Commit 4b52dff6 authored by Chris Mason's avatar Chris Mason Committed by David Woodhouse

Btrfs: Fix super block updates during transaction commit

The super block written during commit was not consistent with the state of
the trees.  This change adds an in-memory copy of the super so that we can
make sure to write out consistent data during a commit.
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 79c44584
...@@ -306,6 +306,7 @@ struct btrfs_fs_info { ...@@ -306,6 +306,7 @@ struct btrfs_fs_info {
u64 generation; u64 generation;
struct btrfs_transaction *running_transaction; struct btrfs_transaction *running_transaction;
struct btrfs_super_block *disk_super; struct btrfs_super_block *disk_super;
struct btrfs_super_block super_copy;
struct buffer_head *sb_buffer; struct buffer_head *sb_buffer;
struct super_block *sb; struct super_block *sb;
struct inode *btree_inode; struct inode *btree_inode;
......
...@@ -471,6 +471,8 @@ struct btrfs_root *open_ctree(struct super_block *sb) ...@@ -471,6 +471,8 @@ struct btrfs_root *open_ctree(struct super_block *sb)
if (!fs_info->sb_buffer) if (!fs_info->sb_buffer)
goto fail_iput; goto fail_iput;
disk_super = (struct btrfs_super_block *)fs_info->sb_buffer->b_data; disk_super = (struct btrfs_super_block *)fs_info->sb_buffer->b_data;
fs_info->disk_super = disk_super;
memcpy(&fs_info->super_copy, disk_super, sizeof(fs_info->super_copy));
if (!btrfs_super_root(disk_super)) if (!btrfs_super_root(disk_super))
goto fail_sb_buffer; goto fail_sb_buffer;
...@@ -479,7 +481,6 @@ struct btrfs_root *open_ctree(struct super_block *sb) ...@@ -479,7 +481,6 @@ struct btrfs_root *open_ctree(struct super_block *sb)
btrfs_super_total_blocks(disk_super) << btrfs_super_total_blocks(disk_super) <<
fs_info->btree_inode->i_blkbits); fs_info->btree_inode->i_blkbits);
fs_info->disk_super = disk_super;
if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC, if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
sizeof(disk_super->magic))) { sizeof(disk_super->magic))) {
...@@ -527,8 +528,6 @@ int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root ...@@ -527,8 +528,6 @@ int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
int ret; int ret;
struct buffer_head *bh = root->fs_info->sb_buffer; struct buffer_head *bh = root->fs_info->sb_buffer;
btrfs_set_super_root(root->fs_info->disk_super,
bh_blocknr(root->fs_info->tree_root->node));
lock_buffer(bh); lock_buffer(bh);
WARN_ON(atomic_read(&bh->b_count) < 1); WARN_ON(atomic_read(&bh->b_count) < 1);
clear_buffer_dirty(bh); clear_buffer_dirty(bh);
......
...@@ -796,8 +796,8 @@ static int finish_current_insert(struct btrfs_trans_handle *trans, struct ...@@ -796,8 +796,8 @@ static int finish_current_insert(struct btrfs_trans_handle *trans, struct
for (i = 0; i < extent_root->fs_info->extent_tree_insert_nr; i++) { for (i = 0; i < extent_root->fs_info->extent_tree_insert_nr; i++) {
ins.objectid = extent_root->fs_info->extent_tree_insert[i]; ins.objectid = extent_root->fs_info->extent_tree_insert[i];
super_blocks_used = btrfs_super_blocks_used(info->disk_super); super_blocks_used = btrfs_super_blocks_used(&info->super_copy);
btrfs_set_super_blocks_used(info->disk_super, btrfs_set_super_blocks_used(&info->super_copy,
super_blocks_used + 1); super_blocks_used + 1);
ret = btrfs_insert_item(trans, extent_root, &ins, &extent_item, ret = btrfs_insert_item(trans, extent_root, &ins, &extent_item,
sizeof(extent_item)); sizeof(extent_item));
...@@ -892,8 +892,8 @@ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root ...@@ -892,8 +892,8 @@ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
BUG_ON(ret); BUG_ON(ret);
} }
super_blocks_used = btrfs_super_blocks_used(info->disk_super); super_blocks_used = btrfs_super_blocks_used(&info->super_copy);
