[PATCH 17/22] fs: add read_iter and write_iter to several file systems

[PATCH 17/22] fs: add read_iter and write_iter to several file systems

[Dave Kleikamp]

These are the simple ones.

File systems that use generic_file_aio_read() and generic_file_aio_write()
can trivially support generic_file_read_iter() and generic_file_write_iter().

This patch adds those file_operations for 9p, ext2, ext3, fat, hfs, hfsplus,
jfs, nilfs2, and reiserfs.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
Cc: v9fs-developer@lists.sourceforge.net
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: linux-ext4@vger.kernel.org
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: jfs-discussion@lists.sourceforge.net
Cc: linux-nilfs@vger.kernel.org
Cc: reiserfs-devel@vger.kernel.org
---
 fs/9p/vfs_file.c   | 4 ++++
 fs/ext2/file.c     | 2 ++
 fs/ext3/file.c     | 2 ++
 fs/fat/file.c      | 2 ++
 fs/hfs/inode.c     | 2 ++
 fs/hfsplus/inode.c | 2 ++
 fs/jfs/file.c      | 2 ++
 fs/nilfs2/file.c   | 2 ++
 fs/reiserfs/file.c | 2 ++
 9 files changed, 20 insertions(+)

diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index c2483e9..d19458b 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -748,6 +748,8 @@ const struct file_operations v9fs_cached_file_operations = {
 	.write = v9fs_cached_file_write,
 	.aio_read = generic_file_aio_read,
 	.aio_write = generic_file_aio_write,
+	.read_iter = generic_file_read_iter,
+	.write_iter = generic_file_write_iter,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 	.lock = v9fs_file_lock,
@@ -761,6 +763,8 @@ const struct file_operations v9fs_cached_file_operations_dotl = {
 	.write = v9fs_cached_file_write,
 	.aio_read = generic_file_aio_read,
 	.aio_write = generic_file_aio_write,
+	.read_iter = generic_file_read_iter,
+	.write_iter = generic_file_write_iter,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 	.lock = v9fs_file_lock_dotl,
diff --git a/fs/ext2/file.c b/fs/ext2/file.c
index a5b3a5d..eee8f86 100644
--- a/fs/ext2/file.c
+++ b/fs/ext2/file.c
@@ -66,6 +66,8 @@ const struct file_operations ext2_file_operations = {
 	.write		= do_sync_write,
 	.aio_read	= generic_file_aio_read,
 	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.unlocked_ioctl = ext2_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ext2_compat_ioctl,
diff --git a/fs/ext3/file.c b/fs/ext3/file.c
index 25cb413..86828f7 100644
--- a/fs/ext3/file.c
+++ b/fs/ext3/file.c
@@ -54,6 +54,8 @@ const struct file_operations ext3_file_operations = {
 	.write		= do_sync_write,
 	.aio_read	= generic_file_aio_read,
 	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.unlocked_ioctl	= ext3_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ext3_compat_ioctl,
diff --git a/fs/fat/file.c b/fs/fat/file.c
index a62e0ec..250d1b7 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -166,6 +166,8 @@ const struct file_operations fat_file_operations = {
 	.write		= do_sync_write,
 	.aio_read	= generic_file_aio_read,
 	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.release	= fat_file_release,
 	.unlocked_ioctl	= fat_generic_ioctl,
diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c
index 986cb91..f750dbe 100644
--- a/fs/hfs/inode.c
+++ b/fs/hfs/inode.c
@@ -656,8 +656,10 @@ static const struct file_operations hfs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
 	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= do_sync_write,
 	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.splice_read	= generic_file_splice_read,
 	.fsync		= hfs_file_fsync,
diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c
index 94fc092..0191a0d 100644
--- a/fs/hfsplus/inode.c
+++ b/fs/hfsplus/inode.c
@@ -369,8 +369,10 @@ static const struct file_operations hfsplus_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
 	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= do_sync_write,
 	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.splice_read	= generic_file_splice_read,
 	.fsync		= hfsplus_file_fsync,
diff --git a/fs/jfs/file.c b/fs/jfs/file.c
index 9d3afd1..a49ede70 100644
--- a/fs/jfs/file.c
+++ b/fs/jfs/file.c
@@ -151,6 +151,8 @@ const struct file_operations jfs_file_operations = {
 	.read		= do_sync_read,
 	.aio_read	= generic_file_aio_read,
 	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.splice_read	= generic_file_splice_read,
 	.splice_write	= generic_file_splice_write,
diff --git a/fs/nilfs2/file.c b/fs/nilfs2/file.c
index 16f35f7..f4c58c9 100644
--- a/fs/nilfs2/file.c
+++ b/fs/nilfs2/file.c
@@ -155,6 +155,8 @@ const struct file_operations nilfs_file_operations = {
 	.write		= do_sync_write,
 	.aio_read	= generic_file_aio_read,
 	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.unlocked_ioctl	= nilfs_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= nilfs_compat_ioctl,
diff --git a/fs/reiserfs/file.c b/fs/reiserfs/file.c
index 8375c92..8f86c2b 100644
--- a/fs/reiserfs/file.c
+++ b/fs/reiserfs/file.c
@@ -306,6 +306,8 @@ const struct file_operations reiserfs_file_operations = {
 	.fsync = reiserfs_sync_file,
 	.aio_read = generic_file_aio_read,
 	.aio_write = generic_file_aio_write,
+	.read_iter = generic_file_read_iter,
+	.write_iter = generic_file_write_iter,
 	.splice_read = generic_file_splice_read,
 	.splice_write = generic_file_splice_write,
 	.llseek = generic_file_llseek,
-- 
1.7.12.3

[PATCH 19/22] ext4: add support for read_iter and write_iter

[Dave Kleikamp]

use the generic_file_read_iter(), create ext4_file_write_iter() based on
ext4_file_write(), and make ext4_file_write() a wrapper around
ext4_file_write_iter().

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: linux-ext4@vger.kernel.org
---
 fs/ext4/file.c | 49 ++++++++++++++++++++++++++++++++++---------------
 1 file changed, 34 insertions(+), 15 deletions(-)

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index bf3966b..4a49e91 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -72,12 +72,11 @@ 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 *iter, loff_t pos)
 {
 	struct super_block *sb = inode->i_sb;
 	int blockmask = sb->s_blocksize - 1;
-	size_t count = iov_length(iov, nr_segs);
+	size_t count = iov_iter_count(iter);
 	loff_t final_size = pos + count;
 
 	if (pos >= inode->i_size)
@@ -90,8 +89,8 @@ ext4_unaligned_aio(struct inode *inode, const struct iovec *iov,
 }
 
 static ssize_t
-ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov,
-		    unsigned long nr_segs, loff_t pos)
+ext4_file_dio_write(struct kiocb *iocb, struct iov_iter *iter,
+		    loff_t pos)
 {
 	struct file *file = iocb->ki_filp;
 	struct inode *inode = file->f_mapping->host;
@@ -99,11 +98,11 @@ ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov,
 	int unaligned_aio = 0;
 	ssize_t ret;
 	int overwrite = 0;
-	size_t length = iov_length(iov, nr_segs);
+	size_t length = iov_iter_count(iter);
 
 	if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) &&
 	    !is_sync_kiocb(iocb))
-		unaligned_aio = ext4_unaligned_aio(inode, iov, nr_segs, pos);
+		unaligned_aio = ext4_unaligned_aio(inode, iter, pos);
 
 	/* Unaligned direct AIO must be serialized; see comment above */
 	if (unaligned_aio) {
@@ -152,7 +151,7 @@ ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov,
 			overwrite = 1;
 	}
 
-	ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
+	ret = __generic_file_write_iter(iocb, iter, &iocb->ki_pos);
 	mutex_unlock(&inode->i_mutex);
 
 	if (ret > 0 || ret == -EIOCBQUEUED) {
@@ -171,8 +170,7 @@ ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov,
 }
 
 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 *iter, loff_t pos)
 {
 	struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
 	ssize_t ret;
@@ -184,26 +182,45 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
 
 	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
 		struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
-		size_t length = iov_length(iov, nr_segs);
+		size_t length = iov_iter_count(iter);
 
 		if ((pos > sbi->s_bitmap_maxbytes ||
 		    (pos == sbi->s_bitmap_maxbytes && length > 0)))
 			return -EFBIG;
 
 		if (pos + length > sbi->s_bitmap_maxbytes) {
-			nr_segs = iov_shorten((struct iovec *)iov, nr_segs,
-					      sbi->s_bitmap_maxbytes - pos);
+			ret = iov_iter_shorten(iter,
+					       sbi->s_bitmap_maxbytes - pos);
+			if (ret)
+				return ret;
 		}
 	}
 
 	if (unlikely(iocb->ki_filp->f_flags & O_DIRECT))
-		ret = ext4_file_dio_write(iocb, iov, nr_segs, pos);
+		ret = ext4_file_dio_write(iocb, iter, pos);
 	else
-		ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
+		ret = generic_file_write_iter(iocb, iter, pos);
 
 	return ret;
 }
 
+static ssize_t
+ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
+		unsigned long nr_segs, loff_t pos)
+{
+	struct iov_iter i;
+	int ret;
+	size_t count;
+
+	ret = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE);
+	if (ret)
+		return ret;
+
+	iov_iter_init(&i, iov, nr_segs, count, 0);
+
+	return ext4_file_write_iter(iocb, &i, pos);
+}
+
 static const struct vm_operations_struct ext4_file_vm_ops = {
 	.fault		= filemap_fault,
 	.page_mkwrite   = ext4_page_mkwrite,
@@ -310,6 +327,8 @@ const struct file_operations ext4_file_operations = {
 	.write		= do_sync_write,
 	.aio_read	= generic_file_aio_read,
 	.aio_write	= ext4_file_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= ext4_file_write_iter,
 	.unlocked_ioctl = ext4_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ext4_compat_ioctl,
-- 
1.7.12.3