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Commit 5eda7b5e authored by Chris Mason's avatar Chris Mason Committed by David Woodhouse
Browse files

Btrfs: Add the ability to find and remove dead roots after a crash. 



Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 54aa1f4d

fs/btrfs/ctree.h

+15 −2
Original line number Diff line number Diff line
@@ -122,12 +122,12 @@ struct btrfs_super_block { 
	u8 fsid[16];    /* FS specific uuid */

	__le64 blocknr; /* this block number */

	__le64 magic;

	__le32 blocksize;

	__le64 generation;

	__le64 root;

	__le64 total_blocks;

	__le64 blocks_used;

	__le64 root_dir_objectid;

	__le32 blocksize;

} __attribute__ ((__packed__));



/*
@@ -226,10 +226,12 @@ struct btrfs_root_item { 
	struct btrfs_inode_item inode;

	__le64 root_dirid;

	__le64 blocknr;

	__le32 flags;

	__le64 block_limit;

	__le64 blocks_used;

	__le32 flags;

	__le32 refs;

	struct btrfs_disk_key drop_progress;

	u8 drop_level;

} __attribute__ ((__packed__));



#define BTRFS_FILE_EXTENT_REG 0
@@ -800,6 +802,16 @@ static inline void btrfs_set_root_refs(struct btrfs_root_item *item, u32 val) 
	item->refs = cpu_to_le32(val);

}



static inline u32 btrfs_root_flags(struct btrfs_root_item *item)

{

	return le32_to_cpu(item->flags);

}



static inline void btrfs_set_root_flags(struct btrfs_root_item *item, u32 val)

{

	item->flags = cpu_to_le32(val);

}



static inline u64 btrfs_super_blocknr(struct btrfs_super_block *s)

{

	return le64_to_cpu(s->blocknr);
@@ -1076,6 +1088,7 @@ int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root 
		      *item);

int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, struct

			 btrfs_root_item *item, struct btrfs_key *key);

int btrfs_find_dead_roots(struct btrfs_root *root);

/* dir-item.c */

int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root

			  *root, const char *name, int name_len, u64 dir,

fs/btrfs/disk-io.c

+30 −14
Original line number Diff line number Diff line
@@ -326,7 +326,7 @@ static int find_and_setup_root(int blocksize, 
	return 0;

}



struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,

struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_fs_info *fs_info,

					       struct btrfs_key *location)

{

	struct btrfs_root *root;
@@ -336,11 +336,7 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info, 
	u64 highest_inode;

	int ret = 0;



	root = radix_tree_lookup(&fs_info->fs_roots_radix,

				 (unsigned long)location->objectid);

	if (root)

		return root;

	root = kmalloc(sizeof(*root), GFP_NOFS);

	root = kzalloc(sizeof(*root), GFP_NOFS);

	if (!root)

		return ERR_PTR(-ENOMEM);

	if (location->offset == (u64)-1) {
@@ -383,6 +379,28 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info, 
	BUG_ON(!root->node);

insert:

	root->ref_cows = 1;

	ret = btrfs_find_highest_inode(root, &highest_inode);

	if (ret == 0) {

		root->highest_inode = highest_inode;

		root->last_inode_alloc = highest_inode;

	}

	return root;

}



struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,

				      struct btrfs_key *location)

{

	struct btrfs_root *root;

	int ret;



	root = radix_tree_lookup(&fs_info->fs_roots_radix,

				 (unsigned long)location->objectid);

	if (root)

		return root;



	root = btrfs_read_fs_root_no_radix(fs_info, location);

	if (IS_ERR(root))

		return root;

	ret = radix_tree_insert(&fs_info->fs_roots_radix,

				(unsigned long)root->root_key.objectid,

				root);
@@ -391,11 +409,6 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info, 
		kfree(root);

		return ERR_PTR(ret);

	}

	ret = btrfs_find_highest_inode(root, &highest_inode);

	if (ret == 0) {

		root->highest_inode = highest_inode;

		root->last_inode_alloc = highest_inode;

	}

	return root;

}
@@ -489,6 +502,9 @@ struct btrfs_root *open_ctree(struct super_block *sb) 
	btrfs_read_block_groups(extent_root);



	fs_info->generation = btrfs_super_generation(disk_super) + 1;

	ret = btrfs_find_dead_roots(tree_root);

	if (ret)

		goto fail_tree_root;

	mutex_unlock(&fs_info->fs_mutex);

	return tree_root;
@@ -538,7 +554,7 @@ int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root 
	return 0;

}



static int free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)

int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)

{

	radix_tree_delete(&fs_info->fs_roots_radix,

			  (unsigned long)root->root_key.objectid);
@@ -565,7 +581,7 @@ static int del_fs_roots(struct btrfs_fs_info *fs_info) 
		if (!ret)

			break;

		for (i = 0; i < ret; i++)

			free_fs_root(fs_info, gang[i]);

			btrfs_free_fs_root(fs_info, gang[i]);

