Miklos, On Thu, Feb 28, 2019 at 02:47:57PM +0300, Kirill Smelkov wrote: > On Thu, Feb 28, 2019 at 09:10:15AM +0100, Miklos Szeredi wrote: > > On Wed, Feb 27, 2019 at 9:39 PM Kirill Smelkov <kirr@xxxxxxxxxx> wrote: > > > > > I more or less agree with this statement. However can we please make the > > > breakage to be explicitly visible with an error instead of exhibiting it > > > via harder to debug stucks/deadlocks? For example sys_read < max_write > > > -> error instead of getting stuck. And if notify_retrieve requests > > > buffer larger than max_write -> error or cut to max_write, but don't > > > return OK when we know we will never send what was requested to > > > filesystem even if it uses max_write sized reads. What is the point of > > > breaking in hard to diagnose way when we can make the breakage showing > > > itself explicitly? Would a patch for such behaviour accepted? > > > > Sure, if it's only adds a couple of lines. Adding more than say ten > > lines for such a non-bug fix is definitely excessive. > > Ok, thanks. Please consider applying the following patch. (It's a bit > pity to hear the problem is not considered to be a bug, but anyway). > > I will also send the second patch as another mail, since I could not > made `git am --scissors` to apply several patched extracted from one > mail successfully. [...] On Thu, Mar 07, 2019 at 12:34:21PM +0300, Kirill Smelkov wrote: > Ping. Miklos, is there anything wrong with this patch and its > second counterpart? As we were talking here are those patches. The first one cuts notify_retrieve request to max_write and is one line only. The second one returns error to filesystem server if it is buggy and does sys_read with buffer size < max_write. It is 2 lines of code and 7 lines of comments. I still think that the patches fix real bugs. It is a bug if server behaviour is a bit non-confirming or simply on an edge of being correct or questionable, and instead of properly getting plain error from kernel, the whole system gets stuck. It is a bug because bug amplification factor here is at least one order of magnitude instead of staying ~1x. I'm sending the patches for the third time already, but did not get any feedback. Could you please have a look? Thanks beforehand, Kirill Kirill Smelkov (2): fuse: retrieve: cap requested size to negotiated max_write fuse: require /dev/fuse reads to have enough buffer capacity as negotiated fs/fuse/dev.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) -- 2.21.0.225.g810b269d1a
