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
Please let me know if there's anything else you need. Regards, Klara Modin +CC: linux-nvme
--- lib/iov_iter.c | 67 +++++++++++++++++++++++++++++++++----------------- 1 file changed, 45 insertions(+), 22 deletions(-) diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 1abb32c0da50..9fc06f5fb748 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1677,8 +1677,8 @@ static ssize_t iov_iter_extract_xarray_pages(struct iov_iter *i, }/*- * Extract a list of contiguous pages from an ITER_BVEC iterator. This does - * not get references on the pages, nor does it get a pin on them. + * Extract a list of virtually contiguous pages from an ITER_BVEC iterator. + * This does not get references on the pages, nor does it get a pin on them. */ static ssize_t iov_iter_extract_bvec_pages(struct iov_iter *i, struct page ***pages, size_t maxsize, @@ -1686,35 +1686,58 @@ static ssize_t iov_iter_extract_bvec_pages(struct iov_iter *i, iov_iter_extraction_t extraction_flags, size_t *offset0) { - struct page **p, *page; - size_t skip = i->iov_offset, offset, size; - int k; + size_t skip = i->iov_offset, size = 0; + struct bvec_iter bi; + int k = 0;- for (;;) {- if (i->nr_segs == 0) - return 0; - size = min(maxsize, i->bvec->bv_len - skip); - if (size) - break; + if (i->nr_segs == 0) + return 0; + + if (i->iov_offset == i->bvec->bv_len) { i->iov_offset = 0; i->nr_segs--; i->bvec++; skip = 0; } + bi.bi_size = maxsize + skip; + bi.bi_bvec_done = skip; + + maxpages = want_pages_array(pages, maxsize, skip, maxpages); + + while (bi.bi_size && bi.bi_idx < i->nr_segs) { + struct bio_vec bv = bvec_iter_bvec(i->bvec, bi); + + /* + * The iov_iter_extract_pages interface only allows an offset + * into the first page. Break out of the loop if we see an + * offset into subsequent pages, the caller will have to call + * iov_iter_extract_pages again for the reminder. + */ + if (k) { + if (bv.bv_offset) + break; + } else { + *offset0 = bv.bv_offset; + }- skip += i->bvec->bv_offset;- page = i->bvec->bv_page + skip / PAGE_SIZE; - offset = skip % PAGE_SIZE; - *offset0 = offset; + (*pages)[k++] = bv.bv_page; + size += bv.bv_len;- maxpages = want_pages_array(pages, size, offset, maxpages);- if (!maxpages) - return -ENOMEM; - p = *pages; - for (k = 0; k < maxpages; k++) - p[k] = page + k; + if (k >= maxpages) + break; + + /* + * We are done when the end of the bvec doesn't align to a page + * boundary as that would create a hole in the returned space. + * The caller will handle this with another call to + * iov_iter_extract_pages. + */ + if (bv.bv_offset + bv.bv_len != PAGE_SIZE) + break; + + bvec_iter_advance_single(i->bvec, &bi, bv.bv_len); + }- size = min_t(size_t, size, maxpages * PAGE_SIZE - offset);iov_iter_advance(i, size); return size; }
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# bad: [cadd411a755d40bf717c2514afb90c7c0762aefc] crypto: rsassa-pkcs1 - Migrate to sig_alg backend # good: [e42b1a9a2557aa94fee47f078633677198386a52] Merge tag 'spi-fix-v6.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi git bisect start 'next' 'next/stable' # good: [5837b9daa339313b9009011e0173dd874de3f132] Merge branch 'spi-nor/next' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git git bisect good 5837b9daa339313b9009011e0173dd874de3f132 # bad: [64f1d5c3ad7542ea8f979988d2af75fd4e18148e] Merge branch 'for-backlight-next' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight.git git bisect bad 64f1d5c3ad7542ea8f979988d2af75fd4e18148e # good: [e7103f8785504dd5c6aad118fbc64fc49eda33af] Merge tag 'amd-drm-next-6.13-2024-10-25' of https://gitlab.freedesktop.org/agd5f/linux into drm-next git bisect good e7103f8785504dd5c6aad118fbc64fc49eda33af # good: [7487abf914ecae6ad2690493c2a3fb998738bd71] Merge branch 'for-next' of https://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394.git git bisect good 7487abf914ecae6ad2690493c2a3fb998738bd71 # good: [3f743e703c251c9c3f22088bcdc0330e165c8c94] Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git git bisect good 3f743e703c251c9c3f22088bcdc0330e165c8c94 # bad: [9401ff8e2d60f43ecf343c20a7595b2711bce217] Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux git bisect bad 9401ff8e2d60f43ecf343c20a7595b2711bce217 # good: [aff750e7094e26eae686965930ef2bec7f4152da] io_uring/rsrc: clear ->buf before mapping pages git bisect good aff750e7094e26eae686965930ef2bec7f4152da # good: [904ebd2527c507752f5ddb358f887d2e0dab96a0] block: remove redundant explicit memory barrier from rq_qos waiter and waker git bisect good 904ebd2527c507752f5ddb358f887d2e0dab96a0 # bad: [d49acf07fd5629a7e96d3f6cb4a28f5cc04a10bf] Merge branch 'for-next' of git://git.kernel.dk/linux-block.git git bisect bad d49acf07fd5629a7e96d3f6cb4a28f5cc04a10bf # good: [f1be1788a32e8fa63416ad4518bbd1a85a825c9d] block: model freeze & enter queue as lock for supporting lockdep git bisect good f1be1788a32e8fa63416ad4518bbd1a85a825c9d # bad: [793c08dfe78b646031fe2aa5910e6fef6e872e4a] Merge branch 'for-6.13/block' into for-next git bisect bad 793c08dfe78b646031fe2aa5910e6fef6e872e4a # bad: [2f5a65ef30a636d5030917eebd283ac447a212af] block: add a bdev_limits helper git bisect bad 2f5a65ef30a636d5030917eebd283ac447a212af # bad: [e4e535bff2bc82bb49a633775f9834beeaa527db] iov_iter: don't require contiguous pages in iov_iter_extract_bvec_pages git bisect bad e4e535bff2bc82bb49a633775f9834beeaa527db # first bad commit: [e4e535bff2bc82bb49a633775f9834beeaa527db] iov_iter: don't require contiguous pages in iov_iter_extract_bvec_pages
