* [Bug debuginfod/29474] Server returns 404 for concurrent requests when leading to a same .rpm
2022-08-11 16:48 [Bug debuginfod/29474] New: Server returns 404 for concurrent requests when leading to a same .rpm mliska at suse dot cz
@ 2022-08-11 20:17 ` mliska at suse dot cz
2022-08-11 20:30 ` mliska at suse dot cz
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: mliska at suse dot cz @ 2022-08-11 20:17 UTC (permalink / raw)
To: elfutils-devel
https://sourceware.org/bugzilla/show_bug.cgi?id=29474
--- Comment #1 from Martin Liska <mliska at suse dot cz> ---
Have a better knowledge of what happens. Let's assume the following debugging
patch:
diff --git a/debuginfod/debuginfod.cxx b/debuginfod/debuginfod.cxx
index a089d0bd..0320f289 100644
--- a/debuginfod/debuginfod.cxx
+++ b/debuginfod/debuginfod.cxx
@@ -1743,7 +1743,10 @@ handle_buildid_r_match (bool internal_req_p,
continue;
if (fdcache.probe (b_source0, fn)) // skip if already interned
+ {
+ obatched(clog) << "SKIPPING due to probe=" << b_source1 << "
filename=" << fn << " r=" << r << endl;
continue;
+ }
// extract this file to a temporary file
char* tmppath = NULL;
@@ -1776,6 +1779,7 @@ handle_buildid_r_match (bool internal_req_p,
{
// NB: now we know we have a complete reusable file; make fdcache
// responsible for unlinking it later.
+ obatched(clog) << "INTERN " << b_source1 << " filename=" << fn <<
endl;
fdcache.intern(b_source0, fn,
tmppath, archive_entry_size(e),
false); // prefetched ones go to the prefetch cache
@@ -1792,6 +1796,7 @@ handle_buildid_r_match (bool internal_req_p,
inc_metric ("http_responses_total","result",archive_extension + "
archive");
r = MHD_create_response_from_fd (archive_entry_size(e), fd);
+ obatched(clog) << "ASSIGN " << b_source1 << " filename=" << fn << " r="
<< r << endl;
if (r == 0)
{
if (verbose)
@@ -1820,6 +1825,7 @@ handle_buildid_r_match (bool internal_req_p,
}
// XXX: rpm/file not found: delete this R entry?
+ obatched(clog) << "RETURN" << b_source1 << " r=" << r << endl;
return r;
}
debuginfod log shows:
...
[Thu 11 Aug 2022 08:02:42 PM GMT] (21225/21257): found mtime=1659137364 stype=R
source0=/home/marxin/BIG/test/cross-aarch64-gcc12-debuginfo-12.1.1+git287-1.1.x86_64.rpm
source1=/usr/lib/debug/.dwz/cross-aarch64-gcc12-12.1.1+git287-1.1.x86_64
[Thu 11 Aug 2022 08:02:42 PM GMT] (21225/21251): found mtime=1659137364 stype=R
source0=/home/marxin/BIG/test/cross-aarch64-gcc12-debuginfo-12.1.1+git287-1.1.x86_64.rpm
source1=/usr/lib/debug/usr/aarch64-suse-linux/sys-root/lib64/libgcc_s.so.1-12.1.1+git287-1.1.x86_64.debug
...
[Thu 11 Aug 2022 08:02:42 PM GMT] (21225/21257): INTERN
/usr/lib/debug/.dwz/cross-aarch64-gcc12-12.1.1+git287-1.1.x86_64
filename=/usr/lib/debug/usr/aarch64-suse-linux/sys-root/lib64/libgcc_s.so.1-12.1.1+git287-1.1.x86_64.debug
<- so here 21257 request interns libgcc_s.so.1-12.1.1+git287-1.1.x86_64.debug
[Thu 11 Aug 2022 08:02:42 PM GMT] (21225/21251): SKIPPING due to
probe=/usr/lib/debug/usr/aarch64-suse-linux/sys-root/lib64/libgcc_s.so.1-12.1.1+git287-1.1.x86_64.debug
filename=/usr/lib/debug/usr/aarch64-suse-linux/sys-root/lib64/libgcc_s.so.1-12.1.1+git287-1.1.x86_64.debug
r=0 <- and due to that it's skipped here and we never assign r = ...
[Thu 11 Aug 2022 08:02:43 PM GMT] (21225/21251):
RETURN/usr/lib/debug/usr/aarch64-suse-linux/sys-root/lib64/libgcc_s.so.1-12.1.1+git287-1.1.x86_64.debug
r=0
...
Note in correct run the following happens:
[Thu 11 Aug 2022 08:16:42 PM GMT] (22289/22319): ASSIGN
/usr/lib/debug/usr/aarch64-suse-linux/sys-root/lib64/libgcc_s.so.1-12.1.1+git287-1.1.x86_64.debug
filename=/usr/lib/debug/usr/aarch64-suse-linux/sys-root/lib64/libgcc_s.so.1-12.1.1+git287-1.1.x86_64.debug
r=0x7fff740548c0
...
[Thu 11 Aug 2022 08:16:43 PM GMT] (22289/22319):
RETURN/usr/lib/debug/usr/aarch64-suse-linux/sys-root/lib64/libgcc_s.so.1-12.1.1+git287-1.1.x86_64.debug
r=0x7fff740548c0
So the problem is somehow related to fdcache.
