Btrfs: Support for online FS resize (grow and shrink)
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 1412d55..de0fb07 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -18,6 +18,7 @@
#include <linux/sched.h>
#include <linux/crc32c.h>
+#include <linux/pagemap.h>
#include "hash.h"
#include "ctree.h"
#include "disk-io.h"
@@ -1622,6 +1623,7 @@
int pending_ret;
u64 super_used, root_used;
u64 search_start = 0;
+ u64 new_hint;
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_root *extent_root = info->extent_root;
struct btrfs_extent_item extent_item;
@@ -1629,6 +1631,10 @@
btrfs_set_stack_extent_refs(&extent_item, 1);
+ new_hint = max(hint_byte, 16ULL * 1024 * 1024 * 1024);
+ if (new_hint < btrfs_super_total_bytes(&info->super_copy))
+ hint_byte = new_hint;
+
WARN_ON(num_bytes < root->sectorsize);
ret = find_free_extent(trans, root, num_bytes, empty_size,
search_start, search_end, hint_byte, ins,
@@ -2100,6 +2106,480 @@
return 0;
}
+static int relocate_inode_pages(struct inode *inode, u64 start, u64 len)
+{
+ u64 page_start;
+ u64 page_end;
+ u64 delalloc_start;
+ u64 existing_delalloc;
+ unsigned long last_index;
+ unsigned long first_index;
+ unsigned long i;
+ struct page *page;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+ struct file_ra_state ra;
+
+ mutex_lock(&inode->i_mutex);
+ first_index = start >> PAGE_CACHE_SHIFT;
+ last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
+
+ memset(&ra, 0, sizeof(ra));
+ file_ra_state_init(&ra, inode->i_mapping);
+ btrfs_force_ra(inode->i_mapping, &ra, NULL, first_index, last_index);
+
+ for (i = first_index; i <= last_index; i++) {
+ 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 = (u64)page->index << PAGE_CACHE_SHIFT;
+ page_end = page_start + PAGE_CACHE_SIZE - 1;
+
+ lock_extent(em_tree, page_start, page_end, GFP_NOFS);
+
+ delalloc_start = page_start;
+ existing_delalloc =
+ count_range_bits(&BTRFS_I(inode)->extent_tree,
+ &delalloc_start, page_end,
+ PAGE_CACHE_SIZE, EXTENT_DELALLOC);
+
+ set_extent_delalloc(em_tree, page_start,
+ page_end, GFP_NOFS);
+
+ spin_lock(&root->fs_info->delalloc_lock);
+ root->fs_info->delalloc_bytes += PAGE_CACHE_SIZE -
+ existing_delalloc;
+ spin_unlock(&root->fs_info->delalloc_lock);
+
+ unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
+ set_page_dirty(page);
+ unlock_page(page);
+ page_cache_release(page);
+ }
+
+out_unlock:
+ mutex_unlock(&inode->i_mutex);
+ return 0;
+}
+
+static int relocate_one_reference(struct btrfs_root *extent_root,
+ struct btrfs_path *path,
+ struct btrfs_key *extent_key,
+ u64 ref_root, u64 ref_gen, u64 ref_objectid,
+ u64 ref_offset)
+{
+ struct inode *inode;
+ struct btrfs_root *found_root;
+ struct btrfs_key root_location;
+ int ret;
+
+ root_location.objectid = ref_root;
+ if (ref_gen == 0)
+ root_location.offset = 0;
+ else
+ root_location.offset = (u64)-1;
+ root_location.type = BTRFS_ROOT_ITEM_KEY;
+
+ found_root = btrfs_read_fs_root_no_name(extent_root->fs_info,
+ &root_location);
+ BUG_ON(!found_root);
+
+ if (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
+ mutex_unlock(&extent_root->fs_info->fs_mutex);
+ inode = btrfs_iget_locked(extent_root->fs_info->sb,
