block: make sure discard bio is aligned with logical block size

BugLink: https://bugs.launchpad.net/bugs/1836802
commit 1adfc5e4136f5967d591c399aff95b3b035f16b7 upstream.

Obviously the created discard bio has to be aligned with logical block size.

This patch introduces the helper of bio_allowed_max_sectors() for
this purpose.

Cc: stable@vger.kernel.org
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Xiao Ni <xni@redhat.com>
Cc: Mariusz Dabrowski <mariusz.dabrowski@intel.com>
Fixes: 744889b7cbb56a6 ("block: don't deal with discard limit in blkdev_issue_discard()")
Fixes: a22c4d7e34402cc ("block: re-add discard_granularity and alignment checks")
Reported-by: Rui Salvaterra <rsalvaterra@gmail.com>
Tested-by: Rui Salvaterra <rsalvaterra@gmail.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/block/blk-lib.c b/block/blk-lib.c
index 874df58f7cb5a78a4f89982c2a5d1b5fc1c362eb..b80e01d0c960e793f146669773dbf16a4c1bccae 100644 (file)
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -53,6 +53,8 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
                unsigned int req_sects = nr_sects;
                sector_t end_sect;
 
+               req_sects = min(req_sects, bio_allowed_max_sectors(q));
+
                end_sect = sector + req_sects;
 
                bio = next_bio(bio, 0, gfp_mask);

diff --git a/block/blk-merge.c b/block/blk-merge.c
index 8d60a5bbcef930d514cc3a75a273bc3506922904..f452ccc610602b21a95154fc0ee5a51f3509550e 100644 (file)
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -27,7 +27,8 @@ static struct bio *blk_bio_discard_split(struct request_queue *q,
        /* Zero-sector (unknown) and one-sector granularities are the same.  */
        granularity = max(q->limits.discard_granularity >> 9, 1U);
 
-       max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
+       max_discard_sectors = min(q->limits.max_discard_sectors,
+                       bio_allowed_max_sectors(q));
        max_discard_sectors -= max_discard_sectors % granularity;
 
        if (unlikely(!max_discard_sectors)) {

diff --git a/block/blk.h b/block/blk.h
index 442098aa9463a37dad0dfccb1718eea65be6cdb3..e8d598e4a948de5d4e5d9ff298166b2fb6cacbc0 100644 (file)
--- a/block/blk.h
+++ b/block/blk.h
@@ -245,6 +245,16 @@ static inline void req_set_nomerge(struct request_queue *q, struct request *req)
                q->last_merge = NULL;
 }
 
+/*
+ * The max size one bio can handle is UINT_MAX becasue bvec_iter.bi_size
+ * is defined as 'unsigned int', meantime it has to aligned to with logical
+ * block size which is the minimum accepted unit by hardware.
+ */
+static inline unsigned int bio_allowed_max_sectors(struct request_queue *q)
+{
+       return round_down(UINT_MAX, queue_logical_block_size(q)) >> 9;
+}
+
 /*
  * Internal io_context interface
  */