--- /dev/null
+From: Marc Dionne <marc.dionne@your-file-system.com>
+Date: Fri, 19 Dec 2014 10:11:53 -0500
+Subject: Unix CM: Avoid using stale DV in afs_StoreAllSegments
+
+It was reported in RT 131976 that on Linux some file
+corruption was observed when doing mmap writes to
+a file substantially larger than the cache size.
+
+osi_VM_StoreAllSegments drops locks and asks the OS to flush
+any dirty pages in the file 's mapping. This will trigger
+calls into our writepage op, and if the number of dirty
+cache chunks is too high (as will happen for a file larger
+than the cache size), afs_DoPartialWrite will recursively
+call afs_StoreAllSegments and some chunks will be written
+back to the server. After potentially doing this several
+times, control will return to the original afs_StoreAllSegments.
+
+At that point the data version that was stored before
+osi_VM_StoreAllSegments is no longer correct, leading to
+possible data corruption.
+
+Triggering this bug requires writing a file larger than the
+cache so that partial stores are done, and writing enough
+data to exceed the system's maximum dirty ratio and cause
+it to initiate writeback.
+
+To fix, just wait until after osi_VM_StoreAllSegments to
+look at and store the data version
+
+FIXES 131976
+
+Reviewed-on: http://gerrit.openafs.org/11644
+Tested-by: BuildBot <buildbot@rampaginggeek.com>
+Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
+(cherry picked from commit b22c586bcdf785c489009ab96cbb572181cb9b09)
+
+Change-Id: I32a2f6f32d432fe4a2e21ebd4bb278a9d7e5499f
+Reviewed-on: http://gerrit.openafs.org/11656
+Tested-by: BuildBot <buildbot@rampaginggeek.com>
+Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
+Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>
+(cherry picked from commit 013e8db33fbec8b5db4ac5a1ec94a7f5b2afbc45)
+---
+ src/afs/afs_segments.c | 10 ++++++++--
+ 1 file changed, 8 insertions(+), 2 deletions(-)
+
+diff --git a/src/afs/afs_segments.c b/src/afs/afs_segments.c
+index f407b49..1ea3311 100644
+--- a/src/afs/afs_segments.c
++++ b/src/afs/afs_segments.c
+@@ -174,8 +174,6 @@ afs_StoreAllSegments(struct vcache *avc, struct vrequest *areq,
+
+ AFS_STATCNT(afs_StoreAllSegments);
+
+- hset(oldDV, avc->f.m.DataVersion);
+- hset(newDV, avc->f.m.DataVersion);
+ hash = DVHash(&avc->f.fid);
+ foreign = (avc->f.states & CForeign);
+ dcList = (struct dcache **)osi_AllocLargeSpace(AFS_LRALLOCSIZ);
+@@ -213,6 +211,14 @@ afs_StoreAllSegments(struct vcache *avc, struct vrequest *areq,
+ /*printf("Net down in afs_StoreSegments\n");*/
+ return ENETDOWN;
+ }
++
++ /*
++ * Can't do this earlier because osi_VM_StoreAllSegments drops locks
++ * and can indirectly do some stores that increase the DV.
++ */
++ hset(oldDV, avc->f.m.DataVersion);
++ hset(newDV, avc->f.m.DataVersion);
++
+ ConvertWToSLock(&avc->lock);
+
+ /*
--- /dev/null
+From: Marc Dionne <marc.dionne@your-file-system.com>
+Date: Thu, 18 Dec 2014 07:13:46 -0500
+Subject: Linux: d_alias becomes d_u.d_alias
+MIME-Version: 1.0
+Content-Type: text/plain; charset="utf-8"
+Content-Transfer-Encoding: 8bit
+
+The fields in struct dentry are re-arranged so that d_alias
+shares space wth d_rcu inside the d_u union. Some references
+need to change from d_alias to d_u.d_alias.
+
+The kernel change was introduced for 3.19 but was also backported
+to the 3.18 stable series in 3.18.1, so this commit is required
+for 3.19 and current 3.18 kernels.
