[PATCH U-BOOT 14/26] fs: btrfs: Crossport btrfs_read_sys_array() and btrfs_read_chunk_tree()

Qu Wenruo
2020-04-22T06:49:57Z

These two functions play a big role in btrfs bootstrap.

The following function is removed:
- Seed device support

Although in theory we can still support multiple devices, we don't have
a facility in U-boot to do device scan without opening them.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
fs/btrfs/btrfs.c | 2 +-
fs/btrfs/btrfs.h | 2 +-
fs/btrfs/chunk-map.c | 2 +-
fs/btrfs/volumes.c | 301 +++++++++++++++++++++++++++++++++++++++++++
fs/btrfs/volumes.h | 2 +
5 files changed, 306 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/btrfs.c b/fs/btrfs/btrfs.c
index 1cb56ea0124d..4f2fa2fe6c9f 100644
--- a/fs/btrfs/btrfs.c
+++ b/fs/btrfs/btrfs.c
@@ -98,7 +98,7 @@ int btrfs_probe(struct blk_desc *fs_dev_desc, disk_partition_t *fs_partition)
btrfs_info.chunk_root.objectid = 0;
btrfs_info.chunk_root.bytenr = btrfs_info.sb.chunk_root;

- if (btrfs_read_chunk_tree()) {
+ if (__btrfs_read_chunk_tree()) {
printf("%s: failed to read chunk tree\n", __func__);
return -1;
}
diff --git a/fs/btrfs/btrfs.h b/fs/btrfs/btrfs.h
index 57cdb5aad58c..037492fa06a8 100644
--- a/fs/btrfs/btrfs.h
+++ b/fs/btrfs/btrfs.h
@@ -33,7 +33,7 @@ int btrfs_devread(u64, int, void *);
u64 btrfs_map_logical_to_physical(u64);
int btrfs_chunk_map_init(void);
void btrfs_chunk_map_exit(void);
-int btrfs_read_chunk_tree(void);
+int __btrfs_read_chunk_tree(void);

/* compression.c */
u32 btrfs_decompress(u8 type, const char *, u32, char *, u32);
diff --git a/fs/btrfs/chunk-map.c b/fs/btrfs/chunk-map.c
index 85c3efc63e16..49d8835e14e9 100644
--- a/fs/btrfs/chunk-map.c
+++ b/fs/btrfs/chunk-map.c
@@ -141,7 +141,7 @@ int btrfs_chunk_map_init(void)
return 0;
}

-int btrfs_read_chunk_tree(void)
+int __btrfs_read_chunk_tree(void)
{
struct __btrfs_path path;
struct btrfs_key key, *found_key;
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 63853cb2a1dd..56cf7ac8c631 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -5,6 +5,7 @@
#include "ctree.h"
#include "disk-io.h"
#include "volumes.h"
+#include "extent-io.h"

const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
[BTRFS_RAID_RAID10] = {
@@ -369,6 +370,14 @@ struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
return NULL;
}

+static struct btrfs_device *fill_missing_device(u64 devid)
+{
+ struct btrfs_device *device;
+
+ device = kzalloc(sizeof(*device), GFP_NOFS);
+ return device;
+}
+
/*
* slot == -1: SYSTEM chunk
* return -EIO on error, otherwise return 0
@@ -498,6 +507,298 @@ int btrfs_check_chunk_valid(struct btrfs_fs_info *fs_info,
return 0;
}

