates++;
-		} else {
-			if (test_opt(sb, DEBUG))
-				ext4_msg(sb, KERN_DEBUG,
-					"%s: deleting unreferenced inode %lu",
-					__func__, inode->i_ino);
-			jbd_debug(2, "deleting unreferenced inode %lu\n",
-				  inode->i_ino);
-			nr_orphans++;
+		ext4_process_orphan(inode, &nr_truncates, &nr_orphans);
+	}
+
+	for (i = 0; i < oi->of_blocks; i++) {
+		bdata = (__le32 *)(oi->of_binfo[i].ob_bh->b_data);
+		for (j = 0; j < inodes_per_ob; j++) {
+			if (!bdata[j])
+				continue;
+			inode = ext4_orphan_get(sb, le32_to_cpu(bdata[j]));
+			if (IS_ERR(inode))
+				continue;
+			ext4_set_inode_state(inode, EXT4_STATE_ORPHAN_FILE);
+			EXT4_I(inode)->i_orphan_idx = i * inodes_per_ob + j;
+			ext4_process_orphan(inode, &nr_truncates, &nr_orphans);
 		}
-		iput(inode);  /* The delete magic happens here! */
 	}
 
 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
@@ -361,3 +479,147 @@ void ext4_orphan_cleanup(struct super_block *sb, struct ext4_super_block *es)
 #endif
 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
 }
+
+void ext4_release_orphan_info(struct super_block *sb)
+{
+	int i;
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+
+	if (!oi->of_blocks)
+		return;
+	for (i = 0; i < oi->of_blocks; i++)
+		brelse(oi->of_binfo[i].ob_bh);
+	kfree(oi->of_binfo);
+}
+
+static struct ext4_orphan_block_tail *ext4_orphan_block_tail(
+						struct super_block *sb,
+						struct buffer_head *bh)
+{
+	return (struct ext4_orphan_block_tail *)(bh->b_data + sb->s_blocksize -
+				sizeof(struct ext4_orphan_block_tail));
+}
+
+static int ext4_orphan_file_block_csum_verify(struct super_block *sb,
+					      struct buffer_head *bh)
+{
+	__u32 calculated;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+	struct ext4_orphan_block_tail *ot;
+	__le64 dsk_block_nr = cpu_to_le64(bh->b_blocknr);
+
+	if (!ext4_has_metadata_csum(sb))
+		return 1;
+
+	ot = ext4_orphan_block_tail(sb, bh);
+	calculated = ext4_chksum(EXT4_SB(sb), oi->of_csum_seed,
+				 (__u8 *)&dsk_block_nr, sizeof(dsk_block_nr));
+	calculated = ext4_chksum(EXT4_SB(sb), calculated, (__u8 *)bh->b_data,
+				 inodes_per_ob * sizeof(__u32));
+	return le32_to_cpu(ot->ob_checksum) == calculated;
+}
+
+/* This gets called only when checksumming is enabled */
+void ext4_orphan_file_block_trigger(struct jbd2_buffer_trigger_type *triggers,
+				    struct buffer_head *bh,
+				    void *data, size_t size)
+{
+	struct super_block *sb = EXT4_TRIGGER(triggers)->sb;
+	__u32 csum;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+	struct ext4_orphan_block_tail *ot;
+	__le64 dsk_block_nr = cpu_to_le64(bh->b_blocknr);
+
+	csum = ext4_chksum(EXT4_SB(sb), oi->of_csum_seed,
+			   (__u8 *)&dsk_block_nr, sizeof(dsk_block_nr));
+	csum = ext4_chksum(EXT4_SB(sb), csum, (__u8 *)data,
+			   inodes_per_ob * sizeof(__u32));
+	ot = ext4_orphan_block_tail(sb, bh);
+	ot->ob_checksum = cpu_to_le32(csum);
+}
+
+int ext4_init_orphan_info(struct super_block *sb)
+{
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+	struct inode *inode;
+	int i, j;
+	int ret;
+	int free;
+	__le32 *bdata;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
+	struct ext4_orphan_block_tail *ot;
+	ino_t orphan_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_orphan_file_inum);
+
+	spin_lock_init(&oi->of_lock);
+
+	if (!ext4_has_feature_orphan_file(sb))
+		return 0;
+
+	inode = ext4_iget(sb, orphan_ino, EXT4_IGET_NORMAL);
+	if (IS_ERR(inode)) {
+		ext4_msg(sb, KERN_ERR, "get orphan inode failed");
+		return PTR_ERR(inode);
+	}
+	oi->of_blocks = inode->i_size >> sb->s_blocksize_bits;
+	oi->of_csum_seed = EXT4_I(inode)->i_csum_seed;
+	oi->of_binfo = kmalloc(oi->of_blocks*sizeof(struct ext4_orphan_block),
+			       GFP_KERNEL);
+	if (!oi->of_binfo) {
+		ret = -ENOMEM;
+		goto out_put;
+	}
+	for (i = 0; i < oi->of_blocks; i++) {
+		oi->of_binfo[i].ob_bh = ext4_bread(NULL, inode, i, 0);
+		if (IS_ERR(oi->of_binfo[i].ob_bh)) {
+			ret = PTR_ERR(oi->of_binfo[i].ob_bh);
+			goto out_free;
+		}
+		if (!oi->of_binfo[i].ob_bh) {
+			ret = -EIO;
+			goto out_free;
+		}
+		ot = ext4_orphan_block_tail(sb, oi->of_binfo[i].ob_bh);
+		if (le32_to_cpu(ot->ob_magic) != EXT4_ORPHAN_BLOCK_MAGIC) {
+			ext4_error(sb, "orphan file block %d: bad magic", i);
+			ret = -EIO;
+			goto out_free;
+		}
+		if (!ext4_orphan_file_block_csum_verify(sb,
+						oi->of_binfo[i].ob_bh)) {
+			ext4_error(sb, "orphan file block %d: bad checksum", i);
+			ret = -EIO;
+			goto out_free;
+		}
+		bdata = (__le32 *)(oi->of_binfo[i].ob_bh->b_data);
+		free = 0;
+		for (j = 0; j < inodes_per_ob; j++)
+			if (bdata[j] == 0)
+				free++;
+		oi->of_binfo[i].ob_free_entries = free;
+	}
+	iput(inode);
+	return 0;
+out_free:
+	for (i--; i >= 0; i--)
+		brelse(oi->of_binfo[i].ob_bh);
+	kfree(oi->of_binfo);
+out_put:
+	iput(inode);
+	return ret;
+}
+
+int ext4_orphan_file_empty(struct super_block *sb)
+{
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+	int i;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
+
+	if (!ext4_has_feature_orphan_file(sb))
+		return 1;
+	for (i = 0; i < oi->of_blocks; i++)
+		if (oi->of_binfo[i].ob_free_entries != inodes_per_ob)
+			return 0;
+	return 1;
+}
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index a7081d525faa..0715f5a5bb88 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1174,6 +1174,7 @@ static void ext4_put_super(struct super_block *sb)
 
 	flush_work(&sbi->s_error_work);
 	destroy_workqueue(sbi->rsv_conversion_wq);
+	ext4_release_orphan_info(sb);
 
 	/*
 	 * Unregister sysfs before destroying jbd2 journal.
@@ -1199,6 +1200,7 @@ static void ext4_put_super(struct super_block *sb)
 
 	if (!sb_rdonly(sb) && !aborted) {
 		ext4_clear_feature_journal_needs_recovery(sb);
+		ext4_clear_feature_orphan_present(sb);
 		es->s_state = cpu_to_le16(sbi->s_mount_state);
 	}
 	if (!sb_rdonly(sb))
@@ -2684,8 +2686,11 @@ static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
 	le16_add_cpu(&es->s_mnt_count, 1);
 	ext4_update_tstamp(es, s_mtime);
-	if (sbi->s_journal)
+	if (sbi->s_journal) {
 		ext4_set_feature_journal_needs_recovery(sb);
+		if (ext4_has_feature_orphan_file(sb))
+			ext4_set_feature_orphan_present(sb);
+	}
 
 	err = ext4_commit_super(sb);
 done:
@@ -3960,6 +3965,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		silent = 1;
 		goto cantfind_ext4;
 	}
+	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
+				ext4_orphan_file_block_trigger);
 
 	/* Load the checksum driver */
 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
@@ -4624,6 +4631,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_root = NULL;
 
 	needs_recovery = (es->s_last_orphan != 0 ||
+			  ext4_has_feature_orphan_present(sb) ||
 			  ext4_has_feature_journal_needs_recovery(sb));
 
 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
@@ -4914,12 +4922,15 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	if (err)
 		goto failed_mount7;
 
+	err = ext4_init_orphan_info(sb);
+	if (err)
+		goto failed_mount8;
 #ifdef CONFIG_QUOTA
 	/* Enable quota usage during mount. */
 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
 		err = ext4_enable_quotas(sb);
 		if (err)
-			goto failed_mount8;
+			goto failed_mount9;
 	}
 #endif  /* CONFIG_QUOTA */
 
@@ -4938,7 +4949,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		ext4_msg(sb, KERN_INFO, "recovery complete");
 		err = ext4_mark_recovery_complete(sb, es);
 		if (err)
-			goto failed_mount8;
+			goto failed_mount9;
 	}
 	if (EXT4_SB(sb)->s_journal) {
 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
@@ -4984,6 +4995,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
 	goto failed_mount;
 
+failed_mount9:
+	ext4_release_orphan_info(sb);
 failed_mount8:
 	ext4_unregister_sysfs(sb);
 	kobject_put(&sbi->s_kobj);
@@ -5494,8 +5507,15 @@ static int ext4_mark_recovery_complete(struct super_block *sb,
 	if (err < 0)
 		goto out;
 
-	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
+	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
+	    ext4_has_feature_orphan_present(sb))) {
+		if (!ext4_orphan_file_empty(sb)) {
+			ext4_error(sb, "Orphan file not empty on read-only fs.");
+			err = -EFSCORRUPTED;
+			goto out;
+		}
 		ext4_clear_feature_journal_needs_recovery(sb);
+		ext4_clear_feature_orphan_present(sb);
 		ext4_commit_super(sb);
 	}
 out:
@@ -5638,6 +5658,8 @@ static int ext4_freeze(struct super_block *sb)
 
 		/* Journal blocked and flushed, clear needs_recovery flag. */
 		ext4_clear_feature_journal_needs_recovery(sb);
+		if (ext4_orphan_file_empty(sb))
+			ext4_clear_feature_orphan_present(sb);
 	}
 
 	error = ext4_commit_super(sb);
@@ -5660,6 +5682,8 @@ static int ext4_unfreeze(struct super_block *sb)
 	if (EXT4_SB(sb)->s_journal) {
 		/* Reset the needs_recovery flag before the fs is unlocked. */
 		ext4_set_feature_journal_needs_recovery(sb);
+		if (ext4_has_feature_orphan_file(sb))
+			ext4_set_feature_orphan_present(sb);
 	}
 
 	ext4_commit_super(sb);
@@ -5863,7 +5887,7 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 			 * around from a previously readonly bdev mount,
 			 * require a full umount/remount for now.
 			 */
-			if (es->s_last_orphan) {
+			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
 				ext4_msg(sb, KERN_WARNING, "Couldn't "
 				       "remount RDWR because of unprocessed "
 				       "orphan inode list.  Please "
-- 
2.26.2

Re: [PATCH 3/5] ext4: Speedup ext4 orphan inode handling

[Theodore Ts'o]

On Wed, Aug 11, 2021 at 12:19:13PM +0200, Jan Kara wrote:
> +static int ext4_orphan_file_del(handle_t *handle, struct inode *inode)
> +{
> +	struct ext4_orphan_info *oi = &EXT4_SB(inode->i_sb)->s_orphan_info;
> +	__le32 *bdata;
> +	int blk, off;
> +	int inodes_per_ob = ext4_inodes_per_orphan_block(inode->i_sb);
> +	int ret = 0;
> +
> +	if (!handle)
> +		goto out;
> +	blk = EXT4_I(inode)->i_orphan_idx / inodes_per_ob;
> +	off = EXT4_I(inode)->i_orphan_idx % inodes_per_ob;
> +	if (WARN_ON_ONCE(blk >= oi->of_blocks))
> +		goto out;
> +
> +	ret = ext4_journal_get_write_access(handle, inode->i_sb,
> +				oi->of_binfo[blk].ob_bh, EXT4_JTR_ORPHAN_FILE);
> +	if (ret)
> +		goto out;

If ext4_journal_get_write_access() fails, we effectively drop the
inode from the orphan list (as far as the in-memory inode is
concerned), although the inode will still be listed in the orphan
file.  This can be really unfortunate since if the inode gets
reallocated for some other purpose, since its inode number is left in
the orphan block, on the next remount, this could lead to data loss.

In the orphan list code, we leave the inode on the linked list, which
is not great, since that will prevent the inode from being freed, but
at least we're keeping the in-memory and on-disk state in sync and we
avoid the data loss scenario when the inode gets reused.

I'll also note that all or at least most of the callers of
ext4_orphan_del() are doing error checking, which also unfortunate
(although what are we supposed to do in case of a failure here?).

I think keeping things consistent with the existing non-optimal "error
handle" at least makes things no worse than before, but looking at the
error handling, I'm left with a sense of unease.  What do you think?

      		    	      	      - Ted

Re: [PATCH 3/5] ext4: Speedup ext4 orphan inode handling

[Jan Kara]

On Thu 12-08-21 11:01:34, Theodore Ts'o wrote:
> On Wed, Aug 11, 2021 at 12:19:13PM +0200, Jan Kara wrote:
> > +static int ext4_orphan_file_del(handle_t *handle, struct inode *inode)
> > +{
> > +	struct ext4_orphan_info *oi = &EXT4_SB(inode->i_sb)->s_orphan_info;
> > +	__le32 *bdata;
> > +	int blk, off;
> > +	int inodes_per_ob = ext4_inodes_per_orphan_block(inode->i_sb);
> > +	int ret = 0;
> > +
> > +	if (!handle)
> > +		goto out;
> > +	blk = EXT4_I(inode)->i_orphan_idx / inodes_per_ob;
> > +	off = EXT4_I(inode)->i_orphan_idx % inodes_per_ob;
> > +	if (WARN_ON_ONCE(blk >= oi->of_blocks))
> > +		goto out;
> > +
> > +	ret = ext4_journal_get_write_access(handle, inode->i_sb,
> > +				oi->of_binfo[blk].ob_bh, EXT4_JTR_ORPHAN_FILE);
> > +	if (ret)
> > +		goto out;
> 
> If ext4_journal_get_write_access() fails, we effectively drop the
> inode from the orphan list (as far as the in-memory inode is
> concerned), although the inode will still be listed in the orphan
> file.  This can be really unfortunate since if the inode gets
> reallocated for some other purpose, since its inode number is left in
> the orphan block, on the next remount, this could lead to data loss.
> 
> In the orphan list code, we leave the inode on the linked list, which
> is not great, since that will prevent the inode from being freed, but
> at least we're keeping the in-memory and on-disk state in sync and we
> avoid the data loss scenario when the inode gets reused.

Actually, in the orphan list code, we leave the inode in the on-disk list
but remove it from the in-memory list - see how
list_del_init(&ei->i_orphan) is called very early in ext4_orphan_del(). The
reason for this unconditional deletion is that if we do not remove the
inode from the in-memory orphan list, the filesystem will complain and
corrupt memory on unmount.

Also note that leaving inode in the on-disk orphan list actually does no
serious harm. Because the orphan cleanup code just checks i_nlink and
i_disksize and truncates inode down to current i_disksize and removes inode
completely if i_nlink is 0. So even if an inode on the orphan list gets
reused, orphan cleanup will just do nothing for it. So the worst problem
that will likely happen is that on-disk orphan linked list becomes
corrupted but there's no data loss AFAICT.

Is it clearer now or am I missing something?

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

Re: [PATCH 3/5] ext4: Speedup ext4 orphan inode handling

[Theodore Ts'o]

On Fri, Aug 13, 2021 at 02:34:34PM +0200, Jan Kara wrote:
> Actually, in the orphan list code, we leave the inode in the on-disk list
> but remove it from the in-memory list - see how
> list_del_init(&ei->i_orphan) is called very early in ext4_orphan_del(). The
> reason for this unconditional deletion is that if we do not remove the
> inode from the in-memory orphan list, the filesystem will complain and
> corrupt memory on unmount.
> 
> Also note that leaving inode in the on-disk orphan list actually does no
> serious harm. Because the orphan cleanup code just checks i_nlink and
> i_disksize and truncates inode down to current i_disksize and removes inode
> completely if i_nlink is 0. So even if an inode on the orphan list gets
> reused, orphan cleanup will just do nothing for it. So the worst problem
> that will likely happen is that on-disk orphan linked list becomes
> corrupted but there's no data loss AFAICT.
> 
> Is it clearer now or am I missing something?

Yes, you're right, I misread the code.  Thanks for clarifying.

Can you send the final spin of this patch set?  I think we're all set
for this patch series.

Reviewed-by: Theodore Ts'o <tytso@mit.edu>

						- Ted

Re: [PATCH 3/5] ext4: Speedup ext4 orphan inode handling

[Jan Kara]

On Fri 13-08-21 11:26:45, Theodore Ts'o wrote:
> On Fri, Aug 13, 2021 at 02:34:34PM +0200, Jan Kara wrote:
> > Actually, in the orphan list code, we leave the inode in the on-disk list
> > but remove it from the in-memory list - see how
> > list_del_init(&ei->i_orphan) is called very early in ext4_orphan_del(). The
> > reason for this unconditional deletion is that if we do not remove the
> > inode from the in-memory orphan list, the filesystem will complain and
> > corrupt memory on unmount.
> > 
> > Also note that leaving inode in the on-disk orphan list actually does no
> > serious harm. Because the orphan cleanup code just checks i_nlink and
> > i_disksize and truncates inode down to current i_disksize and removes inode
> > completely if i_nlink is 0. So even if an inode on the orphan list gets
> > reused, orphan cleanup will just do nothing for it. So the worst problem
> > that will likely happen is that on-disk orphan linked list becomes
> > corrupted but there's no data loss AFAICT.
> > 
> > Is it clearer now or am I missing something?
> 
> Yes, you're right, I misread the code.  Thanks for clarifying.
> 
> Can you send the final spin of this patch set?  I think we're all set
> for this patch series.
> 
> Reviewed-by: Theodore Ts'o <tytso@mit.edu>

Thanks. I've posted v6 with all the updates.

