kernel/linux.git/block/blk-map.c, branch v6.6.131

block: fix sanity checks in blk_rq_map_user_bvec

2024-11-08T15:28:24+00:00

[ Upstream commit 2ff949441802a8d076d9013c7761f63e8ae5a9bd ] blk_rq_map_user_bvec contains a check bytes + bv->bv_len > nr_iter which causes unnecessary failures in NVMe passthrough I/O, reproducible as follows: - register a 2 page, page-aligned buffer against a ring - use that buffer to do a 1 page io_uring NVMe passthrough read The second (i = 1) iteration of the loop in blk_rq_map_user_bvec will then have nr_iter == 1 page, bytes == 1 page, bv->bv_len == 1 page, so the check bytes + bv->bv_len > nr_iter will succeed, causing the I/O to fail. This failure is unnecessary, as when the check succeeds, it means we've checked the entire buffer that will be used by the request - i.e. blk_rq_map_user_bvec should complete successfully. Therefore, terminate the loop early and return successfully when the check bytes + bv->bv_len > nr_iter succeeds. While we're at it, also remove the check that all segments in the bvec are single-page. While this seems to be true for all users of the function, it doesn't appear to be required anywhere downstream. CC: stable@vger.kernel.org Signed-off-by: Xinyu Zhang Co-developed-by: Uday Shankar Signed-off-by: Uday Shankar Fixes: 37987547932c ("block: extend functionality to map bvec iterator") Link: https://lore.kernel.org/r/20241023211519.4177873-1-ushankar@purestorage.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: Fix WARNING in _copy_from_iter

2024-03-01T12:34:49+00:00

[ Upstream commit 13f3956eb5681a4045a8dfdef48df5dc4d9f58a6 ] Syzkaller reports a warning in _copy_from_iter because an iov_iter is supposedly used in the wrong direction. The reason is that syzcaller managed to generate a request with a transfer direction of SG_DXFER_TO_FROM_DEV. This instructs the kernel to copy user buffers into the kernel, read into the copied buffers and then copy the data back to user space. Thus the iovec is used in both directions. Detect this situation in the block layer and construct a new iterator with the correct direction for the copy-in. Reported-by: syzbot+a532b03fdfee2c137666@syzkaller.appspotmail.com Closes: https://lore.kernel.org/lkml/0000000000009b92c10604d7a5e9@google.com/t/ Reported-by: syzbot+63dec323ac56c28e644f@syzkaller.appspotmail.com Closes: https://lore.kernel.org/lkml/0000000000003faaa105f6e7c658@google.com/T/ Signed-off-by: Christian A. Ehrhardt Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20240121202634.275068-1-lk@c--e.de Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: fix pin count management when merging same-page segments

2023-09-06T13:32:27+00:00

There is no need to unpin the added page when adding it to the bio fails as that is done by the loop below. Instead we want to unpin it when adding a single page to the bio more than once as bio_release_pages will only unpin it once. Fixes: d1916c86ccdc ("block: move same page handling from __bio_add_pc_page to the callers") Signed-off-by: Christoph Hellwig Reviewed-by: Damien Le Moal Link: https://lore.kernel.org/r/20230905124731.328255-1-hch@lst.de Signed-off-by: Jens Axboe

