| Message ID | 20180706132407.4069001-1-arnd@arndb.de |
|---|---|
| State | New |
| Headers | show |
| Series | sbitmap, scsi/target: add seq_file forward declaration | expand |
On Fri, 2018-07-06 at 15:23 +0200, Arnd Bergmann wrote: > The target core runs into a warning in the linux/sbitmap.h > file in some configurations: > > In file included from include/target/target_core_base.h:7, > from drivers/target/target_core_fabric_lib.c:41: > include/linux/sbitmap.h:331:46: error: 'struct seq_file' declared inside parameter list will not be visible outside of this definition or declaration [-Werror] > void sbitmap_show(struct sbitmap *sb, struct seq_file *m); > ^~~~~~~~ > > In general, headers should not depend on others being included first, > so this fixes it with a forward declaration for that struct name, but > we probably want to merge the patch through the scsi tree to help > bisection. > > Fixes: 10e9cbb6b531 ("scsi: target: Convert target drivers to use sbitmap") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > include/linux/sbitmap.h | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/include/linux/sbitmap.h b/include/linux/sbitmap.h > index e6539536dea9..cc54b9f7ff8b 100644 > --- a/include/linux/sbitmap.h > +++ b/include/linux/sbitmap.h > @@ -321,6 +321,8 @@ static inline int sbitmap_test_bit(struct sbitmap *sb, unsigned int bitnr) > > unsigned int sbitmap_weight(const struct sbitmap *sb); > > +struct seq_file; > + > /** > * sbitmap_show() - Dump &struct sbitmap information to a &struct seq_file. > * @sb: Bitmap to show. In many Linux kernel header files all forward declarations are grouped near the start of the header file (after #includes and #defines and before structure definitions). Should we follow that pattern in <linux/sbitmap.h>? Thanks, Bart.
On Fri, Jul 6, 2018 at 7:07 PM, Bart Van Assche <Bart.VanAssche@wdc.com> wrote: > On Fri, 2018-07-06 at 15:23 +0200, Arnd Bergmann wrote: >> The target core runs into a warning in the linux/sbitmap.h >> file in some configurations: >> >> In file included from include/target/target_core_base.h:7, >> from drivers/target/target_core_fabric_lib.c:41: >> include/linux/sbitmap.h:331:46: error: 'struct seq_file' declared inside parameter list will not be visible outside of this definition or declaration [-Werror] >> void sbitmap_show(struct sbitmap *sb, struct seq_file *m); >> ^~~~~~~~ >> >> In general, headers should not depend on others being included first, >> so this fixes it with a forward declaration for that struct name, but >> we probably want to merge the patch through the scsi tree to help >> bisection. >> >> Fixes: 10e9cbb6b531 ("scsi: target: Convert target drivers to use sbitmap") >> Signed-off-by: Arnd Bergmann <arnd@arndb.de> >> --- >> include/linux/sbitmap.h | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/include/linux/sbitmap.h b/include/linux/sbitmap.h >> index e6539536dea9..cc54b9f7ff8b 100644 >> --- a/include/linux/sbitmap.h >> +++ b/include/linux/sbitmap.h >> @@ -321,6 +321,8 @@ static inline int sbitmap_test_bit(struct sbitmap *sb, unsigned int bitnr) >> >> unsigned int sbitmap_weight(const struct sbitmap *sb); >> >> +struct seq_file; >> + >> /** >> * sbitmap_show() - Dump &struct sbitmap information to a &struct seq_file. >> * @sb: Bitmap to show. > > In many Linux kernel header files all forward declarations are grouped near > the start of the header file (after #includes and #defines and before structure > definitions). Should we follow that pattern in <linux/sbitmap.h>? I couldn't find any other such declaration in this header, so I just put it close to where it's first used, which is the other common way to do it. I checked all of include/linux and found that you are right, a clear majority of the headers just pull all struct declarations in the front. Arnd
diff --git a/include/linux/sbitmap.h b/include/linux/sbitmap.h index e6539536dea9..cc54b9f7ff8b 100644 --- a/include/linux/sbitmap.h +++ b/include/linux/sbitmap.h @@ -321,6 +321,8 @@ static inline int sbitmap_test_bit(struct sbitmap *sb, unsigned int bitnr) unsigned int sbitmap_weight(const struct sbitmap *sb); +struct seq_file; + /** * sbitmap_show() - Dump &struct sbitmap information to a &struct seq_file. * @sb: Bitmap to show.
The target core runs into a warning in the linux/sbitmap.h file in some configurations: In file included from include/target/target_core_base.h:7, from drivers/target/target_core_fabric_lib.c:41: include/linux/sbitmap.h:331:46: error: 'struct seq_file' declared inside parameter list will not be visible outside of this definition or declaration [-Werror] void sbitmap_show(struct sbitmap *sb, struct seq_file *m); ^~~~~~~~ In general, headers should not depend on others being included first, so this fixes it with a forward declaration for that struct name, but we probably want to merge the patch through the scsi tree to help bisection. Fixes: 10e9cbb6b531 ("scsi: target: Convert target drivers to use sbitmap") Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- include/linux/sbitmap.h | 2 ++ 1 file changed, 2 insertions(+) -- 2.9.0