fs: new API for handling inode->i_version
Add a documentation blob that explains what the i_version field is, how
it is expected to work, and how it is currently implemented by various
filesystems.
We already have inode_inc_iversion. Add several other functions for
manipulating and accessing the i_version counter. For now, the
implementation is trivial and basically works the way that all of the
open-coded i_version accesses work today.
Future patches will convert existing users of i_version to use the new
API, and then convert the backend implementation to do things more
efficiently.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index eb1bac7..c95d7b2 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -31,6 +31,7 @@
#include <linux/slab.h>
#include <linux/btrfs.h>
#include <linux/uio.h>
+#include <linux/iversion.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index e1a7f3c..27f008b 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -43,6 +43,7 @@
#include <linux/posix_acl_xattr.h>
#include <linux/uio.h>
#include <linux/magic.h>
+#include <linux/iversion.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 2ef8aca..aa452c9 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -43,6 +43,7 @@
#include <linux/uuid.h>
#include <linux/btrfs.h>
#include <linux/uaccess.h>
+#include <linux/iversion.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index 2c7e53f..5258c17 100644
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -23,6 +23,7 @@
#include <linux/xattr.h>
#include <linux/security.h>
#include <linux/posix_acl_xattr.h>
+#include <linux/iversion.h>
#include "ctree.h"
#include "btrfs_inode.h"
#include "transaction.h"
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 7df2c56..fa5d8bc 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -39,6 +39,7 @@
#include <linux/slab.h>
#include <linux/bitops.h>
#include <linux/iomap.h>
+#include <linux/iversion.h>
#include "ext4_jbd2.h"
#include "xattr.h"
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 798b3ac..bcf0dff 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -34,6 +34,7 @@
#include <linux/quotaops.h>
#include <linux/buffer_head.h>
#include <linux/bio.h>
+#include <linux/iversion.h>
#include "ext4.h"
#include "ext4_jbd2.h"
diff --git a/fs/inode.c b/fs/inode.c
index 03102d6..19e72f5 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -18,6 +18,7 @@
#include <linux/buffer_head.h> /* for inode_has_buffers */
#include <linux/ratelimit.h>
#include <linux/list_lru.h>
+#include <linux/iversion.h>
#include <trace/events/writeback.h>
#include "internal.h"