From c5b2751c1bd98bcab5f79bba0c771ef641c14283 Mon Sep 17 00:00:00 2001 From: Michael Reed Date: Mon, 20 Sep 2010 11:20:22 -0500 Subject: [PATCH] sd name space exhaustion causes system hang commit 1a03ae0f556a931aa3747b70e44b78308f5b0590 upstream. Following a site power outage which re-enabled all the ports on my FC switches, my system subsequently booted with far too many luns! I had let it run hoping it would make multi-user. It didn't. :( It hung solid after exhausting the last sd device, sdzzz, and attempting to create sdaaaa and beyond. I was unable to get a dump. Discovered using a 2.6.32.13 based system. correct this by detecting when the last index is utilized and failing the sd probe of the device. Patch applies to scsi-misc-2.6. Signed-off-by: Michael Reed Signed-off-by: James Bottomley Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/sd.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 8802e48bc063..e4d9c515c292 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -2204,11 +2204,10 @@ static void sd_probe_async(void *data, async_cookie_t cookie) index = sdkp->index; dev = &sdp->sdev_gendev; - if (index < SD_MAX_DISKS) { - gd->major = sd_major((index & 0xf0) >> 4); - gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00); - gd->minors = SD_MINORS; - } + gd->major = sd_major((index & 0xf0) >> 4); + gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00); + gd->minors = SD_MINORS; + gd->fops = &sd_fops; gd->private_data = &sdkp->driver; gd->queue = sdkp->device->request_queue; @@ -2297,6 +2296,12 @@ static int sd_probe(struct device *dev) if (error) goto out_put; + if (index >= SD_MAX_DISKS) { + error = -ENODEV; + sdev_printk(KERN_WARNING, sdp, "SCSI disk (sd) name space exhausted.\n"); + goto out_free_index; + } + error = sd_format_disk_name("sd", index, gd->disk_name, DISK_NAME_LEN); if (error) goto out_free_index; -- 2.39.5