Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:
"Only miscellaneous cleanups and bug fixes for ext4 this cycle"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: create ext4_kset dynamically
ext4: create ext4_feat kobject dynamically
ext4: release kobject/kset even when init/register fail
ext4: fix incorrect indentation of if statement
ext4: correct documentation for grpid mount option
ext4: use 'sbi' instead of 'EXT4_SB(sb)'
ext4: save error to disk in __ext4_grp_locked_error()
jbd2: fix sphinx kernel-doc build warnings
ext4: fix a race in the ext4 shutdown path
mbcache: make sure c_entry_count is not decremented past zero
ext4: no need flush workqueue before destroying it
ext4: fixed alignment and minor code cleanup in ext4.h
ext4: fix ENOSPC handling in DAX page fault handler
dax: pass detailed error code from dax_iomap_fault()
mbcache: revert "fs/mbcache.c: make count_objects() more robust"
mbcache: initialize entry->e_referenced in mb_cache_entry_create()
ext4: fix up remaining files with SPDX cleanups

Documentation/filesystems/ext4.txt

···
 data_err=abort		Abort the journal if an error occurs in a file
 			data buffer in ordered mode.
 
-grpid			Give objects the same group ID as their creator.
+grpid			New objects have the group ID of their parent.
 bsdgroups
 
 nogrpid		(*)	New objects have the group ID of their creator.

fs/dax.c

···
 }
 
 static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
-			       const struct iomap_ops *ops)
+			       int *iomap_errp, const struct iomap_ops *ops)
 {
 	struct vm_area_struct *vma = vmf->vma;
 	struct address_space *mapping = vma->vm_file->f_mapping;
···
 	 * that we never have to deal with more than a single extent here.
 	 */
 	error = ops->iomap_begin(inode, pos, PAGE_SIZE, flags, &iomap);
+	if (iomap_errp)
+		*iomap_errp = error;
 	if (error) {
 		vmf_ret = dax_fault_return(error);
 		goto unlock_entry;
···
  * @vmf: The description of the fault
  * @pe_size: Size of the page to fault in
  * @pfnp: PFN to insert for synchronous faults if fsync is required
+ * @iomap_errp: Storage for detailed error code in case of error
  * @ops: Iomap ops passed from the file system
  *
  * When a page fault occurs, filesystems may call this helper in
···
  * successfully.
  */
 int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
-		    pfn_t *pfnp, const struct iomap_ops *ops)
+		    pfn_t *pfnp, int *iomap_errp, const struct iomap_ops *ops)
 {
 	switch (pe_size) {
 	case PE_SIZE_PTE:
-		return dax_iomap_pte_fault(vmf, pfnp, ops);
+		return dax_iomap_pte_fault(vmf, pfnp, iomap_errp, ops);
 	case PE_SIZE_PMD:
 		return dax_iomap_pmd_fault(vmf, pfnp, ops);
 	default:

fs/ext2/file.c

···
 	}
 	down_read(&ei->dax_sem);
 
-	ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &ext2_iomap_ops);
+	ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, NULL, &ext2_iomap_ops);
 
 	up_read(&ei->dax_sem);
 	if (vmf->flags & FAULT_FLAG_WRITE)

fs/ext4/acl.h

···
-/* SPDX-License-Identifier: GPL-2.0 */
+// SPDX-License-Identifier: GPL-2.0
 /*
   File: fs/ext4/acl.h
 

fs/ext4/balloc.c

···
 	blk = ext4_inode_table(sb, desc);
 	offset = blk - group_first_block;
 	next_zero_bit = ext4_find_next_zero_bit(bh->b_data,
-			EXT4_B2C(sbi, offset + EXT4_SB(sb)->s_itb_per_group),
+			EXT4_B2C(sbi, offset + sbi->s_itb_per_group),
 			EXT4_B2C(sbi, offset));
 	if (next_zero_bit <
-	    EXT4_B2C(sbi, offset + EXT4_SB(sb)->s_itb_per_group))
+	    EXT4_B2C(sbi, offset + sbi->s_itb_per_group))
 		/* bad bitmap for inode tables */
 		return blk;
 	return 0;

fs/ext4/block_validity.c

···
 	int ret;
 
 	if (!test_opt(sb, BLOCK_VALIDITY)) {
-		if (EXT4_SB(sb)->system_blks.rb_node)
+		if (sbi->system_blks.rb_node)
 			ext4_release_system_zone(sb);
 		return 0;
 	}
-	if (EXT4_SB(sb)->system_blks.rb_node)
+	if (sbi->system_blks.rb_node)
 		return 0;
 
 	for (i=0; i < ngroups; i++) {
···
 	}
 
 	if (test_opt(sb, DEBUG))
-		debug_print_tree(EXT4_SB(sb));
+		debug_print_tree(sbi);
 	return 0;
 }
 

fs/ext4/ext4.h

···
-/* SPDX-License-Identifier: GPL-2.0 */
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  ext4.h
  *
···
 /*
  * Flags used by ext4_free_blocks
  */
-#define EXT4_FREE_BLOCKS_METADATA	0x0001
-#define EXT4_FREE_BLOCKS_FORGET		0x0002
-#define EXT4_FREE_BLOCKS_VALIDATED	0x0004
-#define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE	0x0008
+#define EXT4_FREE_BLOCKS_METADATA		0x0001
+#define EXT4_FREE_BLOCKS_FORGET			0x0002
+#define EXT4_FREE_BLOCKS_VALIDATED		0x0004
+#define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE		0x0008
 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER	0x0010
 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER	0x0020
 
···
 
 /* Legal values for the dx_root hash_version field: */
 
-#define DX_HASH_LEGACY		0
-#define DX_HASH_HALF_MD4	1
-#define DX_HASH_TEA		2
-#define DX_HASH_LEGACY_UNSIGNED	3
+#define DX_HASH_LEGACY			0
+#define DX_HASH_HALF_MD4		1
+#define DX_HASH_TEA			2
+#define DX_HASH_LEGACY_UNSIGNED		3
 #define DX_HASH_HALF_MD4_UNSIGNED	4
 #define DX_HASH_TEA_UNSIGNED		5
 
