Btrfs: add a device id to device items
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 454eb88..ef3583c 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -91,10 +91,12 @@
__le64 total_blocks;
__le64 blocks_used;
__le64 root_dir_objectid;
+ __le64 last_device_id;
/* fields below here vary with the underlying disk */
__le64 device_block_start;
__le64 device_num_blocks;
__le64 device_root;
+ __le64 device_id;
} __attribute__ ((__packed__));
/*
@@ -230,6 +232,7 @@
struct btrfs_device_item {
__le16 pathlen;
+ __le64 device_id;
} __attribute__ ((__packed__));
struct crypto_hash;
@@ -798,6 +801,28 @@
s->root_dir_objectid = cpu_to_le64(val);
}
+static inline u64 btrfs_super_last_device_id(struct btrfs_super_block *s)
+{
+ return le64_to_cpu(s->last_device_id);
+}
+
+static inline void btrfs_set_super_last_device_id(struct btrfs_super_block *s,
+ u64 val)
+{
+ s->last_device_id = cpu_to_le64(val);
+}
+
+static inline u64 btrfs_super_device_id(struct btrfs_super_block *s)
+{
+ return le64_to_cpu(s->device_id);
+}
+
+static inline void btrfs_set_super_device_id(struct btrfs_super_block *s,
+ u64 val)
+{
+ s->device_id = cpu_to_le64(val);
+}
+
static inline u64 btrfs_super_device_block_start(struct btrfs_super_block *s)
{
return le64_to_cpu(s->device_block_start);
@@ -910,6 +935,17 @@
d->pathlen = cpu_to_le16(val);
}
+static inline u64 btrfs_device_id(struct btrfs_device_item *d)
+{
+ return le64_to_cpu(d->device_id);
+}
+
+static inline void btrfs_set_device_id(struct btrfs_device_item *d,
+ u64 val)
+{
+ d->device_id = cpu_to_le64(val);
+}
+
static inline struct btrfs_root *btrfs_sb(struct super_block *sb)
{
return sb->s_fs_info;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 3ba4df2..06b969c 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -13,11 +13,13 @@
struct dev_lookup {
u64 block_start;
u64 num_blocks;
+ u64 device_id;
struct block_device *bdev;
};
int btrfs_insert_dev_radix(struct btrfs_root *root,
struct block_device *bdev,
+ u64 device_id,
u64 block_start,
u64 num_blocks)
{
@@ -31,6 +33,7 @@
lookup->block_start = block_start;
lookup->num_blocks = num_blocks;
lookup->bdev = bdev;
+ lookup->device_id = device_id;
printk("inserting %s into dev radix %Lu %Lu\n", bdevname(bdev, b), block_start, num_blocks);
ret = radix_tree_insert(&root->fs_info->dev_radix, block_start +
@@ -418,17 +421,14 @@
return root;
}
-int btrfs_open_disk(struct btrfs_root *root, u64 block_start, u64 num_blocks,
- char *filename, int name_len)
+static int btrfs_open_disk(struct btrfs_root *root, u64 device_id,
+ u64 block_start, u64 num_blocks,
+ char *filename, int name_len)
{
char *null_filename;
struct block_device *bdev;
int ret;
- if (block_start == 0) {
-printk("skipping disk with block_start == 0\n");
-return 0;
- }
null_filename = kmalloc(name_len + 1, GFP_NOFS);
if (!null_filename)
return -ENOMEM;
@@ -441,7 +441,8 @@
goto out;
}
set_blocksize(bdev, root->fs_info->sb->s_blocksize);
- ret = btrfs_insert_dev_radix(root, bdev, block_start, num_blocks);
+ ret = btrfs_insert_dev_radix(root, bdev, device_id,
+ block_start, num_blocks);
BUG_ON(ret);
ret = 0;
out:
@@ -490,10 +491,14 @@
}
dev_item = btrfs_item_ptr(leaf, slot, struct btrfs_device_item);
printk("found key %Lu %Lu\n", key.objectid, key.offset);
- ret = btrfs_open_disk(root, key.objectid, key.offset,
- (char *)(dev_item + 1),
- btrfs_device_pathlen(dev_item));
- BUG_ON(ret);
+ if (btrfs_device_id(dev_item) !=
+ btrfs_super_device_id(root->fs_info->disk_super)) {
+ ret = btrfs_open_disk(root, btrfs_device_id(dev_item),
+ key.objectid, key.offset,
+ (char *)(dev_item + 1),
+ btrfs_device_pathlen(dev_item));
+ BUG_ON(ret);
+ }
path->slots[0]++;
}
btrfs_free_path(path);
@@ -556,6 +561,7 @@
dev_lookup->block_start = 0;
dev_lookup->num_blocks = (u32)-2;
dev_lookup->bdev = sb->s_bdev;
+ dev_lookup->device_id = 0;
ret = radix_tree_insert(&fs_info->dev_radix, (u32)-2, dev_lookup);
BUG_ON(ret);
fs_info->sb_buffer = read_tree_block(tree_root,
@@ -575,6 +581,8 @@
radix_tree_delete(&fs_info->dev_radix, (u32)-2);
dev_lookup->block_start = btrfs_super_device_block_start(disk_super);
dev_lookup->num_blocks = btrfs_super_device_num_blocks(disk_super);
+ dev_lookup->device_id = btrfs_super_device_id(disk_super);
+
ret = radix_tree_insert(&fs_info->dev_radix,
dev_lookup->block_start +
dev_lookup->num_blocks - 1, dev_lookup);
@@ -659,6 +667,7 @@
}
return 0;
}
+
static int free_dev_radix(struct btrfs_fs_info *fs_info)
{
struct dev_lookup *lookup[8];
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index aa9f56c..444ebb0 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -44,6 +44,7 @@
u64 bh_blocknr(struct buffer_head *bh);
int btrfs_insert_dev_radix(struct btrfs_root *root,
struct block_device *bdev,
+ u64 device_id,
u64 block_start,
u64 num_blocks);
int btrfs_map_bh_to_logical(struct btrfs_root *root, struct buffer_head *bh,
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index c46d7ea..8dcf600 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1840,7 +1840,9 @@
u16 item_size;
u64 num_blocks;
u64 new_blocks;
+ u64 device_id;
int ret;
+
printk("adding disk %s\n", name);
path = btrfs_alloc_path();
if (!path)
@@ -1875,9 +1877,14 @@
path->slots[0], struct btrfs_device_item);
btrfs_set_device_pathlen(dev_item, namelen);
memcpy(dev_item + 1, name, namelen);
+
+ device_id = btrfs_super_last_device_id(root->fs_info->disk_super) + 1;
+ btrfs_set_super_last_device_id(root->fs_info->disk_super, device_id);
+ btrfs_set_device_id(dev_item, device_id);
mark_buffer_dirty(path->nodes[0]);
- ret = btrfs_insert_dev_radix(root, bdev, num_blocks, new_blocks);
+ ret = btrfs_insert_dev_radix(root, bdev, device_id, num_blocks,
+ new_blocks);
if (!ret) {
btrfs_set_super_total_blocks(root->fs_info->disk_super,