Linux 3.1 compat, kern_path_parent()

Prior to Linux 3.1 the kern_path_parent symbol was exported for
use by kernel modules.  As of Linux 3.1 it is now longer easily
available.  To handle this case the spl will now dynamically
look up address of the missing symbol at module load time.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #52
This commit is contained in:
Brian Behlendorf 2011-11-09 12:29:51 -08:00
parent b8b6e4c453
commit 12ff95ff57
7 changed files with 152 additions and 19 deletions

View File

@ -80,7 +80,8 @@ AC_DEFUN([SPL_AC_CONFIG_KERNEL], [
SPL_AC_KERNEL_2ARGS_INVALIDATE_INODES
SPL_AC_SHRINK_DCACHE_MEMORY
SPL_AC_SHRINK_ICACHE_MEMORY
SPL_AC_KERN_PATH_PARENT
SPL_AC_KERN_PATH_PARENT_HEADER
SPL_AC_KERN_PATH_PARENT_SYMBOL
SPL_AC_2ARGS_ZLIB_DEFLATE_WORKSPACESIZE
SPL_AC_SHRINK_CONTROL_STRUCT
])
@ -587,6 +588,30 @@ AC_DEFUN([SPL_CHECK_SYMBOL_EXPORT],
fi
])
dnl #
dnl # SPL_CHECK_SYMBOL_HEADER
dnl # check if a symbol prototype is defined in listed headers.
dnl #
AC_DEFUN([SPL_CHECK_SYMBOL_HEADER], [
AC_MSG_CHECKING([whether symbol $1 exists in header])
header=0
for file in $3; do
grep -q "$2" "$LINUX/$file" 2>/dev/null
rc=$?
if test $rc -eq 0; then
header=1
break;
fi
done
if test $header -eq 0; then
AC_MSG_RESULT([no])
$5
else
AC_MSG_RESULT([yes])
$4
fi
])
dnl #
dnl # SPL_CHECK_HEADER
dnl # check whether header exists and define HAVE_$2_HEADER
@ -1809,11 +1834,27 @@ dnl # and the flags argument has been removed. The only behavior now
dnl # offered is that of LOOKUP_PARENT. The spl already always passed
dnl # this flag so dropping the flag does not impact us.
dnl #
AC_DEFUN([SPL_AC_KERN_PATH_PARENT], [
AC_DEFUN([SPL_AC_KERN_PATH_PARENT_HEADER], [
SPL_CHECK_SYMBOL_HEADER(
[kern_path_parent],
[int kern_path_parent(const char \*, struct nameidata \*)],
[include/linux/namei.h],
[AC_DEFINE(HAVE_KERN_PATH_PARENT_HEADER, 1,
[kern_path_parent() is available])],
[])
])
dnl #
dnl # 3.1 API compat,
dnl # The kern_path_parent() symbol is no longer exported by the kernel.
dnl # However, it remains the prefered interface and since we still have
dnl # access to the prototype we dynamically lookup the required address.
dnl #
AC_DEFUN([SPL_AC_KERN_PATH_PARENT_SYMBOL], [
SPL_CHECK_SYMBOL_EXPORT(
[kern_path_parent],
[fs/namei.c],
[AC_DEFINE(HAVE_KERN_PATH_PARENT, 1,
[AC_DEFINE(HAVE_KERN_PATH_PARENT_SYMBOL, 1,
[kern_path_parent() is available])],
[])
])

