Btrfs: split up super.c
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
new file mode 100644
index 0000000..62a3a77
--- /dev/null
+++ b/fs/btrfs/inode.c
@@ -0,0 +1,2210 @@
+#include <linux/module.h>
+#include <linux/buffer_head.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/smp_lock.h>
+#include <linux/backing-dev.h>
+#include <linux/mpage.h>
+#include <linux/swap.h>
+#include <linux/writeback.h>
+#include <linux/statfs.h>
+#include <linux/compat.h>
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "btrfs_inode.h"
+#include "ioctl.h"
+#include "print-tree.h"
+
+struct btrfs_iget_args {
+ u64 ino;
+ struct btrfs_root *root;
+};
+
+static struct inode_operations btrfs_dir_inode_operations;
+static struct inode_operations btrfs_symlink_inode_operations;
+static struct inode_operations btrfs_dir_ro_inode_operations;
+static struct inode_operations btrfs_file_inode_operations;
+static struct address_space_operations btrfs_aops;
+static struct address_space_operations btrfs_symlink_aops;
+static struct file_operations btrfs_dir_file_operations;
+
+static struct kmem_cache *btrfs_inode_cachep;
+struct kmem_cache *btrfs_trans_handle_cachep;
+struct kmem_cache *btrfs_transaction_cachep;
+struct kmem_cache *btrfs_bit_radix_cachep;
+struct kmem_cache *btrfs_path_cachep;
+
+#define S_SHIFT 12
+static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
+ [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
+ [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
+ [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
+ [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
+ [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
+ [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
+ [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
+};
+
+void btrfs_read_locked_inode(struct inode *inode)
+{
+ struct btrfs_path *path;
+ struct btrfs_inode_item *inode_item;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_key location;
+ u64 alloc_group_block;
+ int ret;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ btrfs_init_path(path);
+ mutex_lock(&root->fs_info->fs_mutex);
+
+ memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
+ ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
+ if (ret) {
+ btrfs_free_path(path);
+ goto make_bad;
+ }
+ inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
+ path->slots[0],
+ struct btrfs_inode_item);
+
+ inode->i_mode = btrfs_inode_mode(inode_item);
+ inode->i_nlink = btrfs_inode_nlink(inode_item);
+ inode->i_uid = btrfs_inode_uid(inode_item);
+ inode->i_gid = btrfs_inode_gid(inode_item);
+ inode->i_size = btrfs_inode_size(inode_item);
+ inode->i_atime.tv_sec = btrfs_timespec_sec(&inode_item->atime);
+ inode->i_atime.tv_nsec = btrfs_timespec_nsec(&inode_item->atime);
+ inode->i_mtime.tv_sec = btrfs_timespec_sec(&inode_item->mtime);
+ inode->i_mtime.tv_nsec = btrfs_timespec_nsec(&inode_item->mtime);
+ inode->i_ctime.tv_sec = btrfs_timespec_sec(&inode_item->ctime);
+ inode->i_ctime.tv_nsec = btrfs_timespec_nsec(&inode_item->ctime);
+ inode->i_blocks = btrfs_inode_nblocks(inode_item);
+ inode->i_generation = btrfs_inode_generation(inode_item);
+ alloc_group_block = btrfs_inode_block_group(inode_item);
+ BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
+ alloc_group_block);
+
+ btrfs_free_path(path);
+ inode_item = NULL;
+
+ mutex_unlock(&root->fs_info->fs_mutex);
+
+ switch (inode->i_mode & S_IFMT) {
+#if 0
+ default:
+ init_special_inode(inode, inode->i_mode,
+ btrfs_inode_rdev(inode_item));
+ break;
+#endif
+ case S_IFREG:
+ inode->i_mapping->a_ops = &btrfs_aops;
+ inode->i_fop = &btrfs_file_operations;
+ inode->i_op = &btrfs_file_inode_operations;
+ break;
+ case S_IFDIR:
+ inode->i_fop = &btrfs_dir_file_operations;
+ if (root == root->fs_info->tree_root)
+ inode->i_op = &btrfs_dir_ro_inode_operations;
+ else
+ inode->i_op = &btrfs_dir_inode_operations;
+ break;
+ case S_IFLNK:
+ inode->i_op = &btrfs_symlink_inode_operations;
+ inode->i_mapping->a_ops = &btrfs_symlink_aops;
+ break;
+ }
+ return;
+
+make_bad:
+ btrfs_release_path(root, path);
+ btrfs_free_path(path);
+ mutex_unlock(&root->fs_info->fs_mutex);
+ make_bad_inode(inode);
+}
+
+static void fill_inode_item(struct btrfs_inode_item *item,
+ struct inode *inode)
+{
+ btrfs_set_inode_uid(item, inode->i_uid);
+ btrfs_set_inode_gid(item, inode->i_gid);
+ btrfs_set_inode_size(item, inode->i_size);
+ btrfs_set_inode_mode(item, inode->i_mode);
+ btrfs_set_inode_nlink(item, inode->i_nlink);
+ btrfs_set_timespec_sec(&item->atime, inode->i_atime.tv_sec);
+ btrfs_set_timespec_nsec(&item->atime, inode->i_atime.tv_nsec);
+ btrfs_set_timespec_sec(&item->mtime, inode->i_mtime.tv_sec);
+ btrfs_set_timespec_nsec(&item->mtime, inode->i_mtime.tv_nsec);
+ btrfs_set_timespec_sec(&item->ctime, inode->i_ctime.tv_sec);
+ btrfs_set_timespec_nsec(&item->ctime, inode->i_ctime.tv_nsec);
+ btrfs_set_inode_nblocks(item, inode->i_blocks);
+ btrfs_set_inode_generation(item, inode->i_generation);
+ btrfs_set_inode_block_group(item,
+ BTRFS_I(inode)->block_group->key.objectid);
+}
+
+static int btrfs_update_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode)
+{
+ struct btrfs_inode_item *inode_item;
+ struct btrfs_path *path;
+ int ret;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ btrfs_init_path(path);
+ ret = btrfs_lookup_inode(trans, root, path,
+ &BTRFS_I(inode)->location, 1);
+ if (ret) {
+ if (ret > 0)
+ ret = -ENOENT;
+ goto failed;
+ }
+
+ inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
+ path->slots[0],
+ struct btrfs_inode_item);
+
+ fill_inode_item(inode_item, inode);
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+ ret = 0;
+failed:
+ btrfs_release_path(root, path);
+ btrfs_free_path(path);
+ return ret;
+}
+
+
+static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *dir,
+ struct dentry *dentry)
+{
+ struct btrfs_path *path;
+ const char *name = dentry->d_name.name;
+ int name_len = dentry->d_name.len;
+ int ret = 0;
+ u64 objectid;
+ struct btrfs_dir_item *di;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ btrfs_init_path(path);
+ di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
+ name, name_len, -1);
+ if (IS_ERR(di)) {
+ ret = PTR_ERR(di);
+ goto err;
+ }
+ if (!di) {
+ ret = -ENOENT;
+ goto err;
+ }
+ objectid = btrfs_disk_key_objectid(&di->location);
+ ret = btrfs_delete_one_dir_name(trans, root, path, di);
+ BUG_ON(ret);
+ btrfs_release_path(root, path);
+
+ di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
+ objectid, name, name_len, -1);
+ if (IS_ERR(di)) {
+ ret = PTR_ERR(di);
+ goto err;
+ }
+ if (!di) {
+ ret = -ENOENT;
+ goto err;
+ }
+ ret = btrfs_delete_one_dir_name(trans, root, path, di);
+ BUG_ON(ret);
+
+ dentry->d_inode->i_ctime = dir->i_ctime;
+err:
+ btrfs_free_path(path);
+ if (!ret) {
+ dir->i_size -= name_len * 2;
+ btrfs_update_inode(trans, root, dir);
+ drop_nlink(dentry->d_inode);
+ btrfs_update_inode(trans, root, dentry->d_inode);