+ ref_objectid, found_root);
+ if (inode->i_state & I_NEW) {
+ /* the inode and parent dir are two different roots */
+ BTRFS_I(inode)->root = found_root;
+ BTRFS_I(inode)->location.objectid = ref_objectid;
+ BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
+ BTRFS_I(inode)->location.offset = 0;
+ btrfs_read_locked_inode(inode);
+ unlock_new_inode(inode);
+
+ }
+ /* this can happen if the reference is not against
+ * the latest version of the tree root
+ */
+ if (is_bad_inode(inode)) {
+ mutex_lock(&extent_root->fs_info->fs_mutex);
+ goto out;
+ }
+ relocate_inode_pages(inode, ref_offset, extent_key->offset);
+ /* FIXME, data=ordered will help get rid of this */
+ filemap_fdatawrite(inode->i_mapping);
+ iput(inode);
+ mutex_lock(&extent_root->fs_info->fs_mutex);
+ } else {
+ struct btrfs_trans_handle *trans;
+ struct btrfs_key found_key;
+ struct extent_buffer *eb;
+ int level;
+ int i;
+
+ trans = btrfs_start_transaction(found_root, 1);
+ eb = read_tree_block(found_root, extent_key->objectid,
+ extent_key->offset);
+ level = btrfs_header_level(eb);
+
+ if (level == 0)
+ btrfs_item_key_to_cpu(eb, &found_key, 0);
+ else
+ btrfs_node_key_to_cpu(eb, &found_key, 0);
+
+ free_extent_buffer(eb);
+
+ path->lowest_level = level;
+ path->reada = 0;
+ ret = btrfs_search_slot(trans, found_root, &found_key, path,
+ 0, 1);
+ path->lowest_level = 0;
+ for (i = level; i < BTRFS_MAX_LEVEL; i++) {
+ if (!path->nodes[i])
+ break;
+ free_extent_buffer(path->nodes[i]);
+ path->nodes[i] = NULL;
+ }
+ btrfs_release_path(found_root, path);
+ btrfs_end_transaction(trans, found_root);
+ }
+
+out:
+ return 0;
+}
+
+static int relocate_one_extent(struct btrfs_root *extent_root,
+ struct btrfs_path *path,
+ struct btrfs_key *extent_key)
+{
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ struct btrfs_extent_ref *ref;
+ struct extent_buffer *leaf;
+ u64 ref_root;
+ u64 ref_gen;
+ u64 ref_objectid;
+ u64 ref_offset;
+ u32 nritems;
+ u32 item_size;
+ int ret = 0;
+
+ key.objectid = extent_key->objectid;
+ key.type = BTRFS_EXTENT_REF_KEY;
+ key.offset = 0;
+
+ while(1) {
+ ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
+
+ BUG_ON(ret == 0);
+
+ if (ret < 0)
+ goto out;
+
+ ret = 0;
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ if (path->slots[0] == nritems)
+ goto out;
+
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ if (found_key.objectid != extent_key->objectid)
+ break;
+
+ if (found_key.type != BTRFS_EXTENT_REF_KEY)
+ break;
+
+ key.offset = found_key.offset + 1;
+ item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+
+ ref = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_ref);
+ ref_root = btrfs_ref_root(leaf, ref);
+ ref_gen = btrfs_ref_generation(leaf, ref);
+ ref_objectid = btrfs_ref_objectid(leaf, ref);
+ ref_offset = btrfs_ref_offset(leaf, ref);
+ btrfs_release_path(extent_root, path);
+
+ ret = relocate_one_reference(extent_root, path,
+ extent_key, ref_root, ref_gen,
+ ref_objectid, ref_offset);
+ if (ret)
+ goto out;
+ }
+ ret = 0;
+out:
+ btrfs_release_path(extent_root, path);
+ return ret;
+}
+
+static int find_overlapping_extent(struct btrfs_root *root,