Merge tag 'for-6.5/block-2023-06-23' of git://git.kernel.dk/linux

2023-06-26T19:47:20+00:00

Pull block updates from Jens Axboe: - NVMe pull request via Keith: - Various cleanups all around (Irvin, Chaitanya, Christophe) - Better struct packing (Christophe JAILLET) - Reduce controller error logs for optional commands (Keith) - Support for >=64KiB block sizes (Daniel Gomez) - Fabrics fixes and code organization (Max, Chaitanya, Daniel Wagner) - bcache updates via Coly: - Fix a race at init time (Mingzhe Zou) - Misc fixes and cleanups (Andrea, Thomas, Zheng, Ye) - use page pinning in the block layer for dio (David) - convert old block dio code to page pinning (David, Christoph) - cleanups for pktcdvd (Andy) - cleanups for rnbd (Guoqing) - use the unchecked __bio_add_page() for the initial single page additions (Johannes) - fix overflows in the Amiga partition handling code (Michael) - improve mq-deadline zoned device support (Bart) - keep passthrough requests out of the IO schedulers (Christoph, Ming) - improve support for flush requests, making them less special to deal with (Christoph) - add bdev holder ops and shutdown methods (Christoph) - fix the name_to_dev_t() situation and use cases (Christoph) - decouple the block open flags from fmode_t (Christoph) - ublk updates and cleanups, including adding user copy support (Ming) - BFQ sanity checking (Bart) - convert brd from radix to xarray (Pankaj) - constify various structures (Thomas, Ivan) - more fine grained persistent reservation ioctl capability checks (Jingbo) - misc fixes and cleanups (Arnd, Azeem, Demi, Ed, Hengqi, Hou, Jan, Jordy, Li, Min, Yu, Zhong, Waiman) * tag 'for-6.5/block-2023-06-23' of git://git.kernel.dk/linux: (266 commits) scsi/sg: don't grab scsi host module reference ext4: Fix warning in blkdev_put() block: don't return -EINVAL for not found names in devt_from_devname cdrom: Fix spectre-v1 gadget block: Improve kernel-doc headers blk-mq: don't insert passthrough request into sw queue bsg: make bsg_class a static const structure ublk: make ublk_chr_class a static const structure aoe: make aoe_class a static const structure block/rnbd: make all 'class' structures const block: fix the exclusive open mask in disk_scan_partitions block: add overflow checks for Amiga partition support block: change all __u32 annotations to __be32 in affs_hardblocks.h block: fix signed int overflow in Amiga partition support block: add capacity validation in bdev_add_partition() block: fine-granular CAP_SYS_ADMIN for Persistent Reservation block: disallow Persistent Reservation on partitions reiserfs: fix blkdev_put() warning from release_journal_dev() block: fix wrong mode for blkdev_get_by_dev() from disk_scan_partitions() block: document the holder argument to blkdev_get_by_path ...

block: convert bio_map_user_iov to use iov_iter_extract_pages

2023-05-24T14:42:44+00:00

This will pin pages or leave them unaltered rather than getting a ref on them as appropriate to the iterator. The pages need to be pinned for DIO rather than having refs taken on them to prevent VM copy-on-write from malfunctioning during a concurrent fork() (the result of the I/O could otherwise end up being visible to/affected by the child process). Signed-off-by: David Howells Reviewed-by: Christoph Hellwig Reviewed-by: John Hubbard cc: Al Viro cc: Jens Axboe cc: Jan Kara cc: Matthew Wilcox cc: Logan Gunthorpe cc: linux-block@vger.kernel.org Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20230522205744.2825689-7-dhowells@redhat.com Signed-off-by: Jens Axboe

block: Replace BIO_NO_PAGE_REF with BIO_PAGE_REFFED with inverted logic

2023-05-24T14:42:44+00:00

Replace BIO_NO_PAGE_REF with a BIO_PAGE_REFFED flag that has the inverted meaning is only set when a page reference has been acquired that needs to be released by bio_release_pages(). Signed-off-by: Christoph Hellwig Signed-off-by: David Howells Reviewed-by: John Hubbard cc: Al Viro cc: Jens Axboe cc: Jan Kara cc: Matthew Wilcox cc: Logan Gunthorpe cc: linux-block@vger.kernel.org Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20230522205744.2825689-4-dhowells@redhat.com Signed-off-by: Jens Axboe

