From acd054a5ef401e03e0047b487e572442614f81e5 Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Fri, 26 Oct 2007 13:59:44 +0200 Subject: [PATCH] Initialise scatter/gather list in ata_sg_setup After turning on DEBUG_SG I hit a fail: kernel BUG at include/linux/scatterlist.h:50! ata_qc_issue ata_scsi_translate ipr_queuecommand scsi_dispatch_cmd scsi_request_fn elv_insert blk_execute_rq_nowait blk_execute_rq sg_io scsi_cmd_ioctl cdrom_ioctl sr_block_ioctl blkdev_driver_ioctl blkdev_ioctl block_ioctl do_ioctl vfs_ioctl sys_ioctl sg_ioctl_trans It looks like ata_sg_setup is working on an uninitialised sg table. Call sg_init_table to initialise it before use. Signed-off-by: Anton Blanchard Note: this patch will fix it, but you could also get away with just doing the sg_init_table() once at qc creation time. Signed-off-by: Jens Axboe --- drivers/ata/libata-core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 081e3df..7ef515b 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -4689,6 +4689,7 @@ static int ata_sg_setup(struct ata_queued_cmd *qc) * data in this function or read data in ata_sg_clean. */ offset = lsg->offset + lsg->length - qc->pad_len; + sg_init_table(psg, 1); sg_set_page(psg, nth_page(sg_page(lsg), offset >> PAGE_SHIFT), qc->pad_len, offset_in_page(offset)); -- 2.7.4