[RFC] partitions: CONFIG_BLK_DEV_MD and modular RAID support

[RFC] partitions: CONFIG_BLK_DEV_MD and modular RAID support

[John Anthony Kazos Jr.]

(Linux v2.6.20.6.)

The function md_autodetect_dev is defined in drivers/md/md.c. Its 
declaration is on line 1443, outside of conditionals. However, both its 
use on line 1455 and its definition on line 5600 are inside "#ifndef 
MODULE" conditionals. So it seems obvious that the declaration should be 
inside conditionals as well.

However, this function is separately declared and used in 
fs/partitions/check.c but not inside the same conditional, which means if 
md.c is compiled as a module, check.c will be referencing an undefined 
symbol.

Should the conditionals around md_autodetect_dev be changed to make sure 
CONFIG_BLK_DEV_MD=y, or does the function need to be extracted from md.c 
so it can be used by check.c in any case?

Re: [RFC] partitions: CONFIG_BLK_DEV_MD and modular RAID support

[Randy Dunlap]

On Sat, 7 Apr 2007 18:47:20 -0400 (EDT) John Anthony Kazos Jr. wrote:

> (Linux v2.6.20.6.)
> 
> The function md_autodetect_dev is defined in drivers/md/md.c. Its 
> declaration is on line 1443, outside of conditionals. However, both its 
> use on line 1455 and its definition on line 5600 are inside "#ifndef 
> MODULE" conditionals. So it seems obvious that the declaration should be 
> inside conditionals as well.
> 
> However, this function is separately declared and used in 
> fs/partitions/check.c but not inside the same conditional, which means if 
> md.c is compiled as a module, check.c will be referencing an undefined 
> symbol.

I don't get a build error when BLK_DEV_MD=m.  Do you?

Do you want to determine why there is no build error?
Hint:  look at include/linux/autoconf.h.

> Should the conditionals around md_autodetect_dev be changed to make sure 
> CONFIG_BLK_DEV_MD=y, or does the function need to be extracted from md.c 
> so it can be used by check.c in any case?


---
~Randy
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