iov_iter_truncate()

Now It Can Be Done(tm) - we don't need to do iov_shorten() in generic_file_direct_write() anymore, now that all ->direct_IO() instances are converted to proper iov_iter methods and honour iter->count and iter->iov_offset properly. Get rid of count/ocount arguments of generic_file_direct_write(), while we are at it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

iov_iter_truncate()
Now It Can Be Done(tm) - we don't need to do iov_shorten() in generic_file_direct_write() anymore, now that all ->direct_IO() instances are converted to proper iov_iter methods and honour iter->count and iter->iov_offset properly. Get rid of count/ocount arguments of generic_file_direct_write(), while we are at it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro
1 parent 28060d5d9b
Showing 7 changed files with 40 additions and 42 deletions Side-by-side Diff
fs/btrfs/file.c
fs/fuse/file.c
fs/ocfs2/file.c
fs/xfs/xfs_file.c
include/linux/fs.h
include/linux/uio.h
mm/filemap.c
@@ -1659,8 +1659,7 @@
  
 static ssize_t __btrfs_direct_write(struct kiocb *iocb,
 				    struct iov_iter *from,
-				    loff_t pos,
-				    size_t count, size_t ocount)
+				    loff_t pos)
 {
 	struct file *file = iocb->ki_filp;
 	ssize_t written;
  
@@ -1668,9 +1667,9 @@
 	loff_t endbyte;
 	int err;
  
-	written = generic_file_direct_write(iocb, from, pos, count, ocount);
+	written = generic_file_direct_write(iocb, from, pos);
  
-	if (written < 0 || written == count)
+	if (written < 0 || !iov_iter_count(from))
 		return written;
  
 	pos += written;
  
@@ -1720,13 +1719,14 @@
 	u64 end_pos;
 	ssize_t num_written = 0;
 	ssize_t err = 0;
-	size_t count, ocount;
+	size_t count;
 	bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host);
 	struct iov_iter i;
  
 	mutex_lock(&inode->i_mutex);
  
-	count = ocount = iov_length(iov, nr_segs);
+	count = iov_length(iov, nr_segs);
+	iov_iter_init(&i, WRITE, iov, nr_segs, count);
  
 	current->backing_dev_info = inode->i_mapping->backing_dev_info;
 	err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
@@ -1740,7 +1740,7 @@
 		goto out;
 	}
  
-	iov_iter_init(&i, WRITE, iov, nr_segs, count);
+	iov_iter_truncate(&i, count);
  
 	err = file_remove_suid(file);
 	if (err) {
@@ -1783,8 +1783,7 @@
 		atomic_inc(&BTRFS_I(inode)->sync_writers);
  
 	if (unlikely(file->f_flags & O_DIRECT)) {
-		num_written = __btrfs_direct_write(iocb, &i,
-						   pos, count, ocount);
+		num_written = __btrfs_direct_write(iocb, &i, pos);
 	} else {
 		num_written = __btrfs_buffered_write(file, &i, pos);
 		if (num_written > 0)
@@ -1188,8 +1188,7 @@
 {
 	struct file *file = iocb->ki_filp;
 	struct address_space *mapping = file->f_mapping;
-	size_t count = 0;
-	size_t ocount = 0;
+	size_t count;
 	ssize_t written = 0;
 	ssize_t written_buffered = 0;
 	struct inode *inode = mapping->host;
@@ -1208,7 +1207,8 @@
  
 	WARN_ON(iocb->ki_pos != pos);
  
-	count = ocount = iov_length(iov, nr_segs);
+	count = iov_length(iov, nr_segs);
+	iov_iter_init(&i, WRITE, iov, nr_segs, count);
 	mutex_lock(&inode->i_mutex);
  
 	/* We can write back this queue in page reclaim */
  
@@ -1217,11 +1217,11 @@
 	err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
 	if (err)
 		goto out;
-	iov_iter_init(&i, WRITE, iov, nr_segs, count);
  
 	if (count == 0)
 		goto out;
  
