The patch titled uml: limit request size on COWed devices has been added to the -mm tree. Its filename is uml-limit-request-size-on-cowed-devices.patch *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find out what to do about this ------------------------------------------------------ Subject: uml: limit request size on COWed devices From: Jeff Dike <jdike@xxxxxxxxxxx> COWed devices can't handle more than 32 (64 on x86_64) sectors in one request due to the size of the bitmap being carried around in the io_thread_req. Enforce that by telling the block layer not to put too many sectors in requests to COWed devices. Signed-off-by: Jeff Dike <jdike@xxxxxxxxxxxxxxx> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@xxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/um/drivers/ubd_kern.c | 2 ++ 1 files changed, 2 insertions(+) diff -puN arch/um/drivers/ubd_kern.c~uml-limit-request-size-on-cowed-devices arch/um/drivers/ubd_kern.c --- a/arch/um/drivers/ubd_kern.c~uml-limit-request-size-on-cowed-devices +++ a/arch/um/drivers/ubd_kern.c @@ -712,6 +712,8 @@ static int ubd_add(int n, char **error_o ubd_dev->queue->queuedata = ubd_dev; blk_queue_max_hw_segments(ubd_dev->queue, MAX_SG); + if(ubd_dev->cow.file != NULL) + blk_queue_max_sectors(ubd_dev->queue, 8 * sizeof(long)); err = ubd_disk_register(MAJOR_NR, ubd_dev->size, n, &ubd_gendisk[n]); if(err){ *error_out = "Failed to register device"; _ Patches currently in -mm which might be from jdike@xxxxxxxxxxx are hostfs-convert-to-new-aops.patch uml-fix-request-sector-update.patch uml-use-get_free_pages-to-allocate-kernel-stacks.patch add-generic-exit-time-stack-depth-checking-to-config_debug_stack_usage.patch uml-xterm-driver-tidying.patch uml-pty-channel-tidying.patch uml-handle-errors-on-opening-host-side-of-consoles.patch uml-sigio-support-cleanup.patch uml-simplify-helper-stack-handling.patch uml-eliminate-kernel-allocator-wrappers.patch uml-export-hostfs-symbols.patch uml-limit-request-size-on-cowed-devices.patch uml-remove-dead-file.patch - To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html