From dc50eab76b709d68175a358d6e23a5a3890764d3 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 18 May 2024 19:39:57 +0200 Subject: Merging upstream version 6.7.7. Signed-off-by: Daniel Baumann --- fs/bcachefs/fs-io-direct.c | 677 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 677 insertions(+) create mode 100644 fs/bcachefs/fs-io-direct.c (limited to 'fs/bcachefs/fs-io-direct.c') diff --git a/fs/bcachefs/fs-io-direct.c b/fs/bcachefs/fs-io-direct.c new file mode 100644 index 0000000000..84e20c3ada --- /dev/null +++ b/fs/bcachefs/fs-io-direct.c @@ -0,0 +1,677 @@ +// SPDX-License-Identifier: GPL-2.0 +#ifndef NO_BCACHEFS_FS + +#include "bcachefs.h" +#include "alloc_foreground.h" +#include "fs.h" +#include "fs-io.h" +#include "fs-io-direct.h" +#include "fs-io-pagecache.h" +#include "io_read.h" +#include "io_write.h" + +#include +#include +#include +#include + +/* O_DIRECT reads */ + +struct dio_read { + struct closure cl; + struct kiocb *req; + long ret; + bool should_dirty; + struct bch_read_bio rbio; +}; + +static void bio_check_or_release(struct bio *bio, bool check_dirty) +{ + if (check_dirty) { + bio_check_pages_dirty(bio); + } else { + bio_release_pages(bio, false); + bio_put(bio); + } +} + +static CLOSURE_CALLBACK(bch2_dio_read_complete) +{ + closure_type(dio, struct dio_read, cl); + + dio->req->ki_complete(dio->req, dio->ret); + bio_check_or_release(&dio->rbio.bio, dio->should_dirty); +} + +static void bch2_direct_IO_read_endio(struct bio *bio) +{ + struct dio_read *dio = bio->bi_private; + + if (bio->bi_status) + dio->ret = blk_status_to_errno(bio->bi_status); + + closure_put(&dio->cl); +} + +static void bch2_direct_IO_read_split_endio(struct bio *bio) +{ + struct dio_read *dio = bio->bi_private; + bool should_dirty = dio->should_dirty; + + bch2_direct_IO_read_endio(bio); + bio_check_or_release(bio, should_dirty); +} + +static int bch2_direct_IO_read(struct kiocb *req, struct iov_iter *iter) +{ + struct file *file = req->ki_filp; + struct bch_inode_info *inode = file_bch_inode(file); + struct bch_fs *c = inode->v.i_sb->s_fs_info; + struct bch_io_opts opts; + struct dio_read *dio; + struct bio *bio; + loff_t offset = req->ki_pos; + bool sync = is_sync_kiocb(req); + size_t shorten; + ssize_t ret; + + bch2_inode_opts_get(&opts, c, &inode->ei_inode); + + if ((offset|iter->count) & (block_bytes(c) - 1)) + return -EINVAL; + + ret = min_t(loff_t, iter->count, + max_t(loff_t, 0, i_size_read(&inode->v) - offset)); + + if (!ret) + return ret; + + shorten = iov_iter_count(iter) - round_up(ret, block_bytes(c)); + iter->count -= shorten; + + bio = bio_alloc_bioset(NULL, + bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS), + REQ_OP_READ, + GFP_KERNEL, + &c->dio_read_bioset); + + bio->bi_end_io = bch2_direct_IO_read_endio; + + dio = container_of(bio, struct dio_read, rbio.bio); + closure_init(&dio->cl, NULL); + + /* + * this is a _really_ horrible hack just to avoid an atomic sub at the + * end: + */ + if (!sync) { + set_closure_fn(&dio->cl, bch2_dio_read_complete, NULL); + atomic_set(&dio->cl.remaining, + CLOSURE_REMAINING_INITIALIZER - + CLOSURE_RUNNING + + CLOSURE_DESTRUCTOR); + } else { + atomic_set(&dio->cl.remaining, + CLOSURE_REMAINING_INITIALIZER + 1); + dio->cl.closure_get_happened = true; + } + + dio->req = req; + dio->ret = ret; + /* + * This is one of the