Module reference counting appropriately occurs when the block device is opened, but dm devices exist outside of the device actually being opened. Currently, in certain situations, unloading the dm-mod module will result in an oops. This patch claims a reference to the module when a device is created, and drops it when the device is freed. This is one possible implementation. Another could be to do an internal "dmsetup remove_all" when the module is unloaded. Comments welcome. Signed-off-by: Jeff Mahoney <jeffm@xxxxxxxx> -- drivers/md/dm.c | 6 ++++++ 1 files changed, 6 insertions(+) diff -ruNpX ../dontdiff 2.6.17-rc1-staging1/drivers/md/dm.c 2.6.17-rc1-staging2/drivers/md/dm.c --- 2.6.17-rc1-staging1/drivers/md/dm.c 2006-04-17 10:51:49.000000000 -0400 +++ 2.6.17-rc1-staging2/drivers/md/dm.c 2006-04-17 10:51:49.000000000 -0400 @@ -846,6 +846,9 @@ static struct mapped_device *alloc_dev(u return NULL; } + if (!try_module_get(THIS_MODULE)) + goto bad0; + /* get a minor number for the dev */ r = persistent ? specific_minor(md, minor) : next_free_minor(md, &minor); if (r < 0) @@ -912,6 +915,8 @@ static struct mapped_device *alloc_dev(u blk_cleanup_queue(md->queue); free_minor(minor); bad1: + module_put(THIS_MODULE); + bad0: kfree(md); return NULL; } @@ -935,6 +940,7 @@ static void free_dev(struct mapped_devic put_disk(md->disk); blk_cleanup_queue(md->queue); + module_put(THIS_MODULE); kfree(md); } -- dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
