fs/crypto: make crypto.c explicitly non-modular
PATCH 1/1 fs/crypto: make crypto.c explicitly non-modular
As of commit 47134e6084f70fdf4381af75d4569cec6c7ebd50 ("fs crypto:
add Makefile and Kconfig") the compile of fs/crypto/crypto.c tripped my local audit for non-modules using modular infrastructure vs. their built in counterparts.
The Kconfig currently controlling compilation of this code is:
config FS_ENCRYPTION
bool "FS Encryption (Per-file encryption)"
combined with:
obj-$(CONFIG_FS_ENCRYPTION) += crypto.o policy.o keyinfo.o
...meaning that it currently is not being built as a module by anyone.
Lets remove the modular code that is essentially orphaned, so that when reading the driver there is no doubt it is builtin-only.
Since module_init translates to device_initcall in the non-modular case, the use of fs_initcall (which seems appropriate for fs code) means the init comes slightly earlier. However boot testing an x86-64 defconfig didn't show this to be causing any issues.
We replace module.h with moduleparam.h since the file does declare some module parameters, and leaving them as such is currently the easiest way to remain compatible with existing boot arg use cases.
--- fs/crypto/crypto.c | 22 ++++++---------------- 1 file changed, 6 insertions(+), 16 deletions(-)
fs/crypto/crypto.c +6 -16
@@ -23,7 +23,7 @@#include <linux/ecryptfs.h> #include <linux/pagemap.h> #include <linux/mempool.h> -#include <linux/module.h> +#include <linux/moduleparam.h> #include <linux/scatterlist.h> #include <linux/ratelimit.h> #include <linux/bio.h>
@@ -33,6 +33,10 @@static unsigned int num_prealloc_crypto_pages =32 ;static unsigned int num_prealloc_crypto_ctxs =128 ; +/* +* Not really modular but using module_param is the easiest way to +* remain consistent with existing use cases for now. +*/ module_param (num_prealloc_crypto_pages, uint,0444 );MODULE_PARM_DESC (num_prealloc_crypto_pages,"Number of crypto pages to preallocate" );
@@ -537,18 +541,4 @@ fail_free_queue: fail:return -ENOMEM ; } -module_init (fscrypt_init) - -/** -* fscrypt_exit() - Shutdown the fs encryption system -*/ -void __exit fscrypt_exit(void) -{ -fscrypt_destroy (); - -if (fscrypt_read_workqueue) -destroy_workqueue (fscrypt_read_workqueue); -kmem_cache_destroy (fscrypt_ctx_cachep); -kmem_cache_destroy (fscrypt_info_cachep); -} -module_exit (fscrypt_exit); +fs_initcall (fscrypt_init)
Signature · 1 line
2.6.1
Quoted 19 lines · On Saturday 27 February 2016 15:20:49 Paul Gortmaker wrote:
As of commit
47134e6084f70fdf4381af75d4569cec6c7ebd50("fs crypto:
addMakefileandKconfig") the compile offs/crypto/crypto.ctripped my local audit for non-modules using modular infrastructure vs. their built in counterparts.The
Kconfigcurrently controlling compilation of this code is:config
FS_ENCRYPTION
bool "FS Encryption (Per-file encryption)"combined with:
obj-$(CONFIG_FS_ENCRYPTION) += crypto.o policy.o keyinfo.o
...meaning that it currently is not being built as a module by anyone.
Lets remove the modular code that is essentially orphaned, so that when reading the driver there is no doubt it is builtin-only.
Quoted 9 lines
Since
module_inittranslates todevice_initcallin the non-modular case, the use offs_initcall(which seems appropriate for fs code) means the init comes slightly earlier. However boot testing an x86-64 defconfig didn't show this to be causing any issues.We replace
module.hwithmoduleparam.hsince the file does declare some module parameters, and leaving them as such is currently the easiest way to remain compatible with existing boot arg use cases.
So why not make the option a 'tristate' instead? It looks like that was intended here, and we should always try to make all code loadable as modules if possible.
