Hi,
On Thu, Jun 16, 2011 at 05:41:10PM +0800, Liu Bo wrote:
> --- a/fs/btrfs/btrfs_inode.h
> +++ b/fs/btrfs/btrfs_inode.h
> @@ -29,11 +29,6 @@ struct btrfs_inode {
> /* which subvolume this inode belongs to */
> struct btrfs_root *root;
>
> - /* key used to find this inode on disk. This is used by the code
> - * to read in roots of subvolumes
> - */
> - struct btrfs_key location;
> -
> /* the extent_tree has caches of all the extent mappings to disk */
> struct extent_map_tree extent_tree;
>
> @@ -72,6 +67,9 @@ struct btrfs_inode {
> /* the space_info for where this inode's data allocations are done */
> struct btrfs_space_info *space_info;
>
> + /* full 64 bit inode number */
> + u64 inode_id;
I like this optimization! It saves 16 bytes (7 for padding after
locatioin and 1+8 for the removed key type and offset). However I'd
rather see this named 'ino' or 'i_ino', it's a more common name for
inode number.
> +
> /* full 64 bit generation number, struct vfs_inode doesn't have a big
> * enough field for this.
> */
> @@ -171,7 +169,7 @@ static inline struct btrfs_inode *BTRFS_I(struct inode *inode)
>
> static inline u64 btrfs_ino(struct inode *inode)
> {
> - u64 ino = BTRFS_I(inode)->location.objectid;
> + u64 ino = BTRFS_I(inode)->inode_id;
see? :)
>
> if (ino <= BTRFS_FIRST_FREE_OBJECTID)
> ino = inode->i_ino;
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index a203d36..5d6bbb9 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -1693,9 +1693,8 @@ struct btrfs_root *open_ctree(struct super_block *sb,
>
> BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
>
> + BTRFS_I(fs_info->btree_inode)->inode_id = BTRFS_BTREE_INODE_OBJECTID;
> BTRFS_I(fs_info->btree_inode)->root = tree_root;
> - memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
> - sizeof(struct btrfs_key));
> BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
> insert_inode_hash(fs_info->btree_inode);
>
> diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c
> index 1b8dc33..cdd3a84 100644
> --- a/fs/btrfs/export.c
> +++ b/fs/btrfs/export.c
> @@ -43,7 +43,7 @@ static int btrfs_encode_fh(struct dentry *dentry, u32 *fh, int *max_len,
> spin_lock(&dentry->d_lock);
>
> parent = dentry->d_parent->d_inode;
> - fid->parent_objectid = BTRFS_I(parent)->location.objectid;
> + fid->parent_objectid = btrfs_ino(parent);
is there a reason to do btrfs_ino here instead of simple
BTRFS_I(parent)->inode_id ? Although there is just one more conditional
test whether i_ino is <= BTRFS_FREE_INO_OBJECTID, which would not hurt
so much, using btrfs_ino says this is to be expected and has a different
meaning than the original code.
The changes are not consistent, you add btrfs_ino where was a memcpy in
the original code but not everywhere:
> fid->parent_gen = parent->i_generation;
> parent_root_id = BTRFS_I(parent)->root->objectid;
>
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index 5b9b6b6..3a1f8ee 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -3037,7 +3037,7 @@ int btrfs_check_data_free_space(struct inode *inode, u64 bytes)
> bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
>
> if (root == root->fs_info->tree_root ||
> - BTRFS_I(inode)->location.objectid == BTRFS_FREE_INO_OBJECTID) {
> + BTRFS_I(inode)->inode_id == BTRFS_FREE_INO_OBJECTID) {
> alloc_chunk = 0;
> committed = 1;
> }
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index 02ff4a1..e01a084 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -754,7 +754,7 @@ static inline bool is_free_space_inode(struct btrfs_root *root,
> struct inode *inode)
> {
> if (root == root->fs_info->tree_root ||
> - BTRFS_I(inode)->location.objectid == BTRFS_FREE_INO_OBJECTID)
> + BTRFS_I(inode)->inode_id == BTRFS_FREE_INO_OBJECTID)
> return true;
> return false;
> }
> @@ -2513,7 +2513,10 @@ static void btrfs_read_locked_inode(struct inode *inode)
> path = btrfs_alloc_path();
> BUG_ON(!path);
> path->leave_spinning = 1;
> - memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
> +
> + location.objectid = btrfs_ino(inode);
> + location.offset = 0;
> + btrfs_set_key_type(&location, BTRFS_INODE_ITEM_KEY);
memcpy -> btrfs_ino
>
> ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
> if (ret)
> @@ -2667,6 +2670,7 @@ noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
> struct btrfs_inode_item *inode_item;
> struct btrfs_path *path;
> struct extent_buffer *leaf;
> + struct btrfs_key location;
> int ret;
>
> /*
> @@ -2687,8 +2691,12 @@ noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
