Re: [PATCH] mmc: Add missing sg_init_table() call

From: Andrew Morton
Date: Tue Nov 27 2007 - 00:30:49 EST


On Thu, 22 Nov 2007 20:32:51 +0100 Haavard Skinnemoen <hskinnemoen@xxxxxxxxx> wrote:

> mmc_init_queue only initializes the scatterlists with sg_init_table()
> when using a bounce buffer. This leads to a BUG() when CONFIG_DEBUG_SG
> is set.
>

I assume that 2.6.23 is not afflicted in this way?

> ---
> drivers/mmc/card/queue.c | 3 ++-
> 1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
> index 1b9c9b6..30cd13b 100644
> --- a/drivers/mmc/card/queue.c
> +++ b/drivers/mmc/card/queue.c
> @@ -180,12 +180,13 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock
> blk_queue_max_hw_segments(mq->queue, host->max_hw_segs);
> blk_queue_max_segment_size(mq->queue, host->max_seg_size);
>
> - mq->sg = kzalloc(sizeof(struct scatterlist) *
> + mq->sg = kmalloc(sizeof(struct scatterlist) *
> host->max_phys_segs, GFP_KERNEL);
> if (!mq->sg) {
> ret = -ENOMEM;
> goto cleanup_queue;
> }
> + sg_init_table(mq->sg, host->max_phys_segs);
> }
>
> init_MUTEX(&mq->thread_sem);

Pierre, I can queue this up but if you merge it into your tree I shall drop
it and shall lose track of it. So it's then all down to you to remember to
get the fix into 2.6.24.

(Except this particular bug looks like a post-2.6.23 regression, so I can cc
the Rafael which never forgets, so it will then get tracked all the way into
Linus's tree)

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