Btrfs: Split the extent_map code into two parts
There is now extent_map for mapping offsets in the file to disk and
extent_io for state tracking, IO submission and extent_bufers.
The new extent_map code shifts from [start,end] pairs to [start,len], and
pushes the locking out into the caller. This allows a few performance
optimizations and is easier to use.
A number of extent_map usage bugs were fixed, mostly with failing
to remove extent_map entries when changing the file.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 5d1f9bc..4c4ebea 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -43,14 +43,14 @@
}
#endif
-static struct extent_map_ops btree_extent_map_ops;
+static struct extent_io_ops btree_extent_io_ops;
struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
u64 bytenr, u32 blocksize)
{
struct inode *btree_inode = root->fs_info->btree_inode;
struct extent_buffer *eb;
- eb = find_extent_buffer(&BTRFS_I(btree_inode)->extent_tree,
+ eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
bytenr, blocksize, GFP_NOFS);
return eb;
}
@@ -61,13 +61,13 @@
struct inode *btree_inode = root->fs_info->btree_inode;
struct extent_buffer *eb;
- eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->extent_tree,
+ eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
bytenr, blocksize, NULL, GFP_NOFS);
return eb;
}
struct extent_map *btree_get_extent(struct inode *inode, struct page *page,
- size_t page_offset, u64 start, u64 end,
+ size_t page_offset, u64 start, u64 len,
int create)
{
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
@@ -75,7 +75,9 @@
int ret;
again:
- em = lookup_extent_mapping(em_tree, start, end);
+ spin_lock(&em_tree->lock);
+ em = lookup_extent_mapping(em_tree, start, len);
+ spin_unlock(&em_tree->lock);
if (em) {
goto out;
}
@@ -85,11 +87,14 @@
goto out;
}
em->start = 0;
- em->end = (i_size_read(inode) & ~((u64)PAGE_CACHE_SIZE -1)) - 1;
+ em->len = i_size_read(inode);
em->block_start = 0;
- em->block_end = em->end;
em->bdev = inode->i_sb->s_bdev;
+
+ spin_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
+ spin_unlock(&em_tree->lock);
+
if (ret == -EEXIST) {
free_extent_map(em);
em = NULL;
@@ -175,13 +180,13 @@
int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
{
- struct extent_map_tree *tree;
+ struct extent_io_tree *tree;
u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
u64 found_start;
int found_level;
unsigned long len;
struct extent_buffer *eb;
- tree = &BTRFS_I(page->mapping->host)->extent_tree;
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
if (page->private == EXTENT_PAGE_PRIVATE)
goto out;
@@ -230,16 +235,16 @@
static int btree_writepage(struct page *page, struct writeback_control *wbc)
{
- struct extent_map_tree *tree;
- tree = &BTRFS_I(page->mapping->host)->extent_tree;
+ struct extent_io_tree *tree;
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
return extent_write_full_page(tree, page, btree_get_extent, wbc);
}
static int btree_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
- struct extent_map_tree *tree;
- tree = &BTRFS_I(mapping->host)->extent_tree;
+ struct extent_io_tree *tree;
+ tree = &BTRFS_I(mapping->host)->io_tree;
if (wbc->sync_mode == WB_SYNC_NONE) {
u64 num_dirty;
u64 start = 0;
@@ -264,18 +269,20 @@
int btree_readpage(struct file *file, struct page *page)
{
- struct extent_map_tree *tree;
- tree = &BTRFS_I(page->mapping->host)->extent_tree;
+ struct extent_io_tree *tree;
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
return extent_read_full_page(tree, page, btree_get_extent);
}
static int btree_releasepage(struct page *page, gfp_t unused_gfp_flags)
{
- struct extent_map_tree *tree;
+ struct extent_io_tree *tree;
+ struct extent_map_tree *map;
int ret;
- tree = &BTRFS_I(page->mapping->host)->extent_tree;
- ret = try_release_extent_mapping(tree, page);
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
+ map = &BTRFS_I(page->mapping->host)->extent_tree;
+ ret = try_release_extent_mapping(map, tree, page);
if (ret == 1) {
ClearPagePrivate(page);
set_page_private(page, 0);
@@ -286,8 +293,8 @@