···
 		struct shash_desc shash;
 		char ctx[4];
 	} desc;
-	int err;
 
 	BUG_ON(crypto_shash_descsize(sbi->s_chksum_driver)!=sizeof(desc.ctx));
 
···
 	desc.shash.flags = 0;
 	*(u32 *)desc.ctx = crc;
 
-	err = crypto_shash_update(&desc.shash, address, length);
-	BUG_ON(err);
+	BUG_ON(crypto_shash_update(&desc.shash, address, length));
 
 	return *(u32 *)desc.ctx;
 }

fs/ext4/ext4_extents.h

···
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (c) 2003-2006, Cluster File Systems, Inc, [e-mail]
  * Written by Alex Tomas <[e-mail]>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
  */
 
 #ifndef _EXT4_EXTENTS

fs/ext4/ext4_jbd2.h

···
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * ext4_jbd2.h
  *
  * Written by Stephen C. Tweedie <[e-mail]>, 1999
  *
  * Copyright 1998--1999 Red Hat corp --- All Rights Reserved
- *
- * This file is part of the Linux kernel and is made available under
- * the terms of the GNU General Public License, version 2, or at your
- * option, any later version, incorporated herein by reference.
  *
  * Ext4-specific journaling extensions.
  */

fs/ext4/extents.c

···
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (c) 2003-2006, Cluster File Systems, Inc, [e-mail]
  * Written by Alex Tomas <[e-mail]>
···
  * Architecture independence:
  *   Copyright (c) 2005, Bull S.A.
  *   Written by Pierre Peiffer <[e-mail]>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
  */
 
 /*

fs/ext4/extents_status.h

···
-/* SPDX-License-Identifier: GPL-2.0 */
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  fs/ext4/extents_status.h
  *

fs/ext4/file.c

···
 static int ext4_dax_huge_fault(struct vm_fault *vmf,
 		enum page_entry_size pe_size)
 {
-	int result;
+	int result, error = 0;
+	int retries = 0;
 	handle_t *handle = NULL;
 	struct inode *inode = file_inode(vmf->vma->vm_file);
 	struct super_block *sb = inode->i_sb;
···
 		sb_start_pagefault(sb);
 		file_update_time(vmf->vma->vm_file);
 		down_read(&EXT4_I(inode)->i_mmap_sem);
+retry:
 		handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
 					       EXT4_DATA_TRANS_BLOCKS(sb));
 		if (IS_ERR(handle)) {
···
 	} else {
 		down_read(&EXT4_I(inode)->i_mmap_sem);
 	}
-	result = dax_iomap_fault(vmf, pe_size, &pfn, &ext4_iomap_ops);
+	result = dax_iomap_fault(vmf, pe_size, &pfn, &error, &ext4_iomap_ops);
 	if (write) {
 		ext4_journal_stop(handle);
+
+		if ((result & VM_FAULT_ERROR) && error == -ENOSPC &&
+		    ext4_should_retry_alloc(sb, &retries))
+			goto retry;
 		/* Handling synchronous page fault? */
 		if (result & VM_FAULT_NEEDDSYNC)
 			result = dax_finish_sync_fault(vmf, pe_size, pfn);

fs/ext4/fsmap.c

···
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (C) 2017 Oracle.  All Rights Reserved.
  *
  * Author: Darrick J. Wong <[e-mail]>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it would be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write the Free Software Foundation,
- * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
  */
 #include "ext4.h"
 #include <linux/fsmap.h>

fs/ext4/fsmap.h

···
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (C) 2017 Oracle.  All Rights Reserved.
  *
  * Author: Darrick J. Wong <[e-mail]>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it would be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write the Free Software Foundation,
- * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
  */
 #ifndef __EXT4_FSMAP_H__
 #define	__EXT4_FSMAP_H__

fs/ext4/hash.c

···
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  linux/fs/ext4/hash.c
  *
  * Copyright (C) 2002 by Theodore Ts'o
- *
- * This file is released under the GPL v2.
- *
- * This file may be redistributed under the terms of the GNU Public
- * License.
  */
 
 #include <linux/fs.h>

fs/ext4/ialloc.c

···
 	/* Do this BEFORE marking the inode not in use or returning an error */
 	ext4_clear_inode(inode);
 
-	es = EXT4_SB(sb)->s_es;
+	es = sbi->s_es;
 	if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
 		ext4_error(sb, "reserved or nonexistent inode %lu", ino);
 		goto error_return;
···
 	ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
 	ext4_set_inode_state(inode, EXT4_STATE_NEW);
 
-	ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize;
+	ei->i_extra_isize = sbi->s_want_extra_isize;
 	ei->i_inline_off = 0;
 	if (ext4_has_feature_inline_data(sb))
 		ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);

fs/ext4/inline.c

···
+// SPDX-License-Identifier: LGPL-2.1
 /*
  * Copyright (c) 2012 Taobao.
  * Written by Tao Ma <[e-mail]>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of version 2.1 of the GNU Lesser General Public License
- * as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
  */
 
 #include <linux/iomap.h>

fs/ext4/inode.c

···
 		/* Credits for sb + inode write */
 		handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
 		if (IS_ERR(handle)) {
-			/* This is really bad luck. We've written the data
-			 * but cannot extend i_size. Bail out and pretend
-			 * the write failed... */
-			ret = PTR_ERR(handle);
+			/*
+			 * We wrote the data but cannot extend
+			 * i_size. Bail out. In async io case, we do
+			 * not return error here because we have
+			 * already submmitted the corresponding
+			 * bio. Returning error here makes the caller
+			 * think that this IO is done and failed
+			 * resulting in race with bio's completion
+			 * handler.
+			 */
+			if (!ret)
+				ret = PTR_ERR(handle);
 			if (inode->i_nlink)
 				ext4_orphan_del(NULL, inode);
 

fs/ext4/mballoc.c

···
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (c) 2003-2006, Cluster File Systems, Inc, [e-mail]
  * Written by Alex Tomas <[e-mail]>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
  */
 
