Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted

Pull I3C updates from Alexandre Belloni:
 "A new driver this cycle, for the AMD AXI I3C controller.

  There are also new features such as IBI wakeup support, SETAASA device
  discovery and ACPI support for the the DAA methods, meaning we can now
  communicate with the SPD devices on DDR5 modules.

  New driver:
   - AMD AXI I3C master controller

  Subsystem:
   - I3C Common Command Code (CCC) handling improvements, especially
     around GET CCCs
   - SETAASA device discovery support
   - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
     well as I2C devices on I3C bus
   - IBI-based wakeup support

  Drivers:
   - dw: SETAASA support
   - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
     controller support, PIO queue management support for HCI v1.2
   - renesas: improve suspend to RAM support, add runtime PM support"

* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
  i3c: dw: reduce do_daa time if there's no client
  i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
  i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
  i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
  i3c: dw: rename "pclk" to "apb" to match dt-binding
  i3c: dw: make struct dw_i3c_cmd smaller
  i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
  i3c: renesas: Don't register devices when ENTDAA times out
  i3c: master: dw-i3c-master: fix OD timing for first broadcast
  i3c: mipi-i3c-hci: Advertise IBI wakeup capability
  i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
  i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
  i3c: master: Reject IBI requests from non-IBI-capable devices
  i3c: master: Add helper to query bus wakeup requirements
  i3c: master: Report wakeup events for IBIs
  i3c: master: Support IBI-based wakeup capability
  i3c: master: Fix potential UAF in i3c_device_match()
  i3c: master: Fix potential UAF in i3c_device_uevent()
  i3c: Make dev->desc locking assumptions explicit
  i3c: master: Fix use-after-free of master->this
  ...

1 files changed, 658 insertions, 0 deletions

diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
new file mode 100644
index 000000000..3329b7ad5
--- /dev/null
+++ b/fs/ext4/move_extent.c
@@ -0,0 +1,658 @@
+// SPDX-License-Identifier: LGPL-2.1
+/*
+ * Copyright (c) 2008,2009 NEC Software Tohoku, Ltd.
+ * Written by Takashi Sato <t-sato@yk.jp.nec.com>
+ *            Akira Fujita <a-fujita@rs.jp.nec.com>
+ */
+
+#include <linux/fs.h>
+#include <linux/quotaops.h>
+#include <linux/slab.h>
+#include <linux/sched/mm.h>
+#include "ext4_jbd2.h"
+#include "ext4.h"
+#include "ext4_extents.h"
+
+#include <trace/events/ext4.h>
+
+struct mext_data {
+	struct inode *orig_inode;	/* Origin file inode */
+	struct inode *donor_inode;	/* Donor file inode */
+	struct ext4_map_blocks orig_map;/* Origin file's move mapping */
+	ext4_lblk_t donor_lblk;		/* Start block of the donor file */
+};
+
+/**
+ * ext4_double_down_write_data_sem() - write lock two inodes's i_data_sem
+ * @first: inode to be locked
+ * @second: inode to be locked
+ *
+ * Acquire write lock of i_data_sem of the two inodes
+ */
+void
+ext4_double_down_write_data_sem(struct inode *first, struct inode *second)
+{
+	if (first < second) {
+		down_write(&EXT4_I(first)->i_data_sem);
+		down_write_nested(&EXT4_I(second)->i_data_sem, I_DATA_SEM_OTHER);
+	} else {
+		down_write(&EXT4_I(second)->i_data_sem);
+		down_write_nested(&EXT4_I(first)->i_data_sem, I_DATA_SEM_OTHER);
+	}
+}
+
+/**
+ * ext4_double_up_write_data_sem - Release two inodes' write lock of i_data_sem
+ *
+ * @orig_inode:		original inode structure to be released its lock first
+ * @donor_inode:	donor inode structure to be released its lock second
+ * Release write lock of i_data_sem of two inodes (orig and donor).
+ */
+void
+ext4_double_up_write_data_sem(struct inode *orig_inode,
+			      struct inode *donor_inode)
+{
+	up_write(&EXT4_I(orig_inode)->i_data_sem);
+	up_write(&EXT4_I(donor_inode)->i_data_sem);
+}
+
+/* Grab and lock folio on both @inode1 and @inode2 by inode order. */
+static int mext_folio_double_lock(struct inode *inode1, struct inode *inode2,
+				  pgoff_t index1, pgoff_t index2, size_t len,
+				  struct folio *folio[2])
+{
+	struct address_space *mapping[2];
+	unsigned int flags;
+	fgf_t fgp_flags = FGP_WRITEBEGIN;
+
+	BUG_ON(!inode1 || !inode2);
+	if (inode1 < inode2) {
+		mapping[0] = inode1->i_mapping;
+		mapping[1] = inode2->i_mapping;
+	} else {
+		swap(index1, index2);
+		mapping[0] = inode2->i_mapping;
+		mapping[1] = inode1->i_mapping;
+	}
+
+	flags = memalloc_nofs_save();
+	fgp_flags |= fgf_set_order(len);
+	folio[0] = __filemap_get_folio(mapping[0], index1, fgp_flags,
+			mapping_gfp_mask(mapping[0]));
+	if (IS_ERR(folio[0])) {
+		memalloc_nofs_restore(flags);
+		return PTR_ERR(folio[0]);
+	}
+
+	folio[1] = __filemap_get_folio(mapping[1], index2, fgp_flags,
+			mapping_gfp_mask(mapping[1]));
+	memalloc_nofs_restore(flags);
+	if (IS_ERR(folio[1])) {
+		folio_unlock(folio[0]);
+		folio_put(folio[0]);
+		return PTR_ERR(folio[1]);
+	}
+	/*
+	 * __filemap_get_folio() may not wait on folio's writeback if
+	 * BDI not demand that. But it is reasonable to be very conservative
+	 * here and explicitly wait on folio's writeback
+	 */
+	folio_wait_writeback(folio[0]);
+	folio_wait_writeback(folio[1]);
+	if (inode1 > inode2)
+		swap(folio[0], folio[1]);
+
+	return 0;
+}
+
+static void mext_folio_double_unlock(struct folio *folio[2])
+{
+	folio_unlock(folio[0]);
+	folio_put(folio[0]);
+	folio_unlock(folio[1]);
+	folio_put(folio[1]);
+}
+
+/* Force folio buffers uptodate w/o dropping folio's lock */
+static int mext_folio_mkuptodate(struct folio *folio, size_t from, size_t to)
+{
+	struct inode *inode = folio->mapping->host;
+	sector_t block;
+	struct buffer_head *bh, *head;
+	unsigned int blocksize, block_start, block_end;
+	int nr = 0;
+	bool partial = false;
+
+	BUG_ON(!folio_test_locked(folio));
+	BUG_ON(folio_test_writeback(folio));
+
+	if (folio_test_uptodate(folio))
+		return 0;
+
+	blocksize = i_blocksize(inode);
+	head = folio_buffers(folio);
+	if (!head)
+		head = create_empty_buffers(folio, blocksize, 0);
+
+	block = folio_pos(folio) >> inode->i_blkbits;
+	block_end = 0;
+	bh = head;
+	do {
+		block_start = block_end;
+		block_end = block_start + blocksize;
+		if (block_end <= from || block_start >= to) {
+			if (!buffer_uptodate(bh))
+				partial = true;
+			continue;
+		}
+		if (buffer_uptodate(bh))
+			continue;
+		if (!buffer_mapped(bh)) {
+			int err = ext4_get_block(inode, block, bh, 0);
+			if (err)
+				return err;
+			if (!buffer_mapped(bh)) {
+				folio_zero_range(folio, block_start, blocksize);
+				set_buffer_uptodate(bh);
+				continue;
+			}
+		}
+		lock_buffer(bh);
+		if (buffer_uptodate(bh)) {
+			unlock_buffer(bh);
+			continue;
+		}
+		ext4_read_bh_nowait(bh, 0, NULL, false);
+		nr++;
+	} while (block++, (bh = bh->b_this_page) != head);
+
+	/* No io required */
+	if (!nr)
+		goto out;
+
+	bh = head;
+	do {
+		if (bh_offset(bh) + blocksize <= from)
+			continue;
+		if (bh_offset(bh) >= to)
+			break;
+		wait_on_buffer(bh);
+		if (buffer_uptodate(bh))
+			continue;
+		return -EIO;
+	} while ((bh = bh->b_this_page) != head);
+out:
+	if (!partial)
+		folio_mark_uptodate(folio);
+	return 0;
+}
+
+enum mext_move_type {MEXT_SKIP_EXTENT, MEXT_MOVE_EXTENT, MEXT_COPY_DATA};
+
+/*
+ * Start to move extent between the origin inode and the donor inode,
+ * hold one folio for each inode and check the candidate moving extent
+ * mapping status again.
+ */
+static int mext_move_begin(struct mext_data *mext, struct folio *folio[2],
+			   enum mext_move_type *move_type)
+{
+	struct inode *orig_inode = mext->orig_inode;
+	struct inode *donor_inode = mext->donor_inode;
+	unsigned int blkbits = orig_inode->i_blkbits;
+	struct ext4_map_blocks donor_map = {0};
+	loff_t orig_pos, donor_pos;
+	size_t move_len;
+	int ret;
+
+	orig_pos = ((loff_t)mext->orig_map.m_lblk) << blkbits;
+	donor_pos = ((loff_t)mext->donor_lblk) << blkbits;
+	ret = mext_folio_double_lock(orig_inode, donor_inode,
+			orig_pos >> PAGE_SHIFT, donor_pos >> PAGE_SHIFT,
+			((size_t)mext->orig_map.m_len) << blkbits, folio);
+	if (ret)
+		return ret;
+
+	/*
+	 * Check the origin inode's mapping information again under the
+	 * folio lock, as we do not hold the i_data_sem at all times, and
+	 * it may change during the concurrent write-back operation.
+	 */
+	if (mext->orig_map.m_seq != READ_ONCE(EXT4_I(orig_inode)->i_es_seq)) {
+		ret = -ESTALE;
+		goto error;
+	}
+
+	/* Adjust the moving length according to the length of shorter folio. */
+	move_len = umin(folio_next_pos(folio[0]) - orig_pos,
+			folio_next_pos(folio[1]) - donor_pos);
+	move_len >>= blkbits;
+	if (move_len < mext->orig_map.m_len)
+		mext->orig_map.m_len = move_len;
+
+	donor_map.m_lblk = mext->donor_lblk;
+	donor_map.m_len = mext->orig_map.m_len;
+	donor_map.m_flags = 0;
+	ret = ext4_map_blocks(NULL, donor_inode, &donor_map, 0);
+	if (ret < 0)
+		goto error;
+
+	/* Adjust the moving length according to the donor mapping length. */
+	mext->orig_map.m_len = donor_map.m_len;
+
+	/* Skip moving if the donor range is a hole or a delalloc extent. */
+	if (!(donor_map.m_flags & (EXT4_MAP_MAPPED | EXT4_MAP_UNWRITTEN)))
+		*move_type = MEXT_SKIP_EXTENT;
+	/* If both mapping ranges are unwritten, no need to copy data. */
+	else if ((mext->orig_map.m_flags & EXT4_MAP_UNWRITTEN) &&
+		 (donor_map.m_flags & EXT4_MAP_UNWRITTEN))
+		*move_type = MEXT_MOVE_EXTENT;
+	else
+		*move_type = MEXT_COPY_DATA;
+
+	return 0;
+error:
+	mext_folio_double_unlock(folio);
+	return ret;
+}
+
+/*
+ * Re-create the new moved mapping buffers of the original inode and commit
+ * the entire written range.
+ */
+static int mext_folio_mkwrite(struct inode *inode, struct folio *folio,
+			      size_t from, size_t to)
+{
+	unsigned int blocksize = i_blocksize(inode);
+	struct buffer_head *bh, *head;
+	size_t block_start, block_end;
+	sector_t block;
+	int ret;
+
+	head = folio_buffers(folio);
+	if (!head)
+		head = create_empty_buffers(folio, blocksize, 0);
+
+	block = folio_pos(folio) >> inode->i_blkbits;
+	block_end = 0;
+	bh = head;
+	do {
+		block_start = block_end;
+		block_end = block_start + blocksize;
+		if (block_end <= from || block_start >= to)
+			continue;
+
+		ret = ext4_get_block(inode, block, bh, 0);
+		if (ret)
+			return ret;
+	} while (block++, (bh = bh->b_this_page) != head);
+
+	block_commit_write(folio, from, to);
+	return 0;
+}
+
+/*
+ * Save the data in original inode extent blocks and replace one folio size
+ * aligned original inode extent with one or one partial donor inode extent,
+ * and then write out the saved data in new original inode blocks. Pass out
+ * the replaced block count through m_len. Return 0 on success, and an error
+ * code otherwise.
+ */
+static int mext_move_extent(struct mext_data *mext, u64 *m_len)
+{
+	struct inode *orig_inode = mext->orig_inode;
+	struct inode *donor_inode = mext->donor_inode;
+	struct ext4_map_blocks *orig_map = &mext->orig_map;
+	unsigned int blkbits = orig_inode->i_blkbits;
+	struct folio *folio[2] = {NULL, NULL};
+	loff_t from, length;
+	enum mext_move_type move_type = 0;
+	handle_t *handle;
+	u64 r_len = 0;
+	unsigned int credits;
+	int ret, ret2;
+
+	*m_len = 0;
+	trace_ext4_move_extent_enter(orig_inode, orig_map, donor_inode,
+				     mext->donor_lblk);
+	credits = ext4_chunk_trans_extent(orig_inode, 0) * 2;
+	handle = ext4_journal_start(orig_inode, EXT4_HT_MOVE_EXTENTS, credits);
+	if (IS_ERR(handle)) {
+		ret = PTR_ERR(handle);
+		goto out;
+	}
+	ext4_fc_mark_ineligible(orig_inode->i_sb, EXT4_FC_REASON_MOVE_EXT,
+				handle);
+
+	ret = mext_move_begin(mext, folio, &move_type);
+	if (ret)
+		goto stop_handle;
+
+	if (move_type == MEXT_SKIP_EXTENT)
+		goto unlock;
+
+	/*
+	 * Copy the data. First, read the original inode data into the page
+	 * cache. Then, release the existing mapping relationships and swap
+	 * the extent. Finally, re-establish the new mapping relationships
+	 * and dirty the page cache.
+	 */
+	if (move_type == MEXT_COPY_DATA) {
+		from = offset_in_folio(folio[0],
+				((loff_t)orig_map->m_lblk) << blkbits);
+		length = ((loff_t)orig_map->m_len) << blkbits;
+
+		ret = mext_folio_mkuptodate(folio[0], from, from + length);
+		if (ret)
+			goto unlock;
+	}
+
+	if (!filemap_release_folio(folio[0], 0) ||
+	    !filemap_release_folio(folio[1], 0)) {
+		ret = -EBUSY;
+		goto unlock;
+	}
+
+	/* Move extent */
+	ext4_double_down_write_data_sem(orig_inode, donor_inode);
+	*m_len = ext4_swap_extents(handle, orig_inode, donor_inode,
+				   orig_map->m_lblk, mext->donor_lblk,
+				   orig_map->m_len, 1, &ret);
+	ext4_double_up_write_data_sem(orig_inode, donor_inode);
+
+	/* A short-length swap cannot occur after a successful swap extent. */
+	if (WARN_ON_ONCE(!ret && (*m_len != orig_map->m_len)))
+		ret = -EIO;
+
+	if (!(*m_len) || (move_type == MEXT_MOVE_EXTENT))
+		goto unlock;
+
+	/* Copy data */
+	length = (*m_len) << blkbits;
+	ret2 = mext_folio_mkwrite(orig_inode, folio[0], from, from + length);
+	if (ret2) {
+		if (!ret)
+			ret = ret2;
+		goto repair_branches;
+	}
+	/*
+	 * Even in case of data=writeback it is reasonable to pin
+	 * inode to transaction, to prevent unexpected data loss.
+	 */
+	ret2 = ext4_jbd2_inode_add_write(handle, orig_inode,
+			((loff_t)orig_map->m_lblk) << blkbits, length);
+	if (!ret)
+		ret = ret2;
+unlock:
+	mext_folio_double_unlock(folio);
+stop_handle:
+	ext4_journal_stop(handle);
+out:
+	trace_ext4_move_extent_exit(orig_inode, orig_map->m_lblk, donor_inode,
+				    mext->donor_lblk, orig_map->m_len, *m_len,
+				    move_type, ret);
+	return ret;
+
+repair_branches:
+	ret2 = 0;
+	ext4_double_down_write_data_sem(orig_inode, donor_inode);
+	r_len = ext4_swap_extents(handle, donor_inode, orig_inode,
+				  mext->donor_lblk, orig_map->m_lblk,
+				  *m_len, 0, &ret2);
+	ext4_double_up_write_data_sem(orig_inode, donor_inode);
+	if (ret2 || r_len != *m_len) {
+		ext4_error_inode_block(orig_inode, (sector_t)(orig_map->m_lblk),
+				       EIO, "Unable to copy data block, data will be lost!");
+		ret = -EIO;
+	}
+	*m_len = 0;
+	goto unlock;
+}
+
+/*
+ * Check the validity of the basic filesystem environment and the
+ * inodes' support status.
+ */
+static int mext_check_validity(struct inode *orig_inode,
+			       struct inode *donor_inode)
+{
+	struct super_block *sb = orig_inode->i_sb;
+
+	/* origin and donor should be different inodes */
+	if (orig_inode == donor_inode) {
+		ext4_debug("ext4 move extent: The argument files should not be same inode [ino:orig %llu, donor %llu]\n",
+			   orig_inode->i_ino, donor_inode->i_ino);
+		return -EINVAL;
+	}
+
+	/* origin and donor should belone to the same filesystem */
+	if (orig_inode->i_sb != donor_inode->i_sb) {
+		ext4_debug("ext4 move extent: The argument files should be in same FS [ino:orig %llu, donor %llu]\n",
+			   orig_inode->i_ino, donor_inode->i_ino);
+		return -EINVAL;
+	}
+
+	/* Regular file check */
+	if (!S_ISREG(orig_inode->i_mode) || !S_ISREG(donor_inode->i_mode)) {
+		ext4_debug("ext4 move extent: The argument files should be regular file [ino:orig %llu, donor %llu]\n",
+			   orig_inode->i_ino, donor_inode->i_ino);
+		return -EINVAL;
+	}
+
+	if (ext4_has_feature_bigalloc(sb)) {
+		ext4_msg(sb, KERN_ERR,
+			 "Online defrag not supported with bigalloc");
+		return -EOPNOTSUPP;
+	}
+
+	if (IS_DAX(orig_inode)) {
+		ext4_msg(sb, KERN_ERR,
+			 "Online defrag not supported with DAX");
+		return -EOPNOTSUPP;
+	}
+
+	/*
+	 * TODO: it's not obvious how to swap blocks for inodes with full
+	 * journaling enabled.
+	 */
+	if (ext4_should_journal_data(orig_inode) ||
+	    ext4_should_journal_data(donor_inode)) {
+		ext4_msg(sb, KERN_ERR,
+			 "Online defrag not supported with data journaling");
+		return -EOPNOTSUPP;
+	}
+
+	if (IS_ENCRYPTED(orig_inode) || IS_ENCRYPTED(donor_inode)) {
+		ext4_msg(sb, KERN_ERR,
+			 "Online defrag not supported for encrypted files");
+		return -EOPNOTSUPP;
+	}
+
+	/* Ext4 move extent supports only extent based file */
+	if (!(ext4_test_inode_flag(orig_inode, EXT4_INODE_EXTENTS)) ||
+	    !(ext4_test_inode_flag(donor_inode, EXT4_INODE_EXTENTS))) {
+		ext4_msg(sb, KERN_ERR,
+			 "Online defrag not supported for non-extent files");
+		return -EOPNOTSUPP;
+	}
+
+	if (donor_inode->i_mode & (S_ISUID|S_ISGID)) {
+		ext4_debug("ext4 move extent: suid or sgid is set to donor file [ino:orig %llu, donor %llu]\n",
+			   orig_inode->i_ino, donor_inode->i_ino);
+		return -EINVAL;
+	}
+
+	if (IS_IMMUTABLE(donor_inode) || IS_APPEND(donor_inode)) {
+		ext4_debug("ext4 move extent: donor should not be immutable or append file [ino:orig %llu, donor %llu]\n",
+			   orig_inode->i_ino, donor_inode->i_ino);
+		return -EPERM;
+	}
+
+	/* Ext4 move extent does not support swap files */
+	if (IS_SWAPFILE(orig_inode) || IS_SWAPFILE(donor_inode)) {
+		ext4_debug("ext4 move extent: The argument files should not be swap files [ino:orig %llu, donor %llu]\n",
+			   orig_inode->i_ino, donor_inode->i_ino);
+		return -ETXTBSY;
+	}
+
+	if (ext4_is_quota_file(orig_inode) || ext4_is_quota_file(donor_inode)) {
+		ext4_debug("ext4 move extent: The argument files should not be quota files [ino:orig %llu, donor %llu]\n",
+			   orig_inode->i_ino, donor_inode->i_ino);
+		return -EOPNOTSUPP;
+	}
+
+	if ((!orig_inode->i_size) || (!donor_inode->i_size)) {
+		ext4_debug("ext4 move extent: File size is 0 byte\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * Check the moving range of ext4_move_extents() whether the files can be
+ * exchanged with each other, and adjust the length to fit within the file
+ * size. Return 0 on success, or a negative error value on failure.
+ */
+static int mext_check_adjust_range(struct inode *orig_inode,
+				   struct inode *donor_inode, __u64 orig_start,
+				   __u64 donor_start, __u64 *len)
+{
+	__u64 orig_eof, donor_eof;
+
+	/* Start offset should be same */
+	if ((orig_start & ~(PAGE_MASK >> orig_inode->i_blkbits)) !=
+	    (donor_start & ~(PAGE_MASK >> orig_inode->i_blkbits))) {
+		ext4_debug("ext4 move extent: orig and donor's start offsets are not aligned [ino:orig %llu, donor %llu]\n",
+			   orig_inode->i_ino, donor_inode->i_ino);
+		return -EINVAL;
+	}
+
+	if ((orig_start >= EXT_MAX_BLOCKS) ||
+	    (donor_start >= EXT_MAX_BLOCKS) ||
+	    (*len > EXT_MAX_BLOCKS) ||
+	    (donor_start + *len >= EXT_MAX_BLOCKS) ||
+	    (orig_start + *len >= EXT_MAX_BLOCKS))  {
+		ext4_debug("ext4 move extent: Can't handle over [%u] blocks [ino:orig %llu, donor %llu]\n",
+			   EXT_MAX_BLOCKS,
+			   orig_inode->i_ino, donor_inode->i_ino);
+		return -EINVAL;
+	}
+
+	orig_eof = EXT4_B_TO_LBLK(orig_inode, i_size_read(orig_inode));
+	donor_eof = EXT4_B_TO_LBLK(donor_inode, i_size_read(donor_inode));
+	if (orig_eof <= orig_start)
+		*len = 0;
+	else if (orig_eof < orig_start + *len - 1)
+		*len = orig_eof - orig_start;
+	if (donor_eof <= donor_start)
+		*len = 0;
+	else if (donor_eof < donor_start + *len - 1)
+		*len = donor_eof - donor_start;
+	if (!*len) {
+		ext4_debug("ext4 move extent: len should not be 0 [ino:orig %llu, donor %llu]\n",
+			   orig_inode->i_ino, donor_inode->i_ino);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * ext4_move_extents - Exchange the specified range of a file
+ *
+ * @o_filp:		file structure of the original file
+ * @d_filp:		file structure of the donor file
+ * @orig_blk:		start offset in block for orig
+ * @donor_blk:		start offset in block for donor
+ * @len:		the number of blocks to be moved
+ * @moved_len:		moved block length
+ *
+ * This function returns 0 and moved block length is set in moved_len
+ * if succeed, otherwise returns error value.
+ */
+int ext4_move_extents(struct file *o_filp, struct file *d_filp, __u64 orig_blk,
+		      __u64 donor_blk, __u64 len, __u64 *moved_len)
+{
+	struct inode *orig_inode = file_inode(o_filp);
+	struct inode *donor_inode = file_inode(d_filp);
+	struct mext_data mext;
+	struct super_block *sb = orig_inode->i_sb;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	int retries = 0;
+	u64 m_len;
+	int ret;
+
+	*moved_len = 0;
+
+	/* Protect orig and donor inodes against a truncate */
+	lock_two_nondirectories(orig_inode, donor_inode);
+
+	ret = mext_check_validity(orig_inode, donor_inode);
+	if (ret)
+		goto out;
+
+	/* Wait for all existing dio workers */
+	inode_dio_wait(orig_inode);
+	inode_dio_wait(donor_inode);
+
+	/* Check and adjust the specified move_extent range. */
+	ret = mext_check_adjust_range(orig_inode, donor_inode, orig_blk,
+				      donor_blk, &len);
+	if (ret)
+		goto out;
+
+	mext.orig_inode = orig_inode;
+	mext.donor_inode = donor_inode;
+	while (len) {
+		mext.orig_map.m_lblk = orig_blk;
+		mext.orig_map.m_len = len;
+		mext.orig_map.m_flags = 0;
+		mext.donor_lblk = donor_blk;
+
+		ret = ext4_map_blocks(NULL, orig_inode, &mext.orig_map, 0);
+		if (ret < 0)
+			goto out;
+
+		/* Skip moving if it is a hole or a delalloc extent. */
+		if (mext.orig_map.m_flags &
+		    (EXT4_MAP_MAPPED | EXT4_MAP_UNWRITTEN)) {
+			ret = mext_move_extent(&mext, &m_len);
+			*moved_len += m_len;
+			if (!ret)
+				goto next;
+
+			/* Move failed or partially failed. */
+			if (m_len) {
+				orig_blk += m_len;
+				donor_blk += m_len;
+				len -= m_len;
+			}
+			if (ret == -ESTALE)
+				continue;
+			if (ret == -ENOSPC &&
+			    ext4_should_retry_alloc(sb, &retries))
+				continue;
+			if (ret == -EBUSY &&
+			    sbi->s_journal && retries++ < 4 &&
+			    jbd2_journal_force_commit_nested(sbi->s_journal))
+				continue;
+
+			goto out;
+		}
+next:
+		orig_blk += mext.orig_map.m_len;
+		donor_blk += mext.orig_map.m_len;
+		len -= mext.orig_map.m_len;
+		retries = 0;
+	}
+
+out:
+	if (*moved_len) {
+		ext4_discard_preallocations(orig_inode);
+		ext4_discard_preallocations(donor_inode);
+	}
+
+	unlock_two_nondirectories(orig_inode, donor_inode);
+	return ret;
+}