static void btree_invalidatepage(struct page *page, unsigned long offset)
{
- struct extent_map_tree *tree;
- tree = &BTRFS_I(page->mapping->host)->extent_tree;
+ struct extent_io_tree *tree;
+ tree = &BTRFS_I(page->mapping->host)->io_tree;
extent_invalidatepage(tree, page, offset);
btree_releasepage(page, GFP_NOFS);
}
@@ -331,7 +338,7 @@
buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
if (!buf)
return 0;
- read_extent_buffer_pages(&BTRFS_I(btree_inode)->extent_tree,
+ read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
buf, 0, 0);
free_extent_buffer(buf);
return ret;
@@ -342,40 +349,39 @@
{
struct extent_buffer *buf = NULL;
struct inode *btree_inode = root->fs_info->btree_inode;
- struct extent_map_tree *extent_tree;
+ struct extent_io_tree *io_tree;
u64 end;
int ret;
- extent_tree = &BTRFS_I(btree_inode)->extent_tree;
+ io_tree = &BTRFS_I(btree_inode)->io_tree;
buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
if (!buf)
return NULL;
- read_extent_buffer_pages(&BTRFS_I(btree_inode)->extent_tree,
- buf, 0, 1);
+ read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree, buf, 0, 1);
if (buf->flags & EXTENT_CSUM)
return buf;
end = buf->start + PAGE_CACHE_SIZE - 1;
- if (test_range_bit(extent_tree, buf->start, end, EXTENT_CSUM, 1)) {
+ if (test_range_bit(io_tree, buf->start, end, EXTENT_CSUM, 1)) {
buf->flags |= EXTENT_CSUM;
return buf;
}
- lock_extent(extent_tree, buf->start, end, GFP_NOFS);
+ lock_extent(io_tree, buf->start, end, GFP_NOFS);
- if (test_range_bit(extent_tree, buf->start, end, EXTENT_CSUM, 1)) {
+ if (test_range_bit(io_tree, buf->start, end, EXTENT_CSUM, 1)) {
buf->flags |= EXTENT_CSUM;
goto out_unlock;
}
ret = csum_tree_block(root, buf, 1);
- set_extent_bits(extent_tree, buf->start, end, EXTENT_CSUM, GFP_NOFS);
+ set_extent_bits(io_tree, buf->start, end, EXTENT_CSUM, GFP_NOFS);
buf->flags |= EXTENT_CSUM;
out_unlock:
- unlock_extent(extent_tree, buf->start, end, GFP_NOFS);
+ unlock_extent(io_tree, buf->start, end, GFP_NOFS);
return buf;
}
@@ -385,7 +391,7 @@
struct inode *btree_inode = root->fs_info->btree_inode;
if (btrfs_header_generation(buf) ==
root->fs_info->running_transaction->transid)
- clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->extent_tree,
+ clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
buf);
return 0;
}
@@ -394,7 +400,7 @@
struct extent_buffer *buf)
{
struct inode *btree_inode = root->fs_info->btree_inode;
- wait_on_extent_buffer_writeback(&BTRFS_I(btree_inode)->extent_tree,
+ wait_on_extent_buffer_writeback(&BTRFS_I(btree_inode)->io_tree,
buf);
return 0;
}
@@ -659,20 +665,23 @@
fs_info->btree_inode->i_nlink = 1;
fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
- extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
+ extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
fs_info->btree_inode->i_mapping,
GFP_NOFS);
- BTRFS_I(fs_info->btree_inode)->extent_tree.ops = &btree_extent_map_ops;
+ extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
+ GFP_NOFS);
- extent_map_tree_init(&fs_info->free_space_cache,
+ BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
+
+ extent_io_tree_init(&fs_info->free_space_cache,
fs_info->btree_inode->i_mapping, GFP_NOFS);
- extent_map_tree_init(&fs_info->block_group_cache,
+ extent_io_tree_init(&fs_info->block_group_cache,
fs_info->btree_inode->i_mapping, GFP_NOFS);
- extent_map_tree_init(&fs_info->pinned_extents,
+ extent_io_tree_init(&fs_info->pinned_extents,
fs_info->btree_inode->i_mapping, GFP_NOFS);
- extent_map_tree_init(&fs_info->pending_del,
+ extent_io_tree_init(&fs_info->pending_del,
fs_info->btree_inode->i_mapping, GFP_NOFS);
- extent_map_tree_init(&fs_info->extent_ins,
+ extent_io_tree_init(&fs_info->extent_ins,
fs_info->btree_inode->i_mapping, GFP_NOFS);
fs_info->do_barriers = 1;
fs_info->closing = 0;
@@ -787,7 +796,7 @@
if (!btrfs_test_opt(root, NOBARRIER))
blkdev_issue_flush(sb->s_bdev, NULL);
- set_extent_buffer_dirty(&BTRFS_I(btree_inode)->extent_tree, super);
+ set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, super);
ret = sync_page_range_nolock(btree_inode, btree_inode->i_mapping,
