return bvec->bv_len != PAGE_SIZE;
}
-static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
- u32 index, int offset, struct bio *bio)
+static int zram_decompress_page(struct zram *zram, char *mem, u32 index)
{
- int ret;
- size_t clen;
- struct page *page;
- unsigned char *user_mem, *cmem, *uncmem = NULL;
-
- page = bvec->bv_page;
-
- if (zram_test_flag(zram, index, ZRAM_ZERO)) {
- handle_zero_page(bvec);
- return 0;
- }
+ int ret = LZO_E_OK;
+ size_t clen = PAGE_SIZE;
+ unsigned char *cmem;
+ unsigned long handle = zram->table[index].handle;
- /* Requested page is not present in compressed area */
- if (unlikely(!zram->table[index].handle)) {
- pr_debug("Read before write: sector=%lu, size=%u",
- (ulong)(bio->bi_sector), bio->bi_size);
- handle_zero_page(bvec);
+ if (!handle || zram_test_flag(zram, index, ZRAM_ZERO)) {
+ memset(mem, 0, PAGE_SIZE);
return 0;
}
- if (is_partial_io(bvec)) {
- /* Use a temporary buffer to decompress the page */
- uncmem = kmalloc(PAGE_SIZE, GFP_KERNEL);
- if (!uncmem) {
- pr_info("Error allocating temp memory!\n");
- return -ENOMEM;
- }
- }
-
- user_mem = kmap_atomic(page);
- if (!is_partial_io(bvec))
- uncmem = user_mem;
- clen = PAGE_SIZE;
-
- cmem = zs_map_object(zram->mem_pool, zram->table[index].handle,
- ZS_MM_RO);
-
- if (zram->table[index].size == PAGE_SIZE) {
- memcpy(uncmem, cmem, PAGE_SIZE);
- ret = LZO_E_OK;
- } else {
+ cmem = zs_map_object(zram->mem_pool, handle, ZS_MM_RO);
+ if (zram->table[index].size == PAGE_SIZE)
+ memcpy(mem, cmem, PAGE_SIZE);
+ else
ret = lzo1x_decompress_safe(cmem, zram->table[index].size,
- uncmem, &clen);
- }
-
- if (is_partial_io(bvec)) {
- memcpy(user_mem + bvec->bv_offset, uncmem + offset,
- bvec->bv_len);
- kfree(uncmem);
- }
-
- zs_unmap_object(zram->mem_pool, zram->table[index].handle);
- kunmap_atomic(user_mem);
+ mem, &clen);
+ zs_unmap_object(zram->mem_pool, handle);
/* Should NEVER happen. Return bio error if it does. */
if (unlikely(ret != LZO_E_OK)) {
return ret;
}
- flush_dcache_page(page);
-
return 0;
}
-static int zram_read_before_write(struct zram *zram, char *mem, u32 index)
+static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
+ u32 index, int offset, struct bio *bio)
{
int ret;
- size_t clen = PAGE_SIZE;
- unsigned char *cmem;
- unsigned long handle = zram->table[index].handle;
+ struct page *page;
+ unsigned char *user_mem, *uncmem = NULL;
- if (zram_test_flag(zram, index, ZRAM_ZERO) || !handle) {
- memset(mem, 0, PAGE_SIZE);
+ page = bvec->bv_page;
+
+ if (unlikely(!zram->table[index].handle) ||
+ zram_test_flag(zram, index, ZRAM_ZERO)) {
+ handle_zero_page(bvec);
return 0;
}
- cmem = zs_map_object(zram->mem_pool, handle, ZS_MM_RO);
- ret = lzo1x_decompress_safe(cmem, zram->table[index].size,
- mem, &clen);
- zs_unmap_object(zram->mem_pool, handle);
+ user_mem = kmap_atomic(page);
+ if (is_partial_io(bvec))
+ /* Use a temporary buffer to decompress the page */
+ uncmem = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ else
+ uncmem = user_mem;
+
+ if (!uncmem) {
+ pr_info("Unable to allocate temp memory\n");
+ ret = -ENOMEM;
+ goto out_cleanup;
+ }
+ ret = zram_decompress_page(zram, uncmem, index);
/* Should NEVER happen. Return bio error if it does. */
if (unlikely(ret != LZO_E_OK)) {
pr_err("Decompression failed! err=%d, page=%u\n", ret, index);
zram_stat64_inc(zram, &zram->stats.failed_reads);
- return ret;
+ goto out_cleanup;
}
- return 0;
+ if (is_partial_io(bvec))
+ memcpy(user_mem + bvec->bv_offset, uncmem + offset,
+ bvec->bv_len);
+
+ flush_dcache_page(page);
+ ret = 0;
+out_cleanup:
+ kunmap_atomic(user_mem);
+ if (is_partial_io(bvec))
+ kfree(uncmem);
+ return ret;
}
static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
int offset)
{
- int ret;
+ int ret = 0;
size_t clen;
unsigned long handle;
struct page *page;
ret = -ENOMEM;
goto out;
}
- ret = zram_read_before_write(zram, uncmem, index);
- if (ret) {
- kfree(uncmem);
+ ret = zram_decompress_page(zram, uncmem, index);
+ if (ret)
goto out;
- }
}
/*
user_mem = kmap_atomic(page);
- if (is_partial_io(bvec))
+ if (is_partial_io(bvec)) {
memcpy(uncmem + offset, user_mem + bvec->bv_offset,
bvec->bv_len);
- else
+ kunmap_atomic(user_mem);
+ user_mem = NULL;
+ } else {
uncmem = user_mem;
+ }
if (page_zero_filled(uncmem)) {
- kunmap_atomic(user_mem);
- if (is_partial_io(bvec))
- kfree(uncmem);
+ if (!is_partial_io(bvec))
+ kunmap_atomic(user_mem);
zram_stat_inc(&zram->stats.pages_zero);
zram_set_flag(zram, index, ZRAM_ZERO);
ret = 0;
ret = lzo1x_1_compress(uncmem, PAGE_SIZE, src, &clen,
zram->compress_workmem);
- kunmap_atomic(user_mem);
- if (is_partial_io(bvec))
- kfree(uncmem);
+ if (!is_partial_io(bvec)) {
+ kunmap_atomic(user_mem);
+ user_mem = NULL;
+ uncmem = NULL;
+ }
if (unlikely(ret != LZO_E_OK)) {
pr_err("Compression failed! err=%d\n", ret);
if (unlikely(clen > max_zpage_size)) {
zram_stat_inc(&zram->stats.bad_compress);
- src = uncmem;
clen = PAGE_SIZE;
+ src = NULL;
+ if (is_partial_io(bvec))
+ src = uncmem;
}
handle = zs_malloc(zram->mem_pool, clen);
}
cmem = zs_map_object(zram->mem_pool, handle, ZS_MM_WO);
+ if ((clen == PAGE_SIZE) && !is_partial_io(bvec))
+ src = kmap_atomic(page);
memcpy(cmem, src, clen);
+ if ((clen == PAGE_SIZE) && !is_partial_io(bvec))
+ kunmap_atomic(src);
zs_unmap_object(zram->mem_pool, handle);
if (clen <= PAGE_SIZE / 2)
zram_stat_inc(&zram->stats.good_compress);
- return 0;
-
out:
+ if (is_partial_io(bvec))
+ kfree(uncmem);
+
if (ret)
zram_stat64_inc(zram, &zram->stats.failed_writes);
return ret;
projects / firefly-linux-kernel-4.4.55.git / blobdiff