Track metadata bhs for an inode in fs-private part of the inode.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/fat/fat.h         |  2 ++
 fs/fat/file.c        |  1 +
 fs/fat/inode.c       | 12 ++++++++++++
 fs/fat/namei_msdos.c |  1 +
 fs/fat/namei_vfat.c  |  1 +
 5 files changed, 17 insertions(+)

diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index 0d269dba897b..2b2f6ad32f24 100644
--- a/fs/fat/fat.h
+++ b/fs/fat/fat.h
@@ -130,6 +130,7 @@ struct msdos_inode_info {
 	struct hlist_node i_dir_hash;	/* hash by i_logstart */
 	struct rw_semaphore truncate_lock; /* protect bmap against truncate */
 	struct timespec64 i_crtime;	/* File creation (birth) time */
+	struct mapping_metadata_bhs i_metadata_bhs;
 	struct inode vfs_inode;
 };
 
@@ -424,6 +425,7 @@ extern int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de);
 
 extern int fat_flush_inodes(struct super_block *sb, struct inode *i1,
 			    struct inode *i2);
+struct mapping_metadata_bhs *fat_get_metadata_bhs(struct inode *inode);
 
 extern const struct fs_parameter_spec fat_param_spec[];
 int fat_init_fs_context(struct fs_context *fc, bool is_vfat);
diff --git a/fs/fat/file.c b/fs/fat/file.c
index 124d9c5431c8..da21636d3874 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -574,4 +574,5 @@ const struct inode_operations fat_file_inode_operations = {
 	.setattr	= fat_setattr,
 	.getattr	= fat_getattr,
 	.update_time	= fat_update_time,
+	.get_metadata_bhs = fat_get_metadata_bhs,
 };
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index ce88602b0d57..8561b8be5ca2 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -763,6 +763,7 @@ static struct inode *fat_alloc_inode(struct super_block *sb)
 	ei->i_pos = 0;
 	ei->i_crtime.tv_sec = 0;
 	ei->i_crtime.tv_nsec = 0;
+	mmb_init(&ei->i_metadata_bhs);
 
 	return &ei->vfs_inode;
 }
@@ -807,6 +808,12 @@ static void __exit fat_destroy_inodecache(void)
 	kmem_cache_destroy(fat_inode_cachep);
 }
 
+struct mapping_metadata_bhs *fat_get_metadata_bhs(struct inode *inode)
+{
+	return &MSDOS_I(inode)->i_metadata_bhs;
+}
+EXPORT_SYMBOL_GPL(fat_get_metadata_bhs);
+
 int fat_reconfigure(struct fs_context *fc)
 {
 	bool new_rdonly;
@@ -1531,6 +1538,10 @@ static int fat_read_static_bpb(struct super_block *sb,
 	return error;
 }
 
+static const struct inode_operations fat_table_inode_operations = {
+	.get_metadata_bhs = fat_get_metadata_bhs,
+};
+
 /*
  * Read the super block of an MS-DOS FS.
  */
@@ -1806,6 +1817,7 @@ int fat_fill_super(struct super_block *sb, struct fs_context *fc,
 	fat_inode = new_inode(sb);
 	if (!fat_inode)
 		goto out_fail;
+	fat_inode->i_op = &fat_table_inode_operations;
 	sbi->fat_inode = fat_inode;
 
 	fsinfo_inode = new_inode(sb);
diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c
index 048c103b506a..1526b8910d51 100644
--- a/fs/fat/namei_msdos.c
+++ b/fs/fat/namei_msdos.c
@@ -643,6 +643,7 @@ static const struct inode_operations msdos_dir_inode_operations = {
 	.setattr	= fat_setattr,
 	.getattr	= fat_getattr,
 	.update_time	= fat_update_time,
+	.get_metadata_bhs = fat_get_metadata_bhs,
 };
 
 static void setup(struct super_block *sb)
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
index 87dcdd86272b..ca5e0e9822a6 100644
--- a/fs/fat/namei_vfat.c
+++ b/fs/fat/namei_vfat.c
@@ -1186,6 +1186,7 @@ static const struct inode_operations vfat_dir_inode_operations = {
 	.setattr	= fat_setattr,
 	.getattr	= fat_getattr,
 	.update_time	= fat_update_time,
+	.get_metadata_bhs = fat_get_metadata_bhs,
 };
 
 static void setup(struct super_block *sb)
-- 
2.51.0