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1 | /* |
2 | * File operations for Coda. |
3 | * Original version: (C) 1996 Peter Braam |
4 | * Rewritten for Linux 2.1: (C) 1997 Carnegie Mellon University |
5 | * |
6 | * Carnegie Mellon encourages users of this code to contribute improvements |
7 | * to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>. |
8 | */ |
9 | |
10 | #include <linux/types.h> |
11 | #include <linux/kernel.h> |
12 | #include <linux/time.h> |
13 | #include <linux/file.h> |
14 | #include <linux/fs.h> |
15 | #include <linux/stat.h> |
16 | #include <linux/cred.h> |
17 | #include <linux/errno.h> |
18 | #include <linux/smp_lock.h> |
19 | #include <linux/string.h> |
20 | #include <linux/slab.h> |
21 | #include <asm/uaccess.h> |
22 | |
23 | #include <linux/coda.h> |
24 | #include <linux/coda_linux.h> |
25 | #include <linux/coda_fs_i.h> |
26 | #include <linux/coda_psdev.h> |
27 | |
28 | #include "coda_int.h" |
29 | |
30 | static ssize_t |
31 | coda_file_read(struct file *coda_file, char __user *buf, size_t count, loff_t *ppos) |
32 | { |
33 | struct coda_file_info *cfi; |
34 | struct file *host_file; |
35 | |
36 | cfi = CODA_FTOC(coda_file); |
37 | BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); |
38 | host_file = cfi->cfi_container; |
39 | |
40 | if (!host_file->f_op || !host_file->f_op->read) |
41 | return -EINVAL; |
42 | |
43 | return host_file->f_op->read(host_file, buf, count, ppos); |
44 | } |
45 | |
46 | static ssize_t |
47 | coda_file_splice_read(struct file *coda_file, loff_t *ppos, |
48 | struct pipe_inode_info *pipe, size_t count, |
49 | unsigned int flags) |
50 | { |
51 | ssize_t (*splice_read)(struct file *, loff_t *, |
52 | struct pipe_inode_info *, size_t, unsigned int); |
53 | struct coda_file_info *cfi; |
54 | struct file *host_file; |
55 | |
56 | cfi = CODA_FTOC(coda_file); |
57 | BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); |
58 | host_file = cfi->cfi_container; |
59 | |
60 | splice_read = host_file->f_op->splice_read; |
61 | if (!splice_read) |
62 | splice_read = default_file_splice_read; |
63 | |
64 | return splice_read(host_file, ppos, pipe, count, flags); |
65 | } |
66 | |
67 | static ssize_t |
68 | coda_file_write(struct file *coda_file, const char __user *buf, size_t count, loff_t *ppos) |
69 | { |
70 | struct inode *host_inode, *coda_inode = coda_file->f_path.dentry->d_inode; |
71 | struct coda_file_info *cfi; |
72 | struct file *host_file; |
73 | ssize_t ret; |
74 | |
75 | cfi = CODA_FTOC(coda_file); |
76 | BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); |
77 | host_file = cfi->cfi_container; |
78 | |
79 | if (!host_file->f_op || !host_file->f_op->write) |
80 | return -EINVAL; |
81 | |
82 | host_inode = host_file->f_path.dentry->d_inode; |
83 | mutex_lock(&coda_inode->i_mutex); |
84 | |
85 | ret = host_file->f_op->write(host_file, buf, count, ppos); |
86 | |
87 | coda_inode->i_size = host_inode->i_size; |
88 | coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9; |
89 | coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC; |
90 | mutex_unlock(&coda_inode->i_mutex); |
91 | |
92 | return ret; |
93 | } |
94 | |
95 | static int |
96 | coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma) |
97 | { |
98 | struct coda_file_info *cfi; |
99 | struct coda_inode_info *cii; |
100 | struct file *host_file; |
101 | struct inode *coda_inode, *host_inode; |
102 | |
103 | cfi = CODA_FTOC(coda_file); |
104 | BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); |
105 | host_file = cfi->cfi_container; |
106 | |
107 | if (!host_file->f_op || !host_file->f_op->mmap) |
108 | return -ENODEV; |
109 | |
110 | coda_inode = coda_file->f_path.dentry->d_inode; |
111 | host_inode = host_file->f_path.dentry->d_inode; |
112 | coda_file->f_mapping = host_file->f_mapping; |
113 | if (coda_inode->i_mapping == &coda_inode->i_data) |
114 | coda_inode->i_mapping = host_inode->i_mapping; |
115 | |
116 | /* only allow additional mmaps as long as userspace isn't changing |
117 | * the container file on us! */ |
118 | else if (coda_inode->i_mapping != host_inode->i_mapping) |
119 | return -EBUSY; |
120 | |
121 | /* keep track of how often the coda_inode/host_file has been mmapped */ |
122 | cii = ITOC(coda_inode); |
123 | cii->c_mapcount++; |
124 | cfi->cfi_mapcount++; |
125 | |
126 | return host_file->f_op->mmap(host_file, vma); |
127 | } |
128 | |
129 | int coda_open(struct inode *coda_inode, struct file *coda_file) |
130 | { |
131 | struct file *host_file = NULL; |
132 | int error; |
133 | unsigned short flags = coda_file->f_flags & (~O_EXCL); |
134 | unsigned short coda_flags = coda_flags_to_cflags(flags); |
135 | struct coda_file_info *cfi; |
136 | |
137 | cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL); |
138 | if (!cfi) |
139 | return -ENOMEM; |
140 | |
141 | lock_kernel(); |
142 | |
143 | error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags, |
144 | &host_file); |
145 | if (!host_file) |
146 | error = -EIO; |
147 | |
148 | if (error) { |
149 | kfree(cfi); |
150 | unlock_kernel(); |
151 | return error; |
152 | } |
153 | |
154 | host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC); |
155 | |
156 | cfi->cfi_magic = CODA_MAGIC; |
157 | cfi->cfi_mapcount = 0; |
158 | cfi->cfi_container = host_file; |
159 | |
160 | BUG_ON(coda_file->private_data != NULL); |
161 | coda_file->private_data = cfi; |
162 | |
163 | unlock_kernel(); |
164 | return 0; |
165 | } |
166 | |
167 | int coda_release(struct inode *coda_inode, struct file *coda_file) |
168 | { |
169 | unsigned short flags = (coda_file->f_flags) & (~O_EXCL); |
170 | unsigned short coda_flags = coda_flags_to_cflags(flags); |
171 | struct coda_file_info *cfi; |
172 | struct coda_inode_info *cii; |
173 | struct inode *host_inode; |
174 | int err = 0; |
175 | |
176 | lock_kernel(); |
177 | |
178 | cfi = CODA_FTOC(coda_file); |
179 | BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); |
180 | |
181 | err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode), |
182 | coda_flags, coda_file->f_cred->fsuid); |
183 | |
184 | host_inode = cfi->cfi_container->f_path.dentry->d_inode; |
185 | cii = ITOC(coda_inode); |
186 | |
187 | /* did we mmap this file? */ |
188 | if (coda_inode->i_mapping == &host_inode->i_data) { |
189 | cii->c_mapcount -= cfi->cfi_mapcount; |
190 | if (!cii->c_mapcount) |
191 | coda_inode->i_mapping = &coda_inode->i_data; |
192 | } |
193 | |
194 | fput(cfi->cfi_container); |
195 | kfree(coda_file->private_data); |
196 | coda_file->private_data = NULL; |
197 | |
198 | unlock_kernel(); |
199 | |
200 | /* VFS fput ignores the return value from file_operations->release, so |
201 | * there is no use returning an error here */ |
202 | return 0; |
203 | } |
204 | |
205 | int coda_fsync(struct file *coda_file, struct dentry *coda_dentry, int datasync) |
206 | { |
207 | struct file *host_file; |
208 | struct inode *coda_inode = coda_dentry->d_inode; |
209 | struct coda_file_info *cfi; |
210 | int err = 0; |
211 | |
212 | if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) || |
213 | S_ISLNK(coda_inode->i_mode))) |
214 | return -EINVAL; |
215 | |
216 | cfi = CODA_FTOC(coda_file); |
217 | BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC); |
218 | host_file = cfi->cfi_container; |
219 | |
220 | err = vfs_fsync(host_file, host_file->f_path.dentry, datasync); |
221 | if ( !err && !datasync ) { |
222 | lock_kernel(); |
223 | err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode)); |
224 | unlock_kernel(); |
225 | } |
226 | |
227 | return err; |
228 | } |
229 | |
230 | const struct file_operations coda_file_operations = { |
231 | .llseek = generic_file_llseek, |
232 | .read = coda_file_read, |
233 | .write = coda_file_write, |
234 | .mmap = coda_file_mmap, |
235 | .open = coda_open, |
236 | .release = coda_release, |
237 | .fsync = coda_fsync, |
238 | .splice_read = coda_file_splice_read, |
239 | }; |
240 | |
241 |
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