From: Paul Mackerras Date: Sat, 26 Sep 2015 00:19:15 +0000 (+1000) Subject: scsi_dh: Use the correct module name when loading device handler X-Git-Tag: omap-for-v4.3/fixes-rc5~9^2~1 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1378889c563a2938d231203ed36c041af183b798;p=pandora-kernel.git scsi_dh: Use the correct module name when loading device handler This fixes a bug in recent kernels which results in failure to boot on systems that have multipath SCSI disks. I observed this failure on a POWER8 server where all the disks are multipath SCSI disks. The symptoms are several messages like this on the console: [ 3.018700] device-mapper: table: 253:0: multipath: error attaching hardware handler [ 3.018828] device-mapper: ioctl: error adding target to table and the system does not find its disks, and therefore fails to boot. Bisection revealed that the bug was introduced in commit 566079c849cf, "dm-mpath, scsi_dh: request scsi_dh modules in scsi_dh, not dm-mpath". The specific reason for the failure is that where we previously loaded the "scsi_dh_alua" module, we are now trying to load the "alua" module, which doesn't exist. To fix this, we change the request_module call in scsi_dh_lookup() to prepend "scsi_dh_" to the name, just like the old code in drivers/md/dm-mpath.c:parse_hw_handler() used to do. [jejb: also fixes issue spotted by Sasha Levin that formatting characters could be passed in via sysfs and cause issues with request_module()] Fixes: 566079c849cf Signed-off-by: Paul Mackerras Cc: Sasha Levin Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Signed-off-by: James Bottomley --- Reading git-diff-tree failed