block: fix bio-cache for passthru IO

2023-05-23T17:11:29+00:00

commit <8af870aa5b847> ("block: enable bio caching use for passthru IO") introduced bio-cache for passthru IO. In case when nr_vecs are greater than BIO_INLINE_VECS, bio and bvecs are allocated from mempool (instead of percpu cache) and REQ_ALLOC_CACHE is cleared. This causes the side effect of not freeing bio/bvecs into mempool on completion. This patch lets the passthru IO fallback to allocation using bio_kmalloc when nr_vecs are greater than BIO_INLINE_VECS. The corresponding bio is freed during call to blk_mq_map_bio_put during completion. Cc: stable@vger.kernel.org # 6.1 fixes <8af870aa5b847> ("block: enable bio caching use for passthru IO") Signed-off-by: Anuj Gupta Signed-off-by: Kanchan Joshi Link: https://lore.kernel.org/r/20230523111709.145676-1-anuj20.g@samsung.com Signed-off-by: Jens Axboe

iov_iter: add iter_iovec() helper

2023-03-30T14:12:29+00:00

This returns a pointer to the current iovec entry in the iterator. Only useful with ITER_IOVEC right now, but it prepares us to treat ITER_UBUF and ITER_IOVEC identically for the first segment. Rename struct iov_iter->iov to iov_iter->__iov to find any potentially troublesome spots, and also to prevent anyone from adding new code that accesses iter->iov directly. Signed-off-by: Jens Axboe

block: ensure bio_alloc_map_data() deals with ITER_UBUF correctly

2023-03-29T14:55:18+00:00

This helper blindly copies the iovec, even if we don't have one. Make this case a bit smarter by only doing so if we have an iovec array to copy. Signed-off-by: Jens Axboe

Merge tag '6.3-rc-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6

2023-02-23T01:12:44+00:00

Pull cifs client updates from Steve French: "The largest subset of this is from David Howells et al: making the cifs/smb3 driver pass iov_iters down to the lowest layers, directly to the network transport rather than passing lists of pages around, helping multiple areas: - Pin user pages, thereby fixing the race between concurrent DIO read and fork, where the pages containing the DIO read buffer may end up belonging to the child process and not the parent - with the result that the parent might not see the retrieved data. - cifs shouldn't take refs on pages extracted from non-user-backed iterators (eg. KVEC). With these changes, cifs will apply the appropriate cleanup. - Making it easier to transition to using folios in cifs rather than pages by dealing with them through BVEC and XARRAY iterators. - Allowing cifs to use the new splice function The remainder are: - fixes for stable, including various fixes for uninitialized memory, wrong length field causing mount issue to very old servers, important directory lease fixes and reconnect fixes - cleanups (unused code removal, change one element array usage, and a change form strtobool to kstrtobool, and Kconfig cleanups) - SMBDIRECT (RDMA) fixes including iov_iter integration and UAF fixes - reconnect fixes - multichannel fixes, including improving channel allocation (to least used channel) - remove the last use of lock_page_killable by moving to folio_lock_killable" * tag '6.3-rc-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6: (46 commits) update internal module version number for cifs.ko cifs: update ip_addr for ses only for primary chan setup cifs: use tcon allocation functions even for dummy tcon cifs: use the least loaded channel for sending requests cifs: DIO to/from KVEC-type iterators should now work cifs: Remove unused code cifs: Build the RDMA SGE list directly from an iterator cifs: Change the I/O paths to use an iterator rather than a page list cifs: Add a function to read into an iter from a socket cifs: Add some helper functions cifs: Add a function to Hash the contents of an iterator cifs: Add a function to build an RDMA SGE list from an iterator netfs: Add a function to extract an iterator into a scatterlist netfs: Add a function to extract a UBUF or IOVEC into a BVEC iterator cifs: Implement splice_read to pass down ITER_BVEC not ITER_PIPE splice: Export filemap/direct_splice_read() iov_iter: Add a function to extract a page list from an iterator iov_iter: Define flags to qualify page extraction. splice: Add a func to do a splice from an O_DIRECT file without ITER_PIPE splice: Add a func to do a splice from a buffered file without ITER_PIPE ...