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/spinlock.h>
20 #include <linux/string.h>
21 #include <linux/slab.h>
22 #include <asm/uaccess.h>
24 #include <linux/coda.h>
25 #include <linux/coda_linux.h>
26 #include <linux/coda_fs_i.h>
27 #include <linux/coda_psdev.h>
32 coda_file_read(struct file *coda_file, char __user *buf, size_t count, loff_t *ppos)
34 struct coda_file_info *cfi;
35 struct file *host_file;
37 cfi = CODA_FTOC(coda_file);
38 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
39 host_file = cfi->cfi_container;
41 if (!host_file->f_op || !host_file->f_op->read)
44 return host_file->f_op->read(host_file, buf, count, ppos);
48 coda_file_splice_read(struct file *coda_file, loff_t *ppos,
49 struct pipe_inode_info *pipe, size_t count,
52 ssize_t (*splice_read)(struct file *, loff_t *,
53 struct pipe_inode_info *, size_t, unsigned int);
54 struct coda_file_info *cfi;
55 struct file *host_file;
57 cfi = CODA_FTOC(coda_file);
58 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
59 host_file = cfi->cfi_container;
61 splice_read = host_file->f_op->splice_read;
63 splice_read = default_file_splice_read;
65 return splice_read(host_file, ppos, pipe, count, flags);
69 coda_file_write(struct file *coda_file, const char __user *buf, size_t count, loff_t *ppos)
71 struct inode *host_inode, *coda_inode = coda_file->f_path.dentry->d_inode;
72 struct coda_file_info *cfi;
73 struct file *host_file;
76 cfi = CODA_FTOC(coda_file);
77 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
78 host_file = cfi->cfi_container;
80 if (!host_file->f_op || !host_file->f_op->write)
83 host_inode = host_file->f_path.dentry->d_inode;
84 mutex_lock(&coda_inode->i_mutex);
86 ret = host_file->f_op->write(host_file, buf, count, ppos);
88 coda_inode->i_size = host_inode->i_size;
89 coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
90 coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC;
91 mutex_unlock(&coda_inode->i_mutex);
97 coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
99 struct coda_file_info *cfi;
100 struct coda_inode_info *cii;
101 struct file *host_file;
102 struct inode *coda_inode, *host_inode;
104 cfi = CODA_FTOC(coda_file);
105 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
106 host_file = cfi->cfi_container;
108 if (!host_file->f_op || !host_file->f_op->mmap)
111 coda_inode = coda_file->f_path.dentry->d_inode;
112 host_inode = host_file->f_path.dentry->d_inode;
114 cii = ITOC(coda_inode);
115 spin_lock(&cii->c_lock);
116 coda_file->f_mapping = host_file->f_mapping;
117 if (coda_inode->i_mapping == &coda_inode->i_data)
118 coda_inode->i_mapping = host_inode->i_mapping;
120 /* only allow additional mmaps as long as userspace isn't changing
121 * the container file on us! */
122 else if (coda_inode->i_mapping != host_inode->i_mapping) {
123 spin_unlock(&cii->c_lock);
127 /* keep track of how often the coda_inode/host_file has been mmapped */
130 spin_unlock(&cii->c_lock);
132 return host_file->f_op->mmap(host_file, vma);
135 int coda_open(struct inode *coda_inode, struct file *coda_file)
137 struct file *host_file = NULL;
139 unsigned short flags = coda_file->f_flags & (~O_EXCL);
140 unsigned short coda_flags = coda_flags_to_cflags(flags);
141 struct coda_file_info *cfi;
143 cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
149 error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
160 host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC);
162 cfi->cfi_magic = CODA_MAGIC;
163 cfi->cfi_mapcount = 0;
164 cfi->cfi_container = host_file;
166 BUG_ON(coda_file->private_data != NULL);
167 coda_file->private_data = cfi;
173 int coda_release(struct inode *coda_inode, struct file *coda_file)
175 unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
176 unsigned short coda_flags = coda_flags_to_cflags(flags);
177 struct coda_file_info *cfi;
178 struct coda_inode_info *cii;
179 struct inode *host_inode;
184 cfi = CODA_FTOC(coda_file);
185 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
187 err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
188 coda_flags, coda_file->f_cred->fsuid);
190 host_inode = cfi->cfi_container->f_path.dentry->d_inode;
191 cii = ITOC(coda_inode);
193 /* did we mmap this file? */
194 spin_lock(&cii->c_lock);
195 if (coda_inode->i_mapping == &host_inode->i_data) {
196 cii->c_mapcount -= cfi->cfi_mapcount;
197 if (!cii->c_mapcount)
198 coda_inode->i_mapping = &coda_inode->i_data;
200 spin_unlock(&cii->c_lock);
202 fput(cfi->cfi_container);
203 kfree(coda_file->private_data);
204 coda_file->private_data = NULL;
208 /* VFS fput ignores the return value from file_operations->release, so
209 * there is no use returning an error here */
213 int coda_fsync(struct file *coda_file, int datasync)
215 struct file *host_file;
216 struct inode *coda_inode = coda_file->f_path.dentry->d_inode;
217 struct coda_file_info *cfi;
220 if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) ||
221 S_ISLNK(coda_inode->i_mode)))
224 cfi = CODA_FTOC(coda_file);
225 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
226 host_file = cfi->cfi_container;
228 err = vfs_fsync(host_file, datasync);
229 if ( !err && !datasync ) {
231 err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
238 const struct file_operations coda_file_operations = {
239 .llseek = generic_file_llseek,
240 .read = coda_file_read,
241 .write = coda_file_write,
242 .mmap = coda_file_mmap,
244 .release = coda_release,
246 .splice_read = coda_file_splice_read,