[linux.git] / fs / coda / file.c

/*
 * File operations for Coda.
 * Original version: (C) 1996 Peter Braam 
 * Rewritten for Linux 2.1: (C) 1997 Carnegie Mellon University
 *
 * Carnegie Mellon encourages users of this code to contribute improvements
 * to the Coda project. Contact Peter Braam <[email protected]>.
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/time.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/stat.h>
#include <linux/errno.h>
#include <linux/smp_lock.h>
#include <linux/string.h>
#include <asm/uaccess.h>

#include <linux/coda.h>
#include <linux/coda_linux.h>
#include <linux/coda_fs_i.h>
#include <linux/coda_psdev.h>
#include <linux/coda_proc.h>

/* if CODA_STORE fails with EOPNOTSUPP, venus clearly doesn't support
 * CODA_STORE/CODA_RELEASE and we fall back on using the CODA_CLOSE upcall */
static int use_coda_close;

static ssize_t
coda_file_read(struct file *coda_file, char __user *buf, size_t count, loff_t *ppos)
{
	struct coda_file_info *cfi;
	struct file *host_file;

	cfi = CODA_FTOC(coda_file);
	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
	host_file = cfi->cfi_container;

	if (!host_file->f_op || !host_file->f_op->read)
		return -EINVAL;

	return host_file->f_op->read(host_file, buf, count, ppos);
}

static ssize_t
coda_file_sendfile(struct file *coda_file, loff_t *ppos, size_t count,
		   read_actor_t actor, void *target)
{
	struct coda_file_info *cfi;
	struct file *host_file;

	cfi = CODA_FTOC(coda_file);
	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
	host_file = cfi->cfi_container;

	if (!host_file->f_op || !host_file->f_op->sendfile)
		return -EINVAL;

	return host_file->f_op->sendfile(host_file, ppos, count, actor, target);
}

static ssize_t
coda_file_write(struct file *coda_file, const char __user *buf, size_t count, loff_t *ppos)
{
	struct inode *host_inode, *coda_inode = coda_file->f_dentry->d_inode;
	struct coda_file_info *cfi;
	struct file *host_file;
	ssize_t ret;

	cfi = CODA_FTOC(coda_file);
	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
	host_file = cfi->cfi_container;

	if (!host_file->f_op || !host_file->f_op->write)
		return -EINVAL;

	host_inode = host_file->f_dentry->d_inode;
	mutex_lock(&coda_inode->i_mutex);

	ret = host_file->f_op->write(host_file, buf, count, ppos);

	coda_inode->i_size = host_inode->i_size;
	coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
	coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC;
	mutex_unlock(&coda_inode->i_mutex);

	return ret;
}

static int
coda_file_mmap(struct file *coda_file, struct vm_area_struct *vma)
{
	struct coda_file_info *cfi;
	struct coda_inode_info *cii;
	struct file *host_file;
	struct inode *coda_inode, *host_inode;

	cfi = CODA_FTOC(coda_file);
	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
	host_file = cfi->cfi_container;

	if (!host_file->f_op || !host_file->f_op->mmap)
		return -ENODEV;

	coda_inode = coda_file->f_dentry->d_inode;
	host_inode = host_file->f_dentry->d_inode;
	coda_file->f_mapping = host_file->f_mapping;
	if (coda_inode->i_mapping == &coda_inode->i_data)
		coda_inode->i_mapping = host_inode->i_mapping;

	/* only allow additional mmaps as long as userspace isn't changing
	 * the container file on us! */
	else if (coda_inode->i_mapping != host_inode->i_mapping)
		return -EBUSY;

	/* keep track of how often the coda_inode/host_file has been mmapped */
	cii = ITOC(coda_inode);
	cii->c_mapcount++;
	cfi->cfi_mapcount++;

	return host_file->f_op->mmap(host_file, vma);
}

int coda_open(struct inode *coda_inode, struct file *coda_file)
{
	struct file *host_file = NULL;
	int error;
	unsigned short flags = coda_file->f_flags & (~O_EXCL);
	unsigned short coda_flags = coda_flags_to_cflags(flags);
	struct coda_file_info *cfi;

	coda_vfs_stat.open++;

	cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
	if (!cfi) {
		unlock_kernel();
		return -ENOMEM;
	}

	lock_kernel();

	error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
			   &host_file); 
	if (error || !host_file) {
		kfree(cfi);
		unlock_kernel();
		return error;
	}

	host_file->f_flags |= coda_file->f_flags & (O_APPEND | O_SYNC);

	cfi->cfi_magic = CODA_MAGIC;
	cfi->cfi_mapcount = 0;
	cfi->cfi_container = host_file;

	BUG_ON(coda_file->private_data != NULL);
	coda_file->private_data = cfi;

	unlock_kernel();
	return 0;
}

int coda_flush(struct file *coda_file)
{
	unsigned short flags = coda_file->f_flags & ~O_EXCL;
	unsigned short coda_flags = coda_flags_to_cflags(flags);
	struct coda_file_info *cfi;
	struct inode *coda_inode;
	int err = 0, fcnt;

	lock_kernel();

	coda_vfs_stat.flush++;

	/* last close semantics */
	fcnt = file_count(coda_file);
	if (fcnt > 1)
		goto out;

	/* No need to make an upcall when we have not made any modifications
	 * to the file */
	if ((coda_file->f_flags & O_ACCMODE) == O_RDONLY)
		goto out;

	if (use_coda_close)
		goto out;

	cfi = CODA_FTOC(coda_file);
	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);

	coda_inode = coda_file->f_dentry->d_inode;

	err = venus_store(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
			  coda_file->f_uid);

	if (err == -EOPNOTSUPP) {
		use_coda_close = 1;
		err = 0;
	}

out:
	unlock_kernel();
	return err;
}

int coda_release(struct inode *coda_inode, struct file *coda_file)
{
	unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
	unsigned short coda_flags = coda_flags_to_cflags(flags);
	struct coda_file_info *cfi;
	struct coda_inode_info *cii;
	struct inode *host_inode;
	int err = 0;

	lock_kernel();
	coda_vfs_stat.release++;
 
	if (!use_coda_close) {
		err = venus_release(coda_inode->i_sb, coda_i2f(coda_inode),
				    coda_flags);
		if (err == -EOPNOTSUPP) {
			use_coda_close = 1;
			err = 0;
		}
	}

	cfi = CODA_FTOC(coda_file);
	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);

	if (use_coda_