Btrfs: relocate file extents in clusters
The extent relocation code copy file extents one by one when
relocating data block group. This is inefficient if file
extents are small. This patch makes the relocation code copy
file extents in clusters. So we can can make better use of
read-ahead.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 48a5042..361ad32 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -121,6 +121,15 @@
int nr;
};
+#define MAX_EXTENTS 128
+
+struct file_extent_cluster {
+ u64 start;
+ u64 end;
+ u64 boundary[MAX_EXTENTS];
+ unsigned int nr;
+};
+
struct reloc_control {
/* block group to relocate */
struct btrfs_block_group_cache *block_group;
@@ -2529,123 +2538,27 @@
}
static noinline_for_stack
-int relocate_inode_pages(struct inode *inode, u64 start, u64 len)
-{
- u64 page_start;
- u64 page_end;
- unsigned long i;
- unsigned long first_index;
- unsigned long last_index;
- unsigned int total_read = 0;
- unsigned int total_dirty = 0;
- struct page *page;
- struct file_ra_state *ra;
- struct btrfs_ordered_extent *ordered;
- struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
- int ret = 0;
-
- ra = kzalloc(sizeof(*ra), GFP_NOFS);
- if (!ra)
- return -ENOMEM;
-
- mutex_lock(&inode->i_mutex);
- first_index = start >> PAGE_CACHE_SHIFT;
- last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
-
- /* make sure the dirty trick played by the caller work */
- while (1) {
- ret = invalidate_inode_pages2_range(inode->i_mapping,
- first_index, last_index);
- if (ret != -EBUSY)
- break;
- schedule_timeout(HZ/10);
- }
- if (ret)
- goto out_unlock;
-
- file_ra_state_init(ra, inode->i_mapping);
-
- for (i = first_index ; i <= last_index; i++) {
- if (total_read % ra->ra_pages == 0) {
- btrfs_force_ra(inode->i_mapping, ra, NULL, i,
- min(last_index, ra->ra_pages + i - 1));
- }
- total_read++;
-again:
- if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
- BUG_ON(1);
- page = grab_cache_page(inode->i_mapping, i);
- if (!page) {
- ret = -ENOMEM;
- goto out_unlock;
- }
- if (!PageUptodate(page)) {
- btrfs_readpage(NULL, page);
- lock_page(page);
- if (!PageUptodate(page)) {
- unlock_page(page);
- page_cache_release(page);
- ret = -EIO;
- goto out_unlock;
- }
- }
- wait_on_page_writeback(page);
-
- page_start = (u64)page->index << PAGE_CACHE_SHIFT;
- page_end = page_start + PAGE_CACHE_SIZE - 1;
- lock_extent(io_tree, page_start, page_end, GFP_NOFS);
-
- ordered = btrfs_lookup_ordered_extent(inode, page_start);
- if (ordered) {
- unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
- unlock_page(page);
- page_cache_release(page);
- btrfs_start_ordered_extent(inode, ordered, 1);
- btrfs_put_ordered_extent(ordered);
- goto again;
- }
- set_page_extent_mapped(page);
-
- if (i == first_index)
- set_extent_bits(io_tree, page_start, page_end,
- EXTENT_BOUNDARY, GFP_NOFS);
- btrfs_set_extent_delalloc(inode, page_start, page_end);
-
- set_page_dirty(page);
- total_dirty++;
-
- unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
- unlock_page(page);
- page_cache_release(page);
- }
-out_unlock:
- mutex_unlock(&inode->i_mutex);
- kfree(ra);
- balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty);
- return ret;
-}
-
-static noinline_for_stack
-int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key)
+int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
