Messages in this thread | | | From | Peter Kalauskas <> | Date | Tue, 21 Aug 2018 18:28:51 -0700 | Subject | Re: [PATCH] zram: fix bug storing backing_dev |
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On Tue, Aug 14, 2018 at 04:45:23PM -0700, Andrew Morton wrote: > The changelog doesn't describe the end-user impact of the bug, which is > very desirable when tagging a patch for -stable backporting. Can we > have that paragraph please?
The end-user impact is that echoing to writeback_dev would not cause it to change. Would the following statement suffice?
Without this change, it is not possible to change writeback_dev unless the tool used to do so does not include a newline character. For example, 'echo -n' or 'printf' would work, but 'echo' would not work.
I can also include Sergey's description of the bug if that would be helpful.
On Thu, Aug 16, 2018 at 10:48:35AM +0900, Sergey Senozhatsky wrote: > On (08/14/18 16:45), Andrew Morton wrote: > > > > > > > > - strlcpy(file_name, buf, len); > > > > > > This is quite interesting. The reason it worked before was the fact that > > > strlcpy() copies 'len - 1' bytes, which is strlen(buf) - 1 in our case, > > > so it accidentally didn't copy the trailing new line symbol. Which also > > > means that "echo -n /dev/sdX" most likely was broken. > > > > > > > I can't find the original email on lkml for some reason, but I > > recreated the patch. > > Neither can I. >
Sorry, I sent it to Minchan directly. I'll send PATCH v2 to lkml, if v2 is needed.
On Wed, Aug 15, 2018 at 08:32:26PM -0700, Andrew Morton wrote: > On Thu, 16 Aug 2018 10:48:35 +0900 Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> wrote: > > > > The implementation might be able to use strim() somehow. > > > > strim() trims white-spaces. > > Which includes \n. >
The if statement is already used by comp_algorithm_store in zram_drv.c, so perhaps it should remain the if statement for consistency. What do you think, should I use strim or the if statement?
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