xref: /linux/fs/nfs/nfs4file.c (revision 4413e16d9d21673bb5048a2e542f1aaa00015c2e)
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 "pnfs.h"
9 
10 #define NFSDBG_FACILITY		NFSDBG_FILE
11 
12 static int
13 nfs4_file_open(struct inode *inode, struct file *filp)
14 {
15 	struct nfs_open_context *ctx;
16 	struct dentry *dentry = filp->f_path.dentry;
17 	struct dentry *parent = NULL;
18 	struct inode *dir;
19 	unsigned openflags = filp->f_flags;
20 	struct iattr attr;
21 	int err;
22 
23 	BUG_ON(inode != dentry->d_inode);
24 	/*
25 	 * If no cached dentry exists or if it's negative, NFSv4 handled the
26 	 * opens in ->lookup() or ->create().
27 	 *
28 	 * We only get this far for a cached positive dentry.  We skipped
29 	 * revalidation, so handle it here by dropping the dentry and returning
30 	 * -EOPENSTALE.  The VFS will retry the lookup/create/open.
31 	 */
32 
33 	dprintk("NFS: open file(%s/%s)\n",
34 		dentry->d_parent->d_name.name,
35 		dentry->d_name.name);
36 
37 	if ((openflags & O_ACCMODE) == 3)
38 		openflags--;
39 
40 	/* We can't create new files here */
41 	openflags &= ~(O_CREAT|O_EXCL);
42 
43 	parent = dget_parent(dentry);
44 	dir = parent->d_inode;
45 
46 	ctx = alloc_nfs_open_context(filp->f_path.dentry, filp->f_mode);
47 	err = PTR_ERR(ctx);
48 	if (IS_ERR(ctx))
49 		goto out;
50 
51 	attr.ia_valid = ATTR_OPEN;
52 	if (openflags & O_TRUNC) {
53 		attr.ia_valid |= ATTR_SIZE;
54 		attr.ia_size = 0;
55 		nfs_wb_all(inode);
56 	}
57 
58 	inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr);
59 	if (IS_ERR(inode)) {
60 		err = PTR_ERR(inode);
61 		switch (err) {
62 		case -EPERM:
63 		case -EACCES:
64 		case -EDQUOT:
65 		case -ENOSPC:
66 		case -EROFS:
67 			goto out_put_ctx;
68 		default:
69 			goto out_drop;
70 		}
71 	}
72 	iput(inode);
73 	if (inode != dentry->d_inode)
74 		goto out_drop;
75 
76 	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
77 	nfs_file_set_open_context(filp, ctx);
78 	err = 0;
79 
80 out_put_ctx:
81 	put_nfs_open_context(ctx);
82 out:
83 	dput(parent);
84 	return err;
85 
86 out_drop:
87 	d_drop(dentry);
88 	err = -EOPENSTALE;
89 	goto out_put_ctx;
90 }
91 
92 static int
93 nfs4_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
94 {
95 	int ret;
96 	struct inode *inode = file->f_path.dentry->d_inode;
97 
98 	ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
99 	if (ret != 0)
100 		goto out;
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 out:
108 	return ret;
109 }
110 
111 const struct file_operations nfs4_file_operations = {
112 	.llseek		= nfs_file_llseek,
113 	.read		= do_sync_read,
114 	.write		= do_sync_write,
115 	.aio_read	= nfs_file_read,
116 	.aio_write	= nfs_file_write,
117 	.mmap		= nfs_file_mmap,
118 	.open		= nfs4_file_open,
119 	.flush		= nfs_file_flush,
120 	.release	= nfs_file_release,
121 	.fsync		= nfs4_file_fsync,
122 	.lock		= nfs_lock,
123 	.flock		= nfs_flock,
124 	.splice_read	= nfs_file_splice_read,
125 	.splice_write	= nfs_file_splice_write,
126 	.check_flags	= nfs_check_flags,
127 	.setlease	= nfs_setlease,
128 };
129