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Commit 74493f7a authored by Chris Mason's avatar Chris Mason
Browse files

Btrfs: Implement generation numbers in block pointers 



Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 17636e03

fs/btrfs/ctree.c

+16 −0
Original line number Diff line number Diff line
@@ -114,6 +114,9 @@ static int __btrfs_cow_block(struct btrfs_trans_handle *trans, 
	} else {

		btrfs_set_node_blockptr(parent, parent_slot,

					cow->start);

		WARN_ON(trans->transid == 0);

		btrfs_set_node_ptr_generation(parent, parent_slot,

					      trans->transid);

		btrfs_mark_buffer_dirty(parent);

		WARN_ON(btrfs_header_generation(parent) != trans->transid);

		btrfs_free_extent(trans, root, buf->start, buf->len, 1);
@@ -967,6 +970,7 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root 
{

	struct extent_buffer *b;

	u64 bytenr;

	u64 ptr_gen;

	int slot;

	int ret;

	int level;
@@ -1031,10 +1035,18 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root 
			if (level == lowest_level)

				break;

			bytenr = btrfs_node_blockptr(b, slot);

			ptr_gen = btrfs_node_ptr_generation(b, slot);

			if (should_reada)

				reada_for_search(root, p, level, slot);

			b = read_tree_block(root, bytenr,

					    btrfs_level_size(root, level - 1));

			if (ptr_gen != btrfs_header_generation(b)) {

				printk("block %llu bad gen wanted %llu "

				       "found %llu\n",

			        (unsigned long long)b->start,

				(unsigned long long)ptr_gen,

			        (unsigned long long)btrfs_header_generation(b));

			}

		} else {

			p->slots[level] = slot;

			if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
@@ -1218,6 +1230,8 @@ static int insert_new_root(struct btrfs_trans_handle *trans, 
		btrfs_node_key(lower, &lower_key, 0);

	btrfs_set_node_key(c, &lower_key, 0);

	btrfs_set_node_blockptr(c, 0, lower->start);

	WARN_ON(btrfs_header_generation(lower) == 0);

	btrfs_set_node_ptr_generation(c, 0, btrfs_header_generation(lower));



	btrfs_mark_buffer_dirty(c);
@@ -1261,6 +1275,8 @@ static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root 
	}

	btrfs_set_node_key(lower, key, slot);

	btrfs_set_node_blockptr(lower, slot, bytenr);

	WARN_ON(trans->transid == 0);

	btrfs_set_node_ptr_generation(lower, slot, trans->transid);

	btrfs_set_header_nritems(lower, nritems + 1);

	btrfs_mark_buffer_dirty(lower);

	return 0;

fs/btrfs/ctree.h

+41 −6
Original line number Diff line number Diff line
@@ -110,7 +110,7 @@ struct btrfs_header { 
#define BTRFS_MAX_LEVEL 8

#define BTRFS_NODEPTRS_PER_BLOCK(r) (((r)->nodesize - \

			        sizeof(struct btrfs_header)) / \

			       (sizeof(struct btrfs_disk_key) + sizeof(u64)))

			        sizeof(struct btrfs_key_ptr))

#define __BTRFS_LEAF_DATA_SIZE(bs) ((bs) - sizeof(struct btrfs_header))

#define BTRFS_LEAF_DATA_SIZE(r) (__BTRFS_LEAF_DATA_SIZE(r->leafsize))

#define BTRFS_MAX_INLINE_DATA_SIZE(r) (BTRFS_LEAF_DATA_SIZE(r) - \
@@ -168,6 +168,7 @@ struct btrfs_leaf { 
struct btrfs_key_ptr {

	struct btrfs_disk_key key;

	__le64 blockptr;

	__le64 generation;

} __attribute__ ((__packed__));



struct btrfs_node {
@@ -196,7 +197,13 @@ struct btrfs_path { 
 */

struct btrfs_extent_item {

	__le32 refs;

	__le64 owner;

} __attribute__ ((__packed__));



struct btrfs_extent_ref {

	__le64 root;

	__le64 generation;

	__le64 objectid;

	__le64 offset;

} __attribute__ ((__packed__));



struct btrfs_inode_timespec {
@@ -402,12 +409,13 @@ struct btrfs_root { 
 * are used, and how many references there are to each block

 */

#define BTRFS_EXTENT_ITEM_KEY	33

#define BTRFS_EXTENT_REF_KEY	34



/*

 * block groups give us hints into the extent allocation trees.  Which

 * blocks are free etc etc

 */

#define BTRFS_BLOCK_GROUP_ITEM_KEY 34

#define BTRFS_BLOCK_GROUP_ITEM_KEY 50



/*

 * string items are for debugging.  They just store a short string of
@@ -529,15 +537,25 @@ BTRFS_SETGET_FUNCS(timespec_nsec, struct btrfs_inode_timespec, nsec, 32); 


/* struct btrfs_extent_item */

BTRFS_SETGET_FUNCS(extent_refs, struct btrfs_extent_item, refs, 32);

BTRFS_SETGET_FUNCS(extent_owner, struct btrfs_extent_item, owner, 64);



/* struct btrfs_extent_ref */

BTRFS_SETGET_FUNCS(ref_root, struct btrfs_extent_ref, root, 64);

