forcemerge 56391 56392
close 56391
stop
On 06/07/2022 20:48, Paul Eggert wrote:
On 7/6/22 06:17, Pádraig Brady wrote:
This will usually work, but there are cases where this may lose data,
as previously discussed at:
https://bugzilla.redhat.com/show_bug.cgi?id=921708
http://lists.gnu.org/archive/html/coreutils/2013-03/msg00056.html
I'm not sure cp can robustly clean up in this situation?
Thanks for pointing me to those old discussions. As I understand it, the
worry is that FICLONE will only partly succeed, causing the destination
file to contain some (but not all) the input data, and then if we remove
the output file we'll lose the newly-made partial clone. I don't know
whether FICLONE can do that, but it sounds like a reasonable worry.
If that understanding is correct, then the attached further patch should
suffice, so I boldly installed it.
Yes that's better thanks.
The code looks good, and should cater for any issues
within a single cp instance.
As for overlapping processes accessing a file, this may introduce
new edge cases for where a file will be deleted. But I don't see
a specific issue with that, given there are existing truncation
races etc. with overlapping access to a file. I haven't thought
through all scenarios TBH.
marking this as done.
thanks!
Pádraig
