path: root/block/blk-settings.c
diff options
authorJens Axboe <axboe@fb.com>2014-06-10 12:53:56 -0600
committerJens Axboe <axboe@fb.com>2014-06-10 12:53:56 -0600
commit58a4915ad2f8a87f4456aac260396df7e300e6f2 (patch)
tree6481a87de33d3caa7b647c3347324eea1c474216 /block/blk-settings.c
parent2b8393b43ec672bb263009cd74c056ab01d6ac17 (diff)
block: ensure that bio_add_page() always accepts a page for an empty bio
With commit 762380ad9322 added support for chunk sizes and no merging across them, it broke the rule of always allowing adding of a single page to an empty bio. So relax the restriction a bit to allow for that, similarly to what we have always done. This fixes a crash with mkfs.xfs and 512b sector sizes on NVMe. Reported-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/blk-settings.c')
1 files changed, 4 insertions, 1 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c
index a2b9cb195e70..f1a1795a5683 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -285,7 +285,10 @@ EXPORT_SYMBOL(blk_queue_max_hw_sectors);
* Description:
* If a driver doesn't want IOs to cross a given chunk size, it can set
* this limit and prevent merging across chunks. Note that the chunk size
- * must currently be a power-of-2 in sectors.
+ * must currently be a power-of-2 in sectors. Also note that the block
+ * layer must accept a page worth of data at any offset. So if the
+ * crossing of chunks is a hard limitation in the driver, it must still be
+ * prepared to split single page bios.
void blk_queue_chunk_sectors(struct request_queue *q, unsigned int chunk_sectors)