 
···
 	clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state));
 
 	period = get_cycles() - period;
-	spin_lock(&EXT4_SB(sb)->s_bal_lock);
-	EXT4_SB(sb)->s_mb_buddies_generated++;
-	EXT4_SB(sb)->s_mb_generation_time += period;
-	spin_unlock(&EXT4_SB(sb)->s_bal_lock);
+	spin_lock(&sbi->s_bal_lock);
+	sbi->s_mb_buddies_generated++;
+	sbi->s_mb_generation_time += period;
+	spin_unlock(&sbi->s_bal_lock);
 }
 
 static void mb_regenerate_buddy(struct ext4_buddy *e4b)
···
 		ext4_fsblk_t blocknr;
 
 		blocknr = ext4_group_first_block_no(sb, e4b->bd_group);
-		blocknr += EXT4_C2B(EXT4_SB(sb), block);
+		blocknr += EXT4_C2B(sbi, block);
 		ext4_grp_locked_error(sb, e4b->bd_group,
 				      inode ? inode->i_ino : 0,
 				      blocknr,
···
 	if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
 	    in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
 	    in_range(block, ext4_inode_table(sb, gdp),
-		     EXT4_SB(sb)->s_itb_per_group) ||
+		     sbi->s_itb_per_group) ||
 	    in_range(block + count - 1, ext4_inode_table(sb, gdp),
-		     EXT4_SB(sb)->s_itb_per_group)) {
+		     sbi->s_itb_per_group)) {
 
 		ext4_error(sb, "Freeing blocks in system zone - "
 			   "Block = %llu, count = %lu", block, count);

fs/ext4/mballoc.h

···
-/* SPDX-License-Identifier: GPL-2.0 */
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  fs/ext4/mballoc.h
  *

fs/ext4/migrate.c

···
+// SPDX-License-Identifier: LGPL-2.1
 /*
  * Copyright IBM Corporation, 2007
  * Author Aneesh Kumar K.V <[e-mail]>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of version 2.1 of the GNU Lesser General Public License
- * as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it would be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  *
  */
 

fs/ext4/move_extent.c

···
+// SPDX-License-Identifier: LGPL-2.1
 /*
  * Copyright (c) 2008,2009 NEC Software Tohoku, Ltd.
  * Written by Takashi Sato <[e-mail]>
  *            Akira Fujita <[e-mail]>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of version 2.1 of the GNU Lesser General Public License
- * as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
  */
 
 #include <linux/fs.h>

fs/ext4/namei.c

···
 	if (err)
 		return err;
 
-       if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
-	   (!projid_eq(EXT4_I(dir)->i_projid,
-		       EXT4_I(old_dentry->d_inode)->i_projid)))
+	if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
+	    (!projid_eq(EXT4_I(dir)->i_projid,
+			EXT4_I(old_dentry->d_inode)->i_projid)))
 		return -EXDEV;
 
 	err = dquot_initialize(dir);

fs/ext4/resize.c

···
 		goto exit_journal;
 
 	group = flex_gd->groups[0].group;
-	BUG_ON(group != EXT4_SB(sb)->s_groups_count);
+	BUG_ON(group != sbi->s_groups_count);
 	err = ext4_add_new_descs(handle, sb, group,
 				resize_inode, flex_gd->count);
 	if (err)

fs/ext4/super.c

···
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  linux/fs/ext4/super.c
  *
···
 	}
 
 	ext4_unlock_group(sb, grp);
+	ext4_commit_super(sb, 1);
 	ext4_handle_error(sb);
 	/*
 	 * We only get here in the ERRORS_RO case; relocking the group
···
 	ext4_unregister_li_request(sb);
 	ext4_quota_off_umount(sb);
 
-	flush_workqueue(sbi->rsv_conversion_wq);
 	destroy_workqueue(sbi->rsv_conversion_wq);
 
 	if (sbi->s_journal) {
···
 	 * compensate.
 	 */
 	if (sb->s_blocksize == 1024 && nr == 0 &&
-	    le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
+	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
 		has_super++;
 
 	return (has_super + ext4_group_first_block_no(sb, bg));
···
 {
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	struct ext4_li_request *elr = NULL;
-	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
+	ext4_group_t ngroups = sbi->s_groups_count;
 	int ret = 0;
 
 	mutex_lock(&ext4_li_mtx);
···
 	bool needs_barrier = false;
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 
-	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
+	if (unlikely(ext4_forced_shutdown(sbi)))
 		return 0;
 
 	trace_ext4_sync_fs(sb, wait);

fs/ext4/sysfs.c

···
 #include <linux/time.h>
 #include <linux/fs.h>
 #include <linux/seq_file.h>
+#include <linux/slab.h>
 #include <linux/proc_fs.h>
 
 #include "ext4.h"
···
 	complete(&sbi->s_kobj_unregister);
 }
 
+static void ext4_kset_release(struct kobject *kobj)
+{
+	struct kset *kset = container_of(kobj, struct kset, kobj);
+
+	kfree(kset);
+}
+
 static const struct sysfs_ops ext4_attr_ops = {
 	.show	= ext4_attr_show,
 	.store	= ext4_attr_store,
···
 
 static struct kobj_type ext4_ktype = {
 	.sysfs_ops	= &ext4_attr_ops,
+	.release	= ext4_kset_release,
 };
 
-static struct kset ext4_kset = {
-	.kobj   = {.ktype = &ext4_ktype},
-};
+static struct kset *ext4_kset;
 
 static struct kobj_type ext4_feat_ktype = {
 	.default_attrs	= ext4_feat_attrs,
 	.sysfs_ops	= &ext4_attr_ops,
+	.release	= (void (*)(struct kobject *))kfree,
 };
 
-static struct kobject ext4_feat = {
-	.kset	= &ext4_kset,
-};
+static struct kobject *ext4_feat;
 
 #define PROC_FILE_SHOW_DEFN(name) \
 static int name##_open(struct inode *inode, struct file *file) \
···
 	const struct ext4_proc_files *p;
 	int err;
 
-	sbi->s_kobj.kset = &ext4_kset;
+	sbi->s_kobj.kset = ext4_kset;
 	init_completion(&sbi->s_kobj_unregister);
 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, NULL,
 				   "%s", sb->s_id);
-	if (err)
+	if (err) {
+		kobject_put(&sbi->s_kobj);
+		wait_for_completion(&sbi->s_kobj_unregister);
 		return err;
+	}
 
 	if (ext4_proc_root)
 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
···
 {
 	int ret;
 
-	kobject_set_name(&ext4_kset.kobj, "ext4");
-	ext4_kset.kobj.parent = fs_kobj;
-	ret = kset_register(&ext4_kset);
-	if (ret)
-		return ret;
+	ext4_kset = kzalloc(sizeof(*ext4_kset), GFP_KERNEL);
+	if (!ext4_kset)
+		return -ENOMEM;
 
-	ret = kobject_init_and_add(&ext4_feat, &ext4_feat_ktype,
+	kobject_set_name(&ext4_kset->kobj, "ext4");
+	ext4_kset->kobj.parent = fs_kobj;
+	ext4_kset->kobj.ktype = &ext4_ktype;
+	ret = kset_register(ext4_kset);
+	if (ret)
+		goto kset_err;
+
+	ext4_feat = kzalloc(sizeof(*ext4_feat), GFP_KERNEL);
+	if (!ext4_feat) {
+		ret = -ENOMEM;
+		goto kset_err;
+	}
+
+	ext4_feat->kset = ext4_kset;
+	ret = kobject_init_and_add(ext4_feat, &ext4_feat_ktype,
 				   NULL, "features");
 	if (ret)
-		kset_unregister(&ext4_kset);
-	else
-		ext4_proc_root = proc_mkdir(proc_dirname, NULL);
+		goto feat_err;
+
+	ext4_proc_root = proc_mkdir(proc_dirname, NULL);
+	return ret;
+
+feat_err:
+	kobject_put(ext4_feat);
+kset_err:
+	kset_unregister(ext4_kset);
+	ext4_kset = NULL;
 	return ret;
 }
 
 void ext4_exit_sysfs(void)
 {
-	kobject_put(&ext4_feat);
-	kset_unregister(&ext4_kset);
+	kobject_put(ext4_feat);
+	kset_unregister(ext4_kset);
+	ext4_kset = NULL;
 	remove_proc_entry(proc_dirname, NULL);
 	ext4_proc_root = NULL;
 }

fs/ext4/truncate.h

···
-/* SPDX-License-Identifier: GPL-2.0 */
+// SPDX-License-Identifier: GPL-2.0
 /*
  * linux/fs/ext4/truncate.h
  *

fs/ext4/xattr.h

···
-/* SPDX-License-Identifier: GPL-2.0 */
+// SPDX-License-Identifier: GPL-2.0
 /*
   File: fs/ext4/xattr.h
 

fs/jbd2/checkpoint.c

···
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * linux/fs/jbd2/checkpoint.c
  *
  * Written by Stephen C. Tweedie <[e-mail]>, 1999
  *
  * Copyright 1999 Red Hat Software --- All Rights Reserved
- *
- * This file is part of the Linux kernel and is made available under
- * the terms of the GNU General Public License, version 2, or at your
- * option, any later version, incorporated herein by reference.
  *
  * Checkpoint routines for the generic filesystem journaling code.
  * Part of the ext2fs journaling system.

fs/jbd2/commit.c

···
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * linux/fs/jbd2/commit.c
  *
  * Written by Stephen C. Tweedie <[e-mail]>, 1998
  *
  * Copyright 1998 Red Hat corp --- All Rights Reserved
- *
- * This file is part of the Linux kernel and is made available under
- * the terms of the GNU General Public License, version 2, or at your
- * option, any later version, incorporated herein by reference.
  *
  * Journal commit routines for the generic filesystem journaling code;
  * part of the ext2fs journaling system.

fs/jbd2/journal.c

···
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * linux/fs/jbd2/journal.c
  *
  * Written by Stephen C. Tweedie <[e-mail]>, 1998
  *
  * Copyright 1998 Red Hat corp --- All Rights Reserved
- *
- * This file is part of the Linux kernel and is made available under
- * the terms of the GNU General Public License, version 2, or at your
- * option, any later version, incorporated herein by reference.
  *
  * Generic filesystem journal-writing code; part of the ext2fs
  * journaling system.

fs/jbd2/recovery.c

···
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * linux/fs/jbd2/recovery.c
  *
  * Written by Stephen C. Tweedie <[e-mail]>, 1999
  *
  * Copyright 1999-2000 Red Hat Software --- All Rights Reserved
- *
- * This file is part of the Linux kernel and is made available under
- * the terms of the GNU General Public License, version 2, or at your
- * option, any later version, incorporated herein by reference.
  *
  * Journal recovery routines for the generic filesystem journaling code;
  * part of the ext2fs journaling system.

fs/jbd2/revoke.c

···
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * linux/fs/jbd2/revoke.c
  *
  * Written by Stephen C. Tweedie <[e-mail]>, 2000
  *
  * Copyright 2000 Red Hat corp --- All Rights Reserved
- *
- * This file is part of the Linux kernel and is made available under
- * the terms of the GNU General Public License, version 2, or at your
- * option, any later version, incorporated herein by reference.
  *
  * Journal revoke routines for the generic filesystem journaling code;
  * part of the ext2fs journaling system.

fs/jbd2/transaction.c

···
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * linux/fs/jbd2/transaction.c
  *
  * Written by Stephen C. Tweedie <[e-mail]>, 1998
  *
  * Copyright 1998 Red Hat corp --- All Rights Reserved
- *
- * This file is part of the Linux kernel and is made available under
- * the terms of the GNU General Public License, version 2, or at your
- * option, any later version, incorporated herein by reference.
  *
  * Generic filesystem transaction handling code; part of the ext2fs
  * journaling system.
···
 EXPORT_SYMBOL(jbd2_journal_free_reserved);
 
