From a5426af719d536a41e90b8da9964ef66f273dadd Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Fri, 1 Oct 2010 14:19:55 -0700 Subject: [PATCH] Staging: zram: work around oops due to startup ordering snafu I'm getting an oops when running mkfs on zram: NIP [d0000000030e0340] .zram_inc_stat+0x58/0x84 [zram] [c00000006d58f720] [d0000000030e091c] .zram_make_request+0xa8/0x6a0 [zram] [c00000006d58f840] [c00000000035795c] .generic_make_request+0x390/0x434 [c00000006d58f950] [c000000000357b14] .submit_bio+0x114/0x140 [c00000006d58fa20] [c000000000361778] .blkdev_issue_discard+0x1ac/0x250 [c00000006d58fb10] [c000000000361f68] .blkdev_ioctl+0x358/0x7fc [c00000006d58fbd0] [c0000000001c1c1c] .block_ioctl+0x6c/0x90 [c00000006d58fc70] [c0000000001984c4] .do_vfs_ioctl+0x660/0x6d4 [c00000006d58fd70] [c0000000001985a0] .SyS_ioctl+0x68/0xb0 Since disksize no longer starts as 0 it looks like we can call zram_make_request before the device has been initialised. The patch below fixes the immediate problem but this would go away if we move the initialisation function elsewhere (as suggested in another thread). Signed-off-by: Anton Blanchard Cc: Nitin Gupta Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- drivers/staging/zram/zram_drv.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c index c5f84ee3d28a9..72f1b9ce577b3 100644 --- a/drivers/staging/zram/zram_drv.c +++ b/drivers/staging/zram/zram_drv.c @@ -435,6 +435,12 @@ static int zram_make_request(struct request_queue *queue, struct bio *bio) int ret = 0; struct zram *zram = queue->queuedata; + if (unlikely(!zram->init_done)) { + set_bit(BIO_UPTODATE, &bio->bi_flags); + bio_endio(bio, 0); + return 0; + } + if (!valid_io_request(zram, bio)) { zram_stat64_inc(zram, &zram->stats.invalid_io); bio_io_error(bio); -- 2.39.5