1 files changed, 350 insertions, 0 deletions
diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
new file mode 100644
index 000000000000..c5e884585c23
--- /dev/null
+++ b/fs/nfs/nfs4file.c
@@ -0,0 +1,350 @@
+/*
+ *  linux/fs/nfs/file.c
+ *
+ *  Copyright (C) 1992  Rick Sladkey
+ */
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/falloc.h>
+#include <linux/nfs_fs.h>
+#include <uapi/linux/btrfs.h>	/* BTRFS_IOC_CLONE/BTRFS_IOC_CLONE_RANGE */
+#include "delegation.h"
+#include "internal.h"
+#include "iostat.h"
+#include "fscache.h"
+#include "pnfs.h"
+
+#include "nfstrace.h"
+
+#ifdef CONFIG_NFS_V4_2
+#include "nfs42.h"
+#endif
+
+#define NFSDBG_FACILITY		NFSDBG_FILE
+
+static int
+nfs4_file_open(struct inode *inode, struct file *filp)
+{
+	struct nfs_open_context *ctx;
+	struct dentry *dentry = file_dentry(filp);
+	struct dentry *parent = NULL;
+	struct inode *dir;
+	unsigned openflags = filp->f_flags;
+	struct iattr attr;
+	int err;
+
+	/*
+	 * If no cached dentry exists or if it's negative, NFSv4 handled the
+	 * opens in ->lookup() or ->create().
+	 *
+	 * We only get this far for a cached positive dentry.  We skipped
+	 * revalidation, so handle it here by dropping the dentry and returning
+	 * -EOPENSTALE.  The VFS will retry the lookup/create/open.
+	 */
+
+	dprintk("NFS: open file(%pd2)\n", dentry);
+
+	err = nfs_check_flags(openflags);
+	if (err)
+		return err;
+
+	if ((openflags & O_ACCMODE) == 3)
+		return nfs_open(inode, filp);
+
+	/* We can't create new files here */
+	openflags &= ~(O_CREAT|O_EXCL);
+
+	parent = dget_parent(dentry);
+	dir = d_inode(parent);
+
+	ctx = alloc_nfs_open_context(file_dentry(filp), filp->f_mode);
+	err = PTR_ERR(ctx);
+	if (IS_ERR(ctx))
+		goto out;
+
+	attr.ia_valid = ATTR_OPEN;
+	if (openflags & O_TRUNC) {
+		attr.ia_valid |= ATTR_SIZE;
+		attr.ia_size = 0;
+		nfs_sync_inode(inode);
+	}
+
+	inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, NULL);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		switch (err) {
+		default:
+			goto out_put_ctx;
+		case -ENOENT:
+		case -ESTALE:
+		case -EISDIR:
+		case -ENOTDIR:
+		case -ELOOP:
+			goto out_drop;
+		}
+	}
+	if (inode != d_inode(dentry))
+		goto out_drop;
+
+	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+	nfs_file_set_open_context(filp, ctx);
+	nfs_fscache_open_file(inode, filp);
+	err = 0;
+
+out_put_ctx:
+	put_nfs_open_context(ctx);
+out:
+	dput(parent);
+	return err;
+
+out_drop:
+	d_drop(dentry);
+	err = -EOPENSTALE;
+	goto out_put_ctx;
+}
+
+/*
+ * Flush all dirty pages, and check for write errors.
+ */
+static int
+nfs4_file_flush(struct file *file, fl_owner_t id)
+{
+	struct inode	*inode = file_inode(file);
+
+	dprintk("NFS: flush(%pD2)\n", file);
+
+	nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
+	if ((file->f_mode & FMODE_WRITE) == 0)
+		return 0;
+
+	/*
+	 * If we're holding a write delegation, then check if we're required
+	 * to flush the i/o on close. If not, then just start the i/o now.
+	 */
+	if (!nfs4_delegation_flush_on_close(inode))
+		return filemap_fdatawrite(file->f_mapping);
+
+	/* Flush writes to the server and return any errors */
+	return vfs_fsync(file, 0);
+}
+
+static int
+nfs4_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
+{
+	int ret;
+	struct inode *inode = file_inode(file);
+
+	trace_nfs_fsync_enter(inode);
+
+	nfs_inode_dio_wait(inode);
+	do {
+		ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
+		if (ret != 0)
+			break;
+		mutex_lock(&inode->i_mutex);
+		ret = nfs_file_fsync_commit(file, start, end, datasync);
+		if (!ret)
+			ret = pnfs_sync_inode(inode, !!datasync);
+		mutex_unlock(&inode->i_mutex);
+		/*
+		 * If nfs_file_fsync_commit detected a server reboot, then
+		 * resend all dirty pages that might have been covered by
+		 * the NFS_CONTEXT_RESEND_WRITES flag
+		 */
+		start = 0;
+		end = LLONG_MAX;
+	} while (ret == -EAGAIN);
+
+	trace_nfs_fsync_exit(inode, ret);
+	return ret;
+}
+
+#ifdef CONFIG_NFS_V4_2
+static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
+{
+	loff_t ret;
+
+	switch (whence) {
+	case SEEK_HOLE:
+	case SEEK_DATA:
+		ret = nfs42_proc_llseek(filep, offset, whence);
+		if (ret != -ENOTSUPP)
+			return ret;
+	default:
+		return nfs_file_llseek(filep, offset, whence);
+	}
+}
+
+static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
+{
+	struct inode *inode = file_inode(filep);
+	long ret;
+
+	if (!S_ISREG(inode->i_mode))
