[PATCH U-BOOT 06/26] fs: btrfs: Cross-port extent-io.[ch] from btrfs-progs

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

This cross port brings the extent_io_tree infrastructure, with that we
could finally bring in proper btrfs_fs_info structure to ctree.h.

Also with read/write_extent_buffer() implemented, also backport
read/write_eb_member() to ctree.h.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
fs/btrfs/Makefile | 2 +-
fs/btrfs/ctree.h | 55 +++
fs/btrfs/extent-io.c | 801 ++++++++++++++++++++++++++++++++++++++++++-
fs/btrfs/extent-io.h | 164 +++++++++
4 files changed, 1020 insertions(+), 2 deletions(-)
create mode 100644 fs/btrfs/extent-io.h

diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index 53be6e8835f2..6dac3a7e239b 100644
--- a/fs/btrfs/Makefile
+++ b/fs/btrfs/Makefile
@@ -4,4 +4,4 @@

obj-y := btrfs.o chunk-map.o compression.o ctree.o dev.o dir-item.o \
extent-io.o inode.o root.o subvolume.o crypto/hash.o disk-io.o \
- common/rbtree-utils.o extent-cache.o
+ common/rbtree-utils.o extent-cache.o extent-io.o
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 02125e5e100c..c7528d1ac3db 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -11,8 +11,10 @@

#include <common.h>
#include <compiler.h>
+#include <linux/rbtree.h>
#include "kernel-shared/btrfs_tree.h"
#include "compat.h"
+#include "extent-io.h"

#define BTRFS_MAX_MIRRORS 3

@@ -48,6 +50,18 @@
#define BTRFS_FS_STATE_DEV_REPLACING 3
#define BTRFS_FS_STATE_DUMMY_FS_INFO 4

+#define read_eb_member(eb, ptr, type, member, result) ( \
+ read_extent_buffer(eb, (char *)(result), \
+ ((unsigned long)(ptr)) + \
+ offsetof(type, member), \
+ sizeof(((type *)0)->member)))
+
+#define write_eb_member(eb, ptr, type, member, result) ( \
+ write_extent_buffer(eb, (char *)(result), \
+ ((unsigned long)(ptr)) + \
+ offsetof(type, member), \
+ sizeof(((type *)0)->member)))
+
#define BTRFS_SETGET_STACK_FUNCS(name, type, member, bits) \
static inline u##bits btrfs_##name(const type *s) \
{ \
@@ -75,6 +89,47 @@ struct btrfs_root {
u64 root_dirid;
};

+struct btrfs_mapping_tree {
+ struct cache_tree cache_tree;
+};
+
+struct btrfs_device;
+struct btrfs_fs_info {
+ u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
+ u8 *new_chunk_tree_uuid;
+ struct btrfs_root *fs_root;
+ struct btrfs_root *tree_root;
+ struct btrfs_root *chunk_root;
+ struct btrfs_root *csum_root;
+
+ struct rb_root fs_root_tree;
+
+ struct extent_io_tree extent_cache;
+ struct extent_io_tree free_space_cache;
+ struct extent_io_tree pinned_extents;
+ struct extent_io_tree extent_ins;
+ struct extent_io_tree *excluded_extents;
+
+ struct rb_root block_group_cache_tree;
+ /* logical->physical extent mapping */
+ struct btrfs_mapping_tree mapping_tree;
+
+ u64 generation;
+ u64 last_trans_committed;
+
+ struct btrfs_super_block *super_copy;
+
+ u64 super_bytenr;
+
+ /* Only support one device yet */
+ struct btrfs_devvice *dev;
+
+ /* Cached block sizes */
+ u32 nodesize;
+ u32 sectorsize;
+ u32 stripesize;
+};
+
int btrfs_comp_keys(struct btrfs_key *, struct btrfs_key *);
int btrfs_comp_keys_type(struct btrfs_key *, struct btrfs_key *);
int btrfs_bin_search(union btrfs_tree_node *, struct btrfs_key *, int *);
diff --git a/fs/btrfs/extent-io.c b/fs/btrfs/extent-io.c
index 66d0e1c7d65f..dc0832c8645f 100644
--- a/fs/btrfs/extent-io.c
+++ b/fs/btrfs/extent-io.c
@@ -5,9 +5,13 @@
* 2017 Marek Behun, CZ.NIC, marek.behun at nic.cz