super->start, super->len);
if (!btrfs_test_opt(root, NOBARRIER))
@@ -864,12 +873,12 @@
filemap_write_and_wait(fs_info->btree_inode->i_mapping);
- extent_map_tree_empty_lru(&fs_info->free_space_cache);
- extent_map_tree_empty_lru(&fs_info->block_group_cache);
- extent_map_tree_empty_lru(&fs_info->pinned_extents);
- extent_map_tree_empty_lru(&fs_info->pending_del);
- extent_map_tree_empty_lru(&fs_info->extent_ins);
- extent_map_tree_empty_lru(&BTRFS_I(fs_info->btree_inode)->extent_tree);
+ extent_io_tree_empty_lru(&fs_info->free_space_cache);
+ extent_io_tree_empty_lru(&fs_info->block_group_cache);
+ extent_io_tree_empty_lru(&fs_info->pinned_extents);
+ extent_io_tree_empty_lru(&fs_info->pending_del);
+ extent_io_tree_empty_lru(&fs_info->extent_ins);
+ extent_io_tree_empty_lru(&BTRFS_I(fs_info->btree_inode)->io_tree);
truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
@@ -892,13 +901,13 @@
int btrfs_buffer_uptodate(struct extent_buffer *buf)
{
struct inode *btree_inode = buf->first_page->mapping->host;
- return extent_buffer_uptodate(&BTRFS_I(btree_inode)->extent_tree, buf);
+ return extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
}
int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
{
struct inode *btree_inode = buf->first_page->mapping->host;
- return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->extent_tree,
+ return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
buf);
}
@@ -914,7 +923,7 @@
transid, root->fs_info->generation);
WARN_ON(1);
}
- set_extent_buffer_dirty(&BTRFS_I(btree_inode)->extent_tree, buf);
+ set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf);
}
void btrfs_throttle(struct btrfs_root *root)
@@ -941,7 +950,7 @@
{
struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
struct inode *btree_inode = root->fs_info->btree_inode;
- set_extent_bits(&BTRFS_I(btree_inode)->extent_tree, buf->start,
+ set_extent_bits(&BTRFS_I(btree_inode)->io_tree, buf->start,
buf->start + buf->len - 1, EXTENT_DEFRAG, GFP_NOFS);
}
@@ -949,7 +958,7 @@
{
struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
struct inode *btree_inode = root->fs_info->btree_inode;
- set_extent_bits(&BTRFS_I(btree_inode)->extent_tree, buf->start,
+ set_extent_bits(&BTRFS_I(btree_inode)->io_tree, buf->start,
buf->start + buf->len - 1, EXTENT_DEFRAG_DONE,
GFP_NOFS);
}
@@ -958,7 +967,7 @@
{
struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
struct inode *btree_inode = root->fs_info->btree_inode;
- return test_range_bit(&BTRFS_I(btree_inode)->extent_tree,
+ return test_range_bit(&BTRFS_I(btree_inode)->io_tree,
buf->start, buf->start + buf->len - 1, EXTENT_DEFRAG, 0);
}
@@ -966,7 +975,7 @@
{
struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
struct inode *btree_inode = root->fs_info->btree_inode;
- return test_range_bit(&BTRFS_I(btree_inode)->extent_tree,
+ return test_range_bit(&BTRFS_I(btree_inode)->io_tree,
buf->start, buf->start + buf->len - 1,
EXTENT_DEFRAG_DONE, 0);
}
@@ -975,7 +984,7 @@
{
struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
struct inode *btree_inode = root->fs_info->btree_inode;
- return clear_extent_bits(&BTRFS_I(btree_inode)->extent_tree,
+ return clear_extent_bits(&BTRFS_I(btree_inode)->io_tree,
buf->start, buf->start + buf->len - 1,
EXTENT_DEFRAG_DONE, GFP_NOFS);
}
@@ -984,7 +993,7 @@
{
struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
struct inode *btree_inode = root->fs_info->btree_inode;
- return clear_extent_bits(&BTRFS_I(btree_inode)->extent_tree,
+ return clear_extent_bits(&BTRFS_I(btree_inode)->io_tree,
buf->start, buf->start + buf->len - 1,
EXTENT_DEFRAG, GFP_NOFS);
}
@@ -993,10 +1002,10 @@
{
struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
struct inode *btree_inode = root->fs_info->btree_inode;
- return read_extent_buffer_pages(&BTRFS_I(btree_inode)->extent_tree,
+ return read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
buf, 0, 1);
}
-static struct extent_map_ops btree_extent_map_ops = {
+static struct extent_io_ops btree_extent_io_ops = {
.writepage_io_hook = btree_writepage_io_hook,
};