diff options
Diffstat (limited to 'fs/bcachefs/fs-io.c')
| -rw-r--r-- | fs/bcachefs/fs-io.c | 2862 |
1 files changed, 2862 insertions, 0 deletions
diff --git a/fs/bcachefs/fs-io.c b/fs/bcachefs/fs-io.c new file mode 100644 index 000000000000..56d21175058c --- /dev/null +++ b/fs/bcachefs/fs-io.c @@ -0,0 +1,2862 @@ +// SPDX-License-Identifier: GPL-2.0 +#ifndef NO_BCACHEFS_FS + +#include "bcachefs.h" +#include "btree_update.h" +#include "buckets.h" +#include "clock.h" +#include "error.h" +#include "fs.h" +#include "fs-io.h" +#include "fsck.h" +#include "inode.h" +#include "journal.h" +#include "io.h" +#include "keylist.h" +#include "quota.h" +#include "trace.h" + +#include <linux/aio.h> +#include <linux/backing-dev.h> +#include <linux/falloc.h> +#include <linux/migrate.h> +#include <linux/mmu_context.h> +#include <linux/pagevec.h> +#include <linux/sched/signal.h> +#include <linux/task_io_accounting_ops.h> +#include <linux/uio.h> +#include <linux/writeback.h> + +#include <trace/events/writeback.h> + +struct quota_res { + u64 sectors; +}; + +struct i_sectors_hook { + struct extent_insert_hook hook; + struct bch_inode_info *inode; + struct quota_res quota_res; + s64 sectors; + u64 new_i_size; + unsigned flags; + unsigned appending:1; +}; + +struct bchfs_write_op { + struct bch_inode_info *inode; + s64 sectors_added; + bool is_dio; + bool unalloc; + u64 new_i_size; + + /* must be last: */ + struct bch_write_op op; +}; + +struct bch_writepage_io { + struct closure cl; + u64 new_sectors; + + /* must be last: */ + struct bchfs_write_op op; +}; + +struct dio_write { + struct closure cl; + struct kiocb *req; + struct task_struct *task; + unsigned loop:1, + sync:1, + free_iov:1; + struct quota_res quota_res; + + struct iov_iter iter; + struct iovec inline_vecs[2]; + + /* must be last: */ + struct bchfs_write_op iop; +}; + +struct dio_read { + struct closure cl; + struct kiocb *req; + long ret; + struct bch_read_bio rbio; +}; + +/* pagecache_block must be held */ +static int write_invalidate_inode_pages_range(struct address_space *mapping, + loff_t start, loff_t end) +{ + int ret; + + /* + * XXX: the way this is currently implemented, we can spin if a process + * is continually redirtying a specific page + */ + do { + if (!mapping->nrpages) + return 0; + + ret = filemap_write_and_wait_range(mapping, start, end); + if (ret) + break; + + if (!mapping->nrpages) + return 0; + + ret = invalidate_inode_pages2_range(mapping, + start >> PAGE_SHIFT, + end >> PAGE_SHIFT); + } while (ret == -EBUSY); + + return ret; +} + +/* quotas */ + +#ifdef CONFIG_BCACHEFS_QUOTA + +static void bch2_quota_reservation_put(struct bch_fs *c, + struct bch_inode_info *inode, + struct quota_res *res) +{ + if (!res->sectors) + return; + + mutex_lock(&inode->ei_quota_lock); + BUG_ON(res->sectors > inode->ei_quota_reserved); + + bch2_quota_acct(c, inode->ei_qid, Q_SPC, + -((s64) res->sectors), BCH_QUOTA_PREALLOC); + inode->ei_quota_reserved -= res->sectors; + mutex_unlock(&inode->ei_quota_lock); + + res->sectors = 0; +} + +static int bch2_quota_reservation_add(struct bch_fs *c, + struct bch_inode_info *inode, + struct quota_res *res, + unsigned sectors, + bool check_enospc) +{ + int ret; + + mutex_lock(&inode->ei_quota_lock); + ret = bch2_quota_acct(c, inode->ei_qid, Q_SPC, sectors, + check_enospc ? BCH_QUOTA_PREALLOC : BCH_QUOTA_NOCHECK); + if (likely(!ret)) { + inode->ei_quota_reserved += sectors; + res->sectors += sectors; + } + mutex_unlock(&inode->ei_quota_lock); + + return ret; +} + +#else + +static void bch2_quota_reservation_put(struct bch_fs *c, + struct bch_inode_info *inode, + struct quota_res *res) +{ +} + +static int bch2_quota_reservation_add(struct bch_fs *c, + struct bch_inode_info *inode, + struct quota_res *res, + unsigned sectors, + bool check_enospc) +{ + return 0; +} + +#endif + +/* i_size updates: */ + +static int inode_set_size(struct bch_inode_info *inode, + struct bch_inode_unpacked *bi, + void *p) +{ + loff_t *new_i_size = p; + + lockdep_assert_held(&inode->ei_update_lock); + + bi->bi_size = *new_i_size; + return 0; +} + +static int __must_check bch2_write_inode_size(struct bch_fs *c, + struct bch_inode_info *inode, + loff_t new_size) +{ + return __bch2_write_inode(c, inode, inode_set_size, &new_size, 0); +} + +static void i_sectors_acct(struct bch_fs *c, struct bch_inode_info *inode, + struct quota_res *quota_res, int sectors) +{ + mutex_lock(&inode->ei_quota_lock); +#ifdef CONFIG_BCACHEFS_QUOTA + if (quota_res && sectors > 0) { + BUG_ON(sectors > quota_res->sectors); + BUG_ON(sectors > inode->ei_quota_reserved); + + quota_res->sectors -= sectors; + inode->ei_quota_reserved -= sectors; + } else { + bch2_quota_acct(c, inode->ei_qid, Q_SPC, sectors, BCH_QUOTA_WARN); + } +#endif + inode->v.i_blocks += sectors; + mutex_unlock(&inode->ei_quota_lock); +} + +/* i_sectors accounting: */ + +static enum btree_insert_ret +i_sectors_hook_fn(struct extent_insert_hook *hook, + struct bpos committed_pos, + struct bpos next_pos, + struct bkey_s_c k, + const struct bkey_i *insert) +{ + struct i_sectors_hook *h = container_of(hook, + struct i_sectors_hook, hook); + s64 sectors = next_pos.offset - committed_pos.offset; + int sign = bkey_extent_is_allocation(&insert->k) - + (k.k && bkey_extent_is_allocation(k.k)); + + EBUG_ON(!(h->inode->ei_inode.bi_flags & BCH_INODE_I_SECTORS_DIRTY)); + + h->sectors += sectors * sign; + + return BTREE_INSERT_OK; +} + +static int i_sectors_dirty_finish_fn(struct bch_inode_info *inode, + struct bch_inode_unpacked *bi, + void *p) +{ + struct i_sectors_hook *h = p; + + if (h->new_i_size != U64_MAX && + (!h->appending || + h->new_i_size > bi->bi_size)) + bi->bi_size = h->new_i_size; + bi->bi_sectors += h->sectors; + bi->bi_flags &= ~h->flags; + return 0; +} + +static int i_sectors_dirty_finish(struct bch_fs *c, struct i_sectors_hook *h) +{ + int ret; + + mutex_lock(&h->inode->ei_update_lock); + i_sectors_acct(c, h->inode, &h->quota_res, h->sectors); + + ret = __bch2_write_inode(c, h->inode, i_sectors_dirty_finish_fn, h, 0); + + if (!ret && h->new_i_size != U64_MAX) + i_size_write(&h->inode->v, h->new_i_size); + mutex_unlock(&h->inode->ei_update_lock); + + bch2_quota_reservation_put(c, h->inode, &h->quota_res); + + h->sectors = 0; + + return ret; +} + +static int i_sectors_dirty_start_fn(struct bch_inode_info *inode, + struct bch_inode_unpacked *bi, void *p) +{ + struct i_sectors_hook *h = p; + + if (h->flags & BCH_INODE_I_SIZE_DIRTY) + bi->bi_size = h->new_i_size; + + bi->bi_flags |= h->flags; + return 0; +} + +static int i_sectors_dirty_start(struct bch_fs *c, struct i_sectors_hook *h) +{ + int ret; + + mutex_lock(&h->inode->ei_update_lock); + ret = __bch2_write_inode(c, h->inode, i_sectors_dirty_start_fn, h, 0); + mutex_unlock(&h->inode->ei_update_lock); + + return ret; +} + +static inline struct i_sectors_hook +i_sectors_hook_init(struct bch_inode_info *inode, unsigned flags) +{ + return (struct i_sectors_hook) { + .hook.fn = i_sectors_hook_fn, + .inode = inode, + .sectors = 0, + .new_i_size = U64_MAX, + .flags = flags|BCH_INODE_I_SECTORS_DIRTY, + }; +} + +/* normal i_size/i_sectors update machinery: */ + +struct bchfs_extent_trans_hook { + struct bchfs_write_op *op; + struct extent_insert_hook hook; + + struct bch_inode_unpacked inode_u; + struct bkey_inode_buf inode_p; + + bool need_inode_update; +}; + +static enum btree_insert_ret +bchfs_extent_update_hook(struct extent_insert_hook *hook, + struct bpos committed_pos, + struct bpos next_pos, + struct bkey_s_c k, + const struct bkey_i *insert) +{ + struct bchfs_extent_trans_hook *h = container_of(hook, + struct bchfs_extent_trans_hook, hook); + struct bch_inode_info *inode = h->op->inode; + int sign = bkey_extent_is_allocation(&insert->k) - + (k.k && bkey_extent_is_allocation(k.k)); + s64 sectors = (s64) (next_pos.offset - committed_pos.offset) * sign; + u64 offset = min(next_pos.offset << 9, h->op->new_i_size); + bool do_pack = false; + + if (h->op->unalloc && + !bch2_extent_is_fully_allocated(k)) + return BTREE_INSERT_ENOSPC; + + BUG_ON((next_pos.offset << 9) > round_up(offset, PAGE_SIZE)); + + /* XXX: inode->i_size locking */ + if (offset > inode->ei_inode.bi_size) { + if (!h->need_inode_update) { + h->need_inode_update = true; + return BTREE_INSERT_NEED_TRAVERSE; + } + + /* truncate in progress? */ + if (h->inode_u.bi_flags & BCH_INODE_I_SIZE_DIRTY) + goto no_i_size_update; + + h->inode_u.bi_size = offset; + do_pack = true; + + inode->ei_inode.bi_size = offset; + + spin_lock(&inode->v.i_lock); + if (offset > inode->v.i_size) { + if (h->op->is_dio) + i_size_write(&inode->v, offset); + else + BUG(); + } + spin_unlock(&inode->v.i_lock); + } +no_i_size_update: + if (sectors) { + if (!h->need_inode_update) { + h->need_inode_update = true; + return BTREE_INSERT_NEED_TRAVERSE; + } + + h->inode_u.bi_sectors += sectors; + do_pack = true; + + h->op->sectors_added += sectors; + } + + if (do_pack) + bch2_inode_pack(&h->inode_p, &h->inode_u); + + return BTREE_INSERT_OK; +} + +static int bchfs_write_index_update(struct bch_write_op *wop) +{ + struct bchfs_write_op *op = container_of(wop, + struct bchfs_write_op, op); + struct keylist *keys = &op->op.insert_keys; + struct btree_iter extent_iter, inode_iter; + struct bchfs_extent_trans_hook hook; + struct bkey_i *k = bch2_keylist_front(keys); + s64 orig_sectors_added = op->sectors_added; + int ret; + + BUG_ON(k->k.p.inode != op->inode->v.i_ino); + + bch2_btree_iter_init(&extent_iter, wop->c, BTREE_ID_EXTENTS, + bkey_start_pos(&bch2_keylist_front(keys)->k), + BTREE_ITER_INTENT); + bch2_btree_iter_init(&inode_iter, wop->c, BTREE_ID_INODES, + POS(extent_iter.pos.inode, 0), + BTREE_ITER_SLOTS|BTREE_ITER_INTENT); + + hook.op = op; + hook.hook.fn = bchfs_extent_update_hook; + hook.need_inode_update = false; + + do { + /* XXX: inode->i_size locking */ + k = bch2_keylist_front(keys); + if (min(k->k.p.offset << 9, op->new_i_size) > + op->inode->ei_inode.bi_size) + hook.need_inode_update = true; + + /* optimization for fewer transaction restarts: */ + ret = bch2_btree_iter_traverse(&extent_iter); + if (ret) + goto err; + + if (hook.need_inode_update) { + struct bkey_s_c inode; + + if (!btree_iter_linked(&inode_iter)) + bch2_btree_iter_link(&extent_iter, &inode_iter); + + inode = bch2_btree_iter_peek_slot(&inode_iter); + if ((ret = btree_iter_err(inode))) + goto err; + + if (WARN_ONCE(inode.k->type != BCH_INODE_FS, + "inode %llu not found when updating", + extent_iter.pos.inode)) { + ret = -ENOENT; + break; + } + + if (WARN_ONCE(bkey_bytes(inode.k) > + sizeof(hook.inode_p), + "inode %llu too big (%zu bytes, buf %zu)", + extent_iter.pos.inode, + bkey_bytes(inode.k), + sizeof(hook.inode_p))) { + ret = -ENOENT; + break; + } + + bkey_reassemble(&hook.inode_p.inode.k_i, inode); + ret = bch2_inode_unpack(bkey_s_c_to_inode(inode), + &hook.inode_u); + if (WARN_ONCE(ret, + "error %i unpacking inode %llu", + ret, extent_iter.pos.inode)) { + ret = -ENOENT; + break; + } + + ret = bch2_btree_insert_at(wop->c, &wop->res, + &hook.hook, op_journal_seq(wop), + BTREE_INSERT_NOFAIL| + BTREE_INSERT_ATOMIC| + BTREE_INSERT_USE_RESERVE, + BTREE_INSERT_ENTRY(&extent_iter, k), + BTREE_INSERT_ENTRY_EXTRA_RES(&inode_iter, + &hook.inode_p.inode.k_i, 2)); + } else { + ret = bch2_btree_insert_at(wop->c, &wop->res, + &hook.hook, op_journal_seq(wop), + BTREE_INSERT_NOFAIL| + BTREE_INSERT_ATOMIC| + BTREE_INSERT_USE_RESERVE, + BTREE_INSERT_ENTRY(&extent_iter, k)); + } + + BUG_ON(bkey_cmp(extent_iter.pos, bkey_start_pos(&k->k))); + + if (WARN_ONCE(!ret != !k->k.size, + "ret %i k->size %u", ret, k->k.size)) + ret = k->k.size ? -EINTR : 0; +err: + if (ret == -EINTR) + continue; + if (ret) + break; + + BUG_ON(bkey_cmp(extent_iter.pos, k->k.p) < 0); + bch2_keylist_pop_front(keys); + } while (!bch2_keylist_empty(keys)); + + bch2_btree_iter_unlock(&extent_iter); + bch2_btree_iter_unlock(&inode_iter); + + if (op->is_dio) { + struct dio_write *dio = container_of(op, struct dio_write, iop); + + i_sectors_acct(wop->c, op->inode, &dio->quota_res, + op->sectors_added - orig_sectors_added); + } + + return ret; +} + +static inline void bch2_fswrite_op_init(struct bchfs_write_op *op, + struct bch_fs *c, + struct bch_inode_info *inode, + struct bch_io_opts opts, + bool is_dio) +{ + op->inode = inode; + op->sectors_added = 0; + op->is_dio = is_dio; + op->unalloc = false; + op->new_i_size = U64_MAX; + + bch2_write_op_init(&op->op, c, opts); + op->op.target = opts.foreground_target; + op->op.index_update_fn = bchfs_write_index_update; + op_journal_seq_set(&op->op, &inode->ei_journal_seq); +} + +static inline struct bch_io_opts io_opts(struct bch_fs *c, struct bch_inode_info *inode) +{ + struct bch_io_opts opts = bch2_opts_to_inode_opts(c->opts); + + bch2_io_opts_apply(&opts, bch2_inode_opts_get(&inode->ei_inode)); + return opts; +} + +/* page state: */ + +/* stored in page->private: */ + +/* + * bch_page_state has to (unfortunately) be manipulated with cmpxchg - we could + * almost protected it with the page lock, except that bch2_writepage_io_done has + * to update the sector counts (and from interrupt/bottom half context). + */ +struct bch_page_state { +union { struct { + /* existing data: */ + unsigned sectors:PAGE_SECTOR_SHIFT + 1; + unsigned nr_replicas:4; + unsigned compressed:1; + + /* Owns PAGE_SECTORS sized reservation: */ + unsigned reserved:1; + unsigned reservation_replicas:4; + + /* Owns PAGE_SECTORS sized quota reservation: */ + unsigned quota_reserved:1; + + /* + * Number of sectors on disk - for i_blocks + * Uncompressed size, not compressed size: + */ + unsigned dirty_sectors:PAGE_SECTOR_SHIFT + 1; +}; + /* for cmpxchg: */ + unsigned long v; +}; +}; + +#define page_state_cmpxchg(_ptr, _new, _expr) \ +({ \ + unsigned long _v = READ_ONCE((_ptr)->v); \ + struct bch_page_state _old; \ + \ + do { \ + _old.v = _new.v = _v; \ + _expr; \ + \ + EBUG_ON(_new.sectors + _new.dirty_sectors > PAGE_SECTORS);\ + } while (_old.v != _new.v && \ + (_v = cmpxchg(&(_ptr)->v, _old.v, _new.v)) != _old.v); \ + \ + _old; \ +}) + +static inline struct bch_page_state *page_state(struct page *page) +{ + struct bch_page_state *s = (void *) &page->private; + + BUILD_BUG_ON(sizeof(*s) > sizeof(page->private)); + + if (!PagePrivate(page)) + SetPagePrivate(page); + + return s; +} + +static inline unsigned page_res_sectors(struct bch_page_state s) +{ + + return s.reserved ? s.reservation_replicas * PAGE_SECTORS : 0; +} + +static void __bch2_put_page_reservation(struct bch_fs *c, struct bch_inode_info *inode, + struct bch_page_state s) +{ + struct disk_reservation res = { .sectors = page_res_sectors(s) }; + struct quota_res quota_res = { .sectors = s.quota_reserved ? PAGE_SECTORS : 0 }; + + bch2_quota_reservation_put(c, inode, "a_res); + bch2_disk_reservation_put(c, &res); +} + +static void bch2_put_page_reservation(struct bch_fs *c, struct bch_inode_info *inode, + struct page *page) +{ + struct bch_page_state s; + + s = page_state_cmpxchg(page_state(page), s, { + s.reserved = 0; + s.quota_reserved = 0; + }); + + __bch2_put_page_reservation(c, inode, s); +} + +static int bch2_get_page_reservation(struct bch_fs *c, struct bch_inode_info *inode, + struct page *page, bool check_enospc) +{ + struct bch_page_state *s = page_state(page), new, old; + + /* XXX: this should not be open coded */ + unsigned nr_replicas = inode->ei_inode.bi_data_replicas + ? inode->ei_inode.bi_data_replicas - 1 + : c->opts.data_replicas; + + struct disk_reservation disk_res = bch2_disk_reservation_init(c, + nr_replicas); + struct quota_res quota_res = { 0 }; + int ret = 0; + + /* + * XXX: this could likely be quite a bit simpler, page reservations + * _should_ only be manipulated with page locked: + */ + + old = page_state_cmpxchg(s, new, { + if (new.reserved + ? (new.reservation_replicas < disk_res.nr_replicas) + : (new.sectors < PAGE_SECTORS || + new.nr_replicas < disk_res.nr_replicas || + new.compressed)) { + int sectors = (disk_res.nr_replicas * PAGE_SECTORS - + page_res_sectors(new) - + disk_res.sectors); + + if (sectors > 0) { + ret = bch2_disk_reservation_add(c, &disk_res, sectors, + !check_enospc + ? BCH_DISK_RESERVATION_NOFAIL : 0); + if (unlikely(ret)) + goto err; + } + + new.reserved = 1; + new.reservation_replicas = disk_res.nr_replicas; + } + + if (!new.quota_reserved && + new.sectors + new.dirty_sectors < PAGE_SECTORS) { + ret = bch2_quota_reservation_add(c, inode, "a_res, + PAGE_SECTORS - quota_res.sectors, + check_enospc); + if (unlikely(ret)) + goto err; + + new.quota_reserved = 1; + } + }); + + quota_res.sectors -= (new.quota_reserved - old.quota_reserved) * PAGE_SECTORS; + disk_res.sectors -= page_res_sectors(new) - page_res_sectors(old); +err: + bch2_quota_reservation_put(c, inode, "a_res); + bch2_disk_reservation_put(c, &disk_res); + return ret; +} + +static void bch2_clear_page_bits(struct page *page) +{ + struct bch_inode_info *inode = to_bch_ei(page->mapping->host); + struct bch_fs *c = inode->v.i_sb->s_fs_info; + struct bch_page_state s; + + if (!PagePrivate(page)) + return; + + s.v = xchg(&page_state(page)->v, 0); + ClearPagePrivate(page); + + if (s.dirty_sectors) + i_sectors_acct(c, inode, NULL, -s.dirty_sectors); + + __bch2_put_page_reservation(c, inode, s); +} + +bool