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authorGao Xiang <hsiangkao@linux.alibaba.com>2023-12-06 12:10:56 +0300
committerGao Xiang <hsiangkao@linux.alibaba.com>2023-12-18 10:49:39 +0300
commit1ca01520148af399899ed66af5c78330bb9ecaf2 (patch)
tree1bdfb6a5a112bba4197ed26abc81ce5af111d39d
parente5aba911dee5e20fa82efbe13e0af8f38ea459e7 (diff)
downloadlinux-1ca01520148af399899ed66af5c78330bb9ecaf2.tar.xz
erofs: refine z_erofs_transform_plain() for sub-page block support
Sub-page block support is still unusable even with previous commits if interlaced PLAIN pclusters exist. Such pclusters can be found if the fragment feature is enabled. This commit tries to handle "the head part" of interlaced PLAIN pclusters first: it was once explained in commit fdffc091e6f9 ("erofs: support interlaced uncompressed data for compressed files"). It uses a unique way for both shifted and interlaced PLAIN pclusters. As an added bonus, PLAIN pclusters larger than the block size is also supported now for the upcoming large lclusters. Reviewed-by: Yue Hu <huyue2@coolpad.com> Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com> Link: https://lore.kernel.org/r/20231206091057.87027-5-hsiangkao@linux.alibaba.com
-rw-r--r--fs/erofs/decompressor.c81
1 files changed, 48 insertions, 33 deletions
diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
index e0d609c3958f..d08a6ee23ac5 100644
--- a/fs/erofs/decompressor.c
+++ b/fs/erofs/decompressor.c
@@ -320,43 +320,58 @@ dstmap_out:
static int z_erofs_transform_plain(struct z_erofs_decompress_req *rq,
struct page **pagepool)
{
- const unsigned int inpages = PAGE_ALIGN(rq->inputsize) >> PAGE_SHIFT;
- const unsigned int outpages =
+ const unsigned int nrpages_in =
+ PAGE_ALIGN(rq->pageofs_in + rq->inputsize) >> PAGE_SHIFT;
+ const unsigned int nrpages_out =
PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
- const unsigned int righthalf = min_t(unsigned int, rq->outputsize,
- PAGE_SIZE - rq->pageofs_out);
- const unsigned int lefthalf = rq->outputsize - righthalf;
- const unsigned int interlaced_offset =
- rq->alg == Z_EROFS_COMPRESSION_SHIFTED ? 0 : rq->pageofs_out;
- u8 *src;
-
- if (outpages > 2 && rq->alg == Z_EROFS_COMPRESSION_SHIFTED) {
- DBG_BUGON(1);
- return -EFSCORRUPTED;
- }
-
- if (rq->out[0] == *rq->in) {
- DBG_BUGON(rq->pageofs_out);
- return 0;
+ const unsigned int bs = rq->sb->s_blocksize;
+ unsigned int cur = 0, ni = 0, no, pi, po, insz, cnt;
+ u8 *kin;
+
+ DBG_BUGON(rq->outputsize > rq->inputsize);
+ if (rq->alg == Z_EROFS_COMPRESSION_INTERLACED) {
+ cur = bs - (rq->pageofs_out & (bs - 1));
+ pi = (rq->pageofs_in + rq->inputsize - cur) & ~PAGE_MASK;
+ cur = min(cur, rq->outputsize);
+ if (cur && rq->out[0]) {
+ kin = kmap_local_page(rq->in[nrpages_in - 1]);
+ if (rq->out[0] == rq->in[nrpages_in - 1]) {
+ memmove(kin + rq->pageofs_out, kin + pi, cur);
+ flush_dcache_page(rq->out[0]);
+ } else {
+ memcpy_to_page(rq->out[0], rq->pageofs_out,
+ kin + pi, cur);
+ }
+ kunmap_local(kin);
+ }
+ rq->outputsize -= cur;
}
- src = kmap_local_page(rq->in[inpages - 1]) + rq->pageofs_in;
- if (rq->out[0])
- memcpy_to_page(rq->out[0], rq->pageofs_out,
- src + interlaced_offset, righthalf);
-
- if (outpages > inpages) {
- DBG_BUGON(!rq->out[outpages - 1]);
- if (rq->out[outpages - 1] != rq->in[inpages - 1]) {
- memcpy_to_page(rq->out[outpages - 1], 0, src +
- (interlaced_offset ? 0 : righthalf),
- lefthalf);
- } else if (!interlaced_offset) {
- memmove(src, src + righthalf, lefthalf);
- flush_dcache_page(rq->in[inpages - 1]);
- }
+ for (; rq->outputsize; rq->pageofs_in = 0, cur += PAGE_SIZE, ni++) {
+ insz = min(PAGE_SIZE - rq->pageofs_in, rq->outputsize);
+ rq->outputsize -= insz;
+ if (!rq->in[ni])
+ continue;
+ kin = kmap_local_page(rq->in[ni]);
+ pi = 0;
+ do {
+ no = (rq->pageofs_out + cur + pi) >> PAGE_SHIFT;
+ po = (rq->pageofs_out + cur + pi) & ~PAGE_MASK;
+ DBG_BUGON(no >= nrpages_out);
+ cnt = min(insz - pi, PAGE_SIZE - po);
+ if (rq->out[no] == rq->in[ni]) {
+ memmove(kin + po,
+ kin + rq->pageofs_in + pi, cnt);
+ flush_dcache_page(rq->out[no]);
+ } else if (rq->out[no]) {
+ memcpy_to_page(rq->out[no], po,
+ kin + rq->pageofs_in + pi, cnt);
+ }
+ pi += cnt;
+ } while (pi < insz);
+ kunmap_local(kin);
}
- kunmap_local(src);
+ DBG_BUGON(ni > nrpages_in);
return 0;
}