Add support for defragging files via btrfsctl -d. Avoid OOM on extent tree
defrag.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 64710fa..6b3e440 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1904,6 +1904,70 @@
return ret;
}
+static unsigned long force_ra(struct address_space *mapping,
+ struct file_ra_state *ra, struct file *file,
+ pgoff_t offset, pgoff_t last_index)
+{
+ pgoff_t req_size;
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
+ req_size = last_index - offset + 1;
+ offset = page_cache_readahead(mapping, ra, file, offset, req_size);
+ return offset;
+#else
+ req_size = min(last_index - offset + 1, (pgoff_t)128);
+ page_cache_sync_readahead(mapping, ra, file, offset, req_size);
+ return offset + req_size;
+#endif
+}
+
+int btrfs_defrag_file(struct file *file) {
+ struct inode *inode = file->f_path.dentry->d_inode;
+ struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+ struct page *page;
+ unsigned long last_index;
+ unsigned long ra_index = 0;
+ u64 page_start;
+ u64 page_end;
+ unsigned long i;
+
+ mutex_lock(&inode->i_mutex);
+ last_index = inode->i_size >> PAGE_CACHE_SHIFT;
+ for (i = 0; i <= last_index; i++) {
+ if (i == ra_index) {
+ ra_index = force_ra(inode->i_mapping, &file->f_ra,
+ file, ra_index, last_index);
+ }
+ page = grab_cache_page(inode->i_mapping, i);
+ if (!page)
+ goto out_unlock;
+ if (!PageUptodate(page)) {
+ btrfs_readpage(NULL, page);
+ lock_page(page);
+ if (!PageUptodate(page)) {
+ unlock_page(page);
+ page_cache_release(page);
+ goto out_unlock;
+ }
+ }
+ page_start = page->index << PAGE_CACHE_SHIFT;
+ page_end = page_start + PAGE_CACHE_SIZE - 1;
+
+ lock_extent(em_tree, page_start, page_end, GFP_NOFS);
+ set_extent_delalloc(em_tree, page_start,
+ page_end, GFP_NOFS);
+ unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
+ set_page_dirty(page);
+ unlock_page(page);
+ page_cache_release(page);
+ balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
+ }
+
+out_unlock:
+ mutex_unlock(&inode->i_mutex);
+ return 0;
+}
+
int btrfs_ioctl(struct inode *inode, struct file *filp, unsigned int
cmd, unsigned long arg)
{
@@ -1948,10 +2012,14 @@
break;
case BTRFS_IOC_DEFRAG:
- mutex_lock(&root->fs_info->fs_mutex);
- btrfs_defrag_root(root, 0);
- btrfs_defrag_root(root->fs_info->extent_root, 0);
- mutex_unlock(&root->fs_info->fs_mutex);
+ if (S_ISDIR(inode->i_mode)) {
+ mutex_lock(&root->fs_info->fs_mutex);
+ btrfs_defrag_root(root, 0);
+ btrfs_defrag_root(root->fs_info->extent_root, 0);
+ mutex_unlock(&root->fs_info->fs_mutex);
+ } else if (S_ISREG(inode->i_mode)) {
+ btrfs_defrag_file(filp);
+ }
ret = 0;
break;
default:
@@ -2018,7 +2086,7 @@
kmem_cache_destroy(btrfs_path_cachep);
}
-static struct kmem_cache *cache_create(const char *name, size_t size,
+struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
unsigned long extra_flags,
void (*ctor)(void *, struct kmem_cache *,
unsigned long))
@@ -2033,27 +2101,28 @@
int btrfs_init_cachep(void)
{
- btrfs_inode_cachep = cache_create("btrfs_inode_cache",
+ btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache",
sizeof(struct btrfs_inode),
0, init_once);
if (!btrfs_inode_cachep)
goto fail;
- btrfs_trans_handle_cachep = cache_create("btrfs_trans_handle_cache",
- sizeof(struct btrfs_trans_handle),
- 0, NULL);
+ btrfs_trans_handle_cachep =
+ btrfs_cache_create("btrfs_trans_handle_cache",
+ sizeof(struct btrfs_trans_handle),
+ 0, NULL);
if (!btrfs_trans_handle_cachep)
goto fail;
- btrfs_transaction_cachep = cache_create("btrfs_transaction_cache",
+ btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache",
sizeof(struct btrfs_transaction),
0, NULL);
if (!btrfs_transaction_cachep)
goto fail;
- btrfs_path_cachep = cache_create("btrfs_path_cache",
+ btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache",
sizeof(struct btrfs_transaction),
0, NULL);
if (!btrfs_path_cachep)
goto fail;
- btrfs_bit_radix_cachep = cache_create("btrfs_radix", 256,
+ btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256,
SLAB_DESTROY_BY_RCU, NULL);
if (!btrfs_bit_radix_cachep)
goto fail;
