xref: /openbmc/linux/fs/nfs/nfs4file.c (revision e23feb16)
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 
13 static int
14 nfs4_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(%s/%s)\n",
35 		dentry->d_parent->d_name.name,
36 		dentry->d_name.name);
37 
38 	if ((openflags & O_ACCMODE) == 3)
39 		openflags--;
40 
41 	/* We can't create new files here */
42 	openflags &= ~(O_CREAT|O_EXCL);
43 
44 	parent = dget_parent(dentry);
45 	dir = parent->d_inode;
46 
47 	ctx = alloc_nfs_open_context(filp->f_path.dentry, filp->f_mode);
48 	err = PTR_ERR(ctx);
49 	if (IS_ERR(ctx))
50 		goto out;
51 
52 	attr.ia_valid = ATTR_OPEN;
53 	if (openflags & O_TRUNC) {
54 		attr.ia_valid |= ATTR_SIZE;
55 		attr.ia_size = 0;
56 		nfs_wb_all(inode);
57 	}
58 
59 	inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, &opened);
60 	if (IS_ERR(inode)) {
61 		err = PTR_ERR(inode);
62 		switch (err) {
63 		case -EPERM:
64 		case -EACCES:
65 		case -EDQUOT:
66 		case -ENOSPC:
67 		case -EROFS:
68 			goto out_put_ctx;
69 		default:
70 			goto out_drop;
71 		}
72 	}
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 	nfs_fscache_set_inode_cookie(inode, filp);
79 	err = 0;
80 
81 out_put_ctx:
82 	put_nfs_open_context(ctx);
83 out:
84 	dput(parent);
85 	return err;
86 
87 out_drop:
88 	d_drop(dentry);
89 	err = -EOPENSTALE;
90 	goto out_put_ctx;
91 }
92 
93 static int
94 nfs4_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
95 {
96 	int ret;
97 	struct inode *inode = file_inode(file);
98 
99 	do {
100 		ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
101 		if (ret != 0)
102 			break;
103 		mutex_lock(&inode->i_mutex);
104 		ret = nfs_file_fsync_commit(file, start, end, datasync);
105 		if (!ret && !datasync)
106 			/* application has asked for meta-data sync */
107 			ret = pnfs_layoutcommit_inode(inode, true);
108 		mutex_unlock(&inode->i_mutex);
109 		/*
110 		 * If nfs_file_fsync_commit detected a server reboot, then
111 		 * resend all dirty pages that might have been covered by
112 		 * the NFS_CONTEXT_RESEND_WRITES flag
113 		 */
114 		start = 0;
115 		end = LLONG_MAX;
116 	} while (ret == -EAGAIN);
117 
118 	return ret;
119 }
120 
121 const struct file_operations nfs4_file_operations = {
122 	.llseek		= nfs_file_llseek,
123 	.read		= do_sync_read,
124 	.write		= do_sync_write,
125 	.aio_read	= nfs_file_read,
126 	.aio_write	= nfs_file_write,
127 	.mmap		= nfs_file_mmap,
128 	.open		= nfs4_file_open,
129 	.flush		= nfs_file_flush,
130 	.release	= nfs_file_release,
131 	.fsync		= nfs4_file_fsync,
132 	.lock		= nfs_lock,
133 	.flock		= nfs_flock,
134 	.splice_read	= nfs_file_splice_read,
135 	.splice_write	= nfs_file_splice_write,
136 	.check_flags	= nfs_check_flags,
137 	.setlease	= nfs_setlease,
138 };
139