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- // SPDX-License-Identifier: GPL-2.0+
- /*
- * BTRFS filesystem implementation for U-Boot
- *
- * 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
- */
- #include <linux/kernel.h>
- #include <linux/bug.h>
- #include <malloc.h>
- #include <memalign.h>
- #include "btrfs.h"
- #include "ctree.h"
- #include "extent-io.h"
- #include "disk-io.h"
- 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, struct disk_partition *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;
- }
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