1/*
  2 *  linux/fs/nfs/file.c
  3 *
  4 *  Copyright (C) 1992  Rick Sladkey
  5 */
  6#include <linux/nfs_fs.h>
  7#include "internal.h"
  8#include "fscache.h"
  9#include "pnfs.h"
 10
 11#define NFSDBG_FACILITY		NFSDBG_FILE
 12
 13static int
 14nfs4_file_open(struct inode *inode, struct file *filp)
 15{
 16	struct nfs_open_context *ctx;
 17	struct dentry *dentry = filp->f_path.dentry;
 18	struct dentry *parent = NULL;
 19	struct inode *dir;
 20	unsigned openflags = filp->f_flags;
 21	struct iattr attr;
 22	int opened = 0;
 23	int err;
 24
 25	/*
 26	 * If no cached dentry exists or if it's negative, NFSv4 handled the
 27	 * opens in ->lookup() or ->create().
 28	 *
 29	 * We only get this far for a cached positive dentry.  We skipped
 30	 * revalidation, so handle it here by dropping the dentry and returning
 31	 * -EOPENSTALE.  The VFS will retry the lookup/create/open.
 32	 */
 33
 34	dprintk("NFS: open file(%pd2)\n", dentry);
 35
 36	if ((openflags & O_ACCMODE) == 3)
 37		openflags--;
 38
 39	/* We can't create new files here */
 40	openflags &= ~(O_CREAT|O_EXCL);
 41
 42	parent = dget_parent(dentry);
 43	dir = parent->d_inode;
 44
 45	ctx = alloc_nfs_open_context(filp->f_path.dentry, filp->f_mode);
 46	err = PTR_ERR(ctx);
 47	if (IS_ERR(ctx))
 48		goto out;
 49
 50	attr.ia_valid = ATTR_OPEN;
 51	if (openflags & O_TRUNC) {
 52		attr.ia_valid |= ATTR_SIZE;
 53		attr.ia_size = 0;
 54		nfs_wb_all(inode);
 55	}
 56
 57	inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, &opened);
 58	if (IS_ERR(inode)) {
 59		err = PTR_ERR(inode);
 60		switch (err) {
 61		case -EPERM:
 62		case -EACCES:
 63		case -EDQUOT:
 64		case -ENOSPC:
 65		case -EROFS:
 66			goto out_put_ctx;
 67		default:
 68			goto out_drop;
 69		}
 70	}
 71	if (inode != dentry->d_inode)
 72		goto out_drop;
 73
 74	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
 75	nfs_file_set_open_context(filp, ctx);
 76	nfs_fscache_open_file(inode, filp);
 77	err = 0;
 78
 79out_put_ctx:
 80	put_nfs_open_context(ctx);
 81out:
 82	dput(parent);
 83	return err;
 84
 85out_drop:
 86	d_drop(dentry);
 87	err = -EOPENSTALE;
 88	goto out_put_ctx;
 89}
 90
 91static int
 92nfs4_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 93{
 94	int ret;
 95	struct inode *inode = file_inode(file);
 96
 97	do {
 98		ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
 99		if (ret != 0)
100			break;
101		mutex_lock(&inode->i_mutex);
102		ret = nfs_file_fsync_commit(file, start, end, datasync);
103		if (!ret && !datasync)
104			/* application has asked for meta-data sync */
105			ret = pnfs_layoutcommit_inode(inode, true);
106		mutex_unlock(&inode->i_mutex);
107		/*
108		 * If nfs_file_fsync_commit detected a server reboot, then
109		 * resend all dirty pages that might have been covered by
110		 * the NFS_CONTEXT_RESEND_WRITES flag
111		 */
112		start = 0;
113		end = LLONG_MAX;
114	} while (ret == -EAGAIN);
115
116	return ret;
117}
118
119const struct file_operations nfs4_file_operations = {
120	.llseek		= nfs_file_llseek,
121	.read		= do_sync_read,
122	.write		= do_sync_write,
123	.aio_read	= nfs_file_read,
124	.aio_write	= nfs_file_write,
125	.mmap		= nfs_file_mmap,
126	.open		= nfs4_file_open,
127	.flush		= nfs_file_flush,
128	.release	= nfs_file_release,
129	.fsync		= nfs4_file_fsync,
130	.lock		= nfs_lock,
131	.flock		= nfs_flock,
132	.splice_read	= nfs_file_splice_read,
133	.splice_write	= nfs_file_splice_write,
134	.check_flags	= nfs_check_flags,
135	.setlease	= nfs_setlease,
136};