Messages in this thread | | | Date | Mon, 12 Jan 2004 01:52:38 +0000 | From | viro@parcelfa ... | Subject | Re: 2.6.0: blkdev_get() oopses on floppy |
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On Sun, Jan 11, 2004 at 11:50:32PM +0100, Xavier Bestel wrote: > Hi guys, > > I writing a piece of code which piggybacks on a block_device (a bit like > dm/md). This particular piece of test code: > err = blkdev_get(bdev, FMODE_READ, 0, BDEV_RAW); > if(err) > { > printk(KERN_ERR "blkdev_get: error %d\n", -err); > goto no_get; > } > printk(KERN_INFO "using device %s\n", dev->bd_disk->disk_name); > blkdev_put(bdev, BDEV_RAW); > no_get: > bdput(bdev);
That's wrong - faling blkdev_get() will do bdput() itself.
*NOTE*: unless you are really forced to, don't use that "open by device number" crap at all - normal filp_open() will do nicely if you have the pathname of device in question and it's _much_ better interface.
> raw /dev/raw/raw1 /dev/fd0 > cat /dev/raw/raw1 >/dev/null > > and got this oops: > > Unable to handle kernel NULL pointer dereference at virtual address 00000040 > printing eip: > d08a285a > *pde = 00000000 > Oops: 0000 [#4] > CPU: 0 > EIP: 0060:[<d08a285a>] Not tainted > EFLAGS: 00000296 > EIP is at floppy_open+0x1a/0x410 [floppy] > eax: 00000000 ebx: d08a2840 ecx: d08a9044 edx: d08a9584 > esi: cfc9aac0 edi: cba1be6c ebp: cfff108c esp: cba1bd5c > ds: 007b es: 007b ss: 0068 > Process cat (pid: 16749, threadinfo=cba1a000 task=cc29f3a0) > Stack: c01fb800 00000000 cba1a000 00000001 cfff1040 cc2d9540 d08a2840 cfc9aac0 > cfff1040 d08a99c0 c015e964 cfff108c cba1be6c cffff8c8 c11d9b60 cba1a000 > 00000246 cfff104c c0395420 00000000 cfff1040 00000001 cba1be6c cc2d9540 > Call Trace: > [<c01fb800>] exact_match+0x0/0x10 > [<d08a2840>] floppy_open+0x0/0x410 [floppy] > [<c015e964>] do_open+0x134/0x410 > [<c015ecbe>] blkdev_get+0x7e/0xa0 > [<d08c9087>] raw_open+0x87/0x150 [raw] > [<c015f932>] chrdev_open+0xf2/0x220 > [<c0165516>] open_namei+0xa6/0x400 > [<c0155630>] dentry_open+0x150/0x210 > [<c01554d8>] filp_open+0x68/0x70 > [<c015597b>] sys_open+0x5b/0x90 > [<c010b3d9>] sysenter_past_esp+0x52/0x71 > > Code: 8b 40 40 8b 70 28 b8 f0 ff ff ff 89 44 24 10 c7 47 74 00 00
Lovely... Which kernel is that? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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