[snip]
>I don't think the later was_short can handle the hole case. For the hole case,
>we should try reading next strip object instead of return. how about
>below patch.
>
Hi Yan,
i uesed this demo to test hole case.
dd if=/dev/urandom bs=4096 count=2 of=file_with_holes
dd if=/dev/urandom bs=4096 seek=7 count=2 of=file_with_holes
dd if=file_with_holes of=/dev/null bs=16k count=1 iflag=direct
Using the dynamic_debug in striped_read, the message are:
>[ 8743.663499] ceph: file.c:350 : striped_read 0~16384 (read 0) got 16384
>[ 8743.663502] ceph: file.c:390 : striped_read returns 16384
>From the messages, we can see it can't hit the short-read.
For the ceph-file-hole, how does the ceph handle?
Or am i missing something?
Thanks!
Jianpeng Ma
>Regards
>Yan, Zheng
>---
>diff --git a/fs/ceph/file.c b/fs/ceph/file.c
>index 271a346..6ca2921 100644
>--- a/fs/ceph/file.c
>+++ b/fs/ceph/file.c
>@@ -350,16 +350,17 @@ more:
> ret, hit_stripe ? " HITSTRIPE" : "", was_short ? " SHORT" : "");
>
> if (ret > 0) {
>- int didpages = (page_align + ret) >> PAGE_CACHE_SHIFT;
>+ int didpages = (page_align + this_len) >> PAGE_CACHE_SHIFT;
>
>- if (read < pos - off) {
>- dout(" zero gap %llu to %llu\n", off + read, pos);
>- ceph_zero_page_vector_range(page_align + read,
>- pos - off - read, pages);
>+ if (was_short) {
>+ dout(" zero gap %llu to %llu\n",
>+ pos + ret, pos + this_len);
>+ ceph_zero_page_vector_range(page_align + ret,
>+ this_len - ret, page_pos);
> }
>- pos += ret;
>+ pos += this_len;
> read = pos - off;
>- left -= ret;
>+ left -= this_len;
> page_pos += didpages;
> pages_left -= didpages;
>
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