Public bug reported: Hi,
I found a bug that crashes the machine if you create a bcache where the caching device size is bigger than backing device. This case may happen if you create a bcache with a plan to add a bigger disk/partition/raid later to it. To reproduce it follow this steps: start a vm with utopic-amd64-desktop iso, it must have 2 disks, one of 16G and on of 8G apt-get update && apt-get install bcache-tools /dev/sda is 16G caching device /dev/sdb is 8G backing device make-bcache --write-back --discard -C /dev/sda -B /dev/sdb now the machine is hanged. if you reboot and reinstall bcache-tools the bcache device has been created ************************************ bcache-super-show -f /dev/sda: ============================== sb.magic ok sb.first_sector 8 [match] sb.csum 45C96B38A79275A7 [match] sb.version 0 [cache device] dev.label (empty) dev.uuid 155ab65e-e74a-4ca8-91da-467ef696db63 dev.sectors_per_block 1 dev.sectors_per_bucket 1024 dev.cache.first_sector 1024 dev.cache.cache_sectors 33553408 dev.cache.total_sectors 33554432 dev.cache.ordered no dev.cache.discard yes dev.cache.pos 0 dev.cache.replacement 0 [lru] cset.uuid bcaa2595-bbc8-43a7-8c44-5d0aca0f3fc8 ***************************************************** bcache-super-show /dev/sdb: ============================================= sb.magic ok sb.first_sector 8 [match] sb.csum F37A1BB08A7F5DE7 [match] sb.version 1 [backing device] dev.label (empty) dev.uuid 341f1c83-1797-4157-aa9e-524107db5606 dev.sectors_per_block 1 dev.sectors_per_bucket 1024 dev.data.first_sector 16 dev.data.cache_mode 1 [writeback] dev.data.cache_state 0 [detached] cset.uuid bcaa2595-bbc8-43a7-8c44-5d0aca0f3fc8 ***************************************************** you can format it: mkfs.ext4 /dev/bcache0 Rejet des blocs de périphérique : complété Creating filesystem with 2097150 4k blocks and 524288 inodes Filesystem UUID: b99a09de-3a92-4a44-82cd-29f75f8bf0c9 Superblocs de secours stockés sur les blocs : 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632 Allocation des tables de groupe : complété Écriture des tables d'i-noeuds : complété Création du journal (32768 blocs) : complété Écriture des superblocs et de l'information de comptabilité du système de fichiers : restarting the format gave me an other bug (X.org crashing): free from cli: total used free shared buffers cached Mem: 1017168 814040 203128 195568 91264 513064 -/+ buffers/cache: 209712 807456 Swap: 0 0 0 tail /var/log/syslog: [ 568.016481] [ 4983] 0 4983 3332 121 11 0 0 mdadm [ 568.016483] [ 5259] 0 5259 6703 300 19 0 0 mkfs.ext4 [ 568.016484] Out of memory: Kill process 1947 (Xorg) score 38 or sacrifice child [ 568.016485] Killed process 1947 (Xorg) total-vm:313160kB, anon-rss:35976kB, file-rss:4232kB [ 568.707107] systemd-logind[1396]: Failed to start unit [email protected]: Unknown unit: [email protected] [ 568.707113] systemd-logind[1396]: Failed to start user service: Unknown unit: [email protected] [ 568.709876] systemd-logind[1396]: New session c8 of user lightdm. [ 568.709890] systemd-logind[1396]: Linked /tmp/.X11-unix/X0 to /run/user/112/X11-display. You can unregister the bcache device: [ 830.811150] bcache: cached_dev_detach_finish() Caching disabled for sdb [ 830.949898] bcache: cache_set_free() Cache set bcaa2595-bbc8-43a7-8c44-5d0aca0f3fc8 unregistered ** Affects: linux (Ubuntu) Importance: Undecided Status: New ** Description changed: Hi, I found a bug that crashes the machine if you create a bcache where the - cahcing device size is bigger than backing device. + caching device size is bigger