https://bugzilla.kernel.org/show_bug.cgi?id=43354 Summary: Corruption on a small loopback ext4 file system with Linux 3.4 Product: File System Version: 2.5 Kernel Version: 3.4.1 Platform: All OS/Version: Linux Tree: Mainline Status: NEW Severity: high Priority: P1 Component: ext4 AssignedTo: fs_ext4@xxxxxxxxxxxxxxxxxxxx ReportedBy: alecm@xxxxxxx Regression: Yes With Linux 3.4, I am getting major corruption on a loopback ext4 filesystem: parts of files are randomly inserted into other files. Below are steps to reproduce - I've been able to reproduce this on two different systems. Both have ext4 root, using a plain kernel.org 3.4.1 kernel. The problem does not reproduce when switching back to Linux 3.3.6. If you need any additional info, I'll be happy to provide it. # uname -r 3.4.1 # dd if=/dev/zero of=tree.ext4 bs=1M count=512 512+0 records in 512+0 records out 536870912 bytes (537 MB) copied, 0.589387 s, 911 MB/s # mkfs.ext4 -T small -N 200000 tree.ext4 mke2fs 1.42.3 (14-May-2012) tree.ext4 is not a block special device. Proceed anyway? (y,n) y Discarding device blocks: done Filesystem label= OS type: Linux Block size=1024 (log=0) Fragment size=1024 (log=0) Stride=0 blocks, Stripe width=0 blocks 200192 inodes, 524288 blocks 26214 blocks (5.00%) reserved for the super user First data block=1 Maximum filesystem blocks=67633152 64 block groups 8192 blocks per group, 8192 fragments per group 3128 inodes per group Superblock backups stored on blocks: 8193, 24577, 40961, 57345, 73729, 204801, 221185, 401409 Allocating group tables: done Writing inode tables: done Creating journal (16384 blocks): done Writing superblocks and filesystem accounting information: done # mkdir tree # mount -o loop tree.ext4 tree # tar xaf portage-20120607.tar.xz -C tree # find tree -type f -exec sha1sum {} \; > checksums # umount tree # sync # echo 3 > /proc/sys/vm/drop_caches # important! everything will seem fine otherwise # fsck.ext4 -f tree.ext4 e2fsck 1.42.3 (14-May-2012) Pass 1: Checking inodes, blocks, and sizes Pass 2: Checking directory structure Pass 3: Checking directory connectivity Pass 4: Checking reference counts Pass 5: Checking group summary information tree.ext4: 183722/200192 files (0.0% non-contiguous), 402575/524288 blocks # mount -o loop tree.ext4 tree # sha1sum --check --quiet checksums tree/portage/net-firewall/conntrack-tools/ChangeLog: FAILED tree/portage/net-firewall/conntrack-tools/files/conntrackd.initd-r1: FAILED tree/portage/net-firewall/nufw/ChangeLog: FAILED ... -- Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are watching the assignee of the bug. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