+ u64 block_start)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct extent_map *em;
- u64 start = extent_key->objectid - BTRFS_I(inode)->index_cnt;
- u64 end = start + extent_key->offset - 1;
+ int ret = 0;
em = alloc_extent_map(GFP_NOFS);
+ if (!em)
+ return -ENOMEM;
+
em->start = start;
- em->len = extent_key->offset;
- em->block_len = extent_key->offset;
- em->block_start = extent_key->objectid;
+ em->len = end + 1 - start;
+ em->block_len = em->len;
+ em->block_start = block_start;
em->bdev = root->fs_info->fs_devices->latest_bdev;
set_bit(EXTENT_FLAG_PINNED, &em->flags);
- /* setup extent map to cheat btrfs_readpage */
lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
while (1) {
- int ret;
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
write_unlock(&em_tree->lock);
@@ -2656,8 +2569,146 @@
btrfs_drop_extent_cache(inode, start, end, 0);
}
unlock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
+ return ret;
+}
- return relocate_inode_pages(inode, start, extent_key->offset);
+static int relocate_file_extent_cluster(struct inode *inode,
+ struct file_extent_cluster *cluster)
+{
+ u64 page_start;
+ u64 page_end;
+ u64 offset = BTRFS_I(inode)->index_cnt;
+ unsigned long index;
+ unsigned long last_index;
+ unsigned int dirty_page = 0;
+ struct page *page;
+ struct file_ra_state *ra;
+ int nr = 0;
+ int ret = 0;
+
+ if (!cluster->nr)
+ return 0;
+
+ ra = kzalloc(sizeof(*ra), GFP_NOFS);
+ if (!ra)
+ return -ENOMEM;
+
+ index = (cluster->start - offset) >> PAGE_CACHE_SHIFT;
+ last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT;
+
+ mutex_lock(&inode->i_mutex);
+
+ i_size_write(inode, cluster->end + 1 - offset);
+ ret = setup_extent_mapping(inode, cluster->start - offset,
+ cluster->end - offset, cluster->start);
+ if (ret)
+ goto out_unlock;
+
+ file_ra_state_init(ra, inode->i_mapping);
+
+ WARN_ON(cluster->start != cluster->boundary[0]);
+ while (index <= last_index) {
+ page = find_lock_page(inode->i_mapping, index);
+ if (!page) {
+ page_cache_sync_readahead(inode->i_mapping,
+ ra, NULL, index,
+ last_index + 1 - index);
+ page = grab_cache_page(inode->i_mapping, index);
+ if (!page) {
+ ret = -ENOMEM;
+ goto out_unlock;
+ }
+ }
+
+ if (PageReadahead(page)) {
+ page_cache_async_readahead(inode->i_mapping,
+ ra, NULL, page, index,
+ last_index + 1 - index);
+ }
+
+ if (!PageUptodate(page)) {
+ btrfs_readpage(NULL, page);
+ lock_page(page);
+ if (!PageUptodate(page)) {
+ unlock_page(page);
+ page_cache_release(page);
+ ret = -EIO;
+ goto out_unlock;
+ }
+ }
+
+ page_start = (u64)page->index << PAGE_CACHE_SHIFT;
+ page_end = page_start + PAGE_CACHE_SIZE - 1;
+
+ lock_extent(&BTRFS_I(inode)->io_tree,
+ page_start, page_end, GFP_NOFS);
+
+ set_page_extent_mapped(page);
+
+ if (nr < cluster->nr &&
+ page_start + offset == cluster->boundary[nr]) {
+ set_extent_bits(&BTRFS_I(inode)->io_tree,
+ page_start, page_end,
+ EXTENT_BOUNDARY, GFP_NOFS);
+ nr++;
+ }
+ btrfs_set_extent_delalloc(inode, page_start, page_end);
+
+ set_page_dirty(page);
+ dirty_page++;
+
+ unlock_extent(&BTRFS_I(inode)->io_tree,
+ page_start, page_end, GFP_NOFS);
+ unlock_page(page);
+ page_cache_release(page);
+
+ index++;
+ if (nr < cluster->nr &&
+ page_end + 1 + offset == cluster->boundary[nr]) {
+ balance_dirty_pages_ratelimited_nr(inode->i_mapping,
+ dirty_page);
+ dirty_page = 0;
+ }
+ }
+ if (dirty_page) {
