Merge branch '9p-iov_iter' into for-next

5 files changed, 139 insertions, 366 deletions

diff --git a/fs/9p/v9fs_vfs.h b/fs/9p/v9fs_vfs.h
index b83ebfbf3fdc..5a0db6dec8d1 100644
--- a/fs/9p/v9fs_vfs.h
+++ b/fs/9p/v9fs_vfs.h
@@ -68,14 +68,10 @@ int v9fs_file_open(struct inode *inode, struct file *file);
 void v9fs_inode2stat(struct inode *inode, struct p9_wstat *stat);
 int v9fs_uflags2omode(int uflags, int extended);
 
-ssize_t v9fs_file_readn(struct file *, char *, char __user *, u32, u64);
-ssize_t v9fs_fid_readn(struct p9_fid *, char *, char __user *, u32, u64);
 void v9fs_blank_wstat(struct p9_wstat *wstat);
 int v9fs_vfs_setattr_dotl(struct dentry *, struct iattr *);
 int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
 			 int datasync);
-ssize_t v9fs_file_write_internal(struct inode *, struct p9_fid *,
-				 const char __user *, size_t, loff_t *, int);
 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode);
 int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode);
 static inline void v9fs_invalidate_inode_attr(struct inode *inode)
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index ff1a5bac4200..2e38f9a5b472 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -51,12 +51,11 @@
  */
 static int v9fs_fid_readpage(struct p9_fid *fid, struct page *page)
 {
-	int retval;
-	loff_t offset;
-	char *buffer;
-	struct inode *inode;
+	struct inode *inode = page->mapping->host;
+	struct bio_vec bvec = {.bv_page = page, .bv_len = PAGE_SIZE};
+	struct iov_iter to;
+	int retval, err;
 
-	inode = page->mapping->host;
 	p9_debug(P9_DEBUG_VFS, "\n");
 
 	BUG_ON(!PageLocked(page));
@@ -65,16 +64,16 @@ static int v9fs_fid_readpage(struct p9_fid *fid, struct page *page)
 	if (retval == 0)
 		return retval;
 
-	buffer = kmap(page);
-	offset = page_offset(page);
+	iov_iter_bvec(&to, ITER_BVEC | READ, &bvec, 1, PAGE_SIZE);
 
-	retval = v9fs_fid_readn(fid, buffer, NULL, PAGE_CACHE_SIZE, offset);
-	if (retval < 0) {
+	retval = p9_client_read(fid, page_offset(page), &to, &err);
+	if (err) {
 		v9fs_uncache_page(inode, page);
+		retval = err;
 		goto done;
 	}
 
-	memset(buffer + retval, 0, PAGE_CACHE_SIZE - retval);
+	zero_user(page, retval, PAGE_SIZE - retval);
 	flush_dcache_page(page);
 	SetPageUptodate(page);
 
@@ -82,7 +81,6 @@ static int v9fs_fid_readpage(struct p9_fid *fid, struct page *page)
 	retval = 0;
 
 done:
-	kunmap(page);
 	unlock_page(page);
 	return retval;
 }
@@ -161,41 +159,32 @@ static void v9fs_invalidate_page(struct page *page, unsigned int offset,
 
 static int v9fs_vfs_writepage_locked(struct page *page)
 {
-	char *buffer;
-	int retval, len;
-	loff_t offset, size;
-	mm_segment_t old_fs;
-	struct v9fs_inode *v9inode;
 	struct inode *inode = page->mapping->host;
+	struct v9fs_inode *v9inode = V9FS_I(inode);
+	loff_t size = i_size_read(inode);
+	struct iov_iter from;
+	struct bio_vec bvec;
+	int err, len;
 
-	v9inode = V9FS_I(inode);
-	size = i_size_read(inode);
 	if (page->index == size >> PAGE_CACHE_SHIFT)
 		len = size & ~PAGE_CACHE_MASK;
 	else
 		len = PAGE_CACHE_SIZE;
 
