Add support for i_version

This adds i_version to our inode and maintains it as we allocate, load,
modify, and store inodes.  We set the flag in the superblock so
in-kernel users can use i_version to see changes in our inodes.

Signed-off-by: Zach Brown <zab@versity.com>

kmod/src/data.c

@@ -830,6 +830,7 @@ static int scoutfs_write_end(struct file *file, struct address_space *mapping,
 			scoutfs_inode_inc_data_version(inode);
 		}
 
+		inode_inc_iversion(inode);
 		scoutfs_update_inode_item(inode, wbd->lock, &wbd->ind_locks);
 		scoutfs_inode_queue_writeback(inode);
 	}
@@ -1033,6 +1034,7 @@ long scoutfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 				end = offset + len;
 			if (end > i_size_read(inode)) {
 				i_size_write(inode, end);
+				inode_inc_iversion(inode);
 				scoutfs_inode_inc_data_version(inode);
 			}
 		}
@@ -1366,10 +1368,12 @@ int scoutfs_data_move_blocks(struct inode *from, u64 from_off,
 		cur_time = CURRENT_TIME;
 		if (!is_stage) {
 			to->i_ctime = to->i_mtime = cur_time;
+			inode_inc_iversion(to);
 			scoutfs_inode_inc_data_version(to);
 			scoutfs_inode_set_data_seq(to);
 		}
 		from->i_ctime = from->i_mtime = cur_time;
+		inode_inc_iversion(from);
 		scoutfs_inode_inc_data_version(from);
 		scoutfs_inode_set_data_seq(from);
 

kmod/src/dir.c

@@ -836,6 +836,8 @@ static int scoutfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode,
 	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
 	inode->i_mtime = inode->i_atime = inode->i_ctime = dir->i_mtime;
 	si->crtime = inode->i_mtime;
+	inode_inc_iversion(dir);
+	inode_inc_iversion(inode);
 
 	if (S_ISDIR(mode)) {
 		inc_nlink(inode);
@@ -961,6 +963,8 @@ retry:
 	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
 	inode->i_ctime = dir->i_mtime;
 	inc_nlink(inode);
+	inode_inc_iversion(dir);
+	inode_inc_iversion(inode);
 
 	scoutfs_update_inode_item(inode, inode_lock, &ind_locks);
 	scoutfs_update_inode_item(dir, dir_lock, &ind_locks);
@@ -1058,6 +1062,8 @@ retry:
 	dir->i_ctime = ts;
 	dir->i_mtime = ts;
 	i_size_write(dir, i_size_read(dir) - dentry->d_name.len);
+	inode_inc_iversion(dir);
+	inode_inc_iversion(inode);
 
 	inode->i_ctime = ts;
 	drop_nlink(inode);
@@ -1295,10 +1301,12 @@ static int scoutfs_symlink(struct inode *dir, struct dentry *dentry,
 
 	i_size_write(dir, i_size_read(dir) + dentry->d_name.len);
 	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
+	inode_inc_iversion(dir);
 
 	inode->i_ctime = dir->i_mtime;
 	si->crtime = inode->i_ctime;
 	i_size_write(inode, name_len);
+	inode_inc_iversion(inode);
 
 	scoutfs_update_inode_item(inode, inode_lock, &ind_locks);
 	scoutfs_update_inode_item(dir, dir_lock, &ind_locks);
@@ -1779,6 +1787,13 @@ retry:
 	if (new_inode)
 		old_inode->i_ctime = now;
 
+	inode_inc_iversion(old_dir);
+	inode_inc_iversion(old_inode);
+	if (new_dir != old_dir)
+		inode_inc_iversion(new_dir);
+	if (new_inode)
+		inode_inc_iversion(new_inode);
+
 	scoutfs_update_inode_item(old_dir, old_dir_lock, &ind_locks);
 	scoutfs_update_inode_item(old_inode, old_inode_lock, &ind_locks);
 	if (new_dir != old_dir)
@@ -1888,6 +1903,7 @@ static int scoutfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mod
 	insert_inode_hash(inode);
 	ihold(inode); /* need to update inode modifications in d_tmpfile */
 	d_tmpfile(dentry, inode);
+	inode_inc_iversion(inode);
 
 	scoutfs_update_inode_item(inode, inode_lock, &ind_locks);
 	scoutfs_update_inode_item(dir, dir_lock, &ind_locks);

