f2fs: compress: support chksum
This patch supports to store chksum value with compressed
data, and verify the integrality of compressed data while
reading the data.
The feature can be enabled through specifying mount option
'compress_chksum'.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 14262e0..7ec1592 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -602,6 +602,7 @@ static int f2fs_compress_pages(struct compress_ctx *cc)
f2fs_cops[fi->i_compress_algorithm];
unsigned int max_len, new_nr_cpages;
struct page **new_cpages;
+ u32 chksum = 0;
int i, ret;
trace_f2fs_compress_pages_start(cc->inode, cc->cluster_idx,
@@ -655,6 +656,11 @@ static int f2fs_compress_pages(struct compress_ctx *cc)
cc->cbuf->clen = cpu_to_le32(cc->clen);
+ if (fi->i_compress_flag & 1 << COMPRESS_CHKSUM)
+ chksum = f2fs_crc32(F2FS_I_SB(cc->inode),
+ cc->cbuf->cdata, cc->clen);
+ cc->cbuf->chksum = cpu_to_le32(chksum);
+
for (i = 0; i < COMPRESS_DATA_RESERVED_SIZE; i++)
cc->cbuf->reserved[i] = cpu_to_le32(0);
@@ -790,6 +796,23 @@ void f2fs_decompress_pages(struct bio *bio, struct page *page, bool verity)
ret = cops->decompress_pages(dic);
+ if (!ret && fi->i_compress_flag & 1 << COMPRESS_CHKSUM) {
+ u32 provided = le32_to_cpu(dic->cbuf->chksum);
+ u32 calculated = f2fs_crc32(sbi, dic->cbuf->cdata, dic->clen);
+
+ if (provided != calculated) {
+ if (!is_inode_flag_set(dic->inode, FI_COMPRESS_CORRUPT)) {
+ set_inode_flag(dic->inode, FI_COMPRESS_CORRUPT);
+ printk_ratelimited(
+ "%sF2FS-fs (%s): checksum invalid, nid = %lu, %x vs %x",
+ KERN_INFO, sbi->sb->s_id, dic->inode->i_ino,
+ provided, calculated);
+ }
+ set_sbi_flag(sbi, SBI_NEED_FSCK);
+ WARN_ON_ONCE(1);
+ }
+ }
+
out_vunmap_cbuf:
vm_unmap_ram(dic->cbuf, dic->nr_cpages);
out_vunmap_rbuf:
