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|
/*
* BSD 3-Clause New License (https://spdx.org/licenses/BSD-3-Clause.html)
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Copyright (c) 2016-2018, Klara Inc.
* Copyright (c) 2016-2018, Allan Jude
* Copyright (c) 2018-2020, Sebastian Gottschall
* Copyright (c) 2019-2020, Michael Niewöhner
* Copyright (c) 2020, The FreeBSD Foundation [1]
*
* [1] Portions of this software were developed by Allan Jude
* under sponsorship from the FreeBSD Foundation.
*/
#include <sys/param.h>
#include <sys/sysmacros.h>
#include <sys/zfs_context.h>
#include <sys/zio_compress.h>
#include <sys/spa.h>
#include <sys/zstd/zstd.h>
#define ZSTD_STATIC_LINKING_ONLY
#include "lib/zstd.h"
#include "lib/zstd_errors.h"
kstat_t *zstd_ksp = NULL;
typedef struct zstd_stats {
kstat_named_t zstd_stat_alloc_fail;
kstat_named_t zstd_stat_alloc_fallback;
kstat_named_t zstd_stat_com_alloc_fail;
kstat_named_t zstd_stat_dec_alloc_fail;
kstat_named_t zstd_stat_com_inval;
kstat_named_t zstd_stat_dec_inval;
kstat_named_t zstd_stat_dec_header_inval;
kstat_named_t zstd_stat_com_fail;
kstat_named_t zstd_stat_dec_fail;
kstat_named_t zstd_stat_buffers;
kstat_named_t zstd_stat_size;
} zstd_stats_t;
static zstd_stats_t zstd_stats = {
{ "alloc_fail", KSTAT_DATA_UINT64 },
{ "alloc_fallback", KSTAT_DATA_UINT64 },
{ "compress_alloc_fail", KSTAT_DATA_UINT64 },
{ "decompress_alloc_fail", KSTAT_DATA_UINT64 },
{ "compress_level_invalid", KSTAT_DATA_UINT64 },
{ "decompress_level_invalid", KSTAT_DATA_UINT64 },
{ "decompress_header_invalid", KSTAT_DATA_UINT64 },
{ "compress_failed", KSTAT_DATA_UINT64 },
{ "decompress_failed", KSTAT_DATA_UINT64 },
{ "buffers", KSTAT_DATA_UINT64 },
{ "size", KSTAT_DATA_UINT64 },
};
/* Enums describing the allocator type specified by kmem_type in zstd_kmem */
enum zstd_kmem_type {
ZSTD_KMEM_UNKNOWN = 0,
/* Allocation type using kmem_vmalloc */
ZSTD_KMEM_DEFAULT,
/* Pool based allocation using mempool_alloc */
ZSTD_KMEM_POOL,
/* Reserved fallback memory for decompression only */
ZSTD_KMEM_DCTX,
ZSTD_KMEM_COUNT,
};
/* Structure for pooled memory objects */
struct zstd_pool {
void *mem;
size_t size;
kmutex_t barrier;
hrtime_t timeout;
};
/* Global structure for handling memory allocations */
struct zstd_kmem {
enum zstd_kmem_type kmem_type;
size_t kmem_size;
struct zstd_pool *pool;
};
/* Fallback memory structure used for decompression only if memory runs out */
struct zstd_fallback_mem {
size_t mem_size;
void *mem;
kmutex_t barrier;
};
struct zstd_levelmap {
int16_t zstd_level;
enum zio_zstd_levels level;
};
/*
* ZSTD memory handlers
*
* For decompression we use a different handler which also provides fallback
* memory allocation in case memory runs out.
*
* The ZSTD handlers were split up for the most simplified implementation.
