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Commit 9b884164 authored by Al Viro's avatar Al Viro
Browse files

convert ext4 to ->write_iter() 



unfortunately, Ted's changes to ext4_file_write() are *still* an
incomplete fix - playing with rlimits can let you smuggle an
unaligned request past the checks.  So there almost certainly
will be more merge PITA around that place...

[fix from Peter Ujfalusi <peter.ujfalusi@ti.com> folded]

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent a8324754

fs/ext4/file.c

+11 −18
Original line number Diff line number Diff line
@@ -74,26 +74,22 @@ void ext4_unwritten_wait(struct inode *inode) 
 * or one thread will zero the other's data, causing corruption.

 */

static int

ext4_unaligned_aio(struct inode *inode, const struct iovec *iov,

		   unsigned long nr_segs, loff_t pos)

ext4_unaligned_aio(struct inode *inode, struct iov_iter *from, loff_t pos)

{

	struct super_block *sb = inode->i_sb;

	int blockmask = sb->s_blocksize - 1;

	size_t count = iov_length(iov, nr_segs);

	loff_t final_size = pos + count;



	if (pos >= i_size_read(inode))

		return 0;



	if ((pos & blockmask) || (final_size & blockmask))

	if ((pos | iov_iter_alignment(from)) & blockmask)

		return 1;



	return 0;

}



static ssize_t

ext4_file_write(struct kiocb *iocb, const struct iovec *iov,

		unsigned long nr_segs, loff_t pos)

ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)

{

	struct file *file = iocb->ki_filp;

	struct inode *inode = file_inode(iocb->ki_filp);
@@ -101,10 +97,9 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov, 
	struct blk_plug plug;

	int o_direct = file->f_flags & O_DIRECT;

	int overwrite = 0;

	size_t length = iov_length(iov, nr_segs);

	size_t length = iov_iter_count(from);

	ssize_t ret;



	BUG_ON(iocb->ki_pos != pos);

	loff_t pos = iocb->ki_pos;



	/*

	 * Unaligned direct AIO must be serialized; see comment above
@@ -114,7 +109,7 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov, 
	    ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) &&

	    !is_sync_kiocb(iocb) &&

	    (file->f_flags & O_APPEND ||

	     ext4_unaligned_aio(inode, iov, nr_segs, pos))) {

	     ext4_unaligned_aio(inode, from, pos))) {

		aio_mutex = ext4_aio_mutex(inode);

		mutex_lock(aio_mutex);

		ext4_unwritten_wait(inode);
@@ -138,10 +133,8 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov, 
			goto errout;

		}



		if (pos + length > sbi->s_bitmap_maxbytes) {

			nr_segs = iov_shorten((struct iovec *)iov, nr_segs,

					      sbi->s_bitmap_maxbytes - pos);

		}

		if (pos + length > sbi->s_bitmap_maxbytes)

			iov_iter_truncate(from, sbi->s_bitmap_maxbytes - pos);

	}



	if (o_direct) {
@@ -179,7 +172,7 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov, 
		}

	}



	ret = __generic_file_aio_write(iocb, iov, nr_segs);

	ret = __generic_file_write_iter(iocb, from);

	mutex_unlock(&inode->i_mutex);



	if (ret > 0) {
@@ -594,9 +587,9 @@ loff_t ext4_llseek(struct file *file, loff_t offset, int whence) 
const struct file_operations ext4_file_operations = {

	.llseek		= ext4_llseek,

	.read		= new_sync_read,

	.write		= do_sync_write,

	.write		= new_sync_write,

	.read_iter	= generic_file_read_iter,

	.aio_write	= ext4_file_write,

	.write_iter	= ext4_file_write_iter,

	.unlocked_ioctl = ext4_ioctl,

#ifdef CONFIG_COMPAT

	.compat_ioctl	= ext4_compat_ioctl,