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authorQu Wenruo <wqu@suse.com>2021-02-04 10:03:24 +0300
committerDavid Sterba <dsterba@suse.com>2021-02-22 19:15:27 +0300
commit04d4ba4c90759844fb4ffa735214c1c41508d2f7 (patch)
tree5051352ad48a4aa9310497d1448ec0fad103d144 /fs/btrfs
parentbe6a13613fd35602ea9e65d6634cf7af79f0a93d (diff)
downloadlinux-04d4ba4c90759844fb4ffa735214c1c41508d2f7.tar.xz
btrfs: make check_compressed_csum() to be subpage compatible
Currently check_compressed_csum() completely relies on sectorsize == PAGE_SIZE to do checksum verification for compressed extents. To make it subpage compatible, this patch will: - Do extra calculation for the csum range Since we have multiple sectors inside a page, we need to only hash the range we want, not the full page anymore. - Do sector-by-sector hash inside the page With this patch and previous conversion on btrfs_submit_compressed_read(), now we can read subpage compressed extents properly, and do proper csum verification. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs')
-rw-r--r--fs/btrfs/compression.c39
1 files changed, 26 insertions, 13 deletions
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 5bad3a0b8a88..375dee691a37 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -141,6 +141,7 @@ static int check_compressed_csum(struct btrfs_inode *inode, struct bio *bio,
struct btrfs_fs_info *fs_info = inode->root->fs_info;
SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
const u32 csum_size = fs_info->csum_size;
+ const u32 sectorsize = fs_info->sectorsize;
struct page *page;
unsigned long i;
char *kaddr;
@@ -154,22 +155,34 @@ static int check_compressed_csum(struct btrfs_inode *inode, struct bio *bio,
shash->tfm = fs_info->csum_shash;
for (i = 0; i < cb->nr_pages; i++) {
+ u32 pg_offset;
+ u32 bytes_left = PAGE_SIZE;
page = cb->compressed_pages[i];
- kaddr = kmap_atomic(page);
- crypto_shash_digest(shash, kaddr, PAGE_SIZE, csum);
- kunmap_atomic(kaddr);
-
- if (memcmp(&csum, cb_sum, csum_size)) {
- btrfs_print_data_csum_error(inode, disk_start,
- csum, cb_sum, cb->mirror_num);
- if (btrfs_io_bio(bio)->device)
- btrfs_dev_stat_inc_and_print(
- btrfs_io_bio(bio)->device,
- BTRFS_DEV_STAT_CORRUPTION_ERRS);
- return -EIO;
+ /* Determine the remaining bytes inside the page first */
+ if (i == cb->nr_pages - 1)
+ bytes_left = cb->compressed_len - i * PAGE_SIZE;
+
+ /* Hash through the page sector by sector */
+ for (pg_offset = 0; pg_offset < bytes_left;
+ pg_offset += sectorsize) {
+ kaddr = kmap_atomic(page);
+ crypto_shash_digest(shash, kaddr + pg_offset,
+ sectorsize, csum);
+ kunmap_atomic(kaddr);
+
+ if (memcmp(&csum, cb_sum, csum_size) != 0) {
+ btrfs_print_data_csum_error(inode, disk_start,
+ csum, cb_sum, cb->mirror_num);
+ if (btrfs_io_bio(bio)->device)
+ btrfs_dev_stat_inc_and_print(
+ btrfs_io_bio(bio)->device,
+ BTRFS_DEV_STAT_CORRUPTION_ERRS);
+ return -EIO;
+ }
+ cb_sum += csum_size;
+ disk_start += sectorsize;
}
- cb_sum += csum_size;
}
return 0;
}