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// SPDX-License-Identifier: GPL-2.0
#include "bcachefs.h"
#include "checksum.h"
#include "compress.h"
#include "extents.h"
#include "io.h"
#include "super-io.h"
#include <linux/lz4.h>
#include <linux/zlib.h>
#include <linux/zstd.h>
/* Bounce buffer: */
struct bbuf {
void *b;
enum {
BB_NONE,
BB_VMAP,
BB_KMALLOC,
BB_VMALLOC,
BB_MEMPOOL,
} type;
int rw;
};
static struct bbuf __bounce_alloc(struct bch_fs *c, unsigned size, int rw)
{
void *b;
BUG_ON(size > c->sb.encoded_extent_max << 9);
b = kmalloc(size, GFP_NOIO|__GFP_NOWARN);
if (b)
return (struct bbuf) { .b = b, .type = BB_KMALLOC, .rw = rw };
b = mempool_alloc(&c->compression_bounce[rw], GFP_NOWAIT);
b = b ? page_address(b) : NULL;
if (b)
return (struct bbuf) { .b = b, .type = BB_MEMPOOL, .rw = rw };
b = vmalloc(size);
if (b)
return (struct bbuf) { .b = b, .type = BB_VMALLOC, .rw = rw };
b = mempool_alloc(&c->compression_bounce[rw], GFP_NOIO);
b = b ? page_address(b) : NULL;
if (b)
return (struct bbuf) { .b = b, .type = BB_MEMPOOL, .rw = rw };
BUG();
}
static struct bbuf __bio_map_or_bounce(struct bch_fs *c, struct bio *bio,
struct bvec_iter start, int rw)
{
struct bbuf ret;
struct bio_vec bv;
struct bvec_iter iter;
unsigned nr_pages = 0;
struct page *stack_pages[16];
struct page **pages = NULL;
bool first = true;
unsigned prev_end = PAGE_SIZE;
void *data;
BUG_ON(bvec_iter_sectors(start) > c->sb.encoded_extent_max);
#ifndef CONFIG_HIGHMEM
__bio_for_each_contig_segment(bv, bio, iter, start) {
if (bv.bv_len == start.bi_size)
return (struct bbuf) {
.b = page_address(bv.bv_page) + bv.bv_offset,
.type = BB_NONE, .rw = rw
};
}
#endif
__bio_for_each_segment(bv, bio, iter, start) {
if ((!first && bv.bv_offset) ||
prev_end != PAGE_SIZE)
goto bounce;
prev_end = bv.bv_offset + bv.bv_len;
nr_pages++;
}
BUG_ON(DIV_ROUND_UP(start.bi_size, PAGE_SIZE) > nr_pages);
pages = nr_pages > ARRAY_SIZE(stack_pages)
? kmalloc_array(nr_pages, sizeof(struct page *), GFP_NOIO)
: stack_pages;
if (!pages)
goto bounce;
nr_pages = 0;
__bio_for_each_segment(bv, bio, iter, start)
pages[nr_pages++] = bv.bv_page;
data = vmap(pages, nr_pages, VM_MAP, PAGE_KERNEL);
if (pages != stack_pages)
kfree(pages);
if (data)
return (struct bbuf) {
.b = data + bio_iter_offset(bio, start),
.type = BB_VMAP, .rw = rw
};
bounce:
ret = __bounce_alloc(c, start.bi_size, rw);
if (rw == READ)
memcpy_from_bio(ret.b, bio, start);
return ret;
}
static struct bbuf bio_map_or_bounce(struct bch_fs *c, struct bio *bio, int rw)
{
return __bio_map_or_bounce(c, bio, bio->bi_iter, rw);
}
static void bio_unmap_or_unbounce(struct bch_fs *c, struct bbuf buf)
{
switch (buf.type) {
case BB_NONE:
break;
case BB_VMAP:
vunmap((void *) ((unsigned long) buf.b & PAGE_MASK));
break;
case BB_KMALLOC:
kfree(buf.b);
break;
case BB_VMALLOC:
vfree(buf.b);
break;
case BB_MEMPOOL:
mempool_free(virt_to_page(buf.b),
&c->compression_bounce[buf.rw]);
break;
}
}
static inline void zlib_set_workspace(z_stream *strm, void *workspace)
{
#ifdef __KERNEL__
strm->workspace = workspace;
#endif
}
static int __bio_uncompress(struct bch_fs *c, struct bio *src,
void *dst_data, struct bch_extent_crc_unpacked crc)
{
struct bbuf src_data = { NULL };
size_t src_len = src->bi_iter.bi_size;
size_t dst_len = crc.uncompressed_size << 9;
void *workspace;
int ret;
src_data = bio_map_or_bounce(c, src, READ);
switch (crc.compression_type) {
case BCH_COMPRESSION_LZ4_OLD:
case BCH_COMPRESSION_LZ4:
ret = LZ4_decompress_safe_partial(src_data.b, dst_data,
src_len, dst_len, dst_len);
if (ret != dst_len)
goto err;
break;
case BCH_COMPRESSION_GZIP: {
z_stream strm = {
.next_in = src_data.b,
.avail_in = src_len,
.next_out = dst_data,
.avail_out = dst_len,
};
workspace = mempool_alloc(&c->decompress_workspace, GFP_NOIO);
zlib_set_workspace(&strm, workspace);
zlib_inflateInit2(&strm, -MAX_WBITS);
ret = zlib_inflate(&strm, Z_FINISH);
mempool_free(workspace, &c->decompress_workspace);
if (ret != Z_STREAM_END)
goto err;
break;
}
case BCH_COMPRESSION_ZSTD: {
ZSTD_DCtx *ctx;
size_t len;
workspace = mempool_alloc(&c->decompress_workspace, GFP_NOIO);
ctx = zstd_init_dctx(workspace, zstd_dctx_workspace_bound());
src_len = le32_to_cpup(src_data.b);
len = zstd_decompress_dctx(ctx,
dst_data, dst_len,
src_data.b + 4, src_len);
mempool_free(workspace, &c->decompress_workspace);
if (len != dst_len)
goto err;
break;
}
default:
BUG();
}
ret = 0;
out:
bio_unmap_or_unbounce(c, src_data);
return ret;
err:
ret = -EIO;
goto out;
}
int bch2_bio_uncompress_inplace(struct bch_fs *c, struct bio *bio,
struct bch_extent_crc_unpacked *crc)
{
struct bbuf data = { NULL };
size_t dst_len = crc->uncompressed_size << 9;
/* bio must own its pages: */
BUG_ON(!bio->bi_vcnt);
BUG_ON(DIV_ROUND_UP(crc->live_size, PAGE_SECTORS) > bio->bi_max_vecs);
if (crc->uncompressed_size > c->sb.encoded_extent_max ||
crc->compressed_size > c->sb.encoded_extent_max) {
bch_err(c, "error rewriting existing data: extent too big");
return -EIO;
}
data = __bounce_alloc(c, dst_len, WRITE);
if (__bio_uncompress(c, bio, data.b, *crc)) {
bch_err(c, "error rewriting existing data: decompression error");
bio_unmap_or_unbounce(c, data);
return -EIO;
}
/*
* might have to free existing pages and retry allocation from mempool -
* do this _after_ decompressing:
*/
bch2_bio_alloc_more_pages_pool(c, bio, crc->live_size << 9);
memcpy_to_bio(bio, bio->bi_iter, data.b + (crc->offset << 9));
crc->csum_type = 0;
crc->compression_type = 0;
crc->compressed_size = crc->live_size;
crc->uncompressed_size = crc->live_size;
crc->offset = 0;
crc->csum = (struct bch_csum) { 0, 0 };
bio_unmap_or_unbounce(c, data);
return 0;
}
int bch2_bio_uncompress(struct bch_fs *c, struct bio *src,
struct bio *dst, struct bvec_iter dst_iter,
struct bch_extent_crc_unpacked crc)
{
struct bbuf dst_data = { NULL };
size_t dst_len = crc.uncompressed_size << 9;
int ret = -ENOMEM;
if (crc.uncompressed_size > c->sb.encoded_extent_max ||
crc.compressed_size > c->sb.encoded_extent_max)
return -EIO;
dst_data = dst_len == dst_iter.bi_size
? __bio_map_or_bounce(c, dst, dst_iter, WRITE)
: __bounce_alloc(c, dst_len, WRITE);
ret = __bio_uncompress(c, src, dst_data.b, crc);
if (ret)
goto err;
if (dst_data.type != BB_NONE)
memcpy_to_bio(dst, dst_iter, dst_data.b + (crc.offset << 9));
err:
bio_unmap_or_unbounce(c, dst_data);
return ret;
}
static int attempt_compress(struct bch_fs *c,
void *workspace,
void *dst, size_t dst_len,
void *src, size_t src_len,
unsigned compression_type)
{
switch (compression_type) {
case BCH_COMPRESSION_LZ4: {
int len = src_len;
int ret = LZ4_compress_destSize(
src, dst,
&len, dst_len,
workspace);
if (len < src_len)
return -len;
return ret;
}
case BCH_COMPRESSION_GZIP: {
z_stream strm = {
.next_in = src,
.avail_in = src_len,
.next_out = dst,
.avail_out = dst_len,
};
zlib_set_workspace(&strm, workspace);
zlib_deflateInit2(&strm, Z_DEFAULT_COMPRESSION,
