Btrfs: hunting slab corruption

Signed-off-by: Chris Mason <chris.mason@oracle.com>

5 files changed, 27 insertions, 6 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 1eb333e2e18b..b7f3fcb72c62 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -457,6 +457,8 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
         int ret;
         int level;
 
+        WARN_ON(p->nodes[0] != NULL);
+        WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex));
 again:
         b = root->node;
         get_bh(b);
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index c18f81797a88..18d3e168ad0a 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -35,6 +35,8 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
         btrfs_set_dir_name_len(dir_item, name_len);
         name_ptr = (char *)(dir_item + 1);
         memcpy(name_ptr, name, name_len);
+        if (name_ptr + name_len > path.nodes[0]->b_data + 4096)
+                WARN_ON(1);
         mark_buffer_dirty(path.nodes[0]);
 out:
         btrfs_release_path(root, &path);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index f5db2b936502..6c010463b9db 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3,6 +3,7 @@
 #include <linux/blkdev.h>
 #include <linux/crypto.h>
 #include <linux/scatterlist.h>
+#include <linux/swap.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -50,6 +51,8 @@ struct buffer_head *btrfs_find_tree_block(struct btrfs_root *root, u64 blocknr)
         } while (bh != head);
 out_unlock:
         unlock_page(page);
+        if (ret)
+                touch_buffer(ret);
         page_cache_release(page);
         return ret;
 }
@@ -65,6 +68,7 @@ struct buffer_head *btrfs_find_create_tree_block(struct btrfs_root *root,
         struct buffer_head *head;
         struct buffer_head *ret = NULL;
         u64 first_block = index << (PAGE_CACHE_SHIFT - blockbits);
+
         page = grab_cache_page(mapping, index);
         if (!page)
                 return NULL;
@@ -89,6 +93,8 @@ struct buffer_head *btrfs_find_create_tree_block(struct btrfs_root *root,
         } while (bh != head);
 out_unlock:
         unlock_page(page);
+        if (ret)
+                touch_buffer(ret);
         page_cache_release(page);
         return ret;
 }
@@ -139,7 +145,7 @@ int btrfs_csum_data(struct btrfs_root * root, char *data, size_t len,
         desc.flags = 0;
         sg_init_one(&sg, data, len);
         spin_lock(&root->fs_info->hash_lock);
-        ret = crypto_hash_digest(&desc, &sg, len, result);
+        ret = crypto_hash_digest(&desc, &sg, 1, result);
         spin_unlock(&root->fs_info->hash_lock);
         if (ret) {
                 printk("sha256 digest failed\n");
@@ -153,6 +159,7 @@ static int csum_tree_block(struct btrfs_root *root, struct buffer_head *bh,
         int ret;
         struct btrfs_node *node;
 
+        return 0;
         ret = btrfs_csum_data(root, bh->b_data + BTRFS_CSUM_SIZE,
                               bh->b_size - BTRFS_CSUM_SIZE, result);
         if (ret)
@@ -165,17 +172,17 @@ static int csum_tree_block(struct btrfs_root *root, struct buffer_head *bh,
                 }
         } else {
                 node = btrfs_buffer_node(bh);
-                memcpy(&node->header.csum, result, BTRFS_CSUM_SIZE);
+                memcpy(node->header.csum, result, BTRFS_CSUM_SIZE);
         }
         return 0;
 }
 
 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 {
+#if 0
         struct buffer_head *bh;
         struct btrfs_root *root = btrfs_sb(page->mapping->host->i_sb);
         struct buffer_head *head;
-
         if (!page_has_buffers(page)) {
                 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
                                         (1 << BH_Dirty)|(1 << BH_Uptodate));
@@ -187,6 +194,7 @@ static int btree_writepage(struct page *page, struct writeback_control *wbc)
                         csum_tree_block(root, bh, 0);
                 bh = bh->b_this_page;
         } while (bh != head);
+#endif
         return block_write_full_page(page, btree_get_block, wbc);
 }
 
@@ -312,6 +320,8 @@ struct btrfs_root *open_ctree(struct super_block *sb,
         fs_info->btree_inode->i_ino = 1;
         fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
+        insert_inode_hash(fs_info->btree_inode);
+
         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
         fs_info->hash_tfm = crypto_alloc_hash("sha256", 0, CRYPTO_ALG_ASYNC);
         spin_lock_init(&fs_info->hash_lock);
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 04428137d75f..ab5419eea93a 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -361,13 +361,16 @@ static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
                                    struct nameidata *nd)
 {
         struct inode * inode;
+        struct btrfs_root *root = btrfs_sb(dir->i_sb);
         ino_t ino;
         int ret;
 
         if (dentry->d_name.len > BTRFS_NAME_LEN)
                 return ERR_PTR(-ENAMETOOLONG);
 
+        mutex_lock(&root->fs_info->fs_mutex);
         ret = btrfs_inode_by_name(dir, dentry, &ino);
+        mutex_unlock(&root->fs_info->fs_mutex);
         if (ret < 0)
                 return ERR_PTR(ret);
         inode = NULL;
@@ -395,6 +398,7 @@ static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
         unsigned char d_type = DT_UNKNOWN;
         int over = 0;
 
+        mutex_lock(&root->fs_info->fs_mutex);
         key.objectid = inode->i_ino;
         key.flags = 0;
         btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
@@ -446,6 +450,7 @@ static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
         ret = 0;
 err:
         btrfs_release_path(root, &path);
+        mutex_unlock(&root->fs_info->fs_mutex);
         return ret;
 }
 
@@ -667,8 +672,8 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
                 inode->i_op = &btrfs_file_inode_operations;
         }
         dir->i_sb->s_dirt = 1;
-        btrfs_end_transaction(trans, root);
 out_unlock:
+        btrfs_end_transaction(trans, root);
         mutex_unlock(&root->fs_info->fs_mutex);
         if (drop_inode) {
                 inode_dec_link_count(inode);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index b20fb53a0d27..a146463c5049 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -197,8 +197,10 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 
                 ret = btrfs_del_root(trans, root->fs_info->tree_root,
                                      &snap_key);
-                BUG_ON(ret); root->fs_info->generation = root->root_key.offset + 1; ret = btrfs_end_transaction(trans, root); BUG_ON(ret);
-                printk("at free, total trans %d\n", total_trans);
+                BUG_ON(ret);
+                root->fs_info->generation = root->root_key.offset + 1;
+                ret = btrfs_end_transaction(trans, root);
+                BUG_ON(ret);
         }
 
         return ret;