Hi Samuel, On 10/11/20 6:21 pm, Samuel Thibault wrote: >> It seems to be compiled with -D_FILE_OFFSET_BITS=64 already by default: > > But is rumpkernel itself also built with it? > > Really, better actually *test* that offsets are getting properly > propagated.
Test program output: ``` ... wd0: <QEMU HARDDISK> wd0: drive supports 16-sector PIO transfers, LBA48 addressing wd0: 298 GB, 620181 cyl, 16 head, 63 sec, 512 bytes/sect x 625142448 sectors irq handler [10]: release a dead delivery port ee61c668 entry f5cef8e0 irq handler [10]: removed entry f5cef8e0 wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 5 (Ultra/100) wd0(ahcisata0:0:0): using PIO mode 4, DMA mode 2, Ultra-DMA mode 5 (Ultra/100) ( using DMA) Offset = 0xcbba00000 found /dev/wd0d d m u ya G _ G _ S G _ 8 a MB 62 G /mnt3dia/damien/1c0c6182- rump kernel halting...f19aa 22 M2 t ) U 9 \ qM syncing disks... done unmounting file systems... unmounted rumpfs on / type rumpfs unmounting done ``` I compiled a test program that opens the block device and reads a page from the beginning of /dev/wd0s3 using rump libs and dumps it as ASCII above. I tested in linux on the same disk with dd to dump the same page and it matches what hurd found with rump libs. If I truncate the offset to 32 bits, ie 0xbba00000, it has different content. Therefore, the 64 bit offsets seem to be propagating. I also printed inside rumpdisk to dump the offsets before calling pread/pwrite, these offsets are sometimes wider than 32 bits, sometimes not. Damien