+ dir->i_sb->s_dirt = 1;
+ }
+ return ret;
+}
+
+static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+ struct btrfs_root *root;
+ struct btrfs_trans_handle *trans;
+ int ret;
+
+ root = BTRFS_I(dir)->root;
+ mutex_lock(&root->fs_info->fs_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, dir);
+ ret = btrfs_unlink_trans(trans, root, dir, dentry);
+ btrfs_end_transaction(trans, root);
+ mutex_unlock(&root->fs_info->fs_mutex);
+ btrfs_btree_balance_dirty(root);
+ return ret;
+}
+
+static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+ struct inode *inode = dentry->d_inode;
+ int err;
+ int ret;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_key found_key;
+ int found_type;
+ struct btrfs_leaf *leaf;
+ char *goodnames = "..";
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ btrfs_init_path(path);
+ mutex_lock(&root->fs_info->fs_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, dir);
+ key.objectid = inode->i_ino;
+ key.offset = (u64)-1;
+ key.flags = (u32)-1;
+ while(1) {
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret < 0) {
+ err = ret;
+ goto out;
+ }
+ BUG_ON(ret == 0);
+ if (path->slots[0] == 0) {
+ err = -ENOENT;
+ goto out;
+ }
+ path->slots[0]--;
+ leaf = btrfs_buffer_leaf(path->nodes[0]);
+ btrfs_disk_key_to_cpu(&found_key,
+ &leaf->items[path->slots[0]].key);
+ found_type = btrfs_key_type(&found_key);
+ if (found_key.objectid != inode->i_ino) {
+ err = -ENOENT;
+ goto out;
+ }
+ if ((found_type != BTRFS_DIR_ITEM_KEY &&
+ found_type != BTRFS_DIR_INDEX_KEY) ||
+ (!btrfs_match_dir_item_name(root, path, goodnames, 2) &&
+ !btrfs_match_dir_item_name(root, path, goodnames, 1))) {
+ err = -ENOTEMPTY;
+ goto out;
+ }
+ ret = btrfs_del_item(trans, root, path);
+ BUG_ON(ret);
+
+ if (found_type == BTRFS_DIR_ITEM_KEY && found_key.offset == 1)
+ break;
+ btrfs_release_path(root, path);
+ }
+ ret = 0;
+ btrfs_release_path(root, path);
+
+ /* now the directory is empty */
+ err = btrfs_unlink_trans(trans, root, dir, dentry);
+ if (!err) {
+ inode->i_size = 0;
+ }
+out:
+ btrfs_release_path(root, path);
+ btrfs_free_path(path);
+ mutex_unlock(&root->fs_info->fs_mutex);
+ ret = btrfs_end_transaction(trans, root);
+ btrfs_btree_balance_dirty(root);
+ if (ret && !err)
+ err = ret;
+ return err;
+}
+
+static int btrfs_free_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode)
+{
+ struct btrfs_path *path;
+ int ret;
+
+ clear_inode(inode);
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ btrfs_init_path(path);
+ ret = btrfs_lookup_inode(trans, root, path,
+ &BTRFS_I(inode)->location, -1);
+ BUG_ON(ret);
+ ret = btrfs_del_item(trans, root, path);
+ BUG_ON(ret);
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * truncates go from a high offset to a low offset. So, walk
+ * from hi to lo in the node and issue readas. Stop when you find
+ * keys from a different objectid
+ */
+static void reada_truncate(struct btrfs_root *root, struct btrfs_path *path,
+ u64 objectid)
+{
+ struct btrfs_node *node;
+ int i;
+ int nritems;
+ u64 item_objectid;
+ u64 blocknr;
+ int slot;
+ int ret;
+
+ if (!path->nodes[1])
+ return;
+ node = btrfs_buffer_node(path->nodes[1]);
+ slot = path->slots[1];
+ if (slot == 0)
+ return;
+ nritems = btrfs_header_nritems(&node->header);
+ for (i = slot - 1; i >= 0; i--) {
+ item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key);
+ if (item_objectid != objectid)
+ break;
+ blocknr = btrfs_node_blockptr(node, i);
+ ret = readahead_tree_block(root, blocknr);
+ if (ret)
+ break;
+ }
+}
+
+/*
+ * this can truncate away extent items, csum items and directory items.
+ * It starts at a high offset and removes keys until it can't find
+ * any higher than i_size.
+ *
+ * csum items that cross the new i_size are truncated to the new size
+ * as well.
+ */
+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;
+ u32 found_type;
+ struct btrfs_leaf *leaf;
+ struct btrfs_file_extent_item *fi;
+ u64 extent_start = 0;
+ u64 extent_num_blocks = 0;
+ u64 item_end = 0;
+ int found_extent;
+ int del_item;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ /* FIXME, add redo link to tree so we don't leak on crash */
+ key.objectid = inode->i_ino;
+ key.offset = (u64)-1;
+ key.flags = (u32)-1;
+ while(1) {
+ btrfs_init_path(path);
+ fi = NULL;
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret < 0) {
+ goto error;
+ }
+ if (ret > 0) {
+ BUG_ON(path->slots[0] == 0);
+ path->slots[0]--;
+ }
+ reada_truncate(root, path, inode->i_ino);
+ leaf = btrfs_buffer_leaf(path->nodes[0]);
+ found_key = &leaf->items[path->slots[0]].key;
+ found_type = btrfs_disk_key_type(found_key);
+
+ if (btrfs_disk_key_objectid(found_key) != inode->i_ino)
+ break;
+ if (found_type != BTRFS_CSUM_ITEM_KEY &&
+ found_type != BTRFS_DIR_ITEM_KEY &&
+ found_type != BTRFS_DIR_INDEX_KEY &&
+ found_type != BTRFS_EXTENT_DATA_KEY)
+ break;
+
+ item_end = btrfs_disk_key_offset(found_key);
+ if (found_type == BTRFS_EXTENT_DATA_KEY) {
+ fi = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
+ path->slots[0],
+ struct btrfs_file_extent_item);
+ if (btrfs_file_extent_type(fi) !=
+ BTRFS_FILE_EXTENT_INLINE) {
+ item_end += btrfs_file_extent_num_blocks(fi) <<
+ inode->i_blkbits;
+ }
+ }
+ if (found_type == BTRFS_CSUM_ITEM_KEY) {
+ ret = btrfs_csum_truncate(trans, root, path,
+ inode->i_size);
+ BUG_ON(ret);
+ }
+ if (item_end < inode->i_size) {
+ if (found_type) {
+ btrfs_set_key_type(&key, found_type - 1);
+ continue;
+ }
+ break;
+ }
+ if (btrfs_disk_key_offset(found_key) >= inode->i_size)
+ del_item = 1;
+ else
+ del_item = 0;
+ found_extent = 0;
+
+ /* FIXME, shrink the extent if the ref count is only 1 */
+ if (found_type == BTRFS_EXTENT_DATA_KEY &&
+ btrfs_file_extent_type(fi) !=
+ BTRFS_FILE_EXTENT_INLINE) {
+ u64 num_dec;
+ if (!del_item) {
+ u64 orig_num_blocks =
+ btrfs_file_extent_num_blocks(fi);
+ extent_num_blocks = inode->i_size -
+ btrfs_disk_key_offset(found_key) +
+ root->blocksize - 1;
+ extent_num_blocks >>= inode->i_blkbits;
+ btrfs_set_file_extent_num_blocks(fi,
+ extent_num_blocks);
+ inode->i_blocks -= (orig_num_blocks -
+ extent_num_blocks) << 3;
+ mark_buffer_dirty(path->nodes[0]);
+ } else {
+ extent_start =
+ btrfs_file_extent_disk_blocknr(fi);
+ extent_num_blocks =
+ btrfs_file_extent_disk_num_blocks(fi);
+ /* FIXME blocksize != 4096 */
+ num_dec = btrfs_file_extent_num_blocks(fi) << 3;
+ if (extent_start != 0) {
+ found_extent = 1;
+ inode->i_blocks -= num_dec;
+ }
+ }
+ }
+ if (del_item) {
+ ret = btrfs_del_item(trans, root, path);
+ BUG_ON(ret);
+ } else {
+ break;
+ }
+ btrfs_release_path(root, path);
+ if (found_extent) {
+ ret = btrfs_free_extent(trans, root, extent_start,
+ extent_num_blocks, 0);
+ BUG_ON(ret);
+ }
+ }
+ ret = 0;
+error:
+ btrfs_release_path(root, path);
+ btrfs_free_path(path);
+ inode->i_sb->s_dirt = 1;
+ return ret;
+}
+
+/*
+ * taken from block_truncate_page, but does cow as it zeros out
+ * any bytes left in the last page in the file.