-	set_page_writeback(page);
-
-	buffer = kmap(page);
-	offset = page_offset(page);
+	bvec.bv_page = page;
+	bvec.bv_offset = 0;
+	bvec.bv_len = len;
+	iov_iter_bvec(&from, ITER_BVEC | WRITE, &bvec, 1, len);
 
-	old_fs = get_fs();
-	set_fs(get_ds());
 	/* We should have writeback_fid always set */
 	BUG_ON(!v9inode->writeback_fid);
 
-	retval = v9fs_file_write_internal(inode,
-					  v9inode->writeback_fid,
-					  (__force const char __user *)buffer,
-					  len, &offset, 0);
-	if (retval > 0)
-		retval = 0;
+	set_page_writeback(page);
+
+	p9_client_write(v9inode->writeback_fid, page_offset(page), &from, &err);
 
-	set_fs(old_fs);
-	kunmap(page);
 	end_page_writeback(page);
-	return retval;
+	return err;
 }
 
 static int v9fs_vfs_writepage(struct page *page, struct writeback_control *wbc)
@@ -261,16 +250,21 @@ static int v9fs_launder_page(struct page *page)
 static ssize_t
 v9fs_direct_IO(int rw, struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
 {
-	/*
-	 * FIXME
-	 * Now that we do caching with cache mode enabled, We need
-	 * to support direct IO
-	 */
-	p9_debug(P9_DEBUG_VFS, "v9fs_direct_IO: v9fs_direct_IO (%pD) off/no(%lld/%lu) EINVAL\n",
-		 iocb->ki_filp,
-		 (long long)pos, iter->nr_segs);
-
-	return -EINVAL;
+	struct file *file = iocb->ki_filp;
+	ssize_t n;
+	int err = 0;
+	if (rw & WRITE) {
+		n = p9_client_write(file->private_data, pos, iter, &err);
+		if (n) {
+			struct inode *inode = file_inode(file);
+			loff_t i_size = i_size_read(inode);
+			if (pos + n > i_size)
+				inode_add_bytes(inode, pos + n - i_size);
+		}
+	} else {
+		n = p9_client_read(file->private_data, pos, iter, &err);
+	}
+	return n ? n : err;
 }
 
 static int v9fs_write_begin(struct file *filp, struct address_space *mapping,
diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c
index 4f1151088ebe..76c3b1ab6361 100644
--- a/fs/9p/vfs_dir.c
+++ b/fs/9p/vfs_dir.c
@@ -33,6 +33,7 @@
 #include <linux/inet.h>
 #include <linux/idr.h>
 #include <linux/slab.h>
+#include <linux/uio.h>
 #include <net/9p/9p.h>
 #include <net/9p/client.h>
 
@@ -115,6 +116,7 @@ static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx)
 	int buflen;
 	int reclen = 0;
 	struct p9_rdir *rdir;
+	struct kvec kvec;
 
 	p9_debug(P9_DEBUG_VFS, "name %pD\n", file);
 	fid = file->private_data;
@@ -124,16 +126,21 @@ static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx)
 	rdir = v9fs_alloc_rdir_buf(file, buflen);
 	if (!rdir)
 		return -ENOMEM;
+	kvec.iov_base = rdir->buf;
+	kvec.iov_len = buflen;
 
 	while (1) {
 		if (rdir->tail == rdir->head) {
-			err = v9fs_file_readn(file, rdir->buf, NULL,
-							buflen, ctx->pos);
-			if (err <= 0)
+			struct iov_iter to;
+			int n;
+			iov_iter_kvec(&to, READ | ITER_KVEC, &kvec, 1, buflen);
+			n = p9_client_read(file->private_data, ctx->pos, &to,
+					   &err);
+			if (err)
 				return err;
 
 			rdir->head = 0;
-			rdir->tail = err;
+			rdir->tail = n;
 		}
 		while (rdir->head < rdir->tail) {
 			p9stat_init(&st);
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index b40133796b87..55cc9c80e187 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -36,6 +36,8 @@
 #include <linux/utsname.h>
 #include <asm/uaccess.h>
 #include <linux/idr.h>
+#include <linux/uio.h>
+#include <linux/slab.h>
 #include <net/9p/9p.h>
 #include <net/9p/client.h>
 