kmod/src/format.h

@@ -823,12 +823,6 @@ struct scoutfs_super_block {
  *
  * @offline_blocks: The number of fixed 4k blocks that could be made
  * online by staging.
- *
- * XXX
- *	- compat flags?
- *	- version?
- *	- generation?
- *	- be more careful with rdev?
  */
 struct scoutfs_inode {
 	__le64 size;
@@ -839,6 +833,7 @@ struct scoutfs_inode {
 	__le64 offline_blocks;
 	__le64 next_readdir_pos;
 	__le64 next_xattr_id;
+	__le64 version;
 	__le32 nlink;
 	__le32 uid;
 	__le32 gid;

kmod/src/inode.c

@@ -212,6 +212,7 @@ static void load_inode(struct inode *inode, struct scoutfs_inode *cinode)
 	struct scoutfs_inode_info *si = SCOUTFS_I(inode);
 
 	i_size_write(inode, le64_to_cpu(cinode->size));
+	inode->i_version = le64_to_cpu(cinode->version);
 	set_nlink(inode, le32_to_cpu(cinode->nlink));
 	i_uid_write(inode, le32_to_cpu(cinode->uid));
 	i_gid_write(inode, le32_to_cpu(cinode->gid));
@@ -346,6 +347,7 @@ static int set_inode_size(struct inode *inode, struct scoutfs_lock *lock,
 	if (truncate)
 		si->flags |= SCOUTFS_INO_FLAG_TRUNCATE;
 	scoutfs_inode_set_data_seq(inode);
+	inode_inc_iversion(inode);
 	scoutfs_update_inode_item(inode, lock, &ind_locks);
 
 	scoutfs_release_trans(sb);
@@ -481,6 +483,7 @@ retry:
 		goto out;
 
 	setattr_copy(inode, attr);
+	inode_inc_iversion(inode);
 	scoutfs_update_inode_item(inode, lock, &ind_locks);
 
 	scoutfs_release_trans(sb);
@@ -686,6 +689,7 @@ struct inode *scoutfs_iget(struct super_block *sb, u64 ino, int lkf)
 		/* XXX ensure refresh, instead clear in drop_inode? */
 		si = SCOUTFS_I(inode);
 		atomic64_set(&si->last_refreshed, 0);
+		inode->i_version = 0;
 
 		ret = scoutfs_inode_refresh(inode, lock, 0);
 		if (ret == 0)
@@ -713,6 +717,7 @@ static void store_inode(struct scoutfs_inode *cinode, struct inode *inode)
 	scoutfs_inode_get_onoff(inode, &online_blocks, &offline_blocks);
 
 	cinode->size = cpu_to_le64(i_size_read(inode));
+	cinode->version = cpu_to_le64(inode->i_version);
 	cinode->nlink = cpu_to_le32(inode->i_nlink);
 	cinode->uid = cpu_to_le32(i_uid_read(inode));
 	cinode->gid = cpu_to_le32(i_gid_read(inode));

kmod/src/super.c

@@ -545,6 +545,7 @@ static int scoutfs_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_maxbytes = MAX_LFS_FILESIZE;
 	sb->s_op = &scoutfs_super_ops;
 	sb->s_export_op = &scoutfs_export_ops;
+	sb->s_flags |= MS_I_VERSION;
 
 	/* btree blocks use long lived bh->b_data refs */
 	mapping_set_gfp_mask(sb->s_bdev->bd_inode->i_mapping, GFP_NOFS);

utils/src/print.c

@@ -47,13 +47,14 @@ static void print_inode(struct scoutfs_key *key, void *val, int val_len)
 {
 	struct scoutfs_inode *inode = val;
 
-	printf("    inode: ino %llu size %llu nlink %u\n"
+	printf("    inode: ino %llu size %llu version %llu nlink %u\n"
 	       "      uid %u gid %u mode 0%o rdev 0x%x flags 0x%x\n"
 	       "      next_readdir_pos %llu meta_seq %llu data_seq %llu data_version %llu\n"
 	       "      atime %llu.%08u ctime %llu.%08u\n"
 	       "      mtime %llu.%08u\n",
 	       le64_to_cpu(key->ski_ino),
 	       le64_to_cpu(inode->size),
+	       le64_to_cpu(inode->version),
 	       le32_to_cpu(inode->nlink), le32_to_cpu(inode->uid),
 	       le32_to_cpu(inode->gid), le32_to_cpu(inode->mode),
 	       le32_to_cpu(inode->rdev),