+/*
+ * Slot is used to verify the chunk item is valid
+ *
+ * For sys chunk in superblock, pass -1 to indicate sys chunk.
+ */
+static int read_one_chunk(struct btrfs_fs_info *fs_info, struct btrfs_key *key,
+ struct extent_buffer *leaf,
+ struct btrfs_chunk *chunk, int slot)
+{
+ struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
+ struct map_lookup *map;
+ struct cache_extent *ce;
+ u64 logical;
+ u64 length;
+ u64 devid;
+ u8 uuid[BTRFS_UUID_SIZE];
+ int num_stripes;
+ int ret;
+ int i;
+
+ logical = key->offset;
+ length = btrfs_chunk_length(leaf, chunk);
+ num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
+ /* Validation check */
+ ret = btrfs_check_chunk_valid(fs_info, leaf, chunk, slot, logical);
+ if (ret) {
+ error("%s checksums match, but it has an invalid chunk, %s",
+ (slot == -1) ? "Superblock" : "Metadata",
+ (slot == -1) ? "try btrfsck --repair -s <superblock> ie, 0,1,2" : "");
+ return ret;
+ }
+
+ ce = search_cache_extent(&map_tree->cache_tree, logical);
+
+ /* already mapped? */
+ if (ce && ce->start <= logical && ce->start + ce->size > logical) {
+ return 0;
+ }
+
+ map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
+ if (!map)
+ return -ENOMEM;
+
+ map->ce.start = logical;
+ map->ce.size = length;
+ map->num_stripes = num_stripes;
+ map->io_width = btrfs_chunk_io_width(leaf, chunk);
+ map->io_align = btrfs_chunk_io_align(leaf, chunk);
+ map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
+ map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
+ map->type = btrfs_chunk_type(leaf, chunk);
+ map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
+
+ for (i = 0; i < num_stripes; i++) {
+ map->stripes[i].physical =
+ btrfs_stripe_offset_nr(leaf, chunk, i);
+ devid = btrfs_stripe_devid_nr(leaf, chunk, i);
+ read_extent_buffer(leaf, uuid, (unsigned long)
+ btrfs_stripe_dev_uuid_nr(chunk, i),
+ BTRFS_UUID_SIZE);
+ map->stripes[i].dev = btrfs_find_device(fs_info, devid, uuid,
+ NULL);
+ if (!map->stripes[i].dev) {
+ map->stripes[i].dev = fill_missing_device(devid);
+ printf("warning, device %llu is missing\n",
+ (unsigned long long)devid);
+ list_add(&map->stripes[i].dev->dev_list,
+ &fs_info->fs_devices->devices);
+ }
+
+ }
+ ret = insert_cache_extent(&map_tree->cache_tree, &map->ce);
+ if (ret < 0) {
+ errno = -ret;
+ error("failed to add chunk map start=%llu len=%llu: %d (%m)",
+ map->ce.start, map->ce.size, ret);
+ }
+
+ return ret;
+}
+
+static int fill_device_from_item(struct extent_buffer *leaf,
+ struct btrfs_dev_item *dev_item,
+ struct btrfs_device *device)
+{
+ unsigned long ptr;
+
+ device->devid = btrfs_device_id(leaf, dev_item);
+ device->total_bytes = btrfs_device_total_bytes(leaf, dev_item);
+ device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
+ device->type = btrfs_device_type(leaf, dev_item);
+ 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);
+
+ ptr = (unsigned long)btrfs_device_uuid(dev_item);
+ read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
+
+ return 0;
+}
+
+static int read_one_dev(struct btrfs_fs_info *fs_info,
+ struct extent_buffer *leaf,
+ struct btrfs_dev_item *dev_item)
+{
+ struct btrfs_device *device;
+ u64 devid;
+ int ret = 0;
+ u8 fs_uuid[BTRFS_UUID_SIZE];
+ u8 dev_uuid[BTRFS_UUID_SIZE];
+
+ devid = btrfs_device_id(leaf, dev_item);
+ read_extent_buffer(leaf, dev_uuid,
+ (unsigned long)btrfs_device_uuid(dev_item),
+ BTRFS_UUID_SIZE);
+ read_extent_buffer(leaf, fs_uuid,
+ (unsigned long)btrfs_device_fsid(dev_item),
+ BTRFS_FSID_SIZE);
+
+ if (memcmp(fs_uuid, fs_info->fs_devices->fsid, BTRFS_UUID_SIZE)) {
+ error("Seed device is not yet supported\n");
+ return -ENOTSUPP;
+ }
+
+ device = btrfs_find_device(fs_info, devid, dev_uuid, fs_uuid);
+ if (!device) {
+ device = kzalloc(sizeof(*device), GFP_NOFS);
+ if (!device)
+ return -ENOMEM;
+ list_add(&device->dev_list,
+ &fs_info->fs_devices->devices);
+ }
+
+ fill_device_from_item(leaf, dev_item, device);
+ fs_info->fs_devices->total_rw_bytes +=
+ btrfs_device_total_bytes(leaf, dev_item);
+ return ret;
+}
+
+int btrfs_read_sys_array(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_super_block *super_copy = fs_info->super_copy;
+ struct extent_buffer *sb;
