On Thu, Oct 31, 2024 at 09:42:32AM +0100, Klara Modin wrote: > On 2024-10-31 01:22, Ming Lei wrote: > > On Thu, Oct 31, 2024 at 08:14:49AM +0800, Ming Lei wrote: > > > On Wed, Oct 30, 2024 at 06:56:48PM +0100, Klara Modin wrote: > > > > Hi, > > > > > > > > On 2024-10-24 07:00, Christoph Hellwig wrote: > > > > > From: Ming Lei <ming.lei@xxxxxxxxxx> > > > > > > > > > > The iov_iter_extract_pages interface allows to return physically > > > > > discontiguous pages, as long as all but the first and last page > > > > > in the array are page aligned and page size. Rewrite > > > > > iov_iter_extract_bvec_pages to take advantage of that instead of only > > > > > returning ranges of physically contiguous pages. > > > > > > > > > > Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx> > > > > > [hch: minor cleanups, new commit log] > > > > > Signed-off-by: Christoph Hellwig <hch@xxxxxx> > > > > > > > > With this patch (e4e535bff2bc82bb49a633775f9834beeaa527db in next-20241030), > > > > I'm unable to connect via nvme-tcp with this in the log: > > > > > > > > nvme nvme1: failed to send request -5 > > > > nvme nvme1: Connect command failed: host path error > > > > nvme nvme1: failed to connect queue: 0 ret=880 > > > > > > > > With the patch reverted it works as expected: > > > > > > > > nvme nvme1: creating 24 I/O queues. > > > > nvme nvme1: mapped 24/0/0 default/read/poll queues. > > > > nvme nvme1: new ctrl: NQN > > > > "nqn.2018-06.eu.kasm.int:freenas:backup:parmesan.int.kasm.eu", addr > > > > [2001:0678:0a5c:1204:6245:cbff:fe9c:4f59]:4420, hostnqn: > > > > nqn.2018-06.eu.kasm.int:parmesan > > > > > > I can't reproduce it by running blktest 'nvme_trtype=tcp ./check nvme/' > > > on both next tree & for-6.13/block. > > > > > > Can you collect the following bpftrace log by running the script before > > > connecting to nvme-tcp? > > I didn't seem to get any output from the bpftrace script (I confirmed that I > had the config as you requested, but I'm not very familiar with bpftrace so > I could have done something wrong). I could, however, reproduce the issue in It works for me on Fedora(37, 40). > qemu and added breakpoints on nvmf_connect_io_queue and > iov_iter_extract_pages. The breakpoint on iov_iter_extract_pages got hit > once when running nvme connect: > > (gdb) break nvmf_connect_io_queue > Breakpoint 1 at 0xffffffff81a5d960: file > /home/klara/git/linux/drivers/nvme/host/fabrics.c, line 525. > (gdb) break iov_iter_extract_pages > Breakpoint 2 at 0xffffffff817633b0: file > /home/klara/git/linux/lib/iov_iter.c, line 1900. > (gdb) c > Continuing. > [Switching to Thread 1.1] Wow, debug kernel with gdb, cool! > > Thread 1 hit Breakpoint 2, iov_iter_extract_pages > (i=i@entry=0xffffc900001ebd68, > pages=pages@entry=0xffffc900001ebb08, maxsize=maxsize@entry=72, > maxpages=8, > extraction_flags=extraction_flags@entry=0, > offset0=offset0@entry=0xffffc900001ebb10) > at /home/klara/git/linux/lib/iov_iter.c:1900 > 1900 { > (gdb) print i->count > $5 = 72 > (gdb) print i->iov_offset > $6 = 0 > (gdb) print i->bvec->bv_offset > $7 = 3952 > (gdb) print i->bvec->bv_len > $8 = 72 > (gdb) c > Continuing. > > I didn't hit the breakpoint in nvmf_connect_io_queue, but I instead hit it > if I add it to nvmf_connect_admin_queue. I added this function to the > bpftrace script but that didn't produce any output either. Your kernel config shows all BTF related options are enabled, maybe bpftrace userspace issue? > > > > > And please try the following patch: > > > > diff --git a/lib/iov_iter.c b/lib/iov_iter.c > > index 9fc06f5fb748..c761f6db3cb4 100644 > > --- a/lib/iov_iter.c > > +++ b/lib/iov_iter.c > > @@ -1699,6 +1699,7 @@ static ssize_t iov_iter_extract_bvec_pages(struct iov_iter *i, > > i->bvec++; > > skip = 0; > > } > > + bi.bi_idx = 0; > > bi.bi_size = maxsize + skip; > > bi.bi_bvec_done = skip; > > > > > > Applying this seems to fix the problem. Thanks for the test, and the patch is sent out. thanks, Ming