*/
static void *zstd_alloc(void *opaque, size_t size);
static void *zstd_dctx_alloc(void *opaque, size_t size);
static void zstd_free(void *opaque, void *ptr);
/* Compression memory handler */
static const ZSTD_customMem zstd_malloc = {
zstd_alloc,
zstd_free,
NULL,
};
/* Decompression memory handler */
static const ZSTD_customMem zstd_dctx_malloc = {
zstd_dctx_alloc,
zstd_free,
NULL,
};
/* Level map for converting ZFS internal levels to ZSTD levels and vice versa */
static struct zstd_levelmap zstd_levels[] = {
{ZIO_ZSTD_LEVEL_1, ZIO_ZSTD_LEVEL_1},
{ZIO_ZSTD_LEVEL_2, ZIO_ZSTD_LEVEL_2},
{ZIO_ZSTD_LEVEL_3, ZIO_ZSTD_LEVEL_3},
{ZIO_ZSTD_LEVEL_4, ZIO_ZSTD_LEVEL_4},
{ZIO_ZSTD_LEVEL_5, ZIO_ZSTD_LEVEL_5},
{ZIO_ZSTD_LEVEL_6, ZIO_ZSTD_LEVEL_6},
{ZIO_ZSTD_LEVEL_7, ZIO_ZSTD_LEVEL_7},
{ZIO_ZSTD_LEVEL_8, ZIO_ZSTD_LEVEL_8},
{ZIO_ZSTD_LEVEL_9, ZIO_ZSTD_LEVEL_9},
{ZIO_ZSTD_LEVEL_10, ZIO_ZSTD_LEVEL_10},
{ZIO_ZSTD_LEVEL_11, ZIO_ZSTD_LEVEL_11},
{ZIO_ZSTD_LEVEL_12, ZIO_ZSTD_LEVEL_12},
{ZIO_ZSTD_LEVEL_13, ZIO_ZSTD_LEVEL_13},
{ZIO_ZSTD_LEVEL_14, ZIO_ZSTD_LEVEL_14},
{ZIO_ZSTD_LEVEL_15, ZIO_ZSTD_LEVEL_15},
{ZIO_ZSTD_LEVEL_16, ZIO_ZSTD_LEVEL_16},
{ZIO_ZSTD_LEVEL_17, ZIO_ZSTD_LEVEL_17},
{ZIO_ZSTD_LEVEL_18, ZIO_ZSTD_LEVEL_18},
{ZIO_ZSTD_LEVEL_19, ZIO_ZSTD_LEVEL_19},
{-1, ZIO_ZSTD_LEVEL_FAST_1},
{-2, ZIO_ZSTD_LEVEL_FAST_2},
{-3, ZIO_ZSTD_LEVEL_FAST_3},
{-4, ZIO_ZSTD_LEVEL_FAST_4},
{-5, ZIO_ZSTD_LEVEL_FAST_5},
{-6, ZIO_ZSTD_LEVEL_FAST_6},
{-7, ZIO_ZSTD_LEVEL_FAST_7},
{-8, ZIO_ZSTD_LEVEL_FAST_8},
{-9, ZIO_ZSTD_LEVEL_FAST_9},
{-10, ZIO_ZSTD_LEVEL_FAST_10},
{-20, ZIO_ZSTD_LEVEL_FAST_20},
{-30, ZIO_ZSTD_LEVEL_FAST_30},
{-40, ZIO_ZSTD_LEVEL_FAST_40},
{-50, ZIO_ZSTD_LEVEL_FAST_50},
{-60, ZIO_ZSTD_LEVEL_FAST_60},
{-70, ZIO_ZSTD_LEVEL_FAST_70},
{-80, ZIO_ZSTD_LEVEL_FAST_80},
{-90, ZIO_ZSTD_LEVEL_FAST_90},
{-100, ZIO_ZSTD_LEVEL_FAST_100},
{-500, ZIO_ZSTD_LEVEL_FAST_500},
{-1000, ZIO_ZSTD_LEVEL_FAST_1000},
};
/*
* This variable represents the maximum count of the pool based on the number
* of CPUs plus some buffer. We default to cpu count * 4, see init_zstd.
*/
static int pool_count = 16;
#define ZSTD_POOL_MAX pool_count
#define ZSTD_POOL_TIMEOUT 60 * 2
static struct zstd_fallback_mem zstd_dctx_fallback;
static struct zstd_pool *zstd_mempool_cctx;
static struct zstd_pool *zstd_mempool_dctx;
static void
zstd_mempool_reap(struct zstd_pool *zstd_mempool)
{
struct zstd_pool *pool;
if (!zstd_mempool || !ZSTDSTAT(zstd_stat_buffers)) {
return;
}
/* free obsolete slots */
for (int i = 0; i < ZSTD_POOL_MAX; i++) {
pool = &zstd_mempool[i];
if (pool->mem && mutex_tryenter(&pool->barrier)) {
/* Free memory if unused object older than 2 minutes */
if (pool->mem && gethrestime_sec() > pool->timeout) {
vmem_free(pool->mem, pool->size);
ZSTDSTAT_SUB(zstd_stat_buffers, 1);
ZSTDSTAT_SUB(zstd_stat_size, pool->size);
pool->mem = NULL;
pool->size = 0;
pool->timeout = 0;
}
mutex_exit(&pool->barrier);
}
}
}
/*
* Try to get a cached allocated buffer from memory pool or allocate a new one
* if necessary. If a object is older than 2 minutes and does not fit the
* requested size, it will be released and a new cached entry will be allocated.