+ */
+static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
+{
+ struct inode *inode = mapping->host;
+ unsigned blocksize = 1 << inode->i_blkbits;
+ pgoff_t index = from >> PAGE_CACHE_SHIFT;
+ unsigned offset = from & (PAGE_CACHE_SIZE-1);
+ struct page *page;
+ char *kaddr;
+ int ret = 0;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ u64 alloc_hint = 0;
+ struct btrfs_key ins;
+ struct btrfs_trans_handle *trans;
+
+ if ((offset & (blocksize - 1)) == 0)
+ goto out;
+
+ ret = -ENOMEM;
+ page = grab_cache_page(mapping, index);
+ if (!page)
+ goto out;
+
+ if (!PageUptodate(page)) {
+ ret = mpage_readpage(page, btrfs_get_block);
+ lock_page(page);
+ if (!PageUptodate(page)) {
+ ret = -EIO;
+ goto out;
+ }
+ }
+ mutex_lock(&root->fs_info->fs_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, inode);
+
+ ret = btrfs_drop_extents(trans, root, inode,
+ page->index << PAGE_CACHE_SHIFT,
+ (page->index + 1) << PAGE_CACHE_SHIFT,
+ &alloc_hint);
+ BUG_ON(ret);
+ ret = btrfs_alloc_extent(trans, root, inode->i_ino, 1,
+ alloc_hint, (u64)-1, &ins, 1);
+ BUG_ON(ret);
+ ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
+ page->index << PAGE_CACHE_SHIFT,
+ ins.objectid, 1, 1);
+ BUG_ON(ret);
+ SetPageChecked(page);
+ kaddr = kmap(page);
+ memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
+ flush_dcache_page(page);
+ btrfs_csum_file_block(trans, root, inode->i_ino,
+ page->index << PAGE_CACHE_SHIFT,
+ kaddr, PAGE_CACHE_SIZE);
+ kunmap(page);
+ btrfs_end_transaction(trans, root);
+ mutex_unlock(&root->fs_info->fs_mutex);
+
+ set_page_dirty(page);
+ unlock_page(page);
+ page_cache_release(page);
+out:
+ return ret;
+}
+
+static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
+{
+ struct inode *inode = dentry->d_inode;
+ int err;
+
+ err = inode_change_ok(inode, attr);
+ if (err)
+ return err;
+
+ if (S_ISREG(inode->i_mode) &&
+ attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ u64 mask = root->blocksize - 1;
+ u64 pos = (inode->i_size + mask) & ~mask;
+ u64 hole_size;
+
+ if (attr->ia_size <= pos)
+ goto out;
+
+ btrfs_truncate_page(inode->i_mapping, inode->i_size);
+
+ hole_size = (attr->ia_size - pos + mask) & ~mask;
+ hole_size >>= inode->i_blkbits;
+
+ mutex_lock(&root->fs_info->fs_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, inode);
+ err = btrfs_insert_file_extent(trans, root, inode->i_ino,
+ pos, 0, 0, hole_size);
+ BUG_ON(err);
+ btrfs_end_transaction(trans, root);
+ mutex_unlock(&root->fs_info->fs_mutex);
+ }
+out:
+ err = inode_setattr(inode, attr);
+
+ return err;
+}
+void btrfs_delete_inode(struct inode *inode)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret;
+
+ truncate_inode_pages(&inode->i_data, 0);
+ if (is_bad_inode(inode)) {
+ goto no_delete;
+ }
+ inode->i_size = 0;
+ mutex_lock(&root->fs_info->fs_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, inode);
+ 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);
+ btrfs_btree_balance_dirty(root);
+ return;
+no_delete:
+ clear_inode(inode);
+}
+
+/*
+ * this returns the key found in the dir entry in the location pointer.
+ * If no dir entries were found, location->objectid is 0.
+ */
+static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
+ struct btrfs_key *location)
+{
+ const char *name = dentry->d_name.name;
+ int namelen = dentry->d_name.len;
+ struct btrfs_dir_item *di;
+ struct btrfs_path *path;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ int ret;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ btrfs_init_path(path);
+ di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
+ namelen, 0);
+ if (!di || IS_ERR(di)) {
+ location->objectid = 0;
+ ret = 0;
+ goto out;
+ }
+ btrfs_disk_key_to_cpu(location, &di->location);
+out:
+ btrfs_release_path(root, path);
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * when we hit a tree root in a directory, the btrfs part of the inode
+ * needs to be changed to reflect the root directory of the tree root. This
+ * is kind of like crossing a mount point.
+ */
+static int fixup_tree_root_location(struct btrfs_root *root,
+ struct btrfs_key *location,
+ struct btrfs_root **sub_root)
+{
+ struct btrfs_path *path;
+ struct btrfs_root_item *ri;
+
+ if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
+ return 0;
+ if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
+ return 0;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ mutex_lock(&root->fs_info->fs_mutex);
+
+ *sub_root = btrfs_read_fs_root(root->fs_info, location);
+ if (IS_ERR(*sub_root))
+ return PTR_ERR(*sub_root);
+
+ ri = &(*sub_root)->root_item;
+ location->objectid = btrfs_root_dirid(ri);
+ location->flags = 0;
+ btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
+ location->offset = 0;
+
+ btrfs_free_path(path);
+ mutex_unlock(&root->fs_info->fs_mutex);
+ return 0;
+}
+
+static int btrfs_init_locked_inode(struct inode *inode, void *p)
+{
+ struct btrfs_iget_args *args = p;
+ inode->i_ino = args->ino;
+ BTRFS_I(inode)->root = args->root;
+ return 0;
+}
+
+static int btrfs_find_actor(struct inode *inode, void *opaque)
+{
+ struct btrfs_iget_args *args = opaque;
+ return (args->ino == inode->i_ino &&
+ args->root == BTRFS_I(inode)->root);
+}
+
+struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
+ struct btrfs_root *root)
+{
+ struct inode *inode;
+ struct btrfs_iget_args args;
+ args.ino = objectid;
+ args.root = root;
+
+ inode = iget5_locked(s, objectid, btrfs_find_actor,
+ btrfs_init_locked_inode,
+ (void *)&args);
+ return inode;
+}
+
+static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
+ struct nameidata *nd)
+{
+ struct inode * inode;
+ struct btrfs_inode *bi = BTRFS_I(dir);
+ struct btrfs_root *root = bi->root;
+ struct btrfs_root *sub_root = root;
+ struct btrfs_key location;
+ 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, &location);
+ mutex_unlock(&root->fs_info->fs_mutex);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ inode = NULL;
+ if (location.objectid) {
+ ret = fixup_tree_root_location(root, &location, &sub_root);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ if (ret > 0)
+ return ERR_PTR(-ENOENT);
+ inode = btrfs_iget_locked(dir->i_sb, location.objectid,
+ sub_root);
+ if (!inode)
+ return ERR_PTR(-EACCES);
+ if (inode->i_state & I_NEW) {
+ /* the inode and parent dir are two different roots */
+ if (sub_root != root) {
+ igrab(inode);
+ sub_root->inode = inode;
+ }
+ BTRFS_I(inode)->root = sub_root;
+ memcpy(&BTRFS_I(inode)->location, &location,
+ sizeof(location));
+ btrfs_read_locked_inode(inode);
+ unlock_new_inode(inode);
+ }
+ }
+ return d_splice_alias(inode, dentry);
+}
+
+/*
+ * readahead one full node of leaves as long as their keys include
+ * the objectid supplied
+ */
+static void reada_leaves(struct btrfs_root *root, struct btrfs_path *path,
+ u64 objectid)
+{
+ struct btrfs_node *node;
+ int i;
+ u32 nritems;
+ u64 item_objectid;
+ u64 blocknr;
+ int slot;
+ int ret;
+
+ if (!path->nodes[1])
+ return;
+ node = btrfs_buffer_node(path->nodes[1]);
+ slot = path->slots[1];
+ nritems = btrfs_header_nritems(&node->header);
+ for (i = slot + 1; i < nritems; i++) {
+ item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key);
+ if (item_objectid != objectid)
+ break;
+ blocknr = btrfs_node_blockptr(node, i);
+ ret = readahead_tree_block(root, blocknr);
+ if (ret)
+ break;
+ }
+}
+static unsigned char btrfs_filetype_table[] = {
+ DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
+};
+
+static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
+{
+ struct inode *inode = filp->f_path.dentry->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_item *item;
+ struct btrfs_dir_item *di;
+ struct btrfs_key key;
+ struct btrfs_path *path;
+ int ret;
+ u32 nritems;
+ struct btrfs_leaf *leaf;
+ int slot;
+ int advance;
+ unsigned char d_type;
+ int over = 0;
+ u32 di_cur;
+ u32 di_total;
+ u32 di_len;
+ int key_type = BTRFS_DIR_INDEX_KEY;
+
+ /* FIXME, use a real flag for deciding about the key type */
+ if (root->fs_info->tree_root == root)
+ key_type = BTRFS_DIR_ITEM_KEY;
+ mutex_lock(&root->fs_info->fs_mutex);
+ key.objectid = inode->i_ino;
+ key.flags = 0;
+ btrfs_set_key_type(&key, key_type);
+ key.offset = filp->f_pos;
+ path = btrfs_alloc_path();
+ btrfs_init_path(path);
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto err;
+ advance = 0;
+ reada_leaves(root, path, inode->i_ino);
+ while(1) {
+ leaf = btrfs_buffer_leaf(path->nodes[0]);
+ nritems = btrfs_header_nritems(&leaf->header);
+ slot = path->slots[0];
+ if (advance || slot >= nritems) {
+ if (slot >= nritems -1) {
+ reada_leaves(root, path, inode->i_ino);