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^ permalink raw reply [flat|nested] 7+ messages in thread* [Bug debuginfod/29474] Server returns 404 for concurrent requests when leading to a same .rpm
2022-08-11 16:48 [Bug debuginfod/29474] New: Server returns 404 for concurrent requests when leading to a same .rpm mliska at suse dot cz
2022-08-11 20:17 ` [Bug debuginfod/29474] " mliska at suse dot cz
@ 2022-08-11 20:30 ` mliska at suse dot cz
2022-08-11 20:39 ` mliska at suse dot cz
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: mliska at suse dot cz @ 2022-08-11 20:30 UTC (permalink / raw)
To: elfutils-devel
https://sourceware.org/bugzilla/show_bug.cgi?id=29474
--- Comment #2 from Martin Liska <mliska at suse dot cz> ---
So it's the prefetching feature as documented here:
// 3) extract some number of prefetched entries (just into fdcache)
...
if (r != 0) // stage 3
{
// NB: now we know we have a complete reusable file; make fdcache
// responsible for unlinking it later.
obatched(clog) << "INTERN " << b_source1 << " filename=" << fn <<
endl;
fdcache.intern(b_source0, fn,
tmppath, archive_entry_size(e),
false); // prefetched ones go to the prefetch cache
prefetch_count --;
close (fd); // we're not saving this fd to make a mhd-response from!
continue;
}
So what's bad is that
handle_buildid_r_match begins with:
// check for a match in the fdcache first
int fd = fdcache.lookup(b_source0, b_source1);
while (fd >= 0) // got one!; NB: this is really an if() with a possible
branch out to the end
{
...
}
which was false, but happens to be true once another thread inters the file :/
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^ permalink raw reply [flat|nested] 7+ messages in thread* [Bug debuginfod/29474] Server returns 404 for concurrent requests when leading to a same .rpm
2022-08-11 16:48 [Bug debuginfod/29474] New: Server returns 404 for concurrent requests when leading to a same .rpm mliska at suse dot cz
2022-08-11 20:17 ` [Bug debuginfod/29474] " mliska at suse dot cz
2022-08-11 20:30 ` mliska at suse dot cz
@ 2022-08-11 20:39 ` mliska at suse dot cz
2022-08-11 20:42 ` mliska at suse dot cz
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: mliska at suse dot cz @ 2022-08-11 20:39 UTC (permalink / raw)
To: elfutils-devel
https://sourceware.org/bugzilla/show_bug.cgi?id=29474
--- Comment #3 from Martin Liska <mliska at suse dot cz> ---
Created attachment 14271
--> https://sourceware.org/bugzilla/attachment.cgi?id=14271&action=edit
Possible patch candidate (needs removal of extra debugging)
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^ permalink raw reply [flat|nested] 7+ messages in thread* [Bug debuginfod/29474] Server returns 404 for concurrent requests when leading to a same .rpm
2022-08-11 16:48 [Bug debuginfod/29474] New: Server returns 404 for concurrent requests when leading to a same .rpm mliska at suse dot cz
` (2 preceding siblings ...)
2022-08-11 20:39 ` mliska at suse dot cz
@ 2022-08-11 20:42 ` mliska at suse dot cz
2022-08-15 7:55 ` mliska at suse dot cz
2022-08-15 10:27 ` fche at redhat dot com
5 siblings, 0 replies; 7+ messages in thread
From: mliska at suse dot cz @ 2022-08-11 20:42 UTC (permalink / raw)
To: elfutils-devel
https://sourceware.org/bugzilla/show_bug.cgi?id=29474
Martin Liska <mliska at suse dot cz> changed:
What |Removed |Added
----------------------------------------------------------------------------
Attachment #14271|0 |1
is obsolete| |
--- Comment #4 from Martin Liska <mliska at suse dot cz> ---
Created attachment 14272
--> https://sourceware.org/bugzilla/attachment.cgi?id=14272&action=edit
Possible patch candidate (needs removal of extra debugging) v2
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^ permalink raw reply [flat|nested] 7+ messages in thread* [Bug debuginfod/29474] Server returns 404 for concurrent requests when leading to a same .rpm
2022-08-11 16:48 [Bug debuginfod/29474] New: Server returns 404 for concurrent requests when leading to a same .rpm mliska at suse dot cz
` (3 preceding siblings ...)
2022-08-11 20:42 ` mliska at suse dot cz
@ 2022-08-15 7:55 ` mliska at suse dot cz
2022-08-15 10:27 ` fche at redhat dot com
5 siblings, 0 replies; 7+ messages in thread
From: mliska at suse dot cz @ 2022-08-15 7:55 UTC (permalink / raw)
To: elfutils-devel
https://sourceware.org/bugzilla/show_bug.cgi?id=29474
Martin Liska <mliska at suse dot cz> changed:
What |Removed |Added
----------------------------------------------------------------------------
Assignee|unassigned at sourceware dot org |mliska at suse dot cz
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^ permalink raw reply [flat|nested] 7+ messages in thread* [Bug debuginfod/29474] Server returns 404 for concurrent requests when leading to a same .rpm
2022-08-11 16:48 [Bug debuginfod/29474] New: Server returns 404 for concurrent requests when leading to a same .rpm mliska at suse dot cz
` (4 preceding siblings ...)
2022-08-15 7:55 ` mliska at suse dot cz
@ 2022-08-15 10:27 ` fche at redhat dot com
5 siblings, 0 replies; 7+ messages in thread
From: fche at redhat dot com @ 2022-08-15 10:27 UTC (permalink / raw)
To: elfutils-devel
https://sourceware.org/bugzilla/show_bug.cgi?id=29474
Frank Ch. Eigler <fche at redhat dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution|--- |FIXED
--- Comment #5 from Frank Ch. Eigler <fche at redhat dot com> ---
elfutils-0.187-44-g31d6b1fe7 / debuginfod/ChangeLog debuginfod/debuginfod.cxx:
PR29474: debuginfod
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