+	iov_iter_truncate(&i, count);
 	err = file_remove_suid(file);
 	if (err)
 		goto out;
@@ -1231,8 +1231,8 @@
 		goto out;
  
 	if (file->f_flags & O_DIRECT) {
-		written = generic_file_direct_write(iocb, &i, pos, count, ocount);
-		if (written < 0 || written == count)
+		written = generic_file_direct_write(iocb, &i, pos);
+		if (written < 0 || !iov_iter_count(&i))
 			goto out;
  
 		pos += written;
@@ -1469,8 +1469,7 @@
  
 	res = generic_write_checks(file, ppos, &count, 0);
 	if (!res) {
-		if (iter->count > count)
-			iter->count = count;
+		iov_iter_truncate(iter, count);
 		res = fuse_direct_io(io, iter, ppos, FUSE_DIO_WRITE);
 	}
  
@@ -2896,8 +2895,7 @@
 		if (offset >= i_size)
 			return 0;
 		count = min_t(loff_t, count, fuse_round_up(i_size - offset));
-		if (iter->count > count)
-			iter->count = count;
+		iov_iter_truncate(iter, count);
 	}
  
 	io = kmalloc(sizeof(struct fuse_io_priv), GFP_KERNEL);
@@ -2241,7 +2241,6 @@
 	int ret, direct_io, appending, rw_level, have_alloc_sem  = 0;
 	int can_do_direct, has_refcount = 0;
 	ssize_t written = 0;
-	size_t ocount;		/* original count */
 	size_t count;		/* after file limit checks */
 	loff_t old_size, *ppos = &iocb->ki_pos;
 	u32 old_clusters;
@@ -2253,6 +2252,9 @@
 	int unaligned_dio = 0;
 	struct iov_iter from;
  
+	count = iov_length(iov, nr_segs);
+	iov_iter_init(&from, WRITE, iov, nr_segs, count);
+
 	trace_ocfs2_file_aio_write(inode, file, file->f_path.dentry,
 		(unsigned long long)OCFS2_I(inode)->ip_blkno,
 		file->f_path.dentry->d_name.len,
  
  
@@ -2355,16 +2357,14 @@
 	/* communicate with ocfs2_dio_end_io */
 	ocfs2_iocb_set_rw_locked(iocb, rw_level);
  
-	count = ocount = iov_length(iov, nr_segs);
 	ret = generic_write_checks(file, ppos, &count,
 				   S_ISBLK(inode->i_mode));
 	if (ret)
 		goto out_dio;
  
-	iov_iter_init(&from, WRITE, iov, nr_segs, count);
+	iov_iter_truncate(&from, count);
 	if (direct_io) {
-		written = generic_file_direct_write(iocb, &from, *ppos,
-						    count, ocount);
+		written = generic_file_direct_write(iocb, &from, *ppos);
 		if (written < 0) {
 			ret = written;
 			goto out_dio;
@@ -626,7 +626,7 @@
 	const struct iovec	*iovp,
 	unsigned long		nr_segs,
 	loff_t			pos,
-	size_t			ocount)
+	size_t			count)
 {
 	struct file		*file = iocb->ki_filp;
 	struct address_space	*mapping = file->f_mapping;
@@ -634,7 +634,6 @@
 	struct xfs_inode	*ip = XFS_I(inode);
 	struct xfs_mount	*mp = ip->i_mount;
 	ssize_t			ret = 0;
-	size_t			count = ocount;
 	int			unaligned_io = 0;
 	int			iolock;
 	struct xfs_buftarg	*target = XFS_IS_REALTIME_INODE(ip) ?
@@ -645,6 +644,8 @@
 	if ((pos | count) & target->bt_logical_sectormask)
 		return -XFS_ERROR(EINVAL);
  
+	iov_iter_init(&from, WRITE, iovp, nr_segs, count);
+
 	/* "unaligned" here means not aligned to a filesystem block */
 	if ((pos & mp->m_blockmask) || ((pos + count) & mp->m_blockmask))
 		unaligned_io = 1;
@@ -676,6 +677,7 @@
 	ret = xfs_file_aio_write_checks(file, &pos, &count, &iolock);
 	if (ret)
 		goto out;
+	iov_iter_truncate(&from, count);
  
 	if (mapping->nrpages) {
 		ret = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
@@ -697,8 +699,7 @@
 	}
  
 	trace_xfs_file_direct_write(ip, count, iocb->ki_pos, 0);
-	iov_iter_init(&from, WRITE, iovp, nr_segs, count);
-	ret = generic_file_direct_write(iocb, &from, pos, count, ocount);
+	ret = generic_file_direct_write(iocb, &from, pos);
  
 out:
 	xfs_rw_iunlock(ip, iolock);
@@ -2407,8 +2407,7 @@
 extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *);
 extern ssize_t __generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long);
 extern ssize_t generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long, loff_t);
-extern ssize_t generic_file_direct_write(struct kiocb *, struct iov_iter *,
-		loff_t, size_t, size_t);
+extern ssize_t generic_file_direct_write(struct kiocb *, struct iov_iter *, loff_t);
 extern ssize_t generic_perform_write(struct file *, struct iov_iter *, loff_t);
 extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos);
 extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos);
@@ -82,6 +82,12 @@
 	return i->count;
 }
  