sketchier things I've encountered: we have to skip + * the dirtying of requests that are internal from the kernel (i.e. from + * loopback), because we'll deadlock on page_lock. + */ + dio->should_dirty = iter_is_iovec(iter); + + goto start; + while (iter->count) { + bio = bio_alloc_bioset(NULL, + bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS), + REQ_OP_READ, + GFP_KERNEL, + &c->bio_read); + bio->bi_end_io = bch2_direct_IO_read_split_endio; +start: + bio->bi_opf = REQ_OP_READ|REQ_SYNC; + bio->bi_iter.bi_sector = offset >> 9; + bio->bi_private = dio; + + ret = bio_iov_iter_get_pages(bio, iter); + if (ret < 0) { + /* XXX: fault inject this path */ + bio->bi_status = BLK_STS_RESOURCE; + bio_endio(bio); + break; + } + + offset += bio->bi_iter.bi_size; + + if (dio->should_dirty) + bio_set_pages_dirty(bio); + + if (iter->count) + closure_get(&dio->cl); + + bch2_read(c, rbio_init(bio, opts), inode_inum(inode)); + } + + iter->count += shorten; + + if (sync) { + closure_sync(&dio->cl); + closure_debug_destroy(&dio->cl); + ret = dio->ret; + bio_check_or_release(&dio->rbio.bio, dio->should_dirty); + return ret; + } else { + return -EIOCBQUEUED; + } +} + +ssize_t bch2_read_iter(struct kiocb *iocb, struct iov_iter *iter) +{ + struct file *file = iocb->ki_filp; + struct bch_inode_info *inode = file_bch_inode(file); + struct address_space *mapping = file->f_mapping; + size_t count = iov_iter_count(iter); + ssize_t ret; + + if (!count) + return 0; /* skip atime */ + + if (iocb->ki_flags & IOCB_DIRECT) { + struct blk_plug plug; + + if (unlikely(mapping->nrpages)) { + ret = filemap_write_and_wait_range(mapping, + iocb->ki_pos, + iocb->ki_pos + count - 1); + if (ret < 0) + goto out; + } + + file_accessed(file); + + blk_start_plug(&plug); + ret = bch2_direct_IO_read(iocb, iter); + blk_finish_plug(&plug); + + if (ret >= 0) + iocb->ki_pos += ret; + } else { + bch2_pagecache_add_get(inode); + ret = generic_file_read_iter(iocb, iter); + bch2_pagecache_add_put(inode); + } +out: + return bch2_err_class(ret); +} + +/* O_DIRECT writes */ + +struct dio_write { + struct kiocb *req; + struct address_space *mapping; + struct bch_inode_info *inode; + struct mm_struct *mm; + const struct iovec *iov; + unsigned loop:1, + extending:1, + sync:1, + flush:1; + struct quota_res quota_res; + u64 written; + + struct iov_iter iter; + struct iovec inline_vecs[2]; + + /* must be last: */ + struct bch_write_op op; +}; + +static bool bch2_check_range_allocated(struct bch_fs *c, subvol_inum inum, + u64 offset, u64 size, + unsigned nr_replicas, bool compressed) +{ + struct btree_trans *trans = bch2_trans_get(c); + struct btree_iter iter; + struct bkey_s_c k; + u64 end = offset + size; + u32 snapshot; + bool ret = true; + int err; +retry: + bch2_trans_begin(trans); + + err = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot); + if (err) + goto err; + + for_each_btree_key_norestart(trans, iter, BTREE_ID_extents, + SPOS(inum.inum, offset, snapshot), + BTREE_ITER_SLOTS, k, err) { + if (bkey_ge(bkey_start_pos(k.k), POS(inum.inum, end))) + break; + + if (k.k->p.snapshot != snapshot || + nr_replicas > bch2_bkey_replicas(c, k) || + (!compressed && bch2_bkey_sectors_compressed(k))) { + ret = false; + break; + } + } + + offset = iter.pos.offset; + bch2_trans_iter_exit(trans, &iter); +err: + if (bch2_err_matches(err, BCH_ERR_transaction_restart)) + goto