Linux 4.0 compat: bdi_setup_and_register()

The 'capabilities' argument which was passed to bdi_setup_and_register()
has been removed.  File systems should no longer pass BDI_CAP_MAP_COPY.
For our purposes this means there are now three different interfaces
which must be handled.  A zpl_bdi_setup_and_register() wrapper function
has been introduced to provide a single interface to the ZPL code.

* 2.6.32 - 2.6.33, bdi_setup_and_register() is not exported.
* 2.6.34 - 3.19, bdi_setup_and_register() takes 3 arguments.
* 4.0 - x.y, bdi_setup_and_register() takes 2 arguments.

I've also taken this opportunity to remove HAVE_BDI because kernels
older then 2.6.32 are no longer supported.  All kernels newer than
this will have one of the above interfaces.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Closes #3128
This commit is contained in:
Brian Behlendorf 2015-02-27 16:09:52 -08:00
parent 4ec15b8dcf
commit 8c45def24a
5 changed files with 49 additions and 60 deletions

View File

@ -1,22 +1,36 @@
dnl #
dnl # 2.6.34 API change
dnl # The bdi_setup_and_register() helper function is avaliable and
dnl # exported by the kernel. This is a trivial helper function but
dnl # using it significantly simplifies the code surrounding setting
dnl # up and tearing down the bdi structure.
dnl # 2.6.32 - 2.6.33, bdi_setup_and_register() is not exported.
dnl # 2.6.34 - 3.19, bdi_setup_and_register() takes 3 arguments.
dnl # 4.0 - x.y, bdi_setup_and_register() takes 2 arguments.
dnl #
AC_DEFUN([ZFS_AC_KERNEL_BDI_SETUP_AND_REGISTER],
[AC_MSG_CHECKING([whether bdi_setup_and_register() is available])
AC_DEFUN([ZFS_AC_KERNEL_BDI_SETUP_AND_REGISTER], [
AC_MSG_CHECKING([whether bdi_setup_and_register() wants 2 args])
ZFS_LINUX_TRY_COMPILE_SYMBOL([
#include <linux/backing-dev.h>
], [
int r = bdi_setup_and_register(NULL, NULL, 0);
r = *(&r);
struct backing_dev_info bdi;
char *name = "bdi";
(void) bdi_setup_and_register(&bdi, name);
], [bdi_setup_and_register], [mm/backing-dev.c], [
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_BDI_SETUP_AND_REGISTER, 1,
[bdi_setup_and_register() is available])
AC_DEFINE(HAVE_2ARGS_BDI_SETUP_AND_REGISTER, 1,
[bdi_setup_and_register() wants 2 args])
], [
AC_MSG_RESULT(no)
AC_MSG_CHECKING([whether bdi_setup_and_register() wants 3 args])
ZFS_LINUX_TRY_COMPILE_SYMBOL([
#include <linux/backing-dev.h>
], [
struct backing_dev_info bdi;
char *name = "bdi";
unsigned int cap = BDI_CAP_MAP_COPY;
(void) bdi_setup_and_register(&bdi, name, cap);
], [bdi_setup_and_register], [mm/backing-dev.c], [
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_3ARGS_BDI_SETUP_AND_REGISTER, 1,
[bdi_setup_and_register() wants 3 args])
], [
AC_MSG_RESULT(no)
])
])
])

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@ -1,21 +0,0 @@
dnl #
dnl # 2.6.32 API change
dnl # Private backing_device_info interfaces available
dnl #
AC_DEFUN([ZFS_AC_KERNEL_BDI], [
AC_MSG_CHECKING([whether super_block has s_bdi])
ZFS_LINUX_TRY_COMPILE([
#include <linux/fs.h>
static const struct super_block
sb __attribute__ ((unused)) = {
.s_bdi = NULL,
};
],[
],[
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_BDI, 1, [struct super_block has s_bdi])
],[
AC_MSG_RESULT(no)
])
])

View File

@ -90,7 +90,6 @@ AC_DEFUN([ZFS_AC_CONFIG_KERNEL], [
ZFS_AC_KERNEL_SHRINK
ZFS_AC_KERNEL_S_INSTANCES_LIST_HEAD
ZFS_AC_KERNEL_S_D_OP
ZFS_AC_KERNEL_BDI
ZFS_AC_KERNEL_BDI_SETUP_AND_REGISTER
ZFS_AC_KERNEL_SET_NLINK
ZFS_AC_KERNEL_ELEVATOR_CHANGE

