Hi Xiao, On 24/12/20 11:18 pm, Xiao Ni wrote:> The root cause is found. Now we use a similar way with raid0 to handle discard request > for raid10. Because the discard region is very big, we can calculate the > start/end address > for each disk. Then we can submit the discard request to each disk. But for > raid10, it has > copies. For near layout, if the discard request doesn't align with chunk > size, we calculate > a start_disk_offset. Now we only use start_disk_offset for the first disk, > but it should be > used for the near copies disks too.
Thanks for finding the root cause and making a patch that corrects the offset addresses for multiple disks! > > [ 789.709501] discard bio start : 70968, size : 191176 > [ 789.709507] first stripe index 69, start disk index 0, start disk offset > 70968 > [ 789.709509] last stripe index 256, end disk index 0, end disk offset 262144 > [ 789.709511] disk 0, dev start : 70968, dev end : 262144 > [ 789.709515] disk 1, dev start : 70656, dev end : 262144 > > For example, in this test case, it has 2 near copies. The start_disk_offset > for the first disk is 70968. > It should use the same offset address for second disk. But it uses the start > address of this chunk. > It discard more region. The patch in the attachment can fix this problem. It > split the region that > doesn't align with chunk size. Just wondering, what is the current status of the patchset? Is there anything that I can do to help? > > There is another problem. The stripe size should be calculated differently > for near layout and far layout. > I can help review the patch and help test the patches anytime. Do you need help with making a patch to calculate the stripe size for near and far layouts? Let me know how you are going with this patchset, and if there is anything I can do for you. Thanks, Matthew > @Song, do you want me to use a separate patch for this fix, or fix this in > the original patch? > > Merry Christmas > Xiao >
