btrfs_truncate

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

2 files changed, 114 insertions, 18 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 4d4fc48c0a31..176c6dc534ba 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -171,20 +171,21 @@ static int pin_down_block(struct btrfs_root *root, u64 blocknr, int pending)
         struct btrfs_header *header;
         struct buffer_head *bh;
 
-        bh = sb_find_get_block(root->fs_info->sb, blocknr);
-        if (bh) {
-                header = btrfs_buffer_header(bh);
-                if (btrfs_header_generation(header) ==
-                    root->fs_info->running_transaction->transid) {
+        if (!pending) {
+                bh = sb_find_get_block(root->fs_info->sb, blocknr);
+                if (bh) {
+                        header = btrfs_buffer_header(bh);
+                        if (btrfs_header_generation(header) ==
+                            root->fs_info->running_transaction->transid) {
+                                brelse(bh);
+                                return 0;
+                        }
                         brelse(bh);
-                        return 0;
                 }
-                brelse(bh);
-        }
-        if (pending)
-                err = set_radix_bit(&root->fs_info->pending_del_radix, blocknr);
-        else
                 err = set_radix_bit(&root->fs_info->pinned_radix, blocknr);
+        } else {
+                err = set_radix_bit(&root->fs_info->pending_del_radix, blocknr);
+        }
         BUG_ON(err);
         return 0;
 }
@@ -223,6 +224,7 @@ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
         BUG_ON(ei->refs == 0);
         refs = btrfs_extent_refs(ei) - 1;
         btrfs_set_extent_refs(ei, refs);
+        mark_buffer_dirty(path.nodes[0]);
         if (refs == 0) {
                 u64 super_blocks_used;
 
@@ -240,7 +242,6 @@ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
                 if (ret)
                         BUG();
         }
-        mark_buffer_dirty(path.nodes[0]);
         btrfs_release_path(extent_root, &path);
         finish_current_insert(trans, extent_root);
         return ret;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 487da5a213c0..fd3d9d616ff9 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -28,11 +28,15 @@ static void btrfs_read_locked_inode(struct inode *inode)
         struct btrfs_inode_item *inode_item;
         struct btrfs_root *root = btrfs_sb(inode->i_sb);
         int ret;
+
         btrfs_init_path(&path);
+        mutex_lock(&root->fs_info->fs_mutex);
+
         ret = btrfs_lookup_inode(NULL, root, &path, inode->i_ino, 0);
         if (ret) {
-                make_bad_inode(inode);
                 btrfs_release_path(root, &path);
+                mutex_unlock(&root->fs_info->fs_mutex);
+                make_bad_inode(inode);
                 return;
         }
         inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]),
@@ -53,6 +57,7 @@ static void btrfs_read_locked_inode(struct inode *inode)
         inode->i_blocks = btrfs_inode_nblocks(inode_item);
         inode->i_generation = btrfs_inode_generation(inode_item);
         btrfs_release_path(root, &path);
+        mutex_unlock(&root->fs_info->fs_mutex);
         switch (inode->i_mode & S_IFMT) {
 #if 0
         default:
@@ -151,20 +156,85 @@ error:
         return ret;
 }
 