@@ -285,6 +287,7 @@ static int v9fs_file_getlock(struct file *filp, struct file_lock *fl)
 			fl->fl_end = glock.start + glock.length - 1;
 		fl->fl_pid = glock.proc_id;
 	}
+	kfree(glock.client_id);
 	return res;
 }
 
@@ -364,63 +367,6 @@ out_err:
 }
 
 /**
- * v9fs_fid_readn - read from a fid
- * @fid: fid to read
- * @data: data buffer to read data into
- * @udata: user data buffer to read data into
- * @count: size of buffer
- * @offset: offset at which to read data
- *
- */
-ssize_t
-v9fs_fid_readn(struct p9_fid *fid, char *data, char __user *udata, u32 count,
-	       u64 offset)
-{
-	int n, total, size;
-
-	p9_debug(P9_DEBUG_VFS, "fid %d offset %llu count %d\n",
-		 fid->fid, (long long unsigned)offset, count);
-	n = 0;
-	total = 0;
-	size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ;
-	do {
-		n = p9_client_read(fid, data, udata, offset, count);
-		if (n <= 0)
-			break;
-
-		if (data)
-			data += n;
-		if (udata)
-			udata += n;
-
-		offset += n;
-		count -= n;
-		total += n;
-	} while (count > 0 && n == size);
-
-	if (n < 0)
-		total = n;
-
-	return total;
-}
-
-/**
- * v9fs_file_readn - read from a file
- * @filp: file pointer to read
- * @data: data buffer to read data into
- * @udata: user data buffer to read data into
- * @count: size of buffer
- * @offset: offset at which to read data
- *
- */
-ssize_t
-v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count,
-	       u64 offset)
-{
-	return v9fs_fid_readn(filp->private_data, data, udata, count, offset);
-}
-
-/**
  * v9fs_file_read - read from a file
  * @filp: file pointer to read
  * @udata: user data buffer to read data into
@@ -430,69 +376,22 @@ v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count,
  */
 
 static ssize_t
-v9fs_file_read(struct file *filp, char __user *udata, size_t count,
-	       loff_t * offset)
+v9fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
-	int ret;
-	struct p9_fid *fid;
-	size_t size;
+	struct p9_fid *fid = iocb->ki_filp->private_data;
+	int ret, err;
 
-	p9_debug(P9_DEBUG_VFS, "count %zu offset %lld\n", count, *offset);
-	fid = filp->private_data;
+	p9_debug(P9_DEBUG_VFS, "count %zu offset %lld\n",
+		 iov_iter_count(to), iocb->ki_pos);
 
-	size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ;
-	if (count > size)
-		ret = v9fs_file_readn(filp, NULL, udata, count, *offset);
-	else
-		ret = p9_client_read(fid, NULL, udata, *offset, count);
-
-	if (ret > 0)
-		*offset += ret;
+	ret = p9_client_read(fid, iocb->ki_pos, to, &err);
+	if (!ret)
+		return err;
 
+	iocb->ki_pos += ret;
 	return ret;
 }
 
-ssize_t
-v9fs_file_write_internal(struct inode *inode, struct p9_fid *fid,
-			 const char __user *data, size_t count,
-			 loff_t *offset, int invalidate)
-{
-	int n;
-	loff_t i_size;
-	size_t total = 0;
-	loff_t origin = *offset;
-	unsigned long pg_start, pg_end;
-
-	p9_debug(P9_DEBUG_VFS, "data %p count %d offset %x\n",
-		 data, (int)count, (int)*offset);
-
-	do {
-		n = p9_client_write(fid, NULL, data+total, origin+total, count);
-		if (n <= 0)
-			break;
-		count -= n;
-		total += n;
-	} while (count > 0);
-
-	if (invalidate && (total > 0)) {
-		pg_start = origin >> PAGE_CACHE_SHIFT;
-		pg_end = (origin + total - 1) >> PAGE_CACHE_SHIFT;
-		if (inode->i_mapping && inode->i_mapping->nrpages)
-			invalidate_inode_pages2_range(inode->i_mapping,
-						      pg_start, pg_end);
-		*offset += total;
-		i_size = i_size_read(inode);
-		if (*offset > i_size) {
-			inode_add_bytes(inode, *offset - i_size);
-			i_size_write(inode, *offset);
-		}
-	}
-	if (n < 0)
-		return n;
-
-	return total;
-}
-
 /**
  * v9fs_file_write - write to a file
  * @filp: file pointer to write
@@ -502,35 +401,45 @@ v9fs_file_write_internal(struct inode *inode, struct p9_fid *fid,
  *
  */
 static ssize_t
-v9fs_file_write(struct file *filp, const char __user * data,
-		size_t count, loff_t *offset)
+v9fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
+	struct file *file = iocb->ki_filp;
 	ssize_t retval = 0;
-	loff_t origin = *offset;
+	loff_t origin = iocb->ki_pos;
+	size_t count = iov_iter_count(from);
+	int err = 0;
 
-
-	retval = generic_write_checks(filp, &origin, &count, 0);
+	retval = generic_write_checks(file, &origin, &count, 0);
 	if (retval)
-		goto out;
+		return retval;
+
+	iov_iter_truncate(from, count);
 
-	retval = -EINVAL;
-	if ((ssize_t) count < 0)
-		goto out;
-	retval = 0;
 	if (!count)
-		goto out;
+		return 0;
 
-	retval = v9fs_file_write_internal(file_inode(filp),
-					filp->private_data,
-					data, count, &origin, 1);
-	/* update offset on successful write */
-	if (retval > 0)
-		*offset = origin;
-out:
-	return retval;
+	retval = p9_client_write(file->private_data, origin, from, &err);
+	if (retval > 0) {
+		struct inode *inode = file_inode(file);
+		loff_t i_size;
+		unsigned long pg_start, pg_end;
+		pg_start = origin >> PAGE_CACHE_SHIFT;
+		pg_end = (origin + retval - 1) >> PAGE_CACHE_SHIFT;
+		if (inode->i_mapping && inode->i_mapping->nrpages)
+			invalidate_inode_pages2_range(inode->i_mapping,
+						      pg_start, pg_end);
+		origin += retval;
+		i_size = i_size_read(inode);
+		iocb->ki_pos = origin;
+		if (origin > i_size) {
+			inode_add_bytes(inode, origin - i_size);
+			i_size_write(inode, origin);
+		}
+		return retval;
+	}
+	return err;
 }
 
-
 static int v9fs_file_fsync(struct file *filp, loff_t start, loff_t end,
 			   int datasync)
 {
@@ -657,44 +566,6 @@ out_unlock:
 	return VM_FAULT_NOPAGE;
 }
 