than backing device. + + This case may happen if you create a bcache with a plan to add a bigger + disk/partition/raid later to it. To reproduce it follow this steps: start a vm with utopic-amd64-desktop iso, it must have 2 disks, one of 16G and on of 8G apt-get update && apt-get install bcache-tools /dev/sda is 16G caching device /dev/sdb is 8G backing device make-bcache --write-back --discard -C /dev/sda -B /dev/sdb now the machine is hanged. - if you reboot and reinstall bcache-tools + if you reboot and reinstall bcache-tools the bcache device has been created ************************************ bcache-super-show -f /dev/sda: ============================== sb.magic ok sb.first_sector 8 [match] sb.csum 45C96B38A79275A7 [match] sb.version 0 [cache device] dev.label (empty) dev.uuid 155ab65e-e74a-4ca8-91da-467ef696db63 dev.sectors_per_block 1 dev.sectors_per_bucket 1024 dev.cache.first_sector 1024 dev.cache.cache_sectors 33553408 dev.cache.total_sectors 33554432 dev.cache.ordered no dev.cache.discard yes dev.cache.pos 0 dev.cache.replacement 0 [lru] cset.uuid bcaa2595-bbc8-43a7-8c44-5d0aca0f3fc8 ***************************************************** bcache-super-show /dev/sdb: ============================================= sb.magic ok sb.first_sector 8 [match] sb.csum F37A1BB08A7F5DE7 [match] sb.version 1 [backing device] dev.label (empty) dev.uuid 341f1c83-1797-4157-aa9e-524107db5606 dev.sectors_per_block 1 dev.sectors_per_bucket 1024 dev.data.first_sector 16 dev.data.cache_mode 1 [writeback] dev.data.cache_state 0 [detached] cset.uuid bcaa2595-bbc8-43a7-8c44-5d0aca0f3fc8 ***************************************************** you can format it: mkfs.ext4 /dev/bcache0 - Rejet des blocs de périphérique : complété + Rejet des blocs de périphérique : complété Creating filesystem with 2097150 4k blocks and 524288 inodes Filesystem UUID: b99a09de-3a92-4a44-82cd-29f75f8bf0c9 - Superblocs de secours stockés sur les blocs : - 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632 + Superblocs de secours stockés sur les blocs : + 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632 - Allocation des tables de groupe : complété - Écriture des tables d'i-noeuds : complété + Allocation des tables de groupe : complété + Écriture des tables d'i-noeuds : complété Création du journal (32768 blocs) : complété Écriture des superblocs et de l'information de comptabilité du système de fichiers : restarting the format gave me an other bug (X.org crashing): free from cli: - total used free shared buffers cached + total used free shared buffers cached Mem: 1017168 814040 203128 195568 91264 513064 -/+ buffers/cache: 209712 807456 Swap: 0 0 0 tail /var/log/syslog: [ 568.016481] [ 4983] 0 4983 3332 121 11 0 0 mdadm [ 568.016483] [ 5259] 0 5259 6703 300 19 0 0 mkfs.ext4 [ 568.016484] Out of memory: Kill process 1947 (Xorg) score 38 or sacrifice child [ 568.016485] Killed process 1947 (Xorg) total-vm:313160kB, anon-rss:35976kB, file-rss:4232kB [ 568.707107] systemd-logind[1396]: Failed to start unit [email protected]: Unknown unit: [email protected] [ 568.707113] systemd-logind[1396]: Failed to start user service: Unknown unit: [email protected] [ 568.709876] systemd-logind[1396]: New session c8 of user lightdm. [ 568.709890] systemd-logind[1396]: Linked /tmp/.X11-unix/X0 to /run/user/112/X11-display. You can unregister the bcache device: [ 830.811150] bcache: cached_dev_detach_finish() Caching disabled for sdb [ 830.949898] bcache: cache_set_free() Cache set bcaa2595-bbc8-43a7-8c44-5d0aca0f3fc8 unregistered -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1377130 