Linux 4.9 compat: group_info changes

In Linux 4.9, torvalds/linux@81243ea, group_info changed from 2d array via
->blocks to 1d array via ->gid. We change the spl cred functions accordingly.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes #581

diff --git a/config/spl-build.m4 b/config/spl-build.m4
index 94e692a8bfedf4c32fa868f215277e3d0e67318d..7e2e7a0a92d9421356b972b6b19577ce240abee0 100644 (file)
--- a/config/spl-build.m4
+++ b/config/spl-build.m4
@@ -49,6 +49,7 @@ AC_DEFUN([SPL_AC_CONFIG_KERNEL], [
        SPL_AC_WAIT_ON_BIT
        SPL_AC_MUTEX_OWNER
        SPL_AC_INODE_LOCK
+       SPL_AC_GROUP_INFO_GID
 ])
 
 AC_DEFUN([SPL_AC_MODULE_SYMVERS], [
@@ -1574,3 +1575,25 @@ AC_DEFUN([SPL_AC_INODE_LOCK], [
        ])
        EXTRA_KCFLAGS="$tmp_flags"
 ])
+
+dnl #
+dnl # 4.9 API change
+dnl # group_info changed from 2d array via >blocks to 1d array via ->gid
+dnl #
+AC_DEFUN([SPL_AC_GROUP_INFO_GID], [
+       AC_MSG_CHECKING([whether group_info->gid exists])
+       tmp_flags="$EXTRA_KCFLAGS"
+       EXTRA_KCFLAGS="-Werror"
+       SPL_LINUX_TRY_COMPILE([
+               #include <linux/cred.h>
+       ],[
+               struct group_info *gi = groups_alloc(1);
+               gi->gid[0] = KGIDT_INIT(0);
+       ],[
+               AC_MSG_RESULT(yes)
+               AC_DEFINE(HAVE_GROUP_INFO_GID, 1, [group_info->gid exists])
+       ],[
+               AC_MSG_RESULT(no)
+       ])
+       EXTRA_KCFLAGS="$tmp_flags"
+])

diff --git a/include/sys/cred.h b/include/sys/cred.h
index 58f7aafdaf4d31c7a29b48e803f0f52657d3de6e..2ad7115e0a3b22c7d287686aee4c7e5696d98065 100644 (file)
--- a/include/sys/cred.h
+++ b/include/sys/cred.h
@@ -34,6 +34,11 @@ typedef struct cred cred_t;
 #define        kcred           ((cred_t *)(init_task.cred))
 #define        CRED()          ((cred_t *)current_cred())
 
+/* Linux 4.9 API change, GROUP_AT was removed */
+#ifndef GROUP_AT
+#define        GROUP_AT(gi, i) ((gi)->gid[i])
+#endif
+
 #ifdef HAVE_KUIDGID_T
 
 #define        KUID_TO_SUID(x)         (__kuid_val(x))

diff --git a/module/spl/spl-cred.c b/module/spl/spl-cred.c
index d046f95132533ee375feedca8eb34dcde95998c4..1d486c1f0b1b62ceec02632abeba095d32b6cd55 100644 (file)
--- a/module/spl/spl-cred.c
+++ b/module/spl/spl-cred.c
@@ -85,7 +85,9 @@ crgetngroups(const cred_t *cr)
 
        gi = cr->group_info;
        rc = gi->ngroups;
+#ifndef HAVE_GROUP_INFO_GID
        /*
+        * For Linux <= 4.8,
         * crgetgroups will only returns gi->blocks[0], which contains only
         * the first NGROUPS_PER_BLOCK groups.
         */
@@ -93,12 +95,16 @@ crgetngroups(const cred_t *cr)
                WARN_ON_ONCE(1);
                rc = NGROUPS_PER_BLOCK;
        }
+#endif
        return rc;
 }
 
 /*
  * Return an array of supplemental gids.  The returned address is safe
  * to use as long as the caller has taken a reference with crhold().
+ *
+ * Linux 4.9 API change, group_info changed from 2d array via ->blocks to 1d
+ * array via ->gid.
  */
 gid_t *
 crgetgroups(const cred_t *cr)
@@ -107,8 +113,12 @@ crgetgroups(const cred_t *cr)
        gid_t *gids = NULL;
 
        gi = cr->group_info;
+#ifdef HAVE_GROUP_INFO_GID
+       gids = KGIDP_TO_SGIDP(gi->gid);
+#else
        if (gi->nblocks > 0)
                gids = KGIDP_TO_SGIDP(gi->blocks[0]);
+#endif
        return gids;
 }
 

diff --git a/module/splat/splat-cred.c b/module/splat/splat-cred.c
index e3d1c4eee061406aa4d587cefad8ff219e82d965..f6b70ce34ebe754eed3a57e14c4159d004f4f07b 100644 (file)
--- a/module/splat/splat-cred.c
+++ b/module/splat/splat-cred.c
@@ -166,6 +166,7 @@ splat_cred_test2(struct file *file, void *arg)
         return 0;
 } /* splat_cred_test2() */
 
+#define        SPLAT_NGROUPS   32
 /*
  * Verify the groupmember() works correctly by constructing an interesting
  * CRED() and checking that the expected gids are part of it.
@@ -188,7 +189,7 @@ splat_cred_test3(struct file *file, void *arg)
         * 1:(NGROUPS_MAX-1).  Gid 0 is explicitly avoided so we can reliably
         * test for its absence in the test cases.
         */
-       gi = groups_alloc(NGROUPS_SMALL);
+       gi = groups_alloc(SPLAT_NGROUPS);
        if (gi == NULL) {
                splat_vprint(file, SPLAT_CRED_TEST3_NAME, "Failed create "
                    "group_info for known gids: %d\n", -ENOMEM);
@@ -196,7 +197,7 @@ splat_cred_test3(struct file *file, void *arg)
                goto show_groups;
        }
 
-       for (i = 0, tmp_gid = known_gid; i < NGROUPS_SMALL; i++) {
+       for (i = 0, tmp_gid = known_gid; i < SPLAT_NGROUPS; i++) {
                splat_vprint(file, SPLAT_CRED_TEST3_NAME, "Adding gid %d "
                    "to current CRED() (%d/%d)\n", tmp_gid, i, gi->ngroups);
 #ifdef HAVE_KUIDGID_T