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

[PATCH 4/5] ext4: Orphan file documentation

[Jan Kara]

Add documentation about the orphan file feature.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 Documentation/filesystems/ext4/globals.rst    |  1 +
 Documentation/filesystems/ext4/inodes.rst     | 10 ++--
 Documentation/filesystems/ext4/orphan.rst     | 52 +++++++++++++++++++
 .../filesystems/ext4/special_inodes.rst       | 17 ++++++
 Documentation/filesystems/ext4/super.rst      | 15 +++++-
 5 files changed, 89 insertions(+), 6 deletions(-)
 create mode 100644 Documentation/filesystems/ext4/orphan.rst

diff --git a/Documentation/filesystems/ext4/globals.rst b/Documentation/filesystems/ext4/globals.rst
index 368bf7662b96..b17418974fd3 100644
--- a/Documentation/filesystems/ext4/globals.rst
+++ b/Documentation/filesystems/ext4/globals.rst
@@ -11,3 +11,4 @@ have static metadata at fixed locations.
 .. include:: bitmaps.rst
 .. include:: mmp.rst
 .. include:: journal.rst
+.. include:: orphan.rst
diff --git a/Documentation/filesystems/ext4/inodes.rst b/Documentation/filesystems/ext4/inodes.rst
index a65baffb4ebf..6c5ce666e63f 100644
--- a/Documentation/filesystems/ext4/inodes.rst
+++ b/Documentation/filesystems/ext4/inodes.rst
@@ -498,11 +498,11 @@ structure -- inode change time (ctime), access time (atime), data
 modification time (mtime), and deletion time (dtime). The four fields
 are 32-bit signed integers that represent seconds since the Unix epoch
 (1970-01-01 00:00:00 GMT), which means that the fields will overflow in
-January 2038. For inodes that are not linked from any directory but are
-still open (orphan inodes), the dtime field is overloaded for use with
-the orphan list. The superblock field ``s_last_orphan`` points to the
-first inode in the orphan list; dtime is then the number of the next
-orphaned inode, or zero if there are no more orphans.
+January 2038. If the filesystem does not have orphan_file feature, inodes
+that are not linked from any directory but are still open (orphan inodes) have
+the dtime field overloaded for use with the orphan list. The superblock field
+``s_last_orphan`` points to the first inode in the orphan list; dtime is then
+the number of the next orphaned inode, or zero if there are no more orphans.
 
 If the inode structure size ``sb->s_inode_size`` is larger than 128
 bytes and the ``i_inode_extra`` field is large enough to encompass the
diff --git a/Documentation/filesystems/ext4/orphan.rst b/Documentation/filesystems/ext4/orphan.rst
new file mode 100644
index 000000000000..bb19ecd1b626
--- /dev/null
+++ b/Documentation/filesystems/ext4/orphan.rst
@@ -0,0 +1,52 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Orphan file
+-----------
+
+In unix there can inodes that are unlinked from directory hierarchy but that
+are still alive because they are open. In case of crash the filesystem has to
+clean up these inodes as otherwise they (and the blocks referenced from them)
+would leak. Similarly if we truncate or extend the file, we need not be able
+to perform the operation in a single journalling transaction. In such case we
+track the inode as orphan so that in case of crash extra blocks allocated to
+the file get truncated.
+
+Traditionally ext4 tracks orphan inodes in a form of single linked list where
+superblock contains the inode number of the last orphan inode (s\_last\_orphan
+field) and then each inode contains inode number of the previously orphaned
+inode (we overload i\_dtime inode field for this). However this filesystem
+global single linked list is a scalability bottleneck for workloads that result
+in heavy creation of orphan inodes. When orphan file feature
+(COMPAT\_ORPHAN\_FILE) is enabled, the filesystem has a special inode
+(referenced from the superblock through s\_orphan_file_inum) with several
+blocks. Each of these blocks has a structure:
+
+.. list-table::
+   :widths: 8 8 24 40
+   :header-rows: 1
+
+   * - Offset
+     - Type
+     - Name
+     - Description
+   * - 0x0
+     - Array of \_\_le32 entries
+     - Orphan inode entries
+     - Each \_\_le32 entry is either empty (0) or it contains inode number of
+       an orphan inode.
+   * - blocksize - 8
+     - \_\_le32
+     - ob\_magic
+     - Magic value stored in orphan block tail (0x0b10ca04)
+   * - blocksize - 4
+     - \_\_le32
+     - ob\_checksum
+     - Checksum of the orphan block.
+
+When a filesystem with orphan file feature is writeably mounted, we set
+RO\_COMPAT\_ORPHAN\_PRESENT feature in the superblock to indicate there may
+be valid orphan entries. In case we see this feature when mounting the
+filesystem, we read the whole orphan file and process all orphan inodes found
+there as usual. When cleanly unmounting the filesystem we remove the
+RO\_COMPAT\_ORPHAN\_PRESENT feature to avoid unnecessary scanning of the orphan
+file and also make the filesystem fully compatible with older kernels.
diff --git a/Documentation/filesystems/ext4/special_inodes.rst b/Documentation/filesystems/ext4/special_inodes.rst
index 9061aabba827..94f304e3a0a7 100644
--- a/Documentation/filesystems/ext4/special_inodes.rst
+++ b/Documentation/filesystems/ext4/special_inodes.rst
@@ -36,3 +36,20 @@ ext4 reserves some inode for special features, as follows:
    * - 11
      - Traditional first non-reserved inode. Usually this is the lost+found directory. See s\_first\_ino in the superblock.
 
+Note that there are also some inodes allocated from non-reserved inode numbers
+for other filesystem features which are not referenced from standard directory
+hierarchy. These are generally reference from the superblock. They are:
+
+.. list-table::
+   :widths: 20 50
+   :header-rows: 1
+
+   * - Superblock field
+     - Description
+
+   * - s\_lpf\_ino
+     - Inode number of lost+found directory.
+   * - s\_prj\_quota\_inum
+     - Inode number of quota file tracking project quotas
+   * - s\_orphan\_file\_inum
+     - Inode number of file tracking orphan inodes.
diff --git a/Documentation/filesystems/ext4/super.rst b/Documentation/filesystems/ext4/super.rst
index 2eb1ab20498d..f6a548e957bb 100644
--- a/Documentation/filesystems/ext4/super.rst
+++ b/Documentation/filesystems/ext4/super.rst
@@ -479,7 +479,11 @@ The ext4 superblock is laid out as follows in
      - Filename charset encoding flags.
    * - 0x280
      - \_\_le32
-     - s\_reserved[95]
+     - s\_orphan\_file\_inum
+     - Orphan file inode number.
+   * - 0x284
+     - \_\_le32
+     - s\_reserved[94]
      - Padding to the end of the block.
    * - 0x3FC
      - \_\_le32
@@ -603,6 +607,11 @@ following:
        the journal, JBD2 incompat feature
        (JBD2\_FEATURE\_INCOMPAT\_FAST\_COMMIT) gets
        set (COMPAT\_FAST\_COMMIT).
+   * - 0x1000
+     - Orphan file allocated. This is the special file for more efficient
+       tracking of unlinked but still open inodes. When there may be any
+       entries in the file, we additionally set proper rocompat feature
+       (RO\_COMPAT\_ORPHAN\_PRESENT).
 
 .. _super_incompat:
 
@@ -713,6 +722,10 @@ the following:
      - Filesystem tracks project quotas. (RO\_COMPAT\_PROJECT)
    * - 0x8000
      - Verity inodes may be present on the filesystem. (RO\_COMPAT\_VERITY)
+   * - 0x10000
+     - Indicates orphan file may have valid orphan entries and thus we need
+       to clean them up when mounting the filesystem
+       (RO\_COMPAT\_ORPHAN\_PRESENT).
 
 .. _super_def_hash:
 
-- 
2.26.2

Re: [PATCH 4/5] ext4: Orphan file documentation

[Theodore Ts'o]

On Wed, Aug 11, 2021 at 12:19:14PM +0200, Jan Kara wrote:
> Add documentation about the orphan file feature.
> 
> Signed-off-by: Jan Kara <jack@suse.cz>

Reviewed-by: Theodore Ts'o <tytso@mit.edu>

						- Ted

[PATCH 5/5] ext4: Improve scalability of ext4 orphan file handling

[Jan Kara]

Even though the length of the critical section when adding / removing
orphaned inodes was significantly reduced by using orphan file, the
contention of lock protecting orphan file still appears high in profiles
for truncate / unlink intensive workloads with high number of threads.

This patch makes handling of orphan file completely lockless. Also to
reduce conflicts between CPUs different CPUs start searching for empty
slot in orphan file in different blocks.

Performance comparison of locked orphan file handling, lockless orphan
file handling, and completely disabled orphan inode handling
from 80 CPU Xeon Server with 526 GB of RAM, filesystem located on
SAS SSD disk, average of 5 runs:

stress-orphan (microbenchmark truncating files byte-by-byte from N
processes in parallel)

Threads Time            Time            Time
        Orphan locked   Orphan lockless No orphan
  1       0.945600       0.939400        0.891200
  2       1.331800       1.246600        1.174400
  4       1.995000       1.780600        1.713200
  8       6.424200       4.900000        4.106000
 16      14.937600       8.516400        8.138000
 32      33.038200      24.565600       24.002200
 64      60.823600      39.844600       38.440200
128     122.941400      70.950400       69.315000

So we can see that with lockless orphan file handling, addition /
deletion of orphaned inodes got almost completely out of picture even
for a microbenchmark stressing it.

For reaim creat_clo workload on ramdisk there are also noticeable gains
(average of 5 runs):

Clients         Vanilla (ops/s)        Patched (ops/s)
creat_clo-1     14705.88 (   0.00%)    14354.07 *  -2.39%*
creat_clo-3     27108.43 (   0.00%)    28301.89 (   4.40%)
creat_clo-5     37406.48 (   0.00%)    45180.73 *  20.78%*
creat_clo-7     41338.58 (   0.00%)    54687.50 *  32.29%*
creat_clo-9     45226.13 (   0.00%)    62937.07 *  39.16%*
creat_clo-11    44000.00 (   0.00%)    65088.76 *  47.93%*
creat_clo-13    36516.85 (   0.00%)    68661.97 *  88.03%*
creat_clo-15    30864.20 (   0.00%)    69551.78 * 125.35%*
creat_clo-17    27478.45 (   0.00%)    67729.08 * 146.48%*
creat_clo-19    25000.00 (   0.00%)    61621.62 * 146.49%*
creat_clo-21    18772.35 (   0.00%)    63829.79 * 240.02%*
creat_clo-23    16698.94 (   0.00%)    61938.96 * 270.92%*
creat_clo-25    14973.05 (   0.00%)    56947.61 * 280.33%*
creat_clo-27    16436.69 (   0.00%)    65008.03 * 295.51%*
creat_clo-29    13949.01 (   0.00%)    69047.62 * 395.00%*
creat_clo-31    14283.52 (   0.00%)    67982.45 * 375.95%*

Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/ext4/ext4.h   |  3 +-
 fs/ext4/orphan.c | 72 ++++++++++++++++++++++++++++++++----------------
 2 files changed, 49 insertions(+), 26 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 456d6efe6613..5a2cbd0e5bd3 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1489,7 +1489,7 @@ static inline int ext4_inodes_per_orphan_block(struct super_block *sb)
 }
 
 struct ext4_orphan_block {
-	int ob_free_entries;	/* Number of free orphan entries in block */
+	atomic_t ob_free_entries;	/* Number of free orphan entries in block */
 	struct buffer_head *ob_bh;	/* Buffer for orphan block */
 };
 
@@ -1497,7 +1497,6 @@ struct ext4_orphan_block {
  * Info about orphan file.
  */
 struct ext4_orphan_info {
-	spinlock_t of_lock;
 	int of_blocks;			/* Number of orphan blocks in a file */
 	__u32 of_csum_seed;		/* Checksum seed for orphan file */
 	struct ext4_orphan_block *of_binfo;	/* Array with info about orphan
diff --git a/fs/ext4/orphan.c b/fs/ext4/orphan.c
index 019719c0ac12..18622ddeb41b 100644
--- a/fs/ext4/orphan.c
+++ b/fs/ext4/orphan.c
@@ -10,16 +10,31 @@
 
 static int ext4_orphan_file_add(handle_t *handle, struct inode *inode)
 {
-	int i, j;
+	int i, j, start;
 	struct ext4_orphan_info *oi = &EXT4_SB(inode->i_sb)->s_orphan_info;
 	int ret = 0;
+	bool found = false;
 	__le32 *bdata;
 	int inodes_per_ob = ext4_inodes_per_orphan_block(inode->i_sb);
+	int looped = 0;
 
-	spin_lock(&oi->of_lock);
-	for (i = 0; i < oi->of_blocks && !oi->of_binfo[i].ob_free_entries; i++);
-	if (i == oi->of_blocks) {
-		spin_unlock(&oi->of_lock);
+	/*
+	 * Find block with free orphan entry. Use CPU number for a naive hash
+	 * for a search start in the orphan file
+	 */
+	start = raw_smp_processor_id()*13 % oi->of_blocks;
+	i = start;
+	do {
+		if (atomic_dec_if_positive(&oi->of_binfo[i].ob_free_entries)
+		    >= 0) {
+			found = true;
+			break;
+		}
+		if (++i >= oi->of_blocks)
+			i = 0;
+	} while (i != start);
+
+	if (!found) {
 		/*
 		 * For now we don't grow or shrink orphan file. We just use
 		 * whatever was allocated at mke2fs time. The additional
@@ -28,28 +43,40 @@ static int ext4_orphan_file_add(handle_t *handle, struct inode *inode)
 		 */
 		return -ENOSPC;
 	}
-	oi->of_binfo[i].ob_free_entries--;
-	spin_unlock(&oi->of_lock);
 
-	/*
-	 * Get access to orphan block. We have dropped of_lock but since we
-	 * have decremented number of free entries we are guaranteed free entry
-	 * in our block.
-	 */
 	ret = ext4_journal_get_write_access(handle, inode->i_sb,
 				oi->of_binfo[i].ob_bh, EXT4_JTR_ORPHAN_FILE);
 	if (ret)
 		return ret;
 
 	bdata = (__le32 *)(oi->of_binfo[i].ob_bh->b_data);
-	spin_lock(&oi->of_lock);
 	/* Find empty slot in a block */
-	for (j = 0; j < inodes_per_ob && bdata[j]; j++);
-	BUG_ON(j == inodes_per_ob);
-	bdata[j] = cpu_to_le32(inode->i_ino);
+	j = 0;
+	do {
+		if (looped) {
+			/*
+			 * Did we walk through the block several times without
+			 * finding free entry? It is theoretically possible
+			 * if entries get constantly allocated and freed or
+			 * if the block is corrupted. Avoid indefinite looping
+			 * and bail. We'll use orphan list instead.
+			 */
+			if (looped > 3) {
+				atomic_inc(&oi->of_binfo[i].ob_free_entries);
+				return -ENOSPC;
+			}
+			cond_resched();
+		}
+		while (bdata[j]) {
+			if (++j >= inodes_per_ob) {
+				j = 0;
+				looped++;
+			}
+		}
+	} while (cmpxchg(&bdata[j], 0, cpu_to_le32(inode->i_ino)) != 0);
+
 	EXT4_I(inode)->i_orphan_idx = i * inodes_per_ob + j;
 	ext4_set_inode_state(inode, EXT4_STATE_ORPHAN_FILE);
-	spin_unlock(&oi->of_lock);
 
 	return ext4_handle_dirty_metadata(handle, NULL, oi->of_binfo[i].ob_bh);
 }
@@ -180,10 +207,8 @@ static int ext4_orphan_file_del(handle_t *handle, struct inode *inode)
 		goto out;
 
 	bdata = (__le32 *)(oi->of_binfo[blk].ob_bh->b_data);
-	spin_lock(&oi->of_lock);
 	bdata[off] = 0;
-	oi->of_binfo[blk].ob_free_entries++;
-	spin_unlock(&oi->of_lock);
+	atomic_inc(&oi->of_binfo[blk].ob_free_entries);
 	ret = ext4_handle_dirty_metadata(handle, NULL, oi->of_binfo[blk].ob_bh);
 out:
 	ext4_clear_inode_state(inode, EXT4_STATE_ORPHAN_FILE);
@@ -552,8 +577,6 @@ int ext4_init_orphan_info(struct super_block *sb)
 	struct ext4_orphan_block_tail *ot;
 	ino_t orphan_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_orphan_file_inum);
 
-	spin_lock_init(&oi->of_lock);
-
 	if (!ext4_has_feature_orphan_file(sb))
 		return 0;
 
@@ -597,7 +620,7 @@ int ext4_init_orphan_info(struct super_block *sb)
 		for (j = 0; j < inodes_per_ob; j++)
 			if (bdata[j] == 0)
 				free++;
-		oi->of_binfo[i].ob_free_entries = free;
+		atomic_set(&oi->of_binfo[i].ob_free_entries, free);
 	}
 	iput(inode);
 	return 0;
@@ -619,7 +642,8 @@ int ext4_orphan_file_empty(struct super_block *sb)
 	if (!ext4_has_feature_orphan_file(sb))
 		return 1;
 	for (i = 0; i < oi->of_blocks; i++)
-		if (oi->of_binfo[i].ob_free_entries != inodes_per_ob)
+		if (atomic_read(&oi->of_binfo[i].ob_free_entries) !=
+		    inodes_per_ob)
 			return 0;
 	return 1;
 }
-- 
2.26.2

Re: [PATCH 5/5] ext4: Improve scalability of ext4 orphan file handling

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 4374 bytes --]

Hi Jan,

I love your patch! Perhaps something to improve:

[auto build test WARNING on ext4/dev]
[also build test WARNING on ext3/for_next linus/master v5.14-rc5 next-20210811]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Jan-Kara/ext4-Speedup-orphan-file-handling/20210811-182113
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git dev
config: parisc-randconfig-s032-20210810 (attached as .config)
compiler: hppa-linux-gcc (GCC) 10.3.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.3-348-gf0e6938b-dirty
        # https://github.com/0day-ci/linux/commit/77029a42c6e037181b218cbf10a93561e664fb9e
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Jan-Kara/ext4-Speedup-orphan-file-handling/20210811-182113
        git checkout 77029a42c6e037181b218cbf10a93561e664fb9e
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-10.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=parisc SHELL=/bin/bash fs/ext4/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


sparse warnings: (new ones prefixed by >>)
>> fs/ext4/orphan.c:76:18: sparse: sparse: cast from restricted __le32
>> fs/ext4/orphan.c:76:18: sparse: sparse: cast from restricted __le32
>> fs/ext4/orphan.c:76:18: sparse: sparse: cast to restricted __le32

vim +76 fs/ext4/orphan.c

    10	
    11	static int ext4_orphan_file_add(handle_t *handle, struct inode *inode)
    12	{
    13		int i, j, start;
    14		struct ext4_orphan_info *oi = &EXT4_SB(inode->i_sb)->s_orphan_info;
    15		int ret = 0;
    16		bool found = false;
    17		__le32 *bdata;
    18		int inodes_per_ob = ext4_inodes_per_orphan_block(inode->i_sb);
    19		int looped = 0;
    20	
    21		/*
    22		 * Find block with free orphan entry. Use CPU number for a naive hash
    23		 * for a search start in the orphan file
    24		 */
    25		start = raw_smp_processor_id()*13 % oi->of_blocks;
    26		i = start;
    27		do {
    28			if (atomic_dec_if_positive(&oi->of_binfo[i].ob_free_entries)
    29			    >= 0) {
    30				found = true;
    31				break;
    32			}
    33			if (++i >= oi->of_blocks)
    34				i = 0;
    35		} while (i != start);
    36	
    37		if (!found) {
    38			/*
    39			 * For now we don't grow or shrink orphan file. We just use
    40			 * whatever was allocated at mke2fs time. The additional
    41			 * credits we would have to reserve for each orphan inode
    42			 * operation just don't seem worth it.
    43			 */
    44			return -ENOSPC;
    45		}
    46	
    47		ret = ext4_journal_get_write_access(handle, inode->i_sb,
    48					oi->of_binfo[i].ob_bh, EXT4_JTR_ORPHAN_FILE);
    49		if (ret)
    50			return ret;
    51	
    52		bdata = (__le32 *)(oi->of_binfo[i].ob_bh->b_data);
    53		/* Find empty slot in a block */
    54		j = 0;
    55		do {
    56			if (looped) {
    57				/*
    58				 * Did we walk through the block several times without
    59				 * finding free entry? It is theoretically possible
    60				 * if entries get constantly allocated and freed or
    61				 * if the block is corrupted. Avoid indefinite looping
    62				 * and bail. We'll use orphan list instead.
    63				 */
    64				if (looped > 3) {
    65					atomic_inc(&oi->of_binfo[i].ob_free_entries);
    66					return -ENOSPC;
    67				}
    68				cond_resched();
    69			}
    70			while (bdata[j]) {
    71				if (++j >= inodes_per_ob) {
    72					j = 0;
    73					looped++;
    74				}
    75			}
  > 76		} while (cmpxchg(&bdata[j], 0, cpu_to_le32(inode->i_ino)) != 0);
    77	
    78		EXT4_I(inode)->i_orphan_idx = i * inodes_per_ob + j;
    79		ext4_set_inode_state(inode, EXT4_STATE_ORPHAN_FILE);
    80	
    81		return ext4_handle_dirty_metadata(handle, NULL, oi->of_binfo[i].ob_bh);
    82	}
    83	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 35458 bytes --]

Re: [PATCH 5/5] ext4: Improve scalability of ext4 orphan file handling

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 4491 bytes --]

Hi Jan,

I love your patch! Perhaps something to improve:

[auto build test WARNING on ext4/dev]
[also build test WARNING on ext3/for_next linus/master v5.14-rc5 next-20210811]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Jan-Kara/ext4-Speedup-orphan-file-handling/20210811-182113
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git dev
config: parisc-randconfig-s032-20210810 (attached as .config)
compiler: hppa-linux-gcc (GCC) 10.3.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.3-348-gf0e6938b-dirty
        # https://github.com/0day-ci/linux/commit/77029a42c6e037181b218cbf10a93561e664fb9e
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Jan-Kara/ext4-Speedup-orphan-file-handling/20210811-182113
        git checkout 77029a42c6e037181b218cbf10a93561e664fb9e
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-10.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=parisc SHELL=/bin/bash fs/ext4/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


sparse warnings: (new ones prefixed by >>)
>> fs/ext4/orphan.c:76:18: sparse: sparse: cast from restricted __le32
>> fs/ext4/orphan.c:76:18: sparse: sparse: cast from restricted __le32
>> fs/ext4/orphan.c:76:18: sparse: sparse: cast to restricted __le32

vim +76 fs/ext4/orphan.c

    10	
    11	static int ext4_orphan_file_add(handle_t *handle, struct inode *inode)
    12	{
    13		int i, j, start;
    14		struct ext4_orphan_info *oi = &EXT4_SB(inode->i_sb)->s_orphan_info;
    15		int ret = 0;
    16		bool found = false;
    17		__le32 *bdata;
    18		int inodes_per_ob = ext4_inodes_per_orphan_block(inode->i_sb);
    19		int looped = 0;
    20	
    21		/*
    22		 * Find block with free orphan entry. Use CPU number for a naive hash
    23		 * for a search start in the orphan file
    24		 */
    25		start = raw_smp_processor_id()*13 % oi->of_blocks;
    26		i = start;
    27		do {
    28			if (atomic_dec_if_positive(&oi->of_binfo[i].ob_free_entries)
    29			    >= 0) {
    30				found = true;
    31				break;
    32			}
    33			if (++i >= oi->of_blocks)
    34				i = 0;
    35		} while (i != start);
    36	
    37		if (!found) {
    38			/*
    39			 * For now we don't grow or shrink orphan file. We just use
    40			 * whatever was allocated at mke2fs time. The additional
    41			 * credits we would have to reserve for each orphan inode
    42			 * operation just don't seem worth it.
    43			 */
    44			return -ENOSPC;
    45		}
    46	
    47		ret = ext4_journal_get_write_access(handle, inode->i_sb,
    48					oi->of_binfo[i].ob_bh, EXT4_JTR_ORPHAN_FILE);
    49		if (ret)
    50			return ret;
    51	
    52		bdata = (__le32 *)(oi->of_binfo[i].ob_bh->b_data);
    53		/* Find empty slot in a block */
    54		j = 0;
    55		do {
    56			if (looped) {
    57				/*
    58				 * Did we walk through the block several times without
    59				 * finding free entry? It is theoretically possible
    60				 * if entries get constantly allocated and freed or
    61				 * if the block is corrupted. Avoid indefinite looping
    62				 * and bail. We'll use orphan list instead.
    63				 */
    64				if (looped > 3) {
    65					atomic_inc(&oi->of_binfo[i].ob_free_entries);
    66					return -ENOSPC;
    67				}
    68				cond_resched();
    69			}
    70			while (bdata[j]) {
    71				if (++j >= inodes_per_ob) {
    72					j = 0;
    73					looped++;
    74				}
    75			}
  > 76		} while (cmpxchg(&bdata[j], 0, cpu_to_le32(inode->i_ino)) != 0);
    77	
    78		EXT4_I(inode)->i_orphan_idx = i * inodes_per_ob + j;
    79		ext4_set_inode_state(inode, EXT4_STATE_ORPHAN_FILE);
    80	
    81		return ext4_handle_dirty_metadata(handle, NULL, oi->of_binfo[i].ob_bh);
    82	}
    83	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 35458 bytes --]

Re: [PATCH 5/5] ext4: Improve scalability of ext4 orphan file handling

[Jan Kara]

On Thu 12-08-21 02:19:33, kernel test robot wrote:
> Hi Jan,
> 
> I love your patch! Perhaps something to improve:
> 
> [auto build test WARNING on ext4/dev]
> [also build test WARNING on ext3/for_next linus/master v5.14-rc5 next-20210811]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch]
> 
> url:    https://github.com/0day-ci/linux/commits/Jan-Kara/ext4-Speedup-orphan-file-handling/20210811-182113
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git dev
> config: parisc-randconfig-s032-20210810 (attached as .config)
> compiler: hppa-linux-gcc (GCC) 10.3.0
> reproduce:
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # apt-get install sparse
>         # sparse version: v0.6.3-348-gf0e6938b-dirty
>         # https://github.com/0day-ci/linux/commit/77029a42c6e037181b218cbf10a93561e664fb9e
>         git remote add linux-review https://github.com/0day-ci/linux
>         git fetch --no-tags linux-review Jan-Kara/ext4-Speedup-orphan-file-handling/20210811-182113
>         git checkout 77029a42c6e037181b218cbf10a93561e664fb9e
>         # save the attached .config to linux build tree
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-10.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=parisc SHELL=/bin/bash fs/ext4/
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> 
> 
> sparse warnings: (new ones prefixed by >>)
> >> fs/ext4/orphan.c:76:18: sparse: sparse: cast from restricted __le32
> >> fs/ext4/orphan.c:76:18: sparse: sparse: cast from restricted __le32
> >> fs/ext4/orphan.c:76:18: sparse: sparse: cast to restricted __le32
...
>   > 76		} while (cmpxchg(&bdata[j], 0, cpu_to_le32(inode->i_ino)) != 0);

Yeah, I didn't bother to convert 0 to little endian which is tripping up
sparse. I've now added explicit casts of 0 to __le32 so silence the
warning.

								Honza


-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

Re: [PATCH 5/5] ext4: Improve scalability of ext4 orphan file handling

[Jan Kara]

[-- Attachment #1: Type: text/plain, Size: 2252 bytes --]

On Thu 12-08-21 02:19:33, kernel test robot wrote:
> Hi Jan,
> 
> I love your patch! Perhaps something to improve:
> 
> [auto build test WARNING on ext4/dev]
> [also build test WARNING on ext3/for_next linus/master v5.14-rc5 next-20210811]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch]
> 
> url:    https://github.com/0day-ci/linux/commits/Jan-Kara/ext4-Speedup-orphan-file-handling/20210811-182113
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git dev
> config: parisc-randconfig-s032-20210810 (attached as .config)
> compiler: hppa-linux-gcc (GCC) 10.3.0
> reproduce:
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # apt-get install sparse
>         # sparse version: v0.6.3-348-gf0e6938b-dirty
>         # https://github.com/0day-ci/linux/commit/77029a42c6e037181b218cbf10a93561e664fb9e
>         git remote add linux-review https://github.com/0day-ci/linux
>         git fetch --no-tags linux-review Jan-Kara/ext4-Speedup-orphan-file-handling/20210811-182113
>         git checkout 77029a42c6e037181b218cbf10a93561e664fb9e
>         # save the attached .config to linux build tree
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-10.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=parisc SHELL=/bin/bash fs/ext4/
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> 
> 
> sparse warnings: (new ones prefixed by >>)
> >> fs/ext4/orphan.c:76:18: sparse: sparse: cast from restricted __le32
> >> fs/ext4/orphan.c:76:18: sparse: sparse: cast from restricted __le32
> >> fs/ext4/orphan.c:76:18: sparse: sparse: cast to restricted __le32
...
>   > 76		} while (cmpxchg(&bdata[j], 0, cpu_to_le32(inode->i_ino)) != 0);

Yeah, I didn't bother to convert 0 to little endian which is tripping up
sparse. I've now added explicit casts of 0 to __le32 so silence the
warning.

								Honza


-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

Re: [PATCH 5/5] ext4: Improve scalability of ext4 orphan file handling

[Theodore Ts'o]

On Wed, Aug 11, 2021 at 12:19:15PM +0200, Jan Kara wrote:
> diff --git a/fs/ext4/orphan.c b/fs/ext4/orphan.c
> index 019719c0ac12..18622ddeb41b 100644
> --- a/fs/ext4/orphan.c
> +++ b/fs/ext4/orphan.c
> @@ -28,28 +43,40 @@ static int ext4_orphan_file_add(handle_t *handle, struct inode *inode)
>  		 */
>  		return -ENOSPC;
>  	}
> -	oi->of_binfo[i].ob_free_entries--;
> -	spin_unlock(&oi->of_lock);
>  
> -	/*
> -	 * Get access to orphan block. We have dropped of_lock but since we
> -	 * have decremented number of free entries we are guaranteed free entry
> -	 * in our block.
> -	 */
>  	ret = ext4_journal_get_write_access(handle, inode->i_sb,
>  				oi->of_binfo[i].ob_bh, EXT4_JTR_ORPHAN_FILE);
>  	if (ret)
>  		return ret;

Shouldn't there be a call to:

		atomic_inc(&oi->of_binfo[i].ob_free_entries);

before we return, so the free_entry count stays consistent?

Otherwise, with the test-bot comments also addressed, you can add:

Reviewed-by: Theodore Ts'o <tytso@mit.edu>

Thanks,


       	  	     	 	    	  - Ted

[PATCH 0/5 v7] ext4: Speedup orphan file handling

[Jan Kara]

  Hello,

Here is the seventh version of my series to speed up orphan inode handling in
ext4. I've forgot to add a check that orphan file is not exposed in directory
hierarchy. The only change in this version is addition of that fix.

Orphan inode handling in ext4 is a bottleneck for workloads which heavily
excercise truncate / unlink of small files as they contend on global
s_orphan_mutex (when you have fast enough storage). This patch set implements
new way of handling orphan inodes - instead of using a linked list, we store
inode numbers of orphaned inodes in a file which is possible to implement in a
more scalable manner than linked list manipulations. See description of patch
3/5 for more details.

The patch set achieves significant gains both for a micro benchmark stressing
orphan inode handling (truncating file byte-by-byte, several threads in
parallel) and for reaim creat_clo workload. I'm happy for any review, thoughts,
ideas about the patches. I have also implemented full support in e2fsprogs
which I'll send separately.

								Honza

[1] https://lore.kernel.org/lkml/20210227120804.GB22871@xsang-OptiPlex-9020/

Changes since v6:
* Rebased on top of v5.14-rc6 + patches fixing exposure of hidden inodes in
  directory hierarchy
* Added check orphan file cannot be linked from directory hierarchy
* Get orphan file inode with EXT4_IGET_SPECIAL flag

Changes since v5:
* Added Reviewed-by tags from Ted
* Fixed up sparse warning spotted by 0-day
* Fixed error handling path in ext4_orphan_add() to not leak orphan entry

Changes since v4:
* Rebased on top of v5.14-rc5
* Updated commit message of patch 1/5
* Added Reviewed-by tags from Ted

Changes since v3:
* Added documentation about on-disk format changes
* Add physical block number into orphan block checksum
* Improve some sanity checks, handling of corrupted orphan file
* Improved some changelogs

Changes since v2:
* Updated some comments
* Rebased onto 5.13-rc5
* Change orphan file inode from a fixed inode number to inode number stored
  in the superblock

Changes since v1:
* orphan blocks have now magic numbers
* split out orphan handling to a separate source file
* some smaller updates according to review

Previous versions:
Link: http://lore.kernel.org/r/20210816091810.16994-1-jack@suse.cz # v6
Link: http://lore.kernel.org/r/20210811101006.2033-1-jack@suse.cz # v5
Link: https://lore.kernel.org/linux-ext4/20210712154009.9290-1-jack@suse.cz/ #v4
Link: https://lore.kernel.org/linux-ext4/20210616105655.5129-1-jack@suse.cz/ #v3
Link: https://lore.kernel.org/linux-ext4/1432293717-24010-1-git-send-email-jack@suse.cz/ #v2

[PATCH 3/5] ext4: Speedup ext4 orphan inode handling

[Jan Kara]

Ext4 orphan inode handling is a bottleneck for workloads which heavily
truncate / unlink small files since it contends on the global
s_orphan_mutex lock (and generally it's difficult to improve scalability
of the ondisk linked list of orphaned inodes).

This patch implements new way of handling orphan inodes. Instead of
linking orphaned inode into a linked list, we store it's inode number in
a new special file which we call "orphan file". Only if there's no more
space in the orphan file (too many inodes are currently orphaned) we
fall back to using old style linked list. Currently we protect
operations in the orphan file with a spinlock for simplicity but even in
this setting we can substantially reduce the length of the critical
section and thus speedup some workloads. In the next patch we improve
this by making orphan handling lockless.

Note that the change is backwards compatible when the filesystem is
clean - the existence of the orphan file is a compat feature, we set
another ro-compat feature indicating orphan file needs scanning for
orphaned inodes when mounting filesystem read-write. This ro-compat
feature gets cleared on unmount / remount read-only.

Some performance data from 80 CPU Xeon Server with 512 GB of RAM,
filesystem located on SSD, average of 5 runs:

stress-orphan (microbenchmark truncating files byte-by-byte from N
processes in parallel)

Threads Time            Time
        Vanilla         Patched
  1       1.057200        0.945600
  2       1.680400        1.331800
  4       2.547000        1.995000
  8       7.049400        6.424200
 16      14.827800       14.937600
 32      40.948200       33.038200
 64      87.787400       60.823600
128     206.504000      122.941400

So we can see significant wins all over the board.

Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/ext4/ext4.h   |  69 +++++++++-
 fs/ext4/inode.c  |   3 +-
 fs/ext4/orphan.c | 340 +++++++++++++++++++++++++++++++++++++++++------
 fs/ext4/super.c  |  34 ++++-
 4 files changed, 394 insertions(+), 52 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index b8194ea85fff..456d6efe6613 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1034,7 +1034,14 @@ struct ext4_inode_info {
 	 */
 	struct rw_semaphore xattr_sem;
 
-	struct list_head i_orphan;	/* unlinked but open inodes */
+	/*
+	 * Inodes with EXT4_STATE_ORPHAN_FILE use i_orphan_idx. Otherwise
+	 * i_orphan is used.
+	 */
+	union {
+		struct list_head i_orphan;	/* unlinked but open inodes */
+		unsigned int i_orphan_idx;	/* Index in orphan file */
+	};
 
 	/* Fast commit related info */
 
@@ -1428,7 +1435,8 @@ struct ext4_super_block {
 	__u8    s_last_error_errcode;
 	__le16  s_encoding;		/* Filename charset encoding */
 	__le16  s_encoding_flags;	/* Filename charset encoding flags */
-	__le32	s_reserved[95];		/* Padding to the end of the block */
+	__le32  s_orphan_file_inum;	/* Inode for tracking orphan inodes */
+	__le32	s_reserved[94];		/* Padding to the end of the block */
 	__le32	s_checksum;		/* crc32c(superblock) */
 };
 
@@ -1449,6 +1457,7 @@ struct ext4_super_block {
 
 /* Types of ext4 journal triggers */
 enum ext4_journal_trigger_type {
+	EXT4_JTR_ORPHAN_FILE,
 	EXT4_JTR_NONE	/* This must be the last entry for indexing to work! */
 };
 
@@ -1465,6 +1474,36 @@ static inline struct ext4_journal_trigger *EXT4_TRIGGER(
 	return container_of(trigger, struct ext4_journal_trigger, tr_triggers);
 }
 
+#define EXT4_ORPHAN_BLOCK_MAGIC 0x0b10ca04
+
+/* Structure at the tail of orphan block */
+struct ext4_orphan_block_tail {
+	__le32 ob_magic;
+	__le32 ob_checksum;
+};
+
+static inline int ext4_inodes_per_orphan_block(struct super_block *sb)
+{
+	return (sb->s_blocksize - sizeof(struct ext4_orphan_block_tail)) /
+			sizeof(u32);
+}
+
+struct ext4_orphan_block {
+	int ob_free_entries;	/* Number of free orphan entries in block */
+	struct buffer_head *ob_bh;	/* Buffer for orphan block */
+};
+
+/*
+ * Info about orphan file.
+ */
+struct ext4_orphan_info {
+	spinlock_t of_lock;
+	int of_blocks;			/* Number of orphan blocks in a file */
+	__u32 of_csum_seed;		/* Checksum seed for orphan file */
+	struct ext4_orphan_block *of_binfo;	/* Array with info about orphan
+						 * file blocks */
+};
+
 /*
  * fourth extended-fs super-block data in memory
  */
@@ -1519,9 +1558,11 @@ struct ext4_sb_info {
 
 	/* Journaling */
 	struct journal_s *s_journal;
-	struct list_head s_orphan;
-	struct mutex s_orphan_lock;
 	unsigned long s_ext4_flags;		/* Ext4 superblock flags */
+	struct mutex s_orphan_lock;	/* Protects on disk list changes */
+	struct list_head s_orphan;	/* List of orphaned inodes in on disk
+					   list */
+	struct ext4_orphan_info s_orphan_info;
 	unsigned long s_commit_interval;
 	u32 s_max_batch_time;
 	u32 s_min_batch_time;
@@ -1856,6 +1897,7 @@ enum {
 	EXT4_STATE_LUSTRE_EA_INODE,	/* Lustre-style ea_inode */
 	EXT4_STATE_VERITY_IN_PROGRESS,	/* building fs-verity Merkle tree */
 	EXT4_STATE_FC_COMMITTING,	/* Fast commit ongoing */
+	EXT4_STATE_ORPHAN_FILE,		/* Inode orphaned in orphan file */
 };
 
 #define EXT4_INODE_BIT_FNS(name, field, offset)				\
@@ -1957,6 +1999,7 @@ static inline bool ext4_verity_in_progress(struct inode *inode)
  */
 #define EXT4_FEATURE_COMPAT_FAST_COMMIT		0x0400
 #define EXT4_FEATURE_COMPAT_STABLE_INODES	0x0800
+#define EXT4_FEATURE_COMPAT_ORPHAN_FILE		0x1000	/* Orphan file exists */
 
 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
@@ -1977,6 +2020,8 @@ static inline bool ext4_verity_in_progress(struct inode *inode)
 #define EXT4_FEATURE_RO_COMPAT_READONLY		0x1000
 #define EXT4_FEATURE_RO_COMPAT_PROJECT		0x2000
 #define EXT4_FEATURE_RO_COMPAT_VERITY		0x8000
+#define EXT4_FEATURE_RO_COMPAT_ORPHAN_PRESENT	0x10000 /* Orphan file may be
+							   non-empty */
 
 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
@@ -2060,6 +2105,7 @@ EXT4_FEATURE_COMPAT_FUNCS(dir_index,		DIR_INDEX)
 EXT4_FEATURE_COMPAT_FUNCS(sparse_super2,	SPARSE_SUPER2)
 EXT4_FEATURE_COMPAT_FUNCS(fast_commit,		FAST_COMMIT)
 EXT4_FEATURE_COMPAT_FUNCS(stable_inodes,	STABLE_INODES)
+EXT4_FEATURE_COMPAT_FUNCS(orphan_file,		ORPHAN_FILE)
 
 EXT4_FEATURE_RO_COMPAT_FUNCS(sparse_super,	SPARSE_SUPER)
 EXT4_FEATURE_RO_COMPAT_FUNCS(large_file,	LARGE_FILE)
@@ -2074,6 +2120,7 @@ EXT4_FEATURE_RO_COMPAT_FUNCS(metadata_csum,	METADATA_CSUM)
 EXT4_FEATURE_RO_COMPAT_FUNCS(readonly,		READONLY)
 EXT4_FEATURE_RO_COMPAT_FUNCS(project,		PROJECT)
 EXT4_FEATURE_RO_COMPAT_FUNCS(verity,		VERITY)
+EXT4_FEATURE_RO_COMPAT_FUNCS(orphan_present,	ORPHAN_PRESENT)
 
 EXT4_FEATURE_INCOMPAT_FUNCS(compression,	COMPRESSION)
 EXT4_FEATURE_INCOMPAT_FUNCS(filetype,		FILETYPE)
@@ -2107,7 +2154,8 @@ EXT4_FEATURE_INCOMPAT_FUNCS(casefold,		CASEFOLD)
 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
 
-#define EXT4_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
+#define EXT4_FEATURE_COMPAT_SUPP	(EXT4_FEATURE_COMPAT_EXT_ATTR| \
+					 EXT4_FEATURE_COMPAT_ORPHAN_FILE)
 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
 					 EXT4_FEATURE_INCOMPAT_META_BG| \
@@ -2132,7 +2180,8 @@ EXT4_FEATURE_INCOMPAT_FUNCS(casefold,		CASEFOLD)
 					 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
 					 EXT4_FEATURE_RO_COMPAT_QUOTA |\
 					 EXT4_FEATURE_RO_COMPAT_PROJECT |\
-					 EXT4_FEATURE_RO_COMPAT_VERITY)
+					 EXT4_FEATURE_RO_COMPAT_VERITY |\
+					 EXT4_FEATURE_RO_COMPAT_ORPHAN_PRESENT)
 
 #define EXTN_FEATURE_FUNCS(ver) \
 static inline bool ext4_has_unknown_ext##ver##_compat_features(struct super_block *sb) \
@@ -2182,7 +2231,6 @@ static inline int ext4_forced_shutdown(struct ext4_sb_info *sbi)
 	return test_bit(EXT4_FLAGS_SHUTDOWN, &sbi->s_ext4_flags);
 }
 
-
 /*
  * Default values for user and/or group using reserved blocks
  */
@@ -3765,6 +3813,13 @@ extern int ext4_orphan_add(handle_t *, struct inode *);
 extern int ext4_orphan_del(handle_t *, struct inode *);
 extern void ext4_orphan_cleanup(struct super_block *sb,
 				struct ext4_super_block *es);
+extern void ext4_release_orphan_info(struct super_block *sb);
+extern int ext4_init_orphan_info(struct super_block *sb);
+extern int ext4_orphan_file_empty(struct super_block *sb);
+extern void ext4_orphan_file_block_trigger(
+				struct jbd2_buffer_trigger_type *triggers,
+				struct buffer_head *bh,
+				void *data, size_t size);
 
 /*
  * Add new method to test whether block and inode bitmaps are properly
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index d47a57f3d8de..8fc0dad9fa62 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4624,7 +4624,8 @@ struct inode *__ext4_iget(struct super_block *sb, unsigned long ino,
 	     ((ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO) ||
 	      ino == le32_to_cpu(es->s_usr_quota_inum) ||
 	      ino == le32_to_cpu(es->s_grp_quota_inum) ||
-	      ino == le32_to_cpu(es->s_prj_quota_inum))) ||
+	      ino == le32_to_cpu(es->s_prj_quota_inum) ||
+	      ino == le32_to_cpu(es->s_orphan_file_inum))) ||
 	    (ino < EXT4_ROOT_INO) ||
 	    (ino > le32_to_cpu(es->s_inodes_count))) {
 		if (flags & EXT4_IGET_HANDLE)
diff --git a/fs/ext4/orphan.c b/fs/ext4/orphan.c
index 1f2fa2ef53bd..ac928f60234a 100644
--- a/fs/ext4/orphan.c
+++ b/fs/ext4/orphan.c
@@ -8,6 +8,52 @@
 #include "ext4.h"
 #include "ext4_jbd2.h"
 
+static int ext4_orphan_file_add(handle_t *handle, struct inode *inode)
+{
+	int i, j;
+	struct ext4_orphan_info *oi = &EXT4_SB(inode->i_sb)->s_orphan_info;
+	int ret = 0;
+	__le32 *bdata;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(inode->i_sb);
+
+	spin_lock(&oi->of_lock);
+	for (i = 0; i < oi->of_blocks && !oi->of_binfo[i].ob_free_entries; i++);
+	if (i == oi->of_blocks) {
+		spin_unlock(&oi->of_lock);
+		/*
+		 * For now we don't grow or shrink orphan file. We just use
+		 * whatever was allocated at mke2fs time. The additional
+		 * credits we would have to reserve for each orphan inode
+		 * operation just don't seem worth it.
+		 */
+		return -ENOSPC;
+	}
+	oi->of_binfo[i].ob_free_entries--;
+	spin_unlock(&oi->of_lock);
+
+	/*
+	 * Get access to orphan block. We have dropped of_lock but since we
+	 * have decremented number of free entries we are guaranteed free entry
+	 * in our block.
+	 */
+	ret = ext4_journal_get_write_access(handle, inode->i_sb,
+				oi->of_binfo[i].ob_bh, EXT4_JTR_ORPHAN_FILE);
+	if (ret)
+		return ret;
+
+	bdata = (__le32 *)(oi->of_binfo[i].ob_bh->b_data);
+	spin_lock(&oi->of_lock);
+	/* Find empty slot in a block */
+	for (j = 0; j < inodes_per_ob && bdata[j]; j++);
+	BUG_ON(j == inodes_per_ob);
+	bdata[j] = cpu_to_le32(inode->i_ino);
+	EXT4_I(inode)->i_orphan_idx = i * inodes_per_ob + j;
+	ext4_set_inode_state(inode, EXT4_STATE_ORPHAN_FILE);
+	spin_unlock(&oi->of_lock);
+
+	return ext4_handle_dirty_metadata(handle, NULL, oi->of_binfo[i].ob_bh);
+}
+
 /*
  * ext4_orphan_add() links an unlinked or truncated inode into a list of
  * such inodes, starting at the superblock, in case we crash before the
@@ -34,10 +80,10 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode)
 	WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
 		     !inode_is_locked(inode));
 	/*
-	 * Exit early if inode already is on orphan list. This is a big speedup
-	 * since we don't have to contend on the global s_orphan_lock.
+	 * Inode orphaned in orphan file or in orphan list?
 	 */
-	if (!list_empty(&EXT4_I(inode)->i_orphan))
+	if (ext4_test_inode_state(inode, EXT4_STATE_ORPHAN_FILE) ||
+	    !list_empty(&EXT4_I(inode)->i_orphan))
 		return 0;
 
 	/*
@@ -49,6 +95,16 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode)
 	ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 		  S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
 
+	if (sbi->s_orphan_info.of_blocks) {
+		err = ext4_orphan_file_add(handle, inode);
+		/*
+		 * Fallback to normal orphan list of orphan file is
+		 * out of space
+		 */
+		if (err != -ENOSPC)
+			return err;
+	}
+
 	BUFFER_TRACE(sbi->s_sbh, "get_write_access");
 	err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,
 					    EXT4_JTR_NONE);
@@ -103,6 +159,39 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode)
 	return err;
 }
 
+static int ext4_orphan_file_del(handle_t *handle, struct inode *inode)
+{
+	struct ext4_orphan_info *oi = &EXT4_SB(inode->i_sb)->s_orphan_info;
+	__le32 *bdata;
+	int blk, off;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(inode->i_sb);
+	int ret = 0;
+
+	if (!handle)
+		goto out;
+	blk = EXT4_I(inode)->i_orphan_idx / inodes_per_ob;
+	off = EXT4_I(inode)->i_orphan_idx % inodes_per_ob;
+	if (WARN_ON_ONCE(blk >= oi->of_blocks))
+		goto out;
+
+	ret = ext4_journal_get_write_access(handle, inode->i_sb,
+				oi->of_binfo[blk].ob_bh, EXT4_JTR_ORPHAN_FILE);
+	if (ret)
+		goto out;
+
+	bdata = (__le32 *)(oi->of_binfo[blk].ob_bh->b_data);
+	spin_lock(&oi->of_lock);
+	bdata[off] = 0;
+	oi->of_binfo[blk].ob_free_entries++;
+	spin_unlock(&oi->of_lock);
+	ret = ext4_handle_dirty_metadata(handle, NULL, oi->of_binfo[blk].ob_bh);
+out:
+	ext4_clear_inode_state(inode, EXT4_STATE_ORPHAN_FILE);
+	INIT_LIST_HEAD(&EXT4_I(inode)->i_orphan);
+
+	return ret;
+}
+
 /*
  * ext4_orphan_del() removes an unlinked or truncated inode from the list
  * of such inodes stored on disk, because it is finally being cleaned up.
@@ -121,6 +210,9 @@ int ext4_orphan_del(handle_t *handle, struct inode *inode)
 
 	WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
 		     !inode_is_locked(inode));
+	if (ext4_test_inode_state(inode, EXT4_STATE_ORPHAN_FILE))
+		return ext4_orphan_file_del(handle, inode);
+
 	/* Do this quick check before taking global s_orphan_lock. */
 	if (list_empty(&ei->i_orphan))
 		return 0;
@@ -200,6 +292,46 @@ static int ext4_quota_on_mount(struct super_block *sb, int type)
 }
 #endif
 
+static void ext4_process_orphan(struct inode *inode,
+				int *nr_truncates, int *nr_orphans)
+{
+	struct super_block *sb = inode->i_sb;
+	int ret;
+
+	dquot_initialize(inode);
+	if (inode->i_nlink) {
+		if (test_opt(sb, DEBUG))
+			ext4_msg(sb, KERN_DEBUG,
+				"%s: truncating inode %lu to %lld bytes",
+				__func__, inode->i_ino, inode->i_size);
+		jbd_debug(2, "truncating inode %lu to %lld bytes\n",
+			  inode->i_ino, inode->i_size);
+		inode_lock(inode);
+		truncate_inode_pages(inode->i_mapping, inode->i_size);
+		ret = ext4_truncate(inode);
+		if (ret) {
+			/*
+			 * We need to clean up the in-core orphan list
+			 * manually if ext4_truncate() failed to get a
+			 * transaction handle.
+			 */
+			ext4_orphan_del(NULL, inode);
+			ext4_std_error(inode->i_sb, ret);
+		}
+		inode_unlock(inode);
+		(*nr_truncates)++;
+	} else {
+		if (test_opt(sb, DEBUG))
+			ext4_msg(sb, KERN_DEBUG,
+				"%s: deleting unreferenced inode %lu",
+				__func__, inode->i_ino);
+		jbd_debug(2, "deleting unreferenced inode %lu\n",
+			  inode->i_ino);
+		(*nr_orphans)++;
+	}
+	iput(inode);  /* The delete magic happens here! */
+}
+
 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
  * the superblock) which were deleted from all directories, but held open by
  * a process at the time of a crash.  We walk the list and try to delete these
@@ -220,12 +352,17 @@ static int ext4_quota_on_mount(struct super_block *sb, int type)
 void ext4_orphan_cleanup(struct super_block *sb, struct ext4_super_block *es)
 {
 	unsigned int s_flags = sb->s_flags;
-	int ret, nr_orphans = 0, nr_truncates = 0;
+	int nr_orphans = 0, nr_truncates = 0;
+	struct inode *inode;
+	int i, j;
 #ifdef CONFIG_QUOTA
 	int quota_update = 0;
-	int i;
 #endif
-	if (!es->s_last_orphan) {
+	__le32 *bdata;
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
+
+	if (!es->s_last_orphan && !oi->of_blocks) {
 		jbd_debug(4, "no orphan inodes to clean up\n");
 		return;
 	}
@@ -289,8 +426,6 @@ void ext4_orphan_cleanup(struct super_block *sb, struct ext4_super_block *es)
 #endif
 
 	while (es->s_last_orphan) {
-		struct inode *inode;
-
 		/*
 		 * We may have encountered an error during cleanup; if
 		 * so, skip the rest.
@@ -308,38 +443,21 @@ void ext4_orphan_cleanup(struct super_block *sb, struct ext4_super_block *es)
 		}
 
 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
-		dquot_initialize(inode);
-		if (inode->i_nlink) {
-			if (test_opt(sb, DEBUG))
-				ext4_msg(sb, KERN_DEBUG,
-					"%s: truncating inode %lu to %lld bytes",
-					__func__, inode->i_ino, inode->i_size);
-			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
-				  inode->i_ino, inode->i_size);
-			inode_lock(inode);
-			truncate_inode_pages(inode->i_mapping, inode->i_size);
-			ret = ext4_truncate(inode);
-			if (ret) {
-				/*
-				 * We need to clean up the in-core orphan list
-				 * manually if ext4_truncate() failed to get a
-				 * transaction handle.
-				 */
-				ext4_orphan_del(NULL, inode);
-				ext4_std_error(inode->i_sb, ret);
-			}
-			inode_unlock(inode);
-			nr_truncates++;
-		} else {
-			if (test_opt(sb, DEBUG))
-				ext4_msg(sb, KERN_DEBUG,
-					"%s: deleting unreferenced inode %lu",
-					__func__, inode->i_ino);
-			jbd_debug(2, "deleting unreferenced inode %lu\n",
-				  inode->i_ino);
-			nr_orphans++;
+		ext4_process_orphan(inode, &nr_truncates, &nr_orphans);
+	}
+
+	for (i = 0; i < oi->of_blocks; i++) {
+		bdata = (__le32 *)(oi->of_binfo[i].ob_bh->b_data);
+		for (j = 0; j < inodes_per_ob; j++) {
+			if (!bdata[j])
+				continue;
+			inode = ext4_orphan_get(sb, le32_to_cpu(bdata[j]));
+			if (IS_ERR(inode))
+				continue;
+			ext4_set_inode_state(inode, EXT4_STATE_ORPHAN_FILE);
+			EXT4_I(inode)->i_orphan_idx = i * inodes_per_ob + j;
+			ext4_process_orphan(inode, &nr_truncates, &nr_orphans);
 		}
-		iput(inode);  /* The delete magic happens here! */
 	}
 
