user/sven/linux.git/include/linux/bio.h, branch v5.4.276

block: return the correct bvec when checking for gaps

2021-07-14T14:53:48Z

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: add bio_truncate to fix guard_bio_eod

2020-01-09T09:19:54Z

[ Upstream commit 85a8ce62c2eabe28b9d76ca4eecf37922402df93 ] Some filesystem, such as vfat, may send bio which crosses device boundary, and the worse thing is that the IO request starting within device boundaries can contain more than one segment past EOD. Commit dce30ca9e3b6 ("fs: fix guard_bio_eod to check for real EOD errors") tries to fix this issue by returning -EIO for this situation. However, this way lets fs user code lose chance to handle -EIO, then sync_inodes_sb() may hang for ever. Also the current truncating on last segment is dangerous by updating the last bvec, given bvec table becomes not immutable any more, and fs bio users may not retrieve the truncated pages via bio_for_each_segment_all() in its .end_io callback. Fixes this issue by supporting multi-segment truncating. And the approach is simpler: - just update bio size since block layer can make correct bvec with the updated bio size. Then bvec table becomes really immutable. - zero all truncated segments for read bio Cc: Carlos Maiolino Cc: linux-fsdevel@vger.kernel.org Fixed-by: dce30ca9e3b6 ("fs: fix guard_bio_eod to check for real EOD errors") Reported-by: syzbot+2b9e54155c8c25d8d165@syzkaller.appspotmail.com Signed-off-by: Ming Lei Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: fix .bi_size overflow

2019-07-01T14:18:54Z

'bio->bi_iter.bi_size' is 'unsigned int', which at most hold 4G - 1 bytes. Before 07173c3ec276 ("block: enable multipage bvecs"), one bio can include very limited pages, and usually at most 256, so the fs bio size won't be bigger than 1M bytes most of times. Since we support multi-page bvec, in theory one fs bio really can be added > 1M pages, especially in case of hugepage, or big writeback with too many dirty pages. Then there is chance in which .bi_size is overflowed. Fixes this issue by using bio_full() to check if the added segment may overflow .bi_size. Cc: Liu Yiding Cc: kernel test robot Cc: "Darrick J. Wong" Cc: linux-xfs@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: stable@vger.kernel.org Fixes: 07173c3ec276 ("block: enable multipage bvecs") Reviewed-by: Christoph Hellwig Signed-off-by: Ming Lei Signed-off-by: Jens Axboe

Merge tag 'v5.2-rc6' into for-5.3/block

2019-07-01T14:16:08Z

Merge 5.2-rc6 into for-5.3/block, so we get the same page merge leak fix. Otherwise we end up having conflicts with future patches between for-5.3/block and master that touch this area. In particular, it makes the bio_full() fix hard to backport to stable. * tag 'v5.2-rc6': (482 commits) Linux 5.2-rc6 Revert "iommu/vt-d: Fix lock inversion between iommu->lock and device_domain_lock" Bluetooth: Fix regression with minimum encryption key size alignment tcp: refine memory limit test in tcp_fragment() x86/vdso: Prevent segfaults due to hoisted vclock reads SUNRPC: Fix a credential refcount leak Revert "SUNRPC: Declare RPC timers as TIMER_DEFERRABLE" net :sunrpc :clnt :Fix xps refcount imbalance on the error path NFS4: Only set creation opendata if O_CREAT ARM: 8867/1: vdso: pass --be8 to linker if necessary KVM: nVMX: reorganize initial steps of vmx_set_nested_state KVM: PPC: Book3S HV: Invalidate ERAT when flushing guest TLB entries habanalabs: use u64_to_user_ptr() for reading user pointers nfsd: replace Jeff by Chuck as nfsd co-maintainer inet: clear num_timeout reqsk_alloc() PCI/P2PDMA: Ignore root complex whitelist when an IOMMU is present net: mvpp2: debugfs: Add pmap to fs dump ipv6: Default fib6_type to RTN_UNICAST when not set net: hns3: Fix inconsistent indenting net/af_iucv: always register net_device notifier ...

block: optionally mark pages dirty in bio_release_pages

2019-06-29T15:47:31Z

A lot of callers of bio_release_pages also want to mark the released pages as dirty. Add a mark_dirty parameter to avoid a second relatively expensive bio_for_each_segment_all loop. Reviewed-by: Minwoo Im Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: move the BIO_NO_PAGE_REF check into bio_release_pages

2019-06-29T15:47:31Z

Move the BIO_NO_PAGE_REF check into bio_release_pages instead of duplicating it in both callers. Also make the function available outside of bio.c so that we can reuse it in other direct I/O implementations. Reviewed-by: Minwoo Im Reviewed-by: Johannes Thumshirn Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: Remove unused code

2019-06-27T13:34:25Z

bio_flush_dcache_pages() is unused. Remove it. Reviewed-by: Christoph Hellwig Signed-off-by: Damien Le Moal Signed-off-by: Jens Axboe

block: remove the bi_phys_segments field in struct bio

2019-06-20T16:29:22Z

We only need the number of segments in the blk-mq submission path. Remove the field from struct bio, and return it from a variant of blk_queue_split instead of that it can passed as an argument to those functions that need the value. This also means we stop recounting segments except for cloning and partial segments. To keep the number of arguments in this how path down remove pointless struct request_queue arguments from any of the functions that had it and grew a nr_segs argument. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: return from __bio_try_merge_page if merging occured in the same page

2019-06-17T15:33:02Z

We currently have an input same_page parameter to __bio_try_merge_page to prohibit merging in the same page. The rationale for that is that some callers need to account for every page added to a bio. Instead of letting these callers call twice into the merge code to account for the new vs existing page cases, just turn the paramter into an output one that returns if a merge in the same page occured and let them act accordingly. Signed-off-by: Christoph Hellwig Reviewed-by: Ming Lei Signed-off-by: Jens Axboe

bio: fix improper use of smp_mb__before_atomic()

2019-05-23T16:25:26Z

This barrier only applies to the read-modify-write operations; in particular, it does not apply to the atomic_set() primitive. Replace the barrier with an smp_mb(). Fixes: dac56212e8127 ("bio: skip atomic inc/dec of ->bi_cnt for most use cases") Cc: stable@vger.kernel.org Reported-by: "Paul E. McKenney" Reported-by: Peter Zijlstra Signed-off-by: Andrea Parri Reviewed-by: Ming Lei Cc: Jens Axboe Cc: Ming Lei Cc: linux-block@vger.kernel.org Cc: "Paul E. McKenney" Cc: Peter Zijlstra Signed-off-by: Jens Axboe