"Yang, Bo" <Bo.Yang@xxxxxxx> writes: > If you are using megasas ioctl routine to develop your owner > application, the best way you may need to contact with LSI for the > tech support. ??? Thanks for answering, but I'm afraid I don't understand. You don't fix bugs in the driver because you don't support the application used to trigger it? The application in question is smartctl which is part of http://smartmontools.sourceforge.net and AFAIK included with most (all?) Linux distributions. The action required to trigger the driver bug is attempting to initiate a SMART device self test. Quoting from the Debian bug report http://bugs.debian.org/604627 : calling 'smartctl -d megaraid,0 /dev/sda -t short' gives: smartctl 5.40 2010-07-12 r3124 [x86_64-unknown-linux-gnu] (local build) Copyright (C) 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net Short offline self test failed [Cannot allocate memory] megasas: Failed to alloc kernel SGL buffer for IOCTL Another user reported the same issue on the linux-ide list: http://marc.info/?l=linux-ide&m=128941801715301 with the following backtrace: [ 69.162393] ------------[ cut here ]------------ [ 69.162404] WARNING: at /build/buildd/linux-2.6.32/mm/page_alloc.c:1806 \ __alloc_pages_slowpath+0x43b/0x580() [ 69.162407] Hardware name: X8DTN [ 69.162409] Modules linked in: fbcon tileblit font bitblit softcursor vga16fb \ vgastate ioatdma radeon ttm drm_kms_helper shpchp drm i2c_algo_bit lp parport floppy \ pata_jmicron megaraid_sas igb dca [ 69.162429] Pid: 1206, comm: smartctl Not \ tainted 2.6.32-25-server #45-Ubuntu [ 69.162432] Call Trace: [ 69.162439] [<ffffffff81065f3b>] warn_slowpath_common+0x7b/0xc0 [ 69.162443] [<ffffffff81065f94>] warn_slowpath_null+0x14/0x20 [ 69.162447] [<ffffffff810f98fb>] __alloc_pages_slowpath+0x43b/0x580 [ 69.162454] [<ffffffff8101078c>] ? __switch_to+0x1ac/0x320 [ 69.162459] [<ffffffff81057850>] ? finish_task_switch+0x50/0xe0 [ 69.162463] [<ffffffff810f9bb1>] __alloc_pages_nodemask+0x171/0x180 [ 69.162468] [<ffffffff81017536>] dma_generic_alloc_coherent+0xa6/0x160 [ 69.162475] [<ffffffff81038b01>] x86_swiotlb_alloc_coherent+0x31/0x70 [ 69.162482] [<ffffffffa002d0ce>] megasas_mgmt_fw_ioctl+0x1ae/0x690 [megaraid_sas] [ 69.162488] [<ffffffffa002d748>] megasas_mgmt_ioctl_fw+0x198/0x240 [megaraid_sas] [ 69.162494] [<ffffffffa002f695>] megasas_mgmt_ioctl+0x35/0x50 [megaraid_sas] [ 69.162500] [<ffffffff81153b12>] vfs_ioctl+0x22/0xa0 [ 69.162505] [<ffffffff8115da2a>] ? alloc_fd+0x10a/0x150 [ 69.162509] [<ffffffff81153cb1>] do_vfs_ioctl+0x81/0x410 [ 69.162515] [<ffffffff8155cc13>] ? do_page_fault+0x153/0x3b0 [ 69.162518] [<ffffffff811540c1>] sys_ioctl+0x81/0xa0 [ 69.162523] [<ffffffff810121b2>] system_call_fastpath+0x16/0x1b [ 69.162526] ---[ end trace 6a2181b634e2abc6 ]--- [ 69.162538] ------------[ cut here ]------------ [ 69.162806] kernel BUG at /build/buildd/linux-2.6.32/lib/swiotlb.c:368! [ 69.163134] invalid opcode: 0000 [#1] SMP [ 69.163570] last sysfs file: \ /sys/devices/system/cpu/cpu3/cache/index2/shared_cpu_map [ 69.163975] CPU 0 [ 