 /**
- * int jbd2_journal_start_reserved(handle_t *handle) - start reserved handle
+ * int jbd2_journal_start_reserved() - start reserved handle
  * @handle: handle to start
+ * @type: for handle statistics
+ * @line_no: for handle statistics
  *
  * Start handle that has been previously reserved with jbd2_journal_reserve().
  * This attaches @handle to the running transaction (or creates one if there's
···
  * int jbd2_journal_restart() - restart a handle .
  * @handle:  handle to restart
  * @nblocks: nr credits requested
+ * @gfp_mask: memory allocation flags (for start_this_handle)
  *
  * Restart a handle for a multi-transaction filesystem
  * operation.

fs/mbcache.c

···
 	entry->e_key = key;
 	entry->e_value = value;
 	entry->e_reusable = reusable;
+	entry->e_referenced = 0;
 	head = mb_cache_entry_head(cache, key);
 	hlist_bl_lock(head);
 	hlist_bl_for_each_entry(dup, dup_node, head, e_hash_list) {
···
 			spin_lock(&cache->c_list_lock);
 			if (!list_empty(&entry->e_list)) {
 				list_del_init(&entry->e_list);
-				cache->c_entry_count--;
+				if (!WARN_ONCE(cache->c_entry_count == 0,
+		"mbcache: attempt to decrement c_entry_count past zero"))
+					cache->c_entry_count--;
 				atomic_dec(&entry->e_refcnt);
 			}
 			spin_unlock(&cache->c_list_lock);
···
 	struct mb_cache *cache = container_of(shrink, struct mb_cache,
 					      c_shrink);
 
-	/* Unlikely, but not impossible */
-	if (unlikely(cache->c_entry_count < 0))
-		return 0;
 	return cache->c_entry_count;
 }
 

fs/xfs/xfs_file.c

···
 	if (IS_DAX(inode)) {
 		pfn_t pfn;
 
-		ret = dax_iomap_fault(vmf, pe_size, &pfn, &xfs_iomap_ops);
+		ret = dax_iomap_fault(vmf, pe_size, &pfn, NULL, &xfs_iomap_ops);
 		if (ret & VM_FAULT_NEEDDSYNC)
 			ret = dax_finish_sync_fault(vmf, pe_size, pfn);
 	} else {

include/linux/dax.h

···
 ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
 		const struct iomap_ops *ops);
 int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
-		    pfn_t *pfnp, const struct iomap_ops *ops);
+		    pfn_t *pfnp, int *errp, const struct iomap_ops *ops);
 int dax_finish_sync_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
 			  pfn_t pfn);
 int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);

include/linux/jbd2.h

···
 #define JI_WAIT_DATA (1 << __JI_WAIT_DATA)
 
 /**
- * struct jbd_inode is the structure linking inodes in ordered mode
- *   present in a transaction so that we can sync them during commit.
+ * struct jbd_inode - The jbd_inode type is the structure linking inodes in
+ * ordered mode present in a transaction so that we can sync them during commit.
  */
 struct jbd2_inode {
-	/* Which transaction does this inode belong to? Either the running
-	 * transaction or the committing one. [j_list_lock] */
+	/**
+	 * @i_transaction:
+	 *
+	 * Which transaction does this inode belong to? Either the running
+	 * transaction or the committing one. [j_list_lock]
+	 */
 	transaction_t *i_transaction;
 
-	/* Pointer to the running transaction modifying inode's data in case
-	 * there is already a committing transaction touching it. [j_list_lock] */
+	/**
+	 * @i_next_transaction:
+	 *
+	 * Pointer to the running transaction modifying inode's data in case
+	 * there is already a committing transaction touching it. [j_list_lock]
+	 */
 	transaction_t *i_next_transaction;
 
-	/* List of inodes in the i_transaction [j_list_lock] */
+	/**
+	 * @i_list: List of inodes in the i_transaction [j_list_lock]
+	 */
 	struct list_head i_list;
 
-	/* VFS inode this inode belongs to [constant during the lifetime
-	 * of the structure] */
+	/**
+	 * @i_vfs_inode:
+	 *
+	 * VFS inode this inode belongs to [constant for lifetime of structure]
+	 */
 	struct inode *i_vfs_inode;
 
-	/* Flags of inode [j_list_lock] */
+	/**
+	 * @i_flags: Flags of inode [j_list_lock]
+	 */
 	unsigned long i_flags;
 };
 
···
  * struct handle_s - The handle_s type is the concrete type associated with
  *     handle_t.
  * @h_transaction: Which compound transaction is this update a part of?
+ * @h_journal: Which journal handle belongs to - used iff h_reserved set.
+ * @h_rsv_handle: Handle reserved for finishing the logical operation.
  * @h_buffer_credits: Number of remaining buffers we are allowed to dirty.
- * @h_ref: Reference count on this handle
- * @h_err: Field for caller's use to track errors through large fs operations
- * @h_sync: flag for sync-on-close
- * @h_jdata: flag to force data journaling
- * @h_aborted: flag indicating fatal error on handle
+ * @h_ref: Reference count on this handle.
+ * @h_err: Field for caller's use to track errors through large fs operations.
+ * @h_sync: Flag for sync-on-close.
+ * @h_jdata: Flag to force data journaling.
+ * @h_reserved: Flag for handle for reserved credits.
+ * @h_aborted: Flag indicating fatal error on handle.
+ * @h_type: For handle statistics.
+ * @h_line_no: For handle statistics.
+ * @h_start_jiffies: Handle Start time.
+ * @h_requested_credits: Holds @h_buffer_credits after handle is started.
+ * @saved_alloc_context: Saved context while transaction is open.
  **/
 
 /* Docbook can't yet cope with the bit fields, but will leave the documentation
···
 struct jbd2_journal_handle
 {
 	union {
-		/* Which compound transaction is this update a part of? */
 		transaction_t	*h_transaction;
 		/* Which journal handle belongs to - used iff h_reserved set */
 		journal_t	*h_journal;
 	};
 