View File

@ -65,25 +65,35 @@ truncate_setsize(struct inode *ip, loff_t new)
}
#endif /* HAVE_TRUNCATE_SETSIZE */
#if defined(HAVE_BDI) && !defined(HAVE_BDI_SETUP_AND_REGISTER)
/*
* 2.6.34 API change,
* Add bdi_setup_and_register() function if not yet provided by kernel.
* It is used to quickly initialize and register a BDI for the filesystem.
* 2.6.32 - 2.6.33, bdi_setup_and_register() is not available.
* 2.6.34 - 3.19, bdi_setup_and_register() takes 3 arguments.
* 4.0 - x.y, bdi_setup_and_register() takes 2 arguments.
*/
#if defined(HAVE_2ARGS_BDI_SETUP_AND_REGISTER)
static inline int
zpl_bdi_setup_and_register(struct backing_dev_info *bdi, char *name)
{
return (bdi_setup_and_register(bdi, name));
}
#elif defined(HAVE_3ARGS_BDI_SETUP_AND_REGISTER)
static inline int
zpl_bdi_setup_and_register(struct backing_dev_info *bdi, char *name)
{
return (bdi_setup_and_register(bdi, name, BDI_CAP_MAP_COPY));
}
#else
extern atomic_long_t zfs_bdi_seq;
static inline int
bdi_setup_and_register(
struct backing_dev_info *bdi,
char *name,
unsigned int cap)
zpl_bdi_setup_and_register(struct backing_dev_info *bdi, char *name)
{
char tmp[32];
int error;
bdi->name = name;
bdi->capabilities = cap;
bdi->capabilities = BDI_CAP_MAP_COPY;
error = bdi_init(bdi);
if (error)
return (error);
@ -98,7 +108,7 @@ bdi_setup_and_register(
return (error);
}
#endif /* HAVE_BDI && !HAVE_BDI_SETUP_AND_REGISTER */
#endif
/*
* 2.6.38 API change,

View File

@ -1198,9 +1198,10 @@ zfs_sb_teardown(zfs_sb_t *zsb, boolean_t unmounting)
}
EXPORT_SYMBOL(zfs_sb_teardown);
#if defined(HAVE_BDI) && !defined(HAVE_BDI_SETUP_AND_REGISTER)
#if !defined(HAVE_2ARGS_BDI_SETUP_AND_REGISTER) && \
!defined(HAVE_3ARGS_BDI_SETUP_AND_REGISTER)
atomic_long_t zfs_bdi_seq = ATOMIC_LONG_INIT(0);
#endif /* HAVE_BDI && !HAVE_BDI_SETUP_AND_REGISTER */
#endif
int
zfs_domount(struct super_block *sb, void *data, int silent)
@ -1227,23 +1228,12 @@ zfs_domount(struct super_block *sb, void *data, int silent)
sb->s_time_gran = 1;
sb->s_blocksize = recordsize;
sb->s_blocksize_bits = ilog2(recordsize);
#ifdef HAVE_BDI
/*
* 2.6.32 API change,
* Added backing_device_info (BDI) per super block interfaces. A BDI
* must be configured when using a non-device backed filesystem for
* proper writeback. This is not required for older pdflush kernels.
*
* NOTE: Linux read-ahead is disabled in favor of zfs read-ahead.
*/
zsb->z_bdi.ra_pages = 0;
sb->s_bdi = &zsb->z_bdi;
error = -bdi_setup_and_register(&zsb->z_bdi, "zfs", BDI_CAP_MAP_COPY);
error = -zpl_bdi_setup_and_register(&zsb->z_bdi, "zfs");
if (error)
goto out;
#endif /* HAVE_BDI */
/* Set callback operations for the file system. */
sb->s_op = &zpl_super_operations;
@ -1336,10 +1326,7 @@ zfs_umount(struct super_block *sb)
VERIFY(zfs_sb_teardown(zsb, B_TRUE) == 0);
os = zsb->z_os;
#ifdef HAVE_BDI
bdi_destroy(sb->s_bdi);
#endif /* HAVE_BDI */
/*
* z_os will be NULL if there was an error in