BTRFS_SETGET_FUNCS(ref_generation, struct btrfs_extent_ref, generation, 64);

BTRFS_SETGET_FUNCS(ref_objectid, struct btrfs_extent_ref, objectid, 64);

BTRFS_SETGET_FUNCS(ref_offset, struct btrfs_extent_ref, offset, 64);



BTRFS_SETGET_STACK_FUNCS(ref_root, struct btrfs_extent_ref, root, 64);

BTRFS_SETGET_STACK_FUNCS(ref_generation, struct btrfs_extent_ref,

			 generation, 64);

BTRFS_SETGET_STACK_FUNCS(ref_objectid, struct btrfs_extent_ref, objectid, 64);

BTRFS_SETGET_STACK_FUNCS(ref_offset, struct btrfs_extent_ref, offset, 64);



BTRFS_SETGET_STACK_FUNCS(stack_extent_refs, struct btrfs_extent_item,

			 refs, 32);

BTRFS_SETGET_STACK_FUNCS(stack_extent_owner, struct btrfs_extent_item,

			 owner, 64);



/* struct btrfs_node */

BTRFS_SETGET_FUNCS(key_blockptr, struct btrfs_key_ptr, blockptr, 64);

BTRFS_SETGET_FUNCS(key_generation, struct btrfs_key_ptr, generation, 64);



static inline u64 btrfs_node_blockptr(struct extent_buffer *eb, int nr)

{
@@ -556,6 +574,23 @@ static inline void btrfs_set_node_blockptr(struct extent_buffer *eb, 
	btrfs_set_key_blockptr(eb, (struct btrfs_key_ptr *)ptr, val);

}



static inline u64 btrfs_node_ptr_generation(struct extent_buffer *eb, int nr)

{

	unsigned long ptr;

	ptr = offsetof(struct btrfs_node, ptrs) +

		sizeof(struct btrfs_key_ptr) * nr;

	return btrfs_key_generation(eb, (struct btrfs_key_ptr *)ptr);

}



static inline void btrfs_set_node_ptr_generation(struct extent_buffer *eb,

						 int nr, u64 val)

{

	unsigned long ptr;

	ptr = offsetof(struct btrfs_node, ptrs) +

		sizeof(struct btrfs_key_ptr) * nr;

	btrfs_set_key_generation(eb, (struct btrfs_key_ptr *)ptr, val);

}



static inline unsigned long btrfs_node_key_ptr_offset(int nr)

{

	return offsetof(struct btrfs_node, ptrs) +

fs/btrfs/extent-tree.c

+58 −2
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
 */



#include <linux/sched.h>

#include "hash.h"

#include "ctree.h"

#include "disk-io.h"

#include "print-tree.h"
@@ -352,9 +353,63 @@ struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root, 
	return found_group;

}



static u64 hash_extent_ref(u64 root_objectid, u64 root_generation,

			   u64 owner, u64 owner_offset)

{

	u32 high_crc = ~(u32)0;

	u32 low_crc = ~(u32)0;

	__le64 lenum;



	lenum = cpu_to_le64(root_objectid);

	high_crc = crc32c(high_crc, &lenum, sizeof(lenum));

	lenum = cpu_to_le64(root_generation);

	high_crc = crc32c(high_crc, &lenum, sizeof(lenum));



	lenum = cpu_to_le64(owner);

	low_crc = crc32c(low_crc, &lenum, sizeof(lenum));



	lenum = cpu_to_le64(owner_offset);

	low_crc = crc32c(low_crc, &lenum, sizeof(lenum));



	return ((u64)high_crc << 32) | (u64)low_crc;

}



int insert_extent_ref(struct btrfs_trans_handle *trans,

				struct btrfs_root *root,

				struct btrfs_path *path,

				u64 bytenr,

				u64 root_objectid, u64 root_generation,

				u64 owner, u64 owner_offset)

{

	u64 hash;

	struct btrfs_key key;

	struct btrfs_extent_ref ref;

	struct extent_buffer *l;

	struct btrfs_extent_item *item;

	int ret;



	btrfs_set_stack_ref_root(&ref, root_objectid);

	btrfs_set_stack_ref_generation(&ref, root_generation);

	btrfs_set_stack_ref_objectid(&ref, owner);

	btrfs_set_stack_ref_offset(&ref, owner_offset);



	ret = btrfs_name_hash(&ref, sizeof(ref), &hash);

	key.offset = hash;

	key.objectid = bytenr;

	key.type = BTRFS_EXTENT_REF_KEY;



	ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref));

	while (ret == -EEXIST) {



	}



}



int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,

				struct btrfs_root *root,

				u64 bytenr, u64 num_bytes)

				u64 bytenr, u64 num_bytes,

				u64 root_objectid, u64 root_generation,

				u64 owner, u64 owner_offset)

{

	struct btrfs_path *path;

	int ret;
@@ -386,9 +441,10 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, 
	btrfs_mark_buffer_dirty(path->nodes[0]);



	btrfs_release_path(root->fs_info->extent_root, path);

	btrfs_free_path(path);

	finish_current_insert(trans, root->fs_info->extent_root);

	del_pending_extents(trans, root->fs_info->extent_root);



	btrfs_free_path(path);

	return 0;

}