kernel.git/include/linux/bio.h, branch linux-5.12.y

block: return the correct bvec when checking for gaps

2021-07-14T15:00:31Z

commit c9c9762d4d44dcb1b2ba90cfb4122dc11ceebf31 upstream. After commit 07173c3ec276 ("block: enable multipage bvecs"), a bvec can have multiple pages. But bio_will_gap() still assumes one page bvec while checking for merging. If the pages in the bvec go across the seg_boundary_mask, this check for merging can potentially succeed if only the 1st page is tested, and can fail if all the pages are tested. Later, when SCSI builds the SG list the same check for merging is done in __blk_segment_map_sg_merge() with all the pages in the bvec tested. This time the check may fail if the pages in bvec go across the seg_boundary_mask (but tested okay in bio_will_gap() earlier, so those BIOs were merged). If this check fails, we end up with a broken SG list for drivers assuming the SG list not having offsets in intermediate pages. This results in incorrect pages written to the disk. Fix this by returning the multi-page bvec when testing gaps for merging. Cc: Jens Axboe Cc: Johannes Thumshirn Cc: Pavel Begunkov Cc: Ming Lei Cc: Tejun Heo Cc: "Matthew Wilcox (Oracle)" Cc: Jeffle Xu Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Fixes: 07173c3ec276 ("block: enable multipage bvecs") Signed-off-by: Long Li Reviewed-by: Ming Lei Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/1623094445-22332-1-git-send-email-longli@linuxonhyperv.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

block: rename BIO_MAX_PAGES to BIO_MAX_VECS

2021-03-11T14:47:48Z

Ever since the addition of multipage bio_vecs BIO_MAX_PAGES has been horribly confusingly misnamed. Rename it to BIO_MAX_VECS to stop confusing users of the bio API. Signed-off-by: Christoph Hellwig Reviewed-by: Matthew Wilcox (Oracle) Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/r/20210311110137.1132391-2-hch@lst.de Signed-off-by: Jens Axboe

block: Add bio_max_segs

2021-02-26T22:49:51Z

It's often inconvenient to use BIO_MAX_PAGES due to min() requiring the sign to be the same. Introduce bio_max_segs() and change BIO_MAX_PAGES to be unsigned to make it easier for the users. Reviewed-by: Chaitanya Kulkarni Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Jens Axboe

Merge tag 'for-5.12/block-2021-02-17' of git://git.kernel.dk/linux-block

2021-02-21T19:02:48Z

Pull core block updates from Jens Axboe: "Another nice round of removing more code than what is added, mostly due to Christoph's relentless pursuit of tech debt removal/cleanups. This pull request contains: - Two series of BFQ improvements (Paolo, Jan, Jia) - Block iov_iter improvements (Pavel) - bsg error path fix (Pan) - blk-mq scheduler improvements (Jan) - -EBUSY discard fix (Jan) - bvec allocation improvements (Ming, Christoph) - bio allocation and init improvements (Christoph) - Store bdev pointer in bio instead of gendisk + partno (Christoph) - Block trace point cleanups (Christoph) - hard read-only vs read-only split (Christoph) - Block based swap cleanups (Christoph) - Zoned write granularity support (Damien) - Various fixes/tweaks (Chunguang, Guoqing, Lei, Lukas, Huhai)" * tag 'for-5.12/block-2021-02-17' of git://git.kernel.dk/linux-block: (104 commits) mm: simplify swapdev_block sd_zbc: clear zone resources for non-zoned case block: introduce blk_queue_clear_zone_settings() zonefs: use zone write granularity as block size block: introduce zone_write_granularity limit block: use blk_queue_set_zoned in add_partition() nullb: use blk_queue_set_zoned() to setup zoned devices nvme: cleanup zone information initialization block: document zone_append_max_bytes attribute block: use bi_max_vecs to find the bvec pool md/raid10: remove dead code in reshape_request block: mark the bio as cloned in bio_iov_bvec_set block: set BIO_NO_PAGE_REF in bio_iov_bvec_set block: remove a layer of indentation in bio_iov_iter_get_pages block: turn the nr_iovecs argument to bio_alloc* into an unsigned short block: remove the 1 and 4 vec bvec_slabs entries block: streamline bvec_alloc block: factor out a bvec_alloc_gfp helper block: move struct biovec_slab to bio.c block: reuse BIO_INLINE_VECS for integrity bvecs ...

block: add bio_add_zone_append_page

2021-02-08T23:52:19Z

Add bio_add_zone_append_page(), a wrapper around bio_add_hw_page() which is intended to be used by file systems that directly add pages to a bio instead of using bio_iov_iter_get_pages(). Reviewed-by: Christoph Hellwig Reviewed-by: Josef Bacik Reviewed-by: Chaitanya Kulkarni Acked-by: Jens Axboe Signed-off-by: Johannes Thumshirn Signed-off-by: David Sterba

block: use bi_max_vecs to find the bvec pool

2021-02-08T15:33:16Z

Instead of encoding of the bvec pool using magic bio flags, just use a helper to find the pool based on the max_vecs value. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: turn the nr_iovecs argument to bio_alloc* into an unsigned short

2021-02-08T15:33:16Z

The bi_max_vecs and bi_vcnt fields are defined as unsigned short, so don't allow passing larger values in. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: move struct biovec_slab to bio.c

2021-02-08T15:33:16Z

struct biovec_slab is only used inside of bio.c, so move it there. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: split bio_kmalloc from bio_alloc_bioset

2021-01-27T16:51:48Z

bio_kmalloc shares almost no logic with the bio_set based fast path in bio_alloc_bioset. Split it into an entirely separate implementation. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Chaitanya Kulkarni Acked-by: Damien Le Moal Signed-off-by: Jens Axboe

bio: don't copy bvec for direct IO

2021-01-25T15:58:24Z

The block layer spends quite a while in blkdev_direct_IO() to copy and initialise bio's bvec. However, if we've already got a bvec in the input iterator it might be reused in some cases, i.e. when new ITER_BVEC_FLAG_FIXED flag is set. Simple tests show considerable performance boost, and it also reduces memory footprint. Suggested-by: Matthew Wilcox Reviewed-by: Christoph Hellwig Signed-off-by: Pavel Begunkov Reviewed-by: Ming Lei Signed-off-by: Jens Axboe