	}

	return 0;

}

fs/btrfs/disk-io.h

+3 −0
Original line number Diff line number Diff line
@@ -65,6 +65,8 @@ int btrfs_csum_data(struct btrfs_root * root, char *data, size_t len, 
		    char *result);

struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,

				      struct btrfs_key *location);

struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_fs_info *fs_info,

					       struct btrfs_key *location);

u64 bh_blocknr(struct buffer_head *bh);

int btrfs_insert_dev_radix(struct btrfs_root *root,

			   struct block_device *bdev,
@@ -75,4 +77,5 @@ int btrfs_map_bh_to_logical(struct btrfs_root *root, struct buffer_head *bh, 
			     u64 logical);

int btrfs_releasepage(struct page *page, gfp_t flags);

void btrfs_btree_balance_dirty(struct btrfs_root *root);

int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root);

#endif

fs/btrfs/inode.c

+2 −0
Original line number Diff line number Diff line
@@ -2028,6 +2028,8 @@ static int create_subvol(struct btrfs_root *root, char *name, int namelen) 


	btrfs_set_root_blocknr(&root_item, bh_blocknr(subvol));

	btrfs_set_root_refs(&root_item, 1);

	memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));

	root_item.drop_level = 0;

	brelse(subvol);

	subvol = NULL;

fs/btrfs/root-tree.c

+66 −9
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 


#include <linux/module.h>

#include "ctree.h"

#include "transaction.h"

#include "disk-io.h"

#include "print-tree.h"
@@ -32,7 +33,7 @@ int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, 


	search_key.objectid = objectid;

	search_key.flags = (u32)-1;

	search_key.offset = (u32)-1;

	search_key.offset = (u64)-1;



	path = btrfs_alloc_path();

	BUG_ON(!path);
@@ -50,6 +51,7 @@ int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, 
	memcpy(item, btrfs_item_ptr(l, slot, struct btrfs_root_item),

		sizeof(*item));

	btrfs_disk_key_to_cpu(key, &l->items[slot].key);

printk("find last finds key %Lu %u %Lu slot %d search for obj %Lu\n", key->objectid, key->flags, key->offset, slot, objectid);

	ret = 0;

out:

	btrfs_release_path(root, path);
@@ -93,6 +95,67 @@ int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root 
	return ret;

}



int btrfs_find_dead_roots(struct btrfs_root *root)

{

	struct btrfs_root *dead_root;

	struct btrfs_item *item;

	struct btrfs_root_item *ri;

	struct btrfs_key key;

	struct btrfs_path *path;

	int ret;

	u32 nritems;

	struct btrfs_leaf *leaf;

	int slot;



	key.objectid = 0;

	key.flags = 0;

	btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);

	key.offset = 0;

	path = btrfs_alloc_path();

	if (!path)

		return -ENOMEM;

	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);

	if (ret < 0)

		goto err;

	while(1) {

		leaf = btrfs_buffer_leaf(path->nodes[0]);

		nritems = btrfs_header_nritems(&leaf->header);

		slot = path->slots[0];

		if (slot >= nritems) {

			ret = btrfs_next_leaf(root, path);

			if (ret)

				break;

			leaf = btrfs_buffer_leaf(path->nodes[0]);

			nritems = btrfs_header_nritems(&leaf->header);

			slot = path->slots[0];

		}

		item = leaf->items + slot;

		btrfs_disk_key_to_cpu(&key, &item->key);

		if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY)

			goto next;

		ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item);

		if (btrfs_root_refs(ri) != 0)

			goto next;

		dead_root = btrfs_read_fs_root_no_radix(root->fs_info, &key);

		if (IS_ERR(root)) {

			ret = PTR_ERR(root);

			goto err;

		}

printk("found dead root %Lu %u %Lu\n", key.objectid, key.flags, key.offset);

		ret = btrfs_add_dead_root(dead_root,

					  &root->fs_info->dead_roots);

		if (ret)

			goto err;

next:

		slot++;

		path->slots[0]++;

	}

	ret = 0;

err:

	btrfs_free_path(path);

	return ret;

}



int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,

		   struct btrfs_key *key)

{
@@ -111,14 +174,8 @@ int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, 
			    path->slots[0], struct btrfs_root_item);



	refs = btrfs_root_refs(ri);

	BUG_ON(refs == 0);

	if (refs == 1) {

	BUG_ON(refs != 0);

	ret = btrfs_del_item(trans, root, path);

	} else {

		btrfs_set_root_refs(ri, refs - 1);

		WARN_ON(1);

		mark_buffer_dirty(path->nodes[0]);

	}

out:

	btrfs_release_path(root, path);

	btrfs_free_path(path);