Package: flashcache Version: 3.1.3+git20150701-5 Severity: important Tags: patch User: [email protected] Usertags: origin-ubuntu artful ubuntu-patch
Dear Maintainer, unfortunately when fixing the compile for 4.8 (up to 4.12) kernels I missed that for some cases it is required to initialize the bi_op_flags field of dm_io_request structures to 0. I suspect the way the request is created in src/flashcache_subr.c would be ok without but for clarity and safety I added this in all cases. Not doing so lead to IOs being not written back to the backing device. This makes the driver completely unusable on those newer kernels. The supplied patch (might be merged into the compat-4.8 patch or kept seperate) is fixing this. By now I found a way of verifying the module functionality without need of additional disks. *** /tmp/tmpimJRws/bug_body In Ubuntu, the attached patch was applied to achieve the following: Fix flashcache-dkms to produce a module with 4.8..4.12 kernels which is again usable and and writes data back to the backing device. Without this the logical volume which is created can be written to but all data is lost. * Initialize bi_op_flags in dm_io_request structures (LP: #1714185). Thanks for considering the patch. -- System Information: Debian Release: stretch/sid APT prefers xenial-updates APT policy: (500, 'xenial-updates'), (500, 'xenial-security'), (500, 'xenial') Architecture: amd64 (x86_64) Foreign Architectures: i386 Kernel: Linux 4.4.0-93-generic (SMP w/8 CPU cores) Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system)
diff -Nru flashcache-3.1.3+git20150701/debian/patches/init-bi-op-flags.patch flashcache-3.1.3+git20150701/debian/patches/init-bi-op-flags.patch --- flashcache-3.1.3+git20150701/debian/patches/init-bi-op-flags.patch 1970-01-01 01:00:00.000000000 +0100 +++ flashcache-3.1.3+git20150701/debian/patches/init-bi-op-flags.patch 2017-08-30 17:05:30.000000000 +0200 @@ -0,0 +1,47 @@ +Description: Initialize bi_op_flags elements + When converting to use bi_op/bi_opf we must explicitly set bi_op_flags + in the dm_io_request structures. Otherwise it might contain garbage + that can cause bad results. +Author: Stefan Bader <[email protected]> +Forwarded: No + +Index: flashcache-3.1.3+git20150701/src/flashcache_main.c +=================================================================== +--- flashcache-3.1.3+git20150701.orig/src/flashcache_main.c ++++ flashcache-3.1.3+git20150701/src/flashcache_main.c +@@ -120,6 +120,7 @@ int dm_io_async_bvec_pl(unsigned int num + iorq.bi_rw = rw; + #else + iorq.bi_op = rw; ++ iorq.bi_op_flags = 0; + #endif + iorq.mem.type = DM_IO_PAGE_LIST; + iorq.mem.ptr.pl = pl; +@@ -148,6 +149,7 @@ int dm_io_async_bvec(unsigned int num_re + iorq.bi_rw = rw; + #else + iorq.bi_op = rw; ++ iorq.bi_op_flags = 0; + #endif + #if LINUX_VERSION_CODE >= KERNEL_VERSION(3,14,0) + iorq.mem.type = DM_IO_BIO; +Index: flashcache-3.1.3+git20150701/src/flashcache_subr.c +=================================================================== +--- flashcache-3.1.3+git20150701.orig/src/flashcache_subr.c ++++ flashcache-3.1.3+git20150701/src/flashcache_subr.c +@@ -852,6 +852,7 @@ flashcache_dm_io_async_vm(struct cache_c + .bi_rw = rw, + #else + .bi_op = rw, ++ .bi_op_flags = 0, + #endif + .mem.type = DM_IO_VMA, + .mem.ptr.vma = data, +@@ -944,6 +945,7 @@ flashcache_dm_io_sync_vm(struct cache_c + .bi_rw = rw, + #else + .bi_op = rw, ++ .bi_op_flags = 0, + #endif + .mem.type = DM_IO_VMA, + .mem.ptr.vma = data, diff -Nru flashcache-3.1.3+git20150701/debian/patches/series flashcache-3.1.3+git20150701/debian/patches/series --- flashcache-3.1.3+git20150701/debian/patches/series 2016-12-03 11:37:14.000000000 +0100 +++ flashcache-3.1.3+git20150701/debian/patches/series 2017-08-31 10:22:16.000000000 +0200 @@ -3,3 +3,4 @@ fix-build-error-on-linux-4.3.patch switch-from-ioctl-to-dm-target-messages.patch compat-4.8.patch +init-bi-op-flags.patch
