Jens, Any chance to get a review for this? (Added Tested-by:) On 05/17, Jaegeuk Kim wrote: > This patch tries to avoid EAGAIN due to nrpages!=0 that was originally trying > to drop stale pages resulting in wrong data access. > > Report: https://bugs.chromium.org/p/chromium/issues/detail?id=938958#c38 > > Cc: <stable@xxxxxxxxxxxxxxx> > Cc: Jens Axboe <axboe@xxxxxxxxx> > Cc: linux-block@xxxxxxxxxxxxxxx > Cc: Bart Van Assche <bvanassche@xxxxxxx> > Fixes: 5db470e229e2 ("loop: drop caches if offset or block_size are changed") > Reported-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx> > Reported-by: grygorii tertychnyi <gtertych@xxxxxxxxx> Tested-by: Francesco Ruggeri <fruggeri@xxxxxxxxxx> > Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> > --- > v2 from v1: > - remove obsolete jump > > drivers/block/loop.c | 45 +++++++++++++++++--------------------------- > 1 file changed, 17 insertions(+), 28 deletions(-) > > diff --git a/drivers/block/loop.c b/drivers/block/loop.c > index 102d79575895..42994de2dd12 100644 > --- a/drivers/block/loop.c > +++ b/drivers/block/loop.c > @@ -1212,6 +1212,7 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) > kuid_t uid = current_uid(); > struct block_device *bdev; > bool partscan = false; > + bool drop_caches = false; > > err = mutex_lock_killable(&loop_ctl_mutex); > if (err) > @@ -1232,10 +1233,8 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) > } > > if (lo->lo_offset != info->lo_offset || > - lo->lo_sizelimit != info->lo_sizelimit) { > - sync_blockdev(lo->lo_device); > - kill_bdev(lo->lo_device); > - } > + lo->lo_sizelimit != info->lo_sizelimit) > + drop_caches = true; > > /* I/O need to be drained during transfer transition */ > blk_mq_freeze_queue(lo->lo_queue); > @@ -1265,14 +1264,6 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) > > if (lo->lo_offset != info->lo_offset || > lo->lo_sizelimit != info->lo_sizelimit) { > - /* kill_bdev should have truncated all the pages */ > - if (lo->lo_device->bd_inode->i_mapping->nrpages) { > - err = -EAGAIN; > - pr_warn("%s: loop%d (%s) has still dirty pages (nrpages=%lu)\n", > - __func__, lo->lo_number, lo->lo_file_name, > - lo->lo_device->bd_inode->i_mapping->nrpages); > - goto out_unfreeze; > - } > if (figure_loop_size(lo, info->lo_offset, info->lo_sizelimit)) { > err = -EFBIG; > goto out_unfreeze; > @@ -1317,6 +1308,12 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) > bdev = lo->lo_device; > partscan = true; > } > + > + /* truncate stale pages cached by previous operations */ > + if (!err && drop_caches) { > + sync_blockdev(lo->lo_device); > + kill_bdev(lo->lo_device); > + } > out_unlock: > mutex_unlock(&loop_ctl_mutex); > if (partscan) > @@ -1498,6 +1495,7 @@ static int loop_set_dio(struct loop_device *lo, unsigned long arg) > > static int loop_set_block_size(struct loop_device *lo, unsigned long arg) > { > + bool drop_caches = false; > int err = 0; > > if (lo->lo_state != Lo_bound) > @@ -1506,30 +1504,21 @@ static int loop_set_block_size(struct loop_device *lo, unsigned long arg) > if (arg < 512 || arg > PAGE_SIZE || !is_power_of_2(arg)) > return -EINVAL; > > - if (lo->lo_queue->limits.logical_block_size != arg) { > - sync_blockdev(lo->lo_device); > - kill_bdev(lo->lo_device); > - } > + if (lo->lo_queue->limits.logical_block_size != arg) > + drop_caches = true; > > blk_mq_freeze_queue(lo->lo_queue); > - > - /* kill_bdev should have truncated all the pages */ > - if (lo->lo_queue->limits.logical_block_size != arg && > - lo->lo_device->bd_inode->i_mapping->nrpages) { > - err = -EAGAIN; > - pr_warn("%s: loop%d (%s) has still dirty pages (nrpages=%lu)\n", > - __func__, lo->lo_number, lo->lo_file_name, > - lo->lo_device->bd_inode->i_mapping->nrpages); > - goto out_unfreeze; > - } > - > blk_queue_logical_block_size(lo->lo_queue, arg); > blk_queue_physical_block_size(lo->lo_queue, arg); > blk_queue_io_min(lo->lo_queue, arg); > loop_update_dio(lo); > -out_unfreeze: > blk_mq_unfreeze_queue(lo->lo_queue); > > + /* truncate stale pages cached by previous operations */ > + if (drop_caches) { > + sync_blockdev(lo->lo_device); > + kill_bdev(lo->lo_device); > + } > return err; > } > > -- > 2.19.0.605.g01d371f741-goog > > > > _______________________________________________ > Linux-f2fs-devel mailing list > Linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
