diff options
Diffstat (limited to 'drivers/block/zram/zcomp.c')
| -rw-r--r-- | drivers/block/zram/zcomp.c | 76 |
1 files changed, 47 insertions, 29 deletions
diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c index 400f8267337e..f35726860a1b 100644 --- a/drivers/block/zram/zcomp.c +++ b/drivers/block/zram/zcomp.c @@ -14,42 +14,39 @@ #include <linux/wait.h> #include <linux/sched.h> #include <linux/cpu.h> +#include <linux/crypto.h> #include "zcomp.h" -#include "zcomp_lzo.h" -#ifdef CONFIG_ZRAM_LZ4_COMPRESS -#include "zcomp_lz4.h" -#endif -static struct zcomp_backend *backends[] = { - &zcomp_lzo, +static const char * const backends[] = { + "lzo", #ifdef CONFIG_ZRAM_LZ4_COMPRESS - &zcomp_lz4, + "lz4", #endif NULL }; -static struct zcomp_backend *find_backend(const char *compress) +static const char *find_backend(const char *compress) { int i = 0; while (backends[i]) { - if (sysfs_streq(compress, backends[i]->name)) + if (sysfs_streq(compress, backends[i])) break; i++; } return backends[i]; } -static void zcomp_strm_free(struct zcomp *comp, struct zcomp_strm *zstrm) +static void zcomp_strm_free(struct zcomp_strm *zstrm) { - if (zstrm->private) - comp->backend->destroy(zstrm->private); + if (!IS_ERR_OR_NULL(zstrm->tfm)) + crypto_free_comp(zstrm->tfm); free_pages((unsigned long)zstrm->buffer, 1); kfree(zstrm); } /* - * allocate new zcomp_strm structure with ->private initialized by + * allocate new zcomp_strm structure with ->tfm initialized by * backend, return NULL on error */ static struct zcomp_strm *zcomp_strm_alloc(struct zcomp *comp, gfp_t flags) @@ -58,14 +55,14 @@ static struct zcomp_strm *zcomp_strm_alloc(struct zcomp *comp, gfp_t flags) if (!zstrm) return NULL; - zstrm->private = comp->backend->create(flags); + zstrm->tfm = crypto_alloc_comp(comp->name, 0, 0); /* * allocate 2 pages. 1 for compressed data, plus 1 extra for the * case when compressed size is larger than the original one */ zstrm->buffer = (void *)__get_free_pages(flags | __GFP_ZERO, 1); - if (!zstrm->private || !zstrm->buffer) { - zcomp_strm_free(comp, zstrm); + if (IS_ERR_OR_NULL(zstrm->tfm) || !zstrm->buffer) { + zcomp_strm_free(zstrm); zstrm = NULL; } return zstrm; @@ -78,12 +75,12 @@ ssize_t zcomp_available_show(const char *comp, char *buf) int i = 0; while (backends[i]) { - if (!strcmp(comp, backends[i]->name)) + if (!strcmp(comp, backends[i])) sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2, - "[%s] ", backends[i]->name); + "[%s] ", backends[i]); else sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2, - "%s ", backends[i]->name); + "%s ", backends[i]); i++; } sz += scnprintf(buf + sz, PAGE_SIZE - sz, "\n"); @@ -105,17 +102,38 @@ void zcomp_stream_put(struct zcomp *comp) put_cpu_ptr(comp->stream); } -int zcomp_compress(struct zcomp *comp, struct zcomp_strm *zstrm, - const unsigned char *src, size_t *dst_len) +int zcomp_compress(struct zcomp_strm *zstrm, + const void *src, unsigned int *dst_len) { - return comp->backend->compress(src, zstrm->buffer, dst_len, - zstrm->private); + /* + * Our dst memory (zstrm->buffer) is always `2 * PAGE_SIZE' sized + * because sometimes we can endup having a bigger compressed data + * due to various reasons: for example compression algorithms tend + * to add some padding to the compressed buffer. Speaking of padding, + * comp algorithm `842' pads the compressed length to multiple of 8 + * and returns -ENOSP when the dst memory is not big enough, which + * is not something that ZRAM wants to see. We can handle the + * `compressed_size > PAGE_SIZE' case easily in ZRAM, but when we + * receive -ERRNO from the compressing backend we can't help it + * anymore. To make `842' happy we need to tell the exact size of + * the dst buffer, zram_drv will take care of the fact that + * compressed buffer is too big. + */ + *dst_len = PAGE_SIZE * 2; + + return crypto_comp_compress(zstrm->tfm, + src, PAGE_SIZE, + zstrm->buffer, dst_len); } -int zcomp_decompress(struct zcomp *comp, const unsigned char *src, - size_t src_len, unsigned char *dst) +int zcomp_decompress(struct zcomp_strm *zstrm, + const void *src, unsigned int src_len, void *dst) { - return comp->backend->decompress(src, src_len, dst); + unsigned int dst_len = PAGE_SIZE; + + return crypto_comp_decompress(zstrm->tfm, + src, src_len, + dst, &dst_len); } static int __zcomp_cpu_notifier(struct zcomp *comp, @@ -138,7 +156,7 @@ static int __zcomp_cpu_notifier(struct zcomp *comp, case CPU_UP_CANCELED: zstrm = *per_cpu_ptr(comp->stream, cpu); if (!IS_ERR_OR_NULL(zstrm)) - zcomp_strm_free(comp, zstrm); + zcomp_strm_free(zstrm); *per_cpu_ptr(comp->stream, cpu) = NULL; break; default: @@ -209,7 +227,7 @@ void zcomp_destroy(struct zcomp *comp) struct zcomp *zcomp_create(const char *compress) { struct zcomp *comp; - struct zcomp_backend *backend; + const char *backend; int error; backend = find_backend(compress); @@ -220,7 +238,7 @@ struct zcomp *zcomp_create(const char *compress) if (!comp) return ERR_PTR(-ENOMEM); - comp->backend = backend; + comp->name = backend; error = zcomp_init(comp); if (error) { kfree(comp); |