-	/* Handle reserved for finishing the logical operation */
 	handle_t		*h_rsv_handle;
-
-	/* Number of remaining buffers we are allowed to dirty: */
 	int			h_buffer_credits;
-
-	/* Reference count on this handle */
 	int			h_ref;
-
-	/* Field for caller's use to track errors through large fs */
-	/* operations */
 	int			h_err;
 
 	/* Flags [no locking] */
-	unsigned int	h_sync:		1;	/* sync-on-close */
-	unsigned int	h_jdata:	1;	/* force data journaling */
-	unsigned int	h_reserved:	1;	/* handle with reserved credits */
-	unsigned int	h_aborted:	1;	/* fatal error on handle */
-	unsigned int	h_type:		8;	/* for handle statistics */
-	unsigned int	h_line_no:	16;	/* for handle statistics */
+	unsigned int	h_sync:		1;
+	unsigned int	h_jdata:	1;
+	unsigned int	h_reserved:	1;
+	unsigned int	h_aborted:	1;
+	unsigned int	h_type:		8;
+	unsigned int	h_line_no:	16;
 
 	unsigned long		h_start_jiffies;
 	unsigned int		h_requested_credits;
···
 /**
  * struct journal_s - The journal_s type is the concrete type associated with
  *     journal_t.
- * @j_flags:  General journaling state flags
- * @j_errno:  Is there an outstanding uncleared error on the journal (from a
- *     prior abort)?
- * @j_sb_buffer: First part of superblock buffer
- * @j_superblock: Second part of superblock buffer
- * @j_format_version: Version of the superblock format
- * @j_state_lock: Protect the various scalars in the journal
- * @j_barrier_count:  Number of processes waiting to create a barrier lock
- * @j_barrier: The barrier lock itself
- * @j_running_transaction: The current running transaction..
- * @j_committing_transaction: the transaction we are pushing to disk
- * @j_checkpoint_transactions: a linked circular list of all transactions
- *  waiting for checkpointing
- * @j_wait_transaction_locked: Wait queue for waiting for a locked transaction
- *  to start committing, or for a barrier lock to be released
- * @j_wait_done_commit: Wait queue for waiting for commit to complete
- * @j_wait_commit: Wait queue to trigger commit
- * @j_wait_updates: Wait queue to wait for updates to complete
- * @j_wait_reserved: Wait queue to wait for reserved buffer credits to drop
- * @j_checkpoint_mutex: Mutex for locking against concurrent checkpoints
- * @j_head: Journal head - identifies the first unused block in the journal
- * @j_tail: Journal tail - identifies the oldest still-used block in the
- *  journal.
- * @j_free: Journal free - how many free blocks are there in the journal?
- * @j_first: The block number of the first usable block
- * @j_last: The block number one beyond the last usable block
- * @j_dev: Device where we store the journal
- * @j_blocksize: blocksize for the location where we store the journal.
- * @j_blk_offset: starting block offset for into the device where we store the
- *     journal
- * @j_fs_dev: Device which holds the client fs.  For internal journal this will
- *     be equal to j_dev
- * @j_reserved_credits: Number of buffers reserved from the running transaction
- * @j_maxlen: Total maximum capacity of the journal region on disk.
- * @j_list_lock: Protects the buffer lists and internal buffer state.
- * @j_inode: Optional inode where we store the journal.  If present, all journal
- *     block numbers are mapped into this inode via bmap().
- * @j_tail_sequence:  Sequence number of the oldest transaction in the log
- * @j_transaction_sequence: Sequence number of the next transaction to grant
- * @j_commit_sequence: Sequence number of the most recently committed
- *  transaction
- * @j_commit_request: Sequence number of the most recent transaction wanting
- *     commit
- * @j_uuid: Uuid of client object.
- * @j_task: Pointer to the current commit thread for this journal
- * @j_max_transaction_buffers:  Maximum number of metadata buffers to allow in a
- *     single compound commit transaction
- * @j_commit_interval: What is the maximum transaction lifetime before we begin
- *  a commit?
- * @j_commit_timer:  The timer used to wakeup the commit thread
- * @j_revoke_lock: Protect the revoke table
- * @j_revoke: The revoke table - maintains the list of revoked blocks in the
- *     current transaction.
- * @j_revoke_table: alternate revoke tables for j_revoke
- * @j_wbuf: array of buffer_heads for jbd2_journal_commit_transaction
- * @j_wbufsize: maximum number of buffer_heads allowed in j_wbuf, the
- *	number that will fit in j_blocksize
- * @j_last_sync_writer: most recent pid which did a synchronous write
- * @j_history_lock: Protect the transactions statistics history
- * @j_proc_entry: procfs entry for the jbd statistics directory
- * @j_stats: Overall statistics
- * @j_private: An opaque pointer to fs-private information.
- * @j_trans_commit_map: Lockdep entity to track transaction commit dependencies
  */
-
 struct journal_s
 {
-	/* General journaling state flags [j_state_lock] */
+	/**
+	 * @j_flags: General journaling state flags [j_state_lock]
+	 */
 	unsigned long		j_flags;
 
-	/*
+	/**
+	 * @j_errno:
+	 *
 	 * Is there an outstanding uncleared error on the journal (from a prior
 	 * abort)? [j_state_lock]
 	 */
 	int			j_errno;
 
-	/* The superblock buffer */
+	/**
+	 * @j_sb_buffer: The first part of the superblock buffer.
+	 */
 	struct buffer_head	*j_sb_buffer;
+
+	/**
+	 * @j_superblock: The second part of the superblock buffer.
+	 */
 	journal_superblock_t	*j_superblock;
 
-	/* Version of the superblock format */
+	/**
+	 * @j_format_version: Version of the superblock format.
+	 */
 	int			j_format_version;
 
-	/*
-	 * Protect the various scalars in the journal
+	/**
+	 * @j_state_lock: Protect the various scalars in the journal.
 	 */
 	rwlock_t		j_state_lock;
 
-	/*
+	/**
+	 * @j_barrier_count:
+	 *
 	 * Number of processes waiting to create a barrier lock [j_state_lock]
 	 */
 	int			j_barrier_count;
 
