Check whether the kernel supports i_uid/gid_read/write helpers

Since the concept of a kuid and the need to translate from it to
ordinary integer type was added in kernel version 3.5 implement necessary
plumbing to be able to detect this condition during compile time. If
the kernel doesn't support the kuid then just fall back to directly
accessing the respective struct inode's members

Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #4685
Issue #227
This commit is contained in:
Nikolay Borisov 2016-05-30 20:37:36 +03:00 committed by Brian Behlendorf
parent 77943bc1dc
commit 82a1b2d628
3 changed files with 76 additions and 0 deletions

View File

@ -0,0 +1,22 @@
dnl #
dnl # 3.5 API change,
dnl # Since usernamespaces were introduced in kernel version 3.5, it
dnl # became necessary to go through one more level of indirection
dnl # when dealing with uid/gid - namely the kuid type.
dnl #
dnl #
AC_DEFUN([ZFS_AC_KERNEL_KUID_HELPERS], [
AC_MSG_CHECKING([whether i_(uid|gid)_(read|write) exist])
ZFS_LINUX_TRY_COMPILE([
#include <linux/fs.h>
],[
struct inode *ip = NULL;
(void) i_uid_read(ip);
],[
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_KUID_HELPERS, 1,
[i_(uid|gid)_(read|write) exist])
],[
AC_MSG_RESULT(no)
])
])

View File

@ -92,6 +92,7 @@ AC_DEFUN([ZFS_AC_CONFIG_KERNEL], [
ZFS_AC_KERNEL_MAKE_REQUEST_FN
ZFS_AC_KERNEL_GENERIC_IO_ACCT
ZFS_AC_KERNEL_FPU
ZFS_AC_KERNEL_KUID_HELPERS
AS_IF([test "$LINUX_OBJ" != "$LINUX"], [
KERNELMAKE_PARAMS="$KERNELMAKE_PARAMS O=$LINUX_OBJ"

View File

@ -28,6 +28,7 @@
#define _ZFS_VFS_H
#include <sys/taskq.h>
#include <sys/cred.h>
#include <linux/backing-dev.h>
/*
@ -352,6 +353,58 @@ static inline struct inode *file_inode(const struct file *f)
}
#endif /* HAVE_FILE_INODE */
#ifdef HAVE_KUID_HELPERS
static inline uid_t zfs_uid_read_impl(struct inode *ip)
{
return (from_kuid(kcred->user_ns, ip->i_uid));
}
static inline uid_t zfs_uid_read(struct inode *ip)
{
return (zfs_uid_read_impl(ip));
}
static inline gid_t zfs_gid_read_impl(struct inode *ip)
{
return (from_kgid(kcred->user_ns, ip->i_gid));
}
static inline gid_t zfs_gid_read(struct inode *ip)
{
return (zfs_gid_read_impl(ip));
}
static inline void zfs_uid_write(struct inode *ip, uid_t uid)
{
ip->i_uid = make_kuid(kcred->user_ns, uid);
}
static inline void zfs_gid_write(struct inode *ip, gid_t gid)
{
ip->i_gid = make_kgid(kcred->user_ns, gid);
}
#else
static inline uid_t zfs_uid_read(struct inode *ip)
{
return (ip->i_uid);
}
static inline gid_t zfs_gid_read(struct inode *ip)
{
return (ip->i_gid);
}
static inline void zfs_uid_write(struct inode *ip, uid_t uid)
{
ip->i_uid = uid;
}
static inline void zfs_gid_write(struct inode *ip, gid_t gid)
{
ip->i_gid = gid;
}
#endif
/*
* 2.6.38 API change
*/