From 719c15a75ebf3bda3ca718fe8e0ce63d262ec7ae Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 6 May 2024 06:20:27 +0200 Subject: [PATCH] blk-lib: check for kill signal in ioctl BLKDISCARD Discards can access a significant capacity and take longer than the user expected. A user may change their mind about wanting to run that command and attempt to kill the process and do something else with their device. But since the task is uninterruptable, they have to wait for it to finish, which could be many hours. Open code blkdev_issue_discard in the BLKDISCARD ioctl handler and check for a fatal signal at each iteration so the user doesn't have to wait for their regretted operation to complete naturally. Heavily based on an earlier patch from Keith Busch. Reported-by: Conrad Meyer Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20240506042027.2289826-7-hch@lst.de Signed-off-by: Jens Axboe --- block/ioctl.c | 33 ++++++++++++++++++++++++++++++--- 1 file changed, 30 insertions(+), 3 deletions(-) diff --git a/block/ioctl.c b/block/ioctl.c index 49fa02b17ec1..d7a6c6931a1e 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -96,9 +96,11 @@ static int blk_ioctl_discard(struct block_device *bdev, blk_mode_t mode, unsigned long arg) { unsigned int bs_mask = bdev_logical_block_size(bdev) - 1; - uint64_t range[2]; - uint64_t start, len; struct inode *inode = bdev->bd_inode; + uint64_t range[2], start, len; + struct bio *prev = NULL, *bio; + sector_t sector, nr_sects; + struct blk_plug plug; int err; if (!(mode & BLK_OPEN_WRITE)) @@ -127,7 +129,32 @@ static int blk_ioctl_discard(struct block_device *bdev, blk_mode_t mode, err = truncate_bdev_range(bdev, mode, start, start + len - 1); if (err) goto fail; - err = blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL); + + sector = start >> SECTOR_SHIFT; + nr_sects = len >> SECTOR_SHIFT; + + blk_start_plug(&plug); + while (1) { + if (fatal_signal_pending(current)) { + if (prev) + bio_await_chain(prev); + err = -EINTR; + goto out_unplug; + } + bio = blk_alloc_discard_bio(bdev, §or, &nr_sects, + GFP_KERNEL); + if (!bio) + break; + prev = bio_chain_and_submit(prev, bio); + } + if (prev) { + err = submit_bio_wait(prev); + if (err == -EOPNOTSUPP) + err = 0; + bio_put(prev); + } +out_unplug: + blk_finish_plug(&plug); fail: filemap_invalidate_unlock(inode->i_mapping); return err;