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/ctree.c b/fs/btrfs/ctree.c
index 2e66786..d243128 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -626,14 +626,6 @@
for (i = start_slot; i < end_slot; i++) {
int close = 1;
- if (!parent->map_token) {
- map_extent_buffer(parent,
- btrfs_node_key_ptr_offset(i),
- sizeof(struct btrfs_key_ptr),
- &parent->map_token, &parent->kaddr,
- &parent->map_start, &parent->map_len,
- KM_USER1);
- }
btrfs_node_key(parent, &disk_key, i);
if (!progress_passed && comp_keys(&disk_key, progress) < 0)
continue;
@@ -656,11 +648,6 @@
last_block = blocknr;
continue;
}
- if (parent->map_token) {
- unmap_extent_buffer(parent, parent->map_token,
- KM_USER1);
- parent->map_token = NULL;
- }
cur = btrfs_find_tree_block(root, blocknr, blocksize);
if (cur)
@@ -701,11 +688,6 @@
btrfs_tree_unlock(cur);
free_extent_buffer(cur);
}
- if (parent->map_token) {
- unmap_extent_buffer(parent, parent->map_token,
- KM_USER1);
- parent->map_token = NULL;
- }
return err;
}
@@ -746,7 +728,6 @@
struct btrfs_disk_key *tmp = NULL;
struct btrfs_disk_key unaligned;
unsigned long offset;
- char *map_token = NULL;
char *kaddr = NULL;
unsigned long map_start = 0;
unsigned long map_len = 0;
@@ -756,18 +737,13 @@
mid = (low + high) / 2;
offset = p + mid * item_size;
- if (!map_token || offset < map_start ||
+ if (!kaddr || offset < map_start ||
(offset + sizeof(struct btrfs_disk_key)) >
map_start + map_len) {
- if (map_token) {
- unmap_extent_buffer(eb, map_token, KM_USER0);
- map_token = NULL;
- }
err = map_private_extent_buffer(eb, offset,
sizeof(struct btrfs_disk_key),
- &map_token, &kaddr,
- &map_start, &map_len, KM_USER0);
+ &kaddr, &map_start, &map_len);
if (!err) {
tmp = (struct btrfs_disk_key *)(kaddr + offset -
@@ -790,14 +766,10 @@
high = mid;
else {
*slot = mid;
- if (map_token)
- unmap_extent_buffer(eb, map_token, KM_USER0);
return 0;
}
}
*slot = low;
- if (map_token)
- unmap_extent_buffer(eb, map_token, KM_USER0);
return 1;
}
@@ -1228,7 +1200,6 @@
u32 nr;
u32 blocksize;
u32 nscan = 0;
- bool map = true;
if (level != 1)
return;
@@ -1250,19 +1221,8 @@
nritems = btrfs_header_nritems(node);
nr = slot;
- if (node->map_token || path->skip_locking)
- map = false;
while (1) {
- if (map && !node->map_token) {
- unsigned long offset = btrfs_node_key_ptr_offset(nr);
- map_private_extent_buffer(node, offset,
- sizeof(struct btrfs_key_ptr),
- &node->map_token,
- &node->kaddr,
- &node->map_start,
- &node->map_len, KM_USER1);
- }
if (direction < 0) {
if (nr == 0)
break;
@@ -1281,11 +1241,6 @@
if ((search <= target && target - search <= 65536) ||
(search > target && search - target <= 65536)) {
gen = btrfs_node_ptr_generation(node, nr);
- if (map && node->map_token) {
- unmap_extent_buffer(node, node->map_token,
- KM_USER1);
- node->map_token = NULL;
- }
readahead_tree_block(root, search, blocksize, gen);
nread += blocksize;
}
@@ -1293,10 +1248,6 @@
if ((nread > 65536 || nscan > 32))
break;
}
- if (map && node->map_token) {
- unmap_extent_buffer(node, node->map_token, KM_USER1);
- node->map_token = NULL;
- }
}
/*
@@ -2253,14 +2204,6 @@
if (path->slots[0] == i)
push_space += data_size;
- if (!left->map_token) {
- map_extent_buffer(left, (unsigned long)item,
- sizeof(struct btrfs_item),