+
+Reviewed-on: http://gerrit.openafs.org/11642
+Reviewed-by: Anders Kaseorg <andersk@mit.edu>
+Reviewed-by: Michael Laß <lass@mail.uni-paderborn.de>
+Reviewed-by: Daria Brashear <shadow@your-file-system.com>
+Tested-by: BuildBot <buildbot@rampaginggeek.com>
+(cherry picked from commit d6f29679098aff171e69511823b340ccf28e5c31)
+
+Change-Id: Ifb6199aa7fa922e64540d9fad1d2d79facbb9761
+Reviewed-on: http://gerrit.openafs.org/11659
+Reviewed-by: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
+Tested-by: BuildBot <buildbot@rampaginggeek.com>
+Reviewed-by: Daria Brashear <shadow@your-file-system.com>
+Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>
+(cherry picked from commit 860764da5ee2e48a2c3f7552fad1766e19eae47f)
+---
+ acinclude.m4 | 1 +
+ src/afs/LINUX/osi_compat.h | 4 ++++
+ src/cf/linux-test4.m4 | 9 ++++++++-
+ 3 files changed, 13 insertions(+), 1 deletion(-)
+
+diff --git a/acinclude.m4 b/acinclude.m4
+index 13d70db..80a05b7 100644
+--- a/acinclude.m4
++++ b/acinclude.m4
+@@ -828,6 +828,7 @@ case $AFS_SYSNAME in *_linux* | *_umlinux*)
+ [backing-dev.h])
+ AC_CHECK_LINUX_STRUCT([cred], [session_keyring], [cred.h])
+ AC_CHECK_LINUX_STRUCT([ctl_table], [ctl_name], [sysctl.h])
++ AC_CHECK_LINUX_STRUCT([dentry], [d_u.d_alias], [dcache.h])
+ AC_CHECK_LINUX_STRUCT([dentry_operations], [d_automount], [dcache.h])
+ AC_CHECK_LINUX_STRUCT([inode], [i_alloc_sem], [fs.h])
+ AC_CHECK_LINUX_STRUCT([inode], [i_blkbits], [fs.h])
+diff --git a/src/afs/LINUX/osi_compat.h b/src/afs/LINUX/osi_compat.h
+index c500c61..15f7f69 100644
+--- a/src/afs/LINUX/osi_compat.h
++++ b/src/afs/LINUX/osi_compat.h
+@@ -37,6 +37,10 @@ typedef struct vfs_path afs_linux_path_t;
+ typedef struct path afs_linux_path_t;
+ #endif
+
++#if defined(STRUCT_DENTRY_HAS_D_U_D_ALIAS)
++# define d_alias d_u.d_alias
++#endif
++
+ #ifndef HAVE_LINUX_DO_SYNC_READ
+ static inline int
+ do_sync_read(struct file *fp, char *buf, size_t count, loff_t *offp) {
+diff --git a/src/cf/linux-test4.m4 b/src/cf/linux-test4.m4
+index b068af5..65237e2 100644
+--- a/src/cf/linux-test4.m4
++++ b/src/cf/linux-test4.m4
+@@ -723,7 +723,11 @@ AC_DEFUN([LINUX_D_ALIAS_IS_HLIST], [
+ [#include <linux/fs.h>],
+ [struct dentry *d = NULL;
+ struct hlist_node *hn = NULL;
+- d->d_alias = *hn;],
++ #if defined(STRUCT_DENTRY_HAS_D_U_D_ALIAS)
++ d->d_u.d_alias = *hn;
++ #else
++ d->d_alias = *hn;
++ #endif],
+ [D_ALIAS_IS_HLIST],
+ [define if dentry->d_alias is an hlist],
+ [])
+@@ -737,6 +741,9 @@ AC_DEFUN([LINUX_HLIST_ITERATOR_NO_NODE], [
+ #include <linux/fs.h>],
+ [struct dentry *d = NULL, *cur;
+ struct inode *ip;
++ #if defined(STRUCT_DENTRY_HAS_D_U_D_ALIAS)
++ # define d_alias d_u.d_alias
++ #endif
+ hlist_for_each_entry(cur, &ip->i_dentry, d_alias) { }
+ ],
+ [HLIST_ITERATOR_NO_NODE],
projects / packages / o / openafs.git / commitdiff