From d0985394e7fee6b25a7cc8335d45bc1c1a8ab2d3 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 10 Nov 2011 09:03:55 +0100 Subject: block: Revert "[SCSI] genhd: add a new attribute "alias" in gendisk" This reverts commit a72c5e5eb738033938ab30d6a634b74d1d060f10. The commit introduced alias for block devices which is intended to be used during logging although actual usage hasn't been committed yet. This approach adds very limited benefit (raw log might be easier to follow) which can be trivially implemented in userland but has a lot of problems. It is much worse than netif renames because it doesn't rename the actual device but just adds conveninence name which isn't used universally or enforced. Everything internal including device lookup and sysfs still uses the internal name and nothing prevents two devices from using conflicting alias - ie. sda can have sdb as its alias. This has been nacked by people working on device driver core, block layer and kernel-userland interface and shouldn't have been upstreamed. Revert it. http://thread.gmane.org/gmane.linux.kernel/1155104 http://thread.gmane.org/gmane.linux.scsi/68632 http://thread.gmane.org/gmane.linux.scsi/69776 Signed-off-by: Tejun Heo Acked-by: Greg Kroah-Hartman Acked-by: Kay Sievers Cc: "James E.J. Bottomley" Cc: Nao Nishijima Cc: Alan Cox Cc: Al Viro Signed-off-by: Jens Axboe --- Documentation/ABI/testing/sysfs-block | 13 ------------- 1 file changed, 13 deletions(-) (limited to 'Documentation') diff --git a/Documentation/ABI/testing/sysfs-block b/Documentation/ABI/testing/sysfs-block index 2b5d561..c1eb41c 100644 --- a/Documentation/ABI/testing/sysfs-block +++ b/Documentation/ABI/testing/sysfs-block @@ -206,16 +206,3 @@ Description: when a discarded area is read the discard_zeroes_data parameter will be set to one. Otherwise it will be 0 and the result of reading a discarded area is undefined. -What: /sys/block//alias -Date: Aug 2011 -Contact: Nao Nishijima -Description: - A raw device name of a disk does not always point a same disk - each boot-up time. Therefore, users have to use persistent - device names, which udev creates when the kernel finds a disk, - instead of raw device name. However, kernel doesn't show those - persistent names on its messages (e.g. dmesg). - This file can store an alias of the disk and it would be - appeared in kernel messages if it is set. A disk can have an - alias which length is up to 255bytes. Users can use alphabets, - numbers, "-" and "_" in alias name. This file is writeonce. -- cgit v1.1 From 0007a4c90a11a5371c8b3f80b220fa402a399189 Mon Sep 17 00:00:00 2001 From: "Stephen M. Cameron" Date: Wed, 16 Nov 2011 09:21:49 +0100 Subject: cciss: auto engage SCSI mid layer at driver load time A long time ago, probably in 2002, one of the distros, or maybe more than one, loaded block drivers prior to loading the SCSI mid layer. This meant that the cciss driver, being a block driver, could not engage the SCSI mid layer at init time without panicking, and relied on being poked by a userland program after the system was up (and the SCSI mid layer was therefore present) to engage the SCSI mid layer. This is no longer the case, and cciss can safely rely on the SCSI mid layer being present at init time and engage the SCSI mid layer straight away. This means that users will see their tape drives and medium changers at driver load time without need for a script in /etc/rc.d that does this: for x in /proc/driver/cciss/cciss* do echo "engage scsi" > $x done However, if no tape drives or medium changers are detected, the SCSI mid layer will not be engaged. If a tape drive or medium change is later hot-added to the system it will then be necessary to use the above script or similar for the device(s) to be acceesible. Signed-off-by: Stephen M. Cameron Signed-off-by: Andrew Morton Signed-off-by: Jens Axboe --- Documentation/blockdev/cciss.txt | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) (limited to 'Documentation') diff --git a/Documentation/blockdev/cciss.txt b/Documentation/blockdev/cciss.txt index 71464e0..b79d0a1 100644 --- a/Documentation/blockdev/cciss.txt +++ b/Documentation/blockdev/cciss.txt @@ -98,14 +98,12 @@ You must enable "SCSI tape drive support for Smart Array 5xxx" and "SCSI support" in your kernel configuration to be able to use SCSI tape drives with your Smart Array 5xxx controller. -Additionally, note that the driver will not engage the SCSI core at init -time. The driver must be directed to dynamically engage the SCSI core via -the /proc filesystem entry which the "block" side of the driver creates as -/proc/driver/cciss/cciss* at runtime. This is because at driver init time, -the SCSI core may not yet be initialized (because the driver is a block -driver) and attempting to register it with the SCSI core in such a case -would cause a hang. This is best done via an initialization script -(typically in /etc/init.d, but could vary depending on distribution). +Additionally, note that the driver will engage the SCSI core at init +time if any tape drives or medium changers are detected. The driver may +also be directed to dynamically engage the SCSI core via the /proc filesystem +entry which the "block" side of the driver creates as +/proc/driver/cciss/cciss* at runtime. This is best done via a script. + For example: for x in /proc/driver/cciss/cciss[0-9]* -- cgit v1.1