[PATCH] scsi: if sd card is removed, do not revalidate it

[PATCH] scsi: if sd card is removed, do not revalidate it

[Yang Bai]

During revalidating, if sd card is removed, scsi_device
will be NULL, so we should not revalidate or it will cause
a panic.
This problem is report at:
http://comments.gmane.org/gmane.linux.kernel/1250235

Signed-off-by: Yang Bai <hamo.by@gmail.com>
---
 drivers/scsi/sd.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index c691fb5..470339c 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2370,10 +2370,10 @@ static int sd_revalidate_disk(struct gendisk *disk)
 				      "sd_revalidate_disk\n"));
 
 	/*
-	 * If the device is offline, don't try and read capacity or any
+	 * If the device is removed or offline, don't try and read capacity or any
 	 * of the other niceties.
 	 */
-	if (!scsi_device_online(sdp))
+	if (!sdp || !scsi_device_online(sdp))
 		goto out;
 
 	buffer = kmalloc(SD_BUF_SIZE, GFP_KERNEL);
-- 
1.7.9

Re: [PATCH] scsi: if sd card is removed, do not revalidate it

[Yang Bai]

On Tue, Feb 14, 2012 at 12:10 PM, Yang Bai <hamo.by@gmail.com> wrote:
> During revalidating, if sd card is removed, scsi_device
> will be NULL, so we should not revalidate or it will cause
> a panic.
> This problem is report at:
> http://comments.gmane.org/gmane.linux.kernel/1250235
>
> Signed-off-by: Yang Bai <hamo.by@gmail.com>
> ---
>  drivers/scsi/sd.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> index c691fb5..470339c 100644
> --- a/drivers/scsi/sd.c
> +++ b/drivers/scsi/sd.c
> @@ -2370,10 +2370,10 @@ static int sd_revalidate_disk(struct gendisk *disk)
>                                      "sd_revalidate_disk\n"));
>
>        /*
> -        * If the device is offline, don't try and read capacity or any
> +        * If the device is removed or offline, don't try and read capacity or any
>         * of the other niceties.
>         */
> -       if (!scsi_device_online(sdp))
> +       if (!sdp || !scsi_device_online(sdp))
>                goto out;
>
>        buffer = kmalloc(SD_BUF_SIZE, GFP_KERNEL);
> --
> 1.7.9
>

Is this the right way to solve this problem? Or should we add
a lock to this struct to protect it?

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    """
    Keep It Simple,Stupid.
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