* If other pooled objects are detected without being used for 2 minutes, they
* will be released, too.
*
* The concept is that high frequency memory allocations of bigger objects are
* expensive. So if a lot of work is going on, allocations will be kept for a
* while and can be reused in that time frame.
*
* The scheduled release will be updated every time a object is reused.
*/
static void *
zstd_mempool_alloc(struct zstd_pool *zstd_mempool, size_t size)
{
struct zstd_pool *pool;
struct zstd_kmem *mem = NULL;
if (!zstd_mempool) {
return (NULL);
}
/* Seek for preallocated memory slot and free obsolete slots */
for (int i = 0; i < ZSTD_POOL_MAX; i++) {
pool = &zstd_mempool[i];
/*
* This lock is simply a marker for a pool object being in use.
* If it's already hold, it will be skipped.
*
* We need to create it before checking it to avoid race
* conditions caused by running in a threaded context.
*
* The lock is later released by zstd_mempool_free.
*/
if (mutex_tryenter(&pool->barrier)) {
/*
* Check if objects fits the size, if so we take it and
* update the timestamp.
*/
if (pool->mem && size <= pool->size) {
pool->timeout = gethrestime_sec() +
ZSTD_POOL_TIMEOUT;
mem = pool->mem;
return (mem);
}
mutex_exit(&pool->barrier);
}
}
/*
* If no preallocated slot was found, try to fill in a new one.
*
* We run a similar algorithm twice here to avoid pool fragmentation.
* The first one may generate holes in the list if objects get released.
* We always make sure that these holes get filled instead of adding new
* allocations constantly at the end.
*/
for (int i = 0; i < ZSTD_POOL_MAX; i++) {
pool = &zstd_mempool[i];
if (mutex_tryenter(&pool->barrier)) {
/* Object is free, try to allocate new one */
if (!pool->mem) {
mem = vmem_alloc(size, KM_SLEEP);
if (mem) {
ZSTDSTAT_ADD(zstd_stat_buffers, 1);
ZSTDSTAT_ADD(zstd_stat_size, size);
pool->mem = mem;
pool->size = size;
/* Keep track for later release */
mem->pool = pool;
mem->kmem_type = ZSTD_KMEM_POOL;
mem->kmem_size = size;
}
}
if (size <= pool->size) {
/* Update timestamp */
pool->timeout = gethrestime_sec() +
ZSTD_POOL_TIMEOUT;
return (pool->mem);
}
mutex_exit(&pool->barrier);
}
}
/*
* If the pool is full or the allocation failed, try lazy allocation
* instead.
*/
if (!mem) {
mem = vmem_alloc(size, KM_NOSLEEP);
if (mem) {
mem->pool = NULL;
mem->kmem_type = ZSTD_KMEM_DEFAULT;
mem->kmem_size = size;
}
}
return (mem);
}
/* Mark object as released by releasing the barrier mutex */
static void
zstd_mempool_free(struct zstd_kmem *z)
{
mutex_exit(&z->pool->barrier);
}
/* Convert ZFS internal enum to ZSTD level */
static int
zstd_enum_to_level(enum zio_zstd_levels level, int16_t *zstd_level)
{
if (level > 0 && level <= ZIO_ZSTD_LEVEL_19) {
*zstd_level = zstd_levels[level - 1].zstd_level;
return (0);
}
if (level >= ZIO_ZSTD_LEVEL_FAST_1 &&
level <= ZIO_ZSTD_LEVEL_FAST_1000) {
*zstd_level = zstd_levels[level - ZIO_ZSTD_LEVEL_FAST_1
+ ZIO_ZSTD_LEVEL_19].zstd_level;
return (0);
}
/* Invalid/unknown zfs compression enum - this should never happen. */
return (1);
}
/* Compress block using zstd */
size_t
zfs_zstd_compress(void *s_start, void *d_start, size_t s_len, size_t d_len,
int level)
{
size_t c_len;
int16_t zstd_level;
zfs_zstdhdr_t *hdr;
ZSTD_CCtx *cctx;
hdr = (zfs_zstdhdr_t *)d_start;
/* Skip compression if the specified level is invalid */
if (zstd_enum_to_level(level, &zstd_level)) {
ZSTDSTAT_BUMP(zstd_stat_com_inval);
return (s_len);
}
ASSERT3U(d_len, >=, sizeof (*hdr));
ASSERT3U(d_len, <=, s_len);
ASSERT3U(zstd_level, !=, 0);
cctx = ZSTD_createCCtx_advanced(zstd_malloc);
/*
* Out of kernel memory, gently fall through - this will disable
* compression in zio_compress_data
*/
if (!cctx) {
ZSTDSTAT_BUMP(zstd_stat_com_alloc_fail);
return (s_len);
}
/* Set the compression level */
ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, zstd_level);
/* Use the "magicless" zstd header which saves us 4 header bytes */
ZSTD_CCtx_setParameter(cctx, ZSTD_c_format, ZSTD_f_zstd1_magicless);
/*
* Disable redundant checksum calculation and content size storage since
* this is already done by ZFS itself.