69.164227] Modules linked in: fbcon tileblit font bitblit softcursor vga16fb \ vgastate ioatdma radeon ttm drm_kms_helper shpchp drm i2c_algo_bit lp parport floppy \ pata_jmicron megaraid_sas igb dca [ 69.167419] Pid: 1206, comm: smartctl Tainted: G \ W 2.6.32-25-server #45-Ubuntu X8DTN [ 69.167843] RIP: 0010:[<ffffffff812c4dc5>] \ [<ffffffff812c4dc5>] map_single+0x255/0x260 [ 69.168370] RSP: 0018:ffff88081c0ebc58 \ EFLAGS: 00010246 [ 69.168655] RAX: 000000000003bffc RBX: 00000000ffffffff RCX: \ 0000000000000002 [ 69.169000] RDX: 0000000000000000 RSI: 0000000000000000 RDI: \ ffff88001dffe000 [ 69.169346] RBP: ffff88081c0ebcb8 R08: 0000000000000000 R09: \ ffff880000030840 [ 69.169691] R10: 0000000000100000 R11: 0000000000000000 R12: \ 0000000000000000 [ 69.170036] R13: 00000000ffffffff R14: 0000000000000001 R15: \ 0000000000200000 [ 69.170382] FS: 00007fb8de189720(0000) GS:ffff88001de00000(0000) \ knlGS:0000000000000000 [ 69.170794] CS: 0010 DS: 0000 ES: 0000 CR0: \ 0000000080050033 [ 69.171094] CR2: 00007fb8dd59237c CR3: 000000081a790000 CR4: \ 00000000000006f0 [ 69.171439] DR0: 0000000000000000 DR1: 0000000000000000 DR2: \ 0000000000000000 [ 69.171784] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: \ 0000000000000400 [ 69.172130] Process smartctl (pid: 1206, threadinfo \ ffff88081c0ea000, task ffff88081a760000) [ 69.194513] Stack: [ 69.205788] 0000000000000034 00000002817e3390 0000000000000000 ffff88081c0ebe00 [ 69.217739] <0> 0000000000000000 000000000003bffc 0000000000000000 \ 0000000000000000 [ 69.241250] <0> 0000000000000000 00000000ffffffff \ ffff88081c5b4080 ffff88081c0ebe00 [ 69.277310] Call Trace: [ 69.289278] [<ffffffff812c52ac>] swiotlb_alloc_coherent+0xec/0x130 [ 69.301118] [<ffffffff81038b31>] x86_swiotlb_alloc_coherent+0x61/0x70 [ 69.313045] [<ffffffffa002d0ce>] megasas_mgmt_fw_ioctl+0x1ae/0x690 [megaraid_sas] [ 69.336399] [<ffffffffa002d748>] megasas_mgmt_ioctl_fw+0x198/0x240 [megaraid_sas] [ 69.359346] [<ffffffffa002f695>] megasas_mgmt_ioctl+0x35/0x50 [megaraid_sas] [ 69.370902] [<ffffffff81153b12>] vfs_ioctl+0x22/0xa0 [ 69.382322] [<ffffffff8115da2a>] ? alloc_fd+0x10a/0x150 [ 69.393622] [<ffffffff81153cb1>] do_vfs_ioctl+0x81/0x410 [ 69.404696] [<ffffffff8155cc13>] ? do_page_fault+0x153/0x3b0 [ 69.415761] [<ffffffff811540c1>] sys_ioctl+0x81/0xa0 [ 69.426640] [<ffffffff810121b2>] system_call_fastpath+0x16/0x1b [ 69.437491] Code: fe ff ff 48 8b 3d 74 38 76 00 41 bf 00 00 20 00 e8 51 f5 d7 ff \ 83 e0 ff 48 05 ff 07 00 00 48 c1 e8 0b 48 89 45 c8 e9 13 fe ff ff <0f> 0b eb fe 0f 1f \ 80 00 00 00 00 55 48 89 e5 48 83 ec 20 4c 89 [ 69.478216] RIP [<ffffffff812c4dc5>] \ map_single+0x255/0x260 [ 69.489668] RSP <ffff88081c0ebc58> [ 69.500975] ---[ end trace 6a2181b634e2abc7 ]--- Both users have confirmed that the patch fixes their problem. One could of course imagine a workaround in the smartctl application so that it never sent requests with a zero iov_len, but I still believe that actually fixing the driver to handle such requests is better. No? BjÃrn -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