+ struct btrfs_disk_key *disk_key;
+ struct btrfs_chunk *chunk;
+ u8 *array_ptr;
+ unsigned long sb_array_offset;
+ int ret = 0;
+ u32 num_stripes;
+ u32 array_size;
+ u32 len = 0;
+ u32 cur_offset;
+ struct btrfs_key key;
+
+ if (fs_info->nodesize < BTRFS_SUPER_INFO_SIZE) {
+ printf("ERROR: nodesize %u too small to read superblock\n",
+ fs_info->nodesize);
+ return -EINVAL;
+ }
+ sb = alloc_dummy_extent_buffer(fs_info, BTRFS_SUPER_INFO_OFFSET,
+ BTRFS_SUPER_INFO_SIZE);
+ if (!sb)
+ return -ENOMEM;
+ btrfs_set_buffer_uptodate(sb);
+ write_extent_buffer(sb, super_copy, 0, sizeof(*super_copy));
+ array_size = btrfs_super_sys_array_size(super_copy);
+
+ array_ptr = super_copy->sys_chunk_array;
+ sb_array_offset = offsetof(struct btrfs_super_block, sys_chunk_array);
+ cur_offset = 0;
+
+ while (cur_offset < array_size) {
+ disk_key = (struct btrfs_disk_key *)array_ptr;
+ len = sizeof(*disk_key);
+ if (cur_offset + len > array_size)
+ goto out_short_read;
+
+ btrfs_disk_key_to_cpu(&key, disk_key);
+
+ array_ptr += len;
+ sb_array_offset += len;
+ cur_offset += len;
+
+ if (key.type == BTRFS_CHUNK_ITEM_KEY) {
+ chunk = (struct btrfs_chunk *)sb_array_offset;
+ /*
+ * At least one btrfs_chunk with one stripe must be
+ * present, exact stripe count check comes afterwards
+ */
+ len = btrfs_chunk_item_size(1);
+ if (cur_offset + len > array_size)
+ goto out_short_read;
+
+ num_stripes = btrfs_chunk_num_stripes(sb, chunk);
+ if (!num_stripes) {
+ printk(
+ "ERROR: invalid number of stripes %u in sys_array at offset %u\n",
+ num_stripes, cur_offset);
+ ret = -EIO;
+ break;
+ }
+
+ len = btrfs_chunk_item_size(num_stripes);
+ if (cur_offset + len > array_size)
+ goto out_short_read;
+
+ ret = read_one_chunk(fs_info, &key, sb, chunk, -1);
+ if (ret)
+ break;
+ } else {
+ printk(
+ "ERROR: unexpected item type %u in sys_array at offset %u\n",
+ (u32)key.type, cur_offset);
+ ret = -EIO;
+ break;
+ }
+ array_ptr += len;
+ sb_array_offset += len;
+ cur_offset += len;
+ }
+ free_extent_buffer(sb);
+ return ret;
+
+out_short_read:
+ printk("ERROR: sys_array too short to read %u bytes at offset %u\n",
+ len, cur_offset);
+ free_extent_buffer(sb);
+ return -EIO;
+}
+
+int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ struct btrfs_root *root = fs_info->chunk_root;
+ int ret;
+ int slot;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ /*
+ * Read all device items, and then all the chunk items. All
+ * device items are found before any chunk item (their object id
+ * is smaller than the lowest possible object id for a chunk
+ * item - BTRFS_FIRST_CHUNK_TREE_OBJECTID).
+ */
+ key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
+ key.offset = 0;
+ key.type = 0;
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto error;
+ while(1) {
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+ if (slot >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret == 0)
+ continue;
+ if (ret < 0)
+ goto error;
+ break;
+ }
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+ if (found_key.type == BTRFS_DEV_ITEM_KEY) {
+ struct btrfs_dev_item *dev_item;
+ dev_item = btrfs_item_ptr(leaf, slot,
+ struct btrfs_dev_item);
+ ret = read_one_dev(fs_info, leaf, dev_item);
+ if (ret < 0)
+ goto error;
+ } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
+ struct btrfs_chunk *chunk;
+ chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
+ ret = read_one_chunk(fs_info, &found_key, leaf, chunk,
+ slot);
+ if (ret < 0)
+ goto error;
+ }
+ path->slots[0]++;
+ }
+
+ ret = 0;
+error:
+ btrfs_free_path(path);
+ return ret;
+}
+
/*
* Get stripe length from chunk item and its stripe items
*
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 4383b4f9c034..d0c09d831c74 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -182,6 +182,8 @@ static inline int btrfs_next_bg_system(struct btrfs_fs_info *fs_info,
return btrfs_next_bg(fs_info, logical, size,
BTRFS_BLOCK_GROUP_SYSTEM);
}
+int btrfs_read_sys_array(struct btrfs_fs_info *fs_info);
+int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info);
int btrfs_open_devices(struct btrfs_fs_devices *fs_devices);
int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
void btrfs_close_all_devices(void);
--
2.26.0