+ ret = btrfs_next_leaf(root, path);
+ if (ret)
+ break;
+ leaf = btrfs_buffer_leaf(path->nodes[0]);
+ nritems = btrfs_header_nritems(&leaf->header);
+ slot = path->slots[0];
+ } else {
+ slot++;
+ path->slots[0]++;
+ }
+ }
+ advance = 1;
+ item = leaf->items + slot;
+ if (btrfs_disk_key_objectid(&item->key) != key.objectid)
+ break;
+ if (btrfs_disk_key_type(&item->key) != key_type)
+ break;
+ if (btrfs_disk_key_offset(&item->key) < filp->f_pos)
+ continue;
+ filp->f_pos = btrfs_disk_key_offset(&item->key);
+ advance = 1;
+ di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
+ di_cur = 0;
+ di_total = btrfs_item_size(leaf->items + slot);
+ while(di_cur < di_total) {
+ d_type = btrfs_filetype_table[btrfs_dir_type(di)];
+ over = filldir(dirent, (const char *)(di + 1),
+ btrfs_dir_name_len(di),
+ btrfs_disk_key_offset(&item->key),
+ btrfs_disk_key_objectid(&di->location),
+ d_type);
+ if (over)
+ goto nopos;
+ di_len = btrfs_dir_name_len(di) + sizeof(*di);
+ di_cur += di_len;
+ di = (struct btrfs_dir_item *)((char *)di + di_len);
+ }
+ }
+ filp->f_pos++;
+nopos:
+ ret = 0;
+err:
+ btrfs_release_path(root, path);
+ btrfs_free_path(path);
+ mutex_unlock(&root->fs_info->fs_mutex);
+ return ret;
+}
+
+int btrfs_write_inode(struct inode *inode, int wait)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ int ret = 0;
+
+ if (wait) {
+ mutex_lock(&root->fs_info->fs_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, inode);
+ ret = btrfs_commit_transaction(trans, root);
+ mutex_unlock(&root->fs_info->fs_mutex);
+ }
+ return ret;
+}
+
+/*
+ * This is somewhat expense, updating the tree every time the
+ * inode changes. But, it is most likely to find the inode in cache.
+ * FIXME, needs more benchmarking...there are no reasons other than performance
+ * to keep or drop this code.
+ */
+void btrfs_dirty_inode(struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+
+ mutex_lock(&root->fs_info->fs_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, inode);
+ btrfs_update_inode(trans, root, inode);
+ btrfs_end_transaction(trans, root);
+ mutex_unlock(&root->fs_info->fs_mutex);
+ btrfs_btree_balance_dirty(root);
+}
+
+static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 objectid,
+ struct btrfs_block_group_cache *group,
+ int mode)
+{
+ struct inode *inode;
+ struct btrfs_inode_item inode_item;
+ struct btrfs_key *location;
+ int ret;
+ int owner;
+
+ inode = new_inode(root->fs_info->sb);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+
+ BTRFS_I(inode)->root = root;
+ if (mode & S_IFDIR)
+ owner = 0;
+ else
+ owner = 1;
+ group = btrfs_find_block_group(root, group, 0, 0, owner);
+ BTRFS_I(inode)->block_group = group;
+
+ inode->i_uid = current->fsuid;
+ inode->i_gid = current->fsgid;
+ inode->i_mode = mode;
+ inode->i_ino = objectid;
+ inode->i_blocks = 0;
+ inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
+ fill_inode_item(&inode_item, inode);
+ location = &BTRFS_I(inode)->location;
+ location->objectid = objectid;
+ location->flags = 0;
+ location->offset = 0;
+ btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
+
+ ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
+ BUG_ON(ret);
+
+ insert_inode_hash(inode);
+ return inode;
+}
+
+static inline u8 btrfs_inode_type(struct inode *inode)
+{
+ return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
+}
+
+static int btrfs_add_link(struct btrfs_trans_handle *trans,
+ struct dentry *dentry, struct inode *inode)
+{
+ int ret;
+ struct btrfs_key key;
+ struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
+ key.objectid = inode->i_ino;
+ key.flags = 0;
+ btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
+ key.offset = 0;
+
+ ret = btrfs_insert_dir_item(trans, root,
+ dentry->d_name.name, dentry->d_name.len,
+ dentry->d_parent->d_inode->i_ino,
+ &key, btrfs_inode_type(inode));
+ if (ret == 0) {
+ dentry->d_parent->d_inode->i_size += dentry->d_name.len * 2;
+ ret = btrfs_update_inode(trans, root,
+ dentry->d_parent->d_inode);
+ }
+ return ret;
+}
+
+static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
+ struct dentry *dentry, struct inode *inode)
+{
+ int err = btrfs_add_link(trans, dentry, inode);
+ if (!err) {
+ d_instantiate(dentry, inode);
+ return 0;
+ }
+ if (err > 0)
+ err = -EEXIST;
+ return err;
+}
+
+static int btrfs_create(struct inode *dir, struct dentry *dentry,
+ int mode, struct nameidata *nd)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct inode *inode;
+ int err;
+ int drop_inode = 0;
+ u64 objectid;
+
+ mutex_lock(&root->fs_info->fs_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, dir);
+
+ err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
+ if (err) {
+ err = -ENOSPC;
+ goto out_unlock;
+ }
+
+ inode = btrfs_new_inode(trans, root, objectid,
+ BTRFS_I(dir)->block_group, mode);
+ err = PTR_ERR(inode);
+ if (IS_ERR(inode))
+ goto out_unlock;
+
+ btrfs_set_trans_block_group(trans, inode);
+ err = btrfs_add_nondir(trans, dentry, inode);
+ if (err)
+ drop_inode = 1;
+ else {
+ inode->i_mapping->a_ops = &btrfs_aops;
+ inode->i_fop = &btrfs_file_operations;
+ inode->i_op = &btrfs_file_inode_operations;
+ }
+ dir->i_sb->s_dirt = 1;
+ btrfs_update_inode_block_group(trans, inode);
+ btrfs_update_inode_block_group(trans, dir);
+out_unlock:
+ btrfs_end_transaction(trans, root);
+ mutex_unlock(&root->fs_info->fs_mutex);
+
+ if (drop_inode) {
+ inode_dec_link_count(inode);
+ iput(inode);
+ }
+ btrfs_btree_balance_dirty(root);
+ return err;
+}
+
+static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
+ struct dentry *dentry)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct inode *inode = old_dentry->d_inode;
+ int err;
+ int drop_inode = 0;
+
+ if (inode->i_nlink == 0)
+ return -ENOENT;
+
+ inc_nlink(inode);
+ mutex_lock(&root->fs_info->fs_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, dir);
+ atomic_inc(&inode->i_count);
+ err = btrfs_add_nondir(trans, dentry, inode);
+ if (err)
+ drop_inode = 1;
+ dir->i_sb->s_dirt = 1;
+ btrfs_update_inode_block_group(trans, dir);
+ btrfs_update_inode(trans, root, inode);
+
+ btrfs_end_transaction(trans, root);
+ mutex_unlock(&root->fs_info->fs_mutex);
+
+ if (drop_inode) {
+ inode_dec_link_count(inode);
+ iput(inode);
+ }
+ btrfs_btree_balance_dirty(root);
+ return err;
+}
+
+static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 objectid, u64 dirid)
+{
+ int ret;
+ char buf[2];
+ struct btrfs_key key;
+
+ buf[0] = '.';
+ buf[1] = '.';
+
+ key.objectid = objectid;
+ key.offset = 0;
+ key.flags = 0;
+ btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
+
+ ret = btrfs_insert_dir_item(trans, root, buf, 1, objectid,
+ &key, BTRFS_FT_DIR);
+ if (ret)
+ goto error;
+ key.objectid = dirid;
+ ret = btrfs_insert_dir_item(trans, root, buf, 2, objectid,
+ &key, BTRFS_FT_DIR);
+ if (ret)
+ goto error;
+error:
+ return ret;
+}
+
+static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+ struct inode *inode;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ int err = 0;
+ int drop_on_err = 0;
+ u64 objectid;
+
+ mutex_lock(&root->fs_info->fs_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, dir);
+ if (IS_ERR(trans)) {
+ err = PTR_ERR(trans);
+ goto out_unlock;
+ }
+
+ err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
+ if (err) {
+ err = -ENOSPC;
+ goto out_unlock;
+ }
+
+ inode = btrfs_new_inode(trans, root, objectid,
+ BTRFS_I(dir)->block_group, S_IFDIR | mode);
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ goto out_fail;
+ }
+ drop_on_err = 1;
+ inode->i_op = &btrfs_dir_inode_operations;
+ inode->i_fop = &btrfs_dir_file_operations;
+ btrfs_set_trans_block_group(trans, inode);
+
+ err = btrfs_make_empty_dir(trans, root, inode->i_ino, dir->i_ino);
+ if (err)
+ goto out_fail;
+
+ inode->i_size = 6;
+ err = btrfs_update_inode(trans, root, inode);
+ if (err)
+ goto out_fail;
+ err = btrfs_add_link(trans, dentry, inode);
+ if (err)
+ goto out_fail;
+ d_instantiate(dentry, inode);
+ drop_on_err = 0;
+ dir->i_sb->s_dirt = 1;
+ btrfs_update_inode_block_group(trans, inode);
+ btrfs_update_inode_block_group(trans, dir);
+
+out_fail:
+ btrfs_end_transaction(trans, root);
+out_unlock:
+ mutex_unlock(&root->fs_info->fs_mutex);
+ if (drop_on_err)
+ iput(inode);
+ btrfs_btree_balance_dirty(root);
+ return err;
+}
+
+/*
+ * FIBMAP and others want to pass in a fake buffer head. They need to
+ * use BTRFS_GET_BLOCK_NO_DIRECT to make sure we don't try to memcpy
+ * any packed file data into the fake bh
+ */
+#define BTRFS_GET_BLOCK_NO_CREATE 0
+#define BTRFS_GET_BLOCK_CREATE 1
+#define BTRFS_GET_BLOCK_NO_DIRECT 2
+
+/*
+ * FIXME create==1 doe not work.
