From: Jay Vosburgh Date: Sat, 20 Jan 2007 02:15:47 +0000 (-0800) Subject: bonding: modify sysfs support to permit multiple loads X-Git-Tag: v2.6.21-rc1~92^2~31^2~58 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=877cbd36b27e073eb78fe7073a433fbe0da7d5f8;p=linux-2.6 bonding: modify sysfs support to permit multiple loads The existing code would blindly attempt to create the bonding_masters file (in /sys/class/net) every time the module was loaded. When the module is loaded multiple times (which is the historical method used by initscripts and sysconfig to create multiple bonding interfaces), this caused load failure of the second module load attempt, as the creation request would fail. This changes the code to note the failure, arrange to not remove the bonding_masters file upon module exit, and then return success. Bonding interfaces created by the second or subsequent loads of the module will not exist in bonding_masters. This is not a significant change, as previously only the interfaces from the most recent load of the module would be listed. Both situations are less than optimal, but this case permits compatibility with existing distro configuration scripts, and is consistent. Note that previously, the sysfs create request would overwrite the exsting bonding_masters file and succeed, allowing multiple loads of the module. The sysfs code has recently changed to return an error if the file being created already exists. Patrick McHardy , who reported this problem, observed crashes on the old kernel (before sysfs checked for duplicates). I did not experience such crashes, but this change should resolve them. Signed-off-by: Jay Vosburgh Signed-off-by: Jeff Garzik --- diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c index ced9ed8f99..8e317e1155 100644 --- a/drivers/net/bonding/bond_sysfs.c +++ b/drivers/net/bonding/bond_sysfs.c @@ -1372,6 +1372,21 @@ int bond_create_sysfs(void) return -ENODEV; ret = class_create_file(netdev_class, &class_attr_bonding_masters); + /* + * Permit multiple loads of the module by ignoring failures to + * create the bonding_masters sysfs file. Bonding devices + * created by second or subsequent loads of the module will + * not be listed in, or controllable by, bonding_masters, but + * will have the usual "bonding" sysfs directory. + * + * This is done to preserve backwards compatibility for + * initscripts/sysconfig, which load bonding multiple times to + * configure multiple bonding devices. + */ + if (ret == -EEXIST) { + netdev_class = NULL; + return 0; + } return ret;