Adding upstream version 6.7.7.upstream/6.7.7

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1072 insertions, 0 deletions

diff --git a/fs/bcachefs/fs-io.c b/fs/bcachefs/fs-io.c
new file mode 100644
index 0000000000..fffa1743df
--- /dev/null
+++ b/fs/bcachefs/fs-io.c
@@ -0,0 +1,1072 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef NO_BCACHEFS_FS
+
+#include "bcachefs.h"
+#include "alloc_foreground.h"
+#include "bkey_buf.h"
+#include "btree_update.h"
+#include "buckets.h"
+#include "clock.h"
+#include "error.h"
+#include "extents.h"
+#include "extent_update.h"
+#include "fs.h"
+#include "fs-io.h"
+#include "fs-io-buffered.h"
+#include "fs-io-pagecache.h"
+#include "fsck.h"
+#include "inode.h"
+#include "journal.h"
+#include "io_misc.h"
+#include "keylist.h"
+#include "quota.h"
+#include "reflink.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/rmap.h>
+#include <linux/sched/signal.h>
+#include <linux/task_io_accounting_ops.h>
+#include <linux/uio.h>
+
+#include <trace/events/writeback.h>
+
+struct nocow_flush {
+	struct closure	*cl;
+	struct bch_dev	*ca;
+	struct bio	bio;
+};
+
+static void nocow_flush_endio(struct bio *_bio)
+{
+
+	struct nocow_flush *bio = container_of(_bio, struct nocow_flush, bio);
+
+	closure_put(bio->cl);
+	percpu_ref_put(&bio->ca->io_ref);
+	bio_put(&bio->bio);
+}
+
+void bch2_inode_flush_nocow_writes_async(struct bch_fs *c,
+					 struct bch_inode_info *inode,
+					 struct closure *cl)
+{
+	struct nocow_flush *bio;
+	struct bch_dev *ca;
+	struct bch_devs_mask devs;
+	unsigned dev;
+
+	dev = find_first_bit(inode->ei_devs_need_flush.d, BCH_SB_MEMBERS_MAX);
+	if (dev == BCH_SB_MEMBERS_MAX)
+		return;
+
+	devs = inode->ei_devs_need_flush;
+	memset(&inode->ei_devs_need_flush, 0, sizeof(inode->ei_devs_need_flush));
+
+	for_each_set_bit(dev, devs.d, BCH_SB_MEMBERS_MAX) {
+		rcu_read_lock();
+		ca = rcu_dereference(c->devs[dev]);
+		if (ca && !percpu_ref_tryget(&ca->io_ref))
+			ca = NULL;
+		rcu_read_unlock();
+
+		if (!ca)
+			continue;
+
+		bio = container_of(bio_alloc_bioset(ca->disk_sb.bdev, 0,
+						    REQ_OP_WRITE|REQ_PREFLUSH,
+						    GFP_KERNEL,
+						    &c->nocow_flush_bioset),
+				   struct nocow_flush, bio);
+		bio->cl			= cl;
+		bio->ca			= ca;
+		bio->bio.bi_end_io	= nocow_flush_endio;
+		closure_bio_submit(&bio->bio, cl);
+	}
+}
+
+static int bch2_inode_flush_nocow_writes(struct bch_fs *c,
+					 struct bch_inode_info *inode)
+{
+	struct closure cl;
+
+	closure_init_stack(&cl);
+	bch2_inode_flush_nocow_writes_async(c, inode, &cl);
+	closure_sync(&cl);
+
+	return 0;
+}
+
+/* i_size updates: */
+
+struct inode_new_size {
+	loff_t		new_size;
+	u64		now;
+	unsigned	fields;
+};
+
+static int inode_set_size(struct btree_trans *trans,
+			  struct bch_inode_info *inode,
+			  struct bch_inode_unpacked *bi,
+			  void *p)
+{
+	struct inode_new_size *s = p;
+
+	bi->bi_size = s->new_size;
+	if (s->fields & ATTR_ATIME)
+		bi->bi_atime = s->now;
+	if (s->fields & ATTR_MTIME)
+		bi->bi_mtime = s->now;
+	if (s->fields & ATTR_CTIME)
+		bi->bi_ctime = s->now;
+
+	return 0;
+}
+
+int __must_check bch2_write_inode_size(struct bch_fs *c,
+				       struct bch_inode_info *inode,
+				       loff_t new_size, unsigned fields)
+{
+	struct inode_new_size s = {
+		.new_size	= new_size,
+		.now		= bch2_current_time(c),
+		.fields		= fields,
+	};
+
+	return bch2_write_inode(c, inode, inode_set_size, &s, fields);
+}
+
+void __bch2_i_sectors_acct(struct bch_fs *c, struct bch_inode_info *inode,
+			   struct quota_res *quota_res, s64 sectors)
+{
+	bch2_fs_inconsistent_on((s64) inode->v.i_blocks + sectors < 0, c,
+				"inode %lu i_blocks underflow: %llu + %lli < 0 (ondisk %lli)",
+				inode->v.i_ino, (u64) inode->v.i_blocks, sectors,
+				inode->ei_inode.bi_sectors);
