[WIP] iter_write/read: splice(2) support for ZFS

Inspired by openzfs/issues/1156 Fixes vpsfreecz/vpsadminos#36 Signed-off-by: Pavel Snajdr <snajpa@snajpa.net>
vpsfreecz · Jun 18, 2020 · 2d6ade8 · 2d6ade8
1 parent 7546fb3
commit 2d6ade8
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Showing 3 changed files with 67 additions and 1 deletion.
diff --git a/module/os/linux/zfs/zfs_vnops.c b/module/os/linux/zfs/zfs_vnops.c
@@ -545,6 +545,7 @@ zfs_read(struct inode *ip, uio_t *uio, int ioflag, cred_t *cr)
 		}
 
 		if (error) {
+			dump_stack();
 			/* convert checksum errors into IO errors */
 			if (error == ECKSUM)
 				error = SET_ERROR(EIO);

diff --git a/module/os/linux/zfs/zpl_file.c b/module/os/linux/zfs/zpl_file.c
@@ -985,6 +985,65 @@ const struct address_space_operations zpl_address_space_operations = {
 	.direct_IO	= zpl_direct_IO,
 };
 
+ssize_t
+zpl_iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
+			  loff_t *ppos, size_t len, unsigned int flags)
+{
+	ssize_t ret;
+	struct inode *ip = out->f_mapping->host;
+	int error;
+	fstrans_cookie_t cookie;
+
+	spl_inode_lock_shared(ip);
+	cookie = spl_fstrans_mark();
+	error = -zfs_holey(ip, SEEK_DATA, ppos);
+	spl_fstrans_unmark(cookie);
+	spl_inode_unlock_shared(ip);
+
+	ret = iter_file_splice_write(pipe, out, ppos, len, flags);
+	printk(KERN_INFO "%s:%d(pipe,out,%llu,%lu,%x):%li\n", __func__, __LINE__,
+						*ppos,len,flags,(long int)ret);
+	return ret;
+}
+
+ssize_t zpl_file_splice_read(struct file *in, loff_t *ppos,
+				 struct pipe_inode_info *pipe, size_t len,
+				 unsigned int flags)
+{
+	cred_t *cr = CRED();
+	ssize_t ret;
+	struct inode *ip = in->f_mapping->host;
+	znode_t *zp = ITOZ(ip);
+	uint64_t file_sz;
+	struct iov_iter to;
+	uio_seg_t seg = UIO_USERSPACE;
+	struct iovec fiovec; // fake iovec
+
+	fiovec.iov_len = len;
+	fiovec.iov_base = kmalloc(len, GFP_KERNEL);
+	fstrans_cookie_t cookie;
+
+	spl_inode_lock_shared(ip);
+	cookie = spl_fstrans_mark();
+	//file_sz = zp->z_size;
+	//if ((*ppos+len) > file_sz) {
+	//	len = 10;
+	//}
+
+
+
+	//error = -zfs_holey(ip, SEEK_DATA, ppos);
+	spl_fstrans_unmark(cookie);
+	spl_inode_unlock_shared(ip);
+
+	ssize_t read = zpl_read_common(ip, fiovec.iov_base, len, ppos, seg, in->f_flags, cr);
+	ret = _copy_to_iter(fiovec.iov_base, len, &to);
+	printk(KERN_INFO "%s:%d(pipe,out,%llu,%lu,%x):%li\n", __func__, __LINE__,
+						*ppos,len,flags,(long int)read);
+	kfree(fiovec.iov_base);
+	return ret;
+}
+
 const struct file_operations zpl_file_operations = {
 	.open		= zpl_open,
 	.release	= zpl_release,
@@ -1012,6 +1071,8 @@ const struct file_operations zpl_file_operations = {
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= zpl_compat_ioctl,
 #endif
+	.splice_read    = zpl_file_splice_read,
+	.splice_write   = zpl_iter_file_splice_write,
 };
 
 const struct file_operations zpl_dir_file_operations = {

diff --git a/module/zcommon/zfs_uio.c b/module/zcommon/zfs_uio.c
@@ -77,8 +77,12 @@ uiomove_iov(void *p, size_t n, enum uio_rw rw, struct uio *uio)
 			 * iov->iov_base = user data pointer
 			 */
 			if (rw == UIO_READ) {
-				if (copy_to_user(iov->iov_base+skip, p, cnt))
+				unsigned long b_left = copy_to_user(iov->iov_base+skip, p, cnt);
+				if (b_left > 0) {
+					printk(KERN_INFO "%s:%d(skip:%zu,cnt:%lu,%llx,%llx):%lu\n", __func__, __LINE__, skip,cnt,(uint64_t)iov->iov_base,(uint64_t)p,b_left);
+					dump_stack();
 					return (EFAULT);
+				}
 			} else {
 				unsigned long b_left = 0;
 				if (uio->uio_fault_disable) {