Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 1671 insertions, 0 deletions

diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
new file mode 100644
index 0000000000..314b415ee5
--- /dev/null
+++ b/fs/ext2/inode.c
@@ -0,0 +1,1671 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/ext2/inode.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  from
+ *
+ *  linux/fs/minix/inode.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  Goal-directed block allocation by Stephen Tweedie
+ * 	(sct@dcs.ed.ac.uk), 1993, 1998
+ *  Big-endian to little-endian byte-swapping/bitmaps by
+ *        David S. Miller (davem@caip.rutgers.edu), 1995
+ *  64-bit file support on 64-bit platforms by Jakub Jelinek
+ * 	(jj@sunsite.ms.mff.cuni.cz)
+ *
+ *  Assorted race fixes, rewrite of ext2_get_block() by Al Viro, 2000
+ */
+
+#include <linux/time.h>
+#include <linux/highuid.h>
+#include <linux/pagemap.h>
+#include <linux/dax.h>
+#include <linux/blkdev.h>
+#include <linux/quotaops.h>
+#include <linux/writeback.h>
+#include <linux/buffer_head.h>
+#include <linux/mpage.h>
+#include <linux/fiemap.h>
+#include <linux/iomap.h>
+#include <linux/namei.h>
+#include <linux/uio.h>
+#include "ext2.h"
+#include "acl.h"
+#include "xattr.h"
+
+static int __ext2_write_inode(struct inode *inode, int do_sync);
+
+/*
+ * Test whether an inode is a fast symlink.
+ */
+static inline int ext2_inode_is_fast_symlink(struct inode *inode)
+{
+	int ea_blocks = EXT2_I(inode)->i_file_acl ?
+		(inode->i_sb->s_blocksize >> 9) : 0;
+
+	return (S_ISLNK(inode->i_mode) &&
+		inode->i_blocks - ea_blocks == 0);
+}
+
+static void ext2_truncate_blocks(struct inode *inode, loff_t offset);
+
+void ext2_write_failed(struct address_space *mapping, loff_t to)
+{
+	struct inode *inode = mapping->host;
+
+	if (to > inode->i_size) {
+		truncate_pagecache(inode, inode->i_size);
+		ext2_truncate_blocks(inode, inode->i_size);
+	}
+}
+
+/*
+ * Called at the last iput() if i_nlink is zero.
+ */
+void ext2_evict_inode(struct inode * inode)
+{
+	struct ext2_block_alloc_info *rsv;
+	int want_delete = 0;
+
+	if (!inode->i_nlink && !is_bad_inode(inode)) {
+		want_delete = 1;
+		dquot_initialize(inode);
+	} else {
+		dquot_drop(inode);
+	}
+
+	truncate_inode_pages_final(&inode->i_data);
+
+	if (want_delete) {
+		sb_start_intwrite(inode->i_sb);
+		/* set dtime */
+		EXT2_I(inode)->i_dtime	= ktime_get_real_seconds();
+		mark_inode_dirty(inode);
+		__ext2_write_inode(inode, inode_needs_sync(inode));
+		/* truncate to 0 */
+		inode->i_size = 0;
+		if (inode->i_blocks)
+			ext2_truncate_blocks(inode, 0);
+		ext2_xattr_delete_inode(inode);
+	}
+
+	invalidate_inode_buffers(inode);
+	clear_inode(inode);
+
+	ext2_discard_reservation(inode);
+	rsv = EXT2_I(inode)->i_block_alloc_info;
+	EXT2_I(inode)->i_block_alloc_info = NULL;
+	if (unlikely(rsv))
+		kfree(rsv);
+
+	if (want_delete) {
+		ext2_free_inode(inode);
+		sb_end_intwrite(inode->i_sb);
+	}
+}
+
+typedef struct {
+	__le32	*p;
+	__le32	key;
+	struct buffer_head *bh;
+} Indirect;
+
+static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
+{
+	p->key = *(p->p = v);
+	p->bh = bh;
+}
+
+static inline int verify_chain(Indirect *from, Indirect *to)
+{
+	while (from <= to && from->key == *from->p)
+		from++;
+	return (from > to);
+}
+
+/**
+ *	ext2_block_to_path - parse the block number into array of offsets
+ *	@inode: inode in question (we are only interested in its superblock)
+ *	@i_block: block number to be parsed
+ *	@offsets: array to store the offsets in
+ *      @boundary: set this non-zero if the referred-to block is likely to be
+ *             followed (on disk) by an indirect block.
+ *	To store the locations of file's data ext2 uses a data structure common
+ *	for UNIX filesystems - tree of pointers anchored in the inode, with
+ *	data blocks at leaves and indirect blocks in intermediate nodes.
+ *	This function translates the block number into path in that tree -
+ *	return value is the path length and @offsets[n] is the offset of
+ *	pointer to (n+1)th node in the nth one. If @block is out of range
+ *	(negative or too large) warning is printed and zero returned.
+ *
+ *	Note: function doesn't find node addresses, so no IO is needed. All
+ *	we need to know is the capacity of indirect blocks (taken from the
+ *	inode->i_sb).
+ */
+
+/*
+ * Portability note: the last comparison (check that we fit into triple
+ * indirect block) is spelled differently, because otherwise on an
+ * architecture with 32-bit longs and 8Kb pages we might get into trouble
+ * if our filesystem had 8Kb blocks. We might use long long, but that would
+ * kill us on x86. Oh, well, at least the sign propagation does not matter -
+ * i_block would have to be negative in the very beginning, so we would not
+ * get there at all.
+ */
+
+static int ext2_block_to_path(struct inode *inode,
+			long i_block, int offsets[4], int *boundary)
+{
+	int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb);
+	int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb);
+	const long direct_blocks = EXT2_NDIR_BLOCKS,
+		indirect_blocks = ptrs,
+		double_blocks = (1 << (ptrs_bits * 2));
+	int n = 0;
+	int final = 0;
+
+	if (i_block < 0) {
+		ext2_msg(inode->i_sb, KERN_WARNING,
+			"warning: %s: block < 0", __func__);
+	} else if (i_block < direct_blocks) {
+		offsets[n++] = i_block;
+		final = direct_blocks;
+	} else if ( (i_block -= direct_blocks) < indirect_blocks) {
+		offsets[n++] = EXT2_IND_BLOCK;
+		offsets[n++] = i_block;
+		final = ptrs;
+	} else if ((i_block -= indirect_blocks) < double_blocks) {
+		offsets[n++] = EXT2_DIND_BLOCK;
+		offsets[n++] = i_block >> ptrs_bits;
+		offsets[n++] = i_block & (ptrs - 1);
+		final = ptrs;
+	} else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
+		offsets[n++] = EXT2_TIND_BLOCK;
+		offsets[n++] = i_block >> (ptrs_bits * 2);
+		offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
+		offsets[n++] = i_block & (ptrs - 1);
+		final = ptrs;
+	} else {
+		ext2_msg(inode->i_sb, KERN_WARNING,
+			"warning: %s: block is too big", __func__);
+	}
+	if (boundary)
+		*boundary = final - 1 - (i_block & (ptrs - 1));
+
+	return n;
+}
+
+/**
+ *	ext2_get_branch - read the chain of indirect blocks leading to data
+ *	@inode: inode in question
+ *	@depth: depth of the chain (1 - direct pointer, etc.)
