From: Marc Dionne <marc.c.dionne@gmail.com>
Date: Sat, 8 Nov 2008 16:13:59 +0000 (+0000)
Subject: DEVEL15-linux-disable-readahad-20081108
X-Git-Tag: openafs-devel-1_5_55~3
X-Git-Url: http://git.openafs.org/?p=openafs.git;a=commitdiff_plain;h=856e99dcdfee3fac6d4ed8e001cd82d9d136bdea;hp=230c54bef4cdffa1b1412f9ae2758e992e10faea

DEVEL15-linux-disable-readahad-20081108

LICENSE IPL10
FIXES 123604

The code has long contained a backing_dev_info structure, but it
was never attached to anything.  Initialize its use properly with
bdi_init, and attach it to i_mapping for every newly filled inode.
bdi_init and bdi_destroy are needed for proper initialization of
some percpu counters, otherwise we get some oopses.


(cherry picked from commit 18e78d91e78e541fce6c9295919946af0744aa7e)
---

diff --git a/acinclude.m4 b/acinclude.m4
index 325d3dc..4988cc4 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -829,6 +829,7 @@ case $AFS_SYSNAME in *_linux* | *_umlinux*)
 		 LINUX_EXPORTS_FIND_TASK_BY_PID
 		 LINUX_EXPORTS_PROC_ROOT_FS
                  LINUX_HAVE_CURRENT_KERNEL_TIME
+                 LINUX_HAVE_BDI_INIT
                  LINUX_KMEM_CACHE_INIT
 		 LINUX_HAVE_KMEM_CACHE_T
 		 LINUX_KMEM_CACHE_CREATE_TAKES_DTOR
diff --git a/src/afs/LINUX/osi_vfsops.c b/src/afs/LINUX/osi_vfsops.c
index b2d906c..92dc336 100644
--- a/src/afs/LINUX/osi_vfsops.c
+++ b/src/afs/LINUX/osi_vfsops.c
@@ -149,6 +149,9 @@ afs_read_super(struct super_block *sb, void *data, int silent)
 #if defined(AFS_LINUX26_ENV) && !defined(AFS_NONFSTRANS)
     sb->s_export_op = &afs_export_ops;
 #endif
+#if defined(HAVE_BDI_INIT)
+    bdi_init(&afs_backing_dev_info);
+#endif
 #if defined(MAX_NON_LFS)
 #ifdef AFS_64BIT_CLIENT
 #if !defined(MAX_LFS_FILESIZE)
@@ -400,6 +403,9 @@ afs_put_super(struct super_block *sbp)
 #endif
 
     osi_linux_verify_alloced_memory();
+#if defined(HAVE_BDI_INIT)
+    bdi_destroy(&afs_backing_dev_info);
+#endif
     AFS_GUNLOCK();
 
     sbp->s_dev = 0;
diff --git a/src/afs/LINUX/osi_vnodeops.c b/src/afs/LINUX/osi_vnodeops.c
index 5e7a62c..7a5a26e 100644
--- a/src/afs/LINUX/osi_vnodeops.c
+++ b/src/afs/LINUX/osi_vnodeops.c
@@ -53,6 +53,7 @@ RCSID
 #if defined(AFS_LINUX26_ENV)
 #define LockPage(pp) lock_page(pp)
 #define UnlockPage(pp) unlock_page(pp)
+extern struct backing_dev_info afs_backing_dev_info;
 #endif
 
 extern struct vcache *afs_globalVp;
@@ -2231,6 +2232,7 @@ afs_fill_inode(struct inode *ip, struct vattr *vattr)
     if (vattr)
 	vattr2inode(ip, vattr);
 
+    ip->i_mapping->backing_dev_info = &afs_backing_dev_info;
 /* Reset ops if symlink or directory. */
     if (S_ISREG(ip->i_mode)) {
 	ip->i_op = &afs_file_iops;
diff --git a/src/cf/linux-test4.m4 b/src/cf/linux-test4.m4
index af278de..1d95461 100644
--- a/src/cf/linux-test4.m4
+++ b/src/cf/linux-test4.m4
@@ -1092,3 +1092,15 @@ AC_DEFUN([LINUX_SEMAPHORE_H_EXISTS], [
     AC_DEFINE([LINUX_SEMAPHORE_H], 1, [define if linux/semaphore.h exists])
   fi])
 
+AC_DEFUN([LINUX_HAVE_BDI_INIT], [
+  AC_MSG_CHECKING([for linux bdi_init()])
+  AC_CACHE_VAL([ac_cv_linux_bdi_init], [
+    AC_TRY_KBUILD(
+[#include <linux/backing-dev.h>],
+[bdi_init(NULL);],
+      ac_cv_linux_bdi_init=yes,
+      ac_cv_linux_bdi_init=no)])
+  AC_MSG_RESULT($ac_cv_linux_bdi_init)
+  if test "x$ac_cv_linux_bdi_init" = "xyes"; then
+    AC_DEFINE([HAVE_BDI_INIT], 1, [define if your kernel has a bdi_init()])
+  fi])