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Diffstat (limited to 'fs/erofs/decompressor.c')
-rw-r--r--fs/erofs/decompressor.c139
1 files changed, 44 insertions, 95 deletions
diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
index a5bc4b1b7813..bf37fc76b182 100644
--- a/fs/erofs/decompressor.c
+++ b/fs/erofs/decompressor.c
@@ -16,17 +16,6 @@
#define LZ4_DECOMPRESS_INPLACE_MARGIN(srcsize) (((srcsize) >> 8) + 32)
#endif
-struct z_erofs_decompressor {
- /*
- * if destpages have sparsed pages, fill them with bounce pages.
- * it also check whether destpages indicate continuous physical memory.
- */
- int (*prepare_destpages)(struct z_erofs_decompress_req *rq,
- struct list_head *pagepool);
- int (*decompress)(struct z_erofs_decompress_req *rq, u8 *out);
- char *name;
-};
-
int z_erofs_load_lz4_config(struct super_block *sb,
struct erofs_super_block *dsb,
struct z_erofs_lz4_cfgs *lz4, int size)
@@ -63,8 +52,12 @@ int z_erofs_load_lz4_config(struct super_block *sb,
return erofs_pcpubuf_growsize(sbi->lz4.max_pclusterblks);
}
-static int z_erofs_lz4_prepare_destpages(struct z_erofs_decompress_req *rq,
- struct list_head *pagepool)
+/*
+ * Fill all gaps with bounce pages if it's a sparse page list. Also check if
+ * all physical pages are consecutive, which can be seen for moderate CR.
+ */
+static int z_erofs_lz4_prepare_dstpages(struct z_erofs_decompress_req *rq,
+ struct page **pagepool)
{
const unsigned int nr =
PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
@@ -119,7 +112,7 @@ static int z_erofs_lz4_prepare_destpages(struct z_erofs_decompress_req *rq,
return kaddr ? 1 : 0;
}
-static void *z_erofs_handle_inplace_io(struct z_erofs_decompress_req *rq,
+static void *z_erofs_lz4_handle_inplace_io(struct z_erofs_decompress_req *rq,
void *inpage, unsigned int *inputmargin, int *maptype,
bool support_0padding)
{
@@ -189,7 +182,8 @@ docopy:
return src;
}
-static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq, u8 *out)
+static int z_erofs_lz4_decompress_mem(struct z_erofs_decompress_req *rq,
+ u8 *out)
{
unsigned int inputmargin;
u8 *headpage, *src;
@@ -216,8 +210,8 @@ static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq, u8 *out)
}
rq->inputsize -= inputmargin;
- src = z_erofs_handle_inplace_io(rq, headpage, &inputmargin, &maptype,
- support_0padding);
+ src = z_erofs_lz4_handle_inplace_io(rq, headpage, &inputmargin,
+ &maptype, support_0padding);
if (IS_ERR(src))
return PTR_ERR(src);
@@ -233,7 +227,6 @@ static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq, u8 *out)
erofs_err(rq->sb, "failed to decompress %d in[%u, %u] out[%u]",
ret, rq->inputsize, inputmargin, rq->outputsize);
- WARN_ON(1);
print_hex_dump(KERN_DEBUG, "[ in]: ", DUMP_PREFIX_OFFSET,
16, 1, src + inputmargin, rq->inputsize, true);
print_hex_dump(KERN_DEBUG, "[out]: ", DUMP_PREFIX_OFFSET,
@@ -242,6 +235,8 @@ static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq, u8 *out)
if (ret >= 0)
memset(out + ret, 0, rq->outputsize - ret);
ret = -EIO;
+ } else {
+ ret = 0;
}
if (maptype == 0) {
@@ -257,86 +252,25 @@ static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq, u8 *out)
return ret;
}
-static struct z_erofs_decompressor decompressors[] = {
- [Z_EROFS_COMPRESSION_SHIFTED] = {
- .name = "shifted"
- },
- [Z_EROFS_COMPRESSION_LZ4] = {
- .prepare_destpages = z_erofs_lz4_prepare_destpages,
- .decompress = z_erofs_lz4_decompress,
- .name = "lz4"
- },
-};
-
-static void copy_from_pcpubuf(struct page **out, const char *dst,
- unsigned short pageofs_out,
- unsigned int outputsize)
-{
- const char *end = dst + outputsize;
- const unsigned int righthalf = PAGE_SIZE - pageofs_out;
- const char *cur = dst - pageofs_out;
-
- while (cur < end) {
- struct page *const page = *out++;
-
- if (page) {
- char *buf = kmap_atomic(page);
-
- if (cur >= dst) {
- memcpy(buf, cur, min_t(uint, PAGE_SIZE,
- end - cur));
- } else {
- memcpy(buf + pageofs_out, cur + pageofs_out,
- min_t(uint, righthalf, end - cur));
- }
- kunmap_atomic(buf);
- }
- cur += PAGE_SIZE;
- }
-}
-
-static int z_erofs_decompress_generic(struct z_erofs_decompress_req *rq,
- struct list_head *pagepool)
+static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq,
+ struct page **pagepool)
{
const unsigned int nrpages_out =
PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
- const struct z_erofs_decompressor *alg = decompressors + rq->alg;
unsigned int dst_maptype;
void *dst;
int ret;
- /* two optimized fast paths only for non bigpcluster cases yet */
- if (rq->inputsize <= PAGE_SIZE) {
- if (nrpages_out == 1 && !rq->inplace_io) {
- DBG_BUGON(!*rq->out);
- dst = kmap_atomic(*rq->out);
- dst_maptype = 0;
- goto dstmap_out;
- }
-
- /*
- * For the case of small output size (especially much less
- * than PAGE_SIZE), memcpy the decompressed data rather than
- * compressed data is preferred.
- */
- if (rq->outputsize <= PAGE_SIZE * 7 / 8) {
- dst = erofs_get_pcpubuf(1);
- if (IS_ERR(dst))
- return PTR_ERR(dst);
-
- rq->inplace_io = false;
- ret = alg->decompress(rq, dst);
- if (!ret)
- copy_from_pcpubuf(rq->out, dst, rq->pageofs_out,
- rq->outputsize);
-
- erofs_put_pcpubuf(dst);
- return ret;
- }
+ /* one optimized fast path only for non bigpcluster cases yet */
+ if (rq->inputsize <= PAGE_SIZE && nrpages_out == 1 && !rq->inplace_io) {
+ DBG_BUGON(!*rq->out);
+ dst = kmap_atomic(*rq->out);
+ dst_maptype = 0;
+ goto dstmap_out;
}
/* general decoding path which can be used for all cases */
- ret = alg->prepare_destpages(rq, pagepool);
+ ret = z_erofs_lz4_prepare_dstpages(rq, pagepool);
if (ret < 0)
return ret;
if (ret) {
@@ -351,7 +285,7 @@ static int z_erofs_decompress_generic(struct z_erofs_decompress_req *rq,
dst_maptype = 2;
dstmap_out:
- ret = alg->decompress(rq, dst + rq->pageofs_out);
+ ret = z_erofs_lz4_decompress_mem(rq, dst + rq->pageofs_out);
if (!dst_maptype)
kunmap_atomic(dst);
@@ -360,8 +294,8 @@ dstmap_out:
return ret;
}
-static int z_erofs_shifted_transform(const struct z_erofs_decompress_req *rq,
- struct list_head *pagepool)
+static int z_erofs_shifted_transform(struct z_erofs_decompress_req *rq,
+ struct page **pagepool)
{
const unsigned int nrpages_out =
PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
@@ -399,10 +333,25 @@ static int z_erofs_shifted_transform(const struct z_erofs_decompress_req *rq,
return 0;
}
+static struct z_erofs_decompressor decompressors[] = {
+ [Z_EROFS_COMPRESSION_SHIFTED] = {
+ .decompress = z_erofs_shifted_transform,
+ .name = "shifted"
+ },
+ [Z_EROFS_COMPRESSION_LZ4] = {
+ .decompress = z_erofs_lz4_decompress,
+ .name = "lz4"
+ },
+#ifdef CONFIG_EROFS_FS_ZIP_LZMA
+ [Z_EROFS_COMPRESSION_LZMA] = {
+ .decompress = z_erofs_lzma_decompress,
+ .name = "lzma"
+ },
+#endif
+};
+
int z_erofs_decompress(struct z_erofs_decompress_req *rq,
- struct list_head *pagepool)
+ struct page **pagepool)
{
- if (rq->alg == Z_EROFS_COMPRESSION_SHIFTED)
- return z_erofs_shifted_transform(rq, pagepool);
- return z_erofs_decompress_generic(rq, pagepool);
+ return decompressors[rq->alg].decompress(rq, pagepool);
}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.