+ *	@offsets: offsets of pointers in inode/indirect blocks
+ *	@chain: place to store the result
+ *	@err: here we store the error value
+ *
+ *	Function fills the array of triples <key, p, bh> and returns %NULL
+ *	if everything went OK or the pointer to the last filled triple
+ *	(incomplete one) otherwise. Upon the return chain[i].key contains
+ *	the number of (i+1)-th block in the chain (as it is stored in memory,
+ *	i.e. little-endian 32-bit), chain[i].p contains the address of that
+ *	number (it points into struct inode for i==0 and into the bh->b_data
+ *	for i>0) and chain[i].bh points to the buffer_head of i-th indirect
+ *	block for i>0 and NULL for i==0. In other words, it holds the block
+ *	numbers of the chain, addresses they were taken from (and where we can
+ *	verify that chain did not change) and buffer_heads hosting these
+ *	numbers.
+ *
+ *	Function stops when it stumbles upon zero pointer (absent block)
+ *		(pointer to last triple returned, *@err == 0)
+ *	or when it gets an IO error reading an indirect block
+ *		(ditto, *@err == -EIO)
+ *	or when it notices that chain had been changed while it was reading
+ *		(ditto, *@err == -EAGAIN)
+ *	or when it reads all @depth-1 indirect blocks successfully and finds
+ *	the whole chain, all way to the data (returns %NULL, *err == 0).
+ */
+static Indirect *ext2_get_branch(struct inode *inode,
+				 int depth,
+				 int *offsets,
+				 Indirect chain[4],
+				 int *err)
+{
+	struct super_block *sb = inode->i_sb;
+	Indirect *p = chain;
+	struct buffer_head *bh;
+
+	*err = 0;
+	/* i_data is not going away, no lock needed */
+	add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets);
+	if (!p->key)
+		goto no_block;
+	while (--depth) {
+		bh = sb_bread(sb, le32_to_cpu(p->key));
+		if (!bh)
+			goto failure;
+		read_lock(&EXT2_I(inode)->i_meta_lock);
+		if (!verify_chain(chain, p))
+			goto changed;
+		add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
+		read_unlock(&EXT2_I(inode)->i_meta_lock);
+		if (!p->key)
+			goto no_block;
+	}
+	return NULL;
+
+changed:
+	read_unlock(&EXT2_I(inode)->i_meta_lock);
+	brelse(bh);
+	*err = -EAGAIN;
+	goto no_block;
+failure:
+	*err = -EIO;
+no_block:
+	return p;
+}
+
+/**
+ *	ext2_find_near - find a place for allocation with sufficient locality
+ *	@inode: owner
+ *	@ind: descriptor of indirect block.
+ *
+ *	This function returns the preferred place for block allocation.
+ *	It is used when heuristic for sequential allocation fails.
+ *	Rules are:
+ *	  + if there is a block to the left of our position - allocate near it.
+ *	  + if pointer will live in indirect block - allocate near that block.
+ *	  + if pointer will live in inode - allocate in the same cylinder group.
+ *
+ * In the latter case we colour the starting block by the callers PID to
+ * prevent it from clashing with concurrent allocations for a different inode
+ * in the same block group.   The PID is used here so that functionally related
+ * files will be close-by on-disk.
+ *
+ *	Caller must make sure that @ind is valid and will stay that way.
+ */
+
+static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind)
+{
+	struct ext2_inode_info *ei = EXT2_I(inode);
+	__le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
+	__le32 *p;
+	ext2_fsblk_t bg_start;
+	ext2_fsblk_t colour;
+
+	/* Try to find previous block */
+	for (p = ind->p - 1; p >= start; p--)
+		if (*p)
+			return le32_to_cpu(*p);
+
+	/* No such thing, so let's try location of indirect block */
+	if (ind->bh)
+		return ind->bh->b_blocknr;
+
+	/*
+	 * It is going to be referred from inode itself? OK, just put it into
+	 * the same cylinder group then.
+	 */
+	bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group);
+	colour = (current->pid % 16) *
+			(EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16);
+	return bg_start + colour;
+}
+
+/**
+ *	ext2_find_goal - find a preferred place for allocation.
+ *	@inode: owner
+ *	@block:  block we want
+ *	@partial: pointer to the last triple within a chain
+ *
+ *	Returns preferred place for a block (the goal).
+ */
+
+static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block,
+					  Indirect *partial)
+{
+	struct ext2_block_alloc_info *block_i;
+
+	block_i = EXT2_I(inode)->i_block_alloc_info;
+
+	/*
+	 * try the heuristic for sequential allocation,
+	 * failing that at least try to get decent locality.
+	 */
+	if (block_i && (block == block_i->last_alloc_logical_block + 1)
+		&& (block_i->last_alloc_physical_block != 0)) {
+		return block_i->last_alloc_physical_block + 1;
+	}
+
+	return ext2_find_near(inode, partial);
+}
+
+/**
+ *	ext2_blks_to_allocate: Look up the block map and count the number
+ *	of direct blocks need to be allocated for the given branch.
+ *
+ * 	@branch: chain of indirect blocks
+ *	@k: number of blocks need for indirect blocks
+ *	@blks: number of data blocks to be mapped.
+ *	@blocks_to_boundary:  the offset in the indirect block
+ *
+ *	return the number of direct blocks to allocate.
+ */
+static int
+ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks,
+		int blocks_to_boundary)
+{
+	unsigned long count = 0;
+
+	/*
+	 * Simple case, [t,d]Indirect block(s) has not allocated yet
+	 * then it's clear blocks on that path have not allocated
+	 */
+	if (k > 0) {
+		/* right now don't hanel cross boundary allocation */
+		if (blks < blocks_to_boundary + 1)
+			count += blks;
+		else
+			count += blocks_to_boundary + 1;
+		return count;
+	}
+
+	count++;
+	while (count < blks && count <= blocks_to_boundary
+		&& le32_to_cpu(*(branch[0].p + count)) == 0) {
+		count++;
+	}
+	return count;
+}
+
+/**
+ * ext2_alloc_blocks: Allocate multiple blocks needed for a branch.
+ * @inode: Owner.
+ * @goal: Preferred place for allocation.
+ * @indirect_blks: The number of blocks needed to allocate for indirect blocks.
+ * @blks: The number of blocks need to allocate for direct blocks.
+ * @new_blocks: On return it will store the new block numbers for
+ *	the indirect blocks(if needed) and the first direct block.
+ * @err: Error pointer.
+ *
+ * Return: Number of blocks allocated.
+ */
+static int ext2_alloc_blocks(struct inode *inode,
+			ext2_fsblk_t goal, int indirect_blks, int blks,
+			ext2_fsblk_t new_blocks[4], int *err)
+{
+	int target, i;
+	unsigned long count = 0;
+	int index = 0;
+	ext2_fsblk_t current_block = 0;
+	int ret = 0;
+
+	/*
+	 * Here we try to allocate the requested multiple blocks at once,
+	 * on a best-effort basis.
+	 * To build a branch, we should allocate blocks for
+	 * the indirect blocks(if not allocated yet), and at least
+	 * the first direct block of this branch.  That's the
+	 * minimum number of blocks need to allocate(required)
+	 */
+	target = blks + indirect_blks;
+
+	while (1) {
+		count = target;
+		/* allocating blocks for indirect blocks and direct blocks */
+		current_block = ext2_new_blocks(inode, goal, &count, err, 0);
+		if (*err)
+			goto failed_out;
+
+		target -= count;
+		/* allocate blocks for indirect blocks */
+		while (index < indirect_blks && count) {
+			new_blocks[index++] = current_block++;
+			count--;
+		}
+
+		if (count > 0)
+			break;
+	}
+
+	/* save the new block number for the first direct block */
+	new_blocks[index] = current_block;
+
+	/* total number of blocks allocated for direct blocks */
+	ret = count;
+	*err = 0;
+	return ret;
+failed_out:
+	for (i = 0; i <index; i++)
+		ext2_free_blocks(inode, new_blocks[i], 1);
+	if (index)
+		mark_inode_dirty(inode);
+	return ret;
+}
+
+/**
+ *	ext2_alloc_branch - allocate and set up a chain of blocks.
+ *	@inode: owner
+ *	@indirect_blks: depth of the chain (number of blocks to allocate)
+ *	@blks: number of allocated direct blocks
+ *	@goal: preferred place for allocation
+ *	@offsets: offsets (in the blocks) to store the pointers to next.
+ *	@branch: place to store the chain in.
+ *
+ *	This function allocates @num blocks, zeroes out all but the last one,
+ *	links them into chain and (if we are synchronous) writes them to disk.
+ *	In other words, it prepares a branch that can be spliced onto the
+ *	inode. It stores the information about that chain in the branch[], in
+ *	the same format as ext2_get_branch() would do. We are calling it after
+ *	we had read the existing part of chain and partial points to the last
+ *	triple of that (one with zero ->key). Upon the exit we have the same
+ *	picture as after the successful ext2_get_block(), except that in one
+ *	place chain is disconnected - *branch->p is still zero (we did not
+ *	set the last link), but branch->key contains the number that should
+ *	be placed into *branch->p to fill that gap.
+ *
+ *	If allocation fails we free all blocks we've allocated (and forget
+ *	their buffer_heads) and return the error value the from failed
+ *	ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain
+ *	as described above and return 0.
+ */
+
+static int ext2_alloc_branch(struct inode *inode,
+			int indirect_blks, int *blks, ext2_fsblk_t goal,
+			int *offsets, Indirect *branch)
+{
+	int blocksize = inode->i_sb->s_blocksize;
+	int i, n = 0;
+	int err = 0;
+	struct buffer_head *bh;
+	int num;
+	ext2_fsblk_t new_blocks[4];
+	ext2_fsblk_t current_block;
+
+	num = ext2_alloc_blocks(inode, goal, indirect_blks,
+				*blks, new_blocks, &err);
+	if (err)
+		return err;
+
+	branch[0].key = cpu_to_le32(new_blocks[0]);
+	/*
+	 * metadata blocks and data blocks are allocated.
+	 */
+	for (n = 1; n <= indirect_blks;  n++) {
+		/*
+		 * Get buffer_head for parent block, zero it out
+		 * and set the pointer to new one, then send
+		 * parent to disk.
+		 */
+		bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
+		if (unlikely(!bh)) {
+			err = -ENOMEM;
+			goto failed;
+		}
+		branch[n].bh = bh;
+		lock_buffer(bh);
+		memset(bh->b_data, 0, blocksize);
+		branch[n].p = (__le32 *) bh->b_data + offsets[n];
+		branch[n].key = cpu_to_le32(new_blocks[n]);
+		*branch[n].p = branch[n].key;
+		if ( n == indirect_blks) {
+			current_block = new_blocks[n];
+			/*
+			 * End of chain, update the last new metablock of
+			 * the chain to point to the new allocated
+			 * data blocks numbers
+			 */
+			for (i=1; i < num; i++)
+				*(branch[n].p + i) = cpu_to_le32(++current_block);
+		}
+		set_buffer_uptodate(bh);
+		unlock_buffer(bh);
+		mark_buffer_dirty_inode(bh, inode);
+		/* We used to sync bh here if IS_SYNC(inode).
+		 * But we now rely upon generic_write_sync()
+		 * and b_inode_buffers.  But not for directories.
+		 */
+		if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode))
+			sync_dirty_buffer(bh);
+	}
+	*blks = num;
+	return err;
+
+failed:
+	for (i = 1; i < n; i++)
+		bforget(branch[i].bh);
+	for (i = 0; i < indirect_blks; i++)
+		ext2_free_blocks(inode, new_blocks[i], 1);
+	ext2_free_blocks(inode, new_blocks[i], num);
+	return err;
+}
+
+/**
+ * ext2_splice_branch - splice the allocated branch onto inode.
+ * @inode: owner
+ * @block: (logical) number of block we are adding
+ * @where: location of missing link
+ * @num:   number of indirect blocks we are adding
+ * @blks:  number of direct blocks we are adding
+ *
+ * This function fills the missing link and does all housekeeping needed in
+ * inode (->i_blocks, etc.). In case of success we end up with the full
+ * chain to new block and return 0.
+ */
+static void ext2_splice_branch(struct inode *inode,
+			long block, Indirect *where, int num, int blks)
+{
+	int i;
+	struct ext2_block_alloc_info *block_i;
+	ext2_fsblk_t current_block;
+
+	block_i = EXT2_I(inode)->i_block_alloc_info;
+
+	/* XXX LOCKING probably should have i_meta_lock ?*/
+	/* That's it */
+
+	*where->p = where->key;
+
+	/*
+	 * Update the host buffer_head or inode to point to more just allocated
+	 * direct blocks blocks
+	 */
+	if (num == 0 && blks > 1) {
+		current_block = le32_to_cpu(where->key) + 1;
+		for (i = 1; i < blks; i++)
+			*(where->p + i ) = cpu_to_le32(current_block++);
+	}
+
+	/*
+	 * update the most recently allocated logical & physical block
+	 * in i_block_alloc_info, to assist find the proper goal block for next
+	 * allocation
+	 */
+	if (block_i) {
+		block_i->last_alloc_logical_block = block + blks - 1;
+		block_i->last_alloc_physical_block =
+				le32_to_cpu(where[num].key) + blks - 1;
+	}
+
+	/* We are done with atomic stuff, now do the rest of housekeeping */
+
+	/* had we spliced it onto indirect block? */
+	if (where->bh)
+		mark_buffer_dirty_inode(where->bh, inode);
+
+	inode_set_ctime_current(inode);
+	mark_inode_dirty(inode);
+}
+
+/*
+ * Allocation strategy is simple: if we have to allocate something, we will
+ * have to go the whole way to leaf. So let's do it before attaching anything
+ * to tree, set linkage between the newborn blocks, write them if sync is
+ * required, recheck the path, free and repeat if check fails, otherwise
+ * set the last missing link (that will protect us from any truncate-generated
+ * removals - all blocks on the path are immune now) and possibly force the
+ * write on the parent block.
+ * That has a nice additional property: no special recovery from the failed
+ * allocations is needed - we simply release blocks and do not touch anything
+ * reachable from inode.
+ *
+ * `handle' can be NULL if create == 0.
+ *
+ * return > 0, # of blocks mapped or allocated.