Z_DEFLATED, -MAX_WBITS, DEF_MEM_LEVEL,
Z_DEFAULT_STRATEGY);
if (zlib_deflate(&strm, Z_FINISH) != Z_STREAM_END)
return 0;
if (zlib_deflateEnd(&strm) != Z_OK)
return 0;
return strm.total_out;
}
case BCH_COMPRESSION_ZSTD: {
ZSTD_CCtx *ctx = zstd_init_cctx(workspace,
zstd_cctx_workspace_bound(&c->zstd_params.cParams));
size_t len = zstd_compress_cctx(ctx,
dst + 4, dst_len - 4,
src, src_len,
&c->zstd_params);
if (zstd_is_error(len))
return 0;
*((__le32 *) dst) = cpu_to_le32(len);
return len + 4;
}
default:
BUG();
}
}
static unsigned __bio_compress(struct bch_fs *c,
struct bio *dst, size_t *dst_len,
struct bio *src, size_t *src_len,
unsigned compression_type)
{
struct bbuf src_data = { NULL }, dst_data = { NULL };
void *workspace;
unsigned pad;
int ret = 0;
BUG_ON(compression_type >= BCH_COMPRESSION_NR);
BUG_ON(!mempool_initialized(&c->compress_workspace[compression_type]));
/* If it's only one block, don't bother trying to compress: */
if (bio_sectors(src) <= c->opts.block_size)
return 0;
dst_data = bio_map_or_bounce(c, dst, WRITE);
src_data = bio_map_or_bounce(c, src, READ);
workspace = mempool_alloc(&c->compress_workspace[compression_type], GFP_NOIO);
*src_len = src->bi_iter.bi_size;
*dst_len = dst->bi_iter.bi_size;
/*
* XXX: this algorithm sucks when the compression code doesn't tell us
* how much would fit, like LZ4 does:
*/
while (1) {
if (*src_len <= block_bytes(c)) {
ret = -1;
break;
}
ret = attempt_compress(c, workspace,
dst_data.b, *dst_len,
src_data.b, *src_len,
compression_type);
if (ret > 0) {
*dst_len = ret;
ret = 0;
break;
}
/* Didn't fit: should we retry with a smaller amount? */
if (*src_len <= *dst_len) {
ret = -1;
break;
}
/*
* If ret is negative, it's a hint as to how much data would fit
*/
BUG_ON(-ret >= *src_len);
if (ret < 0)
*src_len = -ret;
else
*src_len -= (*src_len - *dst_len) / 2;
*src_len = round_down(*src_len, block_bytes(c));
}
mempool_free(workspace, &c->compress_workspace[compression_type]);
if (ret)
goto err;
/* Didn't get smaller: */
if (round_up(*dst_len, block_bytes(c)) >= *src_len)
goto err;
pad = round_up(*dst_len, block_bytes(c)) - *dst_len;
memset(dst_data.b + *dst_len, 0, pad);
*dst_len += pad;
if (dst_data.type != BB_NONE)
memcpy_to_bio(dst, dst->bi_iter, dst_data.b);
BUG_ON(!*dst_len || *dst_len > dst->bi_iter.bi_size);
BUG_ON(!*src_len || *src_len > src->bi_iter.bi_size);
BUG_ON(*dst_len & (block_bytes(c) - 1));
BUG_ON(*src_len & (block_bytes(c) - 1));
out:
bio_unmap_or_unbounce(c, src_data);
bio_unmap_or_unbounce(c, dst_data);
return compression_type;
err:
compression_type = 0;
goto out;
}
unsigned bch2_bio_compress(struct bch_fs *c,
struct bio *dst, size_t *dst_len,
struct bio *src, size_t *src_len,
unsigned compression_type)
{
unsigned orig_dst = dst->bi_iter.bi_size;
unsigned orig_src = src->bi_iter.bi_size;
/* Don't consume more than BCH_ENCODED_EXTENT_MAX from @src: */
src->bi_iter.bi_size = min_t(unsigned, src->bi_iter.bi_size,
c->sb.encoded_extent_max << 9);
/* Don't generate a bigger output than input: */
dst->bi_iter.bi_size = min(dst->bi_iter.bi_size, src->bi_iter.bi_size);
if (compression_type == BCH_COMPRESSION_LZ4_OLD)
compression_type = BCH_COMPRESSION_LZ4;
compression_type =
__bio_compress(c, dst, dst_len, src, src_len, compression_type);
dst->bi_iter.bi_size = orig_dst;
src->bi_iter.bi_size = orig_src;
return compression_type;
}
static int __bch2_fs_compress_init(struct bch_fs *, u64);
