btrfs-progs: docs: update dev stats help and manual page

[platform/upstream/btrfs-progs.git] / free-space-cache.c

diff --git a/free-space-cache.c b/free-space-cache.c
index 357d69e..286b185 100644 (file)
--- a/free-space-cache.c
+++ b/free-space-cache.c
@@ -25,6 +25,7 @@
 #include "crc32c.h"
 #include "bitops.h"
 #include "internal.h"
+#include "utils.h"
 
 /*
  * Kernel always uses PAGE_CACHE_SIZE for sectorsize, but we don't have
@@ -210,7 +211,7 @@ static int io_ctl_check_crc(struct io_ctl *io_ctl, int index)
 
        io_ctl_map_page(io_ctl, 0);
        crc = crc32c(crc, io_ctl->orig + offset, io_ctl->root->sectorsize - offset);
-       btrfs_csum_final(crc, (char *)&crc);
+       btrfs_csum_final(crc, (u8 *)&crc);
        if (val != crc) {
                printk("btrfs: csum mismatch on free space cache\n");
                io_ctl_unmap_page(io_ctl);
@@ -877,3 +878,129 @@ next:
                prev = e;
        }
 }
+
+int btrfs_clear_free_space_cache(struct btrfs_fs_info *fs_info,
+                                struct btrfs_block_group_cache *bg)
+{
+       struct btrfs_trans_handle *trans;
+       struct btrfs_root *tree_root = fs_info->tree_root;
+       struct btrfs_path path;
+       struct btrfs_key key;
+       struct btrfs_disk_key location;
+       struct btrfs_free_space_header *sc_header;
+       struct extent_buffer *node;
+       u64 ino;
+       int slot;
+       int ret;
+
+       trans = btrfs_start_transaction(tree_root, 1);
+       if (IS_ERR(trans))
+               return PTR_ERR(trans);
+
+       btrfs_init_path(&path);
+
+       key.objectid = BTRFS_FREE_SPACE_OBJECTID;
+       key.type = 0;
+       key.offset = bg->key.objectid;
+
+       ret = btrfs_search_slot(trans, tree_root, &key, &path, -1, 1);
+       if (ret > 0) {
+               ret = 0;
+               goto out;
+       }
+       if (ret < 0)
+               goto out;
+
+       node = path.nodes[0];
+       slot = path.slots[0];
+       sc_header = btrfs_item_ptr(node, slot, struct btrfs_free_space_header);
+       btrfs_free_space_key(node, sc_header, &location);
+       ino = location.objectid;
+
+       /* Delete the free space header, as we have the ino to continue */
+       ret = btrfs_del_item(trans, tree_root, &path);
+       if (ret < 0) {
+               error("failed to remove free space header for block group %llu: %d",
+                     bg->key.objectid, ret);
+               goto out;
+       }
+       btrfs_release_path(&path);
+
+       /* Iterate from the end of the free space cache inode */
+       key.objectid = ino;
+       key.type = BTRFS_EXTENT_DATA_KEY;
+       key.offset = (u64)-1;
+       ret = btrfs_search_slot(trans, tree_root, &key, &path, -1, 1);
+       if (ret < 0) {
+               error("failed to locate free space cache extent for block group %llu: %d",
+                     bg->key.objectid, ret);
+               goto out;
+       }
+       while (1) {
+               struct btrfs_file_extent_item *fi;
+               u64 disk_bytenr;
+               u64 disk_num_bytes;
+
+               ret = btrfs_previous_item(tree_root, &path, ino,
+                                         BTRFS_EXTENT_DATA_KEY);
+               if (ret > 0) {
+                       ret = 0;
+                       break;
+               }
+               if (ret < 0) {
+                       error(
+       "failed to locate free space cache extent for block group %llu: %d",
+                               bg->key.objectid, ret);
+                       goto out;
+               }
+               node = path.nodes[0];
+               slot = path.slots[0];
+               btrfs_item_key_to_cpu(node, &key, slot);
+               fi = btrfs_item_ptr(node, slot, struct btrfs_file_extent_item);
+               disk_bytenr = btrfs_file_extent_disk_bytenr(node, fi);
+               disk_num_bytes = btrfs_file_extent_disk_num_bytes(node, fi);
+
+               ret = btrfs_free_extent(trans, tree_root, disk_bytenr,
+                                       disk_num_bytes, 0, tree_root->objectid,
+                                       ino, key.offset);
+               if (ret < 0) {
+                       error("failed to remove backref for disk bytenr %llu: %d",
+                             disk_bytenr, ret);
+                       goto out;
+               }
+               ret = btrfs_del_item(trans, tree_root, &path);
+               if (ret < 0) {
+                       error(
+       "failed to remove free space extent data for ino %llu offset %llu: %d",
+                             ino, key.offset, ret);
+                       goto out;
+               }
+       }
+       btrfs_release_path(&path);
+
+       /* Now delete free space cache inode item */
+       key.objectid = ino;
+       key.type = BTRFS_INODE_ITEM_KEY;
+       key.offset = 0;
+
+       ret = btrfs_search_slot(trans, tree_root, &key, &path, -1, 1);
+       if (ret > 0)
+               warning("free space inode %llu not found, ignore", ino);
+       if (ret < 0) {
+               error(
+       "failed to locate free space cache inode %llu for block group %llu: %d",
+                     ino, bg->key.objectid, ret);
+               goto out;
+       }
+       ret = btrfs_del_item(trans, tree_root, &path);
+       if (ret < 0) {
+               error(
+       "failed to delete free space cache inode %llu for block group %llu: %d",
+                     ino, bg->key.objectid, ret);
+       }
+out:
+       btrfs_release_path(&path);
+       if (!ret)
+               btrfs_commit_transaction(trans, tree_root);
+       return ret;
+}