From 3ed7897242b7efe977f3a8d06d4e5a4ebe28b10e Mon Sep 17 00:00:00 2001 From: Mike Christie Date: Wed, 11 Jun 2008 19:21:00 -0500 Subject: [PATCH] [SCSI] scsi_host regression: fix scsi host leak commit 9c7701088a61cc0cf8a6e1c68d1e74e3cc2ee0b7 Author: Dave Young Date: Tue Jan 22 14:01:34 2008 +0800 scsi: use class iteration api Isn't a correct replacement for the original hand rolled host lookup. The problem is that class_find_child would get a reference to the host's class device which is never released. Since the host class device holds a reference to the host gendev, the host can never be freed. In 2.6.26 we started using class_find_device, and this function also gets a reference to the device, so we end up with an extra ref and the host will not get released. This patch adds a put_device to balance the class_find_device() get. I kept the scsi_host_get in scsi_host_lookup, because the target layer is using scsi_host_lookup and it looks like it needs the SHOST_DEL check. Signed-off-by: Mike Christie Signed-off-by: James Bottomley --- drivers/scsi/hosts.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 3690360d7a79..c6457bfc8a49 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -456,6 +456,10 @@ static int __scsi_host_match(struct device *dev, void *data) * * Return value: * A pointer to located Scsi_Host or NULL. + * + * The caller must do a scsi_host_put() to drop the reference + * that scsi_host_get() took. The put_device() below dropped + * the reference from class_find_device(). **/ struct Scsi_Host *scsi_host_lookup(unsigned short hostnum) { @@ -463,9 +467,10 @@ struct Scsi_Host *scsi_host_lookup(unsigned short hostnum) struct Scsi_Host *shost = ERR_PTR(-ENXIO); cdev = class_find_device(&shost_class, &hostnum, __scsi_host_match); - if (cdev) + if (cdev) { shost = scsi_host_get(class_to_shost(cdev)); - + put_device(cdev); + } return shost; } EXPORT_SYMBOL(scsi_host_lookup); -- 2.20.1