Btrfs: check-integrity use bvec_iter

Some check-integrity code depends on bio->bi_vcnt, this changes it to use
bio segments because some bios passing here may not have a reliable
bi_vcnt.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
index 496eb00..6cabc8a 100644 (file)
--- a/fs/btrfs/check-integrity.c
+++ b/fs/btrfs/check-integrity.c
@@ -2816,44 +2816,47 @@ static void __btrfsic_submit_bio(struct bio *bio)
        dev_state = btrfsic_dev_state_lookup(bio->bi_bdev);
        if (NULL != dev_state &&
            (bio_op(bio) == REQ_OP_WRITE) && bio_has_data(bio)) {
-               unsigned int i;
+               unsigned int i = 0;
                u64 dev_bytenr;
                u64 cur_bytenr;
-               struct bio_vec *bvec;
+               struct bio_vec bvec;
+               struct bvec_iter iter;
                int bio_is_patched;
                char **mapped_datav;
+               unsigned int segs = bio_segments(bio);
 
                dev_bytenr = 512 * bio->bi_iter.bi_sector;
                bio_is_patched = 0;
                if (dev_state->state->print_mask &
                    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
                        pr_info("submit_bio(rw=%d,0x%x, bi_vcnt=%u, bi_sector=%llu (bytenr %llu), bi_bdev=%p)\n",
-                              bio_op(bio), bio->bi_opf, bio->bi_vcnt,
+                              bio_op(bio), bio->bi_opf, segs,
                               (unsigned long long)bio->bi_iter.bi_sector,
                               dev_bytenr, bio->bi_bdev);
 
-               mapped_datav = kmalloc_array(bio->bi_vcnt,
+               mapped_datav = kmalloc_array(segs,
                                             sizeof(*mapped_datav), GFP_NOFS);
                if (!mapped_datav)
                        goto leave;
                cur_bytenr = dev_bytenr;
 
-               bio_for_each_segment_all(bvec, bio, i) {
-                       BUG_ON(bvec->bv_len != PAGE_SIZE);
-                       mapped_datav[i] = kmap(bvec->bv_page);
+               bio_for_each_segment(bvec, bio, iter) {
+                       BUG_ON(bvec.bv_len != PAGE_SIZE);
+                       mapped_datav[i] = kmap(bvec.bv_page);
+                       i++;
 
                        if (dev_state->state->print_mask &
                            BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH_VERBOSE)
                                pr_info("#%u: bytenr=%llu, len=%u, offset=%u\n",
-                                      i, cur_bytenr, bvec->bv_len, bvec->bv_offset);
-                       cur_bytenr += bvec->bv_len;
+                                      i, cur_bytenr, bvec.bv_len, bvec.bv_offset);
+                       cur_bytenr += bvec.bv_len;
                }
                btrfsic_process_written_block(dev_state, dev_bytenr,
-                                             mapped_datav, bio->bi_vcnt,
+                                             mapped_datav, segs,
                                              bio, &bio_is_patched,
                                              NULL, bio->bi_opf);
-               bio_for_each_segment_all(bvec, bio, i)
-                       kunmap(bvec->bv_page);
+               bio_for_each_segment(bvec, bio, iter)
+                       kunmap(bvec.bv_page);
                kfree(mapped_datav);
        } else if (NULL != dev_state && (bio->bi_opf & REQ_PREFLUSH)) {
                if (dev_state->state->print_mask &