+static inline void iov_iter_truncate(struct iov_iter *i, size_t count)
+{
+	if (i->count > count)
+		i->count = count;
+}
+
 int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len);
 int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len);
  
@@ -2345,8 +2345,7 @@
 EXPORT_SYMBOL(pagecache_write_end);
  
 ssize_t
-generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from,
-		loff_t pos, size_t count, size_t ocount)
+generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from, loff_t pos)
 {
 	struct file	*file = iocb->ki_filp;
 	struct address_space *mapping = file->f_mapping;
@@ -2356,10 +2355,7 @@
 	pgoff_t		end;
 	struct iov_iter data;
  
-	if (count != ocount)
-		from->nr_segs = iov_shorten((struct iovec *)from->iov, from->nr_segs, count);
-
-	write_len = iov_length(from->iov, from->nr_segs);
+	write_len = iov_iter_count(from);
 	end = (pos + write_len - 1) >> PAGE_CACHE_SHIFT;
  
 	written = filemap_write_and_wait_range(mapping, pos, pos + write_len - 1);
@@ -2568,7 +2564,6 @@
 {
 	struct file *file = iocb->ki_filp;
 	struct address_space * mapping = file->f_mapping;
-	size_t ocount;		/* original count */
 	size_t count;		/* after file limit checks */
 	struct inode 	*inode = mapping->host;
 	loff_t		pos = iocb->ki_pos;
@@ -2577,7 +2572,8 @@
 	ssize_t		status;
 	struct iov_iter from;
  
-	count = ocount = iov_length(iov, nr_segs);
+	count = iov_length(iov, nr_segs);
+	iov_iter_init(&from, WRITE, iov, nr_segs, count);
  
 	/* We can write back this queue in page reclaim */
 	current->backing_dev_info = mapping->backing_dev_info;
@@ -2588,6 +2584,8 @@
 	if (count == 0)
 		goto out;
  
+	iov_iter_truncate(&from, count);
+
 	err = file_remove_suid(file);
 	if (err)
 		goto out;
  
@@ -2596,14 +2594,11 @@
 	if (err)
 		goto out;
  
-	iov_iter_init(&from, WRITE, iov, nr_segs, count);
-
 	/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
 	if (unlikely(file->f_flags & O_DIRECT)) {
 		loff_t endbyte;
  
