From d873884783edb0d18666dad28841695a4e57459c Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Tue, 9 Feb 2021 10:56:20 -0500 Subject: [PATCH] dm writecache: fix writing beyond end of underlying device when shrinking commit 4134455f2aafdfeab50cabb4cccb35e916034b93 upstream. Do not attempt to write any data beyond the end of the underlying data device while shrinking it. The DM writecache device must be suspended when the underlying data device is shrunk. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-writecache.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c index 08ae59a6e873..4c2971835d33 100644 --- a/drivers/md/dm-writecache.c +++ b/drivers/md/dm-writecache.c @@ -142,6 +142,7 @@ struct dm_writecache { size_t metadata_sectors; size_t n_blocks; uint64_t seq_count; + sector_t data_device_sectors; void *block_start; struct wc_entry *entries; unsigned block_size; @@ -918,6 +919,8 @@ static void writecache_resume(struct dm_target *ti) wc_lock(wc); + wc->data_device_sectors = i_size_read(wc->dev->bdev->bd_inode) >> SECTOR_SHIFT; + if (WC_MODE_PMEM(wc)) { persistent_memory_invalidate_cache(wc->memory_map, wc->memory_map_size); } else { @@ -1488,6 +1491,10 @@ static bool wc_add_block(struct writeback_struct *wb, struct wc_entry *e, gfp_t void *address = memory_data(wc, e); persistent_memory_flush_cache(address, block_size); + + if (unlikely(bio_end_sector(&wb->bio) >= wc->data_device_sectors)) + return true; + return bio_add_page(&wb->bio, persistent_memory_page(address), block_size, persistent_memory_page_offset(address)) != 0; } @@ -1559,6 +1566,9 @@ static void __writecache_writeback_pmem(struct dm_writecache *wc, struct writeba if (writecache_has_error(wc)) { bio->bi_status = BLK_STS_IOERR; bio_endio(bio); + } else if (unlikely(!bio_sectors(bio))) { + bio->bi_status = BLK_STS_OK; + bio_endio(bio); } else { submit_bio(bio); } @@ -1602,6 +1612,14 @@ static void __writecache_writeback_ssd(struct dm_writecache *wc, struct writebac e = f; } + if (unlikely(to.sector + to.count > wc->data_device_sectors)) { + if (to.sector >= wc->data_device_sectors) { + writecache_copy_endio(0, 0, c); + continue; + } + from.count = to.count = wc->data_device_sectors - to.sector; + } + dm_kcopyd_copy(wc->dm_kcopyd, &from, 1, &to, 0, writecache_copy_endio, c); __writeback_throttle(wc, wbl);