+ * return = 0, if plain lookup failed.
+ * return < 0, error case.
+ */
+static int ext2_get_blocks(struct inode *inode,
+			   sector_t iblock, unsigned long maxblocks,
+			   u32 *bno, bool *new, bool *boundary,
+			   int create)
+{
+	int err;
+	int offsets[4];
+	Indirect chain[4];
+	Indirect *partial;
+	ext2_fsblk_t goal;
+	int indirect_blks;
+	int blocks_to_boundary = 0;
+	int depth;
+	struct ext2_inode_info *ei = EXT2_I(inode);
+	int count = 0;
+	ext2_fsblk_t first_block = 0;
+
+	BUG_ON(maxblocks == 0);
+
+	depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
+
+	if (depth == 0)
+		return -EIO;
+
+	partial = ext2_get_branch(inode, depth, offsets, chain, &err);
+	/* Simplest case - block found, no allocation needed */
+	if (!partial) {
+		first_block = le32_to_cpu(chain[depth - 1].key);
+		count++;
+		/*map more blocks*/
+		while (count < maxblocks && count <= blocks_to_boundary) {
+			ext2_fsblk_t blk;
+
+			if (!verify_chain(chain, chain + depth - 1)) {
+				/*
+				 * Indirect block might be removed by
+				 * truncate while we were reading it.
+				 * Handling of that case: forget what we've
+				 * got now, go to reread.
+				 */
+				err = -EAGAIN;
+				count = 0;
+				partial = chain + depth - 1;
+				break;
+			}
+			blk = le32_to_cpu(*(chain[depth-1].p + count));
+			if (blk == first_block + count)
+				count++;
+			else
+				break;
+		}
+		if (err != -EAGAIN)
+			goto got_it;
+	}
+
+	/* Next simple case - plain lookup or failed read of indirect block */
+	if (!create || err == -EIO)
+		goto cleanup;
+
+	mutex_lock(&ei->truncate_mutex);
+	/*
+	 * If the indirect block is missing while we are reading
+	 * the chain(ext2_get_branch() returns -EAGAIN err), or
+	 * if the chain has been changed after we grab the semaphore,
+	 * (either because another process truncated this branch, or
+	 * another get_block allocated this branch) re-grab the chain to see if
+	 * the request block has been allocated or not.
+	 *
+	 * Since we already block the truncate/other get_block
+	 * at this point, we will have the current copy of the chain when we
+	 * splice the branch into the tree.
+	 */
+	if (err == -EAGAIN || !verify_chain(chain, partial)) {
+		while (partial > chain) {
+			brelse(partial->bh);
+			partial--;
+		}
+		partial = ext2_get_branch(inode, depth, offsets, chain, &err);
+		if (!partial) {
+			count++;
+			mutex_unlock(&ei->truncate_mutex);
+			goto got_it;
+		}
+
+		if (err) {
+			mutex_unlock(&ei->truncate_mutex);
+			goto cleanup;
+		}
+	}
+
+	/*
+	 * Okay, we need to do block allocation.  Lazily initialize the block
+	 * allocation info here if necessary
+	*/
+	if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
+		ext2_init_block_alloc_info(inode);
+
+	goal = ext2_find_goal(inode, iblock, partial);
+
+	/* the number of blocks need to allocate for [d,t]indirect blocks */
+	indirect_blks = (chain + depth) - partial - 1;
+	/*
+	 * Next look up the indirect map to count the total number of
+	 * direct blocks to allocate for this branch.
+	 */
+	count = ext2_blks_to_allocate(partial, indirect_blks,
+					maxblocks, blocks_to_boundary);
+	/*
+	 * XXX ???? Block out ext2_truncate while we alter the tree
+	 */
+	err = ext2_alloc_branch(inode, indirect_blks, &count, goal,
+				offsets + (partial - chain), partial);
+
+	if (err) {
+		mutex_unlock(&ei->truncate_mutex);
+		goto cleanup;
+	}
+
+	if (IS_DAX(inode)) {
+		/*
+		 * We must unmap blocks before zeroing so that writeback cannot
+		 * overwrite zeros with stale data from block device page cache.
+		 */
+		clean_bdev_aliases(inode->i_sb->s_bdev,
+				   le32_to_cpu(chain[depth-1].key),
+				   count);
+		/*
+		 * block must be initialised before we put it in the tree
+		 * so that it's not found by another thread before it's
+		 * initialised
+		 */
+		err = sb_issue_zeroout(inode->i_sb,
+				le32_to_cpu(chain[depth-1].key), count,
+				GFP_NOFS);
+		if (err) {
+			mutex_unlock(&ei->truncate_mutex);
+			goto cleanup;
+		}
+	}
+	*new = true;
+
+	ext2_splice_branch(inode, iblock, partial, indirect_blks, count);
+	mutex_unlock(&ei->truncate_mutex);
+got_it:
+	if (count > blocks_to_boundary)
+		*boundary = true;
+	err = count;
+	/* Clean up and exit */
+	partial = chain + depth - 1;	/* the whole chain */
+cleanup:
+	while (partial > chain) {
+		brelse(partial->bh);
+		partial--;
+	}
+	if (err > 0)
+		*bno = le32_to_cpu(chain[depth-1].key);
+	return err;
+}
+
+int ext2_get_block(struct inode *inode, sector_t iblock,
+		struct buffer_head *bh_result, int create)
+{
+	unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
+	bool new = false, boundary = false;
+	u32 bno;
+	int ret;
+
+	ret = ext2_get_blocks(inode, iblock, max_blocks, &bno, &new, &boundary,
+			create);
+	if (ret <= 0)
+		return ret;
+
+	map_bh(bh_result, inode->i_sb, bno);
+	bh_result->b_size = (ret << inode->i_blkbits);
+	if (new)
+		set_buffer_new(bh_result);
+	if (boundary)
+		set_buffer_boundary(bh_result);
+	return 0;
+
+}
+
+static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
+		unsigned flags, struct iomap *iomap, struct iomap *srcmap)
+{
+	unsigned int blkbits = inode->i_blkbits;
+	unsigned long first_block = offset >> blkbits;
+	unsigned long max_blocks = (length + (1 << blkbits) - 1) >> blkbits;
+	struct ext2_sb_info *sbi = EXT2_SB(inode->i_sb);
+	bool new = false, boundary = false;
+	u32 bno;
+	int ret;
+	bool create = flags & IOMAP_WRITE;
+
+	/*
+	 * For writes that could fill holes inside i_size on a
+	 * DIO_SKIP_HOLES filesystem we forbid block creations: only
+	 * overwrites are permitted.
+	 */
+	if ((flags & IOMAP_DIRECT) &&
+	    (first_block << blkbits) < i_size_read(inode))
+		create = 0;
+
+	/*
+	 * Writes that span EOF might trigger an IO size update on completion,
+	 * so consider them to be dirty for the purposes of O_DSYNC even if
+	 * there is no other metadata changes pending or have been made here.
+	 */
+	if ((flags & IOMAP_WRITE) && offset + length > i_size_read(inode))
+		iomap->flags |= IOMAP_F_DIRTY;
+
+	ret = ext2_get_blocks(inode, first_block, max_blocks,
+			&bno, &new, &boundary, create);
+	if (ret < 0)
+		return ret;
+
+	iomap->flags = 0;
+	iomap->offset = (u64)first_block << blkbits;
+	if (flags & IOMAP_DAX)
+		iomap->dax_dev = sbi->s_daxdev;
+	else
+		iomap->bdev = inode->i_sb->s_bdev;
+
+	if (ret == 0) {
+		/*
+		 * Switch to buffered-io for writing to holes in a non-extent
+		 * based filesystem to avoid stale data exposure problem.
+		 */
+		if (!create && (flags & IOMAP_WRITE) && (flags & IOMAP_DIRECT))
+			return -ENOTBLK;
+		iomap->type = IOMAP_HOLE;
+		iomap->addr = IOMAP_NULL_ADDR;
+		iomap->length = 1 << blkbits;
+	} else {
+		iomap->type = IOMAP_MAPPED;
+		iomap->addr = (u64)bno << blkbits;
+		if (flags & IOMAP_DAX)
+			iomap->addr += sbi->s_dax_part_off;
+		iomap->length = (u64)ret << blkbits;
+		iomap->flags |= IOMAP_F_MERGED;
+	}
+
+	if (new)
+		iomap->flags |= IOMAP_F_NEW;
+	return 0;
+}
+
+static int
+ext2_iomap_end(struct inode *inode, loff_t offset, loff_t length,
+		ssize_t written, unsigned flags, struct iomap *iomap)
+{
+	/*
+	 * Switch to buffered-io in case of any error.
+	 * Blocks allocated can be used by the buffered-io path.
+	 */
+	if ((flags & IOMAP_DIRECT) && (flags & IOMAP_WRITE) && written == 0)
+		return -ENOTBLK;
+
+	if (iomap->type == IOMAP_MAPPED &&
+	    written < length &&
+	    (flags & IOMAP_WRITE))
+		ext2_write_failed(inode->i_mapping, offset + length);
+	return 0;
+}
+
+const struct iomap_ops ext2_iomap_ops = {
+	.iomap_begin		= ext2_iomap_begin,
+	.iomap_end		= ext2_iomap_end,
+};
+
+int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+		u64 start, u64 len)
+{
+	int ret;
+
+	inode_lock(inode);
+	len = min_t(u64, len, i_size_read(inode));
+	ret = iomap_fiemap(inode, fieinfo, start, len, &ext2_iomap_ops);
+	inode_unlock(inode);
+
+	return ret;
+}
+
+static int ext2_read_folio(struct file *file, struct folio *folio)
+{
+	return mpage_read_folio(folio, ext2_get_block);
+}
+
+static void ext2_readahead(struct readahead_control *rac)
+{
+	mpage_readahead(rac, ext2_get_block);
+}
+
+static int
+ext2_write_begin(struct file *file, struct address_space *mapping,
+		loff_t pos, unsigned len, struct page **pagep, void **fsdata)
+{
+	int ret;
+
+	ret = block_write_begin(mapping, pos, len, pagep, ext2_get_block);
+	if (ret < 0)
+		ext2_write_failed(mapping, pos + len);
+	return ret;
+}
+
+static int ext2_write_end(struct file *file, struct address_space *mapping,
+			loff_t pos, unsigned len, unsigned copied,
+			struct page *page, void *fsdata)
+{
+	int ret;
+
+	ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
+	if (ret < len)
+		ext2_write_failed(mapping, pos + len);
+	return ret;
+}
+
+static sector_t ext2_bmap(struct address_space *mapping, sector_t block)
+{
+	return generic_block_bmap(mapping,block,ext2_get_block);
+}
+
+static int
+ext2_writepages(struct address_space *mapping, struct writeback_control *wbc)
+{
+	return mpage_writepages(mapping, wbc, ext2_get_block);
+}
+
+static int
+ext2_dax_writepages(struct address_space *mapping, struct writeback_control *wbc)
+{
+	struct ext2_sb_info *sbi = EXT2_SB(mapping->host->i_sb);
+
+	return dax_writeback_mapping_range(mapping, sbi->s_daxdev, wbc);
+}
+
+const struct address_space_operations ext2_aops = {
+	.dirty_folio		= block_dirty_folio,
+	.invalidate_folio	= block_invalidate_folio,
+	.read_folio		= ext2_read_folio,
+	.readahead		= ext2_readahead,
+	.write_begin		= ext2_write_begin,
+	.write_end		= ext2_write_end,
+	.bmap			= ext2_bmap,
+	.direct_IO		= noop_direct_IO,
+	.writepages		= ext2_writepages,
+	.migrate_folio		= buffer_migrate_folio,
+	.is_partially_uptodate	= block_is_partially_uptodate,
+	.error_remove_page	= generic_error_remove_page,
+};
+
+static const struct address_space_operations ext2_dax_aops = {
+	.writepages		= ext2_dax_writepages,
+	.direct_IO		= noop_direct_IO,
+	.dirty_folio		= noop_dirty_folio,
+};
+
+/*
+ * Probably it should be a library function... search for first non-zero word
+ * or memcmp with zero_page, whatever is better for particular architecture.
+ * Linus?
+ */
+static inline int all_zeroes(__le32 *p, __le32 *q)
+{
+	while (p < q)
+		if (*p++)
+			return 0;
+	return 1;
+}
+
+/**
+ *	ext2_find_shared - find the indirect blocks for partial truncation.
+ *	@inode:	  inode in question
+ *	@depth:	  depth of the affected branch
+ *	@offsets: offsets of pointers in that branch (see ext2_block_to_path)
+ *	@chain:	  place to store the pointers to partial indirect blocks
+ *	@top:	  place to the (detached) top of branch
+ *
+ *	This is a helper function used by ext2_truncate().
+ *
+ *	When we do truncate() we may have to clean the ends of several indirect
+ *	blocks but leave the blocks themselves alive. Block is partially
+ *	truncated if some data below the new i_size is referred from it (and
+ *	it is on the path to the first completely truncated data block, indeed).
+ *	We have to free the top of that path along with everything to the right
+ *	of the path. Since no allocation past the truncation point is possible
+ *	until ext2_truncate() finishes, we may safely do the latter, but top
+ *	of branch may require special attention - pageout below the truncation
+ *	point might try to populate it.
+ *
+ *	We atomically detach the top of branch from the tree, store the block
+ *	number of its root in *@top, pointers to buffer_heads of partially
+ *	truncated blocks - in @chain[].bh and pointers to their last elements
+ *	that should not be removed - in @chain[].p. Return value is the pointer
+ *	to last filled element of @chain.
+ *
+ *	The work left to caller to do the actual freeing of subtrees:
+ *		a) free the subtree starting from *@top
+ *		b) free the subtrees whose roots are stored in
+ *			(@chain[i].p+1 .. end of @chain[i].bh->b_data)
+ *		c) free the subtrees growing from the inode past the @chain[0].p
+ *			(no partially truncated stuff there).
+ */
+
+static Indirect *ext2_find_shared(struct inode *inode,
+				int depth,
+				int offsets[4],
+				Indirect chain[4],
+				__le32 *top)
+{
+	Indirect *partial, *p;
+	int k, err;
+
+	*top = 0;
+	for (k = depth; k > 1 && !offsets[k-1]; k--)
+		;
+	partial = ext2_get_branch(inode, k, offsets, chain, &err);
+	if (!partial)
+		partial = chain + k-1;
+	/*
+	 * If the branch acquired continuation since we've looked at it -
+	 * fine, it should all survive and (new) top doesn't belong to us.