btrfs_set_super_blocks_used(info->disk_super, btrfs_set_super_blocks_used(&info->super_copy,
super_blocks_used - num_blocks); super_blocks_used - num_blocks);
ret = btrfs_del_item(trans, extent_root, path); ret = btrfs_del_item(trans, extent_root, path);
if (ret) { if (ret) {
...@@ -1032,7 +1032,7 @@ static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root ...@@ -1032,7 +1032,7 @@ static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
info->extent_tree_prealloc_nr = 0; info->extent_tree_prealloc_nr = 0;
} }
if (search_end == (u64)-1) if (search_end == (u64)-1)
search_end = btrfs_super_total_blocks(info->disk_super); search_end = btrfs_super_total_blocks(&info->super_copy);
if (hint_block) { if (hint_block) {
block_group = btrfs_lookup_block_group(info, hint_block); block_group = btrfs_lookup_block_group(info, hint_block);
block_group = btrfs_find_block_group(root, block_group, block_group = btrfs_find_block_group(root, block_group,
...@@ -1361,8 +1361,8 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans, ...@@ -1361,8 +1361,8 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
} }
} }
super_blocks_used = btrfs_super_blocks_used(info->disk_super); super_blocks_used = btrfs_super_blocks_used(&info->super_copy);
btrfs_set_super_blocks_used(info->disk_super, super_blocks_used + btrfs_set_super_blocks_used(&info->super_copy, super_blocks_used +
num_blocks); num_blocks);
ret = btrfs_insert_item(trans, extent_root, ins, &extent_item, ret = btrfs_insert_item(trans, extent_root, ins, &extent_item,
sizeof(extent_item)); sizeof(extent_item));
...@@ -1737,7 +1737,7 @@ int btrfs_read_block_groups(struct btrfs_root *root) ...@@ -1737,7 +1737,7 @@ int btrfs_read_block_groups(struct btrfs_root *root)
BTRFS_BLOCK_GROUP_AVAIL); BTRFS_BLOCK_GROUP_AVAIL);
} }
if (key.objectid >= if (key.objectid >=
btrfs_super_total_blocks(info->disk_super)) btrfs_super_total_blocks(&info->super_copy))
break; break;
} }
......
...@@ -144,7 +144,7 @@ static int btrfs_get_sb(struct file_system_type *fs_type, ...@@ -144,7 +144,7 @@ static int btrfs_get_sb(struct file_system_type *fs_type,
static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{ {
struct btrfs_root *root = btrfs_sb(dentry->d_sb); struct btrfs_root *root = btrfs_sb(dentry->d_sb);
struct btrfs_super_block *disk_super = root->fs_info->disk_super; struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
buf->f_namelen = BTRFS_NAME_LEN; buf->f_namelen = BTRFS_NAME_LEN;
buf->f_blocks = btrfs_super_total_blocks(disk_super); buf->f_blocks = btrfs_super_total_blocks(disk_super);
......
...@@ -380,6 +380,12 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans, ...@@ -380,6 +380,12 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
else else
prev_trans->use_count++; prev_trans->use_count++;
} }
btrfs_set_super_generation(&root->fs_info->super_copy,
cur_trans->transid);
btrfs_set_super_root(&root->fs_info->super_copy,
bh_blocknr(root->fs_info->tree_root->node));
memcpy(root->fs_info->disk_super, &root->fs_info->super_copy,
sizeof(root->fs_info->super_copy));
mutex_unlock(&root->fs_info->trans_mutex); mutex_unlock(&root->fs_info->trans_mutex);
mutex_unlock(&root->fs_info->fs_mutex); mutex_unlock(&root->fs_info->fs_mutex);
ret = btrfs_write_and_wait_transaction(trans, root); ret = btrfs_write_and_wait_transaction(trans, root);
...@@ -389,8 +395,6 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans, ...@@ -389,8 +395,6 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
put_transaction(prev_trans); put_transaction(prev_trans);
mutex_unlock(&root->fs_info->trans_mutex); mutex_unlock(&root->fs_info->trans_mutex);
} }
btrfs_set_super_generation(root->fs_info->disk_super,
cur_trans->transid);
BUG_ON(ret); BUG_ON(ret);
write_ctree_super(trans, root); write_ctree_super(trans, root);
......
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