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| author | Jens Axboe <axboe@fb.com> | 2014-06-10 12:53:56 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2014-06-10 12:53:56 -0600 |
| commit | 58a4915ad2f8a87f4456aac260396df7e300e6f2 (patch) | |
| tree | 6481a87de33d3caa7b647c3347324eea1c474216 /block | |
| parent | 2b8393b43ec672bb263009cd74c056ab01d6ac17 (diff) | |
| download | lwn-58a4915ad2f8a87f4456aac260396df7e300e6f2.tar.gz lwn-58a4915ad2f8a87f4456aac260396df7e300e6f2.zip | |
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')
| -rw-r--r-- | block/bio.c | 7 | ||||
| -rw-r--r-- | block/blk-settings.c | 5 |
2 files changed, 10 insertions, 2 deletions
diff --git a/block/bio.c b/block/bio.c index 97e832cc9b9c..2d64488e51c6 100644 --- a/block/bio.c +++ b/block/bio.c @@ -849,8 +849,13 @@ int bio_add_page(struct bio *bio, struct page *page, unsigned int len, unsigned int offset) { struct request_queue *q = bdev_get_queue(bio->bi_bdev); + unsigned int max_sectors; - return __bio_add_page(q, bio, page, len, offset, blk_max_size_offset(q, bio->bi_iter.bi_sector)); + max_sectors = blk_max_size_offset(q, bio->bi_iter.bi_sector); + if ((max_sectors < (len >> 9)) && !bio->bi_iter.bi_size) + max_sectors = len >> 9; + + return __bio_add_page(q, bio, page, len, offset, max_sectors); } EXPORT_SYMBOL(bio_add_page); 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) { |