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authorGao Xiang <hsiangkao@linux.alibaba.com>2021-10-11 05:31:44 +0800
committerGao Xiang <hsiangkao@linux.alibaba.com>2021-10-19 23:44:30 +0800
commit966edfb0a3dc2adf5aab461c298fa0feb02f49d6 (patch)
tree1607637fa3e0edf3a2ae4b051caeec3cd76b77ec /fs/erofs/decompressor.c
parent0a434e0a2c9f4395e4560aac22677ef25ab4afd9 (diff)
erofs: rename some generic methods in decompressor
Previously, some LZ4 methods were named with `generic'. However, while evaluating the effective LZMA approach, it seems they aren't quite generic at all (e.g. no need preparing dstpages for most LZMA cases.) Avoid such naming instead. Link: https://lore.kernel.org/r/20211010213145.17462-7-xiang@kernel.org Acked-by: Chao Yu <chao@kernel.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Diffstat (limited to 'fs/erofs/decompressor.c')
-rw-r--r--fs/erofs/decompressor.c63
1 files changed, 30 insertions, 33 deletions
diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
index dce06ac61893..8fd7af9d6b38 100644
--- a/fs/erofs/decompressor.c
+++ b/fs/erofs/decompressor.c
@@ -17,13 +17,8 @@
#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);
+ int (*decompress)(struct z_erofs_decompress_req *rq,
+ struct list_head *pagepool);
char *name;
};
@@ -63,8 +58,12 @@ 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 list_head *pagepool)
{
const unsigned int nr =
PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
@@ -119,7 +118,7 @@ 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 +188,8 @@ 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 +216,8 @@ 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);
@@ -259,23 +259,11 @@ 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 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 list_head *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;
@@ -289,7 +277,7 @@ static int z_erofs_decompress_generic(struct z_erofs_decompress_req *rq,
}
/* 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) {
@@ -304,7 +292,7 @@ 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);
@@ -313,7 +301,7 @@ dstmap_out:
return ret;
}
-static int z_erofs_shifted_transform(const struct z_erofs_decompress_req *rq,
+static int z_erofs_shifted_transform(struct z_erofs_decompress_req *rq,
struct list_head *pagepool)
{
const unsigned int nrpages_out =
@@ -352,10 +340,19 @@ 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"
+ },
+};
+
int z_erofs_decompress(struct z_erofs_decompress_req *rq,
struct list_head *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);
}