Commit 9a002d53 authored by Ira Weiny's avatar Ira Weiny Committed by David Sterba
Browse files

btrfs: integrity-checker: convert block context kmap's to kmap_local_page 



btrfsic_read_block() (which calls kmap()) and
btrfsic_release_block_ctx() (which calls kunmap()) are always called
within a single thread of execution.

Therefore the mappings created within these calls can be a thread local
mapping.

Convert the kmap() of bloc_ctx->pagev to kmap_local_page().  Luckily the
unmap loops backwards through the array pointer so no adjustment needs
to be made to the unmapping order.

Signed-off-by: default avatarIra Weiny <ira.weiny@intel.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 3e037efd

fs/btrfs/check-integrity.c

+3 −2
Original line number Diff line number Diff line
@@ -1555,10 +1555,11 @@ static void btrfsic_release_block_ctx(struct btrfsic_block_data_ctx *block_ctx) 
		BUG_ON(!block_ctx->pagev);

		num_pages = (block_ctx->len + (u64)PAGE_SIZE - 1) >>

			    PAGE_SHIFT;

		/* Pages must be unmapped in reverse order */

		while (num_pages > 0) {

			num_pages--;

			if (block_ctx->datav[num_pages]) {

				kunmap(block_ctx->pagev[num_pages]);

				kunmap_local(block_ctx->datav[num_pages]);

				block_ctx->datav[num_pages] = NULL;

			}

			if (block_ctx->pagev[num_pages]) {
@@ -1637,7 +1638,7 @@ static int btrfsic_read_block(struct btrfsic_state *state, 
		i = j;

	}

	for (i = 0; i < num_pages; i++)

		block_ctx->datav[i] = kmap(block_ctx->pagev[i]);

		block_ctx->datav[i] = kmap_local_page(block_ctx->pagev[i]);



	return block_ctx->len;

}