-		written = generic_file_direct_write(iocb, &from, pos,
-							count, ocount);
+		written = generic_file_direct_write(iocb, &from, pos);
 		if (written < 0 || written == count)
 			goto out;
...	...	@@ -1659,8 +1659,7 @@
1659	1659
1660	1660	static ssize_t __btrfs_direct_write(struct kiocb *iocb,
1661	1661	struct iov_iter *from,
1662		- loff_t pos,
1663		- size_t count, size_t ocount)
	1662	+ loff_t pos)
1664	1663	{
1665	1664	struct file *file = iocb->ki_filp;
1666	1665	ssize_t written;
1667	1666
...	...	@@ -1668,9 +1667,9 @@
1668	1667	loff_t endbyte;
1669	1668	int err;
1670	1669
1671		- written = generic_file_direct_write(iocb, from, pos, count, ocount);
	1670	+ written = generic_file_direct_write(iocb, from, pos);
1672	1671
1673		- if (written < 0 \|\| written == count)
	1672	+ if (written < 0 \|\| !iov_iter_count(from))
1674	1673	return written;
1675	1674
1676	1675	pos += written;
1677	1676
...	...	@@ -1720,13 +1719,14 @@
1720	1719	u64 end_pos;
1721	1720	ssize_t num_written = 0;
1722	1721	ssize_t err = 0;
1723		- size_t count, ocount;
	1722	+ size_t count;
1724	1723	bool sync = (file->f_flags & O_DSYNC) \|\| IS_SYNC(file->f_mapping->host);
1725	1724	struct iov_iter i;
1726	1725
1727	1726	mutex_lock(&inode->i_mutex);
1728	1727
1729		- count = ocount = iov_length(iov, nr_segs);
	1728	+ count = iov_length(iov, nr_segs);
	1729	+ iov_iter_init(&i, WRITE, iov, nr_segs, count);
1730	1730
1731	1731	current->backing_dev_info = inode->i_mapping->backing_dev_info;
1732	1732	err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
...	...	@@ -1740,7 +1740,7 @@
1740	1740	goto out;
1741	1741	}
1742	1742
1743		- iov_iter_init(&i, WRITE, iov, nr_segs, count);
	1743	+ iov_iter_truncate(&i, count);
1744	1744
1745	1745	err = file_remove_suid(file);
1746	1746	if (err) {
...	...	@@ -1783,8 +1783,7 @@
1783	1783	atomic_inc(&BTRFS_I(inode)->sync_writers);
1784	1784
1785	1785	if (unlikely(file->f_flags & O_DIRECT)) {
1786		- num_written = __btrfs_direct_write(iocb, &i,
1787		- pos, count, ocount);
	1786	+ num_written = __btrfs_direct_write(iocb, &i, pos);
1788	1787	} else {
1789	1788	num_written = __btrfs_buffered_write(file, &i, pos);
1790	1789	if (num_written > 0)
...	...	@@ -1188,8 +1188,7 @@
1188	1188	{
1189	1189	struct file *file = iocb->ki_filp;
1190	1190	struct address_space *mapping = file->f_mapping;
1191		- size_t count = 0;
1192		- size_t ocount = 0;
	1191	+ size_t count;
1193	1192	ssize_t written = 0;
1194	1193	ssize_t written_buffered = 0;
1195	1194	struct inode *inode = mapping->host;
...	...	@@ -1208,7 +1207,8 @@
1208	1207
1209	1208	WARN_ON(iocb->ki_pos != pos);
1210	1209
1211		- count = ocount = iov_length(iov, nr_segs);
	1210	+ count = iov_length(iov, nr_segs);
	1211	+ iov_iter_init(&i, WRITE, iov, nr_segs, count);
1212	1212	mutex_lock(&inode->i_mutex);
1213	1213
1214	1214	/* We can write back this queue in page reclaim */
1215	1215
...	...	@@ -1217,11 +1217,11 @@
1217	1217	err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
1218	1218	if (err)
1219	1219	goto out;
1220		- iov_iter_init(&i, WRITE, iov, nr_segs, count);
1221	1220
1222	1221	if (count == 0)
1223	1222	goto out;
1224	1223
	1224	+ iov_iter_truncate(&i, count);
1225	1225	err = file_remove_suid(file);
1226	1226	if (err)
1227	1227	goto out;
...	...	@@ -1231,8 +1231,8 @@
1231	1231	goto out;
1232	1232
1233	1233	if (file->f_flags & O_DIRECT) {
1234		- written = generic_file_direct_write(iocb, &i, pos, count, ocount);
1235		- if (written < 0 \|\| written == count)
	1234	+ written = generic_file_direct_write(iocb, &i, pos);
	1235	+ if (written < 0 \|\| !iov_iter_count(&i))
1236	1236	goto out;
1237	1237