bch2_dirty_folio(struct address_space *mapping, struct folio *folio) +{ + struct bch_inode_info *inode = to_bch_ei(mapping->host); + struct bch_fs *c = inode->v.i_sb->s_fs_info; + struct quota_res quota_res = { 0 }; + struct bch_page_state old, new; + + old = page_state_cmpxchg(page_state(&folio->page), new, + new.dirty_sectors = PAGE_SECTORS - new.sectors; + new.quota_reserved = 0; + ); + + quota_res.sectors += old.quota_reserved * PAGE_SECTORS; + + if (old.dirty_sectors != new.dirty_sectors) + i_sectors_acct(c, inode, "a_res, + new.dirty_sectors - old.dirty_sectors); + bch2_quota_reservation_put(c, inode, "a_res); + + return filemap_dirty_folio(mapping, folio); +} + +vm_fault_t bch2_page_fault(struct vm_fault *vmf) +{ + struct file *file = vmf->vma->vm_file; + struct bch_inode_info *inode = file_bch_inode(file); + int ret; + + bch2_pagecache_add_get(&inode->ei_pagecache_lock); + ret = filemap_fault(vmf); + bch2_pagecache_add_put(&inode->ei_pagecache_lock); + + return ret; +} + +vm_fault_t bch2_page_mkwrite(struct vm_fault *vmf) +{ + struct page *page = vmf->page; + struct file *file = vmf->vma->vm_file; + struct bch_inode_info *inode = file_bch_inode(file); + struct address_space *mapping = file->f_mapping; + struct bch_fs *c = inode->v.i_sb->s_fs_info; + int ret = VM_FAULT_LOCKED; + + sb_start_pagefault(inode->v.i_sb); + file_update_time(file); + + /* + * Not strictly necessary, but helps avoid dio writes livelocking in + * write_invalidate_inode_pages_range() - can drop this if/when we get + * a write_invalidate_inode_pages_range() that works without dropping + * page lock before invalidating page + */ + bch2_pagecache_add_get(&inode->ei_pagecache_lock); + + lock_page(page); + if (page->mapping != mapping || + page_offset(page) > i_size_read(&inode->v)) { + unlock_page(page); + ret = VM_FAULT_NOPAGE; + goto out; + } + + if (bch2_get_page_reservation(c, inode, page, true)) { + unlock_page(page); + ret = VM_FAULT_SIGBUS; + goto out; + } + + if (!PageDirty(page)) + set_page_dirty(page); + wait_for_stable_page(page); +out: + bch2_pagecache_add_put(&inode->ei_pagecache_lock); + sb_end_pagefault(inode->v.i_sb); + return ret; +} + +void bch2_invalidate_folio(struct folio *folio, size_t offset, size_t length) +{ + EBUG_ON(!PageLocked(&folio->page)); + EBUG_ON(folio_test_writeback(folio)); + + if (offset || length < folio_size(folio)) + return; + + bch2_clear_page_bits(&folio->page); +} + +bool bch2_release_folio(struct folio *folio, gfp_t gfp_mask) +{ + /* XXX: this can't take locks that are held while we allocate memory */ + EBUG_ON(!PageLocked(&folio->page)); + EBUG_ON(folio_test_writeback(folio)); + + if (folio_test_dirty(folio)) + return false; + + bch2_clear_page_bits(&folio->page); + return true; +} + +/* readpages/writepages: */ + +static bool bio_can_add_page_contig(struct bio *bio, struct page *page) +{ + sector_t offset = (sector_t) page->index << PAGE_SECTOR_SHIFT; + + return bio->bi_vcnt < bio->bi_max_vecs && + bio_end_sector(bio) == offset; +} + +static int bio_add_page_contig(struct bio *bio, struct page *page) +{ + sector_t offset = (sector_t) page->index << PAGE_SECTOR_SHIFT; + + EBUG_ON(!bio->bi_max_vecs); + + if (!bio->bi_vcnt) + bio->bi_iter.bi_sector = offset; + else if (!bio_can_add_page_contig(bio, page)) + return -1; + + __bio_add_page(bio, page, PAGE_SIZE, 0); + return 0; +} + +/* readpage(s): */ + +static void bch2_readpages_end_io(struct bio *bio) +{ + struct bvec_iter_all iter; + struct bio_vec *bv; + + bio_for_each_segment_all(bv, bio, iter) { + struct page *page = bv->bv_page; + + if (!bio->bi_status) { + SetPageUptodate(page); + } else { + ClearPageUptodate(page); + SetPageError(page); + } + unlock_page(page); + } + + bio_put(bio); +} + +static inline void page_state_init_for_read(struct page *page) +{ + struct bch_page_state *s = page_state(page); + + BUG_ON(s->reserved); + s->sectors = 0; + s->compressed = 0; +} + +struct readpages_iter { + struct address_space *mapping; + struct page **pages; + unsigned nr_pages; + unsigned idx; + pgoff_t offset; +}; + +static int readpages_iter_init(struct readpages_iter *iter, + struct readahead_control *ractl) +{ + unsigned i, nr_pages = readahead_count(ractl); + + memset(iter, 0, sizeof(*iter)); + + iter->mapping = ractl->mapping; + iter->offset = readahead_index(ractl); + iter->nr_pages = nr_pages; + + iter->pages = kmalloc_array(nr_pages, sizeof(struct page *), GFP_NOFS); + if (!iter->pages) + return -ENOMEM; + + __readahead_batch(ractl, iter->pages, nr_pages); + for (i = 0; i < nr_pages; i++) { + put_page(iter->pages[i]); + } + + return 0; +} + +static inline struct page *readpage_iter_next(struct readpages_iter *iter) +{ + if (iter->idx >= iter->nr_pages) + return NULL; + + EBUG_ON(iter->pages[iter->idx]->index != iter->offset + iter->idx); + + page_state_init_for_read(iter->pages[iter->idx]); + return iter->pages[iter->idx]; +} + +static void bch2_add_page_sectors(struct bio *bio, struct bkey_s_c k) +{ + struct bvec_iter iter; + struct bio_vec bv; + bool compressed = bch2_extent_is_compressed(k); + unsigned nr_ptrs = bch2_extent_nr_dirty_ptrs(k); + + bio_for_each_segment(bv, bio, iter) { + struct bch_page_state *s = page_state(bv.bv_page); + + /* sectors in @k from the start of this page: */ + unsigned k_sectors = k.k->size - (iter.bi_sector - k.k->p.offset); + + unsigned page_sectors = min(bv.bv_len >> 9, k_sectors); + + s->nr_replicas = !s->sectors + ? nr_ptrs + : min_t(unsigned, s->nr_replicas, nr_ptrs); + + BUG_ON(s->sectors + page_sectors > PAGE_SECTORS); + s->sectors += page_sectors; + + s->compressed |= compressed; + } +} + +static void readpage_bio_extend(struct readpages_iter *iter, + struct bio *bio, u64 offset, + bool get_more) +{ + while (bio_end_sector(bio) < offset && + bio->bi_vcnt < bio->bi_max_vecs) { + pgoff_t page_offset = bio_end_sector(bio) >> PAGE_SECTOR_SHIFT; + struct page *page = readpage_iter_next(iter); + int ret; + + if (page) { + if (iter->offset + iter->idx != page_offset) + break; + + iter->idx++; + } else { + if (!get_more) + break; + + page = xa_load(&iter->mapping->i_pages, page_offset); + if (page && !xa_is_value(page)) + break; + + page = __page_cache_alloc(readahead_gfp_mask(iter->mapping)); + if (!page) + break; + + page_state_init_for_read(page); + + ret = add_to_page_cache_lru(page, iter->mapping, + page_offset, GFP_NOFS); + if (ret) { + ClearPagePrivate(page); + put_page(page); + break; + } + + put_page(page); + } + + __bio_add_page(bio, page, PAGE_SIZE, 0); + } +} + +static void bchfs_read(struct bch_fs *c, struct btree_iter *iter, + struct bch_read_bio *rbio, u64 inum, + struct readpages_iter *readpages_iter) +{ + struct bio *bio = &rbio->bio; + int flags = BCH_READ_RETRY_IF_STALE| + BCH_READ_MAY_PROMOTE; + + rbio->c = c; + rbio->start_time = local_clock(); + + while (1) { + BKEY_PADDED(k) tmp; + struct bkey_s_c k; + unsigned bytes; + + bch2_btree_iter_set_pos(iter, POS(inum, bio->bi_iter.bi_sector)); + + k = bch2_btree_iter_peek_slot(iter); + BUG_ON(!k.k); + + if (IS_ERR(k.k)) { + int ret = bch2_btree_iter_unlock(iter); + BUG_ON(!ret); + bcache_io_error(c, bio, "btree IO error %i", ret); + bio_endio(bio); + return; + } + + bkey_reassemble(&tmp.k, k); + bch2_btree_iter_unlock(iter); + k = bkey_i_to_s_c(&tmp.k); + + if (readpages_iter) { + bool want_full_extent = false; + + if (bkey_extent_is_data(k.k)) { + struct bkey_s_c_extent e = bkey_s_c_to_extent(k); + struct bch_extent_crc_unpacked crc; + const union bch_extent_entry *i; + + extent_for_each_crc(e, crc, i) + want_full_extent |= ((crc.csum_type != 0) | + (crc.compression_type != 0)); + } + + readpage_bio_extend(readpages_iter, + bio, k.k->p.offset, + want_full_extent); + } + + bytes = (min_t(u64, k.k->p.offset, bio_end_sector(bio)) - + bio->bi_iter.bi_sector) << 9; + swap(bio->bi_iter.bi_size, bytes); + + if (bytes == bio->bi_iter.bi_size) + flags |= BCH_READ_LAST_FRAGMENT; + + if (bkey_extent_is_allocation(k.k)) + bch2_add_page_sectors(bio, k); + + bch2_read_extent(c, rbio, k, flags); + + if (flags & BCH_READ_LAST_FRAGMENT) + return; + + swap(bio->bi_iter.bi_size, bytes); + bio_advance(bio, bytes); + } +} + +void bch2_readahead(struct readahead_control *ractl) +{ + struct bch_inode_info *inode = to_bch_ei(ractl->mapping->host); + struct bch_fs *c = inode->v.i_sb->s_fs_info; + struct bch_io_opts opts = io_opts(c, inode); + struct btree_iter iter; + struct page *page; + struct readpages_iter readpages_iter; + int ret; + + ret = readpages_iter_init(&readpages_iter, ractl); + BUG_ON(ret); + + bch2_btree_iter_init(&iter, c, BTREE_ID_EXTENTS, POS_MIN, + BTREE_ITER_SLOTS); + + bch2_pagecache_add_get(&inode->ei_pagecache_lock); + + while ((page = readpage_iter_next(&readpages_iter))) { + pgoff_t index = readpages_iter.offset + readpages_iter.idx; + unsigned n = min_t(unsigned, + readpages_iter.nr_pages - + readpages_iter.idx, + BIO_MAX_VECS); + struct bch_read_bio *rbio = + rbio_init(bio_alloc_bioset(NULL, n, REQ_OP_READ, + GFP_NOFS, &c->bio_read), + opts); + + readpages_iter.idx++; + + rbio->bio.bi_iter.bi_sector = (sector_t) index << PAGE_SECTOR_SHIFT; + rbio->bio.bi_end_io = bch2_readpages_end_io; + __bio_add_page(&rbio->bio, page, PAGE_SIZE, 0); + + bchfs_read(c, &iter, rbio, inode->v.i_ino, &readpages_iter); + } + + bch2_pagecache_add_put(&inode->ei_pagecache_lock); + kfree(readpages_iter.pages); +} + +static void __bchfs_readpage(struct bch_fs *c, struct bch_read_bio *rbio, + u64 inum, struct page *page) +{ + struct btree_iter iter; + + page_state_init_for_read(page); + + rbio->bio.bi_opf = REQ_OP_READ|REQ_SYNC; + bio_add_page_contig(&rbio->bio, page); + + bch2_btree_iter_init(&iter, c, BTREE_ID_EXTENTS, POS_MIN, + BTREE_ITER_SLOTS); + bchfs_read(c, &iter, rbio, inum, NULL); +} + +static void bch2_read_single_page_end_io(struct bio *bio) +{ + complete(bio->bi_private); +} + +static int bch2_read_single_page(struct page *page, + struct address_space *mapping) +{ + struct bch_inode_info *inode = to_bch_ei(mapping->host); + struct bch_fs *c = inode->v.i_sb->s_fs_info; + struct bch_read_bio *rbio; + int ret; + DECLARE_COMPLETION_ONSTACK(done); + + rbio = rbio_init(bio_alloc_bioset(NULL, 1, REQ_OP_READ, GFP_NOFS, &c->bio_read), + io_opts(c, inode)); + rbio->bio.bi_private = &done; + rbio->bio.bi_end_io = bch2_read_single_page_end_io; + + __bchfs_readpage(c, rbio, inode->v.i_ino, page); + wait_for_completion(&done); + + ret = blk_status_to_errno(rbio->bio.bi_status); + bio_put(&rbio->bio); + + if (ret < 0) + return ret; + + SetPageUptodate(page); + return 0; +} + +int bch2_read_folio(struct file *file, struct folio *folio) +{ + struct page *page = &folio->page; + int ret; + + ret = bch2_read_single_page(page, page->mapping); + folio_unlock(folio); + return ret; +} + +/* writepages: */ + +struct bch_writepage_state { + struct bch_writepage_io *io; + struct bch_io_opts opts; +}; + +static inline struct bch_writepage_state bch_writepage_state_init(struct bch_fs *c, + struct bch_inode_info *inode) +{ + return (struct bch_writepage_state) { .opts = io_opts(c, inode) }; +} + +static void bch2_writepage_io_free(struct closure *cl) +{ + struct bch_writepage_io *io = container_of(cl, + struct bch_writepage_io, cl); + + bio_put(&io->op.op.wbio.bio); +} + +static void bch2_writepage_io_done(struct closure *cl) +{ + struct bch_writepage_io *io = container_of(cl, + struct bch_writepage_io, cl); + struct bch_fs *c = io->op.op.c; + struct bio *bio = &io->op.op.wbio.bio; + struct bvec_iter_all iter; + struct bio_vec *bvec; + + if (io->op.op.error) { + bio_for_each_segment_all(bvec, bio, iter) + SetPageError(bvec->bv_page); + set_bit(AS_EIO, &io->op.inode->v.i_mapping->flags); + } + + /* + * racing with fallocate can cause us to add fewer sectors than + * expected - but we shouldn't add more sectors than expected: + */ + BUG_ON(io->op.sectors_added > (s64) io->new_sectors); + + /* + * (error (due to going RO) halfway through a page can screw that up + * slightly) + * XXX wtf? + BUG_ON(io->op.sectors_added - io->new_sectors >= (s64) PAGE_SECTORS); + */ + + /* + * PageWriteback is effectively our ref on the inode - fixup i_blocks + * before calling end_page_writeback: + */ + if (io->op.sectors_added != io->new_sectors) + i_sectors_acct(c, io->op.inode, NULL, + io->op.sectors_added - (s64) io->new_sectors); + + bio_for_each_segment_all(bvec, bio, iter) + end_page_writeback(bvec->bv_page); + + closure_return_with_destructor(&io->cl, bch2_writepage_io_free); +} + +static void bch2_writepage_do_io(struct bch_writepage_state *w) +{ + struct bch_writepage_io *io = w->io; + + w->io = NULL; + closure_call(&io->op.op.cl, bch2_write, NULL, &io->cl); + continue_at(&io->cl, bch2_writepage_io_done, NULL); +} + +/* + * Get a bch_writepage_io and add @page to it - appending to an existing one if + * possible, else allocating a new one: + */ +static void bch2_writepage_io_alloc(struct bch_fs *c, + struct bch_writepage_state *w, + struct bch_inode_info *inode, + struct page *page, + unsigned nr_replicas) +{ + struct bch_write_op *op; + u64 offset = (u64) page->index << PAGE_SECTOR_SHIFT; + + w->io = container_of(bio_alloc_bioset(NULL, BIO_MAX_VECS, + REQ_OP_WRITE, + GFP_NOFS, + &c->writepage_bioset), + struct bch_writepage_io, op.op.wbio.bio); + + closure_init(&w->io->cl, NULL); + w->io->new_sectors = 0; + bch2_fswrite_op_init(&w->io->op, c, inode, w->opts, false); + op = &w->io->op.op; + op->nr_replicas = nr_replicas; + op->res.nr_replicas = nr_replicas; + op->write_point = writepoint_hashed(inode->ei_last_dirtied); + op->pos = POS(inode->v.i_ino, offset); + op->wbio.bio.bi_iter.bi_sector = offset; +} + +static int __bch2_writepage(struct folio *folio, + struct writeback_control *wbc, + void *data) +{ + struct page *page = &folio->page; + struct bch_inode_info *inode = to_bch_ei(page->mapping->host); + struct bch_fs *c = inode->v.i_sb->s_fs_info; + struct bch_writepage_state *w = data; + struct bch_page_state new, old; + unsigned offset; + loff_t i_size = i_size_read(&inode->v); + pgoff_t end_index = i_size >> PAGE_SHIFT; + + EBUG_ON(!PageUptodate(page)); + + /* Is the page fully inside i_size? */ + if (page->index < end_index) + goto do_io; + + /* Is the page fully outside i_size? (truncate in progress) */ + offset = i_size & (PAGE_SIZE - 1); + if (page->index > end_index || !offset) { + unlock_page(page); + return 0; + } + + /* + * The page straddles i_size. It must be zeroed out on each and every + * writepage invocation because it may be mmapped. "A file is mapped + * in multiples of the page size. For a file that is not a multiple of + * the page size, the remaining memory is zeroed when mapped, and + * writes to that region are not written out to the file." + */ + zero_user_segment(page, offset, PAGE_SIZE); +do_io: + /* Before unlocking the page, transfer reservation to w->io: */ + old = page_state_cmpxchg(page_state(page), new, { + EBUG_ON(!new.reserved && + (new.sectors != PAGE_SECTORS || + new.compressed)); + + if (new.reserved) + new.nr_replicas = new.reservation_replicas; + new.reserved = 0; + + new.compressed |= w->opts.compression != 0; + + new.sectors += new.dirty_sectors; + new.dirty_sectors = 0; + }); + + BUG_ON(PageWriteback(page)); + set_page_writeback(page); + unlock_page(page); + + if (w->io && + (w->io->op.op.res.nr_replicas != new.nr_replicas || + !bio_can_add_page_contig(&w->io->op.op.wbio.bio, page))) + bch2_writepage_do_io(w); + + if (!w->io) + bch2_writepage_io_alloc(c, w, inode, page, new.nr_replicas); + + w->io->new_sectors += new.sectors - old.sectors; + + BUG_ON(inode != w->io->op.inode); + BUG_ON(bio_add_page_contig(&w->io->op.op.wbio.bio, page)); + + if (old.reserved) + w->io->op.op.res.sectors += old.reservation_replicas * PAGE_SECTORS; + + w->io->op.new_i_size = i_size; + + if (wbc->sync_mode == WB_SYNC_ALL) + w->io->op.op.wbio.bio.bi_opf |= REQ_SYNC; + + return 0; +} + +int bch2_writepages(struct address_space *mapping, struct writeback_control *wbc) +{ + struct bch_fs *c = mapping->host->i_sb->s_fs_info; + struct bch_writepage_state w = + bch_writepage_state_init(c, to_bch_ei(mapping->host)); + struct blk_plug plug; + int ret; + + blk_start_plug(&plug); + ret = write_cache_pages(mapping, wbc, __bch2_writepage, &w); + if (w.io) + bch2_writepage_do_io(&w); + blk_finish_plug(&plug); + return ret; +} + +int bch2_writepage(struct page *page, struct writeback_control *wbc) +{ + struct bch_fs *c = page->mapping->host->i_sb->s_fs_info; + struct bch_writepage_state w = + bch_writepage_state_init(c, to_bch_ei(page->mapping->host)); + int ret; + + ret = __bch2_writepage(page_folio(page), wbc, &w); + if (w.io) + bch2_writepage_do_io(&w); + + return ret; +} + +/* buffered writes: */ + +int bch2_write_begin(struct file *file, struct address_space *mapping, + loff_t pos, unsigned len, + struct page **pagep, void **fsdata) +{ + struct bch_inode_info *inode = to_bch_ei(mapping->host); + struct bch_fs *c = inode->v.i_sb->s_fs_info; + pgoff_t index = pos >> PAGE_SHIFT; + unsigned offset = pos & (PAGE_SIZE - 1); + struct page *page; + int ret = -ENOMEM; + + BUG_ON(inode_unhashed(&inode->v)); + + bch2_pagecache_add_get(&inode->ei_pagecache_lock); + + page = grab_cache_page_write_begin(mapping, index); + if (!page) + goto err_unlock; + + if (PageUptodate(page)) + goto out; + + /* If we're writing entire page, don't need to read it in first: */ + if (len == PAGE_SIZE) + goto out; + + if (!offset && pos + len >= inode->v.i_size) { + zero_user_segment(page, len, PAGE_SIZE); + flush_dcache_page(page); + goto out; + } + + if (index > inode->v.i_size >> PAGE_SHIFT) { + zero_user_segments(page, 0, offset, offset + len, PAGE_SIZE); + flush_dcache_page(page); + goto out; + } +readpage: + ret = bch2_read_single_page(page, mapping); + if (ret) + goto err; +out: + ret = bch2_get_page_reservation(c, inode, page, true); + if (ret) { + if (!PageUptodate(page)) { + /* + * If the page hasn't been read in, we won't know if we + * actually need a reservation - we don't actually need + * to read here, we just need to check if the page is + * fully backed by uncompressed data: + */ + goto readpage; + } + + goto err; + } + + *pagep = page; + return 0; +err: + unlock_page(page); + put_page(page); + *pagep = NULL; +err_unlock: + bch2_pagecache_add_put(&inode->ei_pagecache_lock); + return ret; +} + +int bch2_write_end(struct file *file, struct address_space *mapping, + loff_t pos, unsigned len, unsigned copied, + struct page *page, void *fsdata) +{ + struct bch_inode_info *inode = to_bch_ei(mapping->host); + struct bch_fs *c = inode->v.i_sb->s_fs_info; + + lockdep_assert_held(&inode->v.i_rwsem); + + if (unlikely(copied < len && !PageUptodate(page))) { + /* + * The page needs to be read in, but that would destroy + * our partial write - simplest thing is to just force + * userspace to redo the write: + */ + zero_user(page, 0, PAGE_SIZE); + flush_dcache_page(page); + copied = 0; + } + + spin_lock(&inode->v.i_lock); + if (pos + copied > inode->v.i_size) + i_size_write(&inode->v, pos + copied); + spin_unlock(&inode->v.i_lock); + + if (copied) { + if (!PageUptodate(page)) + SetPageUptodate(page); + if (!PageDirty(page)) + set_page_dirty(page); + + inode->ei_last_dirtied = (unsigned long) current; + } else { + bch2_put_page_reservation(c, inode, page); + } + + unlock_page(page); + put_page(page); + bch2_pagecache_add_put(&inode->ei_pagecache_lock); + + return copied; +} + +#define WRITE_BATCH_PAGES 32 + +static int __bch2_buffered_write(struct bch_inode_info *inode, + struct address_space *mapping, + struct iov_iter *iter, + loff_t pos, unsigned len) +{ + struct bch_fs *c = inode->v.i_sb->s_fs_info; + struct page *pages[WRITE_BATCH_PAGES]; + unsigned long index = pos >> PAGE_SHIFT; + unsigned offset = pos & (PAGE_SIZE - 1); + unsigned nr_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE); + unsigned i, copied = 0, nr_pages_copied = 0; + int ret = 0; + + BUG_ON(!len); + BUG_ON(nr_pages > ARRAY_SIZE(pages)); + + for (i = 0; i < nr_pages; i++) { + pages[i] = grab_cache_page_write_begin(mapping, index + i); + if (!pages[i]) { + nr_pages = i; + ret = -ENOMEM; + goto out; + } + } + + if (offset && !PageUptodate(pages[0])) { + ret = bch2_read_single_page(pages[0], mapping); + if (ret) + goto out; + } + + if ((pos + len) & (PAGE_SIZE - 1) && + !PageUptodate(pages[nr_pages - 1])) { + if ((index + nr_pages - 1) << PAGE_SHIFT >= inode->v.i_size) { + zero_user(pages[nr_pages - 1], 0, PAGE_SIZE); + } else { + ret = bch2_read_single_page(pages[nr_pages - 1], mapping); + if (ret) + goto out; + } + } + + for (i = 0; i < nr_pages; i++) { + ret = bch2_get_page_reservation(c, inode, pages[i], true); + + if (ret && !PageUptodate(pages[i])) { + ret = bch2_read_single_page(pages[i], mapping); + if (ret) + goto out; + + ret = bch2_get_page_reservation(c, inode, pages[i], true); + } + + if (ret) + goto out; + } + + if (mapping_writably_mapped(mapping)) + for (i = 0; i < nr_pages; i++) + flush_dcache_page(pages[i]); + + while (copied < len) { + struct page *page = pages[(offset + copied) >> PAGE_SHIFT]; + unsigned pg_offset = (offset + copied) & (PAGE_SIZE - 1); + unsigned pg_bytes = min_t(unsigned, len - copied, + PAGE_SIZE - pg_offset); + unsigned pg_copied = copy_page_from_iter_atomic(page, + pg_offset, pg_bytes, iter); + + flush_dcache_page(page); + copied += pg_copied; + + if (pg_copied != pg_bytes) + break; + } + + if (!copied) + goto out; + + nr_pages_copied = DIV_ROUND_UP(offset + copied, PAGE_SIZE); + inode->ei_last_dirtied = (unsigned long) current; + + spin_lock(&inode->v.i_lock); + if (pos + copied > inode->v.i_size) + i_size_write(&inode->v, pos + copied); + spin_unlock(&inode->v.i_lock); + + if (copied < len && + ((offset + copied) & (PAGE_SIZE - 1))) { + struct page *page = pages[(offset + copied) >> PAGE_SHIFT]; + + if (!PageUptodate(page)) { + zero_user(page, 0, PAGE_SIZE); + copied -= (offset + copied) & (PAGE_SIZE - 1); + } + } +out: + for (i = 0; i < nr_pages_copied; i++) { + if (!PageUptodate(pages[i])) + SetPageUptodate(pages[i]); + if (!PageDirty(pages[i])) + set_page_dirty(pages[i]); + unlock_page(pages[i]); + put_page(pages[i]); + } + + for (i = nr_pages_copied; i < nr_pages; i++) { + if (!PageDirty(pages[i])) + bch2_put_page_reservation(c, inode, pages[i]); + unlock_page(pages[i]); + put_page(pages[i]); + } + + return copied ?: ret; +} + +static ssize_t bch2_buffered_write(struct kiocb *iocb, struct iov_iter *iter) +{ + struct file *file = iocb->ki_filp; + struct address_space *mapping = file->f_mapping; + struct bch_inode_info *inode = file_bch_inode(file); + loff_t pos = iocb->ki_pos; + ssize_t written = 0; + int ret = 0; + + bch2_pagecache_add_get(&inode->ei_pagecache_lock); + + do { + unsigned offset = pos & (PAGE_SIZE - 1); + unsigned bytes = min_t(unsigned long, iov_iter_count(iter), + PAGE_SIZE * WRITE_BATCH_PAGES - offset); +again: + /* + * Bring in the user page that we will copy from _first_. + * Otherwise there's a nasty deadlock on copying from the + * same page as we're writing to, without it being marked + * up-to-date. + * + * Not only is this an optimisation, but it is also required + * to check that the address is actually valid, when atomic + * usercopies are used, below. + */ + if (unlikely(fault_in_iov_iter_readable(iter, bytes))) { + bytes = min_t(unsigned long, iov_iter_count(iter), + PAGE_SIZE - offset); + + if (unlikely(fault_in_iov_iter_readable(iter, bytes))) { + ret = -EFAULT; + break; + } + } + + if (unlikely(fatal_signal_pending(current))) { + ret = -EINTR; + break; + } + + ret = __bch2_buffered_write(inode, mapping, iter, pos, bytes); + if (unlikely(ret < 0)) + break; + + cond_resched(); + + if (unlikely(ret == 0)) { + /* + * If we were unable to copy any data at all, we must + * fall back to a single segment length write. + * + * If we didn't fallback here, we could livelock + * because not all segments in the iov can be copied at + * once without a pagefault. + */ + bytes = min_t(unsigned long, PAGE_SIZE - offset, + iov_iter_single_seg_count(iter)); + goto again; + } + pos += ret; + written += ret; + + balance_dirty_pages_ratelimited(mapping); + } while (iov_iter_count(iter)); + + bch2_pagecache_add_put(&inode->ei_pagecache_lock); + + return written ? written : ret; +} + +/* O_DIRECT reads */ + +static void bch2_dio_read_complete(struct closure *cl) +{ + struct dio_read *dio = container_of(cl, struct dio_read, cl); + + dio->req->ki_complete(dio->req, dio->ret); + bio_check_pages_dirty(&dio->rbio.bio); /* transfers ownership */ +} + +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) +{ + bch2_direct_IO_read_endio(bio); + bio_check_pages_dirty(bio); /* transfers ownership */ +} + +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 = io_opts(c, inode); + 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; + + 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, + iov_iter_npages(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->req = req; + dio->ret = ret; + + goto start; + while (iter->count) { + bio = bio_alloc_bioset(NULL, + iov_iter_npages(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; + bio_set_pages_dirty(bio); + + if (iter->count) + closure_get(&dio->cl); + + bch2_read(c, rbio_init(bio, opts), inode->v.i_ino); + } + + iter->count += shorten; + + if (sync) { + closure_sync(&dio->cl); + closure_debug_destroy(&dio->cl); + ret = dio->ret; + bio_check_pages_dirty(&dio->rbio.bio); /* transfers ownership */ + 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; + + ret = filemap_write_and_wait_range(mapping, + iocb->ki_pos, + iocb->ki_pos + count - 1); + if (ret < 0) + return ret; + + 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->ei_pagecache_lock); + ret = generic_file_read_iter(iocb, iter); + bch2_pagecache_add_put(&inode->ei_pagecache_lock); + } + + return ret; +} + +/* O_DIRECT writes */ + +/* + * 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)) { + iov = kmalloc_array(dio->iter.nr_segs, sizeof(*iov), + GFP_KERNEL); + if (unlikely(!iov)) + return -ENOMEM; + + dio->free_iov = true; + } + + memcpy(iov, dio->iter.__iov, dio->iter.nr_segs * sizeof(*iov)); + dio->iter.__iov = iov; + return 0; +} + +static void bch2_dio_write_loop_async(struct closure *); + +static long bch2_dio_write_loop(struct dio_write *dio) +{ + struct kiocb *req = dio->req; + struct address_space *mapping = req->ki_filp->f_mapping; + struct bch_inode_info *inode = dio->iop.inode; + struct bio *bio = &dio->iop.op.wbio.bio; + struct bvec_iter_all iter; + struct bio_vec *bv; + bool sync; + long ret; + + if (dio->loop) + goto loop; + + inode_dio_begin(&inode->v); + bch2_pagecache_block_get(&inode->ei_pagecache_lock); + + /* Write and invalidate pagecache range that we're writing to: */ + ret = write_invalidate_inode_pages_range(mapping, req->ki_pos, + req->ki_pos + iov_iter_count(&dio->iter) - 1); + if (unlikely(ret)) + goto err; + + while (1) { + if (current != dio->task) + kthread_use_mm(dio->task->mm); + BUG_ON(current->faults_disabled_mapping); + current->faults_disabled_mapping = mapping; + + ret = bio_iov_iter_get_pages(bio, &dio->iter); + + current->faults_disabled_mapping = NULL; + if (current != dio->task) + kthread_unuse_mm(dio->task->mm); + + if (unlikely(ret < 0)) + goto err; + + /* gup might have faulted pages back in: */ + ret = write_invalidate_inode_pages_range(mapping, + req->ki_pos + (dio->iop.op.written << 9), + req->ki_pos + iov_iter_count(&dio->iter) - 1); + if (unlikely(ret)) + goto err; + + dio->iop.op.pos = POS(inode->v.i_ino, + (req->ki_pos >> 9) + dio->iop.op.written); + + task_io_account_write(bio->bi_iter.bi_size); + + closure_call(&dio->iop.op.cl, bch2_write, NULL, &dio->cl); + + if (!dio->sync && !dio->loop && dio->iter.count) { + if (bch2_dio_write_copy_iov(dio)) { + dio->iop.op.error = -ENOMEM; + goto err_wait_io; + } + } +err_wait_io: + dio->loop = true; + + if (!dio->sync) { + continue_at(&dio->cl, bch2_dio_write_loop_async, NULL); + return -EIOCBQUEUED; + } + + closure_sync(&dio->cl); +loop: + bio_for_each_segment_all(bv, bio, iter) + put_page(bv->bv_page); + if (!dio->iter.count || dio->iop.op.error) + break; + bio_reset(bio, NULL, REQ_OP_WRITE); + } + + ret = dio->iop.op.error ?: ((long) dio->iop.op.written << 9); +err: + bch2_pagecache_block_put(&inode->ei_pagecache_lock); + bch2_disk_reservation_put(dio->iop.op.c, &dio->iop.op.res); + bch2_quota_reservation_put(dio->iop.op.c, inode, &dio->quota_res); + + if (dio->free_iov) + kfree(dio->iter.__iov); + + closure_debug_destroy(&dio->cl); + + sync = dio->sync; + bio_put(bio); + + /* inode->i_dio_count is our ref on inode and thus bch_fs */ + inode_dio_end(&inode->v); + + if (!sync) { + req->ki_complete(req, ret); + ret = -EIOCBQUEUED; + } + return ret; +} + +static void bch2_dio_write_loop_async(struct closure *cl) +{ + struct dio_write *dio = container_of(cl, struct dio_write, cl); + + bch2_dio_write_loop(dio); +} + +static noinline +ssize_t bch2_direct_write(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 dio_write *dio; + struct bio *bio; + loff_t offset = req->ki_pos; + ssize_t ret; + + lockdep_assert_held(&inode->v.i_rwsem); + + if (unlikely(!iter->count)) + return 0; + + if (unlikely((offset|iter->count) & (block_bytes(c) - 1))) + return -EINVAL; + + bio = bio_alloc_bioset(NULL, + iov_iter_npages(iter, BIO_MAX_VECS), + REQ_OP_WRITE, + GFP_KERNEL, + &c->dio_write_bioset); + dio = container_of(bio, struct dio_write, iop.op.wbio.bio); + closure_init(&dio->cl, NULL); + dio->req = req; + dio->task = current; + dio->loop = false; + dio->sync = is_sync_kiocb(req) || + offset + iter->count > inode->v.i_size; + dio->free_iov = false; + dio->quota_res.sectors = 0; + dio->iter = *iter; + bch2_fswrite_op_init(&dio->iop, c, inode, io_opts(c, inode), true); + dio->iop.op.write_point = writepoint_hashed((unsigned long) dio->task); + dio->iop.op.flags |= BCH_WRITE_NOPUT_RESERVATION; + + if ((req->ki_flags & IOCB_DSYNC) && + !c->opts.journal_flush_disabled) + dio->iop.op.flags |= BCH_WRITE_FLUSH; + + ret = bch2_quota_reservation_add(c, inode, &dio->quota_res, + iter->count >> 9, true); + if (unlikely(ret)) + goto err; + + ret = bch2_disk_reservation_get(c, &dio->iop.op.res, iter->count >> 9, + dio->iop.op.opts.data_replicas, 0); + if (unlikely(ret)) { + if (bch2_check_range_allocated(c, POS(inode->v.i_ino, + offset >> 9), + iter->count >> 9)) + goto err; + + dio->iop.unalloc = true; + } + + dio->iop.op.nr_replicas = dio->iop.op.res.nr_replicas; + + return bch2_dio_write_loop(dio); +err: + bch2_disk_reservation_put(c, &dio->iop.op.res); + bch2_quota_reservation_put(c, inode, &dio->quota_res); + closure_debug_destroy(&dio->cl); + bio_put(bio); + return ret; +} + +static ssize_t __bch2_write_iter(struct kiocb *iocb, struct iov_iter *from) +{ + struct file *file = iocb->ki_filp; + ssize_t ret; + + if (iocb->ki_flags & IOCB_DIRECT) + return bch2_direct_write(iocb, from); + + ret = file_remove_privs(file); + if (ret) + return ret; + + ret = file_update_time(file); + if (ret) + return ret; + + ret = iocb->ki_flags & IOCB_DIRECT + ? bch2_direct_write(iocb, from) + : bch2_buffered_write(iocb, from); + + if (likely(ret > 0)) + iocb->ki_pos += ret; + + return ret; +} + +ssize_t bch2_write_iter(struct kiocb *iocb, struct iov_iter *from) +{ + struct bch_inode_info *inode = file_bch_inode(iocb->ki_filp); + bool direct = iocb->ki_flags & IOCB_DIRECT; + ssize_t ret; + + inode_lock(&inode->v); + ret = generic_write_checks(iocb, from); + if (ret > 0) + ret = __bch2_write_iter(iocb, from); + inode_unlock(&inode->v); + + if (ret > 0 && !direct) + ret = generic_write_sync(iocb, ret); + + return ret; +} + +/* fsync: */ + +int bch2_fsync(struct file *file, loff_t start, loff_t end, int datasync) +{ + struct bch_inode_info *inode = file_bch_inode(file); + struct bch_fs *c = inode->v.i_sb->s_fs_info; + int ret; + + ret = file_write_and_wait_range(file, start, end); + if (ret) + return ret; + + if (datasync && !(inode->v.i_state & I_DIRTY_DATASYNC)) + goto out; + + ret = sync_inode_metadata(&inode->v, 1); + if (ret) + return ret; +out: + if (c->opts.journal_flush_disabled) + return 0; + + return bch2_journal_flush_seq(&c->journal, inode->ei_journal_seq); +} + +/* truncate: */ + +static inline int range_has_data(struct bch_fs *c, + struct bpos start, + struct bpos end) +{ + + struct btree_iter iter; + struct bkey_s_c k; + int ret = 0; + + for_each_btree_key(&iter, c, BTREE_ID_EXTENTS, + start, 0, k) { + if (bkey_cmp(bkey_start_pos(k.k), end) >= 0) + break; + + if (bkey_extent_is_data(k.k)) { + ret = 1; + break; + } + } + + return bch2_btree_iter_unlock(&iter) ?: ret; +} + +static int __bch2_truncate_page(struct bch_inode_info *inode, + pgoff_t index, loff_t start, loff_t end) +{ + struct bch_fs *c = inode->v.i_sb->s_fs_info; + struct address_space *mapping = inode->v.i_mapping; + unsigned start_offset = start & (PAGE_SIZE - 1); + unsigned end_offset = ((end - 1) & (PAGE_SIZE - 1)) + 1; + struct page *page; + int ret = 0; + + /* Page boundary? Nothing to do */ + if (!((index == start >> PAGE_SHIFT && start_offset) || + (index == end >> PAGE_SHIFT && end_offset != PAGE_SIZE))) + return 0; + + /* Above i_size? */ + if (index << PAGE_SHIFT >= inode->v.i_size) + return 0; + + page = find_lock_page(mapping, index); + if (!page) { + /* + * XXX: we're doing two index lookups when we end up reading the + * page + */ + ret = range_has_data(c, + POS(inode->v.i_ino, index << PAGE_SECTOR_SHIFT), + POS(inode->v.i_ino, (index + 1) << PAGE_SECTOR_SHIFT)); + if (ret <= 0) + return ret; + + page = find_or_create_page(mapping, index, GFP_KERNEL); + if (unlikely(!page)) { + ret = -ENOMEM; + goto out; + } + } + + if (!PageUptodate(page)) { + ret = bch2_read_single_page(page, mapping); + if (ret) + goto unlock; + } + + /* + * Bit of a hack - we don't want truncate to fail due to -ENOSPC. + * + * XXX: because we aren't currently tracking whether the page has actual + * data in it (vs. just 0s, or only partially written) this wrong. ick. + */ + ret = bch2_get_page_reservation(c, inode, page, false); + BUG_ON(ret); + + if (index == start >> PAGE_SHIFT && + index == end >> PAGE_SHIFT) + zero_user_segment(page, start_offset, end_offset); + else if (index == start >> PAGE_SHIFT) + zero_user_segment(page, start_offset, PAGE_SIZE); + else if (index == end >> PAGE_SHIFT) + zero_user_segment(page, 0, end_offset); + + if (!PageDirty(page)) + set_page_dirty(page); +unlock: + unlock_page(page); + put_page(page); +out: + return ret; +} + +static int bch2_truncate_page(struct bch_inode_info *inode, loff_t from) +{ + return __bch2_truncate_page(inode, from >> PAGE_SHIFT, + from, from + PAGE_SIZE); +} + +static int bch2_extend(struct bch_inode_info *inode, struct iattr *iattr) +{ + struct bch_fs *c = inode->v.i_sb->s_fs_info; + struct address_space *mapping = inode->v.i_mapping; + int ret; + + ret = filemap_write_and_wait_range(mapping, + inode->ei_inode.bi_size, S64_MAX); + if (ret) + return ret; + + truncate_setsize(&inode->v, iattr->ia_size); + /* ATTR_MODE will never be set here, ns argument isn't needed: */ + setattr_copy(NULL, &inode->v, iattr); + + mutex_lock(&inode->ei_update_lock); + inode_set_ctime_current(&inode->v); + inode->v.i_mtime = inode_get_ctime(&inode->v); + ret = bch2_write_inode_size(c, inode, inode->v.i_size); + mutex_unlock(&inode->ei_update_lock); + + return ret; +} + +int bch2_truncate(struct bch_inode_info *inode, struct iattr *iattr) +{ + struct bch_fs *c = inode->v.i_sb->s_fs_info; + struct address_space *mapping = inode->v.i_mapping; + struct i_sectors_hook i_sectors_hook = + i_sectors_hook_init(inode, BCH_INODE_I_SIZE_DIRTY); + bool shrink; + int ret = 0; + + inode_dio_wait(&inode->v); + bch2_pagecache_block_get(&inode->ei_pagecache_lock); + + BUG_ON(inode->v.i_size < inode->ei_inode.bi_size); + + shrink = iattr->ia_size <= inode->v.i_size; + + if (!shrink) { + ret = bch2_extend(inode, iattr); + goto err_put_pagecache; + } + + ret = bch2_truncate_page(inode, iattr->ia_size); + if (unlikely(ret)) + goto err_put_pagecache; + + if (iattr->ia_size > inode->ei_inode.bi_size) + ret = filemap_write_and_wait_range(mapping, + inode->ei_inode.bi_size, + iattr->ia_size - 1); + else if (iattr->ia_size & (PAGE_SIZE - 1)) + ret = filemap_write_and_wait_range(mapping, + round_down(iattr->ia_size, PAGE_SIZE), + iattr->ia_size - 1); + if (ret) + goto err_put_pagecache; + + i_sectors_hook.new_i_size = iattr->ia_size; + + ret = i_sectors_dirty_start(c, &i_sectors_hook); + if (unlikely(ret)) + goto err_put_pagecache; + + truncate_setsize(&inode->v, iattr->ia_size); + + ret = bch2_inode_truncate(c, inode->v.i_ino, + round_up(iattr->ia_size, PAGE_SIZE) >> 9, + &i_sectors_hook.hook, + &inode->ei_journal_seq); + if (unlikely(ret)) + goto err_put_sectors_dirty; + + /* ATTR_MODE will never be set here, ns argument isn't needed: */ + setattr_copy(NULL, &inode->v, iattr); + inode_set_ctime_current(&inode->v); + inode->v.i_mtime = inode_get_ctime(&inode->v); +out: + ret = i_sectors_dirty_finish(c, &i_sectors_hook) ?: ret; +err_put_pagecache: + bch2_pagecache_block_put(&inode->ei_pagecache_lock); + return ret; +err_put_sectors_dirty: + /* + * On error - in particular, bch2_truncate_page() error - don't clear + * I_SIZE_DIRTY, as we've left data above i_size!: + */ + i_sectors_hook.flags &= ~BCH_INODE_I_SIZE_DIRTY; + goto out; +} + +/* fallocate: */ + +static long bch2_fpunch(struct bch_inode_info *inode, loff_t offset, loff_t len) +{ + struct bch_fs *c = inode->v.i_sb->s_fs_info; + u64 ino = inode->v.i_ino; + u64 discard_start = round_up(offset, PAGE_SIZE) >> 9; + u64 discard_end = round_down(offset + len, PAGE_SIZE) >> 9; + int ret = 0; + + inode_lock(&inode->v); + inode_dio_wait(&inode->v); + bch2_pagecache_block_get(&inode->ei_pagecache_lock); + + ret = __bch2_truncate_page(inode, + offset >> PAGE_SHIFT, + offset, offset + len); + if (unlikely(ret)) + goto err; + + if (offset >> PAGE_SHIFT != + (offset + len) >> PAGE_SHIFT) { + ret = __bch2_truncate_page(inode, + (offset + len) >> PAGE_SHIFT, + offset, offset + len); + if (unlikely(ret)) + goto err; + } + + truncate_pagecache_range(&inode->v, offset, offset + len - 1); + + if (discard_start < discard_end) { + /* + * We need to pass in a disk reservation here because we might + * be splitting a compressed extent into two. This isn't a + * problem with truncate because truncate will never split an + * extent, only truncate it... + */ + struct disk_reservation disk_res = + bch2_disk_reservation_init(c, 0); + struct i_sectors_hook i_sectors_hook = + i_sectors_hook_init(inode, 0); + int ret; + + ret = i_sectors_dirty_start(c, &i_sectors_hook); + if (unlikely(ret)) + goto err; + + ret = bch2_btree_delete_range(c, + BTREE_ID_EXTENTS, + POS(ino, discard_start), + POS(ino, discard_end), + ZERO_VERSION, + &disk_res, + &i_sectors_hook.hook, + &inode->ei_journal_seq); + + ret = i_sectors_dirty_finish(c, &i_sectors_hook) ?: ret; + } +err: + bch2_pagecache_block_put(&inode->ei_pagecache_lock); + inode_unlock(&inode->v); + + return ret; +} + +static long bch2_fcollapse(struct bch_inode_info *inode, + loff_t offset, loff_t len) +{ + struct bch_fs *c = inode->v.i_sb->s_fs_info; + struct address_space *mapping = inode->v.i_mapping; + struct btree_iter src; + struct btree_iter dst; + BKEY_PADDED(k) copy; + struct bkey_s_c k; + struct i_sectors_hook i_sectors_hook = i_sectors_hook_init(inode, 0); + loff_t new_size; + int ret; + + if ((offset | len) & (block_bytes(c) - 1)) + return -EINVAL; + + bch2_btree_iter_init(&dst, c, BTREE_ID_EXTENTS, + POS(inode->v.i_ino, offset >> 9), + BTREE_ITER_SLOTS|BTREE_ITER_INTENT); + /* position will be set from dst iter's position: */ + bch2_btree_iter_init(&src, c, BTREE_ID_EXTENTS, POS_MIN, + BTREE_ITER_SLOTS); + bch2_btree_iter_link(&src, &dst); + + /* + * We need i_mutex to keep the page cache consistent with the extents + * btree, and the btree consistent with i_size - we don't need outside + * locking for the extents btree itself, because we're using linked + * iterators + */ + inode_lock(&inode->v); + inode_dio_wait(&inode->v); + bch2_pagecache_block_get(&inode->ei_pagecache_lock); + + ret = -EINVAL; + if (offset + len >= inode->v.i_size) + goto err; + + if (inode->v.i_size < len) + goto err; + + new_size = inode->v.i_size - len; + + ret = write_invalidate_inode_pages_range(mapping, offset, LLONG_MAX); + if (ret) + goto err; + + ret = i_sectors_dirty_start(c, &i_sectors_hook); + if (ret) + goto err; + + while (bkey_cmp(dst.pos, + POS(inode->v.i_ino, + round_up(new_size, PAGE_SIZE) >> 9)) < 0) { + struct disk_reservation disk_res; + + bch2_btree_iter_set_pos(&src, + POS(dst.pos.inode, dst.pos.offset + (len >> 9))); + + k = bch2_btree_iter_peek_slot(&src); + if ((ret = btree_iter_err(k))) + goto btree_iter_err; + + bkey_reassemble(©.k, k); + + bch2_cut_front(src.pos, ©.k); + copy.k.k.p.offset -= len >> 9; + + BUG_ON(bkey_cmp(dst.pos, bkey_start_pos(©.k.k))); + + ret = bch2_disk_reservation_get(c, &disk_res, copy.k.k.size, + bch2_extent_nr_dirty_ptrs(bkey_i_to_s_c(©.k)), + BCH_DISK_RESERVATION_NOFAIL); + BUG_ON(ret); + + ret = bch2_btree_insert_at(c, &disk_res, &i_sectors_hook.hook, + &inode->ei_journal_seq, + BTREE_INSERT_ATOMIC| + BTREE_INSERT_NOFAIL, + BTREE_INSERT_ENTRY(&dst, ©.k)); + bch2_disk_reservation_put(c, &disk_res); +btree_iter_err: + if (ret == -EINTR) + ret = 0; + if (ret) { + bch2_btree_iter_unlock(&src); + bch2_btree_iter_unlock(&dst); + goto err_put_sectors_dirty; + } + /* + * XXX: if we error here we've left data with multiple + * pointers... which isn't a _super_ serious problem... + */ + + bch2_btree_iter_cond_resched(&src); + } + + bch2_btree_iter_unlock(&src); + bch2_btree_iter_unlock(&dst); + + ret = bch2_inode_truncate(c, inode->v.i_ino, + round_up(new_size, block_bytes(c)) >> 9, + &i_sectors_hook.hook, + &inode->ei_journal_seq); + if (ret) + goto err_put_sectors_dirty; + + i_sectors_hook.new_i_size = new_size; +err_put_sectors_dirty: + ret = i_sectors_dirty_finish(c, &i_sectors_hook) ?: ret; +err: + bch2_pagecache_block_put(&inode->ei_pagecache_lock); + inode_unlock(&inode->v); + return ret; +} + +static long bch2_fallocate(struct bch_inode_info *inode, int mode, + loff_t offset, loff_t len) +{ + struct address_space *mapping = inode->v.i_mapping; + struct bch_fs *c = inode->v.i_sb->s_fs_info; + struct i_sectors_hook i_sectors_hook = i_sectors_hook_init(inode, 0); + struct btree_iter iter; + struct bpos end_pos; + loff_t block_start, block_end; + loff_t end = offset + len; + unsigned sectors; + unsigned replicas = io_opts(c, inode).data_replicas; + int ret; + + bch2_btree_iter_init(&iter, c, BTREE_ID_EXTENTS, POS_MIN, + BTREE_ITER_SLOTS|BTREE_ITER_INTENT); + + inode_lock(&inode->v); + inode_dio_wait(&inode->v); + bch2_pagecache_block_get(&inode->ei_pagecache_lock); + + if (!