+	inode->v.i_blocks += sectors;
+
+#ifdef CONFIG_BCACHEFS_QUOTA
+	if (quota_res &&
+	    !test_bit(EI_INODE_SNAPSHOT, &inode->ei_flags) &&
+	    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, KEY_TYPE_QUOTA_WARN);
+	}
+#endif
+}
+
+/* fsync: */
+
+/*
+ * inode->ei_inode.bi_journal_seq won't be up to date since it's set in an
+ * insert trigger: look up the btree inode instead
+ */
+static int bch2_flush_inode(struct bch_fs *c,
+			    struct bch_inode_info *inode)
+{
+	struct bch_inode_unpacked u;
+	int ret;
+
+	if (c->opts.journal_flush_disabled)
+		return 0;
+
+	ret = bch2_inode_find_by_inum(c, inode_inum(inode), &u);
+	if (ret)
+		return ret;
+
+	return bch2_journal_flush_seq(&c->journal, u.bi_journal_seq) ?:
+		bch2_inode_flush_nocow_writes(c, inode);
+}
+
+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, ret2, ret3;
+
+	ret = file_write_and_wait_range(file, start, end);
+	ret2 = sync_inode_metadata(&inode->v, 1);
+	ret3 = bch2_flush_inode(c, inode);
+
+	return bch2_err_class(ret ?: ret2 ?: ret3);
+}
+
+/* truncate: */
+
+static inline int range_has_data(struct bch_fs *c, u32 subvol,
+				 struct bpos start,
+				 struct bpos end)
+{
+	struct btree_trans *trans = bch2_trans_get(c);
+	struct btree_iter iter;
+	struct bkey_s_c k;
+	int ret = 0;
+retry:
+	bch2_trans_begin(trans);
+
+	ret = bch2_subvolume_get_snapshot(trans, subvol, &start.snapshot);
+	if (ret)
+		goto err;
+
+	for_each_btree_key_upto_norestart(trans, iter, BTREE_ID_extents, start, end, 0, k, ret)
+		if (bkey_extent_is_data(k.k) && !bkey_extent_is_unwritten(k)) {
+			ret = 1;
+			break;
+		}
+	start = iter.pos;
+	bch2_trans_iter_exit(trans, &iter);
+err:
+	if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+		goto retry;
+
+	bch2_trans_put(trans);
+	return ret;
+}
+
+static int __bch2_truncate_folio(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;
+	struct bch_folio *s;
+	unsigned start_offset;
+	unsigned end_offset;
+	unsigned i;
+	struct folio *folio;
+	s64 i_sectors_delta = 0;
+	int ret = 0;
+	u64 end_pos;
+
+	folio = filemap_lock_folio(mapping, index);
+	if (IS_ERR_OR_NULL(folio)) {
+		/*
+		 * XXX: we're doing two index lookups when we end up reading the
+		 * folio
+		 */
+		ret = range_has_data(c, inode->ei_subvol,
+				POS(inode->v.i_ino, (index << PAGE_SECTORS_SHIFT)),
+				POS(inode->v.i_ino, (index << PAGE_SECTORS_SHIFT) + PAGE_SECTORS));
+		if (ret <= 0)
+			return ret;
+
+		folio = __filemap_get_folio(mapping, index,
+					    FGP_LOCK|FGP_CREAT, GFP_KERNEL);
+		if (IS_ERR_OR_NULL(folio)) {
+			ret = -ENOMEM;
+			goto out;
+		}
+	}
+
+	BUG_ON(start	>= folio_end_pos(folio));
+	BUG_ON(end	<= folio_pos(folio));
+
+	start_offset	= max(start, folio_pos(folio)) - folio_pos(folio);
+	end_offset	= min_t(u64, end, folio_end_pos(folio)) - folio_pos(folio);
+
+	/* Folio boundary? Nothing to do */
+	if (start_offset == 0 &&
+	    end_offset == folio_size(folio)) {
+		ret = 0;
+		goto unlock;
+	}
+
+	s = bch2_folio_create(folio, 0);
+	if (!s) {
+		ret = -ENOMEM;
+		goto unlock;
+	}
+
+	if (!folio_test_uptodate(folio)) {
+		ret = bch2_read_single_folio(folio, mapping);
+		if (ret)
+			goto unlock;
+	}
+
+	ret = bch2_folio_set(c, inode_inum(inode), &folio, 1);
+	if (ret)
+		goto unlock;
+
+	for (i = round_up(start_offset, block_bytes(c)) >> 9;
+	     i < round_down(end_offset, block_bytes(c)) >> 9;
+	     i++) {
+		s->s[i].nr_replicas	= 0;
+
+		i_sectors_delta -= s->s[i].state == SECTOR_dirty;
+		bch2_folio_sector_set(folio, s, i, SECTOR_unallocated);
+	}
+
+	bch2_i_sectors_acct(c, inode, NULL, i_sectors_delta);
+
+	/*
+	 * Caller needs to know whether this folio will be written out by
+	 * writeback - doing an i_size update if necessary - or whether it will
+	 * be responsible for the i_size update.
+	 *
+	 * Note that we shouldn't ever see a folio beyond EOF, but check and
+	 * warn if so. This has been observed by failure to clean up folios
+	 * after a short write and there's still a chance reclaim will fix
+	 * things up.
+	 */
+	WARN_ON_ONCE(folio_pos(folio) >= inode->v.i_size);
+	end_pos = folio_end_pos(folio);
+	if (inode->v.i_size > folio_pos(folio))
+		end_pos = min_t(u64, inode->v.i_size, end_pos);
+	ret = s->s[folio_pos_to_s(folio, end_pos - 1)].state >= SECTOR_dirty;
+
+	folio_zero_segment(folio, start_offset, end_offset);
+
+	/*
+	 * Bit of a hack - we don't want truncate to fail due to -ENOSPC.
+	 *
+	 * XXX: because we aren't currently tracking whether the folio has actual
+	 * data in it (vs. just 0s, or only partially written) this wrong. ick.
+	 */
+	BUG_ON(bch2_get_folio_disk_reservation(c, inode, folio, false));
+
+	/*
+	 * This removes any writeable userspace mappings; we need to force
+	 * .page_mkwrite to be called again before any mmapped writes, to
+	 * redirty the full page:
+	 */
+	folio_mkclean(folio);
+	filemap_dirty_folio(mapping, folio);
+unlock:
+	folio_unlock(folio);
+	folio_put(folio);
+out:
+	return ret;
+}
+
+static int bch2_truncate_folio(struct bch_inode_info *inode, loff_t from)
+{
+	return __bch2_truncate_folio(inode, from >> PAGE_SHIFT,
+				     from, ANYSINT_MAX(loff_t));
+}
+
+static int bch2_truncate_folios(struct bch_inode_info *inode,
+				loff_t start, loff_t end)
+{
+	int ret = __bch2_truncate_folio(inode, start >> PAGE_SHIFT,
+					start, end);
+
+	if (ret >= 0 &&
+	    start >> PAGE_SHIFT != end >> PAGE_SHIFT)
+		ret = __bch2_truncate_folio(inode,
+					(end - 1) >> PAGE_SHIFT,
+					start, end);
+	return ret;
+}
+
+static int bch2_extend(struct mnt_idmap *idmap,
+		       struct bch_inode_info *inode,
+		       struct bch_inode_unpacked *inode_u,
+		       struct iattr *iattr)
+{
+	struct address_space *mapping = inode->v.i_mapping;
+	int ret;
+
+	/*
+	 * sync appends:
+	 *
+	 * this has to be done _before_ extending i_size:
+	 */
+	ret = filemap_write_and_wait_range(mapping, inode_u->bi_size, S64_MAX);
+	if (ret)
+		return ret;
+
+	truncate_setsize(&inode->v, iattr->ia_size);
+
+	return bch2_setattr_nonsize(idmap, inode, iattr);
+}
+
+int bchfs_truncate(struct mnt_idmap *idmap,
+		  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 bch_inode_unpacked inode_u;
+	s64 i_sectors_delta = 0;
+	int ret = 0;
+
+	/*
+	 * If the truncate call with change the size of the file, the
+	 * cmtimes should be updated. If the size will not change, we
+	 * do not need to update the cmtimes.
+	 */
+	if (iattr->ia_size != inode->v.i_size) {
+		if (!(iattr->ia_valid & ATTR_MTIME))
+			ktime_get_coarse_real_ts64(&iattr->ia_mtime);
+		if (!(iattr->ia_valid & ATTR_CTIME))
+			ktime_get_coarse_real_ts64(&iattr->ia_ctime);
+		iattr->ia_valid |= ATTR_MTIME|ATTR_CTIME;
+	}
+
+	inode_dio_wait(&inode->v);
+	bch2_pagecache_block_get(inode);
+
+	ret = bch2_inode_find_by_inum(c, inode_inum(inode), &inode_u);
+	if (ret)
+		goto err;
+
+	/*
+	 * check this before next assertion; on filesystem error our normal
+	 * invariants are a bit broken (truncate has to truncate the page cache
+	 * before the inode).
+	 */
+	ret = bch2_journal_error(&c->journal);
+	if (ret)
+		goto err;
+
+	WARN_ONCE(!test_bit(EI_INODE_ERROR, &inode->ei_flags) &&
+		  inode->v.i_size < inode_u.bi_size,
+		  "truncate spotted in mem i_size < btree i_size: %llu < %llu\n",
+		  (u64) inode->v.i_size, inode_u.bi_size);
+
+	if (iattr->ia_size > inode->v.i_size) {
+		ret = bch2_extend(idmap, inode, &inode_u, iattr);
+		goto err;
+	}
+
+	iattr->ia_valid &= ~ATTR_SIZE;
+
+	ret = bch2_truncate_folio(inode, iattr->ia_size);
+	if (unlikely(ret < 0))
+		goto err;
+
+	truncate_setsize(&inode->v, iattr->ia_size);
+
+	/*
+	 * When extending, we're going to write the new i_size to disk
+	 * immediately so we need to flush anything above the current on disk
+	 * i_size first:
+	 *
+	 * Also, when extending we need to flush the page that i_size currently
+	 * straddles - if it's mapped to userspace, we need to ensure that
+	 * userspace has to redirty it and call .mkwrite -> set_page_dirty
+	 * again to allocate the part of the page that was extended.
+	 */
+	if (iattr->ia_size > inode_u.bi_size)
+		ret = filemap_write_and_wait_range(mapping,
+				inode_u.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;
+
+	ret = bch2_truncate(c, inode_inum(inode), iattr->ia_size, &i_sectors_delta);
+	bch2_i_sectors_acct(c, inode, NULL, i_sectors_delta);
+
+	if (unlikely(ret)) {
+		/*
+		 * If we error here, VFS caches are now inconsistent with btree
+		 */
+		set_bit(EI_INODE_ERROR, &inode->ei_flags);
+		goto err;
+	}
+
+	bch2_fs_inconsistent_on(!inode->v.i_size && inode->v.i_blocks &&
+				!bch2_journal_error(&c->journal), c,
+				"inode %lu truncated to 0 but i_blocks %llu (ondisk %lli)",
+				inode->v.i_ino, (u64) inode->v.i_blocks,
+				inode->ei_inode.bi_sectors);
+
+	ret = bch2_setattr_nonsize(idmap, inode, iattr);
+err:
+	bch2_pagecache_block_put(inode);
+	return bch2_err_class(ret);
+}
+
+/* fallocate: */
+
+static int inode_update_times_fn(struct btree_trans *trans,
+				 struct bch_inode_info *inode,
+				 struct bch_inode_unpacked *bi, void *p)
+{
+	struct bch_fs *c = inode->v.i_sb->s_fs_info;
+
+	bi->bi_mtime = bi->bi_ctime = bch2_current_time(c);
+	return 0;
+}
+
+static long bchfs_fpunch(struct bch_inode_info *inode, loff_t offset, loff_t len)
+{
+	struct bch_fs *c = inode->v.i_sb->s_fs_info;
+	u64 end		= offset + len;
+	u64 block_start	= round_up(offset, block_bytes(c));
+	u64 block_end	= round_down(end, block_bytes(c));
+	bool truncated_last_page;
+	int ret = 0;
+
+	ret = bch2_truncate_folios(inode, offset, end);
+	if (unlikely(ret < 0))
+		goto err;
+
+	truncated_last_page = ret;
+
+	truncate_pagecache_range(&inode->v, offset, end - 1);
+
+	if (block_start < block_end) {
+		s64 i_sectors_delta = 0;
+
+		ret = bch2_fpunch(c, inode_inum(inode),
+				  block_start >> 9, block_end >> 9,
+				  &i_sectors_delta);
+		bch2_i_sectors_acct(c, inode, NULL, i_sectors_delta);
+	}
+
+	mutex_lock(&inode->ei_update_lock);
+	if (end >= inode->v.i_size && !truncated_last_page) {
+		ret = bch2_write_inode_size(c, inode, inode->v.i_size,
+					    ATTR_MTIME|ATTR_CTIME);
+	} else {
+		ret = bch2_write_inode(c, inode, inode_update_times_fn, NULL,
+				       ATTR_MTIME|ATTR_CTIME);
+	}
+	mutex_unlock(&inode->ei_update_lock);
+err:
+	return ret;
+}
+
+static long bchfs_fcollapse_finsert(struct bch_inode_info *inode,
+				   loff_t offset, loff_t len,
+				   bool insert)
+{
+	struct bch_fs *c = inode->v.i_sb->s_fs_info;
+	struct address_space *mapping = inode->v.i_mapping;
+	s64 i_sectors_delta = 0;
+	int ret = 0;
+
+	if ((offset | len) & (block_bytes(c) - 1))
+		return -EINVAL;
+
+	if (insert) {
+		if (offset >= inode->v.i_size)
+			return -EINVAL;
+	} else {
+		if (offset + len >= inode->v.i_size)
+			return -EINVAL;
+	}
+
+	ret = bch2_write_invalidate_inode_pages_range(mapping, offset, LLONG_MAX);
+	if (ret)
+		return ret;
+
+	if (insert)
+		i_size_write(&inode->v, inode->v.i_size + len);
+
+	ret = bch2_fcollapse_finsert(c, inode_inum(inode), offset >> 9, len >> 9,
+				     insert, &i_sectors_delta);
+	if (!ret && !insert)
+		i_size_write(&inode->v, inode->v.i_size - len);
+	bch2_i_sectors_acct(c, inode, NULL, i_sectors_delta);
+
+	return ret;
+}
+
+static int __bchfs_fallocate(struct bch_inode_info *inode, int mode,
+			     u64 start_sector, u64 end_sector)
+{
+	struct bch_fs *c = inode->v.i_sb->s_fs_info;
+	struct btree_trans *trans = bch2_trans_get(c);
+	struct btree_iter iter;
+	struct bpos end_pos = POS(inode->v.i_ino, end_sector);
+	struct bch_io_opts opts;
+	int ret = 0;
+
+	bch2_inode_opts_get(&opts, c, &inode->ei_inode);
+
+	bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
+			POS(inode->v.i_ino, start_sector),
+			BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
+
+	while (!ret && bkey_lt(iter.pos, end_pos)) {
+		s64 i_sectors_delta = 0;
+		struct quota_res quota_res = { 0 };
+		struct bkey_s_c k;
+		unsigned sectors;
+		bool is_allocation;
+		u64 hole_start, hole_end;
+		u32 snapshot;
+
+		bch2_trans_begin(trans);
+
+		ret = bch2_subvolume_get_snapshot(trans,
+					inode->ei_subvol, &snapshot);
+		if (ret)
+			goto bkey_err;
+
+		bch2_btree_iter_set_snapshot(&iter, snapshot);
+
+		k = bch2_btree_iter_peek_slot(&iter);
+		if ((ret = bkey_err(k)))
+			goto bkey_err;
+
+		hole_start	= iter.pos.offset;
+		hole_end	= bpos_min(k.k->p, end_pos).offset;
+		is_allocation	= bkey_extent_is_allocation(k.k);
+
+		/* already reserved */
+		if (bkey_extent_is_reservation(k) &&
+		    bch2_bkey_nr_ptrs_fully_allocated(k) >= opts.data_replicas) {
+			bch2_btree_iter_advance(&iter);
+			continue;
+		}
+
+		if (bkey_extent_is_data(k.k) &&
+		    !(mode & FALLOC_FL_ZERO_RANGE)) {
+			bch2_btree_iter_advance(&iter);
+			continue;
+		}
+
+		if (!(mode & FALLOC_FL_ZERO_RANGE)) {
+			/*
+			 * Lock ordering - can't be holding btree locks while
+			 * blocking on a folio lock:
+			 */
+			if (bch2_clamp_data_hole(&inode->v,
+						 &hole_start,
+						 &hole_end,
+						 opts.data_replicas, true))
+				ret = drop_locks_do(trans,
+					(bch2_clamp_data_hole(&inode->v,
+							      &hole_start,
+							      &hole_end,
+							      opts.data_replicas, false), 0));
+			bch2_btree_iter_set_pos(&iter, POS(iter.pos.inode, hole_start));
+
+			if (ret)
+				goto bkey_err;
+
+			if (hole_start == hole_end)
+				continue;
+		}
+
+		sectors	= hole_end - hole_start;
+
+		if (!is_allocation) {
+			ret = bch2_quota_reservation_add(c, inode,
+					&quota_res, sectors, true);
+			if (unlikely(ret))
+				goto bkey_err;
+		}
+
+		ret = bch2_extent_fallocate(trans, inode_inum(inode), &iter,
+					    sectors, opts, &i_sectors_delta,
+					    writepoint_hashed((unsigned long) current));
+		if (ret)
+			goto bkey_err;
+
+		bch2_i_sectors_acct(c, inode, &quota_res, i_sectors_delta);
+
+		drop_locks_do(trans,
+			(bch2_mark_pagecache_reserved(inode, hole_start, iter.pos.offset), 0));
+bkey_err:
+		bch2_quota_reservation_put(c, inode, &quota_res);
+		if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+			ret = 0;
+	}
+
+	if (bch2_err_matches(ret, ENOSPC) && (mode & FALLOC_FL_ZERO_RANGE)) {
+		struct quota_res quota_res = { 0 };
+		s64 i_sectors_delta = 0;
+
+		bch2_fpunch_at(trans, &iter, inode_inum(inode),
+			       end_sector, &i_sectors_delta);
+		bch2_i_sectors_acct(c, inode, &quota_res, i_sectors_delta);
+		bch2_quota_reservation_put(c, inode, &quota_res);
+	}
+
+	bch2_trans_iter_exit(trans, &iter);
+	bch2_trans_put(trans);
+	return ret;
+}
+
+static long bchfs_fallocate(struct bch_inode_info *inode, int mode,
+			    loff_t offset, loff_t len)
+{
+	struct bch_fs *c = inode->v.i_sb->s_fs_info;
+	u64 end		= offset + len;
+	u64 block_start	= round_down(offset,	block_bytes(c));
+	u64 block_end	= round_up(end,		block_bytes(c));
+	bool truncated_last_page = false;
+	int ret, ret2 = 0;
+
+	if (!(mode & FALLOC_FL_KEEP_SIZE) && end > inode->v.i_size) {
+		ret = inode_newsize_ok(&inode->v, end);
+		if (ret)
+			return ret;
+	}
+
+	if (mode & FALLOC_FL_ZERO_RANGE) {
+		ret = bch2_truncate_folios(inode, offset, end);
+		if (unlikely(ret < 0))
+			return ret;
+
+		truncated_last_page = ret;
+
+		truncate_pagecache_range(&inode->v, offset, end - 1);
+
+		block_start	= round_up(offset,	block_bytes(c));
+		block_end	= round_down(end,	block_bytes(c));
+	}
+
+	ret = __bchfs_fallocate(inode, mode, block_start >> 9, block_end >> 9);
+
+	/*
+	 * On -ENOSPC in ZERO_RANGE mode, we still want to do the inode update,
+	 * so that the VFS cache i_size is consistent with the btree i_size:
+	 */
+	if (ret &&
+	    !(bch2_err_matches(ret, ENOSPC) && (mode & FALLOC_FL_ZERO_RANGE)))
+		return ret;
+
+	if (mode & FALLOC_FL_KEEP_SIZE && end > inode->v.i_size)
+		end = inode->v.i_size;
+
+	if (end >= inode->v.i_size &&
+	    (((mode & FALLOC_FL_ZERO_RANGE) && !truncated_last_page) ||
+	     !(mode & FALLOC_FL_KEEP_SIZE))) {
+		spin_lock(&inode->v.i_lock);
+		i_size_write(&inode->v, end);
+		spin_unlock(&inode->v.i_lock);
+
+		mutex_lock(&inode->ei_update_lock);
+		ret2 = bch2_write_inode_size(c, inode, end, 0);
+		mutex_unlock(&inode->ei_update_lock);
+	}
+
+	return ret ?: ret2;
+}
+
+long bch2_fallocate_dispatch(struct file *file, int mode,
+			     loff_t offset, loff_t len)
+{
+	struct bch_inode_info *inode = file_bch_inode(file);
+	struct bch_fs *c = inode->v.i_sb->s_fs_info;
+	long ret;
+
+	if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_fallocate))
+		return -EROFS;
+
+	inode_lock(&inode->v);
+	inode_dio_wait(&inode->v);
+	bch2_pagecache_block_get(inode);
+
+	ret = file_modified(file);
+	if (ret)
+		goto err;
+
+	if (!(mode & ~(FALLOC_FL_KEEP_SIZE|FALLOC_FL_ZERO_RANGE)))
+		ret = bchfs_fallocate(inode, mode, offset, len);
+	else if (mode == (FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE))
+		ret = bchfs_fpunch(inode, offset, len);
+	else if (mode == FALLOC_FL_INSERT_RANGE)
+		ret = bchfs_fcollapse_finsert(inode, offset, len, true);
+	else if (mode == FALLOC_FL_COLLAPSE_RANGE)
+		ret = bchfs_fcollapse_finsert(inode, offset, len, false);
+	else
+		ret = -EOPNOTSUPP;
+err:
+	bch2_pagecache_block_put(inode);
+	inode_unlock(&inode->v);
+	bch2_write_ref_put(c, BCH_WRITE_REF_fallocate);
+
+	return bch2_err_class(ret);
+}
+
+/*
+ * Take a quota reservation for unallocated blocks in a given file range
+ * Does not check pagecache
+ */
+static int quota_reserve_range(struct bch_inode_info *inode,
+			       struct quota_res *res,
+			       u64 start, u64 end)
+{
+	struct bch_fs *c = inode->v.i_sb->s_fs_info;
+	struct btree_trans *trans = bch2_trans_get(c);
+	struct btree_iter iter;
+	struct bkey_s_c k;
+	u32 snapshot;
+	u64 sectors = end - start;
+	u64 pos = start;
+	int ret;
+retry:
+	bch2_trans_begin(trans);
+
+	ret = bch2_subvolume_get_snapshot(trans, inode->ei_subvol, &snapshot);
+	if (ret)
+		goto err;
+
+	bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
+			     SPOS(inode->v.i_ino, pos, snapshot), 0);
+
+	while (!(ret = btree_trans_too_many_iters(trans)) &&
+	       (k = bch2_btree_iter_peek_upto(&iter, POS(inode->v.i_ino, end - 1))).k &&
+	       !(ret = bkey_err(k))) {
+		if (bkey_extent_is_allocation(k.k)) {
+			u64 s = min(end, k.k->p.offset) -
+				max(start, bkey_start_offset(k.k));
+			BUG_ON(s > sectors);
+			sectors -= s;
+		}
+		bch2_btree_iter_advance(&iter);
+	}
+	pos = iter.pos.offset;
+	bch2_trans_iter_exit(trans, &iter);
+err:
+	if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+		goto retry;
+
+	bch2_trans_put(trans);
+
+	return ret ?: bch2_quota_reservation_add(c, inode, res, sectors, true);
+}
+
+loff_t bch2_remap_file_range(struct file *file_src, loff_t pos_src,
+			     struct file *file_dst, loff_t pos_dst,
+			     loff_t len, unsigned remap_flags)
+{
+	struct bch_inode_info *src = file_bch_inode(file_src);
+	struct bch_inode_info *dst = file_bch_inode(file_dst);
+	struct bch_fs *c = src->v.i_sb->s_fs_info;
+	struct quota_res quota_res = { 0 };
+	s64 i_sectors_delta = 0;
+	u64 aligned_len;
+	loff_t ret = 0;
+
+	if (remap_flags & ~(REMAP_FILE_DEDUP|REMAP_FILE_ADVISORY))
+		return -EINVAL;
+
+	if (remap_flags & REMAP_FILE_DEDUP)
+		return -EOPNOTSUPP;
+
+	if ((pos_src & (block_bytes(c) - 1)) ||
+	    (pos_dst & (block_bytes(c) - 1)))
+		return -EINVAL;
+
+	if (src == dst &&
+	    abs(pos_src - pos_dst) < len)
+		return -EINVAL;
+
+	bch2_lock_inodes(INODE_LOCK|INODE_PAGECACHE_BLOCK, src, dst);
+
+	inode_dio_wait(&src->v);
+	inode_dio_wait(&dst->v);
+
+	ret = generic_remap_file_range_prep(file_src, pos_src,
+					    file_dst, pos_dst,
+					    &len, remap_flags);
+	if (ret < 0 || len == 0)
+		goto err;
+
+	aligned_len = round_up((u64) len, block_bytes(c));
+
+	ret = bch2_write_invalidate_inode_pages_range(dst->v.i_mapping,
+				pos_dst, pos_dst + len - 1);
+	if (ret)
+		goto err;
+
+	ret = quota_reserve_range(dst, &quota_res, pos_dst >> 9,
+				  (pos_dst + aligned_len) >> 9);
+	if (ret)
+		goto err;
+
+	file_update_time(file_dst);
+
+	bch2_mark_pagecache_unallocated(src, pos_src >> 9,
+				   (pos_src + aligned_len) >> 9);
+
+	ret = bch2_remap_range(c,
+			       inode_inum(dst), pos_dst >> 9,
+			       inode_inum(src), pos_src >> 9,
+			       aligned_len >> 9,
+			       pos_dst + len, &i_sectors_delta);
+	if (ret < 0)
+		goto err;
+
+	/*
+	 * due to alignment, we might have remapped slightly more than requsted
+	 */
+	ret = min((u64) ret << 9, (u64) len);
+
+	bch2_i_sectors_acct(c, dst, &quota_res, i_sectors_delta);
+
+	spin_lock(&dst->v.i_lock);
+	if (pos_dst + ret > dst->v.i_size)
+		i_size_write(&dst->v, pos_dst + ret);
+	spin_unlock(&dst->v.i_lock);
+
+	if ((file_dst->f_flags & (__O_SYNC | O_DSYNC)) ||
+	    IS_SYNC(file_inode(file_dst)))
+		ret = bch2_flush_inode(c, dst);
+err:
+	bch2_quota_reservation_put(c, dst, &quota_res);
+	bch2_unlock_inodes(INODE_LOCK|INODE_PAGECACHE_BLOCK, src, dst);
+
+	return bch2_err_class(ret);
+}
+
+/* fseek: */
+
+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_trans *trans;
+	struct btree_iter iter;
+	struct bkey_s_c k;
+	subvol_inum inum = inode_inum(inode);
+	u64 isize, next_data = MAX_LFS_FILESIZE;
+	u32 snapshot;
+	int ret;
+
+	isize = i_size_read(&inode->v);
+	if (offset >= isize)
+		return -ENXIO;
+
+	trans = bch2_trans_get(c);
+retry:
+	bch2_trans_begin(trans);
+
+	ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
+	if (ret)
+		goto err;
+
+	for_each_btree_key_upto_norestart(trans, iter, BTREE_ID_extents,
+			   SPOS(inode->v.i_ino, offset >> 9, snapshot),
+			   POS(inode->v.i_ino, U64_MAX),
+			   0, k, ret) {
+		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;
+	}
+	bch2_trans_iter_exit(trans, &iter);
+err:
+	if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+		goto retry;
+
+	bch2_trans_put(trans);
+	if (ret)
+		return ret;
+
+	if (next_data > offset)
+		next_data = bch2_seek_pagecache_data(&inode->v,
+					offset, next_data, 0, false);
+
+	if (next_data >= isize)
+		return -ENXIO;
+
+	return vfs_setpos(file, next_data, MAX_LFS_FILESIZE);
+}
+
+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_trans *trans;
+	struct btree_iter iter;
+	struct bkey_s_c k;
+	subvol_inum inum = inode_inum(inode);
+	u64 isize, next_hole = MAX_LFS_FILESIZE;
+	u32 snapshot;
+	int ret;
+
+	isize = i_size_read(&inode->v);
+	if (offset >= isize)
+		return -ENXIO;
+
+	trans = bch2_trans_get(c);
+retry:
+	bch2_trans_begin(trans);
+
+	ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
+	if (ret)
+		goto err;
+
+	for_each_btree_key_norestart(trans, iter, BTREE_ID_extents,
+			   SPOS(inode->v.i_ino, offset >> 9, snapshot),
+			   BTREE_ITER_SLOTS, k, ret) {
+		if (k.k->p.inode != inode->v.i_ino) {
+			next_hole = bch2_seek_pagecache_hole(&inode->v,
+					offset, MAX_LFS_FILESIZE, 0, false);
+			break;
+		} else if (!bkey_extent_is_data(k.k)) {
+			next_hole = bch2_seek_pagecache_hole(&inode->v,
+					max(offset, bkey_start_offset(k.k) << 9),
+					k.k->p.offset << 9, 0, false);
+
+			if (next_hole < k.k->p.offset << 9)
+				break;
+		} else {
+			offset = max(offset, bkey_start_offset(k.k) << 9);
+		}
+	}
+	bch2_trans_iter_exit(trans, &iter);
+err:
+	if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+		goto retry;
+
+	bch2_trans_put(trans);
+	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)
+{
+	loff_t ret;
+
+	switch (whence) {
+	case SEEK_SET:
+	case SEEK_CUR:
+	case SEEK_END:
+		ret = generic_file_llseek(file, offset, whence);
+		break;
+	case SEEK_DATA:
+		ret = bch2_seek_data(file, offset);
+		break;
+	case SEEK_HOLE:
+		ret = bch2_seek_hole(file, offset);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	return bch2_err_class(ret);
+}
+
+void bch2_fs_fsio_exit(struct bch_fs *c)
+{
+	bioset_exit(&c->nocow_flush_bioset);
+}
+
+int bch2_fs_fsio_init(struct bch_fs *c)
+{
+	if (bioset_init(&c->nocow_flush_bioset,
+			1, offsetof(struct nocow_flush, bio), 0))
+		return -BCH_ERR_ENOMEM_nocow_flush_bioset_init;
+
+	return 0;
+}
+
+#endif /* NO_BCACHEFS_FS */