-	/* The barrier lock itself */
+	/**
+	 * @j_barrier: The barrier lock itself.
+	 */
 	struct mutex		j_barrier;
 
-	/*
+	/**
+	 * @j_running_transaction:
+	 *
 	 * Transactions: The current running transaction...
 	 * [j_state_lock] [caller holding open handle]
 	 */
 	transaction_t		*j_running_transaction;
 
-	/*
+	/**
+	 * @j_committing_transaction:
+	 *
 	 * the transaction we are pushing to disk
 	 * [j_state_lock] [caller holding open handle]
 	 */
 	transaction_t		*j_committing_transaction;
 
-	/*
+	/**
+	 * @j_checkpoint_transactions:
+	 *
 	 * ... and a linked circular list of all transactions waiting for
 	 * checkpointing. [j_list_lock]
 	 */
 	transaction_t		*j_checkpoint_transactions;
 
-	/*
+	/**
+	 * @j_wait_transaction_locked:
+	 *
 	 * Wait queue for waiting for a locked transaction to start committing,
-	 * or for a barrier lock to be released
+	 * or for a barrier lock to be released.
 	 */
 	wait_queue_head_t	j_wait_transaction_locked;
 
-	/* Wait queue for waiting for commit to complete */
+	/**
+	 * @j_wait_done_commit: Wait queue for waiting for commit to complete.
+	 */
 	wait_queue_head_t	j_wait_done_commit;
 
-	/* Wait queue to trigger commit */
+	/**
+	 * @j_wait_commit: Wait queue to trigger commit.
+	 */
 	wait_queue_head_t	j_wait_commit;
 
-	/* Wait queue to wait for updates to complete */
+	/**
+	 * @j_wait_updates: Wait queue to wait for updates to complete.
+	 */
 	wait_queue_head_t	j_wait_updates;
 
-	/* Wait queue to wait for reserved buffer credits to drop */
+	/**
+	 * @j_wait_reserved:
+	 *
+	 * Wait queue to wait for reserved buffer credits to drop.
+	 */
 	wait_queue_head_t	j_wait_reserved;
 
-	/* Semaphore for locking against concurrent checkpoints */
+	/**
+	 * @j_checkpoint_mutex:
+	 *
+	 * Semaphore for locking against concurrent checkpoints.
+	 */
 	struct mutex		j_checkpoint_mutex;
 
-	/*
+	/**
+	 * @j_chkpt_bhs:
+	 *
 	 * List of buffer heads used by the checkpoint routine.  This
 	 * was moved from jbd2_log_do_checkpoint() to reduce stack
 	 * usage.  Access to this array is controlled by the
-	 * j_checkpoint_mutex.  [j_checkpoint_mutex]
+	 * @j_checkpoint_mutex.  [j_checkpoint_mutex]
 	 */
 	struct buffer_head	*j_chkpt_bhs[JBD2_NR_BATCH];
-	
-	/*
+
+	/**
+	 * @j_head:
+	 *
 	 * Journal head: identifies the first unused block in the journal.
 	 * [j_state_lock]
 	 */
 	unsigned long		j_head;
 
-	/*
+	/**
+	 * @j_tail:
+	 *
 	 * Journal tail: identifies the oldest still-used block in the journal.
 	 * [j_state_lock]
 	 */
 	unsigned long		j_tail;
 
-	/*
+	/**
+	 * @j_free:
+	 *
 	 * Journal free: how many free blocks are there in the journal?
 	 * [j_state_lock]
 	 */
 	unsigned long		j_free;
 
-	/*
-	 * Journal start and end: the block numbers of the first usable block
-	 * and one beyond the last usable block in the journal. [j_state_lock]
+	/**
+	 * @j_first:
+	 *
+	 * The block number of the first usable block in the journal
+	 * [j_state_lock].
 	 */
 	unsigned long		j_first;
+
+	/**
+	 * @j_last:
+	 *
+	 * The block number one beyond the last usable block in the journal
+	 * [j_state_lock].
+	 */
 	unsigned long		j_last;
 
-	/*
-	 * Device, blocksize and starting block offset for the location where we
-	 * store the journal.
+	/**
+	 * @j_dev: Device where we store the journal.
 	 */
 	struct block_device	*j_dev;
+
+	/**
+	 * @j_blocksize: Block size for the location where we store the journal.
+	 */
 	int			j_blocksize;
+
+	/**
+	 * @j_blk_offset:
+	 *
+	 * Starting block offset into the device where we store the journal.
+	 */
 	unsigned long long	j_blk_offset;
+
+	/**
+	 * @j_devname: Journal device name.
+	 */
 	char			j_devname[BDEVNAME_SIZE+24];
 
-	/*
+	/**
+	 * @j_fs_dev:
+	 *
 	 * Device which holds the client fs.  For internal journal this will be
 	 * equal to j_dev.
 	 */
 	struct block_device	*j_fs_dev;
 
-	/* Total maximum capacity of the journal region on disk. */
+	/**
+	 * @j_maxlen: Total maximum capacity of the journal region on disk.
+	 */
 	unsigned int		j_maxlen;
 
-	/* Number of buffers reserved from the running transaction */
+	/**
+	 * @j_reserved_credits:
+	 *
+	 * Number of buffers reserved from the running transaction.
+	 */
 	atomic_t		j_reserved_credits;
 
-	/*
-	 * Protects the buffer lists and internal buffer state.
+	/**
+	 * @j_list_lock: Protects the buffer lists and internal buffer state.
 	 */
 	spinlock_t		j_list_lock;
 
-	/* Optional inode where we store the journal.  If present, all */
-	/* journal block numbers are mapped into this inode via */
-	/* bmap(). */
+	/**
+	 * @j_inode:
+	 *
+	 * Optional inode where we store the journal.  If present, all
+	 * journal block numbers are mapped into this inode via bmap().
+	 */
 	struct inode		*j_inode;
 
-	/*
+	/**
+	 * @j_tail_sequence:
+	 *
 	 * Sequence number of the oldest transaction in the log [j_state_lock]
 	 */
 	tid_t			j_tail_sequence;
 