(mode & FALLOC_FL_KEEP_SIZE) && end > inode->v.i_size) { + ret = inode_newsize_ok(&inode->v, end); + if (ret) + goto err; + } + + if (mode & FALLOC_FL_ZERO_RANGE) { + ret = __bch2_truncate_page(inode, + offset >> PAGE_SHIFT, + offset, end); + + if (!ret && + offset >> PAGE_SHIFT != end >> PAGE_SHIFT) + ret = __bch2_truncate_page(inode, + end >> PAGE_SHIFT, + offset, end); + + if (unlikely(ret)) + goto err; + + truncate_pagecache_range(&inode->v, offset, end - 1); + + block_start = round_up(offset, PAGE_SIZE); + block_end = round_down(end, PAGE_SIZE); + } else { + block_start = round_down(offset, PAGE_SIZE); + block_end = round_up(end, PAGE_SIZE); + } + + bch2_btree_iter_set_pos(&iter, POS(inode->v.i_ino, block_start >> 9)); + end_pos = POS(inode->v.i_ino, block_end >> 9); + + ret = i_sectors_dirty_start(c, &i_sectors_hook); + if (unlikely(ret)) + goto err; + + while (bkey_cmp(iter.pos, end_pos) < 0) { + struct disk_reservation disk_res = { 0 }; + struct bkey_i_reservation reservation; + struct bkey_s_c k; + + k = bch2_btree_iter_peek_slot(&iter); + if ((ret = btree_iter_err(k))) + goto btree_iter_err; + + /* already reserved */ + if (k.k->type == BCH_RESERVATION && + bkey_s_c_to_reservation(k).v->nr_replicas >= replicas) { + bch2_btree_iter_next_slot(&iter); + continue; + } + + if (bkey_extent_is_data(k.k)) { + if (!(mode & FALLOC_FL_ZERO_RANGE)) { + bch2_btree_iter_next_slot(&iter); + continue; + } + } + + bkey_reservation_init(&reservation.k_i); + reservation.k.type = BCH_RESERVATION; + reservation.k.p = k.k->p; + reservation.k.size = k.k->size; + + bch2_cut_front(iter.pos, &reservation.k_i); + bch2_cut_back(end_pos, &reservation.k); + + sectors = reservation.k.size; + reservation.v.nr_replicas = bch2_extent_nr_dirty_ptrs(k); + + if (!bkey_extent_is_allocation(k.k)) { + ret = bch2_quota_reservation_add(c, inode, + &i_sectors_hook.quota_res, + sectors, true); + if (unlikely(ret)) + goto btree_iter_err; + } + + if (reservation.v.nr_replicas < replicas || + bch2_extent_is_compressed(k)) { + ret = bch2_disk_reservation_get(c, &disk_res, sectors, + replicas, 0); + if (unlikely(ret)) + goto btree_iter_err; + + reservation.v.nr_replicas = disk_res.nr_replicas; + } + + ret = bch2_btree_insert_at(c, &disk_res, &i_sectors_hook.hook, + &inode->ei_journal_seq, + BTREE_INSERT_ATOMIC| + BTREE_INSERT_NOFAIL, + BTREE_INSERT_ENTRY(&iter, &reservation.k_i)); + bch2_disk_reservation_put(c, &disk_res); +btree_iter_err: + if (ret == -EINTR) + ret = 0; + if (ret) { + bch2_btree_iter_unlock(&iter); + goto err_put_sectors_dirty; + } + + } + bch2_btree_iter_unlock(&iter); + + ret = i_sectors_dirty_finish(c, &i_sectors_hook) ?: ret; + + if (!(mode & FALLOC_FL_KEEP_SIZE) && + end > inode->v.i_size) { + i_size_write(&inode->v, end); + + mutex_lock(&inode->ei_update_lock); + ret = bch2_write_inode_size(c, inode, inode->v.i_size); + mutex_unlock(&inode->ei_update_lock); + } + + /* blech */ + if ((mode & FALLOC_FL_KEEP_SIZE) && + (mode & FALLOC_FL_ZERO_RANGE) && + inode->ei_inode.bi_size != inode->v.i_size) { + /* sync appends.. */ + ret = filemap_write_and_wait_range(mapping, + inode->ei_inode.bi_size, S64_MAX); + if (ret) + goto err; + + if (inode->ei_inode.bi_size != inode->v.i_size) { + mutex_lock(&inode->ei_update_lock); + ret = bch2_write_inode_size(c, inode, inode->v.i_size); + mutex_unlock(&inode->ei_update_lock); + } + } + + bch2_pagecache_block_put(&inode->ei_pagecache_lock); + inode_unlock(&inode->v); + + return 0; +err_put_sectors_dirty: + ret = i_sectors_dirty_finish(c, &i_sectors_hook) ?: ret; +err: + bch2_pagecache_block_put(&inode->ei_pagecache_lock); + inode_unlock(&inode->v); + return ret; +} + +long bch2_fallocate_dispatch(struct file *file, int mode, + loff_t offset, loff_t len) +{ + struct bch_inode_info *inode = file_bch_inode(file); + + if (!(mode & ~(FALLOC_FL_KEEP_SIZE|FALLOC_FL_ZERO_RANGE))) + return bch2_fallocate(inode, mode, offset, len); + + if (mode == (FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE)) + return bch2_fpunch(inode, offset, len); + + if (mode == FALLOC_FL_COLLAPSE_RANGE) + return bch2_fcollapse(inode, offset, len); + + return -EOPNOTSUPP; +} + +/* fseek: */ + +static bool folio_is_data(struct folio *folio) +{ + /* XXX: should only have to check PageDirty */ + return folio_test_private(folio) && + (page_state(&folio->page)->sectors || + page_state(&folio->page)->dirty_sectors); +} + +static loff_t bch2_next_pagecache_data(struct inode *vinode, + loff_t start_offset, + loff_t end_offset) +{ + struct folio_batch fbatch; + pgoff_t start_index = start_offset >> PAGE_SHIFT; + pgoff_t end_index = end_offset >> PAGE_SHIFT; + pgoff_t index = start_index; + unsigned i; + + folio_batch_init(&fbatch); + + while (filemap_get_folios(vinode->i_mapping, + &index, end_index, &fbatch)) { + for (i = 0; i < folio_batch_count(&fbatch); i++) { + struct folio *folio = fbatch.folios[i]; + + folio_lock(folio); + if (folio_is_data(folio)) { + end_offset = + min(end_offset, + max(start_offset, + ((loff_t) index) << PAGE_SHIFT)); + folio_unlock(folio); + folio_batch_release(&fbatch); + return end_offset; + } + folio_unlock(folio); + } + folio_batch_release(&fbatch); + cond_resched(); + } + + return end_offset; +} + +static loff_t bch2_seek_data(struct file *file, u64 offset) +{ + struct bch_inode_info *inode = file_bch_inode(file); + struct bch_fs *c = inode->v.i_sb->s_fs_info; + struct btree_iter iter; + struct bkey_s_c k; + u64 isize, next_data = MAX_LFS_FILESIZE; + int ret; + + isize = i_size_read(&inode->v); + if (offset >= isize) + return -ENXIO; + + for_each_btree_key(&iter, c, BTREE_ID_EXTENTS, + POS(inode->v.i_ino, offset >> 9), 0, k) { + if (k.k->p.inode != inode->v.i_ino) { + break; + } else if (bkey_extent_is_data(k.k)) { + next_data = max(offset, bkey_start_offset(k.k) << 9); + break; + } else if (k.k->p.offset >> 9 > isize) + break; + } + + ret = bch2_btree_iter_unlock(&iter); + if (ret) + return ret; + + if (next_data > offset) + next_data = bch2_next_pagecache_data(&inode->v, + offset, next_data); + + if (next_data > isize) + return -ENXIO; + + return vfs_setpos(file, next_data, MAX_LFS_FILESIZE); +} + +static bool page_slot_is_data(struct address_space *mapping, pgoff_t index) +{ + struct page *page; + bool ret; + + page = find_lock_page(mapping, index); + if (!page) + return false; + + ret = folio_is_data(page_folio(page)); + unlock_page(page); + + return ret; +} + +static loff_t bch2_next_pagecache_hole(struct inode *vinode, + loff_t start_offset, + loff_t end_offset) +{ + struct address_space *mapping = vinode->i_mapping; + pgoff_t index; + + for (index = start_offset >> PAGE_SHIFT; + index < end_offset >> PAGE_SHIFT; + index++) + if (!page_slot_is_data(mapping, index)) + end_offset = max(start_offset, + ((loff_t) index) << PAGE_SHIFT); + + return end_offset; +} + +static loff_t bch2_seek_hole(struct file *file, u64 offset) +{ + struct bch_inode_info *inode = file_bch_inode(file); + struct bch_fs *c = inode->v.i_sb->s_fs_info; + struct btree_iter iter; + struct bkey_s_c k; + u64 isize, next_hole = MAX_LFS_FILESIZE; + int ret; + + isize = i_size_read(&inode->v); + if (offset >= isize) + return -ENXIO; + + for_each_btree_key(&iter, c, BTREE_ID_EXTENTS, + POS(inode->v.i_ino, offset >> 9), + BTREE_ITER_SLOTS, k) { + if (k.k->p.inode != inode->v.i_ino) { + next_hole = bch2_next_pagecache_hole(&inode->v, + offset, MAX_LFS_FILESIZE); + break; + } else if (!bkey_extent_is_data(k.k)) { + next_hole = bch2_next_pagecache_hole(&inode->v, + max(offset, bkey_start_offset(k.k) << 9), + k.k->p.offset << 9); + + if (next_hole < k.k->p.offset << 9) + break; + } else { + offset = max(offset, bkey_start_offset(k.k) << 9); + } + } + + ret = bch2_btree_iter_unlock(&iter); + if (ret) + return ret; + + if (next_hole > isize) + next_hole = isize; + + return vfs_setpos(file, next_hole, MAX_LFS_FILESIZE); +} + +loff_t bch2_llseek(struct file *file, loff_t offset, int whence) +{ + switch (whence) { + case SEEK_SET: + case SEEK_CUR: + case SEEK_END: + return generic_file_llseek(file, offset, whence); + case SEEK_DATA: + return bch2_seek_data(file, offset); + case SEEK_HOLE: + return bch2_seek_hole(file, offset); + } + + return -EINVAL; +} + +void bch2_fs_fsio_exit(struct bch_fs *c) +{ + bioset_exit(&c->dio_write_bioset); + bioset_exit(&c->dio_read_bioset); + bioset_exit(&c->writepage_bioset); +} + +int bch2_fs_fsio_init(struct bch_fs *c) +{ + int ret = 0; + + pr_verbose_init(c->opts, ""); + + if (bioset_init(&c->writepage_bioset, + 4, offsetof(struct bch_writepage_io, op.op.wbio.bio), + BIOSET_NEED_BVECS) || + bioset_init(&c->dio_read_bioset, + 4, offsetof(struct dio_read, rbio.bio), + BIOSET_NEED_BVECS) || + bioset_init(&c->dio_write_bioset, + 4, offsetof(struct dio_write, iop.op.wbio.bio), + BIOSET_NEED_BVECS)) + ret = -ENOMEM; + + pr_verbose_init(c->opts, "ret %i", ret); + return ret; +} + +#endif /* NO_BCACHEFS_FS */ |