Hi Mikulas, > bio_alloc can allocate a bio with at most BIO_MAX_PAGES (256) vector > entries. However, the incoming bio may have more vector entries if it was > allocated by other means. For example, bcache submits bios with more than > BIO_MAX_PAGES entries. This results in bio_alloc failure. > > To avoid the failure, change the code so that it allocates bio with at > most BIO_MAX_PAGES entries. If the incoming bio has more entries, > bio_add_page will fail and a new bio will be allocated - the code that > handles bio_add_page failure already exists in the dm-log-writes target. > > Also, move atomic_inc(&lc->io_blocks) before bio_alloc to fix a bug that > the target hangs if bio_alloc fails. The error path does put_io_block(lc), > so we must do atomic_inc(&lc->io_blocks) before invoking the error path to > avoid underflow of lc->io_blocks. > > Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx # v4.1+ How does this relate to the previous patch you made to dm-crypt? How best should I test this? It looks like the dm-crypt patch fixed the problem. Should I test by applying this patch ONLY and reverting the dm-crypt patch? (i.e. does this patch also fix the problem.) Or should I just test with both patches applied simultaneously? James -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