1238	1238	pos += written;
...	...	@@ -1469,8 +1469,7 @@
1469	1469
1470	1470	res = generic_write_checks(file, ppos, &count, 0);
1471	1471	if (!res) {
1472		- if (iter->count > count)
1473		- iter->count = count;
	1472	+ iov_iter_truncate(iter, count);
1474	1473	res = fuse_direct_io(io, iter, ppos, FUSE_DIO_WRITE);
1475	1474	}
1476	1475
...	...	@@ -2896,8 +2895,7 @@
2896	2895	if (offset >= i_size)
2897	2896	return 0;
2898	2897	count = min_t(loff_t, count, fuse_round_up(i_size - offset));
2899		- if (iter->count > count)
2900		- iter->count = count;
	2898	+ iov_iter_truncate(iter, count);
2901	2899	}
2902	2900
2903	2901	io = kmalloc(sizeof(struct fuse_io_priv), GFP_KERNEL);
...	...	@@ -2241,7 +2241,6 @@
2241	2241	int ret, direct_io, appending, rw_level, have_alloc_sem = 0;
2242	2242	int can_do_direct, has_refcount = 0;
2243	2243	ssize_t written = 0;
2244		- size_t ocount; /* original count */
2245	2244	size_t count; /* after file limit checks */
2246	2245	loff_t old_size, *ppos = &iocb->ki_pos;
2247	2246	u32 old_clusters;
...	...	@@ -2253,6 +2252,9 @@
2253	2252	int unaligned_dio = 0;
2254	2253	struct iov_iter from;
2255	2254
	2255	+ count = iov_length(iov, nr_segs);
	2256	+ iov_iter_init(&from, WRITE, iov, nr_segs, count);
	2257	+
2256	2258	trace_ocfs2_file_aio_write(inode, file, file->f_path.dentry,
2257	2259	(unsigned long long)OCFS2_I(inode)->ip_blkno,
2258	2260	file->f_path.dentry->d_name.len,
2259	2261
2260	2262
...	...	@@ -2355,16 +2357,14 @@
2355	2357	/* communicate with ocfs2_dio_end_io */
2356	2358	ocfs2_iocb_set_rw_locked(iocb, rw_level);
2357	2359
2358		- count = ocount = iov_length(iov, nr_segs);
2359	2360	ret = generic_write_checks(file, ppos, &count,
2360	2361	S_ISBLK(inode->i_mode));
2361	2362	if (ret)
2362	2363	goto out_dio;
2363	2364
2364		- iov_iter_init(&from, WRITE, iov, nr_segs, count);
	2365	+ iov_iter_truncate(&from, count);
2365	2366	if (direct_io) {
2366		- written = generic_file_direct_write(iocb, &from, *ppos,
2367		- count, ocount);
	2367	+ written = generic_file_direct_write(iocb, &from, *ppos);
2368	2368	if (written < 0) {
2369	2369	ret = written;
2370	2370	goto out_dio;
...	...	@@ -626,7 +626,7 @@
626	626	const struct iovec *iovp,
627	627	unsigned long nr_segs,
628	628	loff_t pos,
629		- size_t ocount)
	629	+ size_t count)
630	630	{
631	631	struct file *file = iocb->ki_filp;
632	632	struct address_space *mapping = file->f_mapping;
...	...	@@ -634,7 +634,6 @@
634	634	struct xfs_inode *ip = XFS_I(inode);
635	635	struct xfs_mount *mp = ip->i_mount;
636	636	ssize_t ret = 0;
637		- size_t count = ocount;
638	637	int unaligned_io = 0;
639	638	int iolock;
640	639	struct xfs_buftarg *target = XFS_IS_REALTIME_INODE(ip) ?
...	...	@@ -645,6 +644,8 @@
645	644	if ((pos \| count) & target->bt_logical_sectormask)
646	645	return -XFS_ERROR(EINVAL);
647	646
	647	+ iov_iter_init(&from, WRITE, iovp, nr_segs, count);
	648	+
648	649	/* "unaligned" here means not aligned to a filesystem block */
649	650	if ((pos & mp->m_blockmask) \|\| ((pos + count) & mp->m_blockmask))
650	651	unaligned_io = 1;
...	...	@@ -676,6 +677,7 @@
676	677	ret = xfs_file_aio_write_checks(file, &pos, &count, &iolock);
677	678	if (ret)
678	679	goto out;
	680	+ iov_iter_truncate(&from, count);
679	681
680	682	if (mapping->nrpages) {
681	683	ret = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
...	...	@@ -697,8 +699,7 @@
697	699	}
698	700
699	701	trace_xfs_file_direct_write(ip, count, iocb->ki_pos, 0);
700		- iov_iter_init(&from, WRITE, iovp, nr_segs, count);
701		- ret = generic_file_direct_write(iocb, &from, pos, count, ocount);
	702	+ ret = generic_file_direct_write(iocb, &from, pos);