 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
@@ -361,3 +479,147 @@ void ext4_orphan_cleanup(struct super_block *sb, struct ext4_super_block *es)
 #endif
 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
 }
+
+void ext4_release_orphan_info(struct super_block *sb)
+{
+	int i;
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+
+	if (!oi->of_blocks)
+		return;
+	for (i = 0; i < oi->of_blocks; i++)
+		brelse(oi->of_binfo[i].ob_bh);
+	kfree(oi->of_binfo);
+}
+
+static struct ext4_orphan_block_tail *ext4_orphan_block_tail(
+						struct super_block *sb,
+						struct buffer_head *bh)
+{
+	return (struct ext4_orphan_block_tail *)(bh->b_data + sb->s_blocksize -
+				sizeof(struct ext4_orphan_block_tail));
+}
+
+static int ext4_orphan_file_block_csum_verify(struct super_block *sb,
+					      struct buffer_head *bh)
+{
+	__u32 calculated;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+	struct ext4_orphan_block_tail *ot;
+	__le64 dsk_block_nr = cpu_to_le64(bh->b_blocknr);
+
+	if (!ext4_has_metadata_csum(sb))
+		return 1;
+
+	ot = ext4_orphan_block_tail(sb, bh);
+	calculated = ext4_chksum(EXT4_SB(sb), oi->of_csum_seed,
+				 (__u8 *)&dsk_block_nr, sizeof(dsk_block_nr));
+	calculated = ext4_chksum(EXT4_SB(sb), calculated, (__u8 *)bh->b_data,
+				 inodes_per_ob * sizeof(__u32));
+	return le32_to_cpu(ot->ob_checksum) == calculated;
+}
+
+/* This gets called only when checksumming is enabled */
+void ext4_orphan_file_block_trigger(struct jbd2_buffer_trigger_type *triggers,
+				    struct buffer_head *bh,
+				    void *data, size_t size)
+{
+	struct super_block *sb = EXT4_TRIGGER(triggers)->sb;
+	__u32 csum;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+	struct ext4_orphan_block_tail *ot;
+	__le64 dsk_block_nr = cpu_to_le64(bh->b_blocknr);
+
+	csum = ext4_chksum(EXT4_SB(sb), oi->of_csum_seed,
+			   (__u8 *)&dsk_block_nr, sizeof(dsk_block_nr));
+	csum = ext4_chksum(EXT4_SB(sb), csum, (__u8 *)data,
+			   inodes_per_ob * sizeof(__u32));
+	ot = ext4_orphan_block_tail(sb, bh);
+	ot->ob_checksum = cpu_to_le32(csum);
+}
+
+int ext4_init_orphan_info(struct super_block *sb)
+{
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+	struct inode *inode;
+	int i, j;
+	int ret;
+	int free;
+	__le32 *bdata;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
+	struct ext4_orphan_block_tail *ot;
+	ino_t orphan_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_orphan_file_inum);
+
+	spin_lock_init(&oi->of_lock);
+
+	if (!ext4_has_feature_orphan_file(sb))
+		return 0;
+
+	inode = ext4_iget(sb, orphan_ino, EXT4_IGET_SPECIAL);
+	if (IS_ERR(inode)) {
+		ext4_msg(sb, KERN_ERR, "get orphan inode failed");
+		return PTR_ERR(inode);
+	}
+	oi->of_blocks = inode->i_size >> sb->s_blocksize_bits;
+	oi->of_csum_seed = EXT4_I(inode)->i_csum_seed;
+	oi->of_binfo = kmalloc(oi->of_blocks*sizeof(struct ext4_orphan_block),
+			       GFP_KERNEL);
+	if (!oi->of_binfo) {
+		ret = -ENOMEM;
+		goto out_put;
+	}
+	for (i = 0; i < oi->of_blocks; i++) {
+		oi->of_binfo[i].ob_bh = ext4_bread(NULL, inode, i, 0);
+		if (IS_ERR(oi->of_binfo[i].ob_bh)) {
+			ret = PTR_ERR(oi->of_binfo[i].ob_bh);
+			goto out_free;
+		}
+		if (!oi->of_binfo[i].ob_bh) {
+			ret = -EIO;
+			goto out_free;
+		}
+		ot = ext4_orphan_block_tail(sb, oi->of_binfo[i].ob_bh);
+		if (le32_to_cpu(ot->ob_magic) != EXT4_ORPHAN_BLOCK_MAGIC) {
+			ext4_error(sb, "orphan file block %d: bad magic", i);
+			ret = -EIO;
+			goto out_free;
+		}
+		if (!ext4_orphan_file_block_csum_verify(sb,
+						oi->of_binfo[i].ob_bh)) {
+			ext4_error(sb, "orphan file block %d: bad checksum", i);
+			ret = -EIO;
+			goto out_free;
+		}
+		bdata = (__le32 *)(oi->of_binfo[i].ob_bh->b_data);
+		free = 0;
+		for (j = 0; j < inodes_per_ob; j++)
+			if (bdata[j] == 0)
+				free++;
+		oi->of_binfo[i].ob_free_entries = free;
+	}
+	iput(inode);
+	return 0;
+out_free:
+	for (i--; i >= 0; i--)
+		brelse(oi->of_binfo[i].ob_bh);
+	kfree(oi->of_binfo);
+out_put:
+	iput(inode);
+	return ret;
+}
+
+int ext4_orphan_file_empty(struct super_block *sb)
+{
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+	int i;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
+
+	if (!ext4_has_feature_orphan_file(sb))
+		return 1;
+	for (i = 0; i < oi->of_blocks; i++)
+		if (oi->of_binfo[i].ob_free_entries != inodes_per_ob)
+			return 0;
+	return 1;
+}
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index a7081d525faa..0715f5a5bb88 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1174,6 +1174,7 @@ static void ext4_put_super(struct super_block *sb)
 
 	flush_work(&sbi->s_error_work);
 	destroy_workqueue(sbi->rsv_conversion_wq);
+	ext4_release_orphan_info(sb);
 
 	/*
 	 * Unregister sysfs before destroying jbd2 journal.
@@ -1199,6 +1200,7 @@ static void ext4_put_super(struct super_block *sb)
 
 	if (!sb_rdonly(sb) && !aborted) {
 		ext4_clear_feature_journal_needs_recovery(sb);
+		ext4_clear_feature_orphan_present(sb);
 		es->s_state = cpu_to_le16(sbi->s_mount_state);
 	}
 	if (!sb_rdonly(sb))
@@ -2684,8 +2686,11 @@ static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
 	le16_add_cpu(&es->s_mnt_count, 1);
 	ext4_update_tstamp(es, s_mtime);
-	if (sbi->s_journal)
+	if (sbi->s_journal) {
 		ext4_set_feature_journal_needs_recovery(sb);
+		if (ext4_has_feature_orphan_file(sb))
+			ext4_set_feature_orphan_present(sb);
+	}
 
 	err = ext4_commit_super(sb);
 done:
@@ -3960,6 +3965,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		silent = 1;
 		goto cantfind_ext4;
 	}
+	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
+				ext4_orphan_file_block_trigger);
 
 	/* Load the checksum driver */
 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
@@ -4624,6 +4631,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_root = NULL;
 
 	needs_recovery = (es->s_last_orphan != 0 ||
+			  ext4_has_feature_orphan_present(sb) ||
 			  ext4_has_feature_journal_needs_recovery(sb));
 
 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
@@ -4914,12 +4922,15 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	if (err)
 		goto failed_mount7;
 
+	err = ext4_init_orphan_info(sb);
+	if (err)
+		goto failed_mount8;
 #ifdef CONFIG_QUOTA
 	/* Enable quota usage during mount. */
 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
 		err = ext4_enable_quotas(sb);
 		if (err)
-			goto failed_mount8;
+			goto failed_mount9;
 	}
 #endif  /* CONFIG_QUOTA */
 
@@ -4938,7 +4949,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		ext4_msg(sb, KERN_INFO, "recovery complete");
 		err = ext4_mark_recovery_complete(sb, es);
 		if (err)
-			goto failed_mount8;
+			goto failed_mount9;
 	}
 	if (EXT4_SB(sb)->s_journal) {
 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
@@ -4984,6 +4995,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
 	goto failed_mount;
 
+failed_mount9:
+	ext4_release_orphan_info(sb);
 failed_mount8:
 	ext4_unregister_sysfs(sb);
 	kobject_put(&sbi->s_kobj);
@@ -5494,8 +5507,15 @@ static int ext4_mark_recovery_complete(struct super_block *sb,
 	if (err < 0)
 		goto out;
 
-	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
+	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
+	    ext4_has_feature_orphan_present(sb))) {
+		if (!ext4_orphan_file_empty(sb)) {
+			ext4_error(sb, "Orphan file not empty on read-only fs.");
+			err = -EFSCORRUPTED;
+			goto out;
+		}
 		ext4_clear_feature_journal_needs_recovery(sb);
+		ext4_clear_feature_orphan_present(sb);
 		ext4_commit_super(sb);
 	}
 out:
@@ -5638,6 +5658,8 @@ static int ext4_freeze(struct super_block *sb)
 
 		/* Journal blocked and flushed, clear needs_recovery flag. */
 		ext4_clear_feature_journal_needs_recovery(sb);
+		if (ext4_orphan_file_empty(sb))
+			ext4_clear_feature_orphan_present(sb);
 	}
 
 	error = ext4_commit_super(sb);
@@ -5660,6 +5682,8 @@ static int ext4_unfreeze(struct super_block *sb)
 	if (EXT4_SB(sb)->s_journal) {
 		/* Reset the needs_recovery flag before the fs is unlocked. */
 		ext4_set_feature_journal_needs_recovery(sb);
+		if (ext4_has_feature_orphan_file(sb))
+			ext4_set_feature_orphan_present(sb);
 	}
 
 	ext4_commit_super(sb);
@@ -5863,7 +5887,7 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 			 * around from a previously readonly bdev mount,
 			 * require a full umount/remount for now.
 			 */
-			if (es->s_last_orphan) {
+			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
 				ext4_msg(sb, KERN_WARNING, "Couldn't "
 				       "remount RDWR because of unprocessed "
 				       "orphan inode list.  Please "
-- 
2.26.2

[PATCH 0/5 v6] ext4: Speedup orphan file handling

[Jan Kara]

  Hello,

Here is a fourth version of my series to speed up orphan inode handling in
ext4.

Orphan inode handling in ext4 is a bottleneck for workloads which heavily
excercise truncate / unlink of small files as they contend on global
s_orphan_mutex (when you have fast enough storage). This patch set implements
new way of handling orphan inodes - instead of using a linked list, we store
inode numbers of orphaned inodes in a file which is possible to implement in a
more scalable manner than linked list manipulations. See description of patch
3/5 for more details.

The patch set achieves significant gains both for a micro benchmark stressing
orphan inode handling (truncating file byte-by-byte, several threads in
parallel) and for reaim creat_clo workload. I'm happy for any review, thoughts,
ideas about the patches. I have also implemented full support in e2fsprogs
which I'll send separately.

								Honza

[1] https://lore.kernel.org/lkml/20210227120804.GB22871@xsang-OptiPlex-9020/

Changes since v5:
* Added Reviewed-by tags from Ted
* Fixed up sparse warning spotted by 0-day
* Fixed error handling path in ext4_orphan_add() to not leak orphan entry

Changes since v4:
* Rebased on top of v5.14-rc5
* Updated commit message of patch 1/5
* Added Reviewed-by tags from Ted

Changes since v3:
* Added documentation about on-disk format changes
* Add physical block number into orphan block checksum
* Improve some sanity checks, handling of corrupted orphan file
* Improved some changelogs

Changes since v2:
* Updated some comments
* Rebased onto 5.13-rc5
* Change orphan file inode from a fixed inode number to inode number stored
  in the superblock

Changes since v1:
* orphan blocks have now magic numbers
* split out orphan handling to a separate source file
* some smaller updates according to review

Previous versions:
Link: http://lore.kernel.org/r/20210811101006.2033-1-jack@suse.cz # v5
Link: https://lore.kernel.org/linux-ext4/20210712154009.9290-1-jack@suse.cz/ #v4
Link: https://lore.kernel.org/linux-ext4/20210616105655.5129-1-jack@suse.cz/ #v3
Link: https://lore.kernel.org/linux-ext4/1432293717-24010-1-git-send-email-jack@suse.cz/ #v2

[PATCH 3/5] ext4: Speedup ext4 orphan inode handling

[Jan Kara]

Ext4 orphan inode handling is a bottleneck for workloads which heavily
truncate / unlink small files since it contends on the global
s_orphan_mutex lock (and generally it's difficult to improve scalability
of the ondisk linked list of orphaned inodes).

This patch implements new way of handling orphan inodes. Instead of
linking orphaned inode into a linked list, we store it's inode number in
a new special file which we call "orphan file". Only if there's no more
space in the orphan file (too many inodes are currently orphaned) we
fall back to using old style linked list. Currently we protect
operations in the orphan file with a spinlock for simplicity but even in
this setting we can substantially reduce the length of the critical
section and thus speedup some workloads. In the next patch we improve
this by making orphan handling lockless.

Note that the change is backwards compatible when the filesystem is
clean - the existence of the orphan file is a compat feature, we set
another ro-compat feature indicating orphan file needs scanning for
orphaned inodes when mounting filesystem read-write. This ro-compat
feature gets cleared on unmount / remount read-only.

Some performance data from 80 CPU Xeon Server with 512 GB of RAM,
filesystem located on SSD, average of 5 runs:

stress-orphan (microbenchmark truncating files byte-by-byte from N
processes in parallel)

Threads Time            Time
        Vanilla         Patched
  1       1.057200        0.945600
  2       1.680400        1.331800
  4       2.547000        1.995000
  8       7.049400        6.424200
 16      14.827800       14.937600
 32      40.948200       33.038200
 64      87.787400       60.823600
128     206.504000      122.941400

So we can see significant wins all over the board.

Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/ext4/ext4.h   |  69 +++++++++-
 fs/ext4/orphan.c | 340 +++++++++++++++++++++++++++++++++++++++++------
 fs/ext4/super.c  |  34 ++++-
 3 files changed, 392 insertions(+), 51 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index b8194ea85fff..456d6efe6613 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1034,7 +1034,14 @@ struct ext4_inode_info {
 	 */
 	struct rw_semaphore xattr_sem;
 
-	struct list_head i_orphan;	/* unlinked but open inodes */
+	/*
+	 * Inodes with EXT4_STATE_ORPHAN_FILE use i_orphan_idx. Otherwise
+	 * i_orphan is used.
+	 */
+	union {
+		struct list_head i_orphan;	/* unlinked but open inodes */
+		unsigned int i_orphan_idx;	/* Index in orphan file */
+	};
 
 	/* Fast commit related info */
 
@@ -1428,7 +1435,8 @@ struct ext4_super_block {
 	__u8    s_last_error_errcode;
 	__le16  s_encoding;		/* Filename charset encoding */
 	__le16  s_encoding_flags;	/* Filename charset encoding flags */
-	__le32	s_reserved[95];		/* Padding to the end of the block */
+	__le32  s_orphan_file_inum;	/* Inode for tracking orphan inodes */
+	__le32	s_reserved[94];		/* Padding to the end of the block */
 	__le32	s_checksum;		/* crc32c(superblock) */
 };
 
@@ -1449,6 +1457,7 @@ struct ext4_super_block {
 
 /* Types of ext4 journal triggers */
 enum ext4_journal_trigger_type {
+	EXT4_JTR_ORPHAN_FILE,
 	EXT4_JTR_NONE	/* This must be the last entry for indexing to work! */
 };
 
@@ -1465,6 +1474,36 @@ static inline struct ext4_journal_trigger *EXT4_TRIGGER(
 	return container_of(trigger, struct ext4_journal_trigger, tr_triggers);
 }
 
+#define EXT4_ORPHAN_BLOCK_MAGIC 0x0b10ca04
+
+/* Structure at the tail of orphan block */
+struct ext4_orphan_block_tail {
+	__le32 ob_magic;
+	__le32 ob_checksum;
+};
+
+static inline int ext4_inodes_per_orphan_block(struct super_block *sb)
+{
+	return (sb->s_blocksize - sizeof(struct ext4_orphan_block_tail)) /
+			sizeof(u32);
+}
+
+struct ext4_orphan_block {
+	int ob_free_entries;	/* Number of free orphan entries in block */
+	struct buffer_head *ob_bh;	/* Buffer for orphan block */
+};
+
+/*
+ * Info about orphan file.
+ */
+struct ext4_orphan_info {
+	spinlock_t of_lock;
+	int of_blocks;			/* Number of orphan blocks in a file */
+	__u32 of_csum_seed;		/* Checksum seed for orphan file */
+	struct ext4_orphan_block *of_binfo;	/* Array with info about orphan
+						 * file blocks */
+};
+
 /*
  * fourth extended-fs super-block data in memory
  */
@@ -1519,9 +1558,11 @@ struct ext4_sb_info {
 
 	/* Journaling */
 	struct journal_s *s_journal;
-	struct list_head s_orphan;
-	struct mutex s_orphan_lock;
 	unsigned long s_ext4_flags;		/* Ext4 superblock flags */
+	struct mutex s_orphan_lock;	/* Protects on disk list changes */
+	struct list_head s_orphan;	/* List of orphaned inodes in on disk
+					   list */
+	struct ext4_orphan_info s_orphan_info;
 	unsigned long s_commit_interval;
 	u32 s_max_batch_time;
 	u32 s_min_batch_time;
@@ -1856,6 +1897,7 @@ enum {
 	EXT4_STATE_LUSTRE_EA_INODE,	/* Lustre-style ea_inode */
 	EXT4_STATE_VERITY_IN_PROGRESS,	/* building fs-verity Merkle tree */
 	EXT4_STATE_FC_COMMITTING,	/* Fast commit ongoing */
+	EXT4_STATE_ORPHAN_FILE,		/* Inode orphaned in orphan file */
 };
 
 #define EXT4_INODE_BIT_FNS(name, field, offset)				\
@@ -1957,6 +1999,7 @@ static inline bool ext4_verity_in_progress(struct inode *inode)
  */
 #define EXT4_FEATURE_COMPAT_FAST_COMMIT		0x0400
 #define EXT4_FEATURE_COMPAT_STABLE_INODES	0x0800
+#define EXT4_FEATURE_COMPAT_ORPHAN_FILE		0x1000	/* Orphan file exists */
 
 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
@@ -1977,6 +2020,8 @@ static inline bool ext4_verity_in_progress(struct inode *inode)
 #define EXT4_FEATURE_RO_COMPAT_READONLY		0x1000
 #define EXT4_FEATURE_RO_COMPAT_PROJECT		0x2000
 #define EXT4_FEATURE_RO_COMPAT_VERITY		0x8000
+#define EXT4_FEATURE_RO_COMPAT_ORPHAN_PRESENT	0x10000 /* Orphan file may be
+							   non-empty */
 
 #define EXT4_FEATURE_INCOMPAT_COMPRESSION	0x0001
 #define EXT4_FEATURE_INCOMPAT_FILETYPE		0x0002
@@ -2060,6 +2105,7 @@ EXT4_FEATURE_COMPAT_FUNCS(dir_index,		DIR_INDEX)
 EXT4_FEATURE_COMPAT_FUNCS(sparse_super2,	SPARSE_SUPER2)
 EXT4_FEATURE_COMPAT_FUNCS(fast_commit,		FAST_COMMIT)
 EXT4_FEATURE_COMPAT_FUNCS(stable_inodes,	STABLE_INODES)
+EXT4_FEATURE_COMPAT_FUNCS(orphan_file,		ORPHAN_FILE)
 
