2 * File operations for Coda.
3 * Original version: (C) 1996 Peter Braam
4 * Rewritten for Linux 2.1: (C) 1997 Carnegie Mellon University
6 * Carnegie Mellon encourages users of this code to contribute improvements
7 * to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>.
10 #include <linux/types.h>
11 #include <linux/kernel.h>
12 #include <linux/time.h>
13 #include <linux/file.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 <asm/uaccess.h>
22 #include <linux/coda.h>
23 #include <linux/coda_linux.h>
24 #include <linux/coda_fs_i.h>
25 #include <linux/coda_psdev.h>
30 coda_file_read(struct file *coda_file, char __user *buf, size_t count, loff_t *ppos)
32 struct coda_file_info *cfi;
33 struct file *host_file;
35 cfi = CODA_FTOC(coda_file);
36 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
37 host_file = cfi->cfi_container;
39 if (!host_file->f_op || !host_file->f_op->read)
42 return host_file->f_op->read(host_file, buf, count, ppos);
46 coda_file_splice_read(struct file *coda_file, loff_t *ppos,
47 struct pipe_inode_info *pipe, size_t count,
50 ssize_t (*splice_read)(struct file *, loff_t *,
51 struct pipe_inode_info *, size_t, unsigned int);
52 struct coda_file_info *cfi;
53 struct file *host_file;
55 cfi = CODA_FTOC(coda_file);
56 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
57 host_file = cfi->cfi_container;
59 splice_read = host_file->f_op->splice_read;
61 splice_read = default_file_splice_read;
63 return splice_read(host_file, ppos, pipe, count, flags);
67 coda_file_write(struct file *coda_file, const char __user *buf, size_t count, loff_t *ppos)
69 struct inode *host_inode, *coda_inode = coda_file->f_path.dentry->d_inode;
70 struct coda_file_info *cfi;
71 struct file *host_file;
74 cfi = CODA_FTOC(coda_file);
75 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
76 host_file = cfi->cfi_container;
78 if (!host_file->f_op || !host_file->f_op->write)
81 host_inode = host_file->f_path.dentry->d_inode;
82 mutex_lock(&coda_inode->i_mutex);
84 ret = host_file->f_op->write(host_file, buf, count, ppos);
86 coda_inode->i_size = host_inode->i_size;
87 coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
88 coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC;
89 mutex_unlock(&coda_inode->i_mutex);
95 coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
97 struct coda_file_info *cfi;
98 struct coda_inode_info *cii;
99 struct file *host_file;
100 struct inode *coda_inode, *host_inode;
102 cfi = CODA_FTOC(coda_file);
103 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
104 host_file = cfi->cfi_container;
106 if (!host_file->f_op || !host_file->f_op->mmap)
109 coda_inode = coda_file->f_path.dentry->d_inode;
110 host_inode = host_file->f_path.dentry->d_inode;
111 coda_file->f_mapping = host_file->f_mapping;
112 if (coda_inode->i_mapping == &coda_inode->i_data)
113 coda_inode->i_mapping = host_inode->i_mapping;
115 /* only allow additional mmaps as long as userspace isn't changing
116 * the container file on us! */
117 else if (coda_inode->i_mapping != host_inode->i_mapping)
120 /* keep track of how often the coda_inode/host_file has been mmapped */
121 cii = ITOC(coda_inode);
125 return host_file->f_op->mmap(host_file, vma);
128 int coda_open(struct inode *coda_inode, struct file *coda_file)
130 struct file *host_file = NULL;
132 unsigned short flags = coda_file->f_flags & (~O_EXCL);
133 unsigned short coda_flags = coda_flags_to_cflags(flags);
134 struct coda_file_info *cfi;
136 cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
142 error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
153 host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC);
155 cfi->cfi_magic = CODA_MAGIC;
156 cfi->cfi_mapcount = 0;
157 cfi->cfi_container = host_file;
159 BUG_ON(coda_file->private_data != NULL);
160 coda_file->private_data = cfi;
166 int coda_release(struct inode *coda_inode, struct file *coda_file)
168 unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
169 unsigned short coda_flags = coda_flags_to_cflags(flags);
170 struct coda_file_info *cfi;
171 struct coda_inode_info *cii;
172 struct inode *host_inode;
177 cfi = CODA_FTOC(coda_file);
178 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
180 err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
181 coda_flags, coda_file->f_cred->fsuid);
183 host_inode = cfi->cfi_container->f_path.dentry->d_inode;
184 cii = ITOC(coda_inode);
186 /* did we mmap this file? */
187 if (coda_inode->i_mapping == &host_inode->i_data) {
188 cii->c_mapcount -= cfi->cfi_mapcount;
189 if (!cii->c_mapcount)
190 coda_inode->i_mapping = &coda_inode->i_data;
193 fput(cfi->cfi_container);
194 kfree(coda_file->private_data);
195 coda_file->private_data = NULL;
199 /* VFS fput ignores the return value from file_operations->release, so
200 * there is no use returning an error here */
204 int coda_fsync(struct file *coda_file, struct dentry *coda_dentry, int datasync)
206 struct file *host_file;
207 struct inode *coda_inode = coda_dentry->d_inode;
208 struct coda_file_info *cfi;
211 if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) ||
212 S_ISLNK(coda_inode->i_mode)))
215 cfi = CODA_FTOC(coda_file);
216 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
217 host_file = cfi->cfi_container;
219 err = vfs_fsync(host_file, host_file->f_path.dentry, datasync);
220 if ( !err && !datasync ) {
222 err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
229 const struct file_operations coda_file_operations = {
230 .llseek = generic_file_llseek,
231 .read = coda_file_read,
232 .write = coda_file_write,
233 .mmap = coda_file_mmap,
235 .release = coda_release,
237 .splice_read = coda_file_splice_read,