diff mbox series

[02/17] fs: remove the special !CONFIG_BLOCK def_blk_fops

Message ID 20230424054926.26927-3-hch@lst.de (mailing list archive)
State New, archived
Headers show
Series [01/17] fs: unexport buffer_check_dirty_writeback | expand

Commit Message

Christoph Hellwig April 24, 2023, 5:49 a.m. UTC 
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 <hch@lst.de>
---
 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

Comments

Randy Dunlap April 24, 2023, 7:22 p.m. UTC | #1 
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 <hch@lst.de>
> ---
>  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 (dhowells@redhat.com)
> - */
> -
> -#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,
> -};
Keith Busch April 24, 2023, 7:37 p.m. UTC | #2 
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.
diff mbox series

Patch

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;
 		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 (dhowells@redhat.com)
- */
-
-#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,
-};