Commit 5beb6e0b authored by Ryusuke Konishi's avatar Ryusuke Konishi
Browse files

nilfs2: add bdev freeze/thaw support 



Nilfs hasn't supported the freeze/thaw feature because it didn't work
due to the peculiar design that multiple super block instances could
be allocated for a device.  This limitation was removed by the patch
"nilfs2: do not allocate multiple super block instances for a device".

So now this adds the freeze/thaw support to nilfs.

Signed-off-by: default avatarRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
parent c05dbfc2

fs/nilfs2/ioctl.c

+2 −0
Original line number Diff line number Diff line
@@ -580,6 +580,8 @@ static int nilfs_ioctl_clean_segments(struct inode *inode, struct file *filp, 
		goto out_free;

	}



	vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);



	ret = nilfs_ioctl_move_blocks(inode->i_sb, &argv[0], kbufs[0]);

	if (ret < 0)

		printk(KERN_ERR "NILFS: GC failed during preparation: "

fs/nilfs2/segment.c

+2 −0
Original line number Diff line number Diff line
@@ -191,6 +191,8 @@ int nilfs_transaction_begin(struct super_block *sb, 
	if (ret > 0)

		return 0;



	vfs_check_frozen(sb, SB_FREEZE_WRITE);



	sbi = NILFS_SB(sb);

	nilfs = sbi->s_nilfs;

	down_read(&nilfs->ns_segctor_sem);

fs/nilfs2/super.c

+54 −4
Original line number Diff line number Diff line
@@ -73,6 +73,7 @@ struct kmem_cache *nilfs_transaction_cachep; 
struct kmem_cache *nilfs_segbuf_cachep;

struct kmem_cache *nilfs_btree_path_cache;



static int nilfs_setup_super(struct nilfs_sb_info *sbi, int is_mount);

static int nilfs_remount(struct super_block *sb, int *flags, char *data);



static void nilfs_set_error(struct nilfs_sb_info *sbi)
@@ -439,6 +440,36 @@ int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno, int curr_mnt, 
	return err;

}



static int nilfs_freeze(struct super_block *sb)

{

	struct nilfs_sb_info *sbi = NILFS_SB(sb);

	struct the_nilfs *nilfs = sbi->s_nilfs;

	int err;



	if (sb->s_flags & MS_RDONLY)

		return 0;



	/* Mark super block clean */

	down_write(&nilfs->ns_sem);

	err = nilfs_cleanup_super(sbi);

	up_write(&nilfs->ns_sem);

	return err;

}



static int nilfs_unfreeze(struct super_block *sb)

{

	struct nilfs_sb_info *sbi = NILFS_SB(sb);

	struct the_nilfs *nilfs = sbi->s_nilfs;



	if (sb->s_flags & MS_RDONLY)

		return 0;



	down_write(&nilfs->ns_sem);

	nilfs_setup_super(sbi, false);

	up_write(&nilfs->ns_sem);

	return 0;

}



static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)

{

	struct super_block *sb = dentry->d_sb;
@@ -523,6 +554,8 @@ static const struct super_operations nilfs_sops = { 
	.put_super      = nilfs_put_super,

	/* .write_super    = nilfs_write_super, */

	.sync_fs        = nilfs_sync_fs,

	.freeze_fs	= nilfs_freeze,

	.unfreeze_fs	= nilfs_unfreeze,

	/* .write_super_lockfs */

	/* .unlockfs */

	.statfs         = nilfs_statfs,
@@ -626,7 +659,7 @@ nilfs_set_default_options(struct nilfs_sb_info *sbi, 
		NILFS_MOUNT_ERRORS_RO | NILFS_MOUNT_BARRIER;

}



static int nilfs_setup_super(struct nilfs_sb_info *sbi)

static int nilfs_setup_super(struct nilfs_sb_info *sbi, int is_mount)

{

	struct the_nilfs *nilfs = sbi->s_nilfs;

	struct nilfs_super_block **sbp;
@@ -638,6 +671,9 @@ static int nilfs_setup_super(struct nilfs_sb_info *sbi) 
	if (!sbp)

		return -EIO;



	if (!is_mount)

		goto skip_mount_setup;



	max_mnt_count = le16_to_cpu(sbp[0]->s_max_mnt_count);

	mnt_count = le16_to_cpu(sbp[0]->s_mnt_count);
@@ -654,9 +690,11 @@ static int nilfs_setup_super(struct nilfs_sb_info *sbi) 
		sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);



	sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);

	sbp[0]->s_mtime = cpu_to_le64(get_seconds());



skip_mount_setup:

	sbp[0]->s_state =

		cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);

	sbp[0]->s_mtime = cpu_to_le64(get_seconds());

	/* synchronize sbp[1] with sbp[0] */

	memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);

	return nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
@@ -938,7 +976,7 @@ nilfs_fill_super(struct super_block *sb, void *data, int silent) 


	if (!(sb->s_flags & MS_RDONLY)) {

		down_write(&nilfs->ns_sem);

		nilfs_setup_super(sbi);

		nilfs_setup_super(sbi, true);

		up_write(&nilfs->ns_sem);

	}
@@ -1034,7 +1072,7 @@ static int nilfs_remount(struct super_block *sb, int *flags, char *data) 
			goto restore_opts;



		down_write(&nilfs->ns_sem);

		nilfs_setup_super(sbi);

		nilfs_setup_super(sbi, true);

		up_write(&nilfs->ns_sem);

	}

 out:
@@ -1132,7 +1170,19 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags, 
		goto failed;

	}



	/*

	 * once the super is inserted into the list by sget, s_umount

	 * will protect the lockfs code from trying to start a snapshot

	 * while we are mounting

	 */

	mutex_lock(&sd.bdev->bd_fsfreeze_mutex);

	if (sd.bdev->bd_fsfreeze_count > 0) {

		mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);

		err = -EBUSY;

		goto failed;

	}

	s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, sd.bdev);

	mutex_unlock(&sd.bdev->bd_fsfreeze_mutex);

	if (IS_ERR(s)) {

		err = PTR_ERR(s);

		goto failed;

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