- &left->map_token, &left->kaddr,
- &left->map_start, &left->map_len,
- KM_USER1);
- }
-
this_item_size = btrfs_item_size(left, item);
if (this_item_size + sizeof(*item) + push_space > free_space)
break;
@@ -2271,10 +2214,6 @@
break;
i--;
}
- if (left->map_token) {
- unmap_extent_buffer(left, left->map_token, KM_USER1);
- left->map_token = NULL;
- }
if (push_items == 0)
goto out_unlock;
@@ -2316,21 +2255,10 @@
push_space = BTRFS_LEAF_DATA_SIZE(root);
for (i = 0; i < right_nritems; i++) {
item = btrfs_item_nr(right, i);
- if (!right->map_token) {
- map_extent_buffer(right, (unsigned long)item,
- sizeof(struct btrfs_item),
- &right->map_token, &right->kaddr,
- &right->map_start, &right->map_len,
- KM_USER1);
- }
push_space -= btrfs_item_size(right, item);
btrfs_set_item_offset(right, item, push_space);
}
- if (right->map_token) {
- unmap_extent_buffer(right, right->map_token, KM_USER1);
- right->map_token = NULL;
- }
left_nritems -= push_items;
btrfs_set_header_nritems(left, left_nritems);
@@ -2467,13 +2395,6 @@
for (i = 0; i < nr; i++) {
item = btrfs_item_nr(right, i);
- if (!right->map_token) {
- map_extent_buffer(right, (unsigned long)item,
- sizeof(struct btrfs_item),
- &right->map_token, &right->kaddr,
- &right->map_start, &right->map_len,
- KM_USER1);
- }
if (!empty && push_items > 0) {
if (path->slots[0] < i)
@@ -2496,11 +2417,6 @@
push_space += this_item_size + sizeof(*item);
}
- if (right->map_token) {
- unmap_extent_buffer(right, right->map_token, KM_USER1);
- right->map_token = NULL;
- }
-
if (push_items == 0) {
ret = 1;
goto out;
@@ -2530,23 +2446,12 @@
u32 ioff;
item = btrfs_item_nr(left, i);
- if (!left->map_token) {
- map_extent_buffer(left, (unsigned long)item,
- sizeof(struct btrfs_item),
- &left->map_token, &left->kaddr,
- &left->map_start, &left->map_len,
- KM_USER1);
- }
ioff = btrfs_item_offset(left, item);
btrfs_set_item_offset(left, item,
ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
}
btrfs_set_header_nritems(left, old_left_nritems + push_items);
- if (left->map_token) {
- unmap_extent_buffer(left, left->map_token, KM_USER1);
- left->map_token = NULL;
- }
/* fixup right node */
if (push_items > right_nritems) {
@@ -2574,21 +2479,9 @@
for (i = 0; i < right_nritems; i++) {
item = btrfs_item_nr(right, i);
- if (!right->map_token) {
- map_extent_buffer(right, (unsigned long)item,
- sizeof(struct btrfs_item),
- &right->map_token, &right->kaddr,
- &right->map_start, &right->map_len,
- KM_USER1);
- }
-
push_space = push_space - btrfs_item_size(right, item);
btrfs_set_item_offset(right, item, push_space);
}
- if (right->map_token) {
- unmap_extent_buffer(right, right->map_token, KM_USER1);
- right->map_token = NULL;
- }
btrfs_mark_buffer_dirty(left);
if (right_nritems)
@@ -2729,23 +2622,10 @@
struct btrfs_item *item = btrfs_item_nr(right, i);
u32 ioff;
- if (!right->map_token) {
- map_extent_buffer(right, (unsigned long)item,
- sizeof(struct btrfs_item),
- &right->map_token, &right->kaddr,
- &right->map_start, &right->map_len,
- KM_USER1);
- }
-
ioff = btrfs_item_offset(right, item);
btrfs_set_item_offset(right, item, ioff + rt_data_off);
}
- if (right->map_token) {
- unmap_extent_buffer(right, right->map_token, KM_USER1);
- right->map_token = NULL;
- }
-
btrfs_set_header_nritems(l, mid);