retry; + bch2_trans_put(trans); + + return err ? false : ret; +} + +static noinline bool bch2_dio_write_check_allocated(struct dio_write *dio) +{ + struct bch_fs *c = dio->op.c; + struct bch_inode_info *inode = dio->inode; + struct bio *bio = &dio->op.wbio.bio; + + return bch2_check_range_allocated(c, inode_inum(inode), + dio->op.pos.offset, bio_sectors(bio), + dio->op.opts.data_replicas, + dio->op.opts.compression != 0); +} + +static void bch2_dio_write_loop_async(struct bch_write_op *); +static __always_inline long bch2_dio_write_done(struct dio_write *dio); + +/* + * We're going to return -EIOCBQUEUED, but we haven't finished consuming the + * iov_iter yet, so we need to stash a copy of the iovec: it might be on the + * caller's stack, we're not guaranteed that it will live for the duration of + * the IO: + */ +static noinline int bch2_dio_write_copy_iov(struct dio_write *dio) +{ + struct iovec *iov = dio->inline_vecs; + + /* + * iov_iter has a single embedded iovec - nothing to do: + */ + if (iter_is_ubuf(&dio->iter)) + return 0; + + /* + * We don't currently handle non-iovec iov_iters here - return an error, + * and we'll fall back to doing the IO synchronously: + */ + if (!iter_is_iovec(&dio->iter)) + return -1; + + if (dio->iter.nr_segs > ARRAY_SIZE(dio->inline_vecs)) { + dio->iov = iov = kmalloc_array(dio->iter.nr_segs, sizeof(*iov), + GFP_KERNEL); + if (unlikely(!iov)) + return -ENOMEM; + } + + memcpy(iov, dio->iter.__iov, dio->iter.nr_segs * sizeof(*iov)); + dio->iter.__iov = iov; + return 0; +} + +static CLOSURE_CALLBACK(bch2_dio_write_flush_done) +{ + closure_type(dio, struct dio_write, op.cl); + struct bch_fs *c = dio->op.c; + + closure_debug_destroy(cl); + + dio->op.error = bch2_journal_error(&c->journal); + + bch2_dio_write_done(dio); +} + +static noinline void bch2_dio_write_flush(struct dio_write *dio) +{ + struct bch_fs *c = dio->op.c; + struct bch_inode_unpacked inode; + int ret; + + dio->flush = 0; + + closure_init(&dio->op.cl, NULL); + + if (!dio->op.error) { + ret = bch2_inode_find_by_inum(c, inode_inum(dio->inode), &inode); + if (ret) { + dio->op.error = ret; + } else { + bch2_journal_flush_seq_async(&c->journal, inode.bi_journal_seq, + &dio->op.cl); + bch2_inode_flush_nocow_writes_async(c, dio->inode, &dio->op.cl); + } + } + + if (dio->sync) { + closure_sync(&dio->op.cl); + closure_debug_destroy(&dio->op.cl); + } else { + continue_at(&dio->op.cl, bch2_dio_write_flush_done, NULL); + } +} + +static __always_inline long bch2_dio_write_done(struct dio_write *dio) +{ + struct kiocb *req = dio->req; + struct bch_inode_info *inode = dio->inode; + bool sync = dio->sync; + long ret; + + if (unlikely(dio->flush)) { + bch2_dio_write_flush(dio); + if (!sync) + return -EIOCBQUEUED; + } + + bch2_pagecache_block_put(inode); + + kfree(dio->iov); + + ret = dio->op.error ?: ((long) dio->written << 9); + bio_put(&dio->op.wbio.bio); + + /* inode->i_dio_count is our ref on inode and thus bch_fs */ + inode_dio_end(&inode->v); + + if (ret < 0) + ret = bch2_err_class(ret); + + if (!sync) { + req->ki_complete(req, ret); + ret = -EIOCBQUEUED; + } + return ret; +} + +static __always_inline void bch2_dio_write_end(struct dio_write *dio) +{ + struct bch_fs *c = dio->op.c; + struct kiocb *req = dio->req; + struct bch_inode_info *inode = dio->inode; + struct