 EXT4_FEATURE_RO_COMPAT_FUNCS(sparse_super,	SPARSE_SUPER)
 EXT4_FEATURE_RO_COMPAT_FUNCS(large_file,	LARGE_FILE)
@@ -2074,6 +2120,7 @@ EXT4_FEATURE_RO_COMPAT_FUNCS(metadata_csum,	METADATA_CSUM)
 EXT4_FEATURE_RO_COMPAT_FUNCS(readonly,		READONLY)
 EXT4_FEATURE_RO_COMPAT_FUNCS(project,		PROJECT)
 EXT4_FEATURE_RO_COMPAT_FUNCS(verity,		VERITY)
+EXT4_FEATURE_RO_COMPAT_FUNCS(orphan_present,	ORPHAN_PRESENT)
 
 EXT4_FEATURE_INCOMPAT_FUNCS(compression,	COMPRESSION)
 EXT4_FEATURE_INCOMPAT_FUNCS(filetype,		FILETYPE)
@@ -2107,7 +2154,8 @@ EXT4_FEATURE_INCOMPAT_FUNCS(casefold,		CASEFOLD)
 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
 
-#define EXT4_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
+#define EXT4_FEATURE_COMPAT_SUPP	(EXT4_FEATURE_COMPAT_EXT_ATTR| \
+					 EXT4_FEATURE_COMPAT_ORPHAN_FILE)
 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
 					 EXT4_FEATURE_INCOMPAT_META_BG| \
@@ -2132,7 +2180,8 @@ EXT4_FEATURE_INCOMPAT_FUNCS(casefold,		CASEFOLD)
 					 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
 					 EXT4_FEATURE_RO_COMPAT_QUOTA |\
 					 EXT4_FEATURE_RO_COMPAT_PROJECT |\
-					 EXT4_FEATURE_RO_COMPAT_VERITY)
+					 EXT4_FEATURE_RO_COMPAT_VERITY |\
+					 EXT4_FEATURE_RO_COMPAT_ORPHAN_PRESENT)
 
 #define EXTN_FEATURE_FUNCS(ver) \
 static inline bool ext4_has_unknown_ext##ver##_compat_features(struct super_block *sb) \
@@ -2182,7 +2231,6 @@ static inline int ext4_forced_shutdown(struct ext4_sb_info *sbi)
 	return test_bit(EXT4_FLAGS_SHUTDOWN, &sbi->s_ext4_flags);
 }
 
-
 /*
  * Default values for user and/or group using reserved blocks
  */
@@ -3765,6 +3813,13 @@ extern int ext4_orphan_add(handle_t *, struct inode *);
 extern int ext4_orphan_del(handle_t *, struct inode *);
 extern void ext4_orphan_cleanup(struct super_block *sb,
 				struct ext4_super_block *es);
+extern void ext4_release_orphan_info(struct super_block *sb);
+extern int ext4_init_orphan_info(struct super_block *sb);
+extern int ext4_orphan_file_empty(struct super_block *sb);
+extern void ext4_orphan_file_block_trigger(
+				struct jbd2_buffer_trigger_type *triggers,
+				struct buffer_head *bh,
+				void *data, size_t size);
 
 /*
  * Add new method to test whether block and inode bitmaps are properly
diff --git a/fs/ext4/orphan.c b/fs/ext4/orphan.c
index 1f2fa2ef53bd..019719c0ac12 100644
--- a/fs/ext4/orphan.c
+++ b/fs/ext4/orphan.c
@@ -8,6 +8,52 @@
 #include "ext4.h"
 #include "ext4_jbd2.h"
 
+static int ext4_orphan_file_add(handle_t *handle, struct inode *inode)
+{
+	int i, j;
+	struct ext4_orphan_info *oi = &EXT4_SB(inode->i_sb)->s_orphan_info;
+	int ret = 0;
+	__le32 *bdata;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(inode->i_sb);
+
+	spin_lock(&oi->of_lock);
+	for (i = 0; i < oi->of_blocks && !oi->of_binfo[i].ob_free_entries; i++);
+	if (i == oi->of_blocks) {
+		spin_unlock(&oi->of_lock);
+		/*
+		 * For now we don't grow or shrink orphan file. We just use
+		 * whatever was allocated at mke2fs time. The additional
+		 * credits we would have to reserve for each orphan inode
+		 * operation just don't seem worth it.
+		 */
+		return -ENOSPC;
+	}
+	oi->of_binfo[i].ob_free_entries--;
+	spin_unlock(&oi->of_lock);
+
+	/*
+	 * Get access to orphan block. We have dropped of_lock but since we
+	 * have decremented number of free entries we are guaranteed free entry
+	 * in our block.
+	 */
+	ret = ext4_journal_get_write_access(handle, inode->i_sb,
+				oi->of_binfo[i].ob_bh, EXT4_JTR_ORPHAN_FILE);
+	if (ret)
+		return ret;
+
+	bdata = (__le32 *)(oi->of_binfo[i].ob_bh->b_data);
+	spin_lock(&oi->of_lock);
+	/* Find empty slot in a block */
+	for (j = 0; j < inodes_per_ob && bdata[j]; j++);
+	BUG_ON(j == inodes_per_ob);
+	bdata[j] = cpu_to_le32(inode->i_ino);
+	EXT4_I(inode)->i_orphan_idx = i * inodes_per_ob + j;
+	ext4_set_inode_state(inode, EXT4_STATE_ORPHAN_FILE);
+	spin_unlock(&oi->of_lock);
+
+	return ext4_handle_dirty_metadata(handle, NULL, oi->of_binfo[i].ob_bh);
+}
+
 /*
  * ext4_orphan_add() links an unlinked or truncated inode into a list of
  * such inodes, starting at the superblock, in case we crash before the
@@ -34,10 +80,10 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode)
 	WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
 		     !inode_is_locked(inode));
 	/*
-	 * Exit early if inode already is on orphan list. This is a big speedup
-	 * since we don't have to contend on the global s_orphan_lock.
+	 * Inode orphaned in orphan file or in orphan list?
 	 */
-	if (!list_empty(&EXT4_I(inode)->i_orphan))
+	if (ext4_test_inode_state(inode, EXT4_STATE_ORPHAN_FILE) ||
+	    !list_empty(&EXT4_I(inode)->i_orphan))
 		return 0;
 
 	/*
@@ -49,6 +95,16 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode)
 	ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 		  S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
 
+	if (sbi->s_orphan_info.of_blocks) {
+		err = ext4_orphan_file_add(handle, inode);
+		/*
+		 * Fallback to normal orphan list of orphan file is
+		 * out of space
+		 */
+		if (err != -ENOSPC)
+			return err;
+	}
+
 	BUFFER_TRACE(sbi->s_sbh, "get_write_access");
 	err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,
 					    EXT4_JTR_NONE);
@@ -103,6 +159,39 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode)
 	return err;
 }
 
+static int ext4_orphan_file_del(handle_t *handle, struct inode *inode)
+{
+	struct ext4_orphan_info *oi = &EXT4_SB(inode->i_sb)->s_orphan_info;
+	__le32 *bdata;
+	int blk, off;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(inode->i_sb);
+	int ret = 0;
+
+	if (!handle)
+		goto out;
+	blk = EXT4_I(inode)->i_orphan_idx / inodes_per_ob;
+	off = EXT4_I(inode)->i_orphan_idx % inodes_per_ob;
+	if (WARN_ON_ONCE(blk >= oi->of_blocks))
+		goto out;
+
+	ret = ext4_journal_get_write_access(handle, inode->i_sb,
+				oi->of_binfo[blk].ob_bh, EXT4_JTR_ORPHAN_FILE);
+	if (ret)
+		goto out;
+
+	bdata = (__le32 *)(oi->of_binfo[blk].ob_bh->b_data);
+	spin_lock(&oi->of_lock);
+	bdata[off] = 0;
+	oi->of_binfo[blk].ob_free_entries++;
+	spin_unlock(&oi->of_lock);
+	ret = ext4_handle_dirty_metadata(handle, NULL, oi->of_binfo[blk].ob_bh);
+out:
+	ext4_clear_inode_state(inode, EXT4_STATE_ORPHAN_FILE);
+	INIT_LIST_HEAD(&EXT4_I(inode)->i_orphan);
+
+	return ret;
+}
+
 /*
  * ext4_orphan_del() removes an unlinked or truncated inode from the list
  * of such inodes stored on disk, because it is finally being cleaned up.
@@ -121,6 +210,9 @@ int ext4_orphan_del(handle_t *handle, struct inode *inode)
 
 	WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
 		     !inode_is_locked(inode));
+	if (ext4_test_inode_state(inode, EXT4_STATE_ORPHAN_FILE))
+		return ext4_orphan_file_del(handle, inode);
+
 	/* Do this quick check before taking global s_orphan_lock. */
 	if (list_empty(&ei->i_orphan))
 		return 0;
@@ -200,6 +292,46 @@ static int ext4_quota_on_mount(struct super_block *sb, int type)
 }
 #endif
 
+static void ext4_process_orphan(struct inode *inode,
+				int *nr_truncates, int *nr_orphans)
+{
+	struct super_block *sb = inode->i_sb;
+	int ret;
+
+	dquot_initialize(inode);
+	if (inode->i_nlink) {
+		if (test_opt(sb, DEBUG))
+			ext4_msg(sb, KERN_DEBUG,
+				"%s: truncating inode %lu to %lld bytes",
+				__func__, inode->i_ino, inode->i_size);
+		jbd_debug(2, "truncating inode %lu to %lld bytes\n",
+			  inode->i_ino, inode->i_size);
+		inode_lock(inode);
+		truncate_inode_pages(inode->i_mapping, inode->i_size);
+		ret = ext4_truncate(inode);
+		if (ret) {
+			/*
+			 * We need to clean up the in-core orphan list
+			 * manually if ext4_truncate() failed to get a
+			 * transaction handle.
+			 */
+			ext4_orphan_del(NULL, inode);
+			ext4_std_error(inode->i_sb, ret);
+		}
+		inode_unlock(inode);
+		(*nr_truncates)++;
+	} else {
+		if (test_opt(sb, DEBUG))
+			ext4_msg(sb, KERN_DEBUG,
+				"%s: deleting unreferenced inode %lu",
+				__func__, inode->i_ino);
+		jbd_debug(2, "deleting unreferenced inode %lu\n",
+			  inode->i_ino);
+		(*nr_orphans)++;
+	}
+	iput(inode);  /* The delete magic happens here! */
+}
+
 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
  * the superblock) which were deleted from all directories, but held open by
  * a process at the time of a crash.  We walk the list and try to delete these
@@ -220,12 +352,17 @@ static int ext4_quota_on_mount(struct super_block *sb, int type)
 void ext4_orphan_cleanup(struct super_block *sb, struct ext4_super_block *es)
 {
 	unsigned int s_flags = sb->s_flags;
-	int ret, nr_orphans = 0, nr_truncates = 0;
+	int nr_orphans = 0, nr_truncates = 0;
+	struct inode *inode;
+	int i, j;
 #ifdef CONFIG_QUOTA
 	int quota_update = 0;
-	int i;
 #endif
-	if (!es->s_last_orphan) {
+	__le32 *bdata;
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
+
+	if (!es->s_last_orphan && !oi->of_blocks) {
 		jbd_debug(4, "no orphan inodes to clean up\n");
 		return;
 	}
@@ -289,8 +426,6 @@ void ext4_orphan_cleanup(struct super_block *sb, struct ext4_super_block *es)
 #endif
 
 	while (es->s_last_orphan) {
-		struct inode *inode;
-
 		/*
 		 * We may have encountered an error during cleanup; if
 		 * so, skip the rest.
@@ -308,38 +443,21 @@ void ext4_orphan_cleanup(struct super_block *sb, struct ext4_super_block *es)
 		}
 
 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
-		dquot_initialize(inode);
-		if (inode->i_nlink) {
-			if (test_opt(sb, DEBUG))
-				ext4_msg(sb, KERN_DEBUG,
-					"%s: truncating inode %lu to %lld bytes",
-					__func__, inode->i_ino, inode->i_size);
-			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
-				  inode->i_ino, inode->i_size);
-			inode_lock(inode);
-			truncate_inode_pages(inode->i_mapping, inode->i_size);
-			ret = ext4_truncate(inode);
-			if (ret) {
-				/*
-				 * We need to clean up the in-core orphan list
-				 * manually if ext4_truncate() failed to get a
-				 * transaction handle.
-				 */
-				ext4_orphan_del(NULL, inode);
-				ext4_std_error(inode->i_sb, ret);
-			}
-			inode_unlock(inode);
-			nr_truncates++;
-		} else {
-			if (test_opt(sb, DEBUG))
-				ext4_msg(sb, KERN_DEBUG,
-					"%s: deleting unreferenced inode %lu",
-					__func__, inode->i_ino);
-			jbd_debug(2, "deleting unreferenced inode %lu\n",
-				  inode->i_ino);
-			nr_orphans++;
+		ext4_process_orphan(inode, &nr_truncates, &nr_orphans);
+	}
+
+	for (i = 0; i < oi->of_blocks; i++) {
+		bdata = (__le32 *)(oi->of_binfo[i].ob_bh->b_data);
+		for (j = 0; j < inodes_per_ob; j++) {
+			if (!bdata[j])
+				continue;
+			inode = ext4_orphan_get(sb, le32_to_cpu(bdata[j]));
+			if (IS_ERR(inode))
+				continue;
+			ext4_set_inode_state(inode, EXT4_STATE_ORPHAN_FILE);
+			EXT4_I(inode)->i_orphan_idx = i * inodes_per_ob + j;
+			ext4_process_orphan(inode, &nr_truncates, &nr_orphans);
 		}
-		iput(inode);  /* The delete magic happens here! */
 	}
 
 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
@@ -361,3 +479,147 @@ void ext4_orphan_cleanup(struct super_block *sb, struct ext4_super_block *es)
 #endif
 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
 }
+
+void ext4_release_orphan_info(struct super_block *sb)
+{
+	int i;
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+
+	if (!oi->of_blocks)
+		return;
+	for (i = 0; i < oi->of_blocks; i++)
+		brelse(oi->of_binfo[i].ob_bh);
+	kfree(oi->of_binfo);
+}
+
+static struct ext4_orphan_block_tail *ext4_orphan_block_tail(
+						struct super_block *sb,
+						struct buffer_head *bh)
+{
+	return (struct ext4_orphan_block_tail *)(bh->b_data + sb->s_blocksize -
+				sizeof(struct ext4_orphan_block_tail));
+}
+
+static int ext4_orphan_file_block_csum_verify(struct super_block *sb,
+					      struct buffer_head *bh)
+{
+	__u32 calculated;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+	struct ext4_orphan_block_tail *ot;
+	__le64 dsk_block_nr = cpu_to_le64(bh->b_blocknr);
+
+	if (!ext4_has_metadata_csum(sb))
+		return 1;
+
+	ot = ext4_orphan_block_tail(sb, bh);
+	calculated = ext4_chksum(EXT4_SB(sb), oi->of_csum_seed,
+				 (__u8 *)&dsk_block_nr, sizeof(dsk_block_nr));
+	calculated = ext4_chksum(EXT4_SB(sb), calculated, (__u8 *)bh->b_data,
+				 inodes_per_ob * sizeof(__u32));
+	return le32_to_cpu(ot->ob_checksum) == calculated;
+}
+
+/* This gets called only when checksumming is enabled */
+void ext4_orphan_file_block_trigger(struct jbd2_buffer_trigger_type *triggers,
+				    struct buffer_head *bh,
+				    void *data, size_t size)
+{
+	struct super_block *sb = EXT4_TRIGGER(triggers)->sb;
+	__u32 csum;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+	struct ext4_orphan_block_tail *ot;
+	__le64 dsk_block_nr = cpu_to_le64(bh->b_blocknr);
+
+	csum = ext4_chksum(EXT4_SB(sb), oi->of_csum_seed,
+			   (__u8 *)&dsk_block_nr, sizeof(dsk_block_nr));
+	csum = ext4_chksum(EXT4_SB(sb), csum, (__u8 *)data,
+			   inodes_per_ob * sizeof(__u32));
+	ot = ext4_orphan_block_tail(sb, bh);
+	ot->ob_checksum = cpu_to_le32(csum);
+}
+
+int ext4_init_orphan_info(struct super_block *sb)
+{
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+	struct inode *inode;
+	int i, j;
+	int ret;
+	int free;
+	__le32 *bdata;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
+	struct ext4_orphan_block_tail *ot;
+	ino_t orphan_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_orphan_file_inum);
+
+	spin_lock_init(&oi->of_lock);
+
+	if (!ext4_has_feature_orphan_file(sb))
+		return 0;
+
+	inode = ext4_iget(sb, orphan_ino, EXT4_IGET_NORMAL);
+	if (IS_ERR(inode)) {
+		ext4_msg(sb, KERN_ERR, "get orphan inode failed");
+		return PTR_ERR(inode);
+	}
+	oi->of_blocks = inode->i_size >> sb->s_blocksize_bits;
+	oi->of_csum_seed = EXT4_I(inode)->i_csum_seed;
+	oi->of_binfo = kmalloc(oi->of_blocks*sizeof(struct ext4_orphan_block),
+			       GFP_KERNEL);
+	if (!oi->of_binfo) {
+		ret = -ENOMEM;
+		goto out_put;
+	}
+	for (i = 0; i < oi->of_blocks; i++) {
+		oi->of_binfo[i].ob_bh = ext4_bread(NULL, inode, i, 0);
+		if (IS_ERR(oi->of_binfo[i].ob_bh)) {
+			ret = PTR_ERR(oi->of_binfo[i].ob_bh);
+			goto out_free;
+		}
+		if (!oi->of_binfo[i].ob_bh) {
+			ret = -EIO;
+			goto out_free;
+		}
+		ot = ext4_orphan_block_tail(sb, oi->of_binfo[i].ob_bh);
+		if (le32_to_cpu(ot->ob_magic) != EXT4_ORPHAN_BLOCK_MAGIC) {
+			ext4_error(sb, "orphan file block %d: bad magic", i);
+			ret = -EIO;
+			goto out_free;
+		}
+		if (!ext4_orphan_file_block_csum_verify(sb,
+						oi->of_binfo[i].ob_bh)) {
+			ext4_error(sb, "orphan file block %d: bad checksum", i);
+			ret = -EIO;
+			goto out_free;
+		}
+		bdata = (__le32 *)(oi->of_binfo[i].ob_bh->b_data);
+		free = 0;
+		for (j = 0; j < inodes_per_ob; j++)
+			if (bdata[j] == 0)
+				free++;
+		oi->of_binfo[i].ob_free_entries = free;
+	}
+	iput(inode);
+	return 0;
+out_free:
+	for (i--; i >= 0; i--)
+		brelse(oi->of_binfo[i].ob_bh);
+	kfree(oi->of_binfo);
+out_put:
+	iput(inode);
+	return ret;
+}
+
+int ext4_orphan_file_empty(struct super_block *sb)
+{
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+	int i;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
+
+	if (!ext4_has_feature_orphan_file(sb))
+		return 1;
+	for (i = 0; i < oi->of_blocks; i++)
+		if (oi->of_binfo[i].ob_free_entries != inodes_per_ob)
+			return 0;
+	return 1;
+}
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index a7081d525faa..0715f5a5bb88 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1174,6 +1174,7 @@ static void ext4_put_super(struct super_block *sb)
 
 	flush_work(&sbi->s_error_work);
 	destroy_workqueue(sbi->rsv_conversion_wq);
+	ext4_release_orphan_info(sb);
 