64
configure vendored
View File

@ -15684,6 +15684,34 @@ _ACEOF
{ $as_echo "$as_me:$LINENO: checking whether symbol kern_path_parent exists in header" >&5
$as_echo_n "checking whether symbol kern_path_parent exists in header... " >&6; }
header=0
for file in include/linux/namei.h; do
grep -q "int kern_path_parent(const char \*, struct nameidata \*)" "$LINUX/$file" 2>/dev/null
rc=$?
if test $rc -eq 0; then
header=1
break;
fi
done
if test $header -eq 0; then
{ $as_echo "$as_me:$LINENO: result: no" >&5
$as_echo "no" >&6; }
else
{ $as_echo "$as_me:$LINENO: result: yes" >&5
$as_echo "yes" >&6; }
cat >>confdefs.h <<\_ACEOF
#define HAVE_KERN_PATH_PARENT_HEADER 1
_ACEOF
fi
{ $as_echo "$as_me:$LINENO: checking whether symbol kern_path_parent is exported" >&5
$as_echo_n "checking whether symbol kern_path_parent is exported... " >&6; }
grep -q -E '[[:space:]]kern_path_parent[[:space:]]' \
@ -15709,7 +15737,7 @@ $as_echo "no" >&6; }
$as_echo "yes" >&6; }
cat >>confdefs.h <<\_ACEOF
#define HAVE_KERN_PATH_PARENT 1
#define HAVE_KERN_PATH_PARENT_SYMBOL 1
_ACEOF
fi
@ -15718,7 +15746,7 @@ _ACEOF
$as_echo "yes" >&6; }
cat >>confdefs.h <<\_ACEOF
#define HAVE_KERN_PATH_PARENT 1
#define HAVE_KERN_PATH_PARENT_SYMBOL 1
_ACEOF
fi
@ -19885,6 +19913,34 @@ _ACEOF
{ $as_echo "$as_me:$LINENO: checking whether symbol kern_path_parent exists in header" >&5
$as_echo_n "checking whether symbol kern_path_parent exists in header... " >&6; }
header=0
for file in include/linux/namei.h; do
grep -q "int kern_path_parent(const char \*, struct nameidata \*)" "$LINUX/$file" 2>/dev/null
rc=$?
if test $rc -eq 0; then
header=1
break;
fi
done
if test $header -eq 0; then
{ $as_echo "$as_me:$LINENO: result: no" >&5
$as_echo "no" >&6; }
else
{ $as_echo "$as_me:$LINENO: result: yes" >&5
$as_echo "yes" >&6; }
cat >>confdefs.h <<\_ACEOF
#define HAVE_KERN_PATH_PARENT_HEADER 1
_ACEOF
fi
{ $as_echo "$as_me:$LINENO: checking whether symbol kern_path_parent is exported" >&5
$as_echo_n "checking whether symbol kern_path_parent is exported... " >&6; }
grep -q -E '[[:space:]]kern_path_parent[[:space:]]' \
@ -19910,7 +19966,7 @@ $as_echo "no" >&6; }
$as_echo "yes" >&6; }
cat >>confdefs.h <<\_ACEOF
#define HAVE_KERN_PATH_PARENT 1
#define HAVE_KERN_PATH_PARENT_SYMBOL 1
_ACEOF
fi
@ -19919,7 +19975,7 @@ _ACEOF
$as_echo "yes" >&6; }
cat >>confdefs.h <<\_ACEOF
#define HAVE_KERN_PATH_PARENT 1
#define HAVE_KERN_PATH_PARENT_SYMBOL 1
_ACEOF
fi

View File

@ -67,11 +67,17 @@ spl_filp_open(const char *name, int flags, int mode, int *err)
#define spl_inode_unlock(ip) (up(&(ip)->i_sem))
#endif /* HAVE_INODE_I_MUTEX */
#ifdef HAVE_KERN_PATH_PARENT
#define spl_kern_path_parent(path, nd) kern_path_parent(path, nd)
#ifdef HAVE_KERN_PATH_PARENT_HEADER
# ifndef HAVE_KERN_PATH_PARENT_SYMBOL
typedef int (*kern_path_parent_t)(const char *, struct nameidata *);
extern kern_path_parent_t kern_path_parent_fn;
# define spl_kern_path_parent(path, nd) kern_path_parent_fn(path, nd)
# else
# define spl_kern_path_parent(path, nd) kern_path_parent(path, nd)
# endif /* HAVE_KERN_PATH_PARENT_SYMBOL */
#else
#define spl_kern_path_parent(path, nd) path_lookup(path, LOOKUP_PARENT, nd)
#endif /* HAVE_KERN_PATH_PARENT */
# define spl_kern_path_parent(path, nd) path_lookup(path, LOOKUP_PARENT, nd)
#endif /* HAVE_KERN_PATH_PARENT_HEADER */
#endif /* SPL_FILE_COMPAT_H */

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@ -189,8 +189,9 @@ extern file_t *vn_getf(int fd);
extern void vn_releasef(int fd);
extern int vn_set_pwd(const char *filename);
int vn_init(void);
void vn_fini(void);
int spl_vn_init_kallsyms_lookup(void);
int spl_vn_init(void);
void spl_vn_fini(void);
#define VOP_CLOSE vn_close
#define VOP_SEEK vn_seek

View File

@ -561,7 +561,7 @@ __init spl_init(void)
if ((rc = spl_taskq_init()))
SGOTO(out4, rc);
if ((rc = vn_init()))
if ((rc = spl_vn_init()))
SGOTO(out5, rc);
if ((rc = proc_init()))
@ -594,6 +594,9 @@ __init spl_init(void)
if ((rc = spl_kmem_init_kallsyms_lookup()))
SGOTO(out10, rc);
if ((rc = spl_vn_init_kallsyms_lookup()))
SGOTO(out10, rc);
printk(KERN_NOTICE "SPL: Loaded module v%s%s, using hostid 0x%08x\n",
SPL_META_VERSION, SPL_DEBUG_STR, (unsigned int) spl_hostid);
SRETURN(rc);
@ -606,7 +609,7 @@ __init spl_init(void)
out7:
proc_fini();
out6:
vn_fini();
spl_vn_fini();
out5:
spl_taskq_fini();
out4:
@ -634,7 +637,7 @@ spl_fini(void)
tsd_fini();
kstat_fini();
proc_fini();
vn_fini();
spl_vn_fini();
spl_taskq_fini();
spl_rw_fini();
spl_mutex_fini();

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@ -42,6 +42,13 @@ static spl_kmem_cache_t *vn_file_cache;
static DEFINE_SPINLOCK(vn_file_lock);
static LIST_HEAD(vn_file_list);
#ifdef HAVE_KERN_PATH_PARENT_HEADER
#ifndef HAVE_KERN_PATH_PARENT_SYMBOL
kern_path_parent_t kern_path_parent_fn = SYMBOL_POISON;
EXPORT_SYMBOL(kern_path_parent_fn);
#endif /* HAVE_KERN_PATH_PARENT_SYMBOL */
#endif /* HAVE_KERN_PATH_PARENT_HEADER */
vtype_t
vn_mode_to_vtype(mode_t mode)
{
@ -789,8 +796,24 @@ vn_file_cache_destructor(void *buf, void *cdrarg)
mutex_destroy(&fp->f_lock);
} /* vn_file_cache_destructor() */
int spl_vn_init_kallsyms_lookup(void)
{
#ifdef HAVE_KERN_PATH_PARENT_HEADER
#ifndef HAVE_KERN_PATH_PARENT_SYMBOL
kern_path_parent_fn = (kern_path_parent_t)
spl_kallsyms_lookup_name("kern_path_parent");
if (!kern_path_parent_fn) {
printk(KERN_ERR "Error: Unknown symbol kern_path_parent\n");
return -EFAULT;
}
#endif /* HAVE_KERN_PATH_PARENT_SYMBOL */
#endif /* HAVE_KERN_PATH_PARENT_HEADER */
return (0);
}
int
vn_init(void)
spl_vn_init(void)
{
SENTRY;
vn_cache = kmem_cache_create("spl_vn_cache",
@ -808,7 +831,7 @@ vn_init(void)
} /* vn_init() */
void
vn_fini(void)
spl_vn_fini(void)
{
file_t *fp, *next_fp;
int leaked = 0;

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@ -115,7 +115,10 @@
#undef HAVE_KALLSYMS_LOOKUP_NAME
/* kern_path_parent() is available */
#undef HAVE_KERN_PATH_PARENT
#undef HAVE_KERN_PATH_PARENT_HEADER
/* kern_path_parent() is available */
#undef HAVE_KERN_PATH_PARENT_SYMBOL
/* kmalloc_node() is available */
#undef HAVE_KMALLOC_NODE