ext4: Add inode version support in ext4
This patch adds 64-bit inode version support to ext4. The lower 32 bits
are stored in the osd1.linux1.l_i_version field while the high 32 bits
are stored in the i_version_hi field newly created in the ext4_inode.
This field is incremented in case the ext4_inode is large enough. A
i_version mount option has been added to enable the feature.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Andreas Dilger <adilger@clusterfs.com>
Signed-off-by: Kalpak Shah <kalpak@clusterfs.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Jean Noel Cordenner <jean-noel.cordenner@bull.net>
diff --git a/include/linux/ext4_fs.h b/include/linux/ext4_fs.h
index cd406db..b6092940 100644
--- a/include/linux/ext4_fs.h
+++ b/include/linux/ext4_fs.h
@@ -292,7 +292,7 @@
__le32 i_flags; /* File flags */
union {
struct {
- __u32 l_i_reserved1;
+ __le32 l_i_version;
} linux1;
struct {
__u32 h_i_translator;
@@ -334,6 +334,7 @@
__le32 i_atime_extra; /* extra Access time (nsec << 2 | epoch) */
__le32 i_crtime; /* File Creation time */
__le32 i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
+ __le32 i_version_hi; /* high 32 bits for 64-bit version */
};
@@ -407,6 +408,8 @@
raw_inode->xtime ## _extra); \
} while (0)
+#define i_disk_version osd1.linux1.l_i_version
+
#if defined(__KERNEL__) || defined(__linux__)
#define i_reserved1 osd1.linux1.l_i_reserved1
#define i_file_acl_high osd2.linux2.l_i_file_acl_high
@@ -469,6 +472,7 @@
#define EXT4_MOUNT_EXTENTS 0x400000 /* Extents support */
#define EXT4_MOUNT_JOURNAL_CHECKSUM 0x800000 /* Journal checksums */
#define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT 0x1000000 /* Journal Async Commit */
+#define EXT4_MOUNT_I_VERSION 0x2000000 /* i_version support */
/* Compatibility, for having both ext2_fs.h and ext4_fs.h included at once */
#ifndef _LINUX_EXT2_FS_H
#define clear_opt(o, opt) o &= ~EXT4_MOUNT_##opt
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 9608839..a516b67 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1396,7 +1396,21 @@
mark_inode_dirty(inode);
}
-extern void inode_inc_iversion(struct inode *inode);
+/**
+ * inode_inc_iversion - increments i_version
+ * @inode: inode that need to be updated
+ *
+ * Every time the inode is modified, the i_version field will be incremented.
+ * The filesystem has to be mounted with i_version flag
+ */
+
+static inline void inode_inc_iversion(struct inode *inode)
+{
+ spin_lock(&inode->i_lock);
+ inode->i_version++;
+ spin_unlock(&inode->i_lock);
+}
+
extern void touch_atime(struct vfsmount *mnt, struct dentry *dentry);
static inline void file_accessed(struct file *file)
{