 	/*
 	 * Unregister sysfs before destroying jbd2 journal.
@@ -1199,6 +1200,7 @@ static void ext4_put_super(struct super_block *sb)
 
 	if (!sb_rdonly(sb) && !aborted) {
 		ext4_clear_feature_journal_needs_recovery(sb);
+		ext4_clear_feature_orphan_present(sb);
 		es->s_state = cpu_to_le16(sbi->s_mount_state);
 	}
 	if (!sb_rdonly(sb))
@@ -2684,8 +2686,11 @@ static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
 	le16_add_cpu(&es->s_mnt_count, 1);
 	ext4_update_tstamp(es, s_mtime);
-	if (sbi->s_journal)
+	if (sbi->s_journal) {
 		ext4_set_feature_journal_needs_recovery(sb);
+		if (ext4_has_feature_orphan_file(sb))
+			ext4_set_feature_orphan_present(sb);
+	}
 
 	err = ext4_commit_super(sb);
 done:
@@ -3960,6 +3965,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		silent = 1;
 		goto cantfind_ext4;
 	}
+	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
+				ext4_orphan_file_block_trigger);
 
 	/* Load the checksum driver */
 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
@@ -4624,6 +4631,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_root = NULL;
 
 	needs_recovery = (es->s_last_orphan != 0 ||
+			  ext4_has_feature_orphan_present(sb) ||
 			  ext4_has_feature_journal_needs_recovery(sb));
 
 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
@@ -4914,12 +4922,15 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	if (err)
 		goto failed_mount7;
 
+	err = ext4_init_orphan_info(sb);
+	if (err)
+		goto failed_mount8;
 #ifdef CONFIG_QUOTA
 	/* Enable quota usage during mount. */
 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
 		err = ext4_enable_quotas(sb);
 		if (err)
-			goto failed_mount8;
+			goto failed_mount9;
 	}
 #endif  /* CONFIG_QUOTA */
 
@@ -4938,7 +4949,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		ext4_msg(sb, KERN_INFO, "recovery complete");
 		err = ext4_mark_recovery_complete(sb, es);
 		if (err)
-			goto failed_mount8;
+			goto failed_mount9;
 	}
 	if (EXT4_SB(sb)->s_journal) {
 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
@@ -4984,6 +4995,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
 	goto failed_mount;
 
+failed_mount9:
+	ext4_release_orphan_info(sb);
 failed_mount8:
 	ext4_unregister_sysfs(sb);
 	kobject_put(&sbi->s_kobj);
@@ -5494,8 +5507,15 @@ static int ext4_mark_recovery_complete(struct super_block *sb,
 	if (err < 0)
 		goto out;
 
-	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
+	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
+	    ext4_has_feature_orphan_present(sb))) {
+		if (!ext4_orphan_file_empty(sb)) {
+			ext4_error(sb, "Orphan file not empty on read-only fs.");
+			err = -EFSCORRUPTED;
+			goto out;
+		}
 		ext4_clear_feature_journal_needs_recovery(sb);
+		ext4_clear_feature_orphan_present(sb);
 		ext4_commit_super(sb);
 	}
 out:
@@ -5638,6 +5658,8 @@ static int ext4_freeze(struct super_block *sb)
 
 		/* Journal blocked and flushed, clear needs_recovery flag. */
 		ext4_clear_feature_journal_needs_recovery(sb);
+		if (ext4_orphan_file_empty(sb))
+			ext4_clear_feature_orphan_present(sb);
 	}
 
 	error = ext4_commit_super(sb);
@@ -5660,6 +5682,8 @@ static int ext4_unfreeze(struct super_block *sb)
 	if (EXT4_SB(sb)->s_journal) {
 		/* Reset the needs_recovery flag before the fs is unlocked. */
 		ext4_set_feature_journal_needs_recovery(sb);
+		if (ext4_has_feature_orphan_file(sb))
+			ext4_set_feature_orphan_present(sb);
 	}
 
 	ext4_commit_super(sb);
@@ -5863,7 +5887,7 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 			 * around from a previously readonly bdev mount,
 			 * require a full umount/remount for now.
 			 */
-			if (es->s_last_orphan) {
+			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
 				ext4_msg(sb, KERN_WARNING, "Couldn't "
 				       "remount RDWR because of unprocessed "
 				       "orphan inode list.  Please "
-- 
2.26.2

[PATCH 0/5 v4] ext4: Speedup orphan file handling

[Jan Kara]

  Hello,

Here is a fourth version of my series to speed up orphan inode handling in
ext4.

Orphan inode handling in ext4 is a bottleneck for workloads which heavily
excercise truncate / unlink of small files as they contend on global
s_orphan_mutex (when you have fast enough storage). This patch set implements
new way of handling orphan inodes - instead of using a linked list, we store
inode numbers of orphaned inodes in a file which is possible to implement in a
more scalable manner than linked list manipulations. See description of patch
3/5 for more details.

The patch set achieves significant gains both for a micro benchmark stressing
orphan inode handling (truncating file byte-by-byte, several threads in
parallel) and for reaim creat_clo workload. I'm happy for any review, thoughts,
ideas about the patches. I have also implemented full support in e2fsprogs
which I'll send separately.

								Honza

[1] https://lore.kernel.org/lkml/20210227120804.GB22871@xsang-OptiPlex-9020/

Changes since v3:
* Added documentation about on-disk format changes
* Add physical block number into orphan block checksum
* Improve some sanity checks, handling of corrupted orphan file
* Improved some changelogs

Changes since v2:
* Updated some comments
* Rebased onto 5.13-rc5
* Change orphan file inode from a fixed inode number to inode number stored
  in the superblock

Changes since v1:
* orphan blocks have now magic numbers
* split out orphan handling to a separate source file
* some smaller updates according to review

[PATCH 3/5] ext4: Speedup ext4 orphan inode handling

[Jan Kara]

Ext4 orphan inode handling is a bottleneck for workloads which heavily
truncate / unlink small files since it contends on the global
s_orphan_mutex lock (and generally it's difficult to improve scalability
of the ondisk linked list of orphaned inodes).

This patch implements new way of handling orphan inodes. Instead of
linking orphaned inode into a linked list, we store it's inode number in
a new special file which we call "orphan file". Only if there's no more
space in the orphan file (too many inodes are currently orphaned) we
fall back to using old style linked list. Currently we protect
operations in the orphan file with a spinlock for simplicity but even in
this setting we can substantially reduce the length of the critical
section and thus speedup some workloads. In the next patch we improve
this by making orphan handling lockless.

Note that the change is backwards compatible when the filesystem is
clean - the existence of the orphan file is a compat feature, we set
another ro-compat feature indicating orphan file needs scanning for
orphaned inodes when mounting filesystem read-write. This ro-compat
feature gets cleared on unmount / remount read-only.

Some performance data from 80 CPU Xeon Server with 512 GB of RAM,
filesystem located on SSD, average of 5 runs:

stress-orphan (microbenchmark truncating files byte-by-byte from N
processes in parallel)

Threads Time            Time
        Vanilla         Patched
  1       1.057200        0.945600
  2       1.680400        1.331800
  4       2.547000        1.995000
  8       7.049400        6.424200
 16      14.827800       14.937600
 32      40.948200       33.038200
 64      87.787400       60.823600
128     206.504000      122.941400

So we can see significant wins all over the board.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/ext4/ext4.h   |  70 +++++++++-
 fs/ext4/orphan.c | 326 ++++++++++++++++++++++++++++++++++++++++++-----
 fs/ext4/super.c  |  34 ++++-
 3 files changed, 386 insertions(+), 44 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 33508487516f..83298c0b6dae 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1025,7 +1025,14 @@ struct ext4_inode_info {
 	 */
 	struct rw_semaphore xattr_sem;
 
-	struct list_head i_orphan;	/* unlinked but open inodes */
+	/*
+	 * Inodes with EXT4_STATE_ORPHAN_FILE use i_orphan_idx. Otherwise
+	 * i_orphan is used.
+	 */
+	union {
+		struct list_head i_orphan;	/* unlinked but open inodes */
+		unsigned int i_orphan_idx;	/* Index in orphan file */
+	};
 
 	/* Fast commit related info */
 
@@ -1419,7 +1426,8 @@ struct ext4_super_block {
 	__u8    s_last_error_errcode;
 	__le16  s_encoding;		/* Filename charset encoding */
 	__le16  s_encoding_flags;	/* Filename charset encoding flags */
-	__le32	s_reserved[95];		/* Padding to the end of the block */
+	__le32  s_orphan_file_inum;	/* Inode for tracking orphan inodes */
+	__le32	s_reserved[94];		/* Padding to the end of the block */
 	__le32	s_checksum;		/* crc32c(superblock) */
 };
 
@@ -1440,6 +1448,7 @@ struct ext4_super_block {
 
 /* Types of ext4 journal triggers */
 enum ext4_journal_trigger_type {
+	EXT4_JTR_ORPHAN_FILE,
 	EXT4_JTR_NONE	/* This must be the last entry for indexing to work! */
 };
 
@@ -1456,6 +1465,36 @@ static inline struct ext4_journal_trigger *EXT4_TRIGGER(
 	return container_of(trigger, struct ext4_journal_trigger, tr_triggers);
 }
 
+#define EXT4_ORPHAN_BLOCK_MAGIC 0x0b10ca04
+
+/* Structure at the tail of orphan block */
+struct ext4_orphan_block_tail {
+	__le32 ob_magic;
+	__le32 ob_checksum;
+};
+
+static inline int ext4_inodes_per_orphan_block(struct super_block *sb)
+{
+	return (sb->s_blocksize - sizeof(struct ext4_orphan_block_tail)) /
+			sizeof(u32);
+}
+
+struct ext4_orphan_block {
+	int ob_free_entries;	/* Number of free orphan entries in block */
+	struct buffer_head *ob_bh;	/* Buffer for orphan block */
+};
+
+/*
+ * Info about orphan file.
+ */
+struct ext4_orphan_info {
+	spinlock_t of_lock;
+	int of_blocks;			/* Number of orphan blocks in a file */
+	__u32 of_csum_seed;		/* Checksum seed for orphan file */
+	struct ext4_orphan_block *of_binfo;	/* Array with info about orphan
+						 * file blocks */
+};
+
 /*
  * fourth extended-fs super-block data in memory
  */
@@ -1509,9 +1548,11 @@ struct ext4_sb_info {
 
 	/* Journaling */
 	struct journal_s *s_journal;
-	struct list_head s_orphan;
-	struct mutex s_orphan_lock;
 	unsigned long s_ext4_flags;		/* Ext4 superblock flags */
+	struct mutex s_orphan_lock;	/* Protects on disk list changes */
+	struct list_head s_orphan;	/* List of orphaned inodes in on disk
+					   list */
+	struct ext4_orphan_info s_orphan_info;
 	unsigned long s_commit_interval;
 	u32 s_max_batch_time;
 	u32 s_min_batch_time;
@@ -1846,6 +1887,7 @@ enum {
 	EXT4_STATE_LUSTRE_EA_INODE,	/* Lustre-style ea_inode */
 	EXT4_STATE_VERITY_IN_PROGRESS,	/* building fs-verity Merkle tree */
 	EXT4_STATE_FC_COMMITTING,	/* Fast commit ongoing */
+	EXT4_STATE_ORPHAN_FILE,		/* Inode orphaned in orphan file */
 };
 
 #define EXT4_INODE_BIT_FNS(name, field, offset)				\
@@ -1947,6 +1989,7 @@ static inline bool ext4_verity_in_progress(struct inode *inode)
  */
 #define EXT4_FEATURE_COMPAT_FAST_COMMIT		0x0400
 #define EXT4_FEATURE_COMPAT_STABLE_INODES	0x0800
+#define EXT4_FEATURE_COMPAT_ORPHAN_FILE		0x1000	/* Orphan file exists */
 
 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
@@ -1955,6 +1998,8 @@ static inline bool ext4_verity_in_progress(struct inode *inode)
 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK	0x0020
 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE	0x0040
+#define EXT4_FEATURE_RO_COMPAT_ORPHAN_PRESENT	0x0080 /* Orphan file may be
+							  non-empty */
 #define EXT4_FEATURE_RO_COMPAT_QUOTA		0x0100
 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC		0x0200
 /*
@@ -1964,6 +2009,7 @@ static inline bool ext4_verity_in_progress(struct inode *inode)
  * GDT_CSUM bits are mutually exclusive.
  */
 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM	0x0400
+/* 0x0800 Reserved for EXT4_FEATURE_RO_COMPAT_REPLICA */
 #define EXT4_FEATURE_RO_COMPAT_READONLY		0x1000
 #define EXT4_FEATURE_RO_COMPAT_PROJECT		0x2000
 #define EXT4_FEATURE_RO_COMPAT_VERITY		0x8000
@@ -2050,6 +2096,7 @@ EXT4_FEATURE_COMPAT_FUNCS(dir_index,		DIR_INDEX)
 EXT4_FEATURE_COMPAT_FUNCS(sparse_super2,	SPARSE_SUPER2)
 EXT4_FEATURE_COMPAT_FUNCS(fast_commit,		FAST_COMMIT)
 EXT4_FEATURE_COMPAT_FUNCS(stable_inodes,	STABLE_INODES)
+EXT4_FEATURE_COMPAT_FUNCS(orphan_file,		ORPHAN_FILE)
 
 EXT4_FEATURE_RO_COMPAT_FUNCS(sparse_super,	SPARSE_SUPER)
 EXT4_FEATURE_RO_COMPAT_FUNCS(large_file,	LARGE_FILE)
@@ -2064,6 +2111,7 @@ EXT4_FEATURE_RO_COMPAT_FUNCS(metadata_csum,	METADATA_CSUM)
 EXT4_FEATURE_RO_COMPAT_FUNCS(readonly,		READONLY)
 EXT4_FEATURE_RO_COMPAT_FUNCS(project,		PROJECT)
 EXT4_FEATURE_RO_COMPAT_FUNCS(verity,		VERITY)
+EXT4_FEATURE_RO_COMPAT_FUNCS(orphan_present,	ORPHAN_PRESENT)
 
 EXT4_FEATURE_INCOMPAT_FUNCS(compression,	COMPRESSION)
 EXT4_FEATURE_INCOMPAT_FUNCS(filetype,		FILETYPE)
@@ -2097,7 +2145,8 @@ EXT4_FEATURE_INCOMPAT_FUNCS(casefold,		CASEFOLD)
 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
 					 EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
 
-#define EXT4_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
+#define EXT4_FEATURE_COMPAT_SUPP	(EXT4_FEATURE_COMPAT_EXT_ATTR| \
+					 EXT4_FEATURE_COMPAT_ORPHAN_FILE)
 #define EXT4_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
 					 EXT4_FEATURE_INCOMPAT_RECOVER| \
 					 EXT4_FEATURE_INCOMPAT_META_BG| \
@@ -2122,7 +2171,8 @@ EXT4_FEATURE_INCOMPAT_FUNCS(casefold,		CASEFOLD)
 					 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
 					 EXT4_FEATURE_RO_COMPAT_QUOTA |\
 					 EXT4_FEATURE_RO_COMPAT_PROJECT |\
-					 EXT4_FEATURE_RO_COMPAT_VERITY)
+					 EXT4_FEATURE_RO_COMPAT_VERITY |\
+					 EXT4_FEATURE_RO_COMPAT_ORPHAN_PRESENT)
 
 #define EXTN_FEATURE_FUNCS(ver) \
 static inline bool ext4_has_unknown_ext##ver##_compat_features(struct super_block *sb) \
@@ -2172,7 +2222,6 @@ static inline int ext4_forced_shutdown(struct ext4_sb_info *sbi)
 	return test_bit(EXT4_FLAGS_SHUTDOWN, &sbi->s_ext4_flags);
 }
 
-
 /*
  * Default values for user and/or group using reserved blocks
  */
@@ -3751,6 +3800,13 @@ extern int ext4_orphan_add(handle_t *, struct inode *);
 extern int ext4_orphan_del(handle_t *, struct inode *);
 extern void ext4_orphan_cleanup(struct super_block *sb,
 				struct ext4_super_block *es);
+extern void ext4_release_orphan_info(struct super_block *sb);
+extern int ext4_init_orphan_info(struct super_block *sb);
+extern int ext4_orphan_file_empty(struct super_block *sb);
+extern void ext4_orphan_file_block_trigger(
+				struct jbd2_buffer_trigger_type *triggers,
+				struct buffer_head *bh,
+				void *data, size_t size);
 
 /*
  * Add new method to test whether block and inode bitmaps are properly
diff --git a/fs/ext4/orphan.c b/fs/ext4/orphan.c
index edfae0b1dfc9..95c2fa0e4e3e 100644
--- a/fs/ext4/orphan.c
+++ b/fs/ext4/orphan.c
@@ -8,6 +8,52 @@
 #include "ext4.h"
 #include "ext4_jbd2.h"
 
