On Tuesday October 31, akpm@xxxxxxxx wrote: > On Tue, 31 Oct 2006 17:00:51 +1100 > NeilBrown <neilb@xxxxxxx> wrote: > > > Currently md devices are created when first opened and remain in existence > > until the module is unloaded. > > This isn't a major problem, but it somewhat ugly. > > > > This patch changes the lifetime rules so that an md device will > > disappear on the last close if it has no state. > > This kills the G5: > > > EXT3-fs: recovery complete. > EXT3-fs: mounted filesystem with ordered data mode. > Oops: Kernel access of bad area, sig: 11 [#1] > SMP NR_CPUS=4 > Modules linked in: > NIP: C0000000001A31B8 LR: C00000000018E5DC CTR: C0000000001A3404 > REGS: c0000000017ff4a0 TRAP: 0300 Not tainted (2.6.19-rc4-mm1) > MSR: 9000000000009032 <EE,ME,IR,DR> CR: 84000048 XER: 00000000 > DAR: 6B6B6B6B6B6B6BB3, DSISR: 0000000040000000 > TASK = c00000000ff2b7f0[1899] 'nash' THREAD: c0000000017fc000 CPU: 1 > GPR00: 0000000000000008 C0000000017FF720 C0000000006B26D0 6B6B6B6B6B6B6B7B .. > NIP [C0000000001A31B8] .kobject_uevent+0xac/0x55c > LR [C00000000018E5DC] .__elv_unregister_queue+0x20/0x44 > Call Trace: > [C0000000017FF720] [C000000000562508] read_pipe_fops+0xd0/0xd8 (unreliable) > [C0000000017FF840] [C00000000018E5DC] .__elv_unregister_queue+0x20/0x44 > [C0000000017FF8D0] [C000000000195548] .blk_unregister_queue+0x58/0x9c > [C0000000017FF960] [C00000000019683C] .unlink_gendisk+0x1c/0x50 > [C0000000017FF9F0] [C000000000122840] .del_gendisk+0x98/0x22c I'm guessing we need diff .prev/block/elevator.c ./block/elevator.c --- .prev/block/elevator.c 2006-10-31 20:06:22.000000000 +1100 +++ ./block/elevator.c 2006-10-31 20:06:40.000000000 +1100 @@ -926,7 +926,7 @@ static void __elv_unregister_queue(eleva void elv_unregister_queue(struct request_queue *q) { - if (q) + if (q && q->elevator) __elv_unregister_queue(q->elevator); } Jens? md never registers and elevator for its queue. > > Also, it'd be nice to enable CONFIG_MUST_CHECK and take a look at a few > things... > > drivers/md/md.c: In function `bind_rdev_to_array': > drivers/md/md.c:1379: warning: ignoring return value of `kobject_add', declared with attribute warn_unused_result > drivers/md/md.c:1385: warning: ignoring return value of `sysfs_create_link', declared with attribute warn_unused_result > drivers/md/md.c: In function `md_probe': > drivers/md/md.c:2986: warning: ignoring return value of `kobject_register', declared with attribute warn_unused_result > drivers/md/md.c: In function `do_md_run': > drivers/md/md.c:3135: warning: ignoring return value of `sysfs_create_group', declared with attribute warn_unused_result > drivers/md/md.c:3150: warning: ignoring return value of `sysfs_create_link', declared with attribute warn_unused_result > drivers/md/md.c: In function `md_check_recovery': > drivers/md/md.c:5446: warning: ignoring return value of `sysfs_create_link', declared with attribute warn_unused_result I guess... I saw mail a while ago about why we really should be checking those. I'll have to dig it up again. NeilBrown - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html