On 2021/01/13 6:09, Peter Collingbourne wrote: > If extended CSD was not available, the eMMC driver would incorrectly > set the block size to 0, as the data_sector_size field of ext_csd > was never initialized. This issue was exposed by commit 817046ecddbc > ("block: Align max_hw_sectors to logical blocksize") which caused > max_sectors and max_hw_sectors to be set to 0 after setting the block > size to 0, resulting in a kernel panic in bio_split when attempting > to read from the device. Fix it by only reading the block size from > ext_csd if it is available. > > Fixes: 817046ecddbc ("block: Align max_hw_sectors to logical blocksize") > Signed-off-by: Peter Collingbourne <pcc@xxxxxxxxxx> > Link: https://linux-review.googlesource.com/id/If244d178da4d86b52034459438fec295b02d6e60 > --- > drivers/mmc/core/queue.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c > index de7cb0369c30..735cdbf1145c 100644 > --- a/drivers/mmc/core/queue.c > +++ b/drivers/mmc/core/queue.c > @@ -20,6 +20,7 @@ > #include "core.h" > #include "card.h" > #include "host.h" > +#include "mmc_ops.h" > > #define MMC_DMA_MAP_MERGE_SEGMENTS 512 > > @@ -384,7 +385,7 @@ static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card) > "merging was advertised but not possible"); > blk_queue_max_segments(mq->queue, mmc_get_max_segments(host)); > > - if (mmc_card_mmc(card)) > + if (mmc_card_mmc(card) && mmc_can_ext_csd(card)) > block_size = card->ext_csd.data_sector_size; > > blk_queue_logical_block_size(mq->queue, block_size); > This looks good to me. I wonder though if we should add a WARN() in blk_queue_logical_block_size() if it is passed a 0 block size to more easily catch this kind of bug. Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxx> -- Damien Le Moal Western Digital Research