+static int ext4_orphan_file_add(handle_t *handle, struct inode *inode)
+{
+	int i, j;
+	struct ext4_orphan_info *oi = &EXT4_SB(inode->i_sb)->s_orphan_info;
+	int ret = 0;
+	__le32 *bdata;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(inode->i_sb);
+
+	spin_lock(&oi->of_lock);
+	for (i = 0; i < oi->of_blocks && !oi->of_binfo[i].ob_free_entries; i++);
+	if (i == oi->of_blocks) {
+		spin_unlock(&oi->of_lock);
+		/*
+		 * For now we don't grow or shrink orphan file. We just use
+		 * whatever was allocated at mke2fs time. The additional
+		 * credits we would have to reserve for each orphan inode
+		 * operation just don't seem worth it.
+		 */
+		return -ENOSPC;
+	}
+	oi->of_binfo[i].ob_free_entries--;
+	spin_unlock(&oi->of_lock);
+
+	/*
+	 * Get access to orphan block. We have dropped of_lock but since we
+	 * have decremented number of free entries we are guaranteed free entry
+	 * in our block.
+	 */
+	ret = ext4_journal_get_write_access(handle, inode->i_sb,
+				oi->of_binfo[i].ob_bh, EXT4_JTR_ORPHAN_FILE);
+	if (ret)
+		return ret;
+
+	bdata = (__le32 *)(oi->of_binfo[i].ob_bh->b_data);
+	spin_lock(&oi->of_lock);
+	/* Find empty slot in a block */
+	for (j = 0; j < inodes_per_ob && bdata[j]; j++);
+	BUG_ON(j == inodes_per_ob);
+	bdata[j] = cpu_to_le32(inode->i_ino);
+	EXT4_I(inode)->i_orphan_idx = i * inodes_per_ob + j;
+	ext4_set_inode_state(inode, EXT4_STATE_ORPHAN_FILE);
+	spin_unlock(&oi->of_lock);
+
+	return ext4_handle_dirty_metadata(handle, NULL, oi->of_binfo[i].ob_bh);
+}
+
 /*
  * ext4_orphan_add() links an unlinked or truncated inode into a list of
  * such inodes, starting at the superblock, in case we crash before the
@@ -34,10 +80,10 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode)
 	WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
 		     !inode_is_locked(inode));
 	/*
-	 * Exit early if inode already is on orphan list. This is a big speedup
-	 * since we don't have to contend on the global s_orphan_lock.
+	 * Inode orphaned in orphan file or in orphan list?
 	 */
-	if (!list_empty(&EXT4_I(inode)->i_orphan))
+	if (ext4_test_inode_state(inode, EXT4_STATE_ORPHAN_FILE) ||
+	    !list_empty(&EXT4_I(inode)->i_orphan))
 		return 0;
 
 	/*
@@ -49,6 +95,16 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode)
 	ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 		  S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
 
+	if (sbi->s_orphan_info.of_blocks) {
+		err = ext4_orphan_file_add(handle, inode);
+		/*
+		 * Fallback to normal orphan list of orphan file is
+		 * out of space
+		 */
+		if (err != -ENOSPC)
+			return err;
+	}
+
 	BUFFER_TRACE(sbi->s_sbh, "get_write_access");
 	err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,
 					    EXT4_JTR_NONE);
@@ -103,6 +159,39 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode)
 	return err;
 }
 
+static int ext4_orphan_file_del(handle_t *handle, struct inode *inode)
+{
+	struct ext4_orphan_info *oi = &EXT4_SB(inode->i_sb)->s_orphan_info;
+	__le32 *bdata;
+	int blk, off;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(inode->i_sb);
+	int ret = 0;
+
+	if (!handle)
+		goto out;
+	blk = EXT4_I(inode)->i_orphan_idx / inodes_per_ob;
+	off = EXT4_I(inode)->i_orphan_idx % inodes_per_ob;
+	if (WARN_ON_ONCE(blk >= oi->of_blocks))
+		goto out;
+
+	ret = ext4_journal_get_write_access(handle, inode->i_sb,
+				oi->of_binfo[blk].ob_bh, EXT4_JTR_ORPHAN_FILE);
+	if (ret)
+		goto out;
+
+	bdata = (__le32 *)(oi->of_binfo[blk].ob_bh->b_data);
+	spin_lock(&oi->of_lock);
+	bdata[off] = 0;
+	oi->of_binfo[blk].ob_free_entries++;
+	spin_unlock(&oi->of_lock);
+	ret = ext4_handle_dirty_metadata(handle, NULL, oi->of_binfo[blk].ob_bh);
+out:
+	ext4_clear_inode_state(inode, EXT4_STATE_ORPHAN_FILE);
+	INIT_LIST_HEAD(&EXT4_I(inode)->i_orphan);
+
+	return ret;
+}
+
 /*
  * ext4_orphan_del() removes an unlinked or truncated inode from the list
  * of such inodes stored on disk, because it is finally being cleaned up.
@@ -121,6 +210,9 @@ int ext4_orphan_del(handle_t *handle, struct inode *inode)
 
 	WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
 		     !inode_is_locked(inode));
+	if (ext4_test_inode_state(inode, EXT4_STATE_ORPHAN_FILE))
+		return ext4_orphan_file_del(handle, inode);
+
 	/* Do this quick check before taking global s_orphan_lock. */
 	if (list_empty(&ei->i_orphan))
 		return 0;
@@ -200,6 +292,39 @@ static int ext4_quota_on_mount(struct super_block *sb, int type)
 }
 #endif
 
+static void ext4_process_orphan(struct inode *inode,
+				int *nr_truncates, int *nr_orphans)
+{
+	struct super_block *sb = inode->i_sb;
+	int ret;
+
+	dquot_initialize(inode);
+	if (inode->i_nlink) {
+		if (test_opt(sb, DEBUG))
+			ext4_msg(sb, KERN_DEBUG,
+				"%s: truncating inode %lu to %lld bytes",
+				__func__, inode->i_ino, inode->i_size);
+		jbd_debug(2, "truncating inode %lu to %lld bytes\n",
+			  inode->i_ino, inode->i_size);
+		inode_lock(inode);
+		truncate_inode_pages(inode->i_mapping, inode->i_size);
+		ret = ext4_truncate(inode);
+		if (ret)
+			ext4_std_error(inode->i_sb, ret);
+		inode_unlock(inode);
+		(*nr_truncates)++;
+	} else {
+		if (test_opt(sb, DEBUG))
+			ext4_msg(sb, KERN_DEBUG,
+				"%s: deleting unreferenced inode %lu",
+				__func__, inode->i_ino);
+		jbd_debug(2, "deleting unreferenced inode %lu\n",
+			  inode->i_ino);
+		(*nr_orphans)++;
+	}
+	iput(inode);  /* The delete magic happens here! */
+}
+
 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
  * the superblock) which were deleted from all directories, but held open by
  * a process at the time of a crash.  We walk the list and try to delete these
@@ -220,12 +345,17 @@ static int ext4_quota_on_mount(struct super_block *sb, int type)
 void ext4_orphan_cleanup(struct super_block *sb, struct ext4_super_block *es)
 {
 	unsigned int s_flags = sb->s_flags;
-	int ret, nr_orphans = 0, nr_truncates = 0;
+	int nr_orphans = 0, nr_truncates = 0;
+	struct inode *inode;
+	int i, j;
 #ifdef CONFIG_QUOTA
 	int quota_update = 0;
-	int i;
 #endif
-	if (!es->s_last_orphan) {
+	__le32 *bdata;
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
+
+	if (!es->s_last_orphan && !oi->of_blocks) {
 		jbd_debug(4, "no orphan inodes to clean up\n");
 		return;
 	}
@@ -289,8 +419,6 @@ void ext4_orphan_cleanup(struct super_block *sb, struct ext4_super_block *es)
 #endif
 
 	while (es->s_last_orphan) {
-		struct inode *inode;
-
 		/*
 		 * We may have encountered an error during cleanup; if
 		 * so, skip the rest.
@@ -308,31 +436,21 @@ void ext4_orphan_cleanup(struct super_block *sb, struct ext4_super_block *es)
 		}
 
 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
-		dquot_initialize(inode);
-		if (inode->i_nlink) {
-			if (test_opt(sb, DEBUG))
-				ext4_msg(sb, KERN_DEBUG,
-					"%s: truncating inode %lu to %lld bytes",
-					__func__, inode->i_ino, inode->i_size);
-			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
-				  inode->i_ino, inode->i_size);
-			inode_lock(inode);
-			truncate_inode_pages(inode->i_mapping, inode->i_size);
-			ret = ext4_truncate(inode);
-			if (ret)
-				ext4_std_error(inode->i_sb, ret);
-			inode_unlock(inode);
-			nr_truncates++;
-		} else {
-			if (test_opt(sb, DEBUG))
-				ext4_msg(sb, KERN_DEBUG,
-					"%s: deleting unreferenced inode %lu",
-					__func__, inode->i_ino);
-			jbd_debug(2, "deleting unreferenced inode %lu\n",
-				  inode->i_ino);
-			nr_orphans++;
+		ext4_process_orphan(inode, &nr_truncates, &nr_orphans);
+	}
+
+	for (i = 0; i < oi->of_blocks; i++) {
+		bdata = (__le32 *)(oi->of_binfo[i].ob_bh->b_data);
+		for (j = 0; j < inodes_per_ob; j++) {
+			if (!bdata[j])
+				continue;
+			inode = ext4_orphan_get(sb, le32_to_cpu(bdata[j]));
+			if (IS_ERR(inode))
+				continue;
+			ext4_set_inode_state(inode, EXT4_STATE_ORPHAN_FILE);
+			EXT4_I(inode)->i_orphan_idx = i * inodes_per_ob + j;
+			ext4_process_orphan(inode, &nr_truncates, &nr_orphans);
 		}
-		iput(inode);  /* The delete magic happens here! */
 	}
 
 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
@@ -354,3 +472,147 @@ void ext4_orphan_cleanup(struct super_block *sb, struct ext4_super_block *es)
 #endif
 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
 }
+
+void ext4_release_orphan_info(struct super_block *sb)
+{
+	int i;
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+
+	if (!oi->of_blocks)
+		return;
+	for (i = 0; i < oi->of_blocks; i++)
+		brelse(oi->of_binfo[i].ob_bh);
+	kfree(oi->of_binfo);
+}
+
+static struct ext4_orphan_block_tail *ext4_orphan_block_tail(
+						struct super_block *sb,
+						struct buffer_head *bh)
+{
+	return (struct ext4_orphan_block_tail *)(bh->b_data + sb->s_blocksize -
+				sizeof(struct ext4_orphan_block_tail));
+}
+
+static int ext4_orphan_file_block_csum_verify(struct super_block *sb,
+					      struct buffer_head *bh)
+{
+	__u32 calculated;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+	struct ext4_orphan_block_tail *ot;
+	__le64 dsk_block_nr = cpu_to_le64(bh->b_blocknr);
+
+	if (!ext4_has_metadata_csum(sb))
+		return 1;
+
+	ot = ext4_orphan_block_tail(sb, bh);
+	calculated = ext4_chksum(EXT4_SB(sb), oi->of_csum_seed,
+				 (__u8 *)&dsk_block_nr, sizeof(dsk_block_nr));
+	calculated = ext4_chksum(EXT4_SB(sb), calculated, (__u8 *)bh->b_data,
+				 inodes_per_ob * sizeof(__u32));
+	return le32_to_cpu(ot->ob_checksum) == calculated;
+}
+
+/* This gets called only when checksumming is enabled */
+void ext4_orphan_file_block_trigger(struct jbd2_buffer_trigger_type *triggers,
+				    struct buffer_head *bh,
+				    void *data, size_t size)
+{
+	struct super_block *sb = EXT4_TRIGGER(triggers)->sb;
+	__u32 csum;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+	struct ext4_orphan_block_tail *ot;
+	__le64 dsk_block_nr = cpu_to_le64(bh->b_blocknr);
+
+	csum = ext4_chksum(EXT4_SB(sb), oi->of_csum_seed,
+			   (__u8 *)&dsk_block_nr, sizeof(dsk_block_nr));
+	csum = ext4_chksum(EXT4_SB(sb), csum, (__u8 *)data,
+			   inodes_per_ob * sizeof(__u32));
+	ot = ext4_orphan_block_tail(sb, bh);
+	ot->ob_checksum = cpu_to_le32(csum);
+}
+
+int ext4_init_orphan_info(struct super_block *sb)
+{
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+	struct inode *inode;
+	int i, j;
+	int ret;
+	int free;
+	__le32 *bdata;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
+	struct ext4_orphan_block_tail *ot;
+	ino_t orphan_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_orphan_file_inum);
+
+	spin_lock_init(&oi->of_lock);
+
+	if (!ext4_has_feature_orphan_file(sb))
+		return 0;
+
+	inode = ext4_iget(sb, orphan_ino, EXT4_IGET_NORMAL);
+	if (IS_ERR(inode)) {
+		ext4_msg(sb, KERN_ERR, "get orphan inode failed");
+		return PTR_ERR(inode);
+	}
+	oi->of_blocks = inode->i_size >> sb->s_blocksize_bits;
+	oi->of_csum_seed = EXT4_I(inode)->i_csum_seed;
+	oi->of_binfo = kmalloc(oi->of_blocks*sizeof(struct ext4_orphan_block),
+			       GFP_KERNEL);
+	if (!oi->of_binfo) {
+		ret = -ENOMEM;
+		goto out_put;
+	}
+	for (i = 0; i < oi->of_blocks; i++) {
+		oi->of_binfo[i].ob_bh = ext4_bread(NULL, inode, i, 0);
+		if (IS_ERR(oi->of_binfo[i].ob_bh)) {
+			ret = PTR_ERR(oi->of_binfo[i].ob_bh);
+			goto out_free;
+		}
+		if (!oi->of_binfo[i].ob_bh) {
+			ret = -EIO;
+			goto out_free;
+		}
+		ot = ext4_orphan_block_tail(sb, oi->of_binfo[i].ob_bh);
+		if (le32_to_cpu(ot->ob_magic) != EXT4_ORPHAN_BLOCK_MAGIC) {
+			ext4_error(sb, "orphan file block %d: bad magic", i);
+			ret = -EIO;
+			goto out_free;
+		}
+		if (!ext4_orphan_file_block_csum_verify(sb,
+						oi->of_binfo[i].ob_bh)) {
+			ext4_error(sb, "orphan file block %d: bad checksum", i);
+			ret = -EIO;
+			goto out_free;
+		}
+		bdata = (__le32 *)(oi->of_binfo[i].ob_bh->b_data);
+		free = 0;
+		for (j = 0; j < inodes_per_ob; j++)
+			if (bdata[j] == 0)
+				free++;
+		oi->of_binfo[i].ob_free_entries = free;
+	}
+	iput(inode);
+	return 0;
+out_free:
+	for (i--; i >= 0; i--)
+		brelse(oi->of_binfo[i].ob_bh);
+	kfree(oi->of_binfo);
+out_put:
+	iput(inode);
+	return ret;
+}
+
+int ext4_orphan_file_empty(struct super_block *sb)
+{
+	struct ext4_orphan_info *oi = &EXT4_SB(sb)->s_orphan_info;
+	int i;
+	int inodes_per_ob = ext4_inodes_per_orphan_block(sb);
+
+	if (!ext4_has_feature_orphan_file(sb))
+		return 1;
+	for (i = 0; i < oi->of_blocks; i++)
+		if (oi->of_binfo[i].ob_free_entries != inodes_per_ob)
+			return 0;
+	return 1;
+}
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 6e43c8546dc5..06f63b0cd988 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1164,6 +1164,7 @@ static void ext4_put_super(struct super_block *sb)
 
 	flush_work(&sbi->s_error_work);
 	destroy_workqueue(sbi->rsv_conversion_wq);
+	ext4_release_orphan_info(sb);
 
 	/*
 	 * Unregister sysfs before destroying jbd2 journal.
@@ -1189,6 +1190,7 @@ static void ext4_put_super(struct super_block *sb)
 
 	if (!sb_rdonly(sb) && !aborted) {
 		ext4_clear_feature_journal_needs_recovery(sb);
+		ext4_clear_feature_orphan_present(sb);
 		es->s_state = cpu_to_le16(sbi->s_mount_state);
 	}
 	if (!sb_rdonly(sb))
@@ -2695,8 +2697,11 @@ static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
 	le16_add_cpu(&es->s_mnt_count, 1);
 	ext4_update_tstamp(es, s_mtime);
-	if (sbi->s_journal)
+	if (sbi->s_journal) {
 		ext4_set_feature_journal_needs_recovery(sb);
+		if (ext4_has_feature_orphan_file(sb))
+			ext4_set_feature_orphan_present(sb);
+	}
 
 	err = ext4_commit_super(sb);
 done:
@@ -3971,6 +3976,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		silent = 1;
 		goto cantfind_ext4;
 	}
+	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
+				ext4_orphan_file_block_trigger);
 
 	/* Load the checksum driver */
 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
@@ -4635,6 +4642,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_root = NULL;
 
 	needs_recovery = (es->s_last_orphan != 0 ||
+			  ext4_has_feature_orphan_present(sb) ||
 			  ext4_has_feature_journal_needs_recovery(sb));
 
 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
@@ -4924,12 +4932,15 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	if (err)
 		goto failed_mount7;
 
+	err = ext4_init_orphan_info(sb);
+	if (err)
+		goto failed_mount8;
 #ifdef CONFIG_QUOTA
 	/* Enable quota usage during mount. */
 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
 		err = ext4_enable_quotas(sb);
 		if (err)
-			goto failed_mount8;
+			goto failed_mount9;
 	}
 #endif  /* CONFIG_QUOTA */
 
@@ -4948,7 +4959,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		ext4_msg(sb, KERN_INFO, "recovery complete");
 		err = ext4_mark_recovery_complete(sb, es);
 		if (err)
-			goto failed_mount8;
+			goto failed_mount9;
 	}
 	if (EXT4_SB(sb)->s_journal) {
 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
@@ -4994,6 +5005,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
 	goto failed_mount;
 
+failed_mount9:
+	ext4_release_orphan_info(sb);
 failed_mount8:
 	ext4_unregister_sysfs(sb);
 	kobject_put(&sbi->s_kobj);
@@ -5505,8 +5518,15 @@ static int ext4_mark_recovery_complete(struct super_block *sb,
 	if (err < 0)
 		goto out;
 
-	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
+	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
+	    ext4_has_feature_orphan_present(sb))) {
+		if (!ext4_orphan_file_empty(sb)) {
+			ext4_error(sb, "Orphan file not empty on read-only fs.");
+			err = -EFSCORRUPTED;
+			goto out;
+		}
 		ext4_clear_feature_journal_needs_recovery(sb);
+		ext4_clear_feature_orphan_present(sb);
 		ext4_commit_super(sb);
 	}
 out:
@@ -5649,6 +5669,8 @@ static int ext4_freeze(struct super_block *sb)
 
 		/* Journal blocked and flushed, clear needs_recovery flag. */
 		ext4_clear_feature_journal_needs_recovery(sb);
+		if (ext4_orphan_file_empty(sb))
+			ext4_clear_feature_orphan_present(sb);
 	}
 
 	error = ext4_commit_super(sb);
@@ -5671,6 +5693,8 @@ static int ext4_unfreeze(struct super_block *sb)
 	if (EXT4_SB(sb)->s_journal) {
 		/* Reset the needs_recovery flag before the fs is unlocked. */
 		ext4_set_feature_journal_needs_recovery(sb);
+		if (ext4_has_feature_orphan_file(sb))
+			ext4_set_feature_orphan_present(sb);
 	}
 
 	ext4_commit_super(sb);
@@ -5876,7 +5900,7 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 			 * around from a previously readonly bdev mount,
 			 * require a full umount/remount for now.
 			 */
-			if (es->s_last_orphan) {
+			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
 				ext4_msg(sb, KERN_WARNING, "Couldn't "
 				       "remount RDWR because of unprocessed "
 				       "orphan inode list.  Please "
-- 
2.26.2