+	 */
+	write_lock(&EXT2_I(inode)->i_meta_lock);
+	if (!partial->key && *partial->p) {
+		write_unlock(&EXT2_I(inode)->i_meta_lock);
+		goto no_top;
+	}
+	for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
+		;
+	/*
+	 * OK, we've found the last block that must survive. The rest of our
+	 * branch should be detached before unlocking. However, if that rest
+	 * of branch is all ours and does not grow immediately from the inode
+	 * it's easier to cheat and just decrement partial->p.
+	 */
+	if (p == chain + k - 1 && p > chain) {
+		p->p--;
+	} else {
+		*top = *p->p;
+		*p->p = 0;
+	}
+	write_unlock(&EXT2_I(inode)->i_meta_lock);
+
+	while(partial > p)
+	{
+		brelse(partial->bh);
+		partial--;
+	}
+no_top:
+	return partial;
+}
+
+/**
+ *	ext2_free_data - free a list of data blocks
+ *	@inode:	inode we are dealing with
+ *	@p:	array of block numbers
+ *	@q:	points immediately past the end of array
+ *
+ *	We are freeing all blocks referred from that array (numbers are
+ *	stored as little-endian 32-bit) and updating @inode->i_blocks
+ *	appropriately.
+ */
+static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q)
+{
+	ext2_fsblk_t block_to_free = 0, count = 0;
+	ext2_fsblk_t nr;
+
+	for ( ; p < q ; p++) {
+		nr = le32_to_cpu(*p);
+		if (nr) {
+			*p = 0;
+			/* accumulate blocks to free if they're contiguous */
+			if (count == 0)
+				goto free_this;
+			else if (block_to_free == nr - count)
+				count++;
+			else {
+				ext2_free_blocks (inode, block_to_free, count);
+				mark_inode_dirty(inode);
+			free_this:
+				block_to_free = nr;
+				count = 1;
+			}
+		}
+	}
+	if (count > 0) {
+		ext2_free_blocks (inode, block_to_free, count);
+		mark_inode_dirty(inode);
+	}
+}
+
+/**
+ *	ext2_free_branches - free an array of branches
+ *	@inode:	inode we are dealing with
+ *	@p:	array of block numbers
+ *	@q:	pointer immediately past the end of array
+ *	@depth:	depth of the branches to free
+ *
+ *	We are freeing all blocks referred from these branches (numbers are
+ *	stored as little-endian 32-bit) and updating @inode->i_blocks
+ *	appropriately.
+ */
+static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth)
+{
+	struct buffer_head * bh;
+	ext2_fsblk_t nr;
+
+	if (depth--) {
+		int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
+		for ( ; p < q ; p++) {
+			nr = le32_to_cpu(*p);
+			if (!nr)
+				continue;
+			*p = 0;
+			bh = sb_bread(inode->i_sb, nr);
+			/*
+			 * A read failure? Report error and clear slot
+			 * (should be rare).
+			 */ 
+			if (!bh) {
+				ext2_error(inode->i_sb, "ext2_free_branches",
+					"Read failure, inode=%ld, block=%ld",
+					inode->i_ino, nr);
+				continue;
+			}
+			ext2_free_branches(inode,
+					   (__le32*)bh->b_data,
+					   (__le32*)bh->b_data + addr_per_block,
+					   depth);
+			bforget(bh);
+			ext2_free_blocks(inode, nr, 1);
+			mark_inode_dirty(inode);
+		}
+	} else
+		ext2_free_data(inode, p, q);
+}
+
+/* mapping->invalidate_lock must be held when calling this function */
+static void __ext2_truncate_blocks(struct inode *inode, loff_t offset)
+{
+	__le32 *i_data = EXT2_I(inode)->i_data;
+	struct ext2_inode_info *ei = EXT2_I(inode);
+	int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
+	int offsets[4];
+	Indirect chain[4];
+	Indirect *partial;
+	__le32 nr = 0;
+	int n;
+	long iblock;
+	unsigned blocksize;
+	blocksize = inode->i_sb->s_blocksize;
+	iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb);
+
+#ifdef CONFIG_FS_DAX
+	WARN_ON(!rwsem_is_locked(&inode->i_mapping->invalidate_lock));
+#endif
+
+	n = ext2_block_to_path(inode, iblock, offsets, NULL);
+	if (n == 0)
+		return;
+
+	/*
+	 * From here we block out all ext2_get_block() callers who want to
+	 * modify the block allocation tree.
+	 */
+	mutex_lock(&ei->truncate_mutex);
+
+	if (n == 1) {
+		ext2_free_data(inode, i_data+offsets[0],
+					i_data + EXT2_NDIR_BLOCKS);
+		goto do_indirects;
+	}
+
+	partial = ext2_find_shared(inode, n, offsets, chain, &nr);
+	/* Kill the top of shared branch (already detached) */
+	if (nr) {
+		if (partial == chain)
+			mark_inode_dirty(inode);
+		else
+			mark_buffer_dirty_inode(partial->bh, inode);
+		ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial);
+	}
+	/* Clear the ends of indirect blocks on the shared branch */
+	while (partial > chain) {
+		ext2_free_branches(inode,
+				   partial->p + 1,
+				   (__le32*)partial->bh->b_data+addr_per_block,
+				   (chain+n-1) - partial);
+		mark_buffer_dirty_inode(partial->bh, inode);
+		brelse (partial->bh);
+		partial--;
+	}
+do_indirects:
+	/* Kill the remaining (whole) subtrees */
+	switch (offsets[0]) {
+		default:
+			nr = i_data[EXT2_IND_BLOCK];
+			if (nr) {
+				i_data[EXT2_IND_BLOCK] = 0;
+				mark_inode_dirty(inode);
+				ext2_free_branches(inode, &nr, &nr+1, 1);
+			}
+			fallthrough;
+		case EXT2_IND_BLOCK:
+			nr = i_data[EXT2_DIND_BLOCK];
+			if (nr) {
+				i_data[EXT2_DIND_BLOCK] = 0;
+				mark_inode_dirty(inode);
+				ext2_free_branches(inode, &nr, &nr+1, 2);
+			}
+			fallthrough;
+		case EXT2_DIND_BLOCK:
+			nr = i_data[EXT2_TIND_BLOCK];
+			if (nr) {
+				i_data[EXT2_TIND_BLOCK] = 0;
+				mark_inode_dirty(inode);
+				ext2_free_branches(inode, &nr, &nr+1, 3);
+			}
+			break;
+		case EXT2_TIND_BLOCK:
+			;
+	}
+
+	ext2_discard_reservation(inode);
+
+	mutex_unlock(&ei->truncate_mutex);
+}
+
+static void ext2_truncate_blocks(struct inode *inode, loff_t offset)
+{
+	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+	    S_ISLNK(inode->i_mode)))
+		return;
+	if (ext2_inode_is_fast_symlink(inode))
+		return;
+
+	filemap_invalidate_lock(inode->i_mapping);
+	__ext2_truncate_blocks(inode, offset);
+	filemap_invalidate_unlock(inode->i_mapping);
+}
+
+static int ext2_setsize(struct inode *inode, loff_t newsize)
+{
+	int error;
+
+	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+	    S_ISLNK(inode->i_mode)))
+		return -EINVAL;
+	if (ext2_inode_is_fast_symlink(inode))
+		return -EINVAL;
+	if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+		return -EPERM;
+
+	inode_dio_wait(inode);
+
+	if (IS_DAX(inode))
+		error = dax_truncate_page(inode, newsize, NULL,
+					  &ext2_iomap_ops);
+	else
+		error = block_truncate_page(inode->i_mapping,
+				newsize, ext2_get_block);
+	if (error)
+		return error;
+
+	filemap_invalidate_lock(inode->i_mapping);
+	truncate_setsize(inode, newsize);
+	__ext2_truncate_blocks(inode, newsize);
+	filemap_invalidate_unlock(inode->i_mapping);
+
+	inode->i_mtime = inode_set_ctime_current(inode);
+	if (inode_needs_sync(inode)) {
+		sync_mapping_buffers(inode->i_mapping);
+		sync_inode_metadata(inode, 1);
+	} else {
+		mark_inode_dirty(inode);
+	}
+
+	return 0;
+}
+
+static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino,
+					struct buffer_head **p)
+{
+	struct buffer_head * bh;
+	unsigned long block_group;
+	unsigned long block;
+	unsigned long offset;
+	struct ext2_group_desc * gdp;
+
+	*p = NULL;
+	if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) ||
+	    ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
+		goto Einval;
+
+	block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb);
+	gdp = ext2_get_group_desc(sb, block_group, NULL);
+	if (!gdp)
+		goto Egdp;
+	/*
+	 * Figure out the offset within the block group inode table
+	 */
+	offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb);
+	block = le32_to_cpu(gdp->bg_inode_table) +
+		(offset >> EXT2_BLOCK_SIZE_BITS(sb));
+	if (!(bh = sb_bread(sb, block)))
+		goto Eio;
+
+	*p = bh;
+	offset &= (EXT2_BLOCK_SIZE(sb) - 1);
+	return (struct ext2_inode *) (bh->b_data + offset);
+
+Einval:
+	ext2_error(sb, "ext2_get_inode", "bad inode number: %lu",
+		   (unsigned long) ino);
+	return ERR_PTR(-EINVAL);
+Eio:
+	ext2_error(sb, "ext2_get_inode",
+		   "unable to read inode block - inode=%lu, block=%lu",
+		   (unsigned long) ino, block);
+Egdp:
+	return ERR_PTR(-EIO);
+}
+
+void ext2_set_inode_flags(struct inode *inode)
+{
+	unsigned int flags = EXT2_I(inode)->i_flags;
+
+	inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME |
+				S_DIRSYNC | S_DAX);
+	if (flags & EXT2_SYNC_FL)
+		inode->i_flags |= S_SYNC;
+	if (flags & EXT2_APPEND_FL)
+		inode->i_flags |= S_APPEND;
+	if (flags & EXT2_IMMUTABLE_FL)
+		inode->i_flags |= S_IMMUTABLE;
+	if (flags & EXT2_NOATIME_FL)
+		inode->i_flags |= S_NOATIME;
+	if (flags & EXT2_DIRSYNC_FL)
+		inode->i_flags |= S_DIRSYNC;
+	if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode))
+		inode->i_flags |= S_DAX;
+}
+
+void ext2_set_file_ops(struct inode *inode)
+{
+	inode->i_op = &ext2_file_inode_operations;
+	inode->i_fop = &ext2_file_operations;
+	if (IS_DAX(inode))
+		inode->i_mapping->a_ops = &ext2_dax_aops;
+	else
+		inode->i_mapping->a_ops = &ext2_aops;
+}
+
+struct inode *ext2_iget (struct super_block *sb, unsigned long ino)
+{
+	struct ext2_inode_info *ei;
+	struct buffer_head * bh = NULL;
+	struct ext2_inode *raw_inode;
+	struct inode *inode;
+	long ret = -EIO;
+	int n;
+	uid_t i_uid;
+	gid_t i_gid;
+
+	inode = iget_locked(sb, ino);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+	if (!(inode->i_state & I_NEW))
+		return inode;
+
+	ei = EXT2_I(inode);
+	ei->i_block_alloc_info = NULL;
+
+	raw_inode = ext2_get_inode(inode->i_sb, ino, &bh);
+	if (IS_ERR(raw_inode)) {
+		ret = PTR_ERR(raw_inode);
+ 		goto bad_inode;
+	}
+
+	inode->i_mode = le16_to_cpu(raw_inode->i_mode);
+	i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
+	i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
+	if (!(test_opt (inode->i_sb, NO_UID32))) {
+		i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
+		i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
+	}
+	i_uid_write(inode, i_uid);
+	i_gid_write(inode, i_gid);
+	set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
+	inode->i_size = le32_to_cpu(raw_inode->i_size);
+	inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime);
+	inode_set_ctime(inode, (signed)le32_to_cpu(raw_inode->i_ctime), 0);
+	inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime);
+	inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = 0;
+	ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
+	/* We now have enough fields to check if the inode was active or not.
+	 * This is needed because nfsd might try to access dead inodes
+	 * the test is that same one that e2fsck uses
+	 * NeilBrown 1999oct15
+	 */
+	if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) {
+		/* this inode is deleted */
+		ret = -ESTALE;
+		goto bad_inode;
+	}
+	inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
+	ei->i_flags = le32_to_cpu(raw_inode->i_flags);
+	ext2_set_inode_flags(inode);
+	ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
+	ei->i_frag_no = raw_inode->i_frag;
+	ei->i_frag_size = raw_inode->i_fsize;
+	ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
+	ei->i_dir_acl = 0;
+
+	if (ei->i_file_acl &&
+	    !ext2_data_block_valid(EXT2_SB(sb), ei->i_file_acl, 1)) {
+		ext2_error(sb, "ext2_iget", "bad extended attribute block %u",
+			   ei->i_file_acl);
+		ret = -EFSCORRUPTED;
+		goto bad_inode;
+	}
+
+	if (S_ISREG(inode->i_mode))
+		inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
+	else
+		ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
+	if (i_size_read(inode) < 0) {
+		ret = -EFSCORRUPTED;
+		goto bad_inode;
+	}
+	ei->i_dtime = 0;
+	inode->i_generation = le32_to_cpu(raw_inode->i_generation);
+	ei->i_state = 0;
+	ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
+	ei->i_dir_start_lookup = 0;
+
+	/*
+	 * NOTE! The in-memory inode i_data array is in little-endian order
+	 * even on big-endian machines: we do NOT byteswap the block numbers!
+	 */
+	for (n = 0; n < EXT2_N_BLOCKS; n++)
+		ei->i_data[n] = raw_inode->i_block[n];
+
+	if (S_ISREG(inode->i_mode)) {
+		ext2_set_file_ops(inode);
+	} else if (S_ISDIR(inode->i_mode)) {
+		inode->i_op = &ext2_dir_inode_operations;
+		inode->i_fop = &ext2_dir_operations;
+		inode->i_mapping->a_ops = &ext2_aops;
+	} else if (S_ISLNK(inode->i_mode)) {
+		if (ext2_inode_is_fast_symlink(inode)) {
+			inode->i_link = (char *)ei->i_data;
+			inode->i_op = &ext2_fast_symlink_inode_operations;
+			nd_terminate_link(ei->i_data, inode->i_size,
+				sizeof(ei->i_data) - 1);
+		} else {
+			inode->i_op = &ext2_symlink_inode_operations;
+			inode_nohighmem(inode);
+			inode->i_mapping->a_ops = &ext2_aops;
+		}
+	} else {
+		inode->i_op = &ext2_special_inode_operations;
+		if (raw_inode->i_block[0])
+			init_special_inode(inode, inode->i_mode,
+			   old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
+		else 
+			init_special_inode(inode, inode->i_mode,
+			   new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
+	}
+	brelse (bh);
+	unlock_new_inode(inode);
+	return inode;
+	
+bad_inode:
+	brelse(bh);
+	iget_failed(inode);
+	return ERR_PTR(ret);
+}
+
+static int __ext2_write_inode(struct inode *inode, int do_sync)
+{
+	struct ext2_inode_info *ei = EXT2_I(inode);
+	struct super_block *sb = inode->i_sb;
+	ino_t ino = inode->i_ino;
+	uid_t uid = i_uid_read(inode);
+	gid_t gid = i_gid_read(inode);
+	struct buffer_head * bh;
+	struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh);
+	int n;
+	int err = 0;
+
+	if (IS_ERR(raw_inode))
+ 		return -EIO;
+
+	/* For fields not tracking in the in-memory inode,
+	 * initialise them to zero for new inodes. */
+	if (ei->i_state & EXT2_STATE_NEW)
+		memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size);
+
+	raw_inode->i_mode = cpu_to_le16(inode->i_mode);
+	if (!(test_opt(sb, NO_UID32))) {
+		raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid));
+		raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid));
+/*
+ * Fix up interoperability with old kernels. Otherwise, old inodes get
+ * re-used with the upper 16 bits of the uid/gid intact
+ */
+		if (!ei->i_dtime) {
+			raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid));
+			raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid));
+		} else {
+			raw_inode->i_uid_high = 0;
+			raw_inode->i_gid_high = 0;
+		}
+	} else {
+		raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid));
+		raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid));
+		raw_inode->i_uid_high = 0;
+		raw_inode->i_gid_high = 0;
+	}
+	raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
+	raw_inode->i_size = cpu_to_le32(inode->i_size);
+	raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
+	raw_inode->i_ctime = cpu_to_le32(inode_get_ctime(inode).tv_sec);
+	raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
+
+	raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
+	raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
+	raw_inode->i_flags = cpu_to_le32(ei->i_flags);
+	raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
+	raw_inode->i_frag = ei->i_frag_no;
+	raw_inode->i_fsize = ei->i_frag_size;
+	raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
+	if (!S_ISREG(inode->i_mode))
+		raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
+	else {
+		raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32);
+		if (inode->i_size > 0x7fffffffULL) {
+			if (!EXT2_HAS_RO_COMPAT_FEATURE(sb,
+					EXT2_FEATURE_RO_COMPAT_LARGE_FILE) ||
+			    EXT2_SB(sb)->s_es->s_rev_level ==
+					cpu_to_le32(EXT2_GOOD_OLD_REV)) {
+			       /* If this is the first large file
+				* created, add a flag to the superblock.
+				*/
+				spin_lock(&EXT2_SB(sb)->s_lock);
+				ext2_update_dynamic_rev(sb);
+				EXT2_SET_RO_COMPAT_FEATURE(sb,
+					EXT2_FEATURE_RO_COMPAT_LARGE_FILE);
+				spin_unlock(&EXT2_SB(sb)->s_lock);
+				ext2_sync_super(sb, EXT2_SB(sb)->s_es, 1);
+			}
+		}
+	}
+	
+	raw_inode->i_generation = cpu_to_le32(inode->i_generation);
+	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
+		if (old_valid_dev(inode->i_rdev)) {
+			raw_inode->i_block[0] =
+				cpu_to_le32(old_encode_dev(inode->i_rdev));
+			raw_inode->i_block[1] = 0;
+		} else {
+			raw_inode->i_block[0] = 0;
+			raw_inode->i_block[1] =
+				cpu_to_le32(new_encode_dev(inode->i_rdev));
+			raw_inode->i_block[2] = 0;
+		}
+	} else for (n = 0; n < EXT2_N_BLOCKS; n++)
+		raw_inode->i_block[n] = ei->i_data[n];
+	mark_buffer_dirty(bh);
+	if (do_sync) {
+		sync_dirty_buffer(bh);
+		if (buffer_req(bh) && !buffer_uptodate(bh)) {
+			printk ("IO error syncing ext2 inode [%s:%08lx]\n",
+				sb->s_id, (unsigned long) ino);
+			err = -EIO;
+		}
+	}
+	ei->i_state &= ~EXT2_STATE_NEW;
+	brelse (bh);
+	return err;
+}
+
+int ext2_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+	return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
+}
+
+int ext2_getattr(struct mnt_idmap *idmap, const struct path *path,
+		 struct kstat *stat, u32 request_mask, unsigned int query_flags)
+{
+	struct inode *inode = d_inode(path->dentry);
+	struct ext2_inode_info *ei = EXT2_I(inode);
+	unsigned int flags;
+
+	flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
+	if (flags & EXT2_APPEND_FL)
+		stat->attributes |= STATX_ATTR_APPEND;
+	if (flags & EXT2_COMPR_FL)
+		stat->attributes |= STATX_ATTR_COMPRESSED;
+	if (flags & EXT2_IMMUTABLE_FL)
+		stat->attributes |= STATX_ATTR_IMMUTABLE;
+	if (flags & EXT2_NODUMP_FL)
+		stat->attributes |= STATX_ATTR_NODUMP;
+	stat->attributes_mask |= (STATX_ATTR_APPEND |
+			STATX_ATTR_COMPRESSED |
+			STATX_ATTR_ENCRYPTED |
+			STATX_ATTR_IMMUTABLE |
+			STATX_ATTR_NODUMP);
+
+	generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
+	return 0;
+}
+
+int ext2_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
+		 struct iattr *iattr)
+{
+	struct inode *inode = d_inode(dentry);
+	int error;
+
+	error = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
+	if (error)
+		return error;
+
+	if (is_quota_modification(&nop_mnt_idmap, inode, iattr)) {
+		error = dquot_initialize(inode);
+		if (error)
+			return error;
+	}
+	if (i_uid_needs_update(&nop_mnt_idmap, iattr, inode) ||
+	    i_gid_needs_update(&nop_mnt_idmap, iattr, inode)) {
+		error = dquot_transfer(&nop_mnt_idmap, inode, iattr);
+		if (error)
+			return error;
+	}
+	if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) {
+		error = ext2_setsize(inode, iattr->ia_size);
+		if (error)
+			return error;
+	}
+	setattr_copy(&nop_mnt_idmap, inode, iattr);
+	if (iattr->ia_valid & ATTR_MODE)
+		error = posix_acl_chmod(&nop_mnt_idmap, dentry, inode->i_mode);
+	mark_inode_dirty(inode);
+
+	return error;
+}