*/

-#include "btrfs.h"
+#include <linux/kernel.h>
#include <malloc.h>
#include <memalign.h>
+#include "btrfs.h"
+#include "ctree.h"
+#include "extent-io.h"
+#include "disk-io.h"

u64 btrfs_read_extent_inline(struct btrfs_path *path,
struct btrfs_file_extent_item *extent, u64 offset,
@@ -118,3 +122,798 @@ err:
free(cbuf);
return -1ULL;
}
+
+void extent_io_tree_init(struct extent_io_tree *tree)
+{
+ cache_tree_init(&tree->state);
+ cache_tree_init(&tree->cache);
+ tree->cache_size = 0;
+}
+
+static struct extent_state *alloc_extent_state(void)
+{
+ struct extent_state *state;
+
+ state = malloc(sizeof(*state));
+ if (!state)
+ return NULL;
+ state->cache_node.objectid = 0;
+ state->refs = 1;
+ state->state = 0;
+ state->xprivate = 0;
+ return state;
+}
+
+static void btrfs_free_extent_state(struct extent_state *state)
+{
+ state->refs--;
+ BUG_ON(state->refs < 0);
+ if (state->refs == 0)
+ free(state);
+}
+
+static void free_extent_state_func(struct cache_extent *cache)
+{
+ struct extent_state *es;
+
+ es = container_of(cache, struct extent_state, cache_node);
+ btrfs_free_extent_state(es);
+}
+
+static void free_extent_buffer_final(struct extent_buffer *eb);
+void extent_io_tree_cleanup(struct extent_io_tree *tree)
+{
+ cache_tree_free_extents(&tree->state, free_extent_state_func);
+}
+
+static inline void update_extent_state(struct extent_state *state)
+{
+ state->cache_node.start = state->start;
+ state->cache_node.size = state->end + 1 - state->start;
+}
+
+/*
+ * Utility function to look for merge candidates inside a given range.
+ * Any extents with matching state are merged together into a single
+ * extent in the tree. Extents with EXTENT_IO in their state field are
+ * not merged
+ */
+static int merge_state(struct extent_io_tree *tree,
+ struct extent_state *state)
+{
+ struct extent_state *other;
+ struct cache_extent *other_node;
+
+ if (state->state & EXTENT_IOBITS)
+ return 0;
+
+ other_node = prev_cache_extent(&state->cache_node);
+ if (other_node) {
+ other = container_of(other_node, struct extent_state,
+ cache_node);
+ if (other->end == state->start - 1 &&
+ other->state == state->state) {
+ state->start = other->start;
+ update_extent_state(state);
+ remove_cache_extent(&tree->state, &other->cache_node);
+ btrfs_free_extent_state(other);
+ }
+ }
+ other_node = next_cache_extent(&state->cache_node);
+ if (other_node) {
+ other = container_of(other_node, struct extent_state,
+ cache_node);
+ if (other->start == state->end + 1 &&
+ other->state == state->state) {
+ other->start = state->start;
+ update_extent_state(other);
+ remove_cache_extent(&tree->state, &state->cache_node);
+ btrfs_free_extent_state(state);
+ }
+ }
+ return 0;
+}
+
+/*
+ * insert an extent_state struct into the tree. 'bits' are set on the
+ * struct before it is inserted.
+ */
+static int insert_state(struct extent_io_tree *tree,
+ struct extent_state *state, u64 start, u64 end,
+ int bits)
+{
+ int ret;
+
+ BUG_ON(end < start);
+ state->state |= bits;
+ state->start = start;
+ state->end = end;
+ update_extent_state(state);
+ ret = insert_cache_extent(&tree->state, &state->cache_node);
+ BUG_ON(ret);
+ merge_state(tree, state);
+ return 0;
+}
+
+/*
+ * split a given extent state struct in two, inserting the preallocated
+ * struct 'prealloc' as the newly created second half. 'split' indicates an
+ * offset inside 'orig' where it should be split.