+ struct btrfs_path *path, u64 new_size)
+{
+ struct btrfs_key found_key;
+ struct extent_buffer *leaf;
+ int ret;
+
+ while(1) {
+ if (path->slots[0] == 0) {
+ ret = btrfs_prev_leaf(root, path);
+ if (ret == 1) {
+ return 1;
+ }
+ if (ret < 0)
+ return ret;
+ } else {
+ path->slots[0]--;
+ }
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ if (found_key.type == BTRFS_EXTENT_ITEM_KEY) {
+ if (found_key.objectid + found_key.offset > new_size)
+ return 0;
+ else
+ return 1;
+ }
+ }
+ return 1;
+}
+
+int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 new_size)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *tree_root = root->fs_info->tree_root;
+ struct btrfs_path *path;
+ u64 cur_byte;
+ u64 total_found;
+ u64 ptr;
+ struct btrfs_fs_info *info = root->fs_info;
+ struct extent_map_tree *block_group_cache;
+ struct btrfs_key key;
+ struct btrfs_key found_key = { 0, 0, 0 };
+ struct extent_buffer *leaf;
+ u32 nritems;
+ int ret;
+ int slot;
+
+ btrfs_set_super_total_bytes(&info->super_copy, new_size);
+ block_group_cache = &info->block_group_cache;
+ path = btrfs_alloc_path();
+ root = root->fs_info->extent_root;
+
+again:
+ total_found = 0;
+ key.objectid = new_size;
+ cur_byte = key.objectid;
+ key.offset = 0;
+ key.type = 0;
+ while(1) {
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+next:
+ leaf = path->nodes[0];
+ if (key.objectid == new_size - 1) {
+ ret = find_overlapping_extent(root, path, new_size);
+ if (ret != 0) {
+ btrfs_release_path(root, path);
+ ret = btrfs_search_slot(NULL, root, &key,
+ path, 0, 0);
+ if (ret < 0)
+ goto out;
+ }
+ }
+ nritems = btrfs_header_nritems(leaf);
+ ret = 0;
+ slot = path->slots[0];
+ if (slot < nritems)
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+ if (slot == nritems ||
+ btrfs_key_type(&found_key) != BTRFS_EXTENT_ITEM_KEY) {
+ path->slots[0]++;
+ if (path->slots[0] >= nritems) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ goto out;
+ if (ret == 1) {
+ ret = 0;
+ break;
+ }
+ }
+ goto next;
+ }
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+ if (found_key.objectid + found_key.offset <= cur_byte)
+ continue;
+ total_found++;
+ cur_byte = found_key.objectid + found_key.offset;
+ key.objectid = cur_byte;
+ btrfs_release_path(root, path);
+ ret = relocate_one_extent(root, path, &found_key);
+ }
+
+ btrfs_release_path(root, path);
+
+ if (total_found > 0) {
+ trans = btrfs_start_transaction(tree_root, 1);
+ btrfs_commit_transaction(trans, tree_root);
+
+ mutex_unlock(&root->fs_info->fs_mutex);
+ btrfs_clean_old_snapshots(tree_root);
+ mutex_lock(&root->fs_info->fs_mutex);
+
+ trans = btrfs_start_transaction(tree_root, 1);
+ btrfs_commit_transaction(trans, tree_root);
+ goto again;
+ }
+
+ trans = btrfs_start_transaction(root, 1);
+ key.objectid = new_size;
+ key.offset = 0;
+ key.type = 0;
+ while(1) {
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret < 0)
+ goto out;
+bg_next:
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
+ ret = 0;
+ slot = path->slots[0];
+ if (slot < nritems)
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+ if (slot == nritems ||
+ btrfs_key_type(&found_key) != BTRFS_BLOCK_GROUP_ITEM_KEY) {