+ */
+static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
+ struct buffer_head *result, int create)
+{
+ int ret;
+ int err = 0;
+ u64 blocknr;
+ u64 extent_start = 0;
+ u64 extent_end = 0;
+ u64 objectid = inode->i_ino;
+ u32 found_type;
+ u64 alloc_hint = 0;
+ struct btrfs_path *path;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_file_extent_item *item;
+ struct btrfs_leaf *leaf;
+ struct btrfs_disk_key *found_key;
+ struct btrfs_trans_handle *trans = NULL;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ btrfs_init_path(path);
+ if (create & BTRFS_GET_BLOCK_CREATE) {
+ WARN_ON(1);
+ /* this almost but not quite works */
+ trans = btrfs_start_transaction(root, 1);
+ if (!trans) {
+ err = -ENOMEM;
+ goto out;
+ }
+ ret = btrfs_drop_extents(trans, root, inode,
+ iblock << inode->i_blkbits,
+ (iblock + 1) << inode->i_blkbits,
+ &alloc_hint);
+ BUG_ON(ret);
+ }
+
+ ret = btrfs_lookup_file_extent(NULL, root, path,
+ inode->i_ino,
+ iblock << inode->i_blkbits, 0);
+ if (ret < 0) {
+ err = ret;
+ goto out;
+ }
+
+ if (ret != 0) {
+ if (path->slots[0] == 0) {
+ btrfs_release_path(root, path);
+ goto not_found;
+ }
+ path->slots[0]--;
+ }
+
+ item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
+ struct btrfs_file_extent_item);
+ leaf = btrfs_buffer_leaf(path->nodes[0]);
+ blocknr = btrfs_file_extent_disk_blocknr(item);
+ blocknr += btrfs_file_extent_offset(item);
+
+ /* are we inside the extent that was found? */
+ found_key = &leaf->items[path->slots[0]].key;
+ found_type = btrfs_disk_key_type(found_key);
+ if (btrfs_disk_key_objectid(found_key) != objectid ||
+ found_type != BTRFS_EXTENT_DATA_KEY) {
+ extent_end = 0;
+ extent_start = 0;
+ goto not_found;
+ }
+ found_type = btrfs_file_extent_type(item);
+ extent_start = btrfs_disk_key_offset(&leaf->items[path->slots[0]].key);
+ if (found_type == BTRFS_FILE_EXTENT_REG) {
+ extent_start = extent_start >> inode->i_blkbits;
+ extent_end = extent_start + btrfs_file_extent_num_blocks(item);
+ err = 0;
+ if (btrfs_file_extent_disk_blocknr(item) == 0)
+ goto out;
+ if (iblock >= extent_start && iblock < extent_end) {
+ btrfs_map_bh_to_logical(root, result, blocknr +
+ iblock - extent_start);
+ goto out;
+ }
+ } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
+ char *ptr;
+ char *map;
+ u32 size;
+
+ if (create & BTRFS_GET_BLOCK_NO_DIRECT) {
+ err = -EINVAL;
+ goto out;
+ }
+ size = btrfs_file_extent_inline_len(leaf->items +
+ path->slots[0]);
+ extent_end = (extent_start + size) >> inode->i_blkbits;
+ extent_start >>= inode->i_blkbits;
+ if (iblock < extent_start || iblock > extent_end) {
+ goto not_found;
+ }
+ ptr = btrfs_file_extent_inline_start(item);
+ map = kmap(result->b_page);
+ memcpy(map, ptr, size);
+ memset(map + size, 0, PAGE_CACHE_SIZE - size);
+ flush_dcache_page(result->b_page);
+ kunmap(result->b_page);
+ set_buffer_uptodate(result);
+ SetPageChecked(result->b_page);
+ btrfs_map_bh_to_logical(root, result, 0);
+ }
+not_found:
+ if (create & BTRFS_GET_BLOCK_CREATE) {
+ struct btrfs_key ins;
+ ret = btrfs_alloc_extent(trans, root, inode->i_ino,
+ 1, alloc_hint, (u64)-1,
+ &ins, 1);
+ BUG_ON(ret);
+ ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
+ iblock << inode->i_blkbits,
+ ins.objectid, ins.offset,
+ ins.offset);
+ BUG_ON(ret);
+ SetPageChecked(result->b_page);
+ btrfs_map_bh_to_logical(root, result, ins.objectid);
+ }
+out:
+ if (trans)
+ err = btrfs_end_transaction(trans, root);
+ btrfs_free_path(path);
+ return err;
+}
+
+int btrfs_get_block(struct inode *inode, sector_t iblock,
+ struct buffer_head *result, int create)
+{
+ int err;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ mutex_lock(&root->fs_info->fs_mutex);
+ err = btrfs_get_block_lock(inode, iblock, result, create);
+ mutex_unlock(&root->fs_info->fs_mutex);
+ return err;
+}
+
+static int btrfs_get_block_bmap(struct inode *inode, sector_t iblock,
+ struct buffer_head *result, int create)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ mutex_lock(&root->fs_info->fs_mutex);
+ btrfs_get_block_lock(inode, iblock, result, BTRFS_GET_BLOCK_NO_DIRECT);
+ mutex_unlock(&root->fs_info->fs_mutex);
+ return 0;
+}
+
+static sector_t btrfs_bmap(struct address_space *as, sector_t block)
+{
+ return generic_block_bmap(as, block, btrfs_get_block_bmap);
+}
+
+static int btrfs_prepare_write(struct file *file, struct page *page,
+ unsigned from, unsigned to)
+{
+ return block_prepare_write(page, from, to, btrfs_get_block);
+}
+
+static int btrfs_readpage(struct file *file, struct page *page)
+{
+ return mpage_readpage(page, btrfs_get_block);
+}
+
+/*
+ * Aside from a tiny bit of packed file data handling, this is the
+ * same as the generic code.
+ *
+ * While block_write_full_page is writing back the dirty buffers under
+ * the page lock, whoever dirtied the buffers may decide to clean them
+ * again at any time. We handle that by only looking at the buffer
+ * state inside lock_buffer().
+ *
+ * If block_write_full_page() is called for regular writeback
+ * (wbc->sync_mode == WB_SYNC_NONE) then it will redirty a page which has a
+ * locked buffer. This only can happen if someone has written the buffer
+ * directly, with submit_bh(). At the address_space level PageWriteback
+ * prevents this contention from occurring.
