xref: /openbmc/linux/fs/nfs/nfs4file.c (revision 0d456bad)
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 	/*
24 	 * If no cached dentry exists or if it's negative, NFSv4 handled the
25 	 * opens in ->lookup() or ->create().
26 	 *
27 	 * We only get this far for a cached positive dentry.  We skipped
28 	 * revalidation, so handle it here by dropping the dentry and returning
29 	 * -EOPENSTALE.  The VFS will retry the lookup/create/open.
30 	 */
31 
32 	dprintk("NFS: open file(%s/%s)\n",
33 		dentry->d_parent->d_name.name,
34 		dentry->d_name.name);
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);
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 	iput(inode);
72 	if (inode != dentry->d_inode)
73 		goto out_drop;
74 
75 	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
76 	nfs_file_set_open_context(filp, ctx);
77 	err = 0;
78 
79 out_put_ctx:
80 	put_nfs_open_context(ctx);
81 out:
82 	dput(parent);
83 	return err;
84 
85 out_drop:
86 	d_drop(dentry);
87 	err = -EOPENSTALE;
88 	goto out_put_ctx;
89 }
90 
91 static int
92 nfs4_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
93 {
94 	int ret;
95 	struct inode *inode = file->f_path.dentry->d_inode;
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 
119 const 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 };
137