ret = 0;
btrfs_item_key(right, &disk_key, 0);
@@ -3264,23 +3144,10 @@
u32 ioff;
item = btrfs_item_nr(leaf, i);
- if (!leaf->map_token) {
- map_extent_buffer(leaf, (unsigned long)item,
- sizeof(struct btrfs_item),
- &leaf->map_token, &leaf->kaddr,
- &leaf->map_start, &leaf->map_len,
- KM_USER1);
- }
-
ioff = btrfs_item_offset(leaf, item);
btrfs_set_item_offset(leaf, item, ioff + size_diff);
}
- if (leaf->map_token) {
- unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
- leaf->map_token = NULL;
- }
-
/* shift the data */
if (from_end) {
memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
@@ -3377,22 +3244,10 @@
u32 ioff;
item = btrfs_item_nr(leaf, i);
- if (!leaf->map_token) {
- map_extent_buffer(leaf, (unsigned long)item,
- sizeof(struct btrfs_item),
- &leaf->map_token, &leaf->kaddr,
- &leaf->map_start, &leaf->map_len,
- KM_USER1);
- }
ioff = btrfs_item_offset(leaf, item);
btrfs_set_item_offset(leaf, item, ioff - data_size);
}
- if (leaf->map_token) {
- unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
- leaf->map_token = NULL;
- }
-
/* shift the data */
memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
data_end - data_size, btrfs_leaf_data(leaf) +
@@ -3494,27 +3349,13 @@
* item0..itemN ... dataN.offset..dataN.size .. data0.size
*/
/* first correct the data pointers */
- WARN_ON(leaf->map_token);
for (i = slot; i < nritems; i++) {
u32 ioff;
item = btrfs_item_nr(leaf, i);
- if (!leaf->map_token) {
- map_extent_buffer(leaf, (unsigned long)item,
- sizeof(struct btrfs_item),
- &leaf->map_token, &leaf->kaddr,
- &leaf->map_start, &leaf->map_len,
- KM_USER1);
- }
-
ioff = btrfs_item_offset(leaf, item);
btrfs_set_item_offset(leaf, item, ioff - total_data);
}
- if (leaf->map_token) {
- unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
- leaf->map_token = NULL;
- }
-
/* shift the items */
memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
btrfs_item_nr_offset(slot),
@@ -3608,27 +3449,13 @@
* item0..itemN ... dataN.offset..dataN.size .. data0.size
*/
/* first correct the data pointers */
- WARN_ON(leaf->map_token);
for (i = slot; i < nritems; i++) {
u32 ioff;
item = btrfs_item_nr(leaf, i);
- if (!leaf->map_token) {
- map_extent_buffer(leaf, (unsigned long)item,
- sizeof(struct btrfs_item),
- &leaf->map_token, &leaf->kaddr,
- &leaf->map_start, &leaf->map_len,
- KM_USER1);
- }
-
ioff = btrfs_item_offset(leaf, item);
btrfs_set_item_offset(leaf, item, ioff - total_data);
}
- if (leaf->map_token) {
- unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
- leaf->map_token = NULL;
- }
-
/* shift the items */
memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
btrfs_item_nr_offset(slot),
@@ -3840,22 +3667,10 @@
u32 ioff;
item = btrfs_item_nr(leaf, i);
- if (!leaf->map_token) {
- map_extent_buffer(leaf, (unsigned long)item,
- sizeof(struct btrfs_item),
- &leaf->map_token, &leaf->kaddr,
- &leaf->map_start, &leaf->map_len,
- KM_USER1);
- }
ioff = btrfs_item_offset(leaf, item);
btrfs_set_item_offset(leaf, item, ioff + dsize);
}
- if (leaf->map_token) {
- unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
- leaf->map_token = NULL;
- }
-
memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
btrfs_item_nr_offset(slot + nr),
sizeof(struct btrfs_item) *