+		return -EOPNOTSUPP;
+
+	if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
+		return -EOPNOTSUPP;
+
+	ret = inode_newsize_ok(inode, offset + len);
+	if (ret < 0)
+		return ret;
+
+	if (mode & FALLOC_FL_PUNCH_HOLE)
+		return nfs42_proc_deallocate(filep, offset, len);
+	return nfs42_proc_allocate(filep, offset, len);
+}
+
+static noinline long
+nfs42_ioctl_clone(struct file *dst_file, unsigned long srcfd,
+		  u64 src_off, u64 dst_off, u64 count)
+{
+	struct inode *dst_inode = file_inode(dst_file);
+	struct nfs_server *server = NFS_SERVER(dst_inode);
+	struct fd src_file;
+	struct inode *src_inode;
+	unsigned int bs = server->clone_blksize;
+	bool same_inode = false;
+	int ret;
+
+	/* dst file must be opened for writing */
+	if (!(dst_file->f_mode & FMODE_WRITE))
+		return -EINVAL;
+
+	ret = mnt_want_write_file(dst_file);
+	if (ret)
+		return ret;
+
+	src_file = fdget(srcfd);
+	if (!src_file.file) {
+		ret = -EBADF;
+		goto out_drop_write;
+	}
+
+	src_inode = file_inode(src_file.file);
+
+	if (src_inode == dst_inode)
+		same_inode = true;
+
+	/* src file must be opened for reading */
+	if (!(src_file.file->f_mode & FMODE_READ))
+		goto out_fput;
+
+	/* src and dst must be regular files */
+	ret = -EISDIR;
+	if (!S_ISREG(src_inode->i_mode) || !S_ISREG(dst_inode->i_mode))
+		goto out_fput;
+
+	ret = -EXDEV;
+	if (src_file.file->f_path.mnt != dst_file->f_path.mnt ||
+	    src_inode->i_sb != dst_inode->i_sb)
+		goto out_fput;
+
+	/* check alignment w.r.t. clone_blksize */
+	ret = -EINVAL;
+	if (bs) {
+		if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
+			goto out_fput;
+		if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
+			goto out_fput;
+	}
+
+	/* verify if ranges are overlapped within the same file */
+	if (same_inode) {
+		if (dst_off + count > src_off && dst_off < src_off + count)
+			goto out_fput;
+	}
+
+	/* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
+	if (same_inode) {
+		mutex_lock(&src_inode->i_mutex);
+	} else if (dst_inode < src_inode) {
+		mutex_lock_nested(&dst_inode->i_mutex, I_MUTEX_PARENT);
+		mutex_lock_nested(&src_inode->i_mutex, I_MUTEX_CHILD);
+	} else {
+		mutex_lock_nested(&src_inode->i_mutex, I_MUTEX_PARENT);
+		mutex_lock_nested(&dst_inode->i_mutex, I_MUTEX_CHILD);
+	}
+
+	/* flush all pending writes on both src and dst so that server
+	 * has the latest data */
+	ret = nfs_sync_inode(src_inode);
+	if (ret)
+		goto out_unlock;
+	ret = nfs_sync_inode(dst_inode);
+	if (ret)
+		goto out_unlock;
+
+	ret = nfs42_proc_clone(src_file.file, dst_file, src_off, dst_off, count);
+
+	/* truncate inode page cache of the dst range so that future reads can fetch
+	 * new data from server */
+	if (!ret)
+		truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
+
+out_unlock:
+	if (same_inode) {
+		mutex_unlock(&src_inode->i_mutex);
+	} else if (dst_inode < src_inode) {
+		mutex_unlock(&src_inode->i_mutex);
+		mutex_unlock(&dst_inode->i_mutex);
+	} else {
+		mutex_unlock(&dst_inode->i_mutex);
+		mutex_unlock(&src_inode->i_mutex);
+	}
+out_fput:
+	fdput(src_file);
+out_drop_write:
+	mnt_drop_write_file(dst_file);
+	return ret;
+}
+
+static long nfs42_ioctl_clone_range(struct file *dst_file, void __user *argp)
+{
+	struct btrfs_ioctl_clone_range_args args;
+
+	if (copy_from_user(&args, argp, sizeof(args)))
+		return -EFAULT;
+
+	return nfs42_ioctl_clone(dst_file, args.src_fd, args.src_offset,
+				 args.dest_offset, args.src_length);
+}
+
+long nfs4_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	void __user *argp = (void __user *)arg;
+
+	switch (cmd) {
+	case BTRFS_IOC_CLONE:
+		return nfs42_ioctl_clone(file, arg, 0, 0, 0);
+	case BTRFS_IOC_CLONE_RANGE:
+		return nfs42_ioctl_clone_range(file, argp);
+	}
+
+	return -ENOTTY;
+}
+#endif /* CONFIG_NFS_V4_2 */
+
+const struct file_operations nfs4_file_operations = {
+	.read_iter	= nfs_file_read,
+	.write_iter	= nfs_file_write,
+	.mmap		= nfs_file_mmap,
+	.open		= nfs4_file_open,
+	.flush		= nfs4_file_flush,
+	.release	= nfs_file_release,
+	.fsync		= nfs4_file_fsync,
+	.lock		= nfs_lock,
+	.flock		= nfs_flock,
+	.splice_read	= nfs_file_splice_read,
+	.splice_write	= iter_file_splice_write,
+	.check_flags	= nfs_check_flags,
+	.setlease	= simple_nosetlease,
+#ifdef CONFIG_NFS_V4_2
+	.llseek		= nfs4_file_llseek,
+	.fallocate	= nfs42_fallocate,
+	.unlocked_ioctl = nfs4_ioctl,
+	.compat_ioctl	= nfs4_ioctl,
+#else
+	.llseek		= nfs_file_llseek,
+#endif
+};