Filipe David Borba Manana
2013-Sep-16 08:53 UTC
[PATCH] 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 <fdmanana@gmail.com> --- fs/btrfs/inode.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 85a4900..15e9d36 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -8334,7 +8334,7 @@ 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; @@ -8422,7 +8422,7 @@ 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; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html