--- /dev/null
+From 7a6d16b5e3a16262873dd30dbf81944f53466dc9 Mon Sep 17 00:00:00 2001
+From: Gao Xiang <hsiangkao@linux.alibaba.com>
+Date: Mon, 11 Oct 2021 05:31:44 +0800
+Subject: [PATCH 1011/1012] 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.
+
+Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
+---
+ fs/erofs/decompressor.c | 63 ++++++++++++++++++++---------------------
+ 1 file changed, 30 insertions(+), 33 deletions(-)
+
+diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
+index dce06ac61..8fd7af9d6 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 @@ static void *z_erofs_handle_inplace_io(struct z_erofs_decompress_req *rq,
+ 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 @@ static int z_erofs_decompress_generic(struct z_erofs_decompress_req *rq,
+ 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);
+ }
+--
+2.32.0
+
projects / openwrt / staging / aparcar.git / blobdiff