Linux 2.6.36 compat, fs_struct->lock type change

In the linux-2.6.36 kernel the fs_struct lock was changed from a
rwlock_t to a spinlock_t.  If the kernel would export the set_fs_pwd()
symbol by default this would not have caused us any issues, but they
don't.  So we're forced to add a new autoconf check which sets the
HAVE_FS_STRUCT_SPINLOCK define when a spinlock_t is used.  We can
then correctly use either spin_lock or write_lock in our custom
set_fs_pwd() implementation.
This commit is contained in:
Brian Behlendorf
2010-11-09 11:15:32 -08:00
parent a50cede388
commit 9b2048c26b
4 changed files with 176 additions and 8 deletions
Vendored
+134
View File
@@ -14903,6 +14903,73 @@ fi
{ $as_echo "$as_me:$LINENO: checking whether struct fs_struct uses spinlock_t" >&5
$as_echo_n "checking whether struct fs_struct uses spinlock_t... " >&6; }
cat confdefs.h - <<_ACEOF >conftest.c
/* confdefs.h. */
_ACEOF
cat confdefs.h >>conftest.$ac_ext
cat >>conftest.$ac_ext <<_ACEOF
/* end confdefs.h. */
#include <linux/sched.h>
#include <linux/fs_struct.h>
int
main (void)
{
struct fs_struct fs;
spin_lock_init(&fs.lock);
;
return 0;
}
_ACEOF
rm -Rf build && mkdir -p build
echo "obj-m := conftest.o" >build/Makefile
if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
{ (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
(eval $ac_try) 2>&5
ac_status=$?
$as_echo "$as_me:$LINENO: \$? = $ac_status" >&5
(exit $ac_status); }; } >/dev/null && { ac_try='test -s build/conftest.o'
{ (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
(eval $ac_try) 2>&5
ac_status=$?
$as_echo "$as_me:$LINENO: \$? = $ac_status" >&5
(exit $ac_status); }; }; then
{ $as_echo "$as_me:$LINENO: result: yes" >&5
$as_echo "yes" >&6; }
cat >>confdefs.h <<\_ACEOF
#define HAVE_FS_STRUCT_SPINLOCK 1
_ACEOF
else
$as_echo "$as_me: failed program was:" >&5
sed 's/^/| /' conftest.$ac_ext >&5
{ $as_echo "$as_me:$LINENO: result: no" >&5
$as_echo "no" >&6; }
fi
rm -Rf build
{ $as_echo "$as_me:$LINENO: checking whether struct cred exists" >&5
$as_echo_n "checking whether struct cred exists... " >&6; }
@@ -18525,6 +18592,73 @@ fi
{ $as_echo "$as_me:$LINENO: checking whether struct fs_struct uses spinlock_t" >&5
$as_echo_n "checking whether struct fs_struct uses spinlock_t... " >&6; }
cat confdefs.h - <<_ACEOF >conftest.c
/* confdefs.h. */
_ACEOF
cat confdefs.h >>conftest.$ac_ext
cat >>conftest.$ac_ext <<_ACEOF
/* end confdefs.h. */
#include <linux/sched.h>
#include <linux/fs_struct.h>
int
main (void)
{
struct fs_struct fs;
spin_lock_init(&fs.lock);
;
return 0;
}
_ACEOF
rm -Rf build && mkdir -p build
echo "obj-m := conftest.o" >build/Makefile
if { ac_try='cp conftest.c build && make modules -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build'
{ (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
(eval $ac_try) 2>&5
ac_status=$?
$as_echo "$as_me:$LINENO: \$? = $ac_status" >&5
(exit $ac_status); }; } >/dev/null && { ac_try='test -s build/conftest.o'
{ (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
(eval $ac_try) 2>&5
ac_status=$?
$as_echo "$as_me:$LINENO: \$? = $ac_status" >&5
(exit $ac_status); }; }; then
{ $as_echo "$as_me:$LINENO: result: yes" >&5
$as_echo "yes" >&6; }
cat >>confdefs.h <<\_ACEOF
#define HAVE_FS_STRUCT_SPINLOCK 1
_ACEOF
else
$as_echo "$as_me: failed program was:" >&5
sed 's/^/| /' conftest.$ac_ext >&5
{ $as_echo "$as_me:$LINENO: result: no" >&5
$as_echo "no" >&6; }
fi
rm -Rf build
{ $as_echo "$as_me:$LINENO: checking whether struct cred exists" >&5
$as_echo_n "checking whether struct cred exists... " >&6; }