LU-20 osd-ldiskfs: Make readonly patches optional

If CONFIG_KALLSYMS is enabled, see if there are dev_set/check_rdonly
functions present and use them if so.
Otherwise assume the functionality is unavailable.

This should allow using osd_ldiskfs module on both patched and
unpatched kernels with no modifications thanks to weak updates.

Change-Id: I274db77cf76abc63ad6a5643a98c521778f294b3
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Reviewed-on: https://review.whamcloud.com/27549
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>

diff --git a/lustre/autoconf/lustre-core.m4 b/lustre/autoconf/lustre-core.m4
index c6f2377..b9b8a6d 100644 (file)
--- a/lustre/autoconf/lustre-core.m4
+++ b/lustre/autoconf/lustre-core.m4
@@ -74,19 +74,6 @@ AC_CHECK_FUNCS([name_to_handle_at],
 ]) # LC_GLIBC_SUPPORT_FHANDLES
 
 #
 ]) # LC_GLIBC_SUPPORT_FHANDLES
 
 #

-# LC_FUNC_DEV_SET_RDONLY
-#
-# check whether dev_set_rdonly is exported.  This is needed until we
-# have another mechanism to fence IO from the underlying device.
-#
-AC_DEFUN([LC_FUNC_DEV_SET_RDONLY], [
-LB_CHECK_EXPORT([dev_set_rdonly], [block/ll_rw_block.c block/blk-core.c],
-       [AC_DEFINE(HAVE_DEV_SET_RDONLY, 1,
-               [kernel exports dev_set_rdonly])],
-       [AC_MSG_WARN([kernel missing dev_set_rdonly patch for testing])])
-]) # LC_FUNC_DEV_SET_RDONLY
-
-#

 # LC_STACK_SIZE
 #
 # Ensure the stack size is at least 8k in Lustre server (all kernels)
 # LC_STACK_SIZE
 #
 # Ensure the stack size is at least 8k in Lustre server (all kernels)


@@ -2694,7 +2681,6 @@ AC_DEFUN([LC_PROG_LINUX], [
 
        #
        AS_IF([test "x$enable_server" != xno], [
 
        #
        AS_IF([test "x$enable_server" != xno], [

-               LC_FUNC_DEV_SET_RDONLY

                LC_STACK_SIZE
                LC_QUOTA64
                LC_QUOTA_CONFIG
                LC_STACK_SIZE
                LC_QUOTA64
                LC_QUOTA_CONFIG

diff --git a/lustre/osd-ldiskfs/osd_handler.c b/lustre/osd-ldiskfs/osd_handler.c
index c0030b2..4e98210 100644 (file)
--- a/lustre/osd-ldiskfs/osd_handler.c
+++ b/lustre/osd-ldiskfs/osd_handler.c
@@ -2161,44 +2161,47 @@ static int osd_commit_async(const struct lu_env *env,
         RETURN(s->s_op->sync_fs(s, 0));
 }
 
         RETURN(s->s_op->sync_fs(s, 0));
 }
 

+/* Our own copy of the set readonly functions if present, or NU if not. */
+static int (*priv_dev_set_rdonly)(struct block_device *bdev);
+static int (*priv_dev_check_rdonly)(struct block_device *bdev);
+/* static int (*priv_dev_clear_rdonly)(struct block_device *bdev); */
+

 /*
  * Concurrency: shouldn't matter.
  */
 /*
  * Concurrency: shouldn't matter.
  */

-

 static int osd_ro(const struct lu_env *env, struct dt_device *d)
 {
        struct super_block *sb = osd_sb(osd_dt_dev(d));
        struct block_device *dev = sb->s_bdev;
 static int osd_ro(const struct lu_env *env, struct dt_device *d)
 {
        struct super_block *sb = osd_sb(osd_dt_dev(d));
        struct block_device *dev = sb->s_bdev;

-#ifdef HAVE_DEV_SET_RDONLY
-       struct block_device *jdev = LDISKFS_SB(sb)->journal_bdev;
-       int rc = 0;
-#else

        int rc = -EOPNOTSUPP;
        int rc = -EOPNOTSUPP;

-#endif

        ENTRY;
 
        ENTRY;
 

-#ifdef HAVE_DEV_SET_RDONLY
-       CERROR("*** setting %s read-only ***\n", osd_dt_dev(d)->od_svname);
+       if (priv_dev_set_rdonly) {
+               struct block_device *jdev = LDISKFS_SB(sb)->journal_bdev;

 
 

-       if (sb->s_op->freeze_fs) {
-               rc = sb->s_op->freeze_fs(sb);
-               if (rc)
-                       goto out;
-       }
+               rc = 0;
+               CERROR("*** setting %s read-only ***\n",
+                      osd_dt_dev(d)->od_svname);

