> On 5/13/21 7:15 AM, Theodore Ts'o wrote: > > On Thu, May 13, 2021 at 06:42:22PM +0900, Changheun Lee wrote: > >> > >> Problem might be casued by exhausting of memory. And memory exhausting > >> would be caused by setting of small bio_max_size. Actually it was not > >> reproduced in my VM environment at first. But, I reproduced same problem > >> when bio_max_size is set with 8KB forced. Too many bio allocation would > >> be occurred by setting of 8KB bio_max_size. > > > > Hmm... I'm not sure how to align your diagnosis with the symptoms in > > the bug report. If we were limited by memory, that should slow down > > the I/O, but we should still be making forward progress, no? And a > > forced reboot should not result in data corruption, unless maybe there > > If you use data=writeback, data writes and journal writes are not > synchronized. So, it may be possible that a journal write made it through, > a data write didn't - the end result would be a file containing random > contents that was on the disk. > > Changheun - do you use data=writeback? Did the corruption happen only in > newly created files? Or did it corrupt existing files? Actually I didn't reproduced data corruption. I only reproduced hang during making ext4 filesystem. Alex, could you check it? > > > was a missing check for a failed memory allocation, causing data to be > > written to the wrong location, a missing error check leading to the > > block or file system layer not noticing that a write had failed > > (although again, memory exhaustion should not lead to failed writes; > > it might slow us down, sure, but if writes are being failed, something > > is Badly Going Wrong --- things like writes to the swap device or > > writes by the page cleaner must succeed, or else Things Would Go Bad > > In A Hurry). > > Mikulas -- dm-devel mailing list dm-devel@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/dm-devel