#define BCH_FEATURE_NONE 0
static const unsigned bch2_compression_opt_to_feature[] = {
#define x(t) [BCH_COMPRESSION_OPT_##t] = BCH_FEATURE_##t,
BCH_COMPRESSION_TYPES()
#undef x
};
#undef BCH_FEATURE_NONE
static int __bch2_check_set_has_compressed_data(struct bch_fs *c, u64 f)
{
int ret = 0;
if ((c->sb.features & f) == f)
return 0;
mutex_lock(&c->sb_lock);
if ((c->sb.features & f) == f) {
mutex_unlock(&c->sb_lock);
return 0;
}
ret = __bch2_fs_compress_init(c, c->sb.features|f);
if (ret) {
mutex_unlock(&c->sb_lock);
return ret;
}
c->disk_sb.sb->features[0] |= cpu_to_le64(f);
bch2_write_super(c);
mutex_unlock(&c->sb_lock);
return 0;
}
int bch2_check_set_has_compressed_data(struct bch_fs *c,
unsigned compression_type)
{
BUG_ON(compression_type >= ARRAY_SIZE(bch2_compression_opt_to_feature));
return compression_type
? __bch2_check_set_has_compressed_data(c,
1ULL << bch2_compression_opt_to_feature[compression_type])
: 0;
}
void bch2_fs_compress_exit(struct bch_fs *c)
{
unsigned i;
mempool_exit(&c->decompress_workspace);
for (i = 0; i < ARRAY_SIZE(c->compress_workspace); i++)
mempool_exit(&c->compress_workspace[i]);
mempool_exit(&c->compression_bounce[WRITE]);
mempool_exit(&c->compression_bounce[READ]);
}
static int __bch2_fs_compress_init(struct bch_fs *c, u64 features)
{
size_t max_extent = c->sb.encoded_extent_max << 9;
size_t order = get_order(max_extent);
size_t decompress_workspace_size = 0;
bool decompress_workspace_needed;
ZSTD_parameters params = zstd_get_params(0, max_extent);
struct {
unsigned feature;
unsigned type;
size_t compress_workspace;
size_t decompress_workspace;
} compression_types[] = {
{ BCH_FEATURE_LZ4, BCH_COMPRESSION_LZ4, LZ4_MEM_COMPRESS, 0 },
{ BCH_FEATURE_GZIP, BCH_COMPRESSION_GZIP,
zlib_deflate_workspacesize(MAX_WBITS, DEF_MEM_LEVEL),
zlib_inflate_workspacesize(), },
{ BCH_FEATURE_ZSTD, BCH_COMPRESSION_ZSTD,
zstd_cctx_workspace_bound(¶ms.cParams),
zstd_dctx_workspace_bound() },
}, *i;
int ret = 0;
pr_verbose_init(c->opts, "");
c->zstd_params = params;
for (i = compression_types;
i < compression_types + ARRAY_SIZE(compression_types);
i++)
if (features & (1 << i->feature))
goto have_compressed;
goto out;
have_compressed:
if (!mempool_initialized(&c->compression_bounce[READ])) {
ret = mempool_init_page_pool(&c->compression_bounce[READ],
1, order);
if (ret)
goto out;
}
if (!mempool_initialized(&c->compression_bounce[WRITE])) {
ret = mempool_init_page_pool(&c->compression_bounce[WRITE],
1, order);
if (ret)
goto out;
}
for (i = compression_types;
i < compression_types + ARRAY_SIZE(compression_types);
i++) {
decompress_workspace_size =
max(decompress_workspace_size, i->decompress_workspace);
if (!(features & (1 << i->feature)))
continue;
if (i->decompress_workspace)
decompress_workspace_needed = true;
if (mempool_initialized(&c->compress_workspace[i->type]))
continue;
ret = mempool_init_kvpmalloc_pool(
&c->compress_workspace[i->type],
1, i->compress_workspace);
if (ret)
goto out;
}
ret = mempool_init_kmalloc_pool(
&c->decompress_workspace,
1, decompress_workspace_size);
if (ret)
goto out;
out:
pr_verbose_init(c->opts, "ret %i", ret);
return ret;
}
int bch2_fs_compress_init(struct bch_fs *c)
{
u64 f = c->sb.features;
if (c->opts.compression)
f |= 1ULL << bch2_compression_opt_to_feature[c->opts.compression];
if (c->opts.background_compression)
f |= 1ULL << bch2_compression_opt_to_feature[c->opts.background_compression];
return __bch2_fs_compress_init(c, f);
}
|