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-rw-r--r--fs/erofs/decompressor.c218
-rw-r--r--fs/erofs/internal.h15
2 files changed, 138 insertions, 95 deletions
diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
index 900de4725d35..88e33addf229 100644
--- a/fs/erofs/decompressor.c
+++ b/fs/erofs/decompressor.c
@@ -120,44 +120,85 @@ static int z_erofs_lz4_prepare_destpages(struct z_erofs_decompress_req *rq,
return kaddr ? 1 : 0;
}
-static void *generic_copy_inplace_data(struct z_erofs_decompress_req *rq,
- u8 *src, unsigned int pageofs_in)
+static void *z_erofs_handle_inplace_io(struct z_erofs_decompress_req *rq,
+ void *inpage, unsigned int *inputmargin, int *maptype,
+ bool support_0padding)
{
- /*
- * if in-place decompression is ongoing, those decompressed
- * pages should be copied in order to avoid being overlapped.
- */
- struct page **in = rq->in;
- u8 *const tmp = erofs_get_pcpubuf(1);
- u8 *tmpp = tmp;
- unsigned int inlen = rq->inputsize - pageofs_in;
- unsigned int count = min_t(uint, inlen, PAGE_SIZE - pageofs_in);
-
- while (tmpp < tmp + inlen) {
- if (!src)
- src = kmap_atomic(*in);
- memcpy(tmpp, src + pageofs_in, count);
- kunmap_atomic(src);
- src = NULL;
- tmpp += count;
- pageofs_in = 0;
- count = PAGE_SIZE;
+ unsigned int nrpages_in, nrpages_out;
+ unsigned int ofull, oend, inputsize, total, i, j;
+ struct page **in;
+ void *src, *tmp;
+
+ inputsize = rq->inputsize;
+ nrpages_in = PAGE_ALIGN(inputsize) >> PAGE_SHIFT;
+ oend = rq->pageofs_out + rq->outputsize;
+ ofull = PAGE_ALIGN(oend);
+ nrpages_out = ofull >> PAGE_SHIFT;
+
+ if (rq->inplace_io) {
+ if (rq->partial_decoding || !support_0padding ||
+ ofull - oend < LZ4_DECOMPRESS_INPLACE_MARGIN(inputsize))
+ goto docopy;
+
+ for (i = 0; i < nrpages_in; ++i) {
+ DBG_BUGON(rq->in[i] == NULL);
+ for (j = 0; j < nrpages_out - nrpages_in + i; ++j)
+ if (rq->out[j] == rq->in[i])
+ goto docopy;
+ }
+ }
+
+ if (nrpages_in <= 1) {
+ *maptype = 0;
+ return inpage;
+ }
+ kunmap_atomic(inpage);
+ might_sleep();
+ src = erofs_vm_map_ram(rq->in, nrpages_in);
+ if (!src)
+ return ERR_PTR(-ENOMEM);
+ *maptype = 1;
+ return src;
+
+docopy:
+ /* Or copy compressed data which can be overlapped to per-CPU buffer */
+ in = rq->in;
+ src = erofs_get_pcpubuf(nrpages_in);
+ if (!src) {
+ DBG_BUGON(1);
+ kunmap_atomic(inpage);
+ return ERR_PTR(-EFAULT);
+ }
+
+ tmp = src;
+ total = rq->inputsize;
+ while (total) {
+ unsigned int page_copycnt =
+ min_t(unsigned int, total, PAGE_SIZE - *inputmargin);
+
+ if (!inpage)
+ inpage = kmap_atomic(*in);
+ memcpy(tmp, inpage + *inputmargin, page_copycnt);
+ kunmap_atomic(inpage);
+ inpage = NULL;
+ tmp += page_copycnt;
+ total -= page_copycnt;
++in;
+ *inputmargin = 0;
}
- return tmp;
+ *maptype = 2;
+ return src;
}
static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq, u8 *out)
{
- unsigned int inputmargin, inlen;
- u8 *src;
- bool copied, support_0padding;
- int ret;
-
- if (rq->inputsize > PAGE_SIZE)
- return -EOPNOTSUPP;
+ unsigned int inputmargin;
+ u8 *headpage, *src;
+ bool support_0padding;
+ int ret, maptype;
- src = kmap_atomic(*rq->in);
+ DBG_BUGON(*rq->in == NULL);
+ headpage = kmap_atomic(*rq->in);
inputmargin = 0;
support_0padding = false;
@@ -165,50 +206,37 @@ static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq, u8 *out)
if (erofs_sb_has_lz4_0padding(EROFS_SB(rq->sb))) {
support_0padding = true;
- while (!src[inputmargin & ~PAGE_MASK])
+ while (!headpage[inputmargin & ~PAGE_MASK])
if (!(++inputmargin & ~PAGE_MASK))
break;
if (inputmargin >= rq->inputsize) {
- kunmap_atomic(src);
+ kunmap_atomic(headpage);
return -EIO;
}
}
- copied = false;
