Hi,
On 4/23/23 22:49, Christoph Hellwig wrote:
> def_blk_fops always returns -ENODEV, which dosn't match the return value
> of a non-existing block device with CONFIG_BLOCK, which is -ENXIO.
> Just remove the extra implementation and fall back to the default
> no_open_fops that always returns -ENXIO.
>
> Signed-off-by: Christoph Hellwig <[email protected]>
> ---
> fs/Makefile | 10 ++--------
> fs/inode.c | 3 ++-
> fs/no-block.c | 19 -------------------
> 3 files changed, 4 insertions(+), 28 deletions(-)
> delete mode 100644 fs/no-block.c
>
> diff --git a/fs/Makefile b/fs/Makefile
> index 05f89b5c962f88..da21e7d0a1cf37 100644
> --- a/fs/Makefile
> +++ b/fs/Makefile
> @@ -18,14 +18,8 @@ obj-y := open.o read_write.o file_table.o super.o \
> fs_types.o fs_context.o fs_parser.o fsopen.o init.o \
> kernel_read_file.o mnt_idmapping.o remap_range.o
>
> -ifeq ($(CONFIG_BLOCK),y)
> -obj-y += buffer.o mpage.o
> -else
> -obj-y += no-block.o
> -endif
> -
> -obj-$(CONFIG_PROC_FS) += proc_namespace.o
> -
> +obj-$(CONFIG_BLOCK) += buffer.o mpage.o
> +obj-$(CONFIG_PROC_FS) += proc_namespace.o
> obj-$(CONFIG_LEGACY_DIRECT_IO) += direct-io.o
> obj-y += notify/
> obj-$(CONFIG_EPOLL) += eventpoll.o
> diff --git a/fs/inode.c b/fs/inode.c
> index 4558dc2f135573..d43f07f146eb73 100644
> --- a/fs/inode.c
> +++ b/fs/inode.c
> @@ -2265,7 +2265,8 @@ void init_special_inode(struct inode *inode, umode_t mode, dev_t rdev)
> inode->i_fop = &def_chr_fops;
> inode->i_rdev = rdev;
> } else if (S_ISBLK(mode)) {
> - inode->i_fop = &def_blk_fops;
> + if (IS_ENABLED(CONFIG_BLOCK))
> + inode->i_fop = &def_blk_fops;
It looks like def_blk_fops is being removed (commit message and patch
fragment below), but here (above line) it is being used.
Am I just confused?
> inode->i_rdev = rdev;
> } else if (S_ISFIFO(mode))
> inode->i_fop = &pipefifo_fops;
> diff --git a/fs/no-block.c b/fs/no-block.c
> deleted file mode 100644
> index 481c0f0ab4bd2c..00000000000000
> --- a/fs/no-block.c
> +++ /dev/null
> @@ -1,19 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0-or-later
> -/* no-block.c: implementation of routines required for non-BLOCK configuration
> - *
> - * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
> - * Written by David Howells ([email protected])
> - */
> -
> -#include <linux/kernel.h>
> -#include <linux/fs.h>
> -
> -static int no_blkdev_open(struct inode * inode, struct file * filp)
> -{
> - return -ENODEV;
> -}
> -
> -const struct file_operations def_blk_fops = {
> - .open = no_blkdev_open,
> - .llseek = noop_llseek,
> -};
--
~Randy
On Mon, Apr 24, 2023 at 12:22:30PM -0700, Randy Dunlap wrote:
> On 4/23/23 22:49, Christoph Hellwig wrote:
> > + if (IS_ENABLED(CONFIG_BLOCK))
> > + inode->i_fop = &def_blk_fops;
>
> It looks like def_blk_fops is being removed (commit message and patch
> fragment below), but here (above line) it is being used.
>
> Am I just confused?
The def_blk_fops is removed only for the !CONFIG_BLOCK case. Its usage is under
a branch known at compile time, so it's optimized out for that case before
trying to resolve the symbol.