Arnd
Quoted 25 lines · [Re: [PATCH] fs/crypto: make crypto.c explicitly non-modular] On 29/02/2016…
Quoted 24 lines · On Saturday 27 February 2016 15:20:49 Paul Gortmaker wrote:
As of commit
47134e6084f70fdf4381af75d4569cec6c7ebd50("fs crypto:
addMakefileandKconfig") the compile offs/crypto/crypto.ctripped my local audit for non-modules using modular infrastructure vs. their built in counterparts.The
Kconfigcurrently controlling compilation of this code is:config
FS_ENCRYPTION
bool "FS Encryption (Per-file encryption)"combined with:
obj-$(CONFIG_FS_ENCRYPTION) += crypto.o policy.o keyinfo.o
...meaning that it currently is not being built as a module by anyone.
Lets remove the modular code that is essentially orphaned, so that when reading the driver there is no doubt it is builtin-only.
Since
module_inittranslates todevice_initcallin the non-modular case, the use offs_initcall(which seems appropriate for fs code) means the init comes slightly earlier. However boot testing an x86-64 defconfig didn't show this to be causing any issues.
Quoted 8 lines
Quoted 4 lines
We replace
module.hwithmoduleparam.hsince the file does declare some module parameters, and leaving them as such is currently the easiest way to remain compatible with existing boot arg use cases.So why not make the option a 'tristate' instead? It looks like that was intended here, and we should always try to make all code loadable as modules if possible.
It wasn't that obvious to me, and at the risk of repeating myself, I'll always default to making the code consistent with existing functionality vs. making assumptions about what was intended and implicitly adding new functionality that may be invalid for reasons I'd never spot.
Of course authors, and maintainers are welcome to chime in and steer it one way or another as per the PCI patches.
Paul.
--
Quoted 2 lines
Arnd
Jaegeuk Kim
maintainerHi Paul,
Quoted 36 lines · Paul Gortmaker
Quoted 25 lines · [Re: [PATCH] fs/crypto: make crypto.c explicitly non-modular] On 29/02/2016…
Quoted 24 lines · On Saturday 27 February 2016 15:20:49 Paul Gortmaker wrote:
As of commit
47134e6084f70fdf4381af75d4569cec6c7ebd50("fs crypto:
addMakefileandKconfig") the compile offs/crypto/crypto.ctripped my local audit for non-modules using modular infrastructure vs. their built in counterparts.The
Kconfigcurrently controlling compilation of this code is:config
FS_ENCRYPTION
bool "FS Encryption (Per-file encryption)"combined with:
obj-$(CONFIG_FS_ENCRYPTION) += crypto.o policy.o keyinfo.o
...meaning that it currently is not being built as a module by anyone.
Lets remove the modular code that is essentially orphaned, so that when reading the driver there is no doubt it is builtin-only.
Since
module_inittranslates todevice_initcallin the non-modular case, the use offs_initcall(which seems appropriate for fs code) means the init comes slightly earlier. However boot testing an x86-64 defconfig didn't show this to be causing any issues.Quoted 8 lines
Quoted 4 lines
We replace
module.hwithmoduleparam.hsince the file does declare some module parameters, and leaving them as such is currently the easiest way to remain compatible with existing boot arg use cases.So why not make the option a 'tristate' instead? It looks like that was intended here, and we should always try to make all code loadable as modules if possible.
Quoted 7 lines
It wasn't that obvious to me, and at the risk of repeating myself, I'll always default to making the code consistent with existing functionality vs. making assumptions about what was intended and implicitly adding new functionality that may be invalid for reasons I'd never spot.
Of course authors, and maintainers are welcome to chime in and steer it one way or another as per the PCI patches.
Meanwhile, I've modified and tested fscrypt as a module, as Arnd commented. I'll submit v3 to resolve this inconsistency.
Thank you for the point that I missed.
Quoted 6 lines
Paul.
--Quoted 2 lines
Arnd