+ */
+static int __btrfs_write_full_page(struct inode *inode, struct page *page,
+ struct writeback_control *wbc)
+{
+ int err;
+ sector_t block;
+ sector_t last_block;
+ struct buffer_head *bh, *head;
+ const unsigned blocksize = 1 << inode->i_blkbits;
+ int nr_underway = 0;
+
+ BUG_ON(!PageLocked(page));
+
+ last_block = (i_size_read(inode) - 1) >> inode->i_blkbits;
+
+ if (!page_has_buffers(page)) {
+ create_empty_buffers(page, blocksize,
+ (1 << BH_Dirty)|(1 << BH_Uptodate));
+ }
+
+ /*
+ * Be very careful. We have no exclusion from __set_page_dirty_buffers
+ * here, and the (potentially unmapped) buffers may become dirty at
+ * any time. If a buffer becomes dirty here after we've inspected it
+ * then we just miss that fact, and the page stays dirty.
+ *
+ * Buffers outside i_size may be dirtied by __set_page_dirty_buffers;
+ * handle that here by just cleaning them.
+ */
+
+ block = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
+ head = page_buffers(page);
+ bh = head;
+
+ /*
+ * Get all the dirty buffers mapped to disk addresses and
+ * handle any aliases from the underlying blockdev's mapping.
+ */
+ do {
+ if (block > last_block) {
+ /*
+ * mapped buffers outside i_size will occur, because
+ * this page can be outside i_size when there is a
+ * truncate in progress.
+ */
+ /*
+ * The buffer was zeroed by block_write_full_page()
+ */
+ clear_buffer_dirty(bh);
+ set_buffer_uptodate(bh);
+ } else if (!buffer_mapped(bh) && buffer_dirty(bh)) {
+ WARN_ON(bh->b_size != blocksize);
+ err = btrfs_get_block(inode, block, bh, 0);
+ if (err) {
+ goto recover;
+ }
+ if (buffer_new(bh)) {
+ /* blockdev mappings never come here */
+ clear_buffer_new(bh);
+ }
+ }
+ bh = bh->b_this_page;
+ block++;
+ } while (bh != head);
+
+ do {
+ if (!buffer_mapped(bh))
+ continue;
+ /*
+ * If it's a fully non-blocking write attempt and we cannot
+ * lock the buffer then redirty the page. Note that this can
+ * potentially cause a busy-wait loop from pdflush and kswapd
+ * activity, but those code paths have their own higher-level
+ * throttling.
+ */
+ if (wbc->sync_mode != WB_SYNC_NONE || !wbc->nonblocking) {
+ lock_buffer(bh);
+ } else if (test_set_buffer_locked(bh)) {
+ redirty_page_for_writepage(wbc, page);
+ continue;
+ }
+ if (test_clear_buffer_dirty(bh) && bh->b_blocknr != 0) {
+ mark_buffer_async_write(bh);
+ } else {
+ unlock_buffer(bh);
+ }
+ } while ((bh = bh->b_this_page) != head);
+
+ /*
+ * The page and its buffers are protected by PageWriteback(), so we can
+ * drop the bh refcounts early.
+ */
+ BUG_ON(PageWriteback(page));
+ set_page_writeback(page);
+
+ do {
+ struct buffer_head *next = bh->b_this_page;
+ if (buffer_async_write(bh)) {
+ submit_bh(WRITE, bh);
+ nr_underway++;
+ }
+ bh = next;
+ } while (bh != head);
+ unlock_page(page);
+
+ err = 0;
+done:
+ if (nr_underway == 0) {
+ /*
+ * The page was marked dirty, but the buffers were
+ * clean. Someone wrote them back by hand with
+ * ll_rw_block/submit_bh. A rare case.
+ */
+ int uptodate = 1;
+ do {
+ if (!buffer_uptodate(bh)) {
+ uptodate = 0;
+ break;
+ }
+ bh = bh->b_this_page;
+ } while (bh != head);
+ if (uptodate)
+ SetPageUptodate(page);
+ end_page_writeback(page);
+ }
+ return err;
+
+recover:
+ /*
+ * ENOSPC, or some other error. We may already have added some
+ * blocks to the file, so we need to write these out to avoid
+ * exposing stale data.
+ * The page is currently locked and not marked for writeback
+ */
+ bh = head;
+ /* Recovery: lock and submit the mapped buffers */
+ do {
+ if (buffer_mapped(bh) && buffer_dirty(bh)) {
+ lock_buffer(bh);
+ mark_buffer_async_write(bh);
+ } else {
+ /*
+ * The buffer may have been set dirty during
+ * attachment to a dirty page.
+ */
+ clear_buffer_dirty(bh);
+ }
+ } while ((bh = bh->b_this_page) != head);
+ SetPageError(page);
+ BUG_ON(PageWriteback(page));
+ set_page_writeback(page);
+ do {
+ struct buffer_head *next = bh->b_this_page;
+ if (buffer_async_write(bh)) {
+ clear_buffer_dirty(bh);
+ submit_bh(WRITE, bh);
+ nr_underway++;
+ }
+ bh = next;
+ } while (bh != head);
+ unlock_page(page);
+ goto done;
+}
+
+static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
+{
+ struct inode * const inode = page->mapping->host;
+ loff_t i_size = i_size_read(inode);
+ const pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
+ unsigned offset;
+ void *kaddr;
+
+ /* Is the page fully inside i_size? */
+ if (page->index < end_index)
+ return __btrfs_write_full_page(inode, page, wbc);
+
+ /* Is the page fully outside i_size? (truncate in progress) */
+ offset = i_size & (PAGE_CACHE_SIZE-1);
+ if (page->index >= end_index+1 || !offset) {
+ /*
+ * The page may have dirty, unmapped buffers. For example,
+ * they may have been added in ext3_writepage(). Make them
+ * freeable here, so the page does not leak.
+ */
+ block_invalidatepage(page, 0);
+ unlock_page(page);
+ return 0; /* don't care */
+ }
+
+ /*
+ * The page straddles i_size. It must be zeroed out on each and every
+ * writepage invokation because it may be mmapped. "A file is mapped
+ * in multiples of the page size. For a file that is not a multiple of
+ * the page size, the remaining memory is zeroed when mapped, and
+ * writes to that region are not written out to the file."