bio *bio = &dio->op.wbio.bio; + + req->ki_pos += (u64) dio->op.written << 9; + dio->written += dio->op.written; + + if (dio->extending) { + spin_lock(&inode->v.i_lock); + if (req->ki_pos > inode->v.i_size) + i_size_write(&inode->v, req->ki_pos); + spin_unlock(&inode->v.i_lock); + } + + if (dio->op.i_sectors_delta || dio->quota_res.sectors) { + mutex_lock(&inode->ei_quota_lock); + __bch2_i_sectors_acct(c, inode, &dio->quota_res, dio->op.i_sectors_delta); + __bch2_quota_reservation_put(c, inode, &dio->quota_res); + mutex_unlock(&inode->ei_quota_lock); + } + + bio_release_pages(bio, false); + + if (unlikely(dio->op.error)) + set_bit(EI_INODE_ERROR, &inode->ei_flags); +} + +static __always_inline long bch2_dio_write_loop(struct dio_write *dio) +{ + struct bch_fs *c = dio->op.c; + struct kiocb *req = dio->req; + struct address_space *mapping = dio->mapping; + struct bch_inode_info *inode = dio->inode; + struct bch_io_opts opts; + struct bio *bio = &dio->op.wbio.bio; + unsigned unaligned, iter_count; + bool sync = dio->sync, dropped_locks; + long ret; + + bch2_inode_opts_get(&opts, c, &inode->ei_inode); + + while (1) { + iter_count = dio->iter.count; + + EBUG_ON(current->faults_disabled_mapping); + current->faults_disabled_mapping = mapping; + + ret = bio_iov_iter_get_pages(bio, &dio->iter); + + dropped_locks = fdm_dropped_locks(); + + current->faults_disabled_mapping = NULL; + + /* + * If the fault handler returned an error but also signalled + * that it dropped & retook ei_pagecache_lock, we just need to + * re-shoot down the page cache and retry: + */ + if (dropped_locks && ret) + ret = 0; + + if (unlikely(ret < 0)) + goto err; + + if (unlikely(dropped_locks)) { + ret = bch2_write_invalidate_inode_pages_range(mapping, + req->ki_pos, + req->ki_pos + iter_count - 1); + if (unlikely(ret)) + goto err; + + if (!bio->bi_iter.bi_size) + continue; + } + + unaligned = bio->bi_iter.bi_size & (block_bytes(c) - 1); + bio->bi_iter.bi_size -= unaligned; + iov_iter_revert(&dio->iter, unaligned); + + if (!bio->bi_iter.bi_size) { + /* + * bio_iov_iter_get_pages was only able to get < + * blocksize worth of pages: + */ + ret = -EFAULT; + goto err; + } + + bch2_write_op_init(&dio->op, c, opts); + dio->op.end_io = sync + ? NULL + : bch2_dio_write_loop_async; + dio->op.target = dio->op.opts.foreground_target; + dio->op.write_point = writepoint_hashed((unsigned long) current); + dio->op.nr_replicas = dio->op.opts.data_replicas; + dio->op.subvol = inode->ei_subvol; + dio->op.pos = POS(inode->v.i_ino, (u64) req->ki_pos >> 9); + dio->op.devs_need_flush = &inode->ei_devs_need_flush; + + if (sync) + dio->op.flags |= BCH_WRITE_SYNC; + dio->op.flags |= BCH_WRITE_CHECK_ENOSPC; + + ret = bch2_quota_reservation_add(c, inode, &dio->quota_res, + bio_sectors(bio), true); + if (unlikely(ret)) + goto err; + + ret = bch2_disk_reservation_get(c, &dio->op.res, bio_sectors(bio), + dio->op.opts.data_replicas, 0); + if (unlikely(ret) && + !bch2_dio_write_check_allocated(dio)) + goto err; + + task_io_account_write(bio->bi_iter.bi_size); + + if (unlikely(dio->iter.count) && + !dio->sync && + !dio->loop && + bch2_dio_write_copy_iov(dio)) + dio->sync = sync = true; + + dio->loop = true; + closure_call(&dio->op.cl, bch2_write, NULL, NULL); + + if (!sync) + return -EIOCBQUEUED; + + bch2_dio_write_end(dio); + + if (likely(!dio->iter.count) || dio->op.error) + break; + + bio_reset(bio, NULL, REQ_OP_WRITE); + } +out: + return bch2_dio_write_done(dio); +err: + dio->op.error = ret; + + bio_release_pages(bio, false); + + bch2_quota_reservation_put(c, inode, &dio->quota_res); + goto out; +} + +static noinline __cold void bch2_dio_write_continue(struct dio_write *dio) +{ + struct mm_struct *mm = dio->mm; + + bio_reset(&dio->op.wbio.bio, NULL, REQ_OP_WRITE); + + if (mm) + kthread_use_mm(mm); + bch2_dio_write_loop(dio); + if (mm) + kthread_unuse_mm(mm); +} + +static void bch2_dio_write_loop_async(struct bch_write_op *op) +{ + struct dio_write *dio = container_of(op, struct dio_write, op); + + bch2_dio_write_end(dio); + + if (likely(!dio->iter.count) || dio->op.error) + bch2_dio_write_done(dio); + else + bch2_dio_write_continue(dio); +} + +ssize_t bch2_direct_write(struct kiocb *req, struct iov_iter *iter) +{ + struct file *file = req->ki_filp; + struct address_space *mapping = file->f_mapping; + struct bch_inode_info *inode = file_bch_inode(file); + struct bch_fs *c = inode->v.i_sb->s_fs_info; + struct dio_write *dio; + struct bio *bio; + bool locked = true, extending; + ssize_t ret; + + prefetch(&c->opts); + prefetch((void *) &c->opts + 64); + prefetch(&inode->ei_inode); + prefetch((void *) &inode->ei_inode + 64); + + inode_lock(&inode->v); + + ret = generic_write_checks(req, iter); + if (unlikely(ret <= 0)) + goto err; + + ret = file_remove_privs(file); + if (unlikely(ret)) + goto err; + + ret = file_update_time(file); + if (unlikely(ret)) + goto err; + + if (unlikely((req->ki_pos|iter->count) & (block_bytes(c) - 1))) + goto err; + + inode_dio_begin(&inode->v); + bch2_pagecache_block_get(inode); + + extending = req->ki_pos + iter->count > inode->v.i_size; + if (!extending) { + inode_unlock(&inode->v); + locked = false; + } + + bio = bio_alloc_bioset(NULL, + bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS), + REQ_OP_WRITE, + GFP_KERNEL, + &c->dio_write_bioset); + dio = container_of(bio, struct dio_write, op.wbio.bio); + dio->req = req; + dio->mapping = mapping; + dio->inode = inode; + dio->mm = current->mm; + dio->iov = NULL; + dio->loop = false; + dio->extending = extending; + dio->sync = is_sync_kiocb(req) || extending; + dio->flush = iocb_is_dsync(req) && !c->opts.journal_flush_disabled; + dio->quota_res.sectors = 0; + dio->written = 0; + dio->iter = *iter; + dio->op.c = c; + + if (unlikely(mapping->nrpages)) { + ret = bch2_write_invalidate_inode_pages_range(mapping, + req->ki_pos, + req->ki_pos + iter->count - 1); + if (unlikely(ret)) + goto err_put_bio; + } + + ret = bch2_dio_write_loop(dio); +err: + if (locked) + inode_unlock(&inode->v); + return ret; +err_put_bio: + bch2_pagecache_block_put(inode); + bio_put(bio); + inode_dio_end(&inode->v); + goto err; +} + +void bch2_fs_fs_io_direct_exit(struct bch_fs *c) +{ + bioset_exit(&c->dio_write_bioset); + bioset_exit(&c->dio_read_bioset); +} + +int bch2_fs_fs_io_direct_init(struct bch_fs *c) +{ + if (bioset_init(&c->dio_read_bioset, + 4, offsetof(struct dio_read, rbio.bio), + BIOSET_NEED_BVECS)) + return -BCH_ERR_ENOMEM_dio_read_bioset_init; + + if (bioset_init(&c->dio_write_bioset, + 4, offsetof(struct dio_write, op.wbio.bio), + BIOSET_NEED_BVECS)) + return -BCH_ERR_ENOMEM_dio_write_bioset_init; + + return 0; +} + +#endif /* NO_BCACHEFS_FS */ -- cgit v1.2.3