*/
ZSTD_CCtx_setParameter(cctx, ZSTD_c_checksumFlag, 0);
ZSTD_CCtx_setParameter(cctx, ZSTD_c_contentSizeFlag, 0);
c_len = ZSTD_compress2(cctx,
hdr->data,
d_len - sizeof (*hdr),
s_start, s_len);
ZSTD_freeCCtx(cctx);
/* Error in the compression routine, disable compression. */
if (ZSTD_isError(c_len)) {
/*
* If we are aborting the compression because the saves are
* too small, that is not a failure. Everything else is a
* failure, so increment the compression failure counter.
*/
if (ZSTD_getErrorCode(c_len) != ZSTD_error_dstSize_tooSmall) {
ZSTDSTAT_BUMP(zstd_stat_com_fail);
}
return (s_len);
}
/*
* Encode the compressed buffer size at the start. We'll need this in
* decompression to counter the effects of padding which might be added
* to the compressed buffer and which, if unhandled, would confuse the
* hell out of our decompression function.
*/
hdr->c_len = BE_32(c_len);
/*
* Check version for overflow.
* The limit of 24 bits must not be exceeded. This allows a maximum
* version 1677.72.15 which we don't expect to be ever reached.
*/
ASSERT3U(ZSTD_VERSION_NUMBER, <=, 0xFFFFFF);
/*
* Encode the compression level as well. We may need to know the
* original compression level if compressed_arc is disabled, to match
* the compression settings to write this block to the L2ARC.
*
* Encode the actual level, so if the enum changes in the future, we
* will be compatible.
*
* The upper 24 bits store the ZSTD version to be able to provide
* future compatibility, since new versions might enhance the
* compression algorithm in a way, where the compressed data will
* change.
*
* As soon as such incompatibility occurs, handling code needs to be
* added, differentiating between the versions.
*/
hdr->version = ZSTD_VERSION_NUMBER;
hdr->level = level;
hdr->raw_version_level = BE_32(hdr->raw_version_level);
return (c_len + sizeof (*hdr));
}
/* Decompress block using zstd and return its stored level */
int
zfs_zstd_decompress_level(void *s_start, void *d_start, size_t s_len,
size_t d_len, uint8_t *level)
{
ZSTD_DCtx *dctx;
size_t result;
int16_t zstd_level;
uint32_t c_len;
const zfs_zstdhdr_t *hdr;
zfs_zstdhdr_t hdr_copy;
hdr = (const zfs_zstdhdr_t *)s_start;
c_len = BE_32(hdr->c_len);
/*
* Make a copy instead of directly converting the header, since we must
* not modify the original data that may be used again later.
*/
hdr_copy.raw_version_level = BE_32(hdr->raw_version_level);
/*
* NOTE: We ignore the ZSTD version for now. As soon as any
* incompatibility occurs, it has to be handled accordingly.
* The version can be accessed via `hdr_copy.version`.
*/
/*
* Convert and check the level
* An invalid level is a strong indicator for data corruption! In such
* case return an error so the upper layers can try to fix it.