-static ssize_t
-v9fs_direct_read(struct file *filp, char __user *udata, size_t count,
-		 loff_t *offsetp)
-{
-	loff_t size, offset;
-	struct inode *inode;
-	struct address_space *mapping;
-
-	offset = *offsetp;
-	mapping = filp->f_mapping;
-	inode = mapping->host;
-	if (!count)
-		return 0;
-	size = i_size_read(inode);
-	if (offset < size)
-		filemap_write_and_wait_range(mapping, offset,
-					     offset + count - 1);
-
-	return v9fs_file_read(filp, udata, count, offsetp);
-}
-
-/**
- * v9fs_cached_file_read - read from a file
- * @filp: file pointer to read
- * @data: user data buffer to read data into
- * @count: size of buffer
- * @offset: offset at which to read data
- *
- */
-static ssize_t
-v9fs_cached_file_read(struct file *filp, char __user *data, size_t count,
-		      loff_t *offset)
-{
-	if (filp->f_flags & O_DIRECT)
-		return v9fs_direct_read(filp, data, count, offset);
-	return new_sync_read(filp, data, count, offset);
-}
-
 /**
  * v9fs_mmap_file_read - read from a file
  * @filp: file pointer to read
@@ -704,84 +575,12 @@ v9fs_cached_file_read(struct file *filp, char __user *data, size_t count,
  *
  */
 static ssize_t
-v9fs_mmap_file_read(struct file *filp, char __user *data, size_t count,
-		      loff_t *offset)
+v9fs_mmap_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
 	/* TODO: Check if there are dirty pages */
-	return v9fs_file_read(filp, data, count, offset);
+	return v9fs_file_read_iter(iocb, to);
 }
 
-static ssize_t
-v9fs_direct_write(struct file *filp, const char __user * data,
-		  size_t count, loff_t *offsetp)
-{
-	loff_t offset;
-	ssize_t retval;
-	struct inode *inode;
-	struct address_space *mapping;
-
-	offset = *offsetp;
-	mapping = filp->f_mapping;
-	inode = mapping->host;
-	if (!count)
-		return 0;
-
-	mutex_lock(&inode->i_mutex);
-	retval = filemap_write_and_wait_range(mapping, offset,
-					      offset + count - 1);
-	if (retval)
-		goto err_out;
-	/*
-	 * After a write we want buffered reads to be sure to go to disk to get
-	 * the new data.  We invalidate clean cached page from the region we're
-	 * about to write.  We do this *before* the write so that if we fail
-	 * here we fall back to buffered write
-	 */
-	if (mapping->nrpages) {
-		pgoff_t pg_start = offset >> PAGE_CACHE_SHIFT;
-		pgoff_t pg_end   = (offset + count - 1) >> PAGE_CACHE_SHIFT;
-
-		retval = invalidate_inode_pages2_range(mapping,
-							pg_start, pg_end);
-		/*
-		 * If a page can not be invalidated, fall back
-		 * to buffered write.
-		 */
-		if (retval) {
-			if (retval == -EBUSY)
-				goto buff_write;
-			goto err_out;
-		}
-	}
-	retval = v9fs_file_write(filp, data, count, offsetp);
-err_out:
-	mutex_unlock(&inode->i_mutex);
-	return retval;
-
-buff_write:
-	mutex_unlock(&inode->i_mutex);
-	return new_sync_write(filp, data, count, offsetp);
-}
-
-/**
- * v9fs_cached_file_write - write to a file
- * @filp: file pointer to write
- * @data: data buffer to write data from
- * @count: size of buffer
- * @offset: offset at which to write data
- *
- */
-static ssize_t
-v9fs_cached_file_write(struct file *filp, const char __user * data,
-		       size_t count, loff_t *offset)
-{
-
-	if (filp->f_flags & O_DIRECT)
-		return v9fs_direct_write(filp, data, count, offset);
-	return new_sync_write(filp, data, count, offset);
-}
-
-
 /**
  * v9fs_mmap_file_write - write to a file
  * @filp: file pointer to write
@@ -791,14 +590,13 @@ v9fs_cached_file_write(struct file *filp, const char __user * data,
  *
  */
 static ssize_t
-v9fs_mmap_file_write(struct file *filp, const char __user *data,
-		       size_t count, loff_t *offset)
+v9fs_mmap_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
 	/*
 	 * TODO: invalidate mmaps on filp's inode between
 	 * offset and offset+count
 	 */
-	return v9fs_file_write(filp, data, count, offset);
+	return v9fs_file_write_iter(iocb, from);
 }
 
 static void v9fs_mmap_vm_close(struct vm_area_struct *vma)
@@ -843,8 +641,8 @@ static const struct vm_operations_struct v9fs_mmap_file_vm_ops = {
 
 const struct file_operations v9fs_cached_file_operations = {
 	.llseek = generic_file_llseek,
-	.read = v9fs_cached_file_read,
-	.write = v9fs_cached_file_write,
+	.read = new_sync_read,
+	.write = new_sync_write,
 	.read_iter = generic_file_read_iter,
 	.write_iter = generic_file_write_iter,
 	.open = v9fs_file_open,
@@ -856,8 +654,8 @@ const struct file_operations v9fs_cached_file_operations = {
 
 const struct file_operations v9fs_cached_file_operations_dotl = {
 	.llseek = generic_file_llseek,
-	.read = v9fs_cached_file_read,
-	.write = v9fs_cached_file_write,
+	.read = new_sync_read,
+	.write = new_sync_write,
 	.read_iter = generic_file_read_iter,
 	.write_iter = generic_file_write_iter,
 	.open = v9fs_file_open,
@@ -870,8 +668,10 @@ const struct file_operations v9fs_cached_file_operations_dotl = {
 
 const struct file_operations v9fs_file_operations = {
 	.llseek = generic_file_llseek,
-	.read = v9fs_file_read,
-	.write = v9fs_file_write,
+	.read = new_sync_read,
+	.write = new_sync_write,
+	.read_iter = v9fs_file_read_iter,
+	.write_iter = v9fs_file_write_iter,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 	.lock = v9fs_file_lock,
@@ -881,8 +681,10 @@ const struct file_operations v9fs_file_operations = {
 
 const struct file_operations v9fs_file_operations_dotl = {
 	.llseek = generic_file_llseek,
-	.read = v9fs_file_read,
-	.write = v9fs_file_write,
+	.read = new_sync_read,
+	.write = new_sync_write,
+	.read_iter = v9fs_file_read_iter,
+	.write_iter = v9fs_file_write_iter,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 	.lock = v9fs_file_lock_dotl,
@@ -893,8 +695,10 @@ const struct file_operations v9fs_file_operations_dotl = {
 
 const struct file_operations v9fs_mmap_file_operations = {
 	.llseek = generic_file_llseek,
-	.read = v9fs_mmap_file_read,
-	.write = v9fs_mmap_file_write,
+	.read = new_sync_read,
+	.write = new_sync_write,
+	.read_iter = v9fs_mmap_file_read_iter,
+	.write_iter = v9fs_mmap_file_write_iter,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 	.lock = v9fs_file_lock,
@@ -904,8 +708,10 @@ const struct file_operations v9fs_mmap_file_operations = {
 
 const struct file_operations v9fs_mmap_file_operations_dotl = {
 	.llseek = generic_file_llseek,
-	.read = v9fs_mmap_file_read,
-	.write = v9fs_mmap_file_write,
+	.read = new_sync_read,
+	.write = new_sync_write,
+	.read_iter = v9fs_mmap_file_read_iter,
+	.write_iter = v9fs_mmap_file_write_iter,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 	.lock = v9fs_file_lock_dotl,
diff --git a/fs/9p/xattr.c b/fs/9p/xattr.c
index f95e01e058e4..0cf44b6cccd6 100644
--- a/fs/9p/xattr.c
+++ b/fs/9p/xattr.c
@@ -15,6 +15,7 @@
 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/sched.h>
+#include <linux/uio.h>
 #include <net/9p/9p.h>
 #include <net/9p/client.h>
 