+ */
+static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
+ struct extent_state *prealloc, u64 split)
+{
+ int ret;
+ prealloc->start = orig->start;
+ prealloc->end = split - 1;
+ prealloc->state = orig->state;
+ update_extent_state(prealloc);
+ orig->start = split;
+ update_extent_state(orig);
+ ret = insert_cache_extent(&tree->state, &prealloc->cache_node);
+ BUG_ON(ret);
+ return 0;
+}
+
+/*
+ * clear some bits on a range in the tree.
+ */
+static int clear_state_bit(struct extent_io_tree *tree,
+ struct extent_state *state, int bits)
+{
+ int ret = state->state & bits;
+
+ state->state &= ~bits;
+ if (state->state == 0) {
+ remove_cache_extent(&tree->state, &state->cache_node);
+ btrfs_free_extent_state(state);
+ } else {
+ merge_state(tree, state);
+ }
+ return ret;
+}
+
+/*
+ * extent_buffer_bitmap_set - set an area of a bitmap
+ * @eb: the extent buffer
+ * @start: offset of the bitmap item in the extent buffer
+ * @pos: bit number of the first bit
+ * @len: number of bits to set
+ */
+void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
+ unsigned long pos, unsigned long len)
+{
+ u8 *p = (u8 *)eb->data + start + BIT_BYTE(pos);
+ const unsigned int size = pos + len;
+ int bits_to_set = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
+ u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(pos);
+
+ while (len >= bits_to_set) {
+ *p |= mask_to_set;
+ len -= bits_to_set;
+ bits_to_set = BITS_PER_BYTE;
+ mask_to_set = ~0;
+ p++;
+ }
+ if (len) {
+ mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
+ *p |= mask_to_set;
+ }
+}
+
+/*
+ * extent_buffer_bitmap_clear - clear an area of a bitmap
+ * @eb: the extent buffer
+ * @start: offset of the bitmap item in the extent buffer
+ * @pos: bit number of the first bit
+ * @len: number of bits to clear
+ */
+void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
+ unsigned long pos, unsigned long len)
+{
+ u8 *p = (u8 *)eb->data + start + BIT_BYTE(pos);
+ const unsigned int size = pos + len;
+ int bits_to_clear = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
+ u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos);
+
+ while (len >= bits_to_clear) {
+ *p &= ~mask_to_clear;
+ len -= bits_to_clear;
+ bits_to_clear = BITS_PER_BYTE;
+ mask_to_clear = ~0;
+ p++;
+ }
+ if (len) {
+ mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
+ *p &= ~mask_to_clear;
+ }
+}
+
+/*
+ * clear some bits on a range in the tree.
+ */
+int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, int bits)
+{
+ struct extent_state *state;
+ struct extent_state *prealloc = NULL;
+ struct cache_extent *node;
+ u64 last_end;
+ int err;
+ int set = 0;
+
+again:
+ if (!prealloc) {
+ prealloc = alloc_extent_state();
+ if (!prealloc)
+ return -ENOMEM;
+ }
+
+ /*
+ * this search will find the extents that end after
+ * our range starts
+ */
+ node = search_cache_extent(&tree->state, start);
+ if (!node)
+ goto out;
+ state = container_of(node, struct extent_state, cache_node);
+ if (state->start > end)
+ goto out;
+ last_end = state->end;
+
+ /*
+ * | ---- desired range ---- |
+ * | state | or
+ * | ------------- state -------------- |
+ *
+ * We need to split the extent we found, and may flip
+ * bits on second half.
+ *
+ * If the extent we found extends past our range, we
+ * just split and search again. It'll get split again
+ * the next time though.
+ *
+ * If the extent we found is inside our range, we clear
+ * the desired bit on it.