702	703
703	704	out:
704	705	xfs_rw_iunlock(ip, iolock);
...	...	@@ -2407,8 +2407,7 @@
2407	2407	extern ssize_t generic_file_read_iter(struct kiocb , struct iov_iter );
2408	2408	extern ssize_t __generic_file_aio_write(struct kiocb , const struct iovec , unsigned long);
2409	2409	extern ssize_t generic_file_aio_write(struct kiocb , const struct iovec , unsigned long, loff_t);
2410		-extern ssize_t generic_file_direct_write(struct kiocb , struct iov_iter ,
2411		- loff_t, size_t, size_t);
	2410	+extern ssize_t generic_file_direct_write(struct kiocb , struct iov_iter , loff_t);
2412	2411	extern ssize_t generic_perform_write(struct file , struct iov_iter , loff_t);
2413	2412	extern ssize_t do_sync_read(struct file filp, char __user buf, size_t len, loff_t *ppos);
2414	2413	extern ssize_t do_sync_write(struct file filp, const char __user buf, size_t len, loff_t *ppos);
...	...	@@ -82,6 +82,12 @@
82	82	return i->count;
83	83	}
84	84
	85	+static inline void iov_iter_truncate(struct iov_iter *i, size_t count)
	86	+{
	87	+ if (i->count > count)
	88	+ i->count = count;
	89	+}
	90	+
85	91	int memcpy_fromiovec(unsigned char kdata, struct iovec iov, int len);
86	92	int memcpy_toiovec(struct iovec iov, unsigned char kdata, int len);
87	93
...	...	@@ -2345,8 +2345,7 @@
2345	2345	EXPORT_SYMBOL(pagecache_write_end);
2346	2346
2347	2347	ssize_t
2348		-generic_file_direct_write(struct kiocb iocb, struct iov_iter from,
2349		- loff_t pos, size_t count, size_t ocount)
	2348	+generic_file_direct_write(struct kiocb iocb, struct iov_iter from, loff_t pos)
2350	2349	{
2351	2350	struct file *file = iocb->ki_filp;
2352	2351	struct address_space *mapping = file->f_mapping;
...	...	@@ -2356,10 +2355,7 @@
2356	2355	pgoff_t end;
2357	2356	struct iov_iter data;
2358	2357
2359		- if (count != ocount)
2360		- from->nr_segs = iov_shorten((struct iovec *)from->iov, from->nr_segs, count);
2361		-
2362		- write_len = iov_length(from->iov, from->nr_segs);
	2358	+ write_len = iov_iter_count(from);
2363	2359	end = (pos + write_len - 1) >> PAGE_CACHE_SHIFT;
2364	2360
2365	2361	written = filemap_write_and_wait_range(mapping, pos, pos + write_len - 1);
...	...	@@ -2568,7 +2564,6 @@
2568	2564	{
2569	2565	struct file *file = iocb->ki_filp;
2570	2566	struct address_space * mapping = file->f_mapping;
2571		- size_t ocount; /* original count */
2572	2567	size_t count; /* after file limit checks */
2573	2568	struct inode *inode = mapping->host;
2574	2569	loff_t pos = iocb->ki_pos;
...	...	@@ -2577,7 +2572,8 @@
2577	2572	ssize_t status;
2578	2573	struct iov_iter from;
2579	2574
2580		- count = ocount = iov_length(iov, nr_segs);
	2575	+ count = iov_length(iov, nr_segs);
	2576	+ iov_iter_init(&from, WRITE, iov, nr_segs, count);
2581	2577
2582	2578	/* We can write back this queue in page reclaim */
2583	2579	current->backing_dev_info = mapping->backing_dev_info;
...	...	@@ -2588,6 +2584,8 @@
2588	2584	if (count == 0)
2589	2585	goto out;
2590	2586
	2587	+ iov_iter_truncate(&from, count);
	2588	+
2591	2589	err = file_remove_suid(file);
2592	2590	if (err)
2593	2591	goto out;
2594	2592
...	...	@@ -2596,14 +2594,11 @@
2596	2594	if (err)
2597	2595	goto out;
2598	2596
2599		- iov_iter_init(&from, WRITE, iov, nr_segs, count);
2600		-
2601	2597	/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
2602	2598	if (unlikely(file->f_flags & O_DIRECT)) {
2603	2599	loff_t endbyte;
2604	2600
2605		- written = generic_file_direct_write(iocb, &from, pos,
2606		- count, ocount);
	2601	+ written = generic_file_direct_write(iocb, &from, pos);
2607	2602	if (written < 0 \|\| written == count)
2608	2603	goto out;
2609	2604