+ */
+ kaddr = kmap_atomic(page, KM_USER0);
+ memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr, KM_USER0);
+ return __btrfs_write_full_page(inode, page, wbc);
+}
+
+static void btrfs_truncate(struct inode *inode)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret;
+ struct btrfs_trans_handle *trans;
+
+ if (!S_ISREG(inode->i_mode))
+ return;
+ if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+ return;
+
+ btrfs_truncate_page(inode->i_mapping, inode->i_size);
+
+ mutex_lock(&root->fs_info->fs_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, inode);
+
+ /* FIXME, add redo link to tree so we don't leak on crash */
+ ret = btrfs_truncate_in_trans(trans, root, inode);
+ BUG_ON(ret);
+ btrfs_update_inode(trans, root, inode);
+ ret = btrfs_end_transaction(trans, root);
+ BUG_ON(ret);
+ mutex_unlock(&root->fs_info->fs_mutex);
+ btrfs_btree_balance_dirty(root);
+}
+
+int btrfs_commit_write(struct file *file, struct page *page,
+ unsigned from, unsigned to)
+{
+ struct inode *inode = page->mapping->host;
+ struct buffer_head *bh;
+ loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
+
+ SetPageUptodate(page);
+ bh = page_buffers(page);
+ set_buffer_uptodate(bh);
+ if (buffer_mapped(bh) && bh->b_blocknr != 0) {
+ set_page_dirty(page);
+ }
+ if (pos > inode->i_size) {
+ i_size_write(inode, pos);
+ mark_inode_dirty(inode);
+ }
+ return 0;
+}
+
+static int create_subvol(struct btrfs_root *root, char *name, int namelen)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_key key;
+ struct btrfs_root_item root_item;
+ struct btrfs_inode_item *inode_item;
+ struct buffer_head *subvol;
+ struct btrfs_leaf *leaf;
+ struct btrfs_root *new_root;
+ struct inode *inode;
+ struct inode *dir;
+ int ret;
+ u64 objectid;
+ u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
+
+ mutex_lock(&root->fs_info->fs_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ BUG_ON(!trans);
+
+ subvol = btrfs_alloc_free_block(trans, root, 0);
+ if (subvol == NULL)
+ return -ENOSPC;
+ leaf = btrfs_buffer_leaf(subvol);
+ btrfs_set_header_nritems(&leaf->header, 0);
+ btrfs_set_header_level(&leaf->header, 0);
+ btrfs_set_header_blocknr(&leaf->header, bh_blocknr(subvol));
+ btrfs_set_header_generation(&leaf->header, trans->transid);
+ btrfs_set_header_owner(&leaf->header, root->root_key.objectid);
+ memcpy(leaf->header.fsid, root->fs_info->disk_super->fsid,
+ sizeof(leaf->header.fsid));
+ mark_buffer_dirty(subvol);
+
+ inode_item = &root_item.inode;
+ memset(inode_item, 0, sizeof(*inode_item));
+ btrfs_set_inode_generation(inode_item, 1);
+ btrfs_set_inode_size(inode_item, 3);
+ btrfs_set_inode_nlink(inode_item, 1);
+ btrfs_set_inode_nblocks(inode_item, 1);
+ btrfs_set_inode_mode(inode_item, S_IFDIR | 0755);
+
+ btrfs_set_root_blocknr(&root_item, bh_blocknr(subvol));
+ btrfs_set_root_refs(&root_item, 1);
+ brelse(subvol);
+ subvol = NULL;
+
+ ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
+ 0, &objectid);
+ BUG_ON(ret);
+
+ btrfs_set_root_dirid(&root_item, new_dirid);
+
+ key.objectid = objectid;
+ key.offset = 1;
+ key.flags = 0;
+ btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
+ ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
+ &root_item);
+ BUG_ON(ret);
+
+ /*
+ * insert the directory item
+ */
+ key.offset = (u64)-1;
+ dir = root->fs_info->sb->s_root->d_inode;
+ ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
+ name, namelen, dir->i_ino, &key,
+ BTRFS_FT_DIR);
+ BUG_ON(ret);
+
+ ret = btrfs_commit_transaction(trans, root);
+ BUG_ON(ret);
+
+ new_root = btrfs_read_fs_root(root->fs_info, &key);
+ BUG_ON(!new_root);
+
+ trans = btrfs_start_transaction(new_root, 1);
+ BUG_ON(!trans);
+
+ inode = btrfs_new_inode(trans, new_root, new_dirid,
+ BTRFS_I(dir)->block_group, S_IFDIR | 0700);
+ inode->i_op = &btrfs_dir_inode_operations;
+ inode->i_fop = &btrfs_dir_file_operations;
+
+ ret = btrfs_make_empty_dir(trans, new_root, new_dirid, new_dirid);
+ BUG_ON(ret);
+
+ inode->i_nlink = 1;
+ inode->i_size = 6;
+ ret = btrfs_update_inode(trans, new_root, inode);
+ BUG_ON(ret);
+
+ ret = btrfs_commit_transaction(trans, new_root);
+ BUG_ON(ret);
+
+ iput(inode);
+
+ mutex_unlock(&root->fs_info->fs_mutex);
+ btrfs_btree_balance_dirty(root);
+ return 0;
+}
+
+static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_key key;
+ struct btrfs_root_item new_root_item;
+ int ret;
+ u64 objectid;
+
+ if (!root->ref_cows)
+ return -EINVAL;
+
+ mutex_lock(&root->fs_info->fs_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ BUG_ON(!trans);
+
+ ret = btrfs_update_inode(trans, root, root->inode);
+ BUG_ON(ret);
+
+ ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
+ 0, &objectid);
+ BUG_ON(ret);
+
+ memcpy(&new_root_item, &root->root_item,
+ sizeof(new_root_item));
+
+ key.objectid = objectid;
+ key.offset = 1;
+ key.flags = 0;
+ btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
+ btrfs_set_root_blocknr(&new_root_item, bh_blocknr(root->node));
+
+ ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
+ &new_root_item);
+ BUG_ON(ret);
+
+ /*
+ * insert the directory item
+ */
+ key.offset = (u64)-1;
+ ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
+ name, namelen,
+ root->fs_info->sb->s_root->d_inode->i_ino,
+ &key, BTRFS_FT_DIR);
+
+ BUG_ON(ret);
+
+ ret = btrfs_inc_root_ref(trans, root);
+ BUG_ON(ret);
+
+ ret = btrfs_commit_transaction(trans, root);
+ BUG_ON(ret);
+ mutex_unlock(&root->fs_info->fs_mutex);
+ btrfs_btree_balance_dirty(root);
+ return 0;
+}
+
+int btrfs_ioctl(struct inode *inode, struct file *filp, unsigned int
+ cmd, unsigned long arg)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_ioctl_vol_args vol_args;
+ int ret = 0;
+ struct btrfs_dir_item *di;
+ int namelen;
+ struct btrfs_path *path;
+ u64 root_dirid;
+
+ switch (cmd) {
+ case BTRFS_IOC_SNAP_CREATE:
+ if (copy_from_user(&vol_args,
+ (struct btrfs_ioctl_vol_args __user *)arg,
+ sizeof(vol_args)))
+ return -EFAULT;
+ namelen = strlen(vol_args.name);
+ if (namelen > BTRFS_VOL_NAME_MAX)
+ return -EINVAL;
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+ root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
+ mutex_lock(&root->fs_info->fs_mutex);
+ di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
+ path, root_dirid,
+ vol_args.name, namelen, 0);
+ mutex_unlock(&root->fs_info->fs_mutex);
+ btrfs_free_path(path);
+ if (di && !IS_ERR(di))
+ return -EEXIST;
+
+ if (root == root->fs_info->tree_root)
+ ret = create_subvol(root, vol_args.name, namelen);
+ else
+ ret = create_snapshot(root, vol_args.name, namelen);
+ WARN_ON(ret);
+ break;
+ default:
+ return -ENOTTY;
+ }
+ return ret;
+}
+
+#ifdef CONFIG_COMPAT
+long btrfs_compat_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ struct inode *inode = file->f_path.dentry->d_inode;
+ int ret;
+ lock_kernel();
+ ret = btrfs_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
+ unlock_kernel();
+ return ret;
+
+}
+#endif
+
+/*
+ * Called inside transaction, so use GFP_NOFS
+ */
+struct inode *btrfs_alloc_inode(struct super_block *sb)
+{
+ struct btrfs_inode *ei;
+
+ ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
+ if (!ei)
+ return NULL;
+ return &ei->vfs_inode;
+}
+
+void btrfs_destroy_inode(struct inode *inode)
+{
+ WARN_ON(!list_empty(&inode->i_dentry));
+ WARN_ON(inode->i_data.nrpages);
+
+ kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
+}
+
+static void init_once(void * foo, struct kmem_cache * cachep,
+ unsigned long flags)
+{
+ struct btrfs_inode *ei = (struct btrfs_inode *) foo;
+
+ inode_init_once(&ei->vfs_inode);
+}
+
+void btrfs_destroy_cachep(void)
+{
+ if (btrfs_inode_cachep)
+ kmem_cache_destroy(btrfs_inode_cachep);
+ if (btrfs_trans_handle_cachep)
+ kmem_cache_destroy(btrfs_trans_handle_cachep);