+ */
+ if (state->start < start) {
+ err = split_state(tree, state, prealloc, start);
+ BUG_ON(err == -EEXIST);
+ prealloc = NULL;
+ if (err)
+ goto out;
+ if (state->end <= end) {
+ set |= clear_state_bit(tree, state, bits);
+ if (last_end == (u64)-1)
+ goto out;
+ start = last_end + 1;
+ } else {
+ start = state->start;
+ }
+ goto search_again;
+ }
+ /*
+ * | ---- desired range ---- |
+ * | state |
+ * We need to split the extent, and clear the bit
+ * on the first half
+ */
+ if (state->start <= end && state->end > end) {
+ err = split_state(tree, state, prealloc, end + 1);
+ BUG_ON(err == -EEXIST);
+
+ set |= clear_state_bit(tree, prealloc, bits);
+ prealloc = NULL;
+ goto out;
+ }
+
+ start = state->end + 1;
+ set |= clear_state_bit(tree, state, bits);
+ if (last_end == (u64)-1)
+ goto out;
+ start = last_end + 1;
+ goto search_again;
+out:
+ if (prealloc)
+ btrfs_free_extent_state(prealloc);
+ return set;
+
+search_again:
+ if (start > end)
+ goto out;
+ goto again;
+}
+
+/*
+ * set some bits on a range in the tree.
+ */
+int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, int bits)
+{
+ struct extent_state *state;
+ struct extent_state *prealloc = NULL;
+ struct cache_extent *node;
+ int err = 0;
+ u64 last_start;
+ u64 last_end;
+again:
+ if (!prealloc) {
+ prealloc = alloc_extent_state();
+ if (!prealloc)
+ return -ENOMEM;
+ }
+
+ /*
+ * this search will find the extents that end after
+ * our range starts
+ */
+ node = search_cache_extent(&tree->state, start);
+ if (!node) {
+ err = insert_state(tree, prealloc, start, end, bits);
+ BUG_ON(err == -EEXIST);
+ prealloc = NULL;
+ goto out;
+ }
+
+ state = container_of(node, struct extent_state, cache_node);
+ last_start = state->start;
+ last_end = state->end;
+
+ /*
+ * | ---- desired range ---- |
+ * | state |
+ *
+ * Just lock what we found and keep going
+ */
+ if (state->start == start && state->end <= end) {
+ state->state |= bits;
+ merge_state(tree, state);
+ if (last_end == (u64)-1)
+ goto out;
+ start = last_end + 1;
+ goto search_again;
+ }
+ /*
+ * | ---- desired range ---- |
+ * | state |
+ * or
+ * | ------------- state -------------- |
+ *
+ * We need to split the extent we found, and may flip bits on
+ * second half.
+ *
+ * If the extent we found extends past our
+ * range, we just split and search again. It'll get split
+ * again the next time though.
+ *
+ * If the extent we found is inside our range, we set the
+ * desired bit on it.
+ */
+ if (state->start < start) {
+ err = split_state(tree, state, prealloc, start);
+ BUG_ON(err == -EEXIST);
+ prealloc = NULL;
+ if (err)
+ goto out;
+ if (state->end <= end) {
+ state->state |= bits;
+ start = state->end + 1;
+ merge_state(tree, state);
+ if (last_end == (u64)-1)
+ goto out;
+ start = last_end + 1;
+ } else {
+ start = state->start;
+ }
+ goto search_again;
+ }
+ /*
+ * | ---- desired range ---- |
+ * | state | or | state |
+ *
+ * There's a hole, we need to insert something in it and
+ * ignore the extent we found.
+ */
+ if (state->start > start) {
+ u64 this_end;
+ if (end < last_start)
+ this_end = end;
+ else
+ this_end = last_start -1;
+ err = insert_state(tree, prealloc, start, this_end,
+ bits);
+ BUG_ON(err == -EEXIST);
+ prealloc = NULL;
+ if (err)
+ goto out;
+ start = this_end + 1;
+ goto search_again;
+ }
+ /*
+ * | ---- desired range ---- |
+ * | ---------- state ---------- |
+ * We need to split the extent, and set the bit
+ * on the first half
+ */
+ err = split_state(tree, state, prealloc, end + 1);
+ BUG_ON(err == -EEXIST);
+
+ state->state |= bits;
+ merge_state(tree, prealloc);
+ prealloc = NULL;
+out:
+ if (prealloc)
+ btrfs_free_extent_state(prealloc);
+ return err;
+search_again:
+ if (start > end)
+ goto out;
+ goto again;
+}
+
+int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end)
+{
+ return set_extent_bits(tree, start, end, EXTENT_DIRTY);
+}
+
+int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end)
+{
+ return clear_extent_bits(tree, start, end, EXTENT_DIRTY);
+}
+
+int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
+ u64 *start_ret, u64 *end_ret, int bits)
+{
+ struct cache_extent *node;
+ struct extent_state *state;
+ int ret = 1;
+
+ /*
+ * this search will find all the extents that end after
+ * our range starts.
+ */
+ node = search_cache_extent(&tree->state, start);
+ if (!node)
+ goto out;
+
+ while(1) {
+ state = container_of(node, struct extent_state, cache_node);
+ if (state->end >= start && (state->state & bits)) {
+ *start_ret = state->start;
+ *end_ret = state->end;
+ ret = 0;
+ break;
+ }
+ node = next_cache_extent(node);
+ if (!node)
+ break;
+ }
+out:
+ return ret;
+}
+
+int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
+ int bits, int filled)
+{
+ struct extent_state *state = NULL;
+ struct cache_extent *node;
+ int bitset = 0;
+
+ node = search_cache_extent(&tree->state, start);
+ while (node && start <= end) {
+ state = container_of(node, struct extent_state, cache_node);
+
+ if (filled && state->start > start) {
+ bitset = 0;
+ break;
+ }
+ if (state->start > end)
+ break;
+ if (state->state & bits) {
+ bitset = 1;
+ if (!filled)
+ break;
+ } else if (filled) {
+ bitset = 0;
+ break;
+ }
+ start = state->end + 1;
+ if (start > end)
+ break;
+ node = next_cache_extent(node);
+ if (!node) {
+ if (filled)
+ bitset = 0;
+ break;
+ }
+ }
+ return bitset;
+}
+
+int set_state_private(struct extent_io_tree *tree, u64 start, u64 private)
+{
+ struct cache_extent *node;
+ struct extent_state *state;
+ int ret = 0;
+
+ node = search_cache_extent(&tree->state, start);
+ if (!node) {
+ ret = -ENOENT;
+ goto out;
+ }
+ state = container_of(node, struct extent_state, cache_node);
+ if (state->start != start) {
+ ret = -ENOENT;
+ goto out;
+ }
+ state->xprivate = private;
+out:
+ return ret;
+}
+
+int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private)
+{
+ struct cache_extent *node;
+ struct extent_state *state;
+ int ret = 0;
+
+ node = search_cache_extent(&tree->state, start);
+ if (!node) {
+ ret = -ENOENT;
+ goto out;
+ }
+ state = container_of(node, struct extent_state, cache_node);
+ if (state->start != start) {
+ ret = -ENOENT;
+ goto out;
+ }
+ *private = state->xprivate;
+out:
+ return ret;
+}
+
+static struct extent_buffer *__alloc_extent_buffer(struct btrfs_fs_info *info,
+ u64 bytenr, u32 blocksize)
+{
+ struct extent_buffer *eb;
+
+ eb = calloc(1, sizeof(struct extent_buffer));
+ if (!eb)
+ return NULL;
+ eb->data = malloc_cache_aligned(blocksize);
+ if (!eb->data) {
+ free(eb);
+ return NULL;
+ }
+
+ eb->start = bytenr;
+ eb->len = blocksize;
+ eb->refs = 1;
+ eb->flags = 0;
+ eb->cache_node.start = bytenr;
+ eb->cache_node.size = blocksize;
+ eb->fs_info = info;
+ memset_extent_buffer(eb, 0, 0, blocksize);
+
+ return eb;
+}
+
+struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
+{
+ struct extent_buffer *new;
+
+ new = __alloc_extent_buffer(src->fs_info, src->start, src->len);
+ if (!new)
+ return NULL;
+
+ copy_extent_buffer(new, src, 0, 0, src->len);
+ new->flags |= EXTENT_BUFFER_DUMMY;
+
