Btrfs: Move device information into the super block so it can be scanned

Signed-off-by: Chris Mason <chris.mason@oracle.com>

5 files changed, 23 insertions, 91 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 285fb7e46106..96a493217860 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -150,21 +150,11 @@ struct btrfs_dev_item {
         /* minimal io size for this device */
         __le32 sector_size;
 
-        /* the kernel device number */
-        __le64 rdev;
-
         /* type and info about this device */
         __le64 type;
 
-        /* partition number, 0 for whole dev */
-        __le32 partition;
-
-        /* length of the name data at the end of the item */
-        __le16 name_len;
-
-        /* physical drive uuid (or lvm uuid) */
+        /* btrfs generated uuid for this device */
         u8 uuid[BTRFS_DEV_UUID_SIZE];
-        /* name goes here */
 } __attribute__ ((__packed__));
 
 struct btrfs_stripe {
@@ -255,6 +245,7 @@ struct btrfs_super_block {
         __le32 sys_chunk_array_size;
         u8 root_level;
         u8 chunk_root_level;
+        struct btrfs_dev_item dev_item;
         u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
 } __attribute__ ((__packed__));
 
@@ -685,20 +676,12 @@ BTRFS_SETGET_FUNCS(device_io_align, struct btrfs_dev_item, io_align, 32);
 BTRFS_SETGET_FUNCS(device_io_width, struct btrfs_dev_item, io_width, 32);
 BTRFS_SETGET_FUNCS(device_sector_size, struct btrfs_dev_item, sector_size, 32);
 BTRFS_SETGET_FUNCS(device_id, struct btrfs_dev_item, devid, 64);
-BTRFS_SETGET_FUNCS(device_rdev, struct btrfs_dev_item, rdev, 64);
-BTRFS_SETGET_FUNCS(device_partition, struct btrfs_dev_item, partition, 32);
-BTRFS_SETGET_FUNCS(device_name_len, struct btrfs_dev_item, name_len, 16);
 
 static inline char *btrfs_device_uuid(struct btrfs_dev_item *d)
 {
         return (char *)d + offsetof(struct btrfs_dev_item, uuid);
 }
 
-static inline char *btrfs_device_name(struct btrfs_dev_item *d)
-{
-        return (char *)(d + 1);
-}
-
 BTRFS_SETGET_FUNCS(chunk_owner, struct btrfs_chunk, owner, 64);
 BTRFS_SETGET_FUNCS(chunk_stripe_len, struct btrfs_chunk, stripe_len, 64);
 BTRFS_SETGET_FUNCS(chunk_io_align, struct btrfs_chunk, io_align, 32);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 2a239ae49f78..26185d46712c 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -370,7 +370,6 @@ static int close_all_devices(struct btrfs_fs_info *fs_info)
                 next = list->next;
                 list_del(next);
                 device = list_entry(next, struct btrfs_device, dev_list);
-                kfree(device->name);
                 kfree(device);
         }
         return 0;
@@ -800,6 +799,9 @@ struct btrfs_root *open_ctree(struct super_block *sb)
         }
 
         mutex_lock(&fs_info->fs_mutex);
+        ret = btrfs_read_super_device(tree_root, fs_info->sb_buffer);
+        BUG_ON(ret);
+
         ret = btrfs_read_sys_array(tree_root);
         BUG_ON(ret);
 
diff --git a/fs/btrfs/print-tree.c b/fs/btrfs/print-tree.c
index 9c1335dad40c..ee0de112cf5a 100644
--- a/fs/btrfs/print-tree.c
+++ b/fs/btrfs/print-tree.c
@@ -37,22 +37,11 @@ static void print_chunk(struct extent_buffer *eb, struct btrfs_chunk *chunk)
 static void print_dev_item(struct extent_buffer *eb,
                            struct btrfs_dev_item *dev_item)
 {
-        char *name;
-        int name_len;
-
-        name_len = btrfs_device_name_len(eb, dev_item);
-        name = kmalloc(name_len, GFP_NOFS);
-        if (name) {
-                read_extent_buffer(eb, name,
-                                   (unsigned long)btrfs_device_name(dev_item),
-                                   name_len);
-        }
-        printk("\t\tdev item name %.*s devid %llu "
-               "total_bytes %llu bytes used %Lu\n", name_len, name,
+        printk("\t\tdev item devid %llu "
+               "total_bytes %llu bytes used %Lu\n",
                (unsigned long long)btrfs_device_id(eb, dev_item),
                (unsigned long long)btrfs_device_total_bytes(eb, dev_item),
                (unsigned long long)btrfs_device_bytes_used(eb, dev_item));
-        kfree(name);
 }
 void btrfs_print_leaf(struct btrfs_root *root, struct extent_buffer *l)
 {
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index a52a13f365d6..ae22d01ecf54 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -278,7 +278,7 @@ int btrfs_add_device(struct btrfs_trans_handle *trans,
         key.offset = free_devid;
 
         ret = btrfs_insert_empty_item(trans, root, path, &key,
-                                      sizeof(*dev_item) + device->name_len);
+                                      sizeof(*dev_item));
         if (ret)
                 goto out;
 
@@ -290,15 +290,9 @@ int btrfs_add_device(struct btrfs_trans_handle *trans,
         btrfs_set_device_io_align(leaf, dev_item, device->io_align);
         btrfs_set_device_io_width(leaf, dev_item, device->io_width);
         btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
-        btrfs_set_device_rdev(leaf, dev_item, device->rdev);
-        btrfs_set_device_partition(leaf, dev_item, device->partition);
-        btrfs_set_device_name_len(leaf, dev_item, device->name_len);
         btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
         btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
 
-        ptr = (unsigned long)btrfs_device_name(dev_item);
-        write_extent_buffer(leaf, device->name, ptr, device->name_len);
-
         ptr = (unsigned long)btrfs_device_uuid(dev_item);
         write_extent_buffer(leaf, device->uuid, ptr, BTRFS_DEV_UUID_SIZE);
         btrfs_mark_buffer_dirty(leaf);
@@ -345,8 +339,6 @@ int btrfs_update_device(struct btrfs_trans_handle *trans,
         btrfs_set_device_io_align(leaf, dev_item, device->io_align);
         btrfs_set_device_io_width(leaf, dev_item, device->io_width);
         btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
-        btrfs_set_device_rdev(leaf, dev_item, device->rdev);
-        btrfs_set_device_partition(leaf, dev_item, device->partition);
         btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
         btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
         btrfs_mark_buffer_dirty(leaf);
@@ -676,7 +668,6 @@ static int fill_device_from_item(struct extent_buffer *leaf,
                                  struct btrfs_device *device)
 {
         unsigned long ptr;
-        char *name;
 
         device->devid = btrfs_device_id(leaf, dev_item);
         device->total_bytes = btrfs_device_total_bytes(leaf, dev_item);
@@ -685,24 +676,14 @@ static int fill_device_from_item(struct extent_buffer *leaf,
         device->io_align = btrfs_device_io_align(leaf, dev_item);
         device->io_width = btrfs_device_io_width(leaf, dev_item);
         device->sector_size = btrfs_device_sector_size(leaf, dev_item);
-        device->rdev = btrfs_device_rdev(leaf, dev_item);
-        device->partition = btrfs_device_partition(leaf, dev_item);
-        device->name_len = btrfs_device_name_len(leaf, dev_item);
 
         ptr = (unsigned long)btrfs_device_uuid(dev_item);
         read_extent_buffer(leaf, device->uuid, ptr, BTRFS_DEV_UUID_SIZE);
 
-        name = kmalloc(device->name_len + 1, GFP_NOFS);
-        if (!name)
-                return -ENOMEM;
-        device->name = name;
-        ptr = (unsigned long)btrfs_device_name(dev_item);
-        read_extent_buffer(leaf, name, ptr, device->name_len);
-        name[device->name_len] = '\0';
         return 0;
 }
 
-static int read_one_dev(struct btrfs_root *root, struct btrfs_key *key,
+static int read_one_dev(struct btrfs_root *root,
                         struct extent_buffer *leaf,
                         struct btrfs_dev_item *dev_item)
 {
@@ -722,7 +703,6 @@ static int read_one_dev(struct btrfs_root *root, struct btrfs_key *key,
         fill_device_from_item(leaf, dev_item, device);
         device->dev_root = root->fs_info->dev_root;
         device->bdev = root->fs_info->sb->s_bdev;
-        memcpy(&device->dev_key, key, sizeof(*key));
         ret = 0;
 #if 0
         ret = btrfs_open_device(device);
@@ -733,12 +713,20 @@ static int read_one_dev(struct btrfs_root *root, struct btrfs_key *key,
         return ret;
 }
 
+int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf)
+{
+        struct btrfs_dev_item *dev_item;
+
+        dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block,
+                                                     dev_item);
+        return read_one_dev(root, buf, dev_item);
+}
+
 int btrfs_read_sys_array(struct btrfs_root *root)
 {
         struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
         struct extent_buffer *sb = root->fs_info->sb_buffer;
         struct btrfs_disk_key *disk_key;
-        struct btrfs_dev_item *dev_item;
         struct btrfs_chunk *chunk;
         struct btrfs_key key;
         u32 num_stripes;
@@ -748,7 +736,6 @@ int btrfs_read_sys_array(struct btrfs_root *root)
         unsigned long sb_ptr;
         u32 cur;
         int ret;
-        int dev_only = 1;
 
         array_size = btrfs_super_sys_array_size(super_copy);
 
@@ -757,7 +744,6 @@ int btrfs_read_sys_array(struct btrfs_root *root)
          * once for all of the chunks.  This way there are device
          * structs filled in for every chunk
          */
-again:
         ptr = super_copy->sys_chunk_array;
         sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
         cur = 0;
@@ -771,22 +757,10 @@ again:
                 sb_ptr += len;
                 cur += len;
 
-                if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID &&
-                    key.type == BTRFS_DEV_ITEM_KEY) {
-                        dev_item = (struct btrfs_dev_item *)sb_ptr;
-                        if (dev_only) {
-                                ret = read_one_dev(root, &key, sb, dev_item);
-                                BUG_ON(ret);
-                        }
-                        len = sizeof(*dev_item);
-                        len += btrfs_device_name_len(sb, dev_item);
-                } else if (key.type == BTRFS_CHUNK_ITEM_KEY) {
-
+                if (key.type == BTRFS_CHUNK_ITEM_KEY) {
                         chunk = (struct btrfs_chunk *)sb_ptr;
-                        if (!dev_only) {
-                                ret = read_one_chunk(root, &key, sb, chunk);
-                                BUG_ON(ret);
-                        }
+                        ret = read_one_chunk(root, &key, sb, chunk);
+                        BUG_ON(ret);
                         num_stripes = btrfs_chunk_num_stripes(sb, chunk);
                         len = btrfs_chunk_item_size(num_stripes);
                 } else {
@@ -796,10 +770,6 @@ again:
                 sb_ptr += len;
                 cur += len;
         }
-        if (dev_only == 1) {
-                dev_only = 0;
-                goto again;
-        }
         return 0;
 }
 
@@ -846,8 +816,7 @@ again:
                                 struct btrfs_dev_item *dev_item;
                                 dev_item = btrfs_item_ptr(leaf, slot,
                                                   struct btrfs_dev_item);
-                                ret = read_one_dev(root, &found_key, leaf,
-                                                   dev_item);
+                                ret = read_one_dev(root, leaf, dev_item);
                                 BUG_ON(ret);
                         }
                 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 4ab9891878a8..77fa6efd79cf 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -21,7 +21,6 @@
 struct btrfs_device {
         struct list_head dev_list;
         struct btrfs_root *dev_root;
-        struct btrfs_key dev_key;
 
         struct block_device *bdev;
 
@@ -43,22 +42,11 @@ struct btrfs_device {
         /* minimal io size for this device */
         u32 sector_size;
 
-        /* the kernel device number */
-        u64 rdev;
-
         /* type and info about this device */
         u64 type;
 
-        /* partition number, 0 for whole dev */
-        int partition;
-
-        /* length of the name data at the end of the item */
-        int name_len;
-
         /* physical drive uuid (or lvm uuid) */
         u8 uuid[BTRFS_DEV_UUID_SIZE];
-
-        char *name;
 };
 
 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
@@ -75,4 +63,5 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 void btrfs_mapping_init(struct btrfs_mapping_tree *tree);
 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree);
 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio);
+int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf);
 #endif