Btrfs: stop using highmem for extent_buffers
The extent_buffers have a very complex interface where
we use HIGHMEM for metadata and try to cache a kmap mapping
to access the memory.
The next commit adds reader/writer locks, and concurrent use
of this kmap cache would make it even more complex.
This commit drops the ability to use HIGHMEM with extent buffers,
and rips out all of the related code.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 234a084..97f22ff 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -217,7 +217,6 @@
unsigned long len;
unsigned long cur_len;
unsigned long offset = BTRFS_CSUM_SIZE;
- char *map_token = NULL;
char *kaddr;
unsigned long map_start;
unsigned long map_len;
@@ -228,8 +227,7 @@
len = buf->len - offset;
while (len > 0) {
err = map_private_extent_buffer(buf, offset, 32,
- &map_token, &kaddr,
- &map_start, &map_len, KM_USER0);
+ &kaddr, &map_start, &map_len);
if (err)
return 1;
cur_len = min(len, map_len - (offset - map_start));
@@ -237,7 +235,6 @@
crc, cur_len);
len -= cur_len;
offset += cur_len;
- unmap_extent_buffer(buf, map_token, KM_USER0);
}
if (csum_size > sizeof(inline_result)) {
result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
@@ -1603,7 +1600,7 @@
goto fail_bdi;
}
- fs_info->btree_inode->i_mapping->flags &= ~__GFP_FS;
+ mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
INIT_LIST_HEAD(&fs_info->trans_list);