+ return new;
+}
+
+static void free_extent_buffer_final(struct extent_buffer *eb)
+{
+ BUG_ON(eb->refs);
+ if (!(eb->flags & EXTENT_BUFFER_DUMMY)) {
+ struct extent_io_tree *tree = &eb->fs_info->extent_cache;
+
+ remove_cache_extent(&tree->cache, &eb->cache_node);
+ BUG_ON(tree->cache_size < eb->len);
+ tree->cache_size -= eb->len;
+ }
+ free(eb->data);
+ free(eb);
+}
+
+static void free_extent_buffer_internal(struct extent_buffer *eb, bool free_now)
+{
+ if (!eb || IS_ERR(eb))
+ return;
+
+ eb->refs--;
+ BUG_ON(eb->refs < 0);
+ if (eb->refs == 0) {
+ if (eb->flags & EXTENT_DIRTY) {
+ error(
+ "dirty eb leak (aborted trans): start %llu len %u",
+ eb->start, eb->len);
+ }
+ if (eb->flags & EXTENT_BUFFER_DUMMY || free_now)
+ free_extent_buffer_final(eb);
+ }
+}
+
+void free_extent_buffer(struct extent_buffer *eb)
+{
+ free_extent_buffer_internal(eb, 1);
+}
+
+struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
+ u64 bytenr, u32 blocksize)
+{
+ struct extent_buffer *eb = NULL;
+ struct cache_extent *cache;
+
+ cache = lookup_cache_extent(&tree->cache, bytenr, blocksize);
+ if (cache && cache->start == bytenr &&
+ cache->size == blocksize) {
+ eb = container_of(cache, struct extent_buffer, cache_node);
+ eb->refs++;
+ }
+ return eb;
+}
+
+struct extent_buffer *find_first_extent_buffer(struct extent_io_tree *tree,
+ u64 start)
+{
+ struct extent_buffer *eb = NULL;
+ struct cache_extent *cache;
+
+ cache = search_cache_extent(&tree->cache, start);
+ if (cache) {
+ eb = container_of(cache, struct extent_buffer, cache_node);
+ eb->refs++;
+ }
+ return eb;
+}
+
+struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
+ u64 bytenr, u32 blocksize)
+{
+ struct extent_buffer *eb;
+ struct extent_io_tree *tree = &fs_info->extent_cache;
+ struct cache_extent *cache;
+
+ cache = lookup_cache_extent(&tree->cache, bytenr, blocksize);
+ if (cache && cache->start == bytenr &&
+ cache->size == blocksize) {
+ eb = container_of(cache, struct extent_buffer, cache_node);
+ eb->refs++;
+ } else {
+ int ret;
+
+ if (cache) {
+ eb = container_of(cache, struct extent_buffer,
+ cache_node);
+ free_extent_buffer(eb);
+ }
+ eb = __alloc_extent_buffer(fs_info, bytenr, blocksize);
+ if (!eb)
+ return NULL;
+ ret = insert_cache_extent(&tree->cache, &eb->cache_node);
+ if (ret) {
+ free(eb);
+ return NULL;
+ }
+ tree->cache_size += blocksize;
+ }
+ return eb;
+}
+
+/*
+ * Allocate a dummy extent buffer which won't be inserted into extent buffer
+ * cache.
+ *
+ * This mostly allows super block read write using existing eb infrastructure
+ * without pulluting the eb cache.
+ *
+ * This is especially important to avoid injecting eb->start == SZ_64K, as
+ * fuzzed image could have invalid tree bytenr covers super block range,
+ * and cause ref count underflow.