- inlen = rq->inputsize - inputmargin;
- if (rq->inplace_io) {
- const uint oend = (rq->pageofs_out +
- rq->outputsize) & ~PAGE_MASK;
- const uint nr = PAGE_ALIGN(rq->pageofs_out +
- rq->outputsize) >> PAGE_SHIFT;
-
- if (rq->partial_decoding || !support_0padding ||
- rq->out[nr - 1] != rq->in[0] ||
- rq->inputsize - oend <
- LZ4_DECOMPRESS_INPLACE_MARGIN(inlen)) {
- src = generic_copy_inplace_data(rq, src, inputmargin);
- inputmargin = 0;
- copied = true;
- }
- }
+ rq->inputsize -= inputmargin;
+ src = z_erofs_handle_inplace_io(rq, headpage, &inputmargin, &maptype,
+ support_0padding);
+ if (IS_ERR(src))
+ return PTR_ERR(src);
/* legacy format could compress extra data in a pcluster. */
if (rq->partial_decoding || !support_0padding)
ret = LZ4_decompress_safe_partial(src + inputmargin, out,
- inlen, rq->outputsize,
- rq->outputsize);
+ rq->inputsize, rq->outputsize, rq->outputsize);
else
ret = LZ4_decompress_safe(src + inputmargin, out,
- inlen, rq->outputsize);
+ rq->inputsize, rq->outputsize);
if (ret != rq->outputsize) {
erofs_err(rq->sb, "failed to decompress %d in[%u, %u] out[%u]",
- ret, inlen, inputmargin, rq->outputsize);
+ ret, rq->inputsize, inputmargin, rq->outputsize);
WARN_ON(1);
print_hex_dump(KERN_DEBUG, "[ in]: ", DUMP_PREFIX_OFFSET,
- 16, 1, src + inputmargin, inlen, true);
+ 16, 1, src + inputmargin, rq->inputsize, true);
print_hex_dump(KERN_DEBUG, "[out]: ", DUMP_PREFIX_OFFSET,
16, 1, out, rq->outputsize, true);
@@ -217,10 +245,16 @@ static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq, u8 *out)
ret = -EIO;
}
- if (copied)
- erofs_put_pcpubuf(src);
- else
+ if (maptype == 0) {
kunmap_atomic(src);
+ } else if (maptype == 1) {
+ vm_unmap_ram(src, PAGE_ALIGN(rq->inputsize) >> PAGE_SHIFT);
+ } else if (maptype == 2) {
+ erofs_put_pcpubuf(src);
+ } else {
+ DBG_BUGON(1);
+ return -EFAULT;
+ }
return ret;
}
@@ -270,57 +304,51 @@ static int z_erofs_decompress_generic(struct z_erofs_decompress_req *rq,
const struct z_erofs_decompressor *alg = decompressors + rq->alg;
unsigned int dst_maptype;
void *dst;
- int ret, i;
+ int ret;
- if (nrpages_out == 1 && !rq->inplace_io) {
- DBG_BUGON(!*rq->out);
- dst = kmap_atomic(*rq->out);
- dst_maptype = 0;
- goto dstmap_out;
- }
+ /* 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;
+ /*
+ * 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;
+ }
}
+ /* general decoding path which can be used for all cases */
ret = alg->prepare_destpages(rq, pagepool);
- if (ret < 0) {
+ if (ret < 0)
return ret;
- } else if (ret) {
+ if (ret) {
dst = page_address(*rq->out);
dst_maptype = 1;
goto dstmap_out;
}
- i = 0;
- while (1) {
- dst = vm_map_ram(rq->out, nrpages_out, -1);
-
- /* retry two more times (totally 3 times) */
- if (dst || ++i >= 3)
- break;
- vm_unmap_aliases();
- }
-
+ dst = erofs_vm_map_ram(rq->out, nrpages_out);
if (!dst)
return -ENOMEM;
-
dst_maptype = 2;
dstmap_out:
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 5c2388daee6e..f92e3e32b9f4 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -402,6 +402,21 @@ int erofs_namei(struct inode *dir, struct qstr *name,
/* dir.c */
extern const struct file_operations erofs_dir_fops;
+static inline void *erofs_vm_map_ram(struct page **pages, unsigned int count)
+{
+ int retried = 0;
+
+ while (1) {
+ void *p = vm_map_ram(pages, count, -1);
+
+ /* retry two more times (totally 3 times) */
+ if (p || ++retried >= 3)
+ return p;
+ vm_unmap_aliases();
+ }
+ return NULL;
+}
+
/* pcpubuf.c */
void *erofs_get_pcpubuf(unsigned int requiredpages);
void erofs_put_pcpubuf(void *ptr);
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-14 10:53:51 +0000