gnats/219: large PRs or updates take many minutes to process

gnats/219: large PRs or updates take many minutes to process

[dirk]

>Number:         219
>Category:       gnats
>Synopsis:       large PRs or updates take many minutes to process
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Jul 13 21:24:00 PDT 2001
>Closed-Date:
>Last-Modified:
>Originator:     dirk bergstrom, juniper networks, inc.
>Release:        gnats 4.0a
>Organization:
>Environment:
FreeBSD aphid.juniper.net 4.2-STABLE FreeBSD 4.2-STABLE
>Description:
if you try to submit a large (>500K) update to an existing PR vai email,
pr-edit goes nuts, eating 98% of CPU for many minutes (well over an hour
for my 1.4 MB testcase).  the entire gnats database
is locked while this goes on (and on).  it's an effective DOS
attack...

dbergstr@crawler:gnats/db/gnats-queue:166> ls -l bigstuff
-rw-rw-r--  1 dbergstr  foo  1440602 Jul 13 16:14 bigstuff
dbergstr@crawler:gnats/db/gnats-queue:167> ps auwwx | grep gnats
gnats    28675 98.1  0.5  1520 1192  p0  R     4:14PM   85:40.87 /opt/gnats/libexec/gnats/pr-edit --database=default -f bigstuff --submit
gnats    28667  0.0  0.3  1048  644  p0  I     4:14PM   0:00.14 /opt/gnats/libexec/gnats/queue-pr --run -d default
gnats    28668  0.0  0.1   632  272  p0  I     4:14PM   0:00.01 /bin/sh /opt/gnats/libexec/gnats/file-pr -f bigstuff --database default
>How-To-Repeat:
create a PR, then submit a very large update to that PR via email.
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: