Merge branch 'vfs-6.15.iomap' of...

   * **IOMAP_F_PRIVATE**: Starting with this value, the upper bits can

     be set by the filesystem for its own purposes.

   * **IOMAP_F_ANON_WRITE**: Indicates that (write) I/O does not have a target

     block assigned to it yet and the file system will do that in the bio

     submission handler, splitting the I/O as needed.

   These flags can be set by iomap itself during file operations.

   The filesystem should supply an ``->iomap_end`` function if it needs

   to observe these flags:

   ``IOMAP_NOWAIT`` is often set on behalf of ``IOCB_NOWAIT`` or

   ``RWF_NOWAIT``.

 * ``IOMAP_DONTCACHE`` is set when the caller wishes to perform a

   buffered file I/O and would like the kernel to drop the pagecache

   after the I/O completes, if it isn't already being used by another

   thread.

If it is necessary to read existing file contents from a `different

<https://lore.kernel.org/all/20191008071527.29304-9-hch@lst.de/>`_

device or address range on a device, the filesystem should return that

 * ``IOCB_NOWAIT``: Turns on ``IOMAP_NOWAIT``.

 * ``IOCB_DONTCACHE``: Turns on ``IOMAP_DONTCACHE``.

Internal per-Folio State

------------------------

 struct iomap_writeback_ops {

     int (*map_blocks)(struct iomap_writepage_ctx *wpc, struct inode *inode,

                       loff_t offset, unsigned len);

     int (*prepare_ioend)(struct iomap_ioend *ioend, int status);

     int (*submit_ioend)(struct iomap_writepage_ctx *wpc, int status);

     void (*discard_folio)(struct folio *folio, loff_t pos);

 };

    purpose.

    This function must be supplied by the filesystem.

  - ``prepare_ioend``: Enables filesystems to transform the writeback

    ioend or perform any other preparatory work before the writeback I/O

    is submitted.

  - ``submit_ioend``: Allows the file systems to hook into writeback bio

    submission.

    This might include pre-write space accounting updates, or installing

    a custom ``->bi_end_io`` function for internal purposes, such as

    deferring the ioend completion to a workqueue to run metadata update

    transactions from process context.

    transactions from process context before submitting the bio.

    This function is optional.

  - ``discard_folio``: iomap calls this function after ``->map_blocks``

storage device.

Filesystems that need to update internal bookkeeping (e.g. unwritten

extent conversions) should provide a ``->prepare_ioend`` function to

extent conversions) should provide a ``->submit_ioend`` function to

set ``struct iomap_end::bio::bi_end_io`` to its own function.

This function should call ``iomap_finish_ioends`` after finishing its

own work (e.g. unwritten extent conversion).

   if the mapping is unwritten and the filesystem cannot handle zeroing

   the unaligned regions without exposing stale contents.

 * ``IOMAP_ATOMIC``: This write is being issued with torn-write

   protection.

 * ``IOMAP_ATOMIC_HW``: This write is being issued with torn-write

   protection based on HW-offload support.

   Only a single bio can be created for the write, and the write must

   not be split into multiple I/O requests, i.e. flag REQ_ATOMIC must be

   set.

   conversion or copy on write), all updates for the entire file range

   must be committed atomically as well.

   Only one space mapping is allowed per untorn write.

   Untorn writes must be aligned to, and must not be longer than, a

   single file block.

   Untorn writes may be longer than a single file block. In all cases,

   the mapping start disk block must have at least the same alignment as

   the write offset.

 * ``IOMAP_ATOMIC_SW``: This write is being issued with torn-write

   protection via a software mechanism provided by the filesystem.

   All the disk block alignment and single bio restrictions which apply

   to IOMAP_ATOMIC_HW do not apply here.

   SW-based untorn writes would typically be used as a fallback when

   HW-based untorn writes may not be issued, e.g. the range of the write

   covers multiple extents, meaning that it is not possible to issue

   a single bio.

   All filesystem metadata updates for the entire file range must be

   committed atomically as well.

Callers commonly hold ``i_rwsem`` in shared or exclusive mode before

calling this function.

}

#endif /* CONFIG_FS_DAX_PMD */

static s64 dax_unshare_iter(struct iomap_iter *iter)

static int dax_unshare_iter(struct iomap_iter *iter)

{

	struct iomap *iomap = &iter->iomap;

	const struct iomap *srcmap = iomap_iter_srcmap(iter);

	u64 copy_len = iomap_length(iter);

	u32 mod;

	int id = 0;

	s64 ret = 0;

	s64 ret;

	void *daddr = NULL, *saddr = NULL;

	if (!iomap_want_unshare_iter(iter))

		return iomap_length(iter);

		return iomap_iter_advance_full(iter);

	/*

	 * Extend the file range to be aligned to fsblock/pagesize, because

	if (ret < 0)

		goto out_unlock;

	if (copy_mc_to_kernel(daddr, saddr, copy_len) == 0)

		ret = iomap_length(iter);

	else

	if (copy_mc_to_kernel(daddr, saddr, copy_len) != 0)

		ret = -EIO;

out_unlock:

	dax_read_unlock(id);

	if (ret < 0)

		return dax_mem2blk_err(ret);

	return iomap_iter_advance_full(iter);

}

int dax_file_unshare(struct inode *inode, loff_t pos, loff_t len,

	iter.len = min(len, size - pos);

	while ((ret = iomap_iter(&iter, ops)) > 0)

		iter.processed = dax_unshare_iter(&iter);

		iter.status = dax_unshare_iter(&iter);

	return ret;

}

EXPORT_SYMBOL_GPL(dax_file_unshare);

	return ret;

}

static s64 dax_zero_iter(struct iomap_iter *iter, bool *did_zero)

static int dax_zero_iter(struct iomap_iter *iter, bool *did_zero)

{

	const struct iomap *iomap = &iter->iomap;

	const struct iomap *srcmap = iomap_iter_srcmap(iter);

	loff_t pos = iter->pos;

	u64 length = iomap_length(iter);

	s64 written = 0;

	int ret;

	/* already zeroed?  we're done. */

	if (srcmap->type == IOMAP_HOLE || srcmap->type == IOMAP_UNWRITTEN)

		return length;

		return iomap_iter_advance(iter, &length);

	/*

	 * invalidate the pages whose sharing state is to be changed

	 */

	if (iomap->flags & IOMAP_F_SHARED)

		invalidate_inode_pages2_range(iter->inode->i_mapping,

					      pos >> PAGE_SHIFT,

					      (pos + length - 1) >> PAGE_SHIFT);

				iter->pos >> PAGE_SHIFT,

				(iter->pos + length - 1) >> PAGE_SHIFT);

	do {

		loff_t pos = iter->pos;

		unsigned offset = offset_in_page(pos);

		unsigned size = min_t(u64, PAGE_SIZE - offset, length);

		pgoff_t pgoff = dax_iomap_pgoff(iomap, pos);

		long rc;

		int id;

		length = min_t(u64, PAGE_SIZE - offset, length);

		id = dax_read_lock();

		if (IS_ALIGNED(pos, PAGE_SIZE) && size == PAGE_SIZE)

			rc = dax_zero_page_range(iomap->dax_dev, pgoff, 1);

		if (IS_ALIGNED(pos, PAGE_SIZE) && length == PAGE_SIZE)

			ret = dax_zero_page_range(iomap->dax_dev, pgoff, 1);

		else

			rc = dax_memzero(iter, pos, size);

			ret = dax_memzero(iter, pos, length);

		dax_read_unlock(id);

		if (rc < 0)

			return rc;

		pos += size;

		length -= size;

		written += size;

		if (ret < 0)

			return ret;

		ret = iomap_iter_advance(iter, &length);

		if (ret)

			return ret;

	} while (length > 0);

	if (did_zero)

		*did_zero = true;

	return written;

	return ret;

}

int dax_zero_range(struct inode *inode, loff_t pos, loff_t len, bool *did_zero,

	int ret;

	while ((ret = iomap_iter(&iter, ops)) > 0)

		iter.processed = dax_zero_iter(&iter, did_zero);

		iter.status = dax_zero_iter(&iter, did_zero);

	return ret;

}

EXPORT_SYMBOL_GPL(dax_zero_range);

}

EXPORT_SYMBOL_GPL(dax_truncate_page);

static loff_t dax_iomap_iter(const struct iomap_iter *iomi,

		struct iov_iter *iter)

static int dax_iomap_iter(struct iomap_iter *iomi, struct iov_iter *iter)

{

	const struct iomap *iomap = &iomi->iomap;

	const struct iomap *srcmap = iomap_iter_srcmap(iomi);

		if (pos >= end)

			return 0;

		if (iomap->type == IOMAP_HOLE || iomap->type == IOMAP_UNWRITTEN)

			return iov_iter_zero(min(length, end - pos), iter);

		if (iomap->type == IOMAP_HOLE || iomap->type == IOMAP_UNWRITTEN) {

			done = iov_iter_zero(min(length, end - pos), iter);

			return iomap_iter_advance(iomi, &done);

		}

	}

	/*

	}

	id = dax_read_lock();

	while (pos < end) {

	while ((pos = iomi->pos) < end) {

		unsigned offset = pos & (PAGE_SIZE - 1);

		const size_t size = ALIGN(length + offset, PAGE_SIZE);

		pgoff_t pgoff = dax_iomap_pgoff(iomap, pos);

			xfer = dax_copy_to_iter(dax_dev, pgoff, kaddr,

					map_len, iter);

		pos += xfer;

		length -= xfer;

		done += xfer;

		if (xfer == 0)

		length = xfer;

		ret = iomap_iter_advance(iomi, &length);

		if (!ret && xfer == 0)

			ret = -EFAULT;

		if (xfer < map_len)

			break;

	}

	dax_read_unlock(id);

	return done ? done : ret;

	return ret;

}

/**

		iomi.flags |= IOMAP_NOWAIT;

	while ((ret = iomap_iter(&iomi, ops)) > 0)

		iomi.processed = dax_iomap_iter(&iomi, iter);

		iomi.status = dax_iomap_iter(&iomi, iter);

	done = iomi.pos - iocb->ki_pos;

	iocb->ki_pos = iomi.pos;

	while ((error = iomap_iter(&iter, ops)) > 0) {

		if (WARN_ON_ONCE(iomap_length(&iter) < PAGE_SIZE)) {

			iter.processed = -EIO;	/* fs corruption? */

			iter.status = -EIO;	/* fs corruption? */

			continue;

		}

			ret |= VM_FAULT_MAJOR;

		}

		if (!(ret & VM_FAULT_ERROR))

			iter.processed = PAGE_SIZE;

		if (!(ret & VM_FAULT_ERROR)) {

			u64 length = PAGE_SIZE;

			iter.status = iomap_iter_advance(&iter, &length);

		}

	}

	if (iomap_errp)

			continue; /* actually breaks out of the loop */

		ret = dax_fault_iter(vmf, &iter, pfnp, &xas, &entry, true);

		if (ret != VM_FAULT_FALLBACK)

			iter.processed = PMD_SIZE;

		if (ret != VM_FAULT_FALLBACK) {

			u64 length = PMD_SIZE;

			iter.status = iomap_iter_advance(&iter, &length);

		}

	}

unlock_entry:

}

EXPORT_SYMBOL_GPL(dax_finish_sync_fault);

static loff_t dax_range_compare_iter(struct iomap_iter *it_src,

static int dax_range_compare_iter(struct iomap_iter *it_src,

		struct iomap_iter *it_dest, u64 len, bool *same)

{

	const struct iomap *smap = &it_src->iomap;

	const struct iomap *dmap = &it_dest->iomap;

	loff_t pos1 = it_src->pos, pos2 = it_dest->pos;

	u64 dest_len;

	void *saddr, *daddr;

	int id, ret;

	if (smap->type == IOMAP_HOLE && dmap->type == IOMAP_HOLE) {

		*same = true;

		return len;

		goto advance;

	}

	if (smap->type == IOMAP_HOLE || dmap->type == IOMAP_HOLE) {

	if (!*same)

		len = 0;

	dax_read_unlock(id);

	return len;

advance:

	dest_len = len;

	ret = iomap_iter_advance(it_src, &len);

	if (!ret)

		ret = iomap_iter_advance(it_dest, &dest_len);

	return ret;

out_unlock:

	dax_read_unlock(id);

		.len		= len,

		.flags		= IOMAP_DAX,

	};

	int ret, compared = 0;

	int ret, status;

	while ((ret = iomap_iter(&src_iter, ops)) > 0 &&

	       (ret = iomap_iter(&dst_iter, ops)) > 0) {

		compared = dax_range_compare_iter(&src_iter, &dst_iter,

		status = dax_range_compare_iter(&src_iter, &dst_iter,

				min(src_iter.len, dst_iter.len), same);

		if (compared < 0)

		if (status < 0)

			return ret;

		src_iter.processed = dst_iter.processed = compared;

		src_iter.status = dst_iter.status = status;

	}

	return ret;

}

		return false;

	/* atomic writes are all-or-nothing */

	if (flags & IOMAP_ATOMIC)

	if (flags & IOMAP_ATOMIC_HW)

		return false;

	/* can only try again if we wrote nothing */

				 unsigned int length)

{

	BUG_ON(current->journal_info);

	return iomap_zero_range(inode, from, length, NULL, &gfs2_iomap_ops);

	return iomap_zero_range(inode, from, length, NULL, &gfs2_iomap_ops,

			NULL);

}

#define GFS2_JTRUNC_REVOKES 8192