btrfs: integrity-checker: use kmap_local_page in __btrfsic_submit_bio

Again there is an array of pointers which must be unmapped in the correct
order.

Convert the kmap()'s to kmap_local_page() and adjust the unmapping
to work backwards through the unmapping loop.

Signed-off-by: Ira Weiny <ira.weiny@intel.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 113cb85c1fd448a5cfd366301636a60cffacabad..6cc8296be030a0cf05c7acf05dc7b76279ef9a90 100644 (file)
--- a/fs/btrfs/check-integrity.c
+++ b/fs/btrfs/check-integrity.c
@@ -2677,7 +2677,7 @@ static void __btrfsic_submit_bio(struct bio *bio)
        dev_state = btrfsic_dev_state_lookup(bio->bi_bdev->bd_dev);
        if (NULL != dev_state &&
            (bio_op(bio) == REQ_OP_WRITE) && bio_has_data(bio)) {
-               unsigned int i = 0;
+               int i = 0;
                u64 dev_bytenr;
                u64 cur_bytenr;
                struct bio_vec bvec;
@@ -2702,7 +2702,7 @@ static void __btrfsic_submit_bio(struct bio *bio)
 
                bio_for_each_segment(bvec, bio, iter) {
                        BUG_ON(bvec.bv_len != PAGE_SIZE);
-                       mapped_datav[i] = kmap(bvec.bv_page);
+                       mapped_datav[i] = kmap_local_page(bvec.bv_page);
                        i++;
 
                        if (dev_state->state->print_mask &
@@ -2715,8 +2715,9 @@ static void __btrfsic_submit_bio(struct bio *bio)
                                              mapped_datav, segs,
                                              bio, &bio_is_patched,
                                              bio->bi_opf);
-               bio_for_each_segment(bvec, bio, iter)
-                       kunmap(bvec.bv_page);
+               /* Unmap in reverse order */
+               for (--i; i >= 0; i--)
+                       kunmap_local(mapped_datav[i]);
                kfree(mapped_datav);
        } else if (NULL != dev_state && (bio->bi_opf & REQ_PREFLUSH)) {
                if (dev_state->state->print_mask &