+ */
+struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
+ u64 bytenr, u32 blocksize)
+{
+ struct extent_buffer *ret;
+
+ ret = __alloc_extent_buffer(fs_info, bytenr, blocksize);
+ if (!ret)
+ return NULL;
+
+ ret->flags |= EXTENT_BUFFER_DUMMY;
+
+ return ret;
+}
+
+int read_extent_from_disk(struct blk_desc *desc, disk_partition_t *part,
+ u64 physical, struct extent_buffer *eb,
+ unsigned long offset, unsigned long len)
+{
+ int ret;
+
+ ret = __btrfs_devread(desc, part, eb->data + offset, len, physical);
+ if (ret < 0)
+ goto out;
+ if (ret != len) {
+ ret = -EIO;
+ goto out;
+ }
+ ret = 0;
+out:
+ return ret;
+}
+
+int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
+ unsigned long start, unsigned long len)
+{
+ return memcmp(eb->data + start, ptrv, len);
+}
+
+void read_extent_buffer(const struct extent_buffer *eb, void *dst,
+ unsigned long start, unsigned long len)
+{
+ memcpy(dst, eb->data + start, len);
+}
+
+void write_extent_buffer(struct extent_buffer *eb, const void *src,
+ unsigned long start, unsigned long len)
+{
+ memcpy(eb->data + start, src, len);
+}
+
+void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
+ unsigned long dst_offset, unsigned long src_offset,
+ unsigned long len)
+{
+ memcpy(dst->data + dst_offset, src->data + src_offset, len);
+}
+
+void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
+ unsigned long src_offset, unsigned long len)
+{
+ memmove(dst->data + dst_offset, dst->data + src_offset, len);
+}
+
+void memset_extent_buffer(struct extent_buffer *eb, char c,
+ unsigned long start, unsigned long len)
+{
+ memset(eb->data + start, c, len);
+}
+
+int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
+ unsigned long nr)
+{
+ return le_test_bit(nr, (u8 *)eb->data + start);
+}
+
+int set_extent_buffer_dirty(struct extent_buffer *eb)
+{
+ struct extent_io_tree *tree = &eb->fs_info->extent_cache;
+ if (!(eb->flags & EXTENT_DIRTY)) {
+ eb->flags |= EXTENT_DIRTY;
+ set_extent_dirty(tree, eb->start, eb->start + eb->len - 1);
+ extent_buffer_get(eb);
+ }
+ return 0;
+}
+
+int clear_extent_buffer_dirty(struct extent_buffer *eb)
+{
+ struct extent_io_tree *tree = &eb->fs_info->extent_cache;
+ if (eb->flags & EXTENT_DIRTY) {
+ eb->flags &= ~EXTENT_DIRTY;
+ clear_extent_dirty(tree, eb->start, eb->start + eb->len - 1);
+ free_extent_buffer(eb);
+ }
+ return 0;
+}
+
diff --git a/fs/btrfs/extent-io.h b/fs/btrfs/extent-io.h
new file mode 100644
index 000000000000..e8fb52b26b87
--- /dev/null
+++ b/fs/btrfs/extent-io.h
@@ -0,0 +1,164 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+/*
+ * Cross-ported from btrfs-progs/extent_io.h
+ *
+ * Modification includes:
+ * - extent_buffer:data
+ * Use pointer to provide better alignment.
+ * - Remove max_cache_size related interfaces
+ * Includes free_extent_buffer_nocache()
+ * As we don't cache eb in U-boot.
+ * - Include headers
+ *
+ * Write related functions are kept as we still need to modify dummy extent
+ * buffers even in RO environment.
+ */
+#ifndef __BTRFS_EXTENT_IO_H__
+#define __BTRFS_EXTENT_IO_H__
+
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/err.h>
+#include <linux/bitops.h>
+#include <fs_internal.h>
+#include "extent-cache.h"
+
+#define EXTENT_DIRTY (1U << 0)
+#define EXTENT_WRITEBACK (1U << 1)
+#define EXTENT_UPTODATE (1U << 2)
+#define EXTENT_LOCKED (1U << 3)
+#define EXTENT_NEW (1U << 4)
+#define EXTENT_DELALLOC (1U << 5)
+#define EXTENT_DEFRAG (1U << 6)
+#define EXTENT_DEFRAG_DONE (1U << 7)
+#define EXTENT_BUFFER_FILLED (1U << 8)
+#define EXTENT_CSUM (1U << 9)
+#define EXTENT_BAD_TRANSID (1U << 10)
+#define EXTENT_BUFFER_DUMMY (1U << 11)
+#define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK)
+
+#define BLOCK_GROUP_DATA (1U << 1)
+#define BLOCK_GROUP_METADATA (1U << 2)
+#define BLOCK_GROUP_SYSTEM (1U << 4)
+
+/*
+ * The extent buffer bitmap operations are done with byte granularity instead of
+ * word granularity for two reasons:
+ * 1. The bitmaps must be little-endian on disk.
