trešd., 2022. g. 2. febr., plkst. 21:13 — lietotājs Matthew Wilcox (<willy@infradead.org>) rakstīja:
On Wed, Feb 02, 2022 at 07:15:14PM +0200, Dāvis Mosāns wrote:
I have a corrupted file on BTRFS which has CoW disabled thus no checksum. Trying to read this file causes the process to get stuck forever. It doesn't return EIO.
How can I find out why it gets stuck?
$ cat /proc/3449/stack | ./scripts/decode_stacktrace.sh vmlinux folio_wait_bit_common (mm/filemap.c:1314) filemap_get_pages (mm/filemap.c:2622) filemap_read (mm/filemap.c:2676) new_sync_read (fs/read_write.c:401 (discriminator 1))
folio_wait_bit_common() is where it waits for the page to be unlocked. Probably the problem is that btrfs isn't unlocking the page on seeing the error, so you don't get the -EIO returned?
Yeah, but how to find where that happens. Anyway by pure luck I found memcpy that wrote outside of allocated memory and fixing that solved this issue but I still don't know how to debug this properly.