Btrfs: Do metadata checksums for reads via a workqueue

Before, metadata checksumming was done by the callers of read_tree_block,
which would set EXTENT_CSUM bits in the extent tree to show that a given
range of pages was already checksummed and didn't need to be verified
again.

But, those bits could go away via try_to_releasepage, and the end
result was bogus checksum failures on pages that never left the cache.

The new code validates checksums when the page is read.  It is a little
tricky because metadata blocks can span pages and a single read may
end up going via multiple bios.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason
2008-04-09 16:28:12 -04:00
parent 728131d8e4
commit ce9adaa5a7
7 changed files with 310 additions and 67 deletions

View File

@ -1898,10 +1898,6 @@ struct extent_buffer *__btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
buf->start + buf->len - 1, GFP_NOFS);
set_extent_bits(&BTRFS_I(root->fs_info->btree_inode)->io_tree,
buf->start, buf->start + buf->len - 1,
EXTENT_CSUM, GFP_NOFS);
buf->flags |= EXTENT_CSUM;
if (!btrfs_test_opt(root, SSD))
btrfs_set_buffer_defrag(buf);
trans->blocks_used++;