+ * 2. Bitmap items are not guaranteed to be aligned to a word and therefore a
+ * single word in a bitmap may straddle two pages in the extent buffer.
+ */
+#define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE)
+#define BYTE_MASK ((1 << BITS_PER_BYTE) - 1)
+#define BITMAP_FIRST_BYTE_MASK(start) \
+ ((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK)
+#define BITMAP_LAST_BYTE_MASK(nbits) \
+ (BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1)))
+
+static inline int le_test_bit(int nr, const u8 *addr)
+{
+ return 1U & (addr[BIT_BYTE(nr)] >> (nr & (BITS_PER_BYTE-1)));
+}
+
+struct btrfs_fs_info;
+
+struct extent_io_tree {
+ struct cache_tree state;
+ struct cache_tree cache;
+ u64 cache_size;
+};
+
+struct extent_state {
+ struct cache_extent cache_node;
+ u64 start;
+ u64 end;
+ int refs;
+ unsigned long state;
+ u64 xprivate;
+};
+
+struct extent_buffer {
+ struct cache_extent cache_node;
+ u64 start;
+ u32 len;
+ int refs;
+ u32 flags;
+ struct btrfs_fs_info *fs_info;
+ char *data;
+};
+
+static inline void extent_buffer_get(struct extent_buffer *eb)
+{
+ eb->refs++;
+}
+
+void extent_io_tree_init(struct extent_io_tree *tree);
+void extent_io_tree_cleanup(struct extent_io_tree *tree);
+int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, int bits);
+int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, int bits);
+int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
+ u64 *start_ret, u64 *end_ret, int bits);
+int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
+ int bits, int filled);
+int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end);
+int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end);
+static inline int set_extent_buffer_uptodate(struct extent_buffer *eb)
+{
+ eb->flags |= EXTENT_UPTODATE;
+ return 0;
+}
+
+static inline int clear_extent_buffer_uptodate(struct extent_buffer *eb)
+{
+ eb->flags &= ~EXTENT_UPTODATE;
+ return 0;
+}
+
+static inline int extent_buffer_uptodate(struct extent_buffer *eb)
+{
+ if (!eb || IS_ERR(eb))
+ return 0;
+ if (eb->flags & EXTENT_UPTODATE)
+ return 1;
+ return 0;
+}
+
+int set_state_private(struct extent_io_tree *tree, u64 start, u64 xprivate);
+int get_state_private(struct extent_io_tree *tree, u64 start, u64 *xprivate);
+struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
+ u64 bytenr, u32 blocksize);
+struct extent_buffer *find_first_extent_buffer(struct extent_io_tree *tree,
+ u64 start);
+struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
+ u64 bytenr, u32 blocksize);
+struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src);
+struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
+ u64 bytenr, u32 blocksize);
+void free_extent_buffer(struct extent_buffer *eb);
+int read_extent_from_disk(struct blk_desc *desc, disk_partition_t *part,
+ u64 physical, struct extent_buffer *eb,
+ unsigned long offset, unsigned long len);
+int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
+ unsigned long start, unsigned long len);
+void read_extent_buffer(const struct extent_buffer *eb, void *dst,
+ unsigned long start, unsigned long len);
+void write_extent_buffer(struct extent_buffer *eb, const void *src,
+ unsigned long start, unsigned long len);
+void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
+ unsigned long dst_offset, unsigned long src_offset,
+ unsigned long len);
+void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
+ unsigned long src_offset, unsigned long len);
+void memset_extent_buffer(struct extent_buffer *eb, char c,
+ unsigned long start, unsigned long len);
+int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
+ unsigned long nr);
+int set_extent_buffer_dirty(struct extent_buffer *eb);
+int clear_extent_buffer_dirty(struct extent_buffer *eb);
+void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
+ unsigned long pos, unsigned long len);
+void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
+ unsigned long pos, unsigned long len);
+
+#endif
--
2.26.0