*/
if (zstd_enum_to_level(hdr_copy.level, &zstd_level)) {
ZSTDSTAT_BUMP(zstd_stat_dec_inval);
return (1);
}
ASSERT3U(d_len, >=, s_len);
ASSERT3U(hdr_copy.level, !=, ZIO_COMPLEVEL_INHERIT);
/* Invalid compressed buffer size encoded at start */
if (c_len + sizeof (*hdr) > s_len) {
ZSTDSTAT_BUMP(zstd_stat_dec_header_inval);
return (1);
}
dctx = ZSTD_createDCtx_advanced(zstd_dctx_malloc);
if (!dctx) {
ZSTDSTAT_BUMP(zstd_stat_dec_alloc_fail);
return (1);
}
/* Set header type to "magicless" */
ZSTD_DCtx_setParameter(dctx, ZSTD_d_format, ZSTD_f_zstd1_magicless);
/* Decompress the data and release the context */
result = ZSTD_decompressDCtx(dctx, d_start, d_len, hdr->data, c_len);
ZSTD_freeDCtx(dctx);
/*
* Returns 0 on success (decompression function returned non-negative)
* and non-zero on failure (decompression function returned negative.
*/
if (ZSTD_isError(result)) {
ZSTDSTAT_BUMP(zstd_stat_dec_fail);
return (1);
}
if (level) {
*level = hdr_copy.level;
}
return (0);
}
/* Decompress datablock using zstd */
int
zfs_zstd_decompress(void *s_start, void *d_start, size_t s_len, size_t d_len,
int level __maybe_unused)
{
return (zfs_zstd_decompress_level(s_start, d_start, s_len, d_len,
NULL));
}
/* Allocator for zstd compression context using mempool_allocator */
static void *
zstd_alloc(void *opaque __maybe_unused, size_t size)
{
size_t nbytes = sizeof (struct zstd_kmem) + size;
struct zstd_kmem *z = NULL;
z = (struct zstd_kmem *)zstd_mempool_alloc(zstd_mempool_cctx, nbytes);
if (!z) {
ZSTDSTAT_BUMP(zstd_stat_alloc_fail);
return (NULL);
}
return ((void*)z + (sizeof (struct zstd_kmem)));
}
/*
* Allocator for zstd decompression context using mempool_allocator with
* fallback to reserved memory if allocation fails
*/
static void *
zstd_dctx_alloc(void *opaque __maybe_unused, size_t size)
{
size_t nbytes = sizeof (struct zstd_kmem) + size;
struct zstd_kmem *z = NULL;
enum zstd_kmem_type type = ZSTD_KMEM_DEFAULT;
z = (struct zstd_kmem *)zstd_mempool_alloc(zstd_mempool_dctx, nbytes);
if (!z) {
/* Try harder, decompression shall not fail */
z = vmem_alloc(nbytes, KM_SLEEP);
if (z) {
z->pool = NULL;
}
ZSTDSTAT_BUMP(zstd_stat_alloc_fail);
} else {
return ((void*)z + (sizeof (struct zstd_kmem)));
}
/* Fallback if everything fails */
if (!z) {
/*
* Barrier since we only can handle it in a single thread. All
* other following threads need to wait here until decompression
* is completed. zstd_free will release this barrier later.