+ balance_dirty_pages_ratelimited_nr(inode->i_mapping,
+ dirty_page);
+ }
+ WARN_ON(nr != cluster->nr);
+out_unlock:
+ mutex_unlock(&inode->i_mutex);
+ kfree(ra);
+ return ret;
+}
+
+static noinline_for_stack
+int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
+ struct file_extent_cluster *cluster)
+{
+ int ret;
+
+ if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
+ ret = relocate_file_extent_cluster(inode, cluster);
+ if (ret)
+ return ret;
+ cluster->nr = 0;
+ }
+
+ if (!cluster->nr)
+ cluster->start = extent_key->objectid;
+ else
+ BUG_ON(cluster->nr >= MAX_EXTENTS);
+ cluster->end = extent_key->objectid + extent_key->offset - 1;
+ cluster->boundary[cluster->nr] = extent_key->objectid;
+ cluster->nr++;
+
+ if (cluster->nr >= MAX_EXTENTS) {
+ ret = relocate_file_extent_cluster(inode, cluster);
+ if (ret)
+ return ret;
+ cluster->nr = 0;
+ }
+ return 0;
}
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
@@ -3208,6 +3259,7 @@
{
struct rb_root blocks = RB_ROOT;
struct btrfs_key key;
+ struct file_extent_cluster *cluster;
struct btrfs_trans_handle *trans = NULL;
struct btrfs_path *path;
struct btrfs_extent_item *ei;
@@ -3217,6 +3269,10 @@
int ret;
int err = 0;
+ cluster = kzalloc(sizeof(*cluster), GFP_NOFS);
+ if (!cluster)
+ return -ENOMEM;
+
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
@@ -3310,14 +3366,15 @@
}
nr = trans->blocks_used;
- btrfs_end_transaction_throttle(trans, rc->extent_root);
+ btrfs_end_transaction(trans, rc->extent_root);
trans = NULL;
btrfs_btree_balance_dirty(rc->extent_root, nr);
if (rc->stage == MOVE_DATA_EXTENTS &&
(flags & BTRFS_EXTENT_FLAG_DATA)) {
rc->found_file_extent = 1;
- ret = relocate_data_extent(rc->data_inode, &key);
+ ret = relocate_data_extent(rc->data_inode,
+ &key, cluster);
if (ret < 0) {
err = ret;
break;
@@ -3332,6 +3389,14 @@
btrfs_btree_balance_dirty(rc->extent_root, nr);
}
+ if (!err) {
+ ret = relocate_file_extent_cluster(rc->data_inode, cluster);
+ if (ret < 0)
+ err = ret;
+ }
+
+ kfree(cluster);
+
rc->create_reloc_root = 0;
smp_mb();
@@ -3352,8 +3417,7 @@
}
static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
- struct btrfs_root *root,
- u64 objectid, u64 size)
+ struct btrfs_root *root, u64 objectid)
{
struct btrfs_path *path;
struct btrfs_inode_item *item;
@@ -3372,7 +3436,7 @@
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
btrfs_set_inode_generation(leaf, item, 1);
- btrfs_set_inode_size(leaf, item, size);
+ btrfs_set_inode_size(leaf, item, 0);
btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS);
btrfs_mark_buffer_dirty(leaf);
@@ -3408,12 +3472,7 @@
if (err)
goto out;
- err = __insert_orphan_inode(trans, root, objectid, group->key.offset);
- BUG_ON(err);
-
- err = btrfs_insert_file_extent(trans, root, objectid, 0, 0, 0,
- group->key.offset, 0, group->key.offset,
- 0, 0, 0);
+ err = __insert_orphan_inode(trans, root, objectid);
BUG_ON(err);
key.objectid = objectid;
@@ -3519,10 +3578,10 @@
}
}
- filemap_fdatawrite_range(fs_info->btree_inode->i_mapping,
- rc->block_group->key.objectid,
- rc->block_group->key.objectid +
- rc->block_group->key.offset - 1);
+ filemap_write_and_wait_range(fs_info->btree_inode->i_mapping,
+ rc->block_group->key.objectid,
+ rc->block_group->key.objectid +
+ rc->block_group->key.offset - 1);
WARN_ON(rc->block_group->pinned > 0);
WARN_ON(rc->block_group->reserved > 0);