+ if (slot < nritems) {
+ printk("shrinker found key %Lu %u %Lu\n",
+ found_key.objectid, found_key.type,
+ found_key.offset);
+ path->slots[0]++;
+ }
+ if (path->slots[0] >= nritems) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ break;
+ if (ret == 1) {
+ ret = 0;
+ break;
+ }
+ }
+ goto bg_next;
+ }
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+ ret = get_state_private(&info->block_group_cache,
+ found_key.objectid, &ptr);
+ if (!ret)
+ kfree((void *)(unsigned long)ptr);
+
+ clear_extent_bits(&info->block_group_cache, found_key.objectid,
+ found_key.objectid + found_key.offset - 1,
+ (unsigned int)-1, GFP_NOFS);
+
+ key.objectid = found_key.objectid + 1;
+ btrfs_del_item(trans, root, path);
+ btrfs_release_path(root, path);
+ }
+ clear_extent_dirty(&info->free_space_cache, new_size, (u64)-1,
+ GFP_NOFS);
+ btrfs_commit_transaction(trans, root);
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_grow_extent_tree(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 new_size)
+{
+ struct btrfs_path *path;
+ u64 nr = 0;
+ u64 cur_byte;
+ u64 old_size;
+ struct btrfs_block_group_cache *cache;
+ struct btrfs_block_group_item *item;
+ struct btrfs_fs_info *info = root->fs_info;
+ struct extent_map_tree *block_group_cache;
+ struct btrfs_key key;
+ struct extent_buffer *leaf;
+ int ret;
+ int bit;
+
+ old_size = btrfs_super_total_bytes(&info->super_copy);
+ block_group_cache = &info->block_group_cache;
+
+ root = info->extent_root;
+
+ cache = btrfs_lookup_block_group(root->fs_info, old_size - 1);
+
+ cur_byte = cache->key.objectid + cache->key.offset;
+ if (cur_byte >= new_size)
+ goto set_size;
+
+ key.offset = BTRFS_BLOCK_GROUP_SIZE;
+ btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ while(cur_byte < new_size) {
+ key.objectid = cur_byte;
+ ret = btrfs_insert_empty_item(trans, root, path, &key,
+ sizeof(struct btrfs_block_group_item));
+ BUG_ON(ret);
+ leaf = path->nodes[0];
+ item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_block_group_item);
+
+ btrfs_set_disk_block_group_used(leaf, item, 0);
+ if (nr % 3) {
+ btrfs_set_disk_block_group_flags(leaf, item,
+ BTRFS_BLOCK_GROUP_DATA);
+ } else {
+ btrfs_set_disk_block_group_flags(leaf, item, 0);
+ }
+ nr++;
+
+ cache = kmalloc(sizeof(*cache), GFP_NOFS);
+ BUG_ON(!cache);
+
+ read_extent_buffer(leaf, &cache->item, (unsigned long)item,
+ sizeof(cache->item));
+
+ memcpy(&cache->key, &key, sizeof(key));
+ cache->cached = 0;
+ cache->pinned = 0;
+ cur_byte = key.objectid + key.offset;
+ btrfs_release_path(root, path);
+
+ if (cache->item.flags & BTRFS_BLOCK_GROUP_DATA) {
+ bit = BLOCK_GROUP_DATA;
+ cache->data = BTRFS_BLOCK_GROUP_DATA;
+ } else {
+ bit = BLOCK_GROUP_METADATA;
+ cache->data = 0;
+ }
+
+ /* use EXTENT_LOCKED to prevent merging */
+ set_extent_bits(block_group_cache, key.objectid,
+ key.objectid + key.offset - 1,
+ bit | EXTENT_LOCKED, GFP_NOFS);
+ set_state_private(block_group_cache, key.objectid,
+ (unsigned long)cache);
+ }
+ btrfs_free_path(path);
+set_size:
+ btrfs_set_super_total_bytes(&info->super_copy, new_size);
+ return 0;
+}
+
int btrfs_read_block_groups(struct btrfs_root *root)
{
struct btrfs_path *path;