https://bugzilla.kernel.org/show_bug.cgi?id=15579 --- Comment #9 from Andreas Beckmann <kernel-bugs@xxxxxxxxxxxx> 2010-03-29 08:36:38 --- (In reply to comment #4) > Just for what it's worth, I've had trouble reproducing this on another brand of > SSD... something like this (don't let the xfs_io throw you; it's just a > convenient way to generate the IO). I did this on a 512M filesystem. With some small modifications I can reproduce this every time: I do two iterations of truncating + writing the output. Seems to happen in the second write only. You can skip the reading, not neccessary. N=236 ist the smallest N where the problem occurs, N=253 the maximum number of files fitting on the file system. ./find-zeroes is my tool to check for "0x00 holes" mkfs options: -m 0 -T largefile4 #!/bin/bash SCRATCH_MNT=/mnt/scratch N=253 #rm -f $SCRATCH_MNT/* #touch $SCRATCH_MNT/outputfile #xfs_io -F -c "pwrite 0 ${N}m" $SCRATCH_MNT/outputfile &>/dev/null #xfs_io -F -c "pwrite ${N}M ${N}m" $SCRATCH_MNT/outputfile &>/dev/null #./find-zeroes $SCRATCH_MNT/outputfile rm -f $SCRATCH_MNT/* touch $SCRATCH_MNT/outputfile # Create several large-ish files for I in `seq 1 $N`; do xfs_io -F -f -c "pwrite 0 2m" $SCRATCH_MNT/file$I &>/dev/null done # reread the last bit of each, just for kicks, and truncate off 1m for I in `seq 1 $N`; do xfs_io -F -c "pread 1m 1m" $SCRATCH_MNT/file$I &>/dev/null xfs_io -F -c "truncate 1m" $SCRATCH_MNT/file$I done # Append the outputfile xfs_io -F -c "pwrite 0 ${N}m" $SCRATCH_MNT/outputfile &>/dev/null # reread the last bit of each, just for kicks, and truncate off 1m for I in `seq 1 $N`; do xfs_io -F -c "pread 0m 1m" $SCRATCH_MNT/file$I &>/dev/null xfs_io -F -c "truncate 0m" $SCRATCH_MNT/file$I done # Append the outputfile xfs_io -F -c "pwrite ${N}M ${N}m" $SCRATCH_MNT/outputfile &>/dev/null ./find-zeroes $SCRATCH_MNT/outputfile $ ./trash-ext4-discard at 246800384 length 18489344 size 511950848 zeroes 18489344 $ ./trash-ext4-discard at 246808576 length 18481152 size 511950848 zeroes 18481152 $ ./trash-ext4-discard at 246857728 length 18432000 size 511848448 zeroes 18432000 $ ./trash-ext4-discard at 246640640 length 18649088 size 512086016 zeroes 18649088 $ ./trash-ext4-discard at 246800384 length 18489344 size 511959040 zeroes 18489344 actually this is enough: # Create several large-ish files for I in `seq 1 $N`; do xfs_io -F -f -c "pwrite 0 1m" $SCRATCH_MNT/file$I &>/dev/null done # Append the outputfile xfs_io -F -c "pwrite 0 ${N}m" $SCRATCH_MNT/outputfile &>/dev/null # truncate all for I in `seq 1 $N`; do xfs_io -F -c "truncate 0m" $SCRATCH_MNT/file$I done # Append the outputfile xfs_io -F -c "pwrite ${N}M ${N}m" $SCRATCH_MNT/outputfile &>/dev/null $ ./trash-ext4-discard2 at 228061184 length 37228544 size 530579456 zeroes 37228544 -- 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