+static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
+                                   struct btrfs_root *root,
+                                   struct inode *inode)
+{
+        int ret;
+        struct btrfs_path path;
+        struct btrfs_key key;
+        struct btrfs_disk_key *found_key;
+        struct btrfs_leaf *leaf;
+        struct btrfs_file_extent_item *fi;
+        u64 extent_start;
+        u64 extent_num_blocks;
+
+        /* FIXME, add redo link to tree so we don't leak on crash */
+        key.objectid = inode->i_ino;
+        key.offset = (u64)-1;
+        key.flags = 0;
+        btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
+        while(1) {
+                btrfs_init_path(&path);
+                ret = btrfs_search_slot(trans, root, &key, &path, -1, 1);
+                if (ret < 0) {
+                        btrfs_release_path(root, &path);
+                        goto error;
+                }
+                if (ret > 0) {
+                        BUG_ON(path.slots[0] == 0);
+                        path.slots[0]--;
+                }
+                leaf = btrfs_buffer_leaf(path.nodes[0]);
+                found_key = &leaf->items[path.slots[0]].key;
+                if (btrfs_disk_key_objectid(found_key) != inode->i_ino)
+                        break;
+                if (btrfs_disk_key_type(found_key) != BTRFS_EXTENT_DATA_KEY)
+                        break;
+                if (btrfs_disk_key_offset(found_key) < inode->i_size)
+                        break;
+                /* FIXME: add extent truncation */
+                if (btrfs_disk_key_offset(found_key) < inode->i_size)
+                        break;
+                fi = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]),
+                                    path.slots[0],
+                                    struct btrfs_file_extent_item);
+                extent_start = btrfs_file_extent_disk_blocknr(fi);
+                extent_num_blocks = btrfs_file_extent_disk_num_blocks(fi);
+                key.offset = btrfs_disk_key_offset(found_key) - 1;
+                ret = btrfs_del_item(trans, root, &path);
+                BUG_ON(ret);
+                inode->i_blocks -= btrfs_file_extent_num_blocks(fi) >> 9;
+                btrfs_release_path(root, &path);
+                ret = btrfs_free_extent(trans, root, extent_start,
+                                        extent_num_blocks, 0);
+                BUG_ON(ret);
+                if (btrfs_disk_key_offset(found_key) == 0)
+                        break;
+        }
+        btrfs_release_path(root, &path);
+        ret = 0;
+error:
+        return ret;
+}
+
 static void btrfs_delete_inode(struct inode *inode)
 {
         struct btrfs_trans_handle *trans;
         struct btrfs_root *root = btrfs_sb(inode->i_sb);
+        int ret;
+
         truncate_inode_pages(&inode->i_data, 0);
         if (is_bad_inode(inode)) {
                 goto no_delete;
         }
         inode->i_size = 0;
-        if (inode->i_blocks)
-                WARN_ON(1);
-
         mutex_lock(&root->fs_info->fs_mutex);
         trans = btrfs_start_transaction(root, 1);
+        if (S_ISREG(inode->i_mode)) {
+                ret = btrfs_truncate_in_trans(trans, root, inode);
+                BUG_ON(ret);
+        }
         btrfs_free_inode(trans, root, inode);
         btrfs_end_transaction(trans, root);
         mutex_unlock(&root->fs_info->fs_mutex);
@@ -173,7 +243,6 @@ no_delete:
         clear_inode(inode);
 }
 
-
 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
                               ino_t *ino)
 {
@@ -688,6 +757,8 @@ allocate:
                 err = ret;
                 goto out;
         }
+        inode->i_blocks += inode->i_sb->s_blocksize >> 9;
+        set_buffer_new(result);
         map_bh(result, inode->i_sb, blocknr);
 
 out:
@@ -724,6 +795,30 @@ static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
         return nobh_writepage(page, btrfs_get_block, wbc);
 }
 
+static void btrfs_truncate(struct inode *inode)
+{
+        struct btrfs_root *root = btrfs_sb(inode->i_sb);
+        int ret;
+        struct btrfs_trans_handle *trans;
+
+        if (!S_ISREG(inode->i_mode))
+                return;
+        if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+                return;
+
+        nobh_truncate_page(inode->i_mapping, inode->i_size);
+
+        /* FIXME, add redo link to tree so we don't leak on crash */
+        mutex_lock(&root->fs_info->fs_mutex);
+        trans = btrfs_start_transaction(root, 1);
+        ret = btrfs_truncate_in_trans(trans, root, inode);
+        BUG_ON(ret);
+        ret = btrfs_end_transaction(trans, root);
+        BUG_ON(ret);
+        mutex_unlock(&root->fs_info->fs_mutex);
+        mark_inode_dirty(inode);
+}
+
 static int btrfs_get_sb(struct file_system_type *fs_type,
         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 {
@@ -772,7 +867,7 @@ static struct address_space_operations btrfs_aops = {
 };
 
 static struct inode_operations btrfs_file_inode_operations = {
-        .truncate       = NULL,
+        .truncate       = btrfs_truncate,
 };
 
 static struct file_operations btrfs_file_operations = {