*/
mutex_enter(&zstd_dctx_fallback.barrier);
z = zstd_dctx_fallback.mem;
type = ZSTD_KMEM_DCTX;
ZSTDSTAT_BUMP(zstd_stat_alloc_fallback);
}
/* Allocation should always be successful */
if (!z) {
return (NULL);
}
z->kmem_type = type;
z->kmem_size = nbytes;
return ((void*)z + (sizeof (struct zstd_kmem)));
}
/* Free allocated memory by its specific type */
static void
zstd_free(void *opaque __maybe_unused, void *ptr)
{
struct zstd_kmem *z = (ptr - sizeof (struct zstd_kmem));
enum zstd_kmem_type type;
ASSERT3U(z->kmem_type, <, ZSTD_KMEM_COUNT);
ASSERT3U(z->kmem_type, >, ZSTD_KMEM_UNKNOWN);
type = z->kmem_type;
switch (type) {
case ZSTD_KMEM_DEFAULT:
vmem_free(z, z->kmem_size);
break;
case ZSTD_KMEM_POOL:
zstd_mempool_free(z);
break;
case ZSTD_KMEM_DCTX:
mutex_exit(&zstd_dctx_fallback.barrier);
break;
default:
break;
}
}
/* Allocate fallback memory to ensure safe decompression */
static void __init
create_fallback_mem(struct zstd_fallback_mem *mem, size_t size)
{
mem->mem_size = size;
mem->mem = vmem_zalloc(mem->mem_size, KM_SLEEP);
mutex_init(&mem->barrier, NULL, MUTEX_DEFAULT, NULL);
}
/* Initialize memory pool barrier mutexes */
static void __init
zstd_mempool_init(void)
{
zstd_mempool_cctx = (struct zstd_pool *)
kmem_zalloc(ZSTD_POOL_MAX * sizeof (struct zstd_pool), KM_SLEEP);
zstd_mempool_dctx = (struct zstd_pool *)
kmem_zalloc(ZSTD_POOL_MAX * sizeof (struct zstd_pool), KM_SLEEP);
for (int i = 0; i < ZSTD_POOL_MAX; i++) {
mutex_init(&zstd_mempool_cctx[i].barrier, NULL,
MUTEX_DEFAULT, NULL);
mutex_init(&zstd_mempool_dctx[i].barrier, NULL,
MUTEX_DEFAULT, NULL);
}
}
/* Initialize zstd-related memory handling */
static int __init
zstd_meminit(void)
{
zstd_mempool_init();
/*
* Estimate the size of the fallback decompression context.
* The expected size on x64 with current ZSTD should be about 160 KB.
*/
create_fallback_mem(&zstd_dctx_fallback,
P2ROUNDUP(ZSTD_estimateDCtxSize() + sizeof (struct zstd_kmem),
PAGESIZE));
return (0);
}
/* Release object from pool and free memory */
static void __exit
release_pool(struct zstd_pool *pool)
{
mutex_destroy(&pool->barrier);
vmem_free(pool->mem, pool->size);
pool->mem = NULL;
pool->size = 0;
}
/* Release memory pool objects */
static void __exit
zstd_mempool_deinit(void)
{
for (int i = 0; i < ZSTD_POOL_MAX; i++) {
release_pool(&zstd_mempool_cctx[i]);
release_pool(&zstd_mempool_dctx[i]);
}
kmem_free(zstd_mempool_dctx, ZSTD_POOL_MAX * sizeof (struct zstd_pool));
kmem_free(zstd_mempool_cctx, ZSTD_POOL_MAX * sizeof (struct zstd_pool));
zstd_mempool_dctx = NULL;
zstd_mempool_cctx = NULL;
}
/* release unused memory from pool */
void
zfs_zstd_cache_reap_now(void)
{
/*
* calling alloc with zero size seeks
* and releases old unused objects
*/
zstd_mempool_reap(zstd_mempool_cctx);
zstd_mempool_reap(zstd_mempool_dctx);
}
extern int __init
zstd_init(void)
{
/* Set pool size by using maximum sane thread count * 4 */
pool_count = (boot_ncpus * 4);
zstd_meminit();
/* Initialize kstat */
zstd_ksp = kstat_create("zfs", 0, "zstd", "misc",
KSTAT_TYPE_NAMED, sizeof (zstd_stats) / sizeof (kstat_named_t),
KSTAT_FLAG_VIRTUAL);
if (zstd_ksp != NULL) {
zstd_ksp->ks_data = &zstd_stats;
kstat_install(zstd_ksp);
}
return (0);
}
extern void __exit
zstd_fini(void)
{
/* Deinitialize kstat */
if (zstd_ksp != NULL) {
kstat_delete(zstd_ksp);
zstd_ksp = NULL;
}
/* Release fallback memory */
vmem_free(zstd_dctx_fallback.mem, zstd_dctx_fallback.mem_size);
mutex_destroy(&zstd_dctx_fallback.barrier);
/* Deinit memory pool */
zstd_mempool_deinit();
}
#if defined(_KERNEL)
module_init(zstd_init);
module_exit(zstd_fini);
ZFS_MODULE_DESCRIPTION("ZSTD Compression for ZFS");
ZFS_MODULE_LICENSE("Dual BSD/GPL");
ZFS_MODULE_VERSION(ZSTD_VERSION_STRING);
EXPORT_SYMBOL(zfs_zstd_compress);
EXPORT_SYMBOL(zfs_zstd_decompress_level);
EXPORT_SYMBOL(zfs_zstd_decompress);
EXPORT_SYMBOL(zfs_zstd_cache_reap_now);
#endif
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