From: Filipe David Borba Manana Date: Mon, 16 Sep 2013 08:53:28 +0000 (+0100) Subject: Btrfs: don't store NULL byte in symlink extents X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=f06becc4119856c984e3beef54aa75538e656c6d;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git Btrfs: don't store NULL byte in symlink extents It is not necessary to store the NULL byte in a symlink inline file extent. There's currently no code that requires the NULL byte to be present in the extent. This change also doesn't break file format compatibility nor the send/receive feature. The VFS also doesn't need the NULL byte to be present in the extent, as it reads up to inode->i_size bytes (which already excluded the NULL byte) and sets the NULL byte for us (in fs/namei.c:page_getlink()). So with this change we save 1 byte per symlink file extent (which is always inlined in the btree leaf) without losing backward and forward compatibility. Signed-off-by: Filipe David Borba Manana Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index dfc60aa40332..59b4e2e495ac 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -8339,7 +8339,7 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry, struct btrfs_file_extent_item *ei; struct extent_buffer *leaf; - name_len = strlen(symname) + 1; + name_len = strlen(symname); if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root)) return -ENAMETOOLONG; @@ -8427,7 +8427,7 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry, inode->i_mapping->a_ops = &btrfs_symlink_aops; inode->i_mapping->backing_dev_info = &root->fs_info->bdi; inode_set_bytes(inode, name_len); - btrfs_i_size_write(inode, name_len - 1); + btrfs_i_size_write(inode, name_len); err = btrfs_update_inode(trans, root, inode); if (err) drop_inode = 1;