https://bugzilla.kernel.org/show_bug.cgi?id=195561 Bug ID: 195561 Summary: Suspicious persistent EXT4-fs error (device sda1): ext4_validate_block_bitmap:395: [Proc] bg 17: block 557056: invalid block bitmap Product: File System Version: 2.5 Kernel Version: 4.4 to 4.11 Hardware: x86-64 OS: Linux Tree: Mainline Status: NEW Severity: high Priority: P1 Component: ext4 Assignee: fs_ext4@xxxxxxxxxxxxxxxxxxxx Reporter: issor.oruam@xxxxxxxxx Regression: No Created attachment 255963 --> https://bugzilla.kernel.org/attachment.cgi?id=255963&action=edit dmesg on Phy SATA HDD1 While testing Android 7.1 nougat-x86 x86_64 several android-x86 community members noticed the occurence of EXT4 partition remount RO which causes a bootloop with continuous kernel panic on Android 7.x which requires to reinstall Android OS image on EXT4 partitions. When looking in logcat we would just see that everything stops working because of the partion has been remounted in Read-Only. Looking at dmesg output we see the following attached three logs for three test cases: Physical Sata HDD 1 Physical Sata HDD 2 Virtualbox vdi 3 January, 14th (ASUS motherboard with physical SATA HDD n.1) [ 842.760419] EXT4-fs error (device sda1): ext4_validate_block_bitmap:395: comm Binder:1454_E: bg 17: block 557056: invalid block bitmap [ 842.873601] Aborting journal on device sda1-8. [ 842.908371] EXT4-fs (sda1): Remounting filesystem read-only [ 842.923638] EXT4-fs error (device sda1) in ext4_do_update_inode:4679: Journal has aborted March, 25th (ASUS motherboard with physical SATA HDD n.2, different from n.1) [ 1510.269945] EXT4-fs error (device sda1): ext4_validate_block_bitmap:395: comm main: bg 17: block 557056: invalid block bitmap [ 1510.285464] Aborting journal on device sda1-8. [ 1510.301047] EXT4-fs (sda1): Remounting filesystem read-only [ 1510.323400] EXT4-fs error (device sda1) in ext4_do_update_inode:4679: Journal has aborted April, 25th (VirtualBox VM with vdi vitual drive n.3, different from n.1 and n.2) [ 1510.269945] EXT4-fs error (device sda1): ext4_validate_block_bitmap:395: comm main: bg 17: block 557056: invalid block bitmap [ 1510.285464] Aborting journal on device sda1-8. [ 1510.301047] EXT4-fs (sda1): Remounting filesystem read-only [ 1510.323400] EXT4-fs error (device sda1) in ext4_do_update_inode:4679: Journal has aborted What they all have in common is the bg and block which happen to be exactly the same, no matter how many attempts on different physical or virtual HDDs. The problem is intermittent, but happens quite frequently during initial Google Play updates, so it may become a show stopper for Android and a series of different OSes. One catalyzer to let the issue happen is multithreading/processes forking which Androdi 7.x uses far more than 6.0. Android 6.0 has no issue with the same kernels. In my understanding there may be a sort block/bg locking issue leading to concurrent write and validation of bitmaps Another possible concurring root cause may be 64 bit kernel build, as on virtualbox the issue is systematic with 64 bit build and I've never saw it with 32bit builds. This would be coherent with statements in [1] Doing some research I found reference of this problem in different websites [1], [2] and [3] [1] https://community.nxp.com/thread/447695 [2] https://jira.hpdd.intel.com/browse/LU-1026 (at the end EXT4 patch is mentioned) [3] https://github.com/tweag/lustre/blob/master/ldiskfs/kernel_patches/patches/rhel7/ext4-corrupted-inode-block-bitmaps-handling-patches.patch The attached HACK workaround can avoid the problem, tested on top of kernel 4.4.62 but it's not a solution as it uses ext4_warning() instead of ext4_error() and tricks the callers by pretending there was no error, we could even put a check on "bg == 16 && block == 557056" but it would still be a hack to workaround a bug in EXT4 bitmap validation code. It is also confirmed that kernel 4.9, 4.10 and 4.11 are also affected. Mauro -- You are receiving this mail because: You are watching the assignee of the bug.
