kernel/linux.git/fs/direct-io.c, branch linux-6.0.y

iov_iter: advancing variants of iov_iter_get_pages{,_alloc}()

2022-08-09T02:37:22+00:00

Most of the users immediately follow successful iov_iter_get_pages() with advancing by the amount it had returned. Provide inline wrappers doing that, convert trivial open-coded uses of those. BTW, iov_iter_get_pages() never returns more than it had been asked to; such checks in cifs ought to be removed someday... Reviewed-by: Jeff Layton Signed-off-by: Al Viro

new iov_iter flavour - ITER_UBUF

2022-08-09T02:37:15+00:00

Equivalent of single-segment iovec. Initialized by iov_iter_ubuf(), checked for by iter_is_ubuf(), otherwise behaves like ITER_IOVEC ones. We are going to expose the things like ->write_iter() et.al. to those in subsequent commits. New predicate (user_backed_iter()) that is true for ITER_IOVEC and ITER_UBUF; places like direct-IO handling should use that for checking that pages we modify after getting them from iov_iter_get_pages() would need to be dirtied. DO NOT assume that replacing iter_is_iovec() with user_backed_iter() will solve all problems - there's code that uses iter_is_iovec() to decide how to poke around in iov_iter guts and for that the predicate replacement obviously won't suffice. Signed-off-by: Al Viro

Merge tag 'pull-work.iov_iter-base' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2022-08-03T20:50:22+00:00

Pull vfs iov_iter updates from Al Viro: "Part 1 - isolated cleanups and optimizations. One of the goals is to reduce the overhead of using ->read_iter() and ->write_iter() instead of ->read()/->write(). new_sync_{read,write}() has a surprising amount of overhead, in particular inside iocb_flags(). That's the explanation for the beginning of the series is in this pile; it's not directly iov_iter-related, but it's a part of the same work..." * tag 'pull-work.iov_iter-base' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: first_iovec_segment(): just return address iov_iter: massage calling conventions for first_{iovec,bvec}_segment() iov_iter: first_{iovec,bvec}_segment() - simplify a bit iov_iter: lift dealing with maxpages out of first_{iovec,bvec}_segment() iov_iter_get_pages{,_alloc}(): cap the maxsize with MAX_RW_COUNT iov_iter_bvec_advance(): don't bother with bvec_iter copy_page_{to,from}_iter(): switch iovec variants to generic keep iocb_flags() result cached in struct file iocb: delay evaluation of IS_SYNC(...) until we want to check IOCB_DSYNC struct file: use anonymous union member for rcuhead and llist btrfs: use IOMAP_DIO_NOSYNC teach iomap_dio_rw() to suppress dsync No need of likely/unlikely on calls of check_copy_size()

fs/direct-io: Reduce the size of struct dio

2022-07-14T18:14:32+00:00

Reduce the size of struct dio by combining the 'op' and 'op_flags' into the new 'opf' member. Use the new blk_opf_t type to improve static type checking. This patch does not change any functionality. Reviewed-by: Jan Kara Cc: Al Viro Cc: Christoph Hellwig Cc: Darrick J. Wong Signed-off-by: Bart Van Assche Link: https://lore.kernel.org/r/20220714180729.1065367-49-bvanassche@acm.org Signed-off-by: Jens Axboe

iocb: delay evaluation of IS_SYNC(...) until we want to check IOCB_DSYNC

2022-06-10T20:05:15+00:00

New helper to be used instead of direct checks for IOCB_DSYNC: iocb_is_dsync(iocb). Checks converted, which allows to avoid the IS_SYNC(iocb->ki_filp->f_mapping->host) part (4 cache lines) from iocb_flags() - it's checked in iocb_is_dsync() instead Reviewed-by: Christian Brauner (Microsoft) Signed-off-by: Al Viro

direct-io: remove random prefetches

2022-04-18T01:50:02+00:00

Randomly poking into block device internals for manual prefetches isn't exactly a very maintainable thing to do. And none of the performance critical direct I/O implementations still use this library function anyway, so just drop it. Signed-off-by: Christoph Hellwig Reviewed-by: Damien Le Moal Link: https://lore.kernel.org/r/20220415045258.199825-28-hch@lst.de Signed-off-by: Jens Axboe

block: remove the per-bio/request write hint

2022-03-07T19:45:57+00:00

With the NVMe support for this gone, there are no consumers of these hints left, so remove them. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20220304175556.407719-2-hch@lst.de Signed-off-by: Jens Axboe

block: pass a block_device and opf to bio_alloc

2022-02-02T14:49:59+00:00

Pass the block_device and operation that we plan to use this bio for to bio_alloc to optimize the assignment. NULL/0 can be passed, both for the passthrough case on a raw request_queue and to temporarily avoid refactoring some nasty code. Also move the gfp_mask argument after the nr_vecs argument for a much more logical calling convention matching what most of the kernel does. Signed-off-by: Christoph Hellwig Reviewed-by: Chaitanya Kulkarni Link: https://lore.kernel.org/r/20220124091107.642561-18-hch@lst.de Signed-off-by: Jens Axboe

fs: get rid of the res2 iocb->ki_complete argument

2021-10-25T16:36:24+00:00

The second argument was only used by the USB gadget code, yet everyone pays the overhead of passing a zero to be passed into aio, where it ends up being part of the aio res2 value. Now that everybody is passing in zero, kill off the extra argument. Reviewed-by: Darrick J. Wong Signed-off-by: Jens Axboe

direct-io: remove blk_poll support

2021-10-18T12:17:35+00:00

The polling support in the legacy direct-io support is a little crufty. It already doesn't support the asynchronous polling needed for io_uring polling, and is hard to adopt to upcoming changes in the polling interfaces. Given that all the major file systems already use the iomap direct I/O code, just drop the polling support. Signed-off-by: Christoph Hellwig Tested-by: Mark Wunderlich Link: https://lore.kernel.org/r/20211012111226.760968-2-hch@lst.de Signed-off-by: Jens Axboe