> return -ENOMEM;
>
> path->leave_spinning = 1;
> - ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
> - 1);
> +
> + location.objectid = btrfs_ino(inode);
not sure about this, but I assume location.objectid will never be
<= FIRST_FREE_OBJECT_ID and btrfs_ino will return
BTRFS_I->location.objectid anyway. (there are more occurences of this
pattern)
> + location.offset = 0;
> + btrfs_set_key_type(&location, BTRFS_INODE_ITEM_KEY);
> +
> + ret = btrfs_lookup_inode(trans, root, path, &location, 1);
> if (ret) {
> if (ret > 0)
> ret = -ENOENT;
> @@ -2839,6 +2847,7 @@ static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
> struct btrfs_path *path;
> struct btrfs_inode_ref *ref;
> struct btrfs_dir_item *di;
> + struct btrfs_key location;
> struct inode *inode = dentry->d_inode;
> u64 index;
> int check_link = 1;
> @@ -2880,8 +2889,11 @@ static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
> path->skip_locking = 1;
> path->search_commit_root = 1;
>
> - ret = btrfs_lookup_inode(trans, root, path,
> - &BTRFS_I(dir)->location, 0);
> + location.objectid = btrfs_ino(dir);
> + location.offset = 0;
> + btrfs_set_key_type(&location, BTRFS_INODE_ITEM_KEY);
> +
> + ret = btrfs_lookup_inode(trans, root, path, &location, 0);
> if (ret < 0) {
> err = ret;
> goto out;
> @@ -2894,8 +2906,11 @@ static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
> }
> btrfs_release_path(path);
>
> - ret = btrfs_lookup_inode(trans, root, path,
> - &BTRFS_I(inode)->location, 0);
> + location.objectid = btrfs_ino(inode);
> + location.offset = 0;
> + btrfs_set_key_type(&location, BTRFS_INODE_ITEM_KEY);
> +
> + ret = btrfs_lookup_inode(trans, root, path, &location, 0);
> if (ret < 0) {
> err = ret;
> goto out;
> @@ -3097,7 +3112,7 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
>
> if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
> err = btrfs_unlink_subvol(trans, root, dir,
> - BTRFS_I(inode)->location.objectid,
> + BTRFS_I(inode)->inode_id,
> dentry->d_name.name,
> dentry->d_name.len);
> goto out;
> @@ -3331,7 +3346,7 @@ delete:
> if (path->slots[0] == 0 ||
> path->slots[0] != pending_del_slot) {
> if (root->ref_cows &&
> - BTRFS_I(inode)->location.objectid !=
> + BTRFS_I(inode)->inode_id !=
> BTRFS_FREE_INO_OBJECTID) {
> err = -EAGAIN;
> goto out;
> @@ -3965,7 +3980,7 @@ struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
>
> if (inode->i_state & I_NEW) {
> BTRFS_I(inode)->root = root;
> - memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
> + BTRFS_I(inode)->inode_id = location->objectid;
memcpy -> direct assignment
> btrfs_read_locked_inode(inode);
> inode_tree_add(inode);
> unlock_new_inode(inode);
> @@ -3986,7 +4001,7 @@ static struct inode *new_simple_dir(struct super_block *s,
> return ERR_PTR(-ENOMEM);
>
> BTRFS_I(inode)->root = root;
> - memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
> + BTRFS_I(inode)->inode_id = key->objectid;
memcpy -> direct assignment
> BTRFS_I(inode)->dummy_inode = 1;
>
> inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
> @@ -4417,7 +4432,6 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
> {
> struct inode *inode;
> struct btrfs_inode_item *inode_item;
> - struct btrfs_key *location;
> struct btrfs_path *path;
> struct btrfs_inode_ref *ref;
> struct btrfs_key key[2];
> @@ -4461,6 +4475,7 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
> BTRFS_I(inode)->generation = trans->transid;
> inode->i_generation = BTRFS_I(inode)->generation;
> btrfs_set_inode_space_info(root, inode);
> + BTRFS_I(inode)->inode_id = objectid;
>
> if (mode & S_IFDIR)
> owner = 0;
> @@ -4500,11 +4515,6 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
> btrfs_mark_buffer_dirty(path->nodes[0]);
> btrfs_free_path(path);
>
> - location = &BTRFS_I(inode)->location;
> - location->objectid = objectid;
> - location->offset = 0;
> - btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
> -
> btrfs_inherit_iflags(inode, dir);
>
> if ((mode & S_IFREG)) {
> @@ -7029,7 +7039,7 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
> new_inode->i_ctime = CURRENT_TIME;
> if (unlikely(btrfs_ino(new_inode) ==
> BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
> - root_objectid = BTRFS_I(new_inode)->location.objectid;
> + root_objectid = BTRFS_I(new_inode)->inode_id;
direct assignment, no btrfs_ino as in the first hunk
> ret = btrfs_unlink_subvol(trans, dest, new_dir,
> root_objectid,
> new_dentry->d_name.name,
> --
david
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