Hi,
在 2024/02/27 10:38, Saranya Muruganandam 写道:
Hi,
Is there advice on how to fix this `blockdev --rereadpt` regression in
the kernel?
Would appreciate some advice.
Thanks,
Saranya
On Mon, Feb 12, 2024 at 8:01 PM Saranya Muruganandam
<saranyamohan@xxxxxxxxxx> wrote:
When we fail to read from the disk, BLKRRPART used to be able to
capture and bubble this up to the caller.
It no longer does since we no longer capture the error from bdev_disk_changed.
Here is an example with fault-injection:
# echo 0 > /sys/kernel/debug/fail_make_request/interval
# echo 100 > /sys/kernel/debug/fail_make_request/probability
# echo -1 > /sys/kernel/debug/fail_make_request/times
# echo 1 > /sys/block/sdc/make-it-fail
# blockdev --rereadpt /dev/sdc # no error
# echo $?
0 # incorrectly reports success.
I take a look at this, and it's right the root cause is commit
4601b4b130de ("block: reopen the device in blkdev_reread_part") ignore
errors from bdev_disk_changed() now.
I think we can fix this by returning error from bdev_get_whole() if
bdev_disk_changed() failed, this will cause that open disk to fail now,
however, I think this can be acceptable.
Christoph, do you think so? Or we should distinguish ioctl and open
device and only let ioctl to fail.
Thanks,
Kuai
Whereas fdisk and sfdisk correctly report the issue :
# sfdisk /dev/sdc
sfdisk: cannot open /dev/sdc: Input/output error
# fdisk /dev/sdc
Welcome to fdisk (util-linux 2.28.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
fdisk: cannot open /dev/sdc: Input/output error
Best,
Saranya
On Mon, Feb 12, 2024 at 8:00 PM Saranya Muruganandam
<saranyamohan@xxxxxxxxxx> wrote:
When we fail to read from the disk, BLKRRPART used to be able to capture and bubble this up to the caller.
It no longer does since we no longer capture the error from bdev_disk_changed.
Here is an example with fault-injection:
# echo 0 > /sys/kernel/debug/fail_make_request/interval
# echo 100 > /sys/kernel/debug/fail_make_request/probability
# echo -1 > /sys/kernel/debug/fail_make_request/times
# echo 1 > /sys/block/sdc/make-it-fail
# blockdev --rereadpt /dev/sdc # no error
# echo $?
0 # incorrectly reports success.
Whereas fdisk and sfdisk correctly report the issue :
# sfdisk /dev/sdc
sfdisk: cannot open /dev/sdc: Input/output error
# fdisk /dev/sdc
Welcome to fdisk (util-linux 2.28.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
fdisk: cannot open /dev/sdc: Input/output error
Best,
Saranya
On Mon, Feb 12, 2024 at 7:44 AM Christoph Hellwig <hch@xxxxxx> wrote:
What scenario are you looking at?
.