+ if (btrfs_transaction_cachep)
+ kmem_cache_destroy(btrfs_transaction_cachep);
+ if (btrfs_bit_radix_cachep)
+ kmem_cache_destroy(btrfs_bit_radix_cachep);
+ if (btrfs_path_cachep)
+ kmem_cache_destroy(btrfs_path_cachep);
+}
+
+int btrfs_init_cachep(void)
+{
+ btrfs_inode_cachep = kmem_cache_create("btrfs_inode_cache",
+ sizeof(struct btrfs_inode),
+ 0, (SLAB_RECLAIM_ACCOUNT|
+ SLAB_MEM_SPREAD),
+ init_once, NULL);
+ if (!btrfs_inode_cachep)
+ goto fail;
+ btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle_cache",
+ sizeof(struct btrfs_trans_handle),
+ 0, (SLAB_RECLAIM_ACCOUNT|
+ SLAB_MEM_SPREAD),
+ NULL, NULL);
+ if (!btrfs_trans_handle_cachep)
+ goto fail;
+ btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction_cache",
+ sizeof(struct btrfs_transaction),
+ 0, (SLAB_RECLAIM_ACCOUNT|
+ SLAB_MEM_SPREAD),
+ NULL, NULL);
+ if (!btrfs_transaction_cachep)
+ goto fail;
+ btrfs_path_cachep = kmem_cache_create("btrfs_path_cache",
+ sizeof(struct btrfs_transaction),
+ 0, (SLAB_RECLAIM_ACCOUNT|
+ SLAB_MEM_SPREAD),
+ NULL, NULL);
+ if (!btrfs_path_cachep)
+ goto fail;
+ btrfs_bit_radix_cachep = kmem_cache_create("btrfs_radix",
+ 256,
+ 0, (SLAB_RECLAIM_ACCOUNT|
+ SLAB_MEM_SPREAD |
+ SLAB_DESTROY_BY_RCU),
+ NULL, NULL);
+ if (!btrfs_bit_radix_cachep)
+ goto fail;
+ return 0;
+fail:
+ btrfs_destroy_cachep();
+ return -ENOMEM;
+}
+
+static int btrfs_getattr(struct vfsmount *mnt,
+ struct dentry *dentry, struct kstat *stat)
+{
+ struct inode *inode = dentry->d_inode;
+ generic_fillattr(inode, stat);
+ stat->blksize = 256 * 1024;
+ return 0;
+}
+
+static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
+ struct inode * new_dir,struct dentry *new_dentry)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(old_dir)->root;
+ struct inode *new_inode = new_dentry->d_inode;
+ struct inode *old_inode = old_dentry->d_inode;
+ struct timespec ctime = CURRENT_TIME;
+ struct btrfs_path *path;
+ struct btrfs_dir_item *di;
+ int ret;
+
+ if (S_ISDIR(old_inode->i_mode) && new_inode &&
+ new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
+ return -ENOTEMPTY;
+ }
+ mutex_lock(&root->fs_info->fs_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, new_dir);
+ path = btrfs_alloc_path();
+ if (!path) {
+ ret = -ENOMEM;
+ goto out_fail;
+ }
+
+ old_dentry->d_inode->i_nlink++;
+ old_dir->i_ctime = old_dir->i_mtime = ctime;
+ new_dir->i_ctime = new_dir->i_mtime = ctime;
+ old_inode->i_ctime = ctime;
+ if (S_ISDIR(old_inode->i_mode) && old_dir != new_dir) {
+ struct btrfs_key *location = &BTRFS_I(new_dir)->location;
+ u64 old_parent_oid;
+ di = btrfs_lookup_dir_item(trans, root, path, old_inode->i_ino,
+ "..", 2, -1);
+ if (IS_ERR(di)) {
+ ret = PTR_ERR(di);
+ goto out_fail;
+ }
+ if (!di) {
+ ret = -ENOENT;
+ goto out_fail;
+ }
+ old_parent_oid = btrfs_disk_key_objectid(&di->location);
+ ret = btrfs_del_item(trans, root, path);
+ if (ret) {
+ ret = -EIO;
+ goto out_fail;
+ }
+ btrfs_release_path(root, path);
+
+ di = btrfs_lookup_dir_index_item(trans, root, path,
+ old_inode->i_ino,
+ old_parent_oid,
+ "..", 2, -1);
+ if (IS_ERR(di)) {
+ ret = PTR_ERR(di);
+ goto out_fail;
+ }
+ if (!di) {
+ ret = -ENOENT;
+ goto out_fail;
+ }
+ ret = btrfs_del_item(trans, root, path);
+ if (ret) {
+ ret = -EIO;
+ goto out_fail;
+ }
+ btrfs_release_path(root, path);
+
+ ret = btrfs_insert_dir_item(trans, root, "..", 2,
+ old_inode->i_ino, location,
+ BTRFS_FT_DIR);
+ if (ret)
+ goto out_fail;
+ }
+
+
+ ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
+ if (ret)
+ goto out_fail;
+
+ if (new_inode) {
+ new_inode->i_ctime = CURRENT_TIME;
+ ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
+ if (ret)
+ goto out_fail;
+ if (S_ISDIR(new_inode->i_mode))
+ clear_nlink(new_inode);
+ else
+ drop_nlink(new_inode);
+ btrfs_update_inode(trans, root, new_inode);
+ }
+ ret = btrfs_add_link(trans, new_dentry, old_inode);
+ if (ret)
+ goto out_fail;
+
+out_fail:
+ btrfs_free_path(path);
+ btrfs_end_transaction(trans, root);
+ mutex_unlock(&root->fs_info->fs_mutex);
+ return ret;
+}
+
+static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
+ const char *symname)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct inode *inode;
+ int err;
+ int drop_inode = 0;
+ u64 objectid;
+ int name_len;
+ int datasize;
+ char *ptr;
+ struct btrfs_file_extent_item *ei;
+
+ name_len = strlen(symname) + 1;
+ if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
+ return -ENAMETOOLONG;
+ mutex_lock(&root->fs_info->fs_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ btrfs_set_trans_block_group(trans, dir);
+
+ err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
+ if (err) {
+ err = -ENOSPC;
+ goto out_unlock;
+ }
+
+ inode = btrfs_new_inode(trans, root, objectid,
+ BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
+ err = PTR_ERR(inode);
+ if (IS_ERR(inode))
+ goto out_unlock;
+
+ btrfs_set_trans_block_group(trans, inode);
+ err = btrfs_add_nondir(trans, dentry, inode);
+ if (err)
+ drop_inode = 1;
+ else {
+ inode->i_mapping->a_ops = &btrfs_aops;
+ inode->i_fop = &btrfs_file_operations;
+ inode->i_op = &btrfs_file_inode_operations;
+ }
+ dir->i_sb->s_dirt = 1;
+ btrfs_update_inode_block_group(trans, inode);
+ btrfs_update_inode_block_group(trans, dir);
+ if (drop_inode)
+ goto out_unlock;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ key.objectid = inode->i_ino;
+ key.offset = 0;
+ key.flags = 0;
+ btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
+ datasize = btrfs_file_extent_calc_inline_size(name_len);
+ err = btrfs_insert_empty_item(trans, root, path, &key,
+ datasize);
+ BUG_ON(err);
+ ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
+ path->slots[0], struct btrfs_file_extent_item);
+ btrfs_set_file_extent_generation(ei, trans->transid);
+ btrfs_set_file_extent_type(ei,
+ BTRFS_FILE_EXTENT_INLINE);
+ ptr = btrfs_file_extent_inline_start(ei);
+ btrfs_memcpy(root, path->nodes[0]->b_data,
+ ptr, symname, name_len);
+ mark_buffer_dirty(path->nodes[0]);
+ btrfs_free_path(path);
+ inode->i_op = &btrfs_symlink_inode_operations;
+ inode->i_mapping->a_ops = &btrfs_symlink_aops;
+ inode->i_size = name_len - 1;
+ btrfs_update_inode(trans, root, inode);
+ err = 0;
+
+out_unlock:
+ btrfs_end_transaction(trans, root);
+ mutex_unlock(&root->fs_info->fs_mutex);
+
+ if (drop_inode) {
+ inode_dec_link_count(inode);
+ iput(inode);
+ }
+ btrfs_btree_balance_dirty(root);
+ return err;
+}
+
+static struct inode_operations btrfs_dir_inode_operations = {
+ .lookup = btrfs_lookup,
+ .create = btrfs_create,
+ .unlink = btrfs_unlink,
+ .link = btrfs_link,
+ .mkdir = btrfs_mkdir,
+ .rmdir = btrfs_rmdir,
+ .rename = btrfs_rename,
+ .symlink = btrfs_symlink,
+ .setattr = btrfs_setattr,
+};
+
+static struct inode_operations btrfs_dir_ro_inode_operations = {
+ .lookup = btrfs_lookup,
+};
+
+static struct file_operations btrfs_dir_file_operations = {
+ .llseek = generic_file_llseek,
+ .read = generic_read_dir,
+ .readdir = btrfs_readdir,
+ .ioctl = btrfs_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = btrfs_compat_ioctl,
+#endif
+};
+
+static struct address_space_operations btrfs_aops = {
+ .readpage = btrfs_readpage,
+ .writepage = btrfs_writepage,
+ .sync_page = block_sync_page,
+ .prepare_write = btrfs_prepare_write,
+ .commit_write = btrfs_commit_write,
+ .bmap = btrfs_bmap,
+};
+
+static struct address_space_operations btrfs_symlink_aops = {
+ .readpage = btrfs_readpage,
+ .writepage = btrfs_writepage,
+};
+
+static struct inode_operations btrfs_file_inode_operations = {
+ .truncate = btrfs_truncate,
+ .getattr = btrfs_getattr,
+ .setattr = btrfs_setattr,
+};
+
+static struct inode_operations btrfs_symlink_inode_operations = {
+ .readlink = generic_readlink,
+ .follow_link = page_follow_link_light,
+ .put_link = page_put_link,
+};