-	/*
+	/**
+	 * @j_transaction_sequence:
+	 *
 	 * Sequence number of the next transaction to grant [j_state_lock]
 	 */
 	tid_t			j_transaction_sequence;
 
-	/*
+	/**
+	 * @j_commit_sequence:
+	 *
 	 * Sequence number of the most recently committed transaction
 	 * [j_state_lock].
 	 */
 	tid_t			j_commit_sequence;
 
-	/*
+	/**
+	 * @j_commit_request:
+	 *
 	 * Sequence number of the most recent transaction wanting commit
 	 * [j_state_lock]
 	 */
 	tid_t			j_commit_request;
 
-	/*
+	/**
+	 * @j_uuid:
+	 *
 	 * Journal uuid: identifies the object (filesystem, LVM volume etc)
 	 * backed by this journal.  This will eventually be replaced by an array
 	 * of uuids, allowing us to index multiple devices within a single
···
 	 */
 	__u8			j_uuid[16];
 
-	/* Pointer to the current commit thread for this journal */
+	/**
+	 * @j_task: Pointer to the current commit thread for this journal.
+	 */
 	struct task_struct	*j_task;
 
-	/*
+	/**
+	 * @j_max_transaction_buffers:
+	 *
 	 * Maximum number of metadata buffers to allow in a single compound
-	 * commit transaction
+	 * commit transaction.
 	 */
 	int			j_max_transaction_buffers;
 
-	/*
+	/**
+	 * @j_commit_interval:
+	 *
 	 * What is the maximum transaction lifetime before we begin a commit?
 	 */
 	unsigned long		j_commit_interval;
 
-	/* The timer used to wakeup the commit thread: */
+	/**
+	 * @j_commit_timer: The timer used to wakeup the commit thread.
+	 */
 	struct timer_list	j_commit_timer;
 
-	/*
-	 * The revoke table: maintains the list of revoked blocks in the
-	 * current transaction.  [j_revoke_lock]
+	/**
+	 * @j_revoke_lock: Protect the revoke table.
 	 */
 	spinlock_t		j_revoke_lock;
+
+	/**
+	 * @j_revoke:
+	 *
+	 * The revoke table - maintains the list of revoked blocks in the
+	 * current transaction.
+	 */
 	struct jbd2_revoke_table_s *j_revoke;
+
+	/**
+	 * @j_revoke_table: Alternate revoke tables for j_revoke.
+	 */
 	struct jbd2_revoke_table_s *j_revoke_table[2];
 
-	/*
-	 * array of bhs for jbd2_journal_commit_transaction
+	/**
+	 * @j_wbuf: Array of bhs for jbd2_journal_commit_transaction.
 	 */
 	struct buffer_head	**j_wbuf;
+
+	/**
+	 * @j_wbufsize:
+	 *
+	 * Size of @j_wbuf array.
+	 */
 	int			j_wbufsize;
 
-	/*
-	 * this is the pid of hte last person to run a synchronous operation
-	 * through the journal
+	/**
+	 * @j_last_sync_writer:
+	 *
+	 * The pid of the last person to run a synchronous operation
+	 * through the journal.
 	 */
 	pid_t			j_last_sync_writer;
 
-	/*
-	 * the average amount of time in nanoseconds it takes to commit a
+	/**
+	 * @j_average_commit_time:
+	 *
+	 * The average amount of time in nanoseconds it takes to commit a
 	 * transaction to disk. [j_state_lock]
 	 */
 	u64			j_average_commit_time;
 
-	/*
-	 * minimum and maximum times that we should wait for
-	 * additional filesystem operations to get batched into a
-	 * synchronous handle in microseconds
+	/**
+	 * @j_min_batch_time:
+	 *
+	 * Minimum time that we should wait for additional filesystem operations
+	 * to get batched into a synchronous handle in microseconds.
 	 */
 	u32			j_min_batch_time;
+
+	/**
+	 * @j_max_batch_time:
+	 *
+	 * Maximum time that we should wait for additional filesystem operations
+	 * to get batched into a synchronous handle in microseconds.
+	 */
 	u32			j_max_batch_time;
 
-	/* This function is called when a transaction is closed */
+	/**
+	 * @j_commit_callback:
+	 *
+	 * This function is called when a transaction is closed.
+	 */
 	void			(*j_commit_callback)(journal_t *,
 						     transaction_t *);
 
 	/*
 	 * Journal statistics
 	 */
+
+	/**
+	 * @j_history_lock: Protect the transactions statistics history.
+	 */
 	spinlock_t		j_history_lock;
+
+	/**
+	 * @j_proc_entry: procfs entry for the jbd statistics directory.
+	 */
 	struct proc_dir_entry	*j_proc_entry;
+
+	/**
+	 * @j_stats: Overall statistics.
+	 */
 	struct transaction_stats_s j_stats;
 
-	/* Failed journal commit ID */
+	/**
+	 * @j_failed_commit: Failed journal commit ID.
+	 */
 	unsigned int		j_failed_commit;
 
-	/*
+	/**
+	 * @j_private:
+	 *
 	 * An opaque pointer to fs-private information.  ext3 puts its
-	 * superblock pointer here
+	 * superblock pointer here.
 	 */
 	void *j_private;
 
-	/* Reference to checksum algorithm driver via cryptoapi */
+	/**
+	 * @j_chksum_driver:
+	 *
+	 * Reference to checksum algorithm driver via cryptoapi.
+	 */
 	struct crypto_shash *j_chksum_driver;
 
-	/* Precomputed journal UUID checksum for seeding other checksums */
+	/**
+	 * @j_csum_seed:
+	 *
+	 * Precomputed journal UUID checksum for seeding other checksums.
+	 */
 	__u32 j_csum_seed;
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
-	/*
+	/**
+	 * @j_trans_commit_map:
+	 *
 	 * Lockdep entity to track transaction commit dependencies. Handles
 	 * hold this "lock" for read, when we wait for commit, we acquire the
 	 * "lock" for writing. This matches the properties of jbd2 journalling