Hi all Now mkfs on raid10 which is combined with ssd/nvme disks takes a long time. This patch set tries to resolve this problem. This patch set had been reverted because of a data corruption problem. This version fix this problem. The root cause which causes the data corruption is the wrong calculation of start address of near copies disks. 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. [ 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. This version simply spilt the un-aligned part with strip size. And it fixes another problem. The calculation of stripe_size is wrong in reverted version. Xiao Ni (5): md: add md_submit_discard_bio() for submitting discard bio md/raid10: extend r10bio devs to raid disks md/raid10: pull codes that wait for blocked dev into one function md/raid10: improve raid10 discard request md/raid10: improve discard request for far layout drivers/md/md.c | 20 +++ drivers/md/md.h | 2 + drivers/md/raid0.c | 14 +- drivers/md/raid10.c | 429 +++++++++++++++++++++++++++++++++++++++++++++------- drivers/md/raid10.h | 1 + 5 files changed, 397 insertions(+), 69 deletions(-) -- 2.7.5
