Re: [PATCH] Fix a bdi reregistration race, v2

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 11/24/2015 03:13 PM, Christoph Hellwig wrote:
What sort of re-registration is this? Seems like we should only
release the minor number once the bdi is released.

Hello Christoph,

As you most likely know the BDI device name for disks is based on the device major and minor number:

$ ls -l /dev/sda
brw-rw---- 1 root disk 8, 0 Nov 24 14:53 /dev/sda
$ ls -l /sys/block/sda/bdi
lrwxrwxrwx 1 root root 0 Nov 24 15:17 /sys/block/sda/bdi -> ../../../../../../../../virtual/bdi/8:0

So if a driver stops using a (major, minor) number pair and the same device number is reused before the bdi device has been released the warning mentioned in the patch description at the start of this thread is triggered. This patch fixes that race by removing the bdi device from sysfs during the __scsi_remove_device() call instead of when the bdi device is released.

Bart.

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>



[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux]     [Linux OMAP]     [Linux MIPS]     [ECOS]     [Asterisk Internet PBX]     [Linux API]