static int lp_register(int nr, struct parport *port)
{
	lp_table[nr].dev = parport_register_device(port, "lp",
						   lp_preempt, NULL, NULL, 0,
						   (void *) &lp_table[nr]);
	if (lp_table[nr].dev == NULL)
		return 1;
	lp_table[nr].flags |= LP_EXIST;

	if (reset)
		lp_reset(nr);

	device_create(lp_class, port->dev, MKDEV(LP_MAJOR, nr), NULL,
		      "lp%d", nr);

	printk(KERN_INFO "lp%d: using %s (%s).\n", nr, port->name,
	       (port->irq == PARPORT_IRQ_NONE)?"polling":"interrupt-driven");

#ifdef CONFIG_LP_CONSOLE
	if (!nr) {
		if (port->modes & PARPORT_MODE_SAFEININT) {
			register_console(&lpcons);
			console_registered = port;
			printk (KERN_INFO "lp%d: console ready\n", CONSOLE_LP);
		} else
			printk (KERN_ERR "lp%d: cannot run console on %s\n",
				CONSOLE_LP, port->name);
	}
#endif

	return 0;
}


static int __init lp_setup (char *str)
{
	static int parport_ptr;
	int x;

	if (get_option(&str, &x)) {
		if (x == 0) {
			/* disable driver on "lp=" or "lp=0" */
			parport_nr[0] = LP_PARPORT_OFF;
		} else {
			printk(KERN_WARNING "warning: 'lp=0x%x' is deprecated, ignored\n", x);
			return 0;
		}
	} else if (!strncmp(str, "parport", 7)) {
		int n = simple_strtoul(str+7, NULL, 10);
		if (parport_ptr < LP_NO)
			parport_nr[parport_ptr++] = n;
		else
			printk(KERN_INFO "lp: too many ports, %s ignored.\n",
			       str);
	} else if (!strcmp(str, "auto")) {
		parport_nr[0] = LP_PARPORT_AUTO;
	} else if (!strcmp(str, "none")) {
		if (parport_ptr < LP_NO)
			parport_nr[parport_ptr++] = LP_PARPORT_NONE;
		else
			printk(KERN_INFO "lp: too many ports, %s ignored.\n",
			       str);
	} else if (!strcmp(str, "reset")) {
		reset = 1;
	}
	return 1;
}

char: lp: fix possible integer overflow in lp_setup()

The lp_setup() code doesn't apply any bounds checking when passing
"lp=none", and only in this case, resulting in an overflow of the
parport_nr[] array. All versions in Git history are affected.

Reported-By: Roee Hay <roee.hay@hcl.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


static void lp_console_write (struct console *co, const char *s,
			      unsigned count)
{
	struct pardevice *dev = lp_table[CONSOLE_LP].dev;
	struct parport *port = dev->port;
	ssize_t written;

	if (parport_claim (dev))
		/* Nothing we can do. */
		return;

	parport_set_timeout (dev, 0);

	/* Go to compatibility mode. */
	parport_negotiate (port, IEEE1284_MODE_COMPAT);

	do {
		/* Write the data, converting LF->CRLF as we go. */
		ssize_t canwrite = count;
		char *lf = memchr (s, '\n', count);
		if (lf)
			canwrite = lf - s;

		if (canwrite > 0) {
			written = parport_write (port, s, canwrite);

			if (written <= 0)
				continue;

			s += written;
			count -= written;
			canwrite -= written;
		}

		if (lf && canwrite <= 0) {
			const char *crlf = "\r\n";
			int i = 2;

			/* Dodge the original '\n', and put '\r\n' instead. */
			s++;
			count--;
			do {
				written = parport_write (port, crlf, i);
				if (written > 0)
					i -= written, crlf += written;
			} while (i > 0 && (CONSOLE_LP_STRICT || written > 0));
		}
	} while (count > 0 && (CONSOLE_LP_STRICT || written > 0));

	parport_release (dev);
}


static int lp_preempt(void *handle)
{
	struct lp_struct *this_lp = (struct lp_struct *)handle;
	set_bit(LP_PREEMPT_REQUEST, &this_lp->bits);
	return (1);
}


static void lp_attach (struct parport *port)
{
	unsigned int i;

	switch (parport_nr[0]) {
	case LP_PARPORT_UNSPEC:
	case LP_PARPORT_AUTO:
		if (parport_nr[0] == LP_PARPORT_AUTO &&
		    port->probe_info[0].class != PARPORT_CLASS_PRINTER)
			return;
		if (lp_count == LP_NO) {
			printk(KERN_INFO "lp: ignoring parallel port (max. %d)\n",LP_NO);
			return;
		}
		if (!lp_register(lp_count, port))
			lp_count++;
		break;

	default:
		for (i = 0; i < LP_NO; i++) {
			if (port->number == parport_nr[i]) {
				if (!lp_register(i, port))
					lp_count++;
				break;
			}
		}
		break;
	}
}


static int lp_negotiate(struct parport * port, int mode)
{
	if (parport_negotiate (port, mode) != 0) {
		mode = IEEE1284_MODE_COMPAT;
		parport_negotiate (port, mode);
	}

	return (mode);
}


static void lp_claim_parport_or_block(struct lp_struct *this_lp)
{
	if (!test_and_set_bit(LP_PARPORT_CLAIMED, &this_lp->bits)) {
		parport_claim_or_block (this_lp->dev);
	}
}


static ssize_t lp_write(struct file * file, const char __user * buf,
		        size_t count, loff_t *ppos)
{
	unsigned int minor = iminor(file_inode(file));
	struct parport *port = lp_table[minor].dev->port;
	char *kbuf = lp_table[minor].lp_buffer;
	ssize_t retv = 0;
	ssize_t written;
	size_t copy_size = count;
	int nonblock = ((file->f_flags & O_NONBLOCK) ||
			(LP_F(minor) & LP_ABORT));

#ifdef LP_STATS
	if (time_after(jiffies, lp_table[minor].lastcall + LP_TIME(minor)))
		lp_table[minor].runchars = 0;

	lp_table[minor].lastcall = jiffies;
#endif

	/* Need to copy the data from user-space. */
	if (copy_size > LP_BUFFER_SIZE)
		copy_size = LP_BUFFER_SIZE;

	if (mutex_lock_interruptible(&lp_table[minor].port_mutex))
		return -EINTR;

	if (copy_from_user (kbuf, buf, copy_size)) {
		retv = -EFAULT;
		goto out_unlock;
	}

 	/* Claim Parport or sleep until it becomes available
 	 */
	lp_claim_parport_or_block (&lp_table[minor]);
	/* Go to the proper mode. */
	lp_table[minor].current_mode = lp_negotiate (port,
						     lp_table[minor].best_mode);

	parport_set_timeout (lp_table[minor].dev,
			     (nonblock ? PARPORT_INACTIVITY_O_NONBLOCK
			      : lp_table[minor].timeout));

	if ((retv = lp_wait_ready (minor, nonblock)) == 0)
	do {
		/* Write the data. */
		written = parport_write (port, kbuf, copy_size);
		if (written > 0) {
			copy_size -= written;
			count -= written;
			buf  += written;
			retv += written;
		}

		if (signal_pending (current)) {
			if (retv == 0)
				retv = -EINTR;

			break;
		}

		if (copy_size > 0) {
			/* incomplete write -> check error ! */
			int error;

			parport_negotiate (lp_table[minor].dev->port,
					   IEEE1284_MODE_COMPAT);
			lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;

			error = lp_wait_ready (minor, nonblock);

			if (error) {
				if (retv == 0)
					retv = error;
				break;
			} else if (nonblock) {
				if (retv == 0)
					retv = -EAGAIN;
				break;
			}

			parport_yield_blocking (lp_table[minor].dev);
			lp_table[minor].current_mode
			  = lp_negotiate (port,
					  lp_table[minor].best_mode);

		} else if (need_resched())
			schedule ();

		if (count) {
			copy_size = count;
			if (copy_size > LP_BUFFER_SIZE)
				copy_size = LP_BUFFER_SIZE;

			if (copy_from_user(kbuf, buf, copy_size)) {
				if (retv == 0)
					retv = -EFAULT;
				break;
			}
		}
	} while (count > 0);

	if (test_and_clear_bit(LP_PREEMPT_REQUEST,
			       &lp_table[minor].bits)) {
		printk(KERN_INFO "lp%d releasing parport\n", minor);
		parport_negotiate (lp_table[minor].dev->port,
				   IEEE1284_MODE_COMPAT);
		lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
		lp_release_parport (&lp_table[minor]);
	}
out_unlock:
	mutex_unlock(&lp_table[minor].port_mutex);

 	return retv;
}


static int lp_release(struct inode * inode, struct file * file)
{
	unsigned int minor = iminor(inode);

	lp_claim_parport_or_block (&lp_table[minor]);
	parport_negotiate (lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
	lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
	lp_release_parport (&lp_table[minor]);
	kfree(lp_table[minor].lp_buffer);
	lp_table[minor].lp_buffer = NULL;
	LP_F(minor) &= ~LP_BUSY;
	return 0;
}


static int lp_wait_ready(int minor, int nonblock)
{
	int error = 0;

	/* If we're not in compatibility mode, we're ready now! */
	if (lp_table[minor].current_mode != IEEE1284_MODE_COMPAT) {
	  return (0);
	}

	do {
		error = lp_check_status (minor);
		if (error && (nonblock || (LP_F(minor) & LP_ABORT)))
			break;
		if (signal_pending (current)) {
			error = -EINTR;
			break;
		}
	} while (error);
	return error;
}


static int __init lp_init (void)
{
	int i, err = 0;

	if (parport_nr[0] == LP_PARPORT_OFF)
		return 0;

	for (i = 0; i < LP_NO; i++) {
		lp_table[i].dev = NULL;
		lp_table[i].flags = 0;
		lp_table[i].chars = LP_INIT_CHAR;
		lp_table[i].time = LP_INIT_TIME;
		lp_table[i].wait = LP_INIT_WAIT;
		lp_table[i].lp_buffer = NULL;
#ifdef LP_STATS
		lp_table[i].lastcall = 0;
		lp_table[i].runchars = 0;
		memset (&lp_table[i].stats, 0, sizeof (struct lp_stats));
#endif
		lp_table[i].last_error = 0;
		init_waitqueue_head (&lp_table[i].waitq);
		init_waitqueue_head (&lp_table[i].dataq);
		mutex_init(&lp_table[i].port_mutex);
		lp_table[i].timeout = 10 * HZ;
	}

	if (register_chrdev (LP_MAJOR, "lp", &lp_fops)) {
		printk (KERN_ERR "lp: unable to get major %d\n", LP_MAJOR);
		return -EIO;
	}

	lp_class = class_create(THIS_MODULE, "printer");
	if (IS_ERR(lp_class)) {
		err = PTR_ERR(lp_class);
		goto out_reg;
	}

	if (parport_register_driver (&lp_driver)) {
		printk (KERN_ERR "lp: unable to register with parport\n");
		err = -EIO;
		goto out_class;
	}

	if (!lp_count) {
		printk (KERN_INFO "lp: driver loaded but no devices found\n");
#ifndef CONFIG_PARPORT_1284
		if (parport_nr[0] == LP_PARPORT_AUTO)
			printk (KERN_INFO "lp: (is IEEE 1284 support enabled?)\n");
#endif
	}

	return 0;

out_class:
	class_destroy(lp_class);
out_reg:
	unregister_chrdev(LP_MAJOR, "lp");
	return err;
}


static void lp_cleanup_module (void)
{
	unsigned int offset;

	parport_unregister_driver (&lp_driver);

#ifdef CONFIG_LP_CONSOLE
	unregister_console (&lpcons);
#endif

	unregister_chrdev(LP_MAJOR, "lp");
	for (offset = 0; offset < LP_NO; offset++) {
		if (lp_table[offset].dev == NULL)
			continue;
		parport_unregister_device(lp_table[offset].dev);
		device_destroy(lp_class, MKDEV(LP_MAJOR, offset));
	}
	class_destroy(lp_class);
}


static int lp_do_ioctl(unsigned int minor, unsigned int cmd,
	unsigned long arg, void __user *argp)
{
	int status;
	int retval = 0;

#ifdef LP_DEBUG
	printk(KERN_DEBUG "lp%d ioctl, cmd: 0x%x, arg: 0x%lx\n", minor, cmd, arg);
#endif
	if (minor >= LP_NO)
		return -ENODEV;
	if ((LP_F(minor) & LP_EXIST) == 0)
		return -ENODEV;
	switch ( cmd ) {
		case LPTIME:
			if (arg > UINT_MAX / HZ)
				return -EINVAL;
			LP_TIME(minor) = arg * HZ/100;
			break;
		case LPCHAR:
			LP_CHAR(minor) = arg;
			break;
		case LPABORT:
			if (arg)
				LP_F(minor) |= LP_ABORT;
			else
				LP_F(minor) &= ~LP_ABORT;
			break;
		case LPABORTOPEN:
			if (arg)
				LP_F(minor) |= LP_ABORTOPEN;
			else
				LP_F(minor) &= ~LP_ABORTOPEN;
			break;
		case LPCAREFUL:
			if (arg)
				LP_F(minor) |= LP_CAREFUL;
			else
				LP_F(minor) &= ~LP_CAREFUL;
			break;
		case LPWAIT:
			LP_WAIT(minor) = arg;
			break;
		case LPSETIRQ:
			return -EINVAL;
			break;
		case LPGETIRQ:
			if (copy_to_user(argp, &LP_IRQ(minor),
					sizeof(int)))
				return -EFAULT;
			break;
		case LPGETSTATUS:
			if (mutex_lock_interruptible(&lp_table[minor].port_mutex))
				return -EINTR;
			lp_claim_parport_or_block (&lp_table[minor]);
			status = r_str(minor);
			lp_release_parport (&lp_table[minor]);
			mutex_unlock(&lp_table[minor].port_mutex);

			if (copy_to_user(argp, &status, sizeof(int)))
				return -EFAULT;
			break;
		case LPRESET:
			lp_reset(minor);
			break;
#ifdef LP_STATS
		case LPGETSTATS:
			if (copy_to_user(argp, &LP_STAT(minor),
					sizeof(struct lp_stats)))
				return -EFAULT;
			if (capable(CAP_SYS_ADMIN))
				memset(&LP_STAT(minor), 0,
						sizeof(struct lp_stats));
			break;
#endif
 		case LPGETFLAGS:
 			status = LP_F(minor);
			if (copy_to_user(argp, &status, sizeof(int)))
				return -EFAULT;
			break;

		default:
			retval = -EINVAL;
	}
	return retval;
}


static int lp_set_timeout(unsigned int minor, struct timeval *par_timeout)
{
	long to_jiffies;

	/* Convert to jiffies, place in lp_table */
	if ((par_timeout->tv_sec < 0) ||
	    (par_timeout->tv_usec < 0)) {
		return -EINVAL;
	}
	to_jiffies = DIV_ROUND_UP(par_timeout->tv_usec, 1000000/HZ);
	to_jiffies += par_timeout->tv_sec * (long) HZ;
	if (to_jiffies <= 0) {
		return -EINVAL;
	}
	lp_table[minor].timeout = to_jiffies;
	return 0;
}


static long lp_compat_ioctl(struct file *file, unsigned int cmd,
			unsigned long arg)
{
	unsigned int minor;
	struct timeval par_timeout;
	int ret;

	minor = iminor(file_inode(file));
	mutex_lock(&lp_mutex);
	switch (cmd) {
	case LPSETTIMEOUT:
		if (compat_get_timeval(&par_timeout, compat_ptr(arg))) {
			ret = -EFAULT;
			break;
		}
		ret = lp_set_timeout(minor, &par_timeout);
		break;
#ifdef LP_STATS
	case LPGETSTATS:
		/* FIXME: add an implementation if you set LP_STATS */
		ret = -EINVAL;
		break;
#endif
	default:
		ret = lp_do_ioctl(minor, cmd, arg, compat_ptr(arg));
		break;
	}
	mutex_unlock(&lp_mutex);

	return ret;
}


static void lp_detach (struct parport *port)
{
	/* Write this some day. */
#ifdef CONFIG_LP_CONSOLE
	if (console_registered == port) {
		unregister_console(&lpcons);
		console_registered = NULL;
	}
#endif /* CONFIG_LP_CONSOLE */
}


static void lp_error (int minor)
{
	DEFINE_WAIT(wait);
	int polling;

	if (LP_F(minor) & LP_ABORT)
		return;

	polling = lp_table[minor].dev->port->irq == PARPORT_IRQ_NONE;
	if (polling) lp_release_parport (&lp_table[minor]);
	prepare_to_wait(&lp_table[minor].waitq, &wait, TASK_INTERRUPTIBLE);
	schedule_timeout(LP_TIMEOUT_POLLED);
	finish_wait(&lp_table[minor].waitq, &wait);
	if (polling) lp_claim_parport_or_block (&lp_table[minor]);
	else parport_yield_blocking (lp_table[minor].dev);
}


static ssize_t lp_read(struct file * file, char __user * buf,
		       size_t count, loff_t *ppos)
{
	DEFINE_WAIT(wait);
	unsigned int minor=iminor(file_inode(file));
	struct parport *port = lp_table[minor].dev->port;
	ssize_t retval = 0;
	char *kbuf = lp_table[minor].lp_buffer;
	int nonblock = ((file->f_flags & O_NONBLOCK) ||
			(LP_F(minor) & LP_ABORT));

	if (count > LP_BUFFER_SIZE)
		count = LP_BUFFER_SIZE;

	if (mutex_lock_interruptible(&lp_table[minor].port_mutex))
		return -EINTR;

	lp_claim_parport_or_block (&lp_table[minor]);

	parport_set_timeout (lp_table[minor].dev,
			     (nonblock ? PARPORT_INACTIVITY_O_NONBLOCK
			      : lp_table[minor].timeout));

	parport_negotiate (lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
	if (parport_negotiate (lp_table[minor].dev->port,
			       IEEE1284_MODE_NIBBLE)) {
		retval = -EIO;
		goto out;
	}

	while (retval == 0) {
		retval = parport_read (port, kbuf, count);

		if (retval > 0)
			break;

		if (nonblock) {
			retval = -EAGAIN;
			break;
		}

		/* Wait for data. */

		if (lp_table[minor].dev->port->irq == PARPORT_IRQ_NONE) {
			parport_negotiate (lp_table[minor].dev->port,
					   IEEE1284_MODE_COMPAT);
			lp_error (minor);
			if (parport_negotiate (lp_table[minor].dev->port,
					       IEEE1284_MODE_NIBBLE)) {
				retval = -EIO;
				goto out;
			}
		} else {
			prepare_to_wait(&lp_table[minor].waitq, &wait, TASK_INTERRUPTIBLE);
			schedule_timeout(LP_TIMEOUT_POLLED);
			finish_wait(&lp_table[minor].waitq, &wait);
		}

		if (signal_pending (current)) {
			retval = -ERESTARTSYS;
			break;
		}

		cond_resched ();
	}
	parport_negotiate (lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
 out:
	lp_release_parport (&lp_table[minor]);

	if (retval > 0 && copy_to_user (buf, kbuf, retval))
		retval = -EFAULT;

	mutex_unlock(&lp_table[minor].port_mutex);

	return retval;
}


static struct buffer_head *__ext4_find_entry(struct inode *dir,
					     struct ext4_filename *fname,
					     struct ext4_dir_entry_2 **res_dir,
					     int *inlined)
{
	struct super_block *sb;
	struct buffer_head *bh_use[NAMEI_RA_SIZE];
	struct buffer_head *bh, *ret = NULL;
	ext4_lblk_t start, block;
	const u8 *name = fname->usr_fname->name;
	size_t ra_max = 0;	/* Number of bh's in the readahead
				   buffer, bh_use[] */
	size_t ra_ptr = 0;	/* Current index into readahead
				   buffer */
	ext4_lblk_t  nblocks;
	int i, namelen, retval;

	*res_dir = NULL;
	sb = dir->i_sb;
	namelen = fname->usr_fname->len;
	if (namelen > EXT4_NAME_LEN)
		return NULL;

	if (ext4_has_inline_data(dir)) {
		int has_inline_data = 1;
		ret = ext4_find_inline_entry(dir, fname, res_dir,
					     &has_inline_data);
		if (has_inline_data) {
			if (inlined)
				*inlined = 1;
			goto cleanup_and_exit;
		}
	}

	if ((namelen <= 2) && (name[0] == '.') &&
	    (name[1] == '.' || name[1] == '\0')) {
		/*
		 * "." or ".." will only be in the first block
		 * NFS may look up ".."; "." should be handled by the VFS
		 */
		block = start = 0;
		nblocks = 1;
		goto restart;
	}
	if (is_dx(dir)) {
		ret = ext4_dx_find_entry(dir, fname, res_dir);
		/*
		 * On success, or if the error was file not found,
		 * return.  Otherwise, fall back to doing a search the
		 * old fashioned way.
		 */
		if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR)
			goto cleanup_and_exit;
		dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
			       "falling back\n"));
		ret = NULL;
	}
	nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
	if (!nblocks) {
		ret = NULL;
		goto cleanup_and_exit;
	}
	start = EXT4_I(dir)->i_dir_start_lookup;
	if (start >= nblocks)
		start = 0;
	block = start;
restart:
	do {
		/*
		 * We deal with the read-ahead logic here.
		 */
		cond_resched();
		if (ra_ptr >= ra_max) {
			/* Refill the readahead buffer */
			ra_ptr = 0;
			if (block < start)
				ra_max = start - block;
			else
				ra_max = nblocks - block;
			ra_max = min(ra_max, ARRAY_SIZE(bh_use));
			retval = ext4_bread_batch(dir, block, ra_max,
						  false /* wait */, bh_use);
			if (retval) {
				ret = ERR_PTR(retval);
				ra_max = 0;
				goto cleanup_and_exit;
			}
		}
		if ((bh = bh_use[ra_ptr++]) == NULL)
			goto next;
		wait_on_buffer(bh);
		if (!buffer_uptodate(bh)) {
			EXT4_ERROR_INODE_ERR(dir, EIO,
					     "reading directory lblock %lu",
					     (unsigned long) block);
			brelse(bh);
			ret = ERR_PTR(-EIO);
			goto cleanup_and_exit;
		}
		if (!buffer_verified(bh) &&
		    !is_dx_internal_node(dir, block,
					 (struct ext4_dir_entry *)bh->b_data) &&
		    !ext4_dirblock_csum_verify(dir, bh)) {
			EXT4_ERROR_INODE_ERR(dir, EFSBADCRC,
					     "checksumming directory "
					     "block %lu", (unsigned long)block);
			brelse(bh);
			ret = ERR_PTR(-EFSBADCRC);
			goto cleanup_and_exit;
		}
		set_buffer_verified(bh);
		i = search_dirblock(bh, dir, fname,
			    block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
		if (i == 1) {
			EXT4_I(dir)->i_dir_start_lookup = block;
			ret = bh;
			goto cleanup_and_exit;
		} else {
			brelse(bh);
			if (i < 0)
				goto cleanup_and_exit;
		}
	next:
		if (++block >= nblocks)
			block = 0;
	} while (block != start);

	/*
	 * If the directory has grown while we were searching, then
	 * search the last part of the directory before giving up.
	 */
	block = nblocks;
	nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
	if (block < nblocks) {
		start = 0;
		goto restart;
	}

cleanup_and_exit:
	/* Clean up the read-ahead blocks */
	for (; ra_ptr < ra_max; ra_ptr++)
		brelse(bh_use[ra_ptr]);
	return ret;
}

ext4: fix potential negative array index in do_split()

If for any reason a directory passed to do_split() does not have enough
active entries to exceed half the size of the block, we can end up
iterating over all "count" entries without finding a split point.

In this case, count == move, and split will be zero, and we will
attempt a negative index into map[].

Guard against this by detecting this case, and falling back to
split-to-half-of-count instead; in this case we will still have
plenty of space (> half blocksize) in each split block.

Fixes: ef2b02d3e617 ("ext34: ensure do_split leaves enough free space in both blocks")
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/f53e246b-647c-64bb-16ec-135383c70ad7@redhat.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>


static void dx_sort_map (struct dx_map_entry *map, unsigned count)
{
	struct dx_map_entry *p, *q, *top = map + count - 1;
	int more;
	/* Combsort until bubble sort doesn't suck */
	while (count > 2) {
		count = count*10/13;
		if (count - 9 < 2) /* 9, 10 -> 11 */
			count = 11;
		for (p = top, q = p - count; q >= map; p--, q--)
			if (p->hash < q->hash)
				swap(*p, *q);
	}
	/* Garden variety bubble sort */
	do {
		more = 0;
		q = top;
		while (q-- > map) {
			if (q[1].hash >= q[0].hash)
				continue;
			swap(*(q+1), *q);
			more = 1;
		}
	} while(more);
}


static void ext4_inc_count(handle_t *handle, struct inode *inode)
{
	inc_nlink(inode);
	if (is_dx(inode) &&
	    (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2))
		set_nlink(inode, 1);
}


static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
{
	int retval;

	ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
					      &retval, &ent->parent_de,
					      &ent->dir_inlined);
	if (!ent->dir_bh)
		return retval;
	if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
		return -EFSCORRUPTED;
	BUFFER_TRACE(ent->dir_bh, "get_write_access");
	return ext4_journal_get_write_access(handle, ent->dir_bh);
}


static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
{
	handle_t *handle;
	struct inode *inode;
	int err, retries = 0;

	err = dquot_initialize(dir);
	if (err)
		return err;

retry:
	inode = ext4_new_inode_start_handle(dir, mode,
					    NULL, 0, NULL,
					    EXT4_HT_DIR,
			EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
			  4 + EXT4_XATTR_TRANS_BLOCKS);
	handle = ext4_journal_current_handle();
	err = PTR_ERR(inode);
	if (!IS_ERR(inode)) {
		inode->i_op = &ext4_file_inode_operations;
		inode->i_fop = &ext4_file_operations;
		ext4_set_aops(inode);
		d_tmpfile(dentry, inode);
		err = ext4_orphan_add(handle, inode);
		if (err)
			goto err_unlock_inode;
		mark_inode_dirty(inode);
		unlock_new_inode(inode);
	}
	if (handle)
		ext4_journal_stop(handle);
	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
		goto retry;
	return err;
err_unlock_inode:
	ext4_journal_stop(handle);
	unlock_new_inode(inode);
	return err;
}


static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
			       struct ext4_dir_entry *de)
{
	struct super_block *sb = dir->i_sb;

	if (!is_dx(dir))
		return 0;
	if (block == 0)
		return 1;
	if (de->inode == 0 &&
	    ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
			sb->s_blocksize)
		return 1;
	return 0;
}


static inline int ext4_handle_dirty_dx_node(handle_t *handle,
					    struct inode *inode,
					    struct buffer_head *bh)
{
	ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
	return ext4_handle_dirty_metadata(handle, inode, bh);
}


int ext4_find_dest_de(struct inode *dir, struct inode *inode,
		      struct buffer_head *bh,
		      void *buf, int buf_size,
		      struct ext4_filename *fname,
		      struct ext4_dir_entry_2 **dest_de)
{
	struct ext4_dir_entry_2 *de;
	unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
	int nlen, rlen;
	unsigned int offset = 0;
	char *top;

	de = (struct ext4_dir_entry_2 *)buf;
	top = buf + buf_size - reclen;
	while ((char *) de <= top) {
		if (ext4_check_dir_entry(dir, NULL, de, bh,
					 buf, buf_size, offset))
			return -EFSCORRUPTED;
		if (ext4_match(dir, fname, de))
			return -EEXIST;
		nlen = EXT4_DIR_REC_LEN(de->name_len);
		rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
		if ((de->inode ? rlen - nlen : rlen) >= reclen)
			break;
		de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
		offset += rlen;
	}
	if ((char *) de > top)
		return -ENOSPC;

	*dest_de = de;
	return 0;
}


static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
			     struct inode *dir, struct inode *inode)
{
	struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
	struct dx_entry *entries, *at;
	struct buffer_head *bh;
	struct super_block *sb = dir->i_sb;
	struct ext4_dir_entry_2 *de;
	int restart;
	int err;

again:
	restart = 0;
	frame = dx_probe(fname, dir, NULL, frames);
	if (IS_ERR(frame))
		return PTR_ERR(frame);
	entries = frame->entries;
	at = frame->at;
	bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT_HTREE);
	if (IS_ERR(bh)) {
		err = PTR_ERR(bh);
		bh = NULL;
		goto cleanup;
	}

	BUFFER_TRACE(bh, "get_write_access");
	err = ext4_journal_get_write_access(handle, bh);
	if (err)
		goto journal_error;

	err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
	if (err != -ENOSPC)
		goto cleanup;

	err = 0;
	/* Block full, should compress but for now just split */
	dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
		       dx_get_count(entries), dx_get_limit(entries)));
	/* Need to split index? */
	if (dx_get_count(entries) == dx_get_limit(entries)) {
		ext4_lblk_t newblock;
		int levels = frame - frames + 1;
		unsigned int icount;
		int add_level = 1;
		struct dx_entry *entries2;
		struct dx_node *node2;
		struct buffer_head *bh2;

		while (frame > frames) {
			if (dx_get_count((frame - 1)->entries) <
			    dx_get_limit((frame - 1)->entries)) {
				add_level = 0;
				break;
			}
			frame--; /* split higher index block */
			at = frame->at;
			entries = frame->entries;
			restart = 1;
		}
		if (add_level && levels == ext4_dir_htree_level(sb)) {
			ext4_warning(sb, "Directory (ino: %lu) index full, "
					 "reach max htree level :%d",
					 dir->i_ino, levels);
			if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) {
				ext4_warning(sb, "Large directory feature is "
						 "not enabled on this "
						 "filesystem");
			}
			err = -ENOSPC;
			goto cleanup;
		}
		icount = dx_get_count(entries);
		bh2 = ext4_append(handle, dir, &newblock);
		if (IS_ERR(bh2)) {
			err = PTR_ERR(bh2);
			goto cleanup;
		}
		node2 = (struct dx_node *)(bh2->b_data);
		entries2 = node2->entries;
		memset(&node2->fake, 0, sizeof(struct fake_dirent));
		node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
							   sb->s_blocksize);
		BUFFER_TRACE(frame->bh, "get_write_access");
		err = ext4_journal_get_write_access(handle, frame->bh);
		if (err)
			goto journal_error;
		if (!add_level) {
			unsigned icount1 = icount/2, icount2 = icount - icount1;
			unsigned hash2 = dx_get_hash(entries + icount1);
			dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
				       icount1, icount2));

			BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
			err = ext4_journal_get_write_access(handle,
							     (frame - 1)->bh);
			if (err)
				goto journal_error;

			memcpy((char *) entries2, (char *) (entries + icount1),
			       icount2 * sizeof(struct dx_entry));
			dx_set_count(entries, icount1);
			dx_set_count(entries2, icount2);
			dx_set_limit(entries2, dx_node_limit(dir));

			/* Which index block gets the new entry? */
			if (at - entries >= icount1) {
				frame->at = at = at - entries - icount1 + entries2;
				frame->entries = entries = entries2;
				swap(frame->bh, bh2);
			}
			dx_insert_block((frame - 1), hash2, newblock);
			dxtrace(dx_show_index("node", frame->entries));
			dxtrace(dx_show_index("node",
			       ((struct dx_node *) bh2->b_data)->entries));
			err = ext4_handle_dirty_dx_node(handle, dir, bh2);
			if (err)
				goto journal_error;
			brelse (bh2);
			err = ext4_handle_dirty_dx_node(handle, dir,
						   (frame - 1)->bh);
			if (err)
				goto journal_error;
			if (restart) {
				err = ext4_handle_dirty_dx_node(handle, dir,
							   frame->bh);
				goto journal_error;
			}
		} else {
			struct dx_root *dxroot;
			memcpy((char *) entries2, (char *) entries,
			       icount * sizeof(struct dx_entry));
			dx_set_limit(entries2, dx_node_limit(dir));

			/* Set up root */
			dx_set_count(entries, 1);
			dx_set_block(entries + 0, newblock);
			dxroot = (struct dx_root *)frames[0].bh->b_data;
			dxroot->info.indirect_levels += 1;
			dxtrace(printk(KERN_DEBUG
				       "Creating %d level index...\n",
				       dxroot->info.indirect_levels));
			err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
			if (err)
				goto journal_error;
			err = ext4_handle_dirty_dx_node(handle, dir, bh2);
			brelse(bh2);
			restart = 1;
			goto journal_error;
		}
	}
	de = do_split(handle, dir, &bh, frame, &fname->hinfo);
	if (IS_ERR(de)) {
		err = PTR_ERR(de);
		goto cleanup;
	}
	err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
	goto cleanup;

journal_error:
	ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */
cleanup:
	brelse(bh);
	dx_release(frames);
	/* @restart is true means htree-path has been changed, we need to
	 * repeat dx_probe() to find out valid htree-path
	 */
	if (restart && err == 0)
		goto again;
	return err;
}


static int ext4_link(struct dentry *old_dentry,
		     struct inode *dir, struct dentry *dentry)
{
	handle_t *handle;
	struct inode *inode = d_inode(old_dentry);
	int err, retries = 0;

	if (inode->i_nlink >= EXT4_LINK_MAX)
		return -EMLINK;

	err = fscrypt_prepare_link(old_dentry, dir, dentry);
	if (err)
		return err;

	if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
	    (!projid_eq(EXT4_I(dir)->i_projid,
			EXT4_I(old_dentry->d_inode)->i_projid)))
		return -EXDEV;

	err = dquot_initialize(dir);
	if (err)
		return err;

retry:
	handle = ext4_journal_start(dir, EXT4_HT_DIR,
		(EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
		 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
	if (IS_ERR(handle))
		return PTR_ERR(handle);

	if (IS_DIRSYNC(dir))
		ext4_handle_sync(handle);

	inode->i_ctime = current_time(inode);
	ext4_inc_count(handle, inode);
	ihold(inode);

	err = ext4_add_entry(handle, dentry, inode);
	if (!err) {
		err = ext4_mark_inode_dirty(handle, inode);
		/* this can happen only for tmpfile being
		 * linked the first time
		 */
		if (inode->i_nlink == 1)
			ext4_orphan_del(handle, inode);
		d_instantiate(dentry, inode);
	} else {
		drop_nlink(inode);
		iput(inode);
	}
	ext4_journal_stop(handle);
	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
		goto retry;
	return err;
}


static struct buffer_head *ext4_lookup_entry(struct inode *dir,
					     struct dentry *dentry,
					     struct ext4_dir_entry_2 **res_dir)
{
	int err;
	struct ext4_filename fname;
	struct buffer_head *bh;

	err = ext4_fname_prepare_lookup(dir, dentry, &fname);
	if (err == -ENOENT)
		return NULL;
	if (err)
		return ERR_PTR(err);

	bh = __ext4_find_entry(dir, &fname, res_dir, NULL);

	ext4_fname_free_filename(&fname);
	return bh;
}


static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
{
	return le32_to_cpu(entry->block) & 0x0fffffff;
}


dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
		unsigned blocksize)
{
	unsigned rec_len = 0;

	while (count--) {
		struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
						(from + (map->offs<<2));
		rec_len = EXT4_DIR_REC_LEN(de->name_len);
		memcpy (to, de, rec_len);
		((struct ext4_dir_entry_2 *) to)->rec_len =
				ext4_rec_len_to_disk(rec_len, blocksize);
		de->inode = 0;
		map++;
		to += rec_len;
	}
	return (struct ext4_dir_entry_2 *) (to - rec_len);
}


struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
			     struct dx_entry *entries, int levels)
{
	unsigned blocksize = dir->i_sb->s_blocksize;
	unsigned count = dx_get_count(entries), names = 0, space = 0, i;
	unsigned bcount = 0;
	struct buffer_head *bh;
	printk("%i indexed blocks...\n", count);
	for (i = 0; i < count; i++, entries++)
	{
		ext4_lblk_t block = dx_get_block(entries);
		ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
		u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
		struct stats stats;
		printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
		bh = ext4_bread(NULL,dir, block, 0);
		if (!bh || IS_ERR(bh))
			continue;
		stats = levels?
		   dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
		   dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
			bh->b_data, blocksize, 0);
		names += stats.names;
		space += stats.space;
		bcount += stats.bcount;
		brelse(bh);
	}
	if (bcount)
		printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
		       levels ? "" : "   ", names, space/bcount,
		       (space/bcount)*100/blocksize);
	return (struct stats) { names, space, bcount};
}


static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
			     struct inode *inode)
{
	struct buffer_head *dir_block = NULL;
	struct ext4_dir_entry_2 *de;
	ext4_lblk_t block = 0;
	unsigned int blocksize = dir->i_sb->s_blocksize;
	int csum_size = 0;
	int err;

	if (ext4_has_metadata_csum(dir->i_sb))
		csum_size = sizeof(struct ext4_dir_entry_tail);

	if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
		err = ext4_try_create_inline_dir(handle, dir, inode);
		if (err < 0 && err != -ENOSPC)
			goto out;
		if (!err)
			goto out;
	}

	inode->i_size = 0;
	dir_block = ext4_append(handle, inode, &block);
	if (IS_ERR(dir_block))
		return PTR_ERR(dir_block);
	de = (struct ext4_dir_entry_2 *)dir_block->b_data;
	ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
	set_nlink(inode, 2);
	if (csum_size)
		ext4_initialize_dirent_tail(dir_block, blocksize);

	BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
	err = ext4_handle_dirty_dirblock(handle, inode, dir_block);
	if (err)
		goto out;
	set_buffer_verified(dir_block);
out:
	brelse(dir_block);
	return err;
}


static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
					       struct ext4_dir_entry *dirent,
					       int *offset)
{
	struct ext4_dir_entry *dp;
	struct dx_root_info *root;
	int count_offset;

	if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
		count_offset = 8;
	else if (le16_to_cpu(dirent->rec_len) == 12) {
		dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
		if (le16_to_cpu(dp->rec_len) !=
		    EXT4_BLOCK_SIZE(inode->i_sb) - 12)
			return NULL;
		root = (struct dx_root_info *)(((void *)dp + 12));
		if (root->reserved_zero ||
		    root->info_length != sizeof(struct dx_root_info))
			return NULL;
		count_offset = 32;
	} else
		return NULL;

	if (offset)
		*offset = count_offset;
	return (struct dx_countlimit *)(((void *)dirent) + count_offset);
}


static int htree_dirblock_to_tree(struct file *dir_file,
				  struct inode *dir, ext4_lblk_t block,
				  struct dx_hash_info *hinfo,
				  __u32 start_hash, __u32 start_minor_hash)
{
	struct buffer_head *bh;
	struct ext4_dir_entry_2 *de, *top;
	int err = 0, count = 0;
	struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str;

	dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
							(unsigned long)block));
	bh = ext4_read_dirblock(dir, block, DIRENT_HTREE);
	if (IS_ERR(bh))
		return PTR_ERR(bh);

	de = (struct ext4_dir_entry_2 *) bh->b_data;
	top = (struct ext4_dir_entry_2 *) ((char *) de +
					   dir->i_sb->s_blocksize -
					   EXT4_DIR_REC_LEN(0));
	/* Check if the directory is encrypted */
	if (IS_ENCRYPTED(dir)) {
		err = fscrypt_get_encryption_info(dir);
		if (err < 0) {
			brelse(bh);
			return err;
		}
		err = fscrypt_fname_alloc_buffer(dir, EXT4_NAME_LEN,
						     &fname_crypto_str);
		if (err < 0) {
			brelse(bh);
			return err;
		}
	}

	for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
		if (ext4_check_dir_entry(dir, NULL, de, bh,
				bh->b_data, bh->b_size,
				(block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
					 + ((char *)de - bh->b_data))) {
			/* silently ignore the rest of the block */
			break;
		}
		ext4fs_dirhash(dir, de->name, de->name_len, hinfo);
		if ((hinfo->hash < start_hash) ||
		    ((hinfo->hash == start_hash) &&
		     (hinfo->minor_hash < start_minor_hash)))
			continue;
		if (de->inode == 0)
			continue;
		if (!IS_ENCRYPTED(dir)) {
			tmp_str.name = de->name;
			tmp_str.len = de->name_len;
			err = ext4_htree_store_dirent(dir_file,
				   hinfo->hash, hinfo->minor_hash, de,
				   &tmp_str);
		} else {
			int save_len = fname_crypto_str.len;
			struct fscrypt_str de_name = FSTR_INIT(de->name,
								de->name_len);

			/* Directory is encrypted */
			err = fscrypt_fname_disk_to_usr(dir, hinfo->hash,
					hinfo->minor_hash, &de_name,
					&fname_crypto_str);
			if (err) {
				count = err;
				goto errout;
			}
			err = ext4_htree_store_dirent(dir_file,
				   hinfo->hash, hinfo->minor_hash, de,
					&fname_crypto_str);
			fname_crypto_str.len = save_len;
		}
		if (err != 0) {
			count = err;
			goto errout;
		}
		count++;
	}
errout:
	brelse(bh);
	fscrypt_fname_free_buffer(&fname_crypto_str);
	return count;
}


static void ext4_dirblock_csum_set(struct inode *inode,
				 struct buffer_head *bh)
{
	struct ext4_dir_entry_tail *t;

	if (!ext4_has_metadata_csum(inode->i_sb))
		return;

	t = get_dirent_tail(inode, bh);
	if (!t) {
		warn_no_space_for_csum(inode);
		return;
	}

	t->det_checksum = ext4_dirblock_csum(inode, bh->b_data,
					     (char *)t - bh->b_data);
}


static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
			       int force_reread)
{
	int retval;
	/*
	 * ent->de could have moved from under us during htree split, so make
	 * sure that we are deleting the right entry.  We might also be pointing
	 * to a stale entry in the unused part of ent->bh so just checking inum
	 * and the name isn't enough.
	 */
	if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
	    ent->de->name_len != ent->dentry->d_name.len ||
	    strncmp(ent->de->name, ent->dentry->d_name.name,
		    ent->de->name_len) ||
	    force_reread) {
		retval = ext4_find_delete_entry(handle, ent->dir,
						&ent->dentry->d_name);
	} else {
		retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
		if (retval == -ENOENT) {
			retval = ext4_find_delete_entry(handle, ent->dir,
							&ent->dentry->d_name);
		}
	}

	if (retval) {
		ext4_warning_inode(ent->dir,
				   "Deleting old file: nlink %d, error=%d",
				   ent->dir->i_nlink, retval);
	}
}


int ext4_generic_delete_entry(handle_t *handle,
			      struct inode *dir,
			      struct ext4_dir_entry_2 *de_del,
			      struct buffer_head *bh,
			      void *entry_buf,
			      int buf_size,
			      int csum_size)
{
	struct ext4_dir_entry_2 *de, *pde;
	unsigned int blocksize = dir->i_sb->s_blocksize;
	int i;

	i = 0;
	pde = NULL;
	de = (struct ext4_dir_entry_2 *)entry_buf;
	while (i < buf_size - csum_size) {
		if (ext4_check_dir_entry(dir, NULL, de, bh,
					 bh->b_data, bh->b_size, i))
			return -EFSCORRUPTED;
		if (de == de_del)  {
			if (pde)
				pde->rec_len = ext4_rec_len_to_disk(
					ext4_rec_len_from_disk(pde->rec_len,
							       blocksize) +
					ext4_rec_len_from_disk(de->rec_len,
							       blocksize),
					blocksize);
			else
				de->inode = 0;
			inode_inc_iversion(dir);
			return 0;
		}
		i += ext4_rec_len_from_disk(de->rec_len, blocksize);
		pde = de;
		de = ext4_next_entry(de, blocksize);
	}
	return -ENOENT;
}


dx_probe(struct ext4_filename *fname, struct inode *dir,
	 struct dx_hash_info *hinfo, struct dx_frame *frame_in)
{
	unsigned count, indirect;
	struct dx_entry *at, *entries, *p, *q, *m;
	struct dx_root *root;
	struct dx_frame *frame = frame_in;
	struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
	u32 hash;

	memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0]));
	frame->bh = ext4_read_dirblock(dir, 0, INDEX);
	if (IS_ERR(frame->bh))
		return (struct dx_frame *) frame->bh;

	root = (struct dx_root *) frame->bh->b_data;
	if (root->info.hash_version != DX_HASH_TEA &&
	    root->info.hash_version != DX_HASH_HALF_MD4 &&
	    root->info.hash_version != DX_HASH_LEGACY) {
		ext4_warning_inode(dir, "Unrecognised inode hash code %u",
				   root->info.hash_version);
		goto fail;
	}
	if (fname)
		hinfo = &fname->hinfo;
	hinfo->hash_version = root->info.hash_version;
	if (hinfo->hash_version <= DX_HASH_TEA)
		hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
	hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
	if (fname && fname_name(fname))
		ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), hinfo);
	hash = hinfo->hash;

	if (root->info.unused_flags & 1) {
		ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
				   root->info.unused_flags);
		goto fail;
	}

	indirect = root->info.indirect_levels;
	if (indirect >= ext4_dir_htree_level(dir->i_sb)) {
		ext4_warning(dir->i_sb,
			     "Directory (ino: %lu) htree depth %#06x exceed"
			     "supported value", dir->i_ino,
			     ext4_dir_htree_level(dir->i_sb));
		if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) {
			ext4_warning(dir->i_sb, "Enable large directory "
						"feature to access it");
		}
		goto fail;
	}

	entries = (struct dx_entry *)(((char *)&root->info) +
				      root->info.info_length);

	if (dx_get_limit(entries) != dx_root_limit(dir,
						   root->info.info_length)) {
		ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
				   dx_get_limit(entries),
				   dx_root_limit(dir, root->info.info_length));
		goto fail;
	}

	dxtrace(printk("Look up %x", hash));
	while (1) {
		count = dx_get_count(entries);
		if (!count || count > dx_get_limit(entries)) {
			ext4_warning_inode(dir,
					   "dx entry: count %u beyond limit %u",
					   count, dx_get_limit(entries));
			goto fail;
		}

		p = entries + 1;
		q = entries + count - 1;
		while (p <= q) {
			m = p + (q - p) / 2;
			dxtrace(printk(KERN_CONT "."));
			if (dx_get_hash(m) > hash)
				q = m - 1;
			else
				p = m + 1;
		}

		if (0) { // linear search cross check
			unsigned n = count - 1;
			at = entries;
			while (n--)
			{
				dxtrace(printk(KERN_CONT ","));
				if (dx_get_hash(++at) > hash)
				{
					at--;
					break;
				}
			}
			assert (at == p - 1);
		}

		at = p - 1;
		dxtrace(printk(KERN_CONT " %x->%u\n",
			       at == entries ? 0 : dx_get_hash(at),
			       dx_get_block(at)));
		frame->entries = entries;
		frame->at = at;
		if (!indirect--)
			return frame;
		frame++;
		frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX);
		if (IS_ERR(frame->bh)) {
			ret_err = (struct dx_frame *) frame->bh;
			frame->bh = NULL;
			goto fail;
		}
		entries = ((struct dx_node *) frame->bh->b_data)->entries;

		if (dx_get_limit(entries) != dx_node_limit(dir)) {
			ext4_warning_inode(dir,
				"dx entry: limit %u != node limit %u",
				dx_get_limit(entries), dx_node_limit(dir));
			goto fail;
		}
	}
fail:
	while (frame >= frame_in) {
		brelse(frame->bh);
		frame--;
	}

	if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
		ext4_warning_inode(dir,
			"Corrupt directory, running e2fsck is recommended");
	return ret_err;
}


int ext4_orphan_del(handle_t *handle, struct inode *inode)
{
	struct list_head *prev;
	struct ext4_inode_info *ei = EXT4_I(inode);
	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
	__u32 ino_next;
	struct ext4_iloc iloc;
	int err = 0;

	if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS))
		return 0;

	WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
		     !inode_is_locked(inode));
	/* Do this quick check before taking global s_orphan_lock. */
	if (list_empty(&ei->i_orphan))
		return 0;

	if (handle) {
		/* Grab inode buffer early before taking global s_orphan_lock */
		err = ext4_reserve_inode_write(handle, inode, &iloc);
	}

	mutex_lock(&sbi->s_orphan_lock);
	jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);

	prev = ei->i_orphan.prev;
	list_del_init(&ei->i_orphan);

	/* If we're on an error path, we may not have a valid
	 * transaction handle with which to update the orphan list on
	 * disk, but we still need to remove the inode from the linked
	 * list in memory. */
	if (!handle || err) {
		mutex_unlock(&sbi->s_orphan_lock);
		goto out_err;
	}

	ino_next = NEXT_ORPHAN(inode);
	if (prev == &sbi->s_orphan) {
		jbd_debug(4, "superblock will point to %u\n", ino_next);
		BUFFER_TRACE(sbi->s_sbh, "get_write_access");
		err = ext4_journal_get_write_access(handle, sbi->s_sbh);
		if (err) {
			mutex_unlock(&sbi->s_orphan_lock);
			goto out_brelse;
		}
		sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
		mutex_unlock(&sbi->s_orphan_lock);
		err = ext4_handle_dirty_super(handle, inode->i_sb);
	} else {
		struct ext4_iloc iloc2;
		struct inode *i_prev =
			&list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;

		jbd_debug(4, "orphan inode %lu will point to %u\n",
			  i_prev->i_ino, ino_next);
		err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
		if (err) {
			mutex_unlock(&sbi->s_orphan_lock);
			goto out_brelse;
		}
		NEXT_ORPHAN(i_prev) = ino_next;
		err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
		mutex_unlock(&sbi->s_orphan_lock);
	}
	if (err)
		goto out_brelse;
	NEXT_ORPHAN(inode) = 0;
	err = ext4_mark_iloc_dirty(handle, inode, &iloc);
out_err:
	ext4_std_error(inode->i_sb, err);
	return err;

out_brelse:
	brelse(iloc.bh);
	goto out_err;
}


static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
						ext4_lblk_t block,
						dirblock_type_t type,
						const char *func,
						unsigned int line)
{
	struct buffer_head *bh;
	struct ext4_dir_entry *dirent;
	int is_dx_block = 0;

	if (ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_EIO))
		bh = ERR_PTR(-EIO);
	else
		bh = ext4_bread(NULL, inode, block, 0);
	if (IS_ERR(bh)) {
		__ext4_warning(inode->i_sb, func, line,
			       "inode #%lu: lblock %lu: comm %s: "
			       "error %ld reading directory block",
			       inode->i_ino, (unsigned long)block,
			       current->comm, PTR_ERR(bh));

		return bh;
	}
	if (!bh && (type == INDEX || type == DIRENT_HTREE)) {
		ext4_error_inode(inode, func, line, block,
				 "Directory hole found for htree %s block",
				 (type == INDEX) ? "index" : "leaf");
		return ERR_PTR(-EFSCORRUPTED);
	}
	if (!bh)
		return NULL;
	dirent = (struct ext4_dir_entry *) bh->b_data;
	/* Determine whether or not we have an index block */
	if (is_dx(inode)) {
		if (block == 0)
			is_dx_block = 1;
		else if (ext4_rec_len_from_disk(dirent->rec_len,
						inode->i_sb->s_blocksize) ==
			 inode->i_sb->s_blocksize)
			is_dx_block = 1;
	}
	if (!is_dx_block && type == INDEX) {
		ext4_error_inode(inode, func, line, block,
		       "directory leaf block found instead of index block");
		brelse(bh);
		return ERR_PTR(-EFSCORRUPTED);
	}
	if (!ext4_has_metadata_csum(inode->i_sb) ||
	    buffer_verified(bh))
		return bh;

	/*
	 * An empty leaf block can get mistaken for a index block; for
	 * this reason, we can only check the index checksum when the
	 * caller is sure it should be an index block.
	 */
	if (is_dx_block && type == INDEX) {
		if (ext4_dx_csum_verify(inode, dirent) &&
		    !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC))
			set_buffer_verified(bh);
		else {
			ext4_error_inode_err(inode, func, line, block,
					     EFSBADCRC,
					     "Directory index failed checksum");
			brelse(bh);
			return ERR_PTR(-EFSBADCRC);
		}
	}
	if (!is_dx_block) {
		if (ext4_dirblock_csum_verify(inode, bh) &&
		    !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC))
			set_buffer_verified(bh);
		else {
			ext4_error_inode_err(inode, func, line, block,
					     EFSBADCRC,
					     "Directory block failed checksum");
			brelse(bh);
			return ERR_PTR(-EFSBADCRC);
		}
	}
	return bh;
}


static inline bool ext4_match(const struct inode *parent,
			      const struct ext4_filename *fname,
			      const struct ext4_dir_entry_2 *de)
{
	struct fscrypt_name f;
#ifdef CONFIG_UNICODE
	const struct qstr entry = {.name = de->name, .len = de->name_len};
#endif

	if (!de->inode)
		return false;

	f.usr_fname = fname->usr_fname;
	f.disk_name = fname->disk_name;
#ifdef CONFIG_FS_ENCRYPTION
	f.crypto_buf = fname->crypto_buf;
#endif

#ifdef CONFIG_UNICODE
	if (EXT4_SB(parent->i_sb)->s_encoding && IS_CASEFOLDED(parent)) {
		if (fname->cf_name.name) {
			struct qstr cf = {.name = fname->cf_name.name,
					  .len = fname->cf_name.len};
			return !ext4_ci_compare(parent, &cf, &entry, true);
		}
		return !ext4_ci_compare(parent, fname->usr_fname, &entry,
					false);
	}
#endif

	return fscrypt_match_name(&f, de->name, de->name_len);
}


struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
			  struct ext4_dir_entry_2 *de,
			  int blocksize, int csum_size,
			  unsigned int parent_ino, int dotdot_real_len)
{
	de->inode = cpu_to_le32(inode->i_ino);
	de->name_len = 1;
	de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
					   blocksize);
	strcpy(de->name, ".");
	ext4_set_de_type(inode->i_sb, de, S_IFDIR);

	de = ext4_next_entry(de, blocksize);
	de->inode = cpu_to_le32(parent_ino);
	de->name_len = 2;
	if (!dotdot_real_len)
		de->rec_len = ext4_rec_len_to_disk(blocksize -
					(csum_size + EXT4_DIR_REC_LEN(1)),
					blocksize);
	else
		de->rec_len = ext4_rec_len_to_disk(
				EXT4_DIR_REC_LEN(de->name_len), blocksize);
	strcpy(de->name, "..");
	ext4_set_de_type(inode->i_sb, de, S_IFDIR);

	return ext4_next_entry(de, blocksize);
}


int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
		    struct inode *dir, struct ext4_filename *fname,
		    unsigned int offset, struct ext4_dir_entry_2 **res_dir)
{
	struct ext4_dir_entry_2 * de;
	char * dlimit;
	int de_len;

	de = (struct ext4_dir_entry_2 *)search_buf;
	dlimit = search_buf + buf_size;
	while ((char *) de < dlimit) {
		/* this code is executed quadratically often */
		/* do minimal checking `by hand' */
		if ((char *) de + de->name_len <= dlimit &&
		    ext4_match(dir, fname, de)) {
			/* found a match - just to be sure, do
			 * a full check */
			if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data,
						 bh->b_size, offset))
				return -1;
			*res_dir = de;
			return 1;
		}
		/* prevent looping on a bad block */
		de_len = ext4_rec_len_from_disk(de->rec_len,
						dir->i_sb->s_blocksize);
		if (de_len <= 0)
			return -1;
		offset += de_len;
		de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
	}
	return 0;
}


static int ext4_htree_next_block(struct inode *dir, __u32 hash,
				 struct dx_frame *frame,
				 struct dx_frame *frames,
				 __u32 *start_hash)
{
	struct dx_frame *p;
	struct buffer_head *bh;
	int num_frames = 0;
	__u32 bhash;

	p = frame;
	/*
	 * Find the next leaf page by incrementing the frame pointer.
	 * If we run out of entries in the interior node, loop around and
	 * increment pointer in the parent node.  When we break out of
	 * this loop, num_frames indicates the number of interior
	 * nodes need to be read.
	 */
	while (1) {
		if (++(p->at) < p->entries + dx_get_count(p->entries))
			break;
		if (p == frames)
			return 0;
		num_frames++;
		p--;
	}

	/*
	 * If the hash is 1, then continue only if the next page has a
	 * continuation hash of any value.  This is used for readdir
	 * handling.  Otherwise, check to see if the hash matches the
	 * desired contiuation hash.  If it doesn't, return since
	 * there's no point to read in the successive index pages.
	 */
	bhash = dx_get_hash(p->at);
	if (start_hash)
		*start_hash = bhash;
	if ((hash & 1) == 0) {
		if ((bhash & ~1) != hash)
			return 0;
	}
	/*
	 * If the hash is HASH_NB_ALWAYS, we always go to the next
	 * block so no check is necessary
	 */
	while (num_frames--) {
		bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
		if (IS_ERR(bh))
			return PTR_ERR(bh);
		p++;
		brelse(p->bh);
		p->bh = bh;
		p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
	}
	return 1;
}


static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
				  const struct qstr *d_name)
{
	int retval = -ENOENT;
	struct buffer_head *bh;
	struct ext4_dir_entry_2 *de;

	bh = ext4_find_entry(dir, d_name, &de, NULL);
	if (IS_ERR(bh))
		return PTR_ERR(bh);
	if (bh) {
		retval = ext4_delete_entry(handle, dir, de, bh);
		brelse(bh);
	}
	return retval;
}


static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
{
	entry->block = cpu_to_le32(value);
}


static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
			struct buffer_head **bh,struct dx_frame *frame,
			struct dx_hash_info *hinfo)
{
	unsigned blocksize = dir->i_sb->s_blocksize;
	unsigned count, continued;
	struct buffer_head *bh2;
	ext4_lblk_t newblock;
	u32 hash2;
	struct dx_map_entry *map;
	char *data1 = (*bh)->b_data, *data2;
	unsigned split, move, size;
	struct ext4_dir_entry_2 *de = NULL, *de2;
	int	csum_size = 0;
	int	err = 0, i;

	if (ext4_has_metadata_csum(dir->i_sb))
		csum_size = sizeof(struct ext4_dir_entry_tail);

	bh2 = ext4_append(handle, dir, &newblock);
	if (IS_ERR(bh2)) {
		brelse(*bh);
		*bh = NULL;
		return (struct ext4_dir_entry_2 *) bh2;
	}

	BUFFER_TRACE(*bh, "get_write_access");
	err = ext4_journal_get_write_access(handle, *bh);
	if (err)
		goto journal_error;

	BUFFER_TRACE(frame->bh, "get_write_access");
	err = ext4_journal_get_write_access(handle, frame->bh);
	if (err)
		goto journal_error;

	data2 = bh2->b_data;

	/* create map in the end of data2 block */
	map = (struct dx_map_entry *) (data2 + blocksize);
	count = dx_make_map(dir, (struct ext4_dir_entry_2 *) data1,
			     blocksize, hinfo, map);
	map -= count;
	dx_sort_map(map, count);
	/* Ensure that neither split block is over half full */
	size = 0;
	move = 0;
	for (i = count-1; i >= 0; i--) {
		/* is more than half of this entry in 2nd half of the block? */
		if (size + map[i].size/2 > blocksize/2)
			break;
		size += map[i].size;
		move++;
	}
	/*
	 * map index at which we will split
	 *
	 * If the sum of active entries didn't exceed half the block size, just
	 * split it in half by count; each resulting block will have at least
	 * half the space free.
	 */
	if (i > 0)
		split = count - move;
	else
		split = count/2;

	hash2 = map[split].hash;
	continued = hash2 == map[split - 1].hash;
	dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
			(unsigned long)dx_get_block(frame->at),
					hash2, split, count-split));

	/* Fancy dance to stay within two buffers */
	de2 = dx_move_dirents(data1, data2, map + split, count - split,
			      blocksize);
	de = dx_pack_dirents(data1, blocksize);
	de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
					   (char *) de,
					   blocksize);
	de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
					    (char *) de2,
					    blocksize);
	if (csum_size) {
		ext4_initialize_dirent_tail(*bh, blocksize);
		ext4_initialize_dirent_tail(bh2, blocksize);
	}

	dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
			blocksize, 1));
	dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
			blocksize, 1));

	/* Which block gets the new entry? */
	if (hinfo->hash >= hash2) {
		swap(*bh, bh2);
		de = de2;
	}
	dx_insert_block(frame, hash2 + continued, newblock);
	err = ext4_handle_dirty_dirblock(handle, dir, bh2);
	if (err)
		goto journal_error;
	err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
	if (err)
		goto journal_error;
	brelse(bh2);
	dxtrace(dx_show_index("frame", frame->entries));
	return de;

journal_error:
	brelse(*bh);
	brelse(bh2);
	*bh = NULL;
	ext4_std_error(dir->i_sb, err);
	return ERR_PTR(err);
}


static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
{
	if (ent->dir_nlink_delta) {
		if (ent->dir_nlink_delta == -1)
			ext4_dec_count(handle, ent->dir);
		else
			ext4_inc_count(handle, ent->dir);
		ext4_mark_inode_dirty(handle, ent->dir);
	}
}


int ext4_dirblock_csum_verify(struct inode *inode, struct buffer_head *bh)
{
	struct ext4_dir_entry_tail *t;

	if (!ext4_has_metadata_csum(inode->i_sb))
		return 1;

	t = get_dirent_tail(inode, bh);
	if (!t) {
		warn_no_space_for_csum(inode);
		return 0;
	}

	if (t->det_checksum != ext4_dirblock_csum(inode, bh->b_data,
						  (char *)t - bh->b_data))
		return 0;

	return 1;
}


static int ext4_unlink(struct inode *dir, struct dentry *dentry)
{
	int retval;
	struct inode *inode;
	struct buffer_head *bh;
	struct ext4_dir_entry_2 *de;
	handle_t *handle = NULL;

	if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
		return -EIO;

	trace_ext4_unlink_enter(dir, dentry);
	/* Initialize quotas before so that eventual writes go
	 * in separate transaction */
	retval = dquot_initialize(dir);
	if (retval)
		return retval;
	retval = dquot_initialize(d_inode(dentry));
	if (retval)
		return retval;

	retval = -ENOENT;
	bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
	if (IS_ERR(bh))
		return PTR_ERR(bh);
	if (!bh)
		goto end_unlink;

	inode = d_inode(dentry);

	retval = -EFSCORRUPTED;
	if (le32_to_cpu(de->inode) != inode->i_ino)
		goto end_unlink;

	handle = ext4_journal_start(dir, EXT4_HT_DIR,
				    EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
	if (IS_ERR(handle)) {
		retval = PTR_ERR(handle);
		handle = NULL;
		goto end_unlink;
	}

	if (IS_DIRSYNC(dir))
		ext4_handle_sync(handle);

	retval = ext4_delete_entry(handle, dir, de, bh);
	if (retval)
		goto end_unlink;
	dir->i_ctime = dir->i_mtime = current_time(dir);
	ext4_update_dx_flag(dir);
	retval = ext4_mark_inode_dirty(handle, dir);
	if (retval)
		goto end_unlink;
	if (inode->i_nlink == 0)
		ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
				   dentry->d_name.len, dentry->d_name.name);
	else
		drop_nlink(inode);
	if (!inode->i_nlink)
		ext4_orphan_add(handle, inode);
	inode->i_ctime = current_time(inode);
	retval = ext4_mark_inode_dirty(handle, inode);

#ifdef CONFIG_UNICODE
	/* VFS negative dentries are incompatible with Encoding and
	 * Case-insensitiveness. Eventually we'll want avoid
	 * invalidating the dentries here, alongside with returning the
	 * negative dentries at ext4_lookup(), when it is  better
	 * supported by the VFS for the CI case.
	 */
	if (IS_CASEFOLDED(dir))
		d_invalidate(dentry);
#endif

end_unlink:
	brelse(bh);
	if (handle)
		ext4_journal_stop(handle);
	trace_ext4_unlink_exit(dentry, retval);
	return retval;
}


bool ext4_empty_dir(struct inode *inode)
{
	unsigned int offset;
	struct buffer_head *bh;
	struct ext4_dir_entry_2 *de;
	struct super_block *sb;

	if (ext4_has_inline_data(inode)) {
		int has_inline_data = 1;
		int ret;

		ret = empty_inline_dir(inode, &has_inline_data);
		if (has_inline_data)
			return ret;
	}

	sb = inode->i_sb;
	if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
		EXT4_ERROR_INODE(inode, "invalid size");
		return true;
	}
	/* The first directory block must not be a hole,
	 * so treat it as DIRENT_HTREE
	 */
	bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);
	if (IS_ERR(bh))
		return true;

	de = (struct ext4_dir_entry_2 *) bh->b_data;
	if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
				 0) ||
	    le32_to_cpu(de->inode) != inode->i_ino || strcmp(".", de->name)) {
		ext4_warning_inode(inode, "directory missing '.'");
		brelse(bh);
		return true;
	}
	offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
	de = ext4_next_entry(de, sb->s_blocksize);
	if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
				 offset) ||
	    le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) {
		ext4_warning_inode(inode, "directory missing '..'");
		brelse(bh);
		return true;
	}
	offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
	while (offset < inode->i_size) {
		if (!(offset & (sb->s_blocksize - 1))) {
			unsigned int lblock;
			brelse(bh);
			lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
			bh = ext4_read_dirblock(inode, lblock, EITHER);
			if (bh == NULL) {
				offset += sb->s_blocksize;
				continue;
			}
			if (IS_ERR(bh))
				return true;
		}
		de = (struct ext4_dir_entry_2 *) (bh->b_data +
					(offset & (sb->s_blocksize - 1)));
		if (ext4_check_dir_entry(inode, NULL, de, bh,
					 bh->b_data, bh->b_size, offset)) {
			offset = (offset | (sb->s_blocksize - 1)) + 1;
			continue;
		}
		if (le32_to_cpu(de->inode)) {
			brelse(bh);
			return false;
		}
		offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
	}
	brelse(bh);
	return true;
}


static __le32 ext4_dirblock_csum(struct inode *inode, void *dirent, int size)
{
	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
	struct ext4_inode_info *ei = EXT4_I(inode);
	__u32 csum;

	csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
	return cpu_to_le32(csum);
}


static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
{
	struct dx_countlimit *c;
	struct dx_tail *t;
	int count_offset, limit, count;

	if (!ext4_has_metadata_csum(inode->i_sb))
		return;

	c = get_dx_countlimit(inode, dirent, &count_offset);
	if (!c) {
		EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
		return;
	}
	limit = le16_to_cpu(c->limit);
	count = le16_to_cpu(c->count);
	if (count_offset + (limit * sizeof(struct dx_entry)) >
	    EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
		warn_no_space_for_csum(inode);
		return;
	}
	t = (struct dx_tail *)(((struct dx_entry *)c) + limit);

	t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
}


static int ext4_mknod(struct inode *dir, struct dentry *dentry,
		      umode_t mode, dev_t rdev)
{
	handle_t *handle;
	struct inode *inode;
	int err, credits, retries = 0;

	err = dquot_initialize(dir);
	if (err)
		return err;

	credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
		   EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
retry:
	inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0,
					    NULL, EXT4_HT_DIR, credits);
	handle = ext4_journal_current_handle();
	err = PTR_ERR(inode);
	if (!IS_ERR(inode)) {
		init_special_inode(inode, inode->i_mode, rdev);
		inode->i_op = &ext4_special_inode_operations;
		err = ext4_add_nondir(handle, dentry, &inode);
	}
	if (handle)
		ext4_journal_stop(handle);
	if (!IS_ERR_OR_NULL(inode))
		iput(inode);
	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
		goto retry;
	return err;
}


static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
			  struct inode *inode)
{
	struct inode *dir = d_inode(dentry->d_parent);
	struct buffer_head *bh = NULL;
	struct ext4_dir_entry_2 *de;
	struct super_block *sb;
#ifdef CONFIG_UNICODE
	struct ext4_sb_info *sbi;
#endif
	struct ext4_filename fname;
	int	retval;
	int	dx_fallback=0;
	unsigned blocksize;
	ext4_lblk_t block, blocks;
	int	csum_size = 0;

	if (ext4_has_metadata_csum(inode->i_sb))
		csum_size = sizeof(struct ext4_dir_entry_tail);

	sb = dir->i_sb;
	blocksize = sb->s_blocksize;
	if (!dentry->d_name.len)
		return -EINVAL;

#ifdef CONFIG_UNICODE
	sbi = EXT4_SB(sb);
	if (ext4_has_strict_mode(sbi) && IS_CASEFOLDED(dir) &&
	    sbi->s_encoding && utf8_validate(sbi->s_encoding, &dentry->d_name))
		return -EINVAL;
#endif

	retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
	if (retval)
		return retval;

	if (ext4_has_inline_data(dir)) {
		retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
		if (retval < 0)
			goto out;
		if (retval == 1) {
			retval = 0;
			goto out;
		}
	}

	if (is_dx(dir)) {
		retval = ext4_dx_add_entry(handle, &fname, dir, inode);
		if (!retval || (retval != ERR_BAD_DX_DIR))
			goto out;
		/* Can we just ignore htree data? */
		if (ext4_has_metadata_csum(sb)) {
			EXT4_ERROR_INODE(dir,
				"Directory has corrupted htree index.");
			retval = -EFSCORRUPTED;
			goto out;
		}
		ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
		dx_fallback++;
		retval = ext4_mark_inode_dirty(handle, dir);
		if (unlikely(retval))
			goto out;
	}
	blocks = dir->i_size >> sb->s_blocksize_bits;
	for (block = 0; block < blocks; block++) {
		bh = ext4_read_dirblock(dir, block, DIRENT);
		if (bh == NULL) {
			bh = ext4_bread(handle, dir, block,
					EXT4_GET_BLOCKS_CREATE);
			goto add_to_new_block;
		}
		if (IS_ERR(bh)) {
			retval = PTR_ERR(bh);
			bh = NULL;
			goto out;
		}
		retval = add_dirent_to_buf(handle, &fname, dir, inode,
					   NULL, bh);
		if (retval != -ENOSPC)
			goto out;

		if (blocks == 1 && !dx_fallback &&
		    ext4_has_feature_dir_index(sb)) {
			retval = make_indexed_dir(handle, &fname, dir,
						  inode, bh);
			bh = NULL; /* make_indexed_dir releases bh */
			goto out;
		}
		brelse(bh);
	}
	bh = ext4_append(handle, dir, &block);
add_to_new_block:
	if (IS_ERR(bh)) {
		retval = PTR_ERR(bh);
		bh = NULL;
		goto out;
	}
	de = (struct ext4_dir_entry_2 *) bh->b_data;
	de->inode = 0;
	de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);

	if (csum_size)
		ext4_initialize_dirent_tail(bh, blocksize);

	retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
out:
	ext4_fname_free_filename(&fname);
	brelse(bh);
	if (retval == 0)
		ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
	return retval;
}


struct dentry *ext4_get_parent(struct dentry *child)
{
	__u32 ino;
	static const struct qstr dotdot = QSTR_INIT("..", 2);
	struct ext4_dir_entry_2 * de;
	struct buffer_head *bh;

	bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL);
	if (IS_ERR(bh))
		return ERR_CAST(bh);
	if (!bh)
		return ERR_PTR(-ENOENT);
	ino = le32_to_cpu(de->inode);
	brelse(bh);

	if (!ext4_valid_inum(child->d_sb, ino)) {
		EXT4_ERROR_INODE(d_inode(child),
				 "bad parent inode number: %u", ino);
		return ERR_PTR(-EFSCORRUPTED);
	}

	return d_obtain_alias(ext4_iget(child->d_sb, ino, EXT4_IGET_NORMAL));
}


int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
			 __u32 start_minor_hash, __u32 *next_hash)
{
	struct dx_hash_info hinfo;
	struct ext4_dir_entry_2 *de;
	struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
	struct inode *dir;
	ext4_lblk_t block;
	int count = 0;
	int ret, err;
	__u32 hashval;
	struct fscrypt_str tmp_str;

	dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
		       start_hash, start_minor_hash));
	dir = file_inode(dir_file);
	if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
		hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
		if (hinfo.hash_version <= DX_HASH_TEA)
			hinfo.hash_version +=
				EXT4_SB(dir->i_sb)->s_hash_unsigned;
		hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
		if (ext4_has_inline_data(dir)) {
			int has_inline_data = 1;
			count = ext4_inlinedir_to_tree(dir_file, dir, 0,
						       &hinfo, start_hash,
						       start_minor_hash,
						       &has_inline_data);
			if (has_inline_data) {
				*next_hash = ~0;
				return count;
			}
		}
		count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
					       start_hash, start_minor_hash);
		*next_hash = ~0;
		return count;
	}
	hinfo.hash = start_hash;
	hinfo.minor_hash = 0;
	frame = dx_probe(NULL, dir, &hinfo, frames);
	if (IS_ERR(frame))
		return PTR_ERR(frame);

	/* Add '.' and '..' from the htree header */
	if (!start_hash && !start_minor_hash) {
		de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
		tmp_str.name = de->name;
		tmp_str.len = de->name_len;
		err = ext4_htree_store_dirent(dir_file, 0, 0,
					      de, &tmp_str);
		if (err != 0)
			goto errout;
		count++;
	}
	if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
		de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
		de = ext4_next_entry(de, dir->i_sb->s_blocksize);
		tmp_str.name = de->name;
		tmp_str.len = de->name_len;
		err = ext4_htree_store_dirent(dir_file, 2, 0,
					      de, &tmp_str);
		if (err != 0)
			goto errout;
		count++;
	}

	while (1) {
		if (fatal_signal_pending(current)) {
			err = -ERESTARTSYS;
			goto errout;
		}
		cond_resched();
		block = dx_get_block(frame->at);
		ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
					     start_hash, start_minor_hash);
		if (ret < 0) {
			err = ret;
			goto errout;
		}
		count += ret;
		hashval = ~0;
		ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
					    frame, frames, &hashval);
		*next_hash = hashval;
		if (ret < 0) {
			err = ret;
			goto errout;
		}
		/*
		 * Stop if:  (a) there are no more entries, or
		 * (b) we have inserted at least one entry and the
		 * next hash value is not a continuation
		 */
		if ((ret == 0) ||
		    (count && ((hashval & 1) == 0)))
			break;
	}
	dx_release(frames);
	dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
		       "next hash: %x\n", count, *next_hash));
	return count;
errout:
	dx_release(frames);
	return (err);
}


static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
			     struct inode *new_dir, struct dentry *new_dentry)
{
	handle_t *handle = NULL;
	struct ext4_renament old = {
		.dir = old_dir,
		.dentry = old_dentry,
		.inode = d_inode(old_dentry),
	};
	struct ext4_renament new = {
		.dir = new_dir,
		.dentry = new_dentry,
		.inode = d_inode(new_dentry),
	};
	u8 new_file_type;
	int retval;
	struct timespec64 ctime;

	if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
	     !projid_eq(EXT4_I(new_dir)->i_projid,
			EXT4_I(old_dentry->d_inode)->i_projid)) ||
	    (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
	     !projid_eq(EXT4_I(old_dir)->i_projid,
			EXT4_I(new_dentry->d_inode)->i_projid)))
		return -EXDEV;

	retval = dquot_initialize(old.dir);
	if (retval)
		return retval;
	retval = dquot_initialize(new.dir);
	if (retval)
		return retval;

	old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
				 &old.de, &old.inlined);
	if (IS_ERR(old.bh))
		return PTR_ERR(old.bh);
	/*
	 *  Check for inode number is _not_ due to possible IO errors.
	 *  We might rmdir the source, keep it as pwd of some process
	 *  and merrily kill the link to whatever was created under the
	 *  same name. Goodbye sticky bit ;-<
	 */
	retval = -ENOENT;
	if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
		goto end_rename;

	new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
				 &new.de, &new.inlined);
	if (IS_ERR(new.bh)) {
		retval = PTR_ERR(new.bh);
		new.bh = NULL;
		goto end_rename;
	}

	/* RENAME_EXCHANGE case: old *and* new must both exist */
	if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
		goto end_rename;

	handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
		(2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
		 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
	if (IS_ERR(handle)) {
		retval = PTR_ERR(handle);
		handle = NULL;
		goto end_rename;
	}

	if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
		ext4_handle_sync(handle);

	if (S_ISDIR(old.inode->i_mode)) {
		old.is_dir = true;
		retval = ext4_rename_dir_prepare(handle, &old);
		if (retval)
			goto end_rename;
	}
	if (S_ISDIR(new.inode->i_mode)) {
		new.is_dir = true;
		retval = ext4_rename_dir_prepare(handle, &new);
		if (retval)
			goto end_rename;
	}

	/*
	 * Other than the special case of overwriting a directory, parents'
	 * nlink only needs to be modified if this is a cross directory rename.
	 */
	if (old.dir != new.dir && old.is_dir != new.is_dir) {
		old.dir_nlink_delta = old.is_dir ? -1 : 1;
		new.dir_nlink_delta = -old.dir_nlink_delta;
		retval = -EMLINK;
		if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
		    (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
			goto end_rename;
	}

	new_file_type = new.de->file_type;
	retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
	if (retval)
		goto end_rename;

	retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
	if (retval)
		goto end_rename;

	/*
	 * Like most other Unix systems, set the ctime for inodes on a
	 * rename.
	 */
	ctime = current_time(old.inode);
	old.inode->i_ctime = ctime;
	new.inode->i_ctime = ctime;
	retval = ext4_mark_inode_dirty(handle, old.inode);
	if (unlikely(retval))
		goto end_rename;
	retval = ext4_mark_inode_dirty(handle, new.inode);
	if (unlikely(retval))
		goto end_rename;

	if (old.dir_bh) {
		retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
		if (retval)
			goto end_rename;
	}
	if (new.dir_bh) {
		retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
		if (retval)
			goto end_rename;
	}
	ext4_update_dir_count(handle, &old);
	ext4_update_dir_count(handle, &new);
	retval = 0;

end_rename:
	brelse(old.dir_bh);
	brelse(new.dir_bh);
	brelse(old.bh);
	brelse(new.bh);
	if (handle)
		ext4_journal_stop(handle);
	return retval;
}


static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
						   struct buffer_head *bh)
{
	struct ext4_dir_entry_tail *t;

#ifdef PARANOID
	struct ext4_dir_entry *d, *top;

	d = (struct ext4_dir_entry *)bh->b_data;
	top = (struct ext4_dir_entry *)(bh->b_data +
		(EXT4_BLOCK_SIZE(inode->i_sb) -
		 sizeof(struct ext4_dir_entry_tail)));
	while (d < top && d->rec_len)
		d = (struct ext4_dir_entry *)(((void *)d) +
		    le16_to_cpu(d->rec_len));

	if (d != top)
		return NULL;

	t = (struct ext4_dir_entry_tail *)d;
#else
	t = EXT4_DIRENT_TAIL(bh->b_data, EXT4_BLOCK_SIZE(inode->i_sb));
#endif

	if (t->det_reserved_zero1 ||
	    le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) ||
	    t->det_reserved_zero2 ||
	    t->det_reserved_ft != EXT4_FT_DIR_CSUM)
		return NULL;

	return t;
}


static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
		       struct inode *new_dir, struct dentry *new_dentry,
		       unsigned int flags)
{
	handle_t *handle = NULL;
	struct ext4_renament old = {
		.dir = old_dir,
		.dentry = old_dentry,
		.inode = d_inode(old_dentry),
	};
	struct ext4_renament new = {
		.dir = new_dir,
		.dentry = new_dentry,
		.inode = d_inode(new_dentry),
	};
	int force_reread;
	int retval;
	struct inode *whiteout = NULL;
	int credits;
	u8 old_file_type;

	if (new.inode && new.inode->i_nlink == 0) {
		EXT4_ERROR_INODE(new.inode,
				 "target of rename is already freed");
		return -EFSCORRUPTED;
	}

	if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) &&
	    (!projid_eq(EXT4_I(new_dir)->i_projid,
			EXT4_I(old_dentry->d_inode)->i_projid)))
		return -EXDEV;

	retval = dquot_initialize(old.dir);
	if (retval)
		return retval;
	retval = dquot_initialize(new.dir);
	if (retval)
		return retval;

	/* Initialize quotas before so that eventual writes go
	 * in separate transaction */
	if (new.inode) {
		retval = dquot_initialize(new.inode);
		if (retval)
			return retval;
	}

	old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
	if (IS_ERR(old.bh))
		return PTR_ERR(old.bh);
	/*
	 *  Check for inode number is _not_ due to possible IO errors.
	 *  We might rmdir the source, keep it as pwd of some process
	 *  and merrily kill the link to whatever was created under the
	 *  same name. Goodbye sticky bit ;-<
	 */
	retval = -ENOENT;
	if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
		goto end_rename;

	new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
				 &new.de, &new.inlined);
	if (IS_ERR(new.bh)) {
		retval = PTR_ERR(new.bh);
		new.bh = NULL;
		goto end_rename;
	}
	if (new.bh) {
		if (!new.inode) {
			brelse(new.bh);
			new.bh = NULL;
		}
	}
	if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
		ext4_alloc_da_blocks(old.inode);

	credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
		   EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
	if (!(flags & RENAME_WHITEOUT)) {
		handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
		if (IS_ERR(handle)) {
			retval = PTR_ERR(handle);
			handle = NULL;
			goto end_rename;
		}
	} else {
		whiteout = ext4_whiteout_for_rename(&old, credits, &handle);
		if (IS_ERR(whiteout)) {
			retval = PTR_ERR(whiteout);
			whiteout = NULL;
			goto end_rename;
		}
	}

	if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
		ext4_handle_sync(handle);

	if (S_ISDIR(old.inode->i_mode)) {
		if (new.inode) {
			retval = -ENOTEMPTY;
			if (!ext4_empty_dir(new.inode))
				goto end_rename;
		} else {
			retval = -EMLINK;
			if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
				goto end_rename;
		}
		retval = ext4_rename_dir_prepare(handle, &old);
		if (retval)
			goto end_rename;
	}
	/*
	 * If we're renaming a file within an inline_data dir and adding or
	 * setting the new dirent causes a conversion from inline_data to
	 * extents/blockmap, we need to force the dirent delete code to
	 * re-read the directory, or else we end up trying to delete a dirent
	 * from what is now the extent tree root (or a block map).
	 */
	force_reread = (new.dir->i_ino == old.dir->i_ino &&
			ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));

	old_file_type = old.de->file_type;
	if (whiteout) {
		/*
		 * Do this before adding a new entry, so the old entry is sure
		 * to be still pointing to the valid old entry.
		 */
		retval = ext4_setent(handle, &old, whiteout->i_ino,
				     EXT4_FT_CHRDEV);
		if (retval)
			goto end_rename;
		retval = ext4_mark_inode_dirty(handle, whiteout);
		if (unlikely(retval))
			goto end_rename;
	}
	if (!new.bh) {
		retval = ext4_add_entry(handle, new.dentry, old.inode);
		if (retval)
			goto end_rename;
	} else {
		retval = ext4_setent(handle, &new,
				     old.inode->i_ino, old_file_type);
		if (retval)
			goto end_rename;
	}
	if (force_reread)
		force_reread = !ext4_test_inode_flag(new.dir,
						     EXT4_INODE_INLINE_DATA);

	/*
	 * Like most other Unix systems, set the ctime for inodes on a
	 * rename.
	 */
	old.inode->i_ctime = current_time(old.inode);
	retval = ext4_mark_inode_dirty(handle, old.inode);
	if (unlikely(retval))
		goto end_rename;

	if (!whiteout) {
		/*
		 * ok, that's it
		 */
		ext4_rename_delete(handle, &old, force_reread);
	}

	if (new.inode) {
		ext4_dec_count(handle, new.inode);
		new.inode->i_ctime = current_time(new.inode);
	}
	old.dir->i_ctime = old.dir->i_mtime = current_time(old.dir);
	ext4_update_dx_flag(old.dir);
	if (old.dir_bh) {
		retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
		if (retval)
			goto end_rename;

		ext4_dec_count(handle, old.dir);
		if (new.inode) {
			/* checked ext4_empty_dir above, can't have another
			 * parent, ext4_dec_count() won't work for many-linked
			 * dirs */
			clear_nlink(new.inode);
		} else {
			ext4_inc_count(handle, new.dir);
			ext4_update_dx_flag(new.dir);
			retval = ext4_mark_inode_dirty(handle, new.dir);
			if (unlikely(retval))
				goto end_rename;
		}
	}
	retval = ext4_mark_inode_dirty(handle, old.dir);
	if (unlikely(retval))
		goto end_rename;
	if (new.inode) {
		retval = ext4_mark_inode_dirty(handle, new.inode);
		if (unlikely(retval))
			goto end_rename;
		if (!new.inode->i_nlink)
			ext4_orphan_add(handle, new.inode);
	}
	retval = 0;

end_rename:
	brelse(old.dir_bh);
	brelse(old.bh);
	brelse(new.bh);
	if (whiteout) {
		if (retval)
			drop_nlink(whiteout);
		unlock_new_inode(whiteout);
		iput(whiteout);
	}
	if (handle)
		ext4_journal_stop(handle);
	return retval;
}


void ext4_insert_dentry(struct inode *inode,
			struct ext4_dir_entry_2 *de,
			int buf_size,
			struct ext4_filename *fname)
{

	int nlen, rlen;

	nlen = EXT4_DIR_REC_LEN(de->name_len);
	rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
	if (de->inode) {
		struct ext4_dir_entry_2 *de1 =
			(struct ext4_dir_entry_2 *)((char *)de + nlen);
		de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
		de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
		de = de1;
	}
	de->file_type = EXT4_FT_UNKNOWN;
	de->inode = cpu_to_le32(inode->i_ino);
	ext4_set_de_type(inode->i_sb, de, inode->i_mode);
	de->name_len = fname_len(fname);
	memcpy(de->name, fname_name(fname), fname_len(fname));
}


static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
					struct inode *inode,
					int *retval,
					struct ext4_dir_entry_2 **parent_de,
					int *inlined)
{
	struct buffer_head *bh;

	if (!ext4_has_inline_data(inode)) {
		/* The first directory block must not be a hole, so
		 * treat it as DIRENT_HTREE
		 */
		bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);
		if (IS_ERR(bh)) {
			*retval = PTR_ERR(bh);
			return NULL;
		}
		*parent_de = ext4_next_entry(
					(struct ext4_dir_entry_2 *)bh->b_data,
					inode->i_sb->s_blocksize);
		return bh;
	}

	*inlined = 1;
	return ext4_get_first_inline_block(inode, parent_de, retval);
}


static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
{
	int retval;
	struct inode *inode;
	struct buffer_head *bh;
	struct ext4_dir_entry_2 *de;
	handle_t *handle = NULL;

	if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
		return -EIO;

	/* Initialize quotas before so that eventual writes go in
	 * separate transaction */
	retval = dquot_initialize(dir);
	if (retval)
		return retval;
	retval = dquot_initialize(d_inode(dentry));
	if (retval)
		return retval;

	retval = -ENOENT;
	bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
	if (IS_ERR(bh))
		return PTR_ERR(bh);
	if (!bh)
		goto end_rmdir;

	inode = d_inode(dentry);

	retval = -EFSCORRUPTED;
	if (le32_to_cpu(de->inode) != inode->i_ino)
		goto end_rmdir;

	retval = -ENOTEMPTY;
	if (!ext4_empty_dir(inode))
		goto end_rmdir;

	handle = ext4_journal_start(dir, EXT4_HT_DIR,
				    EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
	if (IS_ERR(handle)) {
		retval = PTR_ERR(handle);
		handle = NULL;
		goto end_rmdir;
	}

	if (IS_DIRSYNC(dir))
		ext4_handle_sync(handle);

	retval = ext4_delete_entry(handle, dir, de, bh);
	if (retval)
		goto end_rmdir;
	if (!EXT4_DIR_LINK_EMPTY(inode))
		ext4_warning_inode(inode,
			     "empty directory '%.*s' has too many links (%u)",
			     dentry->d_name.len, dentry->d_name.name,
			     inode->i_nlink);
	inode_inc_iversion(inode);
	clear_nlink(inode);
	/* There's no need to set i_disksize: the fact that i_nlink is
	 * zero will ensure that the right thing happens during any
	 * recovery. */
	inode->i_size = 0;
	ext4_orphan_add(handle, inode);
	inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode);
	retval = ext4_mark_inode_dirty(handle, inode);
	if (retval)
		goto end_rmdir;
	ext4_dec_count(handle, dir);
	ext4_update_dx_flag(dir);
	retval = ext4_mark_inode_dirty(handle, dir);

#ifdef CONFIG_UNICODE
	/* VFS negative dentries are incompatible with Encoding and
	 * Case-insensitiveness. Eventually we'll want avoid
	 * invalidating the dentries here, alongside with returning the
	 * negative dentries at ext4_lookup(), when it is better
	 * supported by the VFS for the CI case.
	 */
	if (IS_CASEFOLDED(dir))
		d_invalidate(dentry);
#endif

end_rmdir:
	brelse(bh);
	if (handle)
		ext4_journal_stop(handle);
	return retval;
}


static void dx_show_index(char * label, struct dx_entry *entries)
{
	int i, n = dx_get_count (entries);
	printk(KERN_DEBUG "%s index", label);
	for (i = 0; i < n; i++) {
		printk(KERN_CONT " %x->%lu",
		       i ? dx_get_hash(entries + i) : 0,
		       (unsigned long)dx_get_block(entries + i));
	}
	printk(KERN_CONT "\n");
}


int ext4_orphan_add(handle_t *handle, struct inode *inode)
{
	struct super_block *sb = inode->i_sb;
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_iloc iloc;
	int err = 0, rc;
	bool dirty = false;

	if (!sbi->s_journal || is_bad_inode(inode))
		return 0;

	WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) &&
		     !inode_is_locked(inode));
	/*
	 * Exit early if inode already is on orphan list. This is a big speedup
	 * since we don't have to contend on the global s_orphan_lock.
	 */
	if (!list_empty(&EXT4_I(inode)->i_orphan))
		return 0;

	/*
	 * Orphan handling is only valid for files with data blocks
	 * being truncated, or files being unlinked. Note that we either
	 * hold i_mutex, or the inode can not be referenced from outside,
	 * so i_nlink should not be bumped due to race
	 */
	J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
		  S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);

	BUFFER_TRACE(sbi->s_sbh, "get_write_access");
	err = ext4_journal_get_write_access(handle, sbi->s_sbh);
	if (err)
		goto out;

	err = ext4_reserve_inode_write(handle, inode, &iloc);
	if (err)
		goto out;

	mutex_lock(&sbi->s_orphan_lock);
	/*
	 * Due to previous errors inode may be already a part of on-disk
	 * orphan list. If so skip on-disk list modification.
	 */
	if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) >
	    (le32_to_cpu(sbi->s_es->s_inodes_count))) {
		/* Insert this inode at the head of the on-disk orphan list */
		NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan);
		sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
		dirty = true;
	}
	list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan);
	mutex_unlock(&sbi->s_orphan_lock);

	if (dirty) {
		err = ext4_handle_dirty_super(handle, sb);
		rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
		if (!err)
			err = rc;
		if (err) {
			/*
			 * We have to remove inode from in-memory list if
			 * addition to on disk orphan list failed. Stray orphan
			 * list entries can cause panics at unmount time.
			 */
			mutex_lock(&sbi->s_orphan_lock);
			list_del_init(&EXT4_I(inode)->i_orphan);
			mutex_unlock(&sbi->s_orphan_lock);
		}
	} else
		brelse(iloc.bh);

	jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
	jbd_debug(4, "orphan inode %lu will point to %d\n",
			inode->i_ino, NEXT_ORPHAN(inode));
out:
	ext4_std_error(sb, err);
	return err;
}


void ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
				  struct fscrypt_str *cf_name)
{
	int len;

	if (!IS_CASEFOLDED(dir) || !EXT4_SB(dir->i_sb)->s_encoding) {
		cf_name->name = NULL;
		return;
	}

	cf_name->name = kmalloc(EXT4_NAME_LEN, GFP_NOFS);
	if (!cf_name->name)
		return;

	len = utf8_casefold(EXT4_SB(dir->i_sb)->s_encoding,
			    iname, cf_name->name,
			    EXT4_NAME_LEN);
	if (len <= 0) {
		kfree(cf_name->name);
		cf_name->name = NULL;
		return;
	}
	cf_name->len = (unsigned) len;

}


static inline int search_dirblock(struct buffer_head *bh,
				  struct inode *dir,
				  struct ext4_filename *fname,
				  unsigned int offset,
				  struct ext4_dir_entry_2 **res_dir)
{
	return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
			       fname, offset, res_dir);
}


static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent,
					      int credits, handle_t **h)
{
	struct inode *wh;
	handle_t *handle;
	int retries = 0;

	/*
	 * for inode block, sb block, group summaries,
	 * and inode bitmap
	 */
	credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
		    EXT4_XATTR_TRANS_BLOCKS + 4);
retry:
	wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE,
					 &ent->dentry->d_name, 0, NULL,
					 EXT4_HT_DIR, credits);

	handle = ext4_journal_current_handle();
	if (IS_ERR(wh)) {
		if (handle)
			ext4_journal_stop(handle);
		if (PTR_ERR(wh) == -ENOSPC &&
		    ext4_should_retry_alloc(ent->dir->i_sb, &retries))
			goto retry;
	} else {
		*h = handle;
		init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
		wh->i_op = &ext4_special_inode_operations;
	}
	return wh;
}


static void dx_release(struct dx_frame *frames)
{
	struct dx_root_info *info;
	int i;
	unsigned int indirect_levels;

	if (frames[0].bh == NULL)
		return;

	info = &((struct dx_root *)frames[0].bh->b_data)->info;
	/* save local copy, "info" may be freed after brelse() */
	indirect_levels = info->indirect_levels;
	for (i = 0; i <= indirect_levels; i++) {
		if (frames[i].bh == NULL)
			break;
		brelse(frames[i].bh);
		frames[i].bh = NULL;
	}
}


static int ext4_dx_csum_verify(struct inode *inode,
			       struct ext4_dir_entry *dirent)
{
	struct dx_countlimit *c;
	struct dx_tail *t;
	int count_offset, limit, count;

	if (!ext4_has_metadata_csum(inode->i_sb))
		return 1;

	c = get_dx_countlimit(inode, dirent, &count_offset);
	if (!c) {
		EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
		return 0;
	}
	limit = le16_to_cpu(c->limit);
	count = le16_to_cpu(c->count);
	if (count_offset + (limit * sizeof(struct dx_entry)) >
	    EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
		warn_no_space_for_csum(inode);
		return 0;
	}
	t = (struct dx_tail *)(((struct dx_entry *)c) + limit);

	if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
					    count, t))
		return 0;
	return 1;
}


ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
{
	return (struct ext4_dir_entry_2 *)((char *)p +
		ext4_rec_len_from_disk(p->rec_len, blocksize));
}


static int ext4_delete_entry(handle_t *handle,
			     struct inode *dir,
			     struct ext4_dir_entry_2 *de_del,
			     struct buffer_head *bh)
{
	int err, csum_size = 0;

	if (ext4_has_inline_data(dir)) {
		int has_inline_data = 1;
		err = ext4_delete_inline_entry(handle, dir, de_del, bh,
					       &has_inline_data);
		if (has_inline_data)
			return err;
	}

	if (ext4_has_metadata_csum(dir->i_sb))
		csum_size = sizeof(struct ext4_dir_entry_tail);

	BUFFER_TRACE(bh, "get_write_access");
	err = ext4_journal_get_write_access(handle, bh);
	if (unlikely(err))
		goto out;

	err = ext4_generic_delete_entry(handle, dir, de_del,
					bh, bh->b_data,
					dir->i_sb->s_blocksize, csum_size);
	if (err)
		goto out;

	BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
	err = ext4_handle_dirty_dirblock(handle, dir, bh);
	if (unlikely(err))
		goto out;

	return 0;
out:
	if (err != -ENOENT)
		ext4_std_error(dir->i_sb, err);
	return err;
}


static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
{
	entry->hash = cpu_to_le32(value);
}


static void ext4_dec_count(handle_t *handle, struct inode *inode)
{
	if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
		drop_nlink(inode);
}


static int ext4_add_nondir(handle_t *handle,
		struct dentry *dentry, struct inode **inodep)
{
	struct inode *dir = d_inode(dentry->d_parent);
	struct inode *inode = *inodep;
	int err = ext4_add_entry(handle, dentry, inode);
	if (!err) {
		err = ext4_mark_inode_dirty(handle, inode);
		if (IS_DIRSYNC(dir))
			ext4_handle_sync(handle);
		d_instantiate_new(dentry, inode);
		*inodep = NULL;
		return err;
	}
	drop_nlink(inode);
	ext4_orphan_add(handle, inode);
	unlock_new_inode(inode);
	return err;
}


static int dx_make_map(struct inode *dir, struct ext4_dir_entry_2 *de,
		       unsigned blocksize, struct dx_hash_info *hinfo,
		       struct dx_map_entry *map_tail)
{
	int count = 0;
	char *base = (char *) de;
	struct dx_hash_info h = *hinfo;

	while ((char *) de < base + blocksize) {
		if (de->name_len && de->inode) {
			ext4fs_dirhash(dir, de->name, de->name_len, &h);
			map_tail--;
			map_tail->hash = h.hash;
			map_tail->offs = ((char *) de - base)>>2;
			map_tail->size = le16_to_cpu(de->rec_len);
			count++;
			cond_resched();
		}
		/* XXX: do we need to check rec_len == 0 case? -Chris */
		de = ext4_next_entry(de, blocksize);
	}
	return count;
}


static struct buffer_head *ext4_append(handle_t *handle,
					struct inode *inode,
					ext4_lblk_t *block)
{
	struct buffer_head *bh;
	int err;

	if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
		     ((inode->i_size >> 10) >=
		      EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
		return ERR_PTR(-ENOSPC);

	*block = inode->i_size >> inode->i_sb->s_blocksize_bits;

	bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
	if (IS_ERR(bh))
		return bh;
	inode->i_size += inode->i_sb->s_blocksize;
	EXT4_I(inode)->i_disksize = inode->i_size;
	BUFFER_TRACE(bh, "get_write_access");
	err = ext4_journal_get_write_access(handle, bh);
	if (err) {
		brelse(bh);
		ext4_std_error(inode->i_sb, err);
		return ERR_PTR(err);
	}
	return bh;
}


static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
			     struct inode *dir,
			     struct inode *inode, struct ext4_dir_entry_2 *de,
			     struct buffer_head *bh)
{
	unsigned int	blocksize = dir->i_sb->s_blocksize;
	int		csum_size = 0;
	int		err, err2;

	if (ext4_has_metadata_csum(inode->i_sb))
		csum_size = sizeof(struct ext4_dir_entry_tail);

	if (!de) {
		err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
					blocksize - csum_size, fname, &de);
		if (err)
			return err;
	}
	BUFFER_TRACE(bh, "get_write_access");
	err = ext4_journal_get_write_access(handle, bh);
	if (err) {
		ext4_std_error(dir->i_sb, err);
		return err;
	}

	/* By now the buffer is marked for journaling */
	ext4_insert_dentry(inode, de, blocksize, fname);

	/*
	 * XXX shouldn't update any times until successful
	 * completion of syscall, but too many callers depend
	 * on this.
	 *
	 * XXX similarly, too many callers depend on
	 * ext4_new_inode() setting the times, but error
	 * recovery deletes the inode, so the worst that can
	 * happen is that the times are slightly out of date
	 * and/or different from the directory change time.
	 */
	dir->i_mtime = dir->i_ctime = current_time(dir);
	ext4_update_dx_flag(dir);
	inode_inc_iversion(dir);
	err2 = ext4_mark_inode_dirty(handle, dir);
	BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
	err = ext4_handle_dirty_dirblock(handle, dir, bh);
	if (err)
		ext4_std_error(dir->i_sb, err);
	return err ? err : err2;
}


static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
			struct inode *new_dir, struct dentry *new_dentry,
			unsigned int flags)
{
	int err;

	if (unlikely(ext4_forced_shutdown(EXT4_SB(old_dir->i_sb))))
		return -EIO;

	if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
		return -EINVAL;

	err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
				     flags);
	if (err)
		return err;

	if (flags & RENAME_EXCHANGE) {
		return ext4_cross_rename(old_dir, old_dentry,
					 new_dir, new_dentry);
	}

	return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
}


static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
			    struct inode *dir,
			    struct inode *inode, struct buffer_head *bh)
{
	struct buffer_head *bh2;
	struct dx_root	*root;
	struct dx_frame	frames[EXT4_HTREE_LEVEL], *frame;
	struct dx_entry *entries;
	struct ext4_dir_entry_2	*de, *de2;
	char		*data2, *top;
	unsigned	len;
	int		retval;
	unsigned	blocksize;
	ext4_lblk_t  block;
	struct fake_dirent *fde;
	int csum_size = 0;

	if (ext4_has_metadata_csum(inode->i_sb))
		csum_size = sizeof(struct ext4_dir_entry_tail);

	blocksize =  dir->i_sb->s_blocksize;
	dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
	BUFFER_TRACE(bh, "get_write_access");
	retval = ext4_journal_get_write_access(handle, bh);
	if (retval) {
		ext4_std_error(dir->i_sb, retval);
		brelse(bh);
		return retval;
	}
	root = (struct dx_root *) bh->b_data;

	/* The 0th block becomes the root, move the dirents out */
	fde = &root->dotdot;
	de = (struct ext4_dir_entry_2 *)((char *)fde +
		ext4_rec_len_from_disk(fde->rec_len, blocksize));
	if ((char *) de >= (((char *) root) + blocksize)) {
		EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
		brelse(bh);
		return -EFSCORRUPTED;
	}
	len = ((char *) root) + (blocksize - csum_size) - (char *) de;

	/* Allocate new block for the 0th block's dirents */
	bh2 = ext4_append(handle, dir, &block);
	if (IS_ERR(bh2)) {
		brelse(bh);
		return PTR_ERR(bh2);
	}
	ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
	data2 = bh2->b_data;

	memcpy(data2, de, len);
	de = (struct ext4_dir_entry_2 *) data2;
	top = data2 + len;
	while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
		de = de2;
	de->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
					   (char *) de, blocksize);

	if (csum_size)
		ext4_initialize_dirent_tail(bh2, blocksize);

	/* Initialize the root; the dot dirents already exist */
	de = (struct ext4_dir_entry_2 *) (&root->dotdot);
	de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
					   blocksize);
	memset (&root->info, 0, sizeof(root->info));
	root->info.info_length = sizeof(root->info);
	root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
	entries = root->entries;
	dx_set_block(entries, 1);
	dx_set_count(entries, 1);
	dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));

	/* Initialize as for dx_probe */
	fname->hinfo.hash_version = root->info.hash_version;
	if (fname->hinfo.hash_version <= DX_HASH_TEA)
		fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
	fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
	ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), &fname->hinfo);

	memset(frames, 0, sizeof(frames));
	frame = frames;
	frame->entries = entries;
	frame->at = entries;
	frame->bh = bh;

	retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
	if (retval)
		goto out_frames;
	retval = ext4_handle_dirty_dirblock(handle, dir, bh2);
	if (retval)
		goto out_frames;

	de = do_split(handle,dir, &bh2, frame, &fname->hinfo);
	if (IS_ERR(de)) {
		retval = PTR_ERR(de);
		goto out_frames;
	}

	retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2);
out_frames:
	/*
	 * Even if the block split failed, we have to properly write
	 * out all the changes we did so far. Otherwise we can end up
	 * with corrupted filesystem.
	 */
	if (retval)
		ext4_mark_inode_dirty(handle, dir);
	dx_release(frames);
	brelse(bh2);
	return retval;
}


static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
	struct inode *inode;
	struct ext4_dir_entry_2 *de;
	struct buffer_head *bh;

	if (dentry->d_name.len > EXT4_NAME_LEN)
		return ERR_PTR(-ENAMETOOLONG);

	bh = ext4_lookup_entry(dir, dentry, &de);
	if (IS_ERR(bh))
		return ERR_CAST(bh);
	inode = NULL;
	if (bh) {
		__u32 ino = le32_to_cpu(de->inode);
		brelse(bh);
		if (!ext4_valid_inum(dir->i_sb, ino)) {
			EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
			return ERR_PTR(-EFSCORRUPTED);
		}
		if (unlikely(ino == dir->i_ino)) {
			EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
					 dentry);
			return ERR_PTR(-EFSCORRUPTED);
		}
		inode = ext4_iget(dir->i_sb, ino, EXT4_IGET_NORMAL);
		if (inode == ERR_PTR(-ESTALE)) {
			EXT4_ERROR_INODE(dir,
					 "deleted inode referenced: %u",
					 ino);
			return ERR_PTR(-EFSCORRUPTED);
		}
		if (!IS_ERR(inode) && IS_ENCRYPTED(dir) &&
		    (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
		    !fscrypt_has_permitted_context(dir, inode)) {
			ext4_warning(inode->i_sb,
				     "Inconsistent encryption contexts: %lu/%lu",
				     dir->i_ino, inode->i_ino);
			iput(inode);
			return ERR_PTR(-EPERM);
		}
	}

#ifdef CONFIG_UNICODE
	if (!inode && IS_CASEFOLDED(dir)) {
		/* Eventually we want to call d_add_ci(dentry, NULL)
		 * for negative dentries in the encoding case as
		 * well.  For now, prevent the negative dentry
		 * from being cached.
		 */
		return NULL;
	}
#endif
	return d_splice_alias(inode, dentry);
}


int ext4_ci_compare(const struct inode *parent, const struct qstr *name,
		    const struct qstr *entry, bool quick)
{
	const struct ext4_sb_info *sbi = EXT4_SB(parent->i_sb);
	const struct unicode_map *um = sbi->s_encoding;
	int ret;

	if (quick)
		ret = utf8_strncasecmp_folded(um, name, entry);
	else
		ret = utf8_strncasecmp(um, name, entry);

	if (ret < 0) {
		/* Handle invalid character sequence as either an error
		 * or as an opaque byte sequence.
		 */
		if (ext4_has_strict_mode(sbi))
			return -EINVAL;

		if (name->len != entry->len)
			return 1;

		return !!memcmp(name->name, entry->name, name->len);
	}

	return ret;
}


static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
	handle_t *handle;
	struct inode *inode;
	int err, err2 = 0, credits, retries = 0;

	if (EXT4_DIR_LINK_MAX(dir))
		return -EMLINK;

	err = dquot_initialize(dir);
	if (err)
		return err;

	credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
		   EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
retry:
	inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode,
					    &dentry->d_name,
					    0, NULL, EXT4_HT_DIR, credits);
	handle = ext4_journal_current_handle();
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out_stop;

	inode->i_op = &ext4_dir_inode_operations;
	inode->i_fop = &ext4_dir_operations;
	err = ext4_init_new_dir(handle, dir, inode);
	if (err)
		goto out_clear_inode;
	err = ext4_mark_inode_dirty(handle, inode);
	if (!err)
		err = ext4_add_entry(handle, dentry, inode);
	if (err) {
out_clear_inode:
		clear_nlink(inode);
		ext4_orphan_add(handle, inode);
		unlock_new_inode(inode);
		err2 = ext4_mark_inode_dirty(handle, inode);
		if (unlikely(err2))
			err = err2;
		ext4_journal_stop(handle);
		iput(inode);
		goto out_retry;
	}
	ext4_inc_count(handle, dir);
	ext4_update_dx_flag(dir);
	err = ext4_mark_inode_dirty(handle, dir);
	if (err)
		goto out_clear_inode;
	d_instantiate_new(dentry, inode);
	if (IS_DIRSYNC(dir))
		ext4_handle_sync(handle);

out_stop:
	if (handle)
		ext4_journal_stop(handle);
out_retry:
	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
		goto retry;
	return err;
}