Merge tag 'regmap-3.4' into regmap-stride

regmap: Last minute bug fix for 3.4

This is a last minute bug fix that was only just noticed since the code
path that's being exercised here is one that is fairly rarely used.  The
changelog for the change itself is extremely clear and the code itself
is obvious to inspection so should be pretty safe.

Conflicts:
	drivers/base/regmap/regmap.c (overlap between the fix and stride code)

1 files changed, 112 insertions, 17 deletions

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index a841868bf9c..504e61b7fd7 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -194,10 +194,6 @@ int fuse_open_common(struct inode *inode, struct file *file, bool isdir)
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	int err;
 
-	/* VFS checks this, but only _after_ ->open() */
-	if (file->f_flags & O_DIRECT)
-		return -EINVAL;
-
 	err = generic_file_open(inode, file);
 	if (err)
 		return err;
@@ -932,17 +928,23 @@ static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 	struct file *file = iocb->ki_filp;
 	struct address_space *mapping = file->f_mapping;
 	size_t count = 0;
+	size_t ocount = 0;
 	ssize_t written = 0;
+	ssize_t written_buffered = 0;
 	struct inode *inode = mapping->host;
 	ssize_t err;
 	struct iov_iter i;
+	loff_t endbyte = 0;
 
 	WARN_ON(iocb->ki_pos != pos);
 
-	err = generic_segment_checks(iov, &nr_segs, &count, VERIFY_READ);
+	ocount = 0;
+	err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
 	if (err)
 		return err;
 
+	count = ocount;
+
 	mutex_lock(&inode->i_mutex);
 	vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
 
@@ -962,11 +964,41 @@ static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 
 	file_update_time(file);
 
-	iov_iter_init(&i, iov, nr_segs, count, 0);
-	written = fuse_perform_write(file, mapping, &i, pos);
-	if (written >= 0)
-		iocb->ki_pos = pos + written;
+	if (file->f_flags & O_DIRECT) {
+		written = generic_file_direct_write(iocb, iov, &nr_segs,
+						    pos, &iocb->ki_pos,
+						    count, ocount);
+		if (written < 0 || written == count)
+			goto out;
+
+		pos += written;
+		count -= written;
 
+		iov_iter_init(&i, iov, nr_segs, count, written);
+		written_buffered = fuse_perform_write(file, mapping, &i, pos);
+		if (written_buffered < 0) {
+			err = written_buffered;
+			goto out;
+		}
+		endbyte = pos + written_buffered - 1;
+
+		err = filemap_write_and_wait_range(file->f_mapping, pos,
+						   endbyte);
+		if (err)
+			goto out;
+
+		invalidate_mapping_pages(file->f_mapping,
+					 pos >> PAGE_CACHE_SHIFT,
+					 endbyte >> PAGE_CACHE_SHIFT);
+
+		written += written_buffered;
+		iocb->ki_pos = pos + written_buffered;
+	} else {
+		iov_iter_init(&i, iov, nr_segs, count, 0);
+		written = fuse_perform_write(file, mapping, &i, pos);
+		if (written >= 0)
+			iocb->ki_pos = pos + written;
+	}
 out:
 	current->backing_dev_info = NULL;
 	mutex_unlock(&inode->i_mutex);
@@ -1101,30 +1133,41 @@ static ssize_t fuse_direct_read(struct file *file, char __user *buf,
 	return res;
 }
 
-static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
-				 size_t count, loff_t *ppos)
+static ssize_t __fuse_direct_write(struct file *file, const char __user *buf,
+				   size_t count, loff_t *ppos)
 {
 	struct inode *inode = file->f_path.dentry->d_inode;
 	ssize_t res;
 
-	if (is_bad_inode(inode))
-		return -EIO;
-
-	/* Don't allow parallel writes to the same file */
-	mutex_lock(&inode->i_mutex);
 	res = generic_write_checks(file, ppos, &count, 0);
 	if (!res) {
 		res = fuse_direct_io(file, buf, count, ppos, 1);
 		if (res > 0)
 			fuse_write_update_size(inode, *ppos);
 	}
-	mutex_unlock(&inode->i_mutex);
 
 	fuse_invalidate_attr(inode);
 
 	return res;
 }
 
+static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
+				 size_t count, loff_t *ppos)
+{
+	struct inode *inode = file->f_path.dentry->d_inode;
+	ssize_t res;
+
+	if (is_bad_inode(inode))
+		return -EIO;
+
+	/* Don't allow parallel writes to the same file */
+	mutex_lock(&inode->i_mutex);
+	res = __fuse_direct_write(file, buf, count, ppos);
+	mutex_unlock(&inode->i_mutex);
+
+	return res;
+}
+
 static void fuse_writepage_free(struct fuse_conn *fc, struct fuse_req *req)
 {
 	__free_page(req->pages[0]);
@@ -2077,6 +2120,57 @@ int fuse_notify_poll_wakeup(struct fuse_conn *fc,
 	return 0;
 }
 
+static ssize_t fuse_loop_dio(struct file *filp, const struct iovec *iov,
+			     unsigned long nr_segs, loff_t *ppos, int rw)
+{
+	const struct iovec *vector = iov;
+	ssize_t ret = 0;
+
+	while (nr_segs > 0) {
+		void __user *base;
+		size_t len;
+		ssize_t nr;
+
+		base = vector->iov_base;
+		len = vector->iov_len;
+		vector++;
+		nr_segs--;
+
+		if (rw == WRITE)
+			nr = __fuse_direct_write(filp, base, len, ppos);
+		else
+			nr = fuse_direct_read(filp, base, len, ppos);
+
+		if (nr < 0) {
+			if (!ret)
+				ret = nr;
+			break;
+		}
+		ret += nr;
+		if (nr != len)
+			break;
+	}
+
+	return ret;
+}
+
+
+static ssize_t
+fuse_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
+			loff_t offset, unsigned long nr_segs)
+{
+	ssize_t ret = 0;
+	struct file *file = NULL;
+	loff_t pos = 0;
+
+	file = iocb->ki_filp;
+	pos = offset;
+
+	ret = fuse_loop_dio(file, iov, nr_segs, &pos, rw);
+
+	return ret;
+}
+
 static const struct file_operations fuse_file_operations = {
 	.llseek		= fuse_file_llseek,
 	.read		= do_sync_read,
@@ -2120,6 +2214,7 @@ static const struct address_space_operations fuse_file_aops  = {
 	.readpages	= fuse_readpages,
 	.set_page_dirty	= __set_page_dirty_nobuffers,
 	.bmap		= fuse_bmap,
+	.direct_IO	= fuse_direct_IO,
 };
 
 void fuse_init_file_inode(struct inode *inode)