xfstest generic/095 triggers soft lockups in kcephfs. It uses fio to
drive some I/O via vmsplice ane splice. Ceph then ends up trying to
access an ITER_BVEC type iov_iter as a ITER_IOVEC one. That causes it to
pick up a wrong offset and get stuck in an infinite loop while trying to
populate the page array. dio_get_pagev_size has a similar problem.
Now that iov_iter_get_pages_alloc doesn't stop after the first vector in
the array, we can just call it instead and dump the old code that tried
to do the same thing.
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/ceph/file.c | 75 +++-------------------------------------------------------
1 file changed, 3 insertions(+), 72 deletions(-)
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 045d30d26624..0ce79f1eabbc 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -35,75 +35,6 @@
*/
/*
- * Calculate the length sum of direct io vectors that can
- * be combined into one page vector.
- */
-static size_t dio_get_pagev_size(const struct iov_iter *it)
-{
- const struct iovec *iov = it->iov;
- const struct iovec *iovend = iov + it->nr_segs;
- size_t size;
-
- size = iov->iov_len - it->iov_offset;
- /*
- * An iov can be page vectored when both the current tail
- * and the next base are page aligned.
- */
- while (PAGE_ALIGNED((iov->iov_base + iov->iov_len)) &&
- (++iov < iovend && PAGE_ALIGNED((iov->iov_base)))) {
- size += iov->iov_len;
- }
- dout("dio_get_pagevlen len = %zu\n", size);
- return size;
-}
-
-/*
- * Allocate a page vector based on (@it, @nbytes).
- * The return value is the tuple describing a page vector,
- * that is (@pages, @page_align, @num_pages).
- */
-static struct page **
-dio_get_pages_alloc(const struct iov_iter *it, size_t nbytes,
- size_t *page_align, int *num_pages)
-{
- struct iov_iter tmp_it = *it;
- size_t align;
- struct page **pages;
- int ret = 0, idx, npages;
-
- align = (unsigned long)(it->iov->iov_base + it->iov_offset) &
- (PAGE_SIZE - 1);
- npages = calc_pages_for(align, nbytes);
- pages = kmalloc(sizeof(*pages) * npages, GFP_KERNEL);
- if (!pages) {
- pages = vmalloc(sizeof(*pages) * npages);
- if (!pages)
- return ERR_PTR(-ENOMEM);
- }
-
- for (idx = 0; idx < npages; ) {
- size_t start;
- ret = iov_iter_get_pages(&tmp_it, pages + idx, nbytes,
- npages - idx, &start);
- if (ret < 0)
- goto fail;
-
- iov_iter_advance(&tmp_it, ret);
- nbytes -= ret;
- idx += (ret + start + PAGE_SIZE - 1) / PAGE_SIZE;
- }
-
- BUG_ON(nbytes != 0);
- *num_pages = npages;
- *page_align = align;
- dout("dio_get_pages_alloc: got %d pages align %zu\n", npages, align);
- return pages;
-fail:
- ceph_put_page_vector(pages, idx, false);
- return ERR_PTR(ret);
-}
-
-/*
* Prepare an open request. Preallocate ceph_cap to avoid an
* inopportune ENOMEM later.
*/
@@ -923,7 +854,7 @@ ceph_direct_read_write(struct kiocb *iocb, struct iov_iter *iter,
}
while (iov_iter_count(iter) > 0) {
- u64 size = dio_get_pagev_size(iter);
+ u64 size = iov_iter_count(iter);
size_t start = 0;
ssize_t len;
@@ -943,13 +874,13 @@ ceph_direct_read_write(struct kiocb *iocb, struct iov_iter *iter,
break;
}
- len = size;
- pages = dio_get_pages_alloc(iter, len, &start, &num_pages);
+ len = iov_iter_get_pages_alloc(iter, &pages, size, &start);
if (IS_ERR(pages)) {
ceph_osdc_put_request(req);
ret = PTR_ERR(pages);
break;
}
+ num_pages = DIV_ROUND_UP(len, PAGE_SIZE);
/*
* To simplify error handling, allow AIO when IO within i_size
--
2.9.3
--
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