 
 

-       if (jdev && (jdev != dev)) {
-               CDEBUG(D_IOCTL | D_HA, "set journal dev %lx rdonly\n",
-                      (long)jdev);
-               dev_set_rdonly(jdev);
-       }
-       CDEBUG(D_IOCTL | D_HA, "set dev %lx rdonly\n", (long)dev);
-       dev_set_rdonly(dev);
+               if (sb->s_op->freeze_fs) {
+                       rc = sb->s_op->freeze_fs(sb);
+                       if (rc)
+                               goto out;
+               }
+
+               if (jdev && (jdev != dev)) {
+                       CDEBUG(D_IOCTL | D_HA, "set journal dev %lx rdonly\n",
+                              (long)jdev);
+                       priv_dev_set_rdonly(jdev);
+               }
+               CDEBUG(D_IOCTL | D_HA, "set dev %lx rdonly\n", (long)dev);
+               priv_dev_set_rdonly(dev);

 
 

-       if (sb->s_op->unfreeze_fs)
-               sb->s_op->unfreeze_fs(sb);
+               if (sb->s_op->unfreeze_fs)
+                       sb->s_op->unfreeze_fs(sb);
+       }

 
 out:
 
 out:

-#endif

        if (rc)
                CERROR("%s: %lx CANNOT BE SET READONLY: rc = %d\n",
                       osd_dt_dev(d)->od_svname, (long)dev, rc);
        if (rc)
                CERROR("%s: %lx CANNOT BE SET READONLY: rc = %d\n",
                       osd_dt_dev(d)->od_svname, (long)dev, rc);


@@ -6968,25 +6971,23 @@ static int osd_mount(const struct lu_env *env,
        }
 
        if (lmd_flags & LMD_FLG_DEV_RDONLY) {
        }
 
        if (lmd_flags & LMD_FLG_DEV_RDONLY) {

-#ifdef HAVE_DEV_SET_RDONLY
-               dev_set_rdonly(osd_sb(o)->s_bdev);
-               o->od_dt_dev.dd_rdonly = 1;
-               LCONSOLE_WARN("%s: set dev_rdonly on this device\n", name);
-#else
-               LCONSOLE_WARN("%s: not support dev_rdonly on this device",
-                             name);
-
-               GOTO(out_mnt, rc = -EOPNOTSUPP);
-#endif
-       } else {
-#ifdef HAVE_DEV_SET_RDONLY
-               if (dev_check_rdonly(osd_sb(o)->s_bdev)) {
-                       CERROR("%s: underlying device %s is marked as "
-                              "read-only. Setup failed\n", name, dev);
+               if (priv_dev_set_rdonly) {
+                       priv_dev_set_rdonly(osd_sb(o)->s_bdev);
+                       o->od_dt_dev.dd_rdonly = 1;
+                       LCONSOLE_WARN("%s: set dev_rdonly on this device\n",
+                                     name);
+               } else {
+                       LCONSOLE_WARN("%s: not support dev_rdonly on this device",
+                                     name);

 
 

-                       GOTO(out_mnt, rc = -EROFS);
+                       GOTO(out_mnt, rc = -EOPNOTSUPP);

                }
                }

-#endif
+       } else if (priv_dev_check_rdonly &&
+                  priv_dev_check_rdonly(osd_sb(o)->s_bdev)) {
+               CERROR("%s: underlying device %s is marked as "
+                      "read-only. Setup failed\n", name, dev);
+
+               GOTO(out_mnt, rc = -EROFS);

        }
 
        if (!LDISKFS_HAS_COMPAT_FEATURE(o->od_mnt->mnt_sb,
        }
 
        if (!LDISKFS_HAS_COMPAT_FEATURE(o->od_mnt->mnt_sb,


@@ -7404,6 +7405,13 @@ static int __init osd_init(void)
        if (rc)
                return rc;
 
        if (rc)
                return rc;
 

+#ifdef CONFIG_KALLSYMS
+       priv_dev_set_rdonly = (void *)kallsyms_lookup_name("dev_set_rdonly");
+       priv_dev_check_rdonly = (void *)kallsyms_lookup_name("dev_check_rdonly");
+       /* Clear readonly is unused at this time */
+       /*priv_dev_clear_rdonly = (void *)kallsyms_lookup_name("dev_clear_rdonly");*/
+#endif
+

        rc = class_register_type(&osd_obd_device_ops, NULL, true,
                                 lprocfs_osd_module_vars,
                                 LUSTRE_OSD_LDISKFS_NAME, &osd_device_type);
        rc = class_register_type(&osd_obd_device_ops, NULL, true,
                                 lprocfs_osd_module_vars,
                                 LUSTRE_OSD_LDISKFS_NAME, &osd_device_type);