Title: Crash at creation of bcache if caching size > backing size Status in “linux” package in Ubuntu: New Bug description: Hi, I found a bug that crashes the machine if you create a bcache where the caching device size is bigger than backing device. This case may happen if you create a bcache with a plan to add a bigger disk/partition/raid later to it. To reproduce it follow this steps: start a vm with utopic-amd64-desktop iso, it must have 2 disks, one of 16G and on of 8G apt-get update && apt-get install bcache-tools /dev/sda is 16G caching device /dev/sdb is 8G backing device make-bcache --write-back --discard -C /dev/sda -B /dev/sdb now the machine is hanged. if you reboot and reinstall bcache-tools the bcache device has been created ************************************ bcache-super-show -f /dev/sda: ============================== sb.magic ok sb.first_sector 8 [match] sb.csum 45C96B38A79275A7 [match] sb.version 0 [cache device] dev.label (empty) dev.uuid 155ab65e-e74a-4ca8-91da-467ef696db63 dev.sectors_per_block 1 dev.sectors_per_bucket 1024 dev.cache.first_sector 1024 dev.cache.cache_sectors 33553408 dev.cache.total_sectors 33554432 dev.cache.ordered no dev.cache.discard yes dev.cache.pos 0 dev.cache.replacement 0 [lru] cset.uuid bcaa2595-bbc8-43a7-8c44-5d0aca0f3fc8 ***************************************************** bcache-super-show /dev/sdb: ============================================= sb.magic ok sb.first_sector 8 [match] sb.csum F37A1BB08A7F5DE7 [match] sb.version 1 [backing device] dev.label (empty) dev.uuid 341f1c83-1797-4157-aa9e-524107db5606 dev.sectors_per_block 1 dev.sectors_per_bucket 1024 dev.data.first_sector 16 dev.data.cache_mode 1 [writeback] dev.data.cache_state 0 [detached] cset.uuid bcaa2595-bbc8-43a7-8c44-5d0aca0f3fc8 ***************************************************** you can format it: mkfs.ext4 /dev/bcache0 Rejet des blocs de périphérique : complété Creating filesystem with 2097150 4k blocks and 524288 inodes Filesystem UUID: b99a09de-3a92-4a44-82cd-29f75f8bf0c9 Superblocs de secours stockés sur les blocs : 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632 Allocation des tables de groupe : complété Écriture des tables d'i-noeuds : complété Création du journal (32768 blocs) : complété Écriture des superblocs et de l'information de comptabilité du système de fichiers : restarting the format gave me an other bug (X.org crashing): free from cli: total used free shared buffers cached Mem: 1017168 814040 203128 195568 91264 513064 -/+ buffers/cache: 209712 807456 Swap: 0 0 0 tail /var/log/syslog: [ 568.016481] [ 4983] 0 4983 3332 121 11 0 0 mdadm [ 568.016483] [ 5259] 0 5259 6703 300 19 0 0 mkfs.ext4 [ 568.016484] Out of memory: Kill process 1947 (Xorg) score 38 or sacrifice child [ 568.016485] Killed process 1947 (Xorg) total-vm:313160kB, anon-rss:35976kB, file-rss:4232kB [ 568.707107] systemd-logind[1396]: Failed to start unit [email protected]: Unknown unit: [email protected] [ 568.707113] systemd-logind[1396]: Failed to start user service: Unknown unit: [email protected] [ 568.709876] systemd-logind[1396]: New session c8 of user lightdm. [ 568.709890] systemd-logind[1396]: Linked /tmp/.X11-unix/X0 to /run/user/112/X11-display. You can unregister the bcache device: [ 830.811150] bcache: cached_dev_detach_finish() Caching disabled for sdb [ 830.949898] bcache: cache_set_free() Cache set bcaa2595-bbc8-43a7-8c44-5d0aca0f3fc8 unregistered To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1377130/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