@@ -25,50 +26,34 @@ ssize_t v9fs_fid_xattr_get(struct p9_fid *fid, const char *name,
 			   void *buffer, size_t buffer_size)
 {
 	ssize_t retval;
-	int msize, read_count;
-	u64 offset = 0, attr_size;
+	u64 attr_size;
 	struct p9_fid *attr_fid;
+	struct kvec kvec = {.iov_base = buffer, .iov_len = buffer_size};
+	struct iov_iter to;
+	int err;
+
+	iov_iter_kvec(&to, READ | ITER_KVEC, &kvec, 1, buffer_size);
 
 	attr_fid = p9_client_xattrwalk(fid, name, &attr_size);
 	if (IS_ERR(attr_fid)) {
 		retval = PTR_ERR(attr_fid);
 		p9_debug(P9_DEBUG_VFS, "p9_client_attrwalk failed %zd\n",
 			 retval);
-		attr_fid = NULL;
-		goto error;
-	}
-	if (!buffer_size) {
-		/* request to get the attr_size */
-		retval = attr_size;
-		goto error;
+		return retval;
 	}
 	if (attr_size > buffer_size) {
-		retval = -ERANGE;
-		goto error;
-	}
-	msize = attr_fid->clnt->msize;
-	while (attr_size) {
-		if (attr_size > (msize - P9_IOHDRSZ))
-			read_count = msize - P9_IOHDRSZ;
+		if (!buffer_size) /* request to get the attr_size */
+			retval = attr_size;
 		else
-			read_count = attr_size;
-		read_count = p9_client_read(attr_fid, ((char *)buffer)+offset,
-					NULL, offset, read_count);
-		if (read_count < 0) {
-			/* error in xattr read */
-			retval = read_count;
-			goto error;
-		}
-		offset += read_count;
-		attr_size -= read_count;
+			retval = -ERANGE;
+	} else {
+		iov_iter_truncate(&to, attr_size);
+		retval = p9_client_read(attr_fid, 0, &to, &err);
+		if (err)
+			retval = err;
 	}
-	/* Total read xattr bytes */
-	retval = offset;
-error:
-	if (attr_fid)
-		p9_client_clunk(attr_fid);
+	p9_client_clunk(attr_fid);
 	return retval;
-
 }
 
 
@@ -120,8 +105,11 @@ int v9fs_xattr_set(struct dentry *dentry, const char *name,
 int v9fs_fid_xattr_set(struct p9_fid *fid, const char *name,
 		   const void *value, size_t value_len, int flags)
 {
-	u64 offset = 0;
-	int retval, msize, write_count;
+	struct kvec kvec = {.iov_base = (void *)value, .iov_len = value_len};
+	struct iov_iter from;
+	int retval;
+
+	iov_iter_kvec(&from, WRITE | ITER_KVEC, &kvec, 1, value_len);
 
 	p9_debug(P9_DEBUG_VFS, "name = %s value_len = %zu flags = %d\n",
 		 name, value_len, flags);
@@ -135,29 +123,11 @@ int v9fs_fid_xattr_set(struct p9_fid *fid, const char *name,
 	 * On success fid points to xattr
 	 */
 	retval = p9_client_xattrcreate(fid, name, value_len, flags);
-	if (retval < 0) {
+	if (retval < 0)
 		p9_debug(P9_DEBUG_VFS, "p9_client_xattrcreate failed %d\n",
 			 retval);
-		goto err;
-	}
-	msize = fid->clnt->msize;
-	while (value_len) {
-		if (value_len > (msize - P9_IOHDRSZ))
-			write_count = msize - P9_IOHDRSZ;
-		else
-			write_count = value_len;
-		write_count = p9_client_write(fid, ((char *)value)+offset,
-					NULL, offset, write_count);
-		if (write_count < 0) {
-			/* error in xattr write */
-			retval = write_count;
-			goto err;
-		}
-		offset += write_count;
-		value_len -= write_count;
-	}
-	retval = 0;
-err:
+	else
+		p9_client_write(fid, 0, &from, &retval);
 	p9_client_clunk(fid);
 	return retval;
 }