[PATCH 35/49] ext4: Add inode version support in ext4

From: Theodore Ts'o
Date: Mon Jan 21 2008 - 22:21:29 EST


From: Jean Noel Cordenner <jean-noel.cordenner@xxxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: Andreas Dilger <adilger@xxxxxxxxxxxxx>
Signed-off-by: Kalpak Shah <kalpak@xxxxxxxxxxxxx>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Jean Noel Cordenner <jean-noel.cordenner@xxxxxxxx>
---
fs/ext4/inode.c | 18 +++++++++++++++++-
fs/ext4/super.c | 10 ++++++++--
fs/inode.c | 17 -----------------
include/linux/ext4_fs.h | 6 +++++-
include/linux/fs.h | 16 +++++++++++++++-
5 files changed, 45 insertions(+), 22 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index ee0bc3a..3c013e5 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2780,6 +2780,13 @@ void ext4_read_inode(struct inode * inode)
EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode);
EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);

+ inode->i_version = le32_to_cpu(raw_inode->i_disk_version);
+ if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
+ if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
+ inode->i_version |=
+ (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
+ }
+
if (S_ISREG(inode->i_mode)) {
inode->i_op = &ext4_file_inode_operations;
inode->i_fop = &ext4_file_operations;
@@ -2962,8 +2969,14 @@ static int ext4_do_update_inode(handle_t *handle,
} else for (block = 0; block < EXT4_N_BLOCKS; block++)
raw_inode->i_block[block] = ei->i_data[block];

- if (ei->i_extra_isize)
+ raw_inode->i_disk_version = cpu_to_le32(inode->i_version);
+ if (ei->i_extra_isize) {
+ if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
+ raw_inode->i_version_hi =
+ cpu_to_le32(inode->i_version >> 32);
raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
+ }
+

BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata");
rc = ext4_journal_dirty_metadata(handle, bh);
@@ -3190,6 +3203,9 @@ int ext4_mark_iloc_dirty(handle_t *handle,
{
int err = 0;

+ if (test_opt(inode->i_sb, I_VERSION))
+ inode_inc_iversion(inode);
+
/* the do_update_inode consumes one bh->b_count */
get_bh(iloc->bh);

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index f7479d3..aa22acd 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -732,6 +732,8 @@ static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
seq_puts(seq, ",nobh");
if (!test_opt(sb, EXTENTS))
seq_puts(seq, ",noextents");
+ if (test_opt(sb, I_VERSION))
+ seq_puts(seq, ",i_version");

if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
seq_puts(seq, ",data=journal");
@@ -874,7 +876,7 @@ enum {
Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
- Opt_grpquota, Opt_extents, Opt_noextents,
+ Opt_grpquota, Opt_extents, Opt_noextents, Opt_i_version,
};

static match_table_t tokens = {
@@ -928,6 +930,7 @@ static match_table_t tokens = {
{Opt_barrier, "barrier=%u"},
{Opt_extents, "extents"},
{Opt_noextents, "noextents"},
+ {Opt_i_version, "i_version"},
{Opt_err, NULL},
{Opt_resize, "resize"},
};
@@ -1273,6 +1276,10 @@ clear_qf_name:
case Opt_noextents:
clear_opt (sbi->s_mount_opt, EXTENTS);
break;
+ case Opt_i_version:
+ set_opt(sbi->s_mount_opt, I_VERSION);
+ sb->s_flags |= MS_I_VERSION;
+ break;
default:
printk (KERN_ERR
"EXT4-fs: Unrecognized mount option \"%s\" "
@@ -3197,7 +3204,6 @@ out:
i_size_write(inode, off+len-towrite);
EXT4_I(inode)->i_disksize = inode->i_size;
}
- inode->i_version++;
inode->i_mtime = inode->i_ctime = CURRENT_TIME;
ext4_mark_inode_dirty(handle, inode);
mutex_unlock(&inode->i_mutex);
diff --git a/fs/inode.c b/fs/inode.c
index b48324a..276ffd6 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1243,23 +1243,6 @@ void touch_atime(struct vfsmount *mnt, struct dentry *dentry)
EXPORT_SYMBOL(touch_atime);

/**
- * 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
- *
- */
-
-void inode_inc_iversion(struct inode *inode)
-{
- spin_lock(&inode->i_lock);
- inode->i_version++;
- spin_unlock(&inode->i_lock);
-}
-
-/**
* file_update_time - update mtime and ctime time
* @file: file accessed
*
diff --git a/include/linux/ext4_fs.h b/include/linux/ext4_fs.h
index cd406db..b609294 100644
--- a/include/linux/ext4_fs.h
+++ b/include/linux/ext4_fs.h
@@ -292,7 +292,7 @@ struct ext4_inode {
__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 @@ struct ext4_inode {
__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 @@ do { \
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 @@ do { \
#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 94cf5d8..2ac81ee 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1396,7 +1396,21 @@ static inline void inode_dec_link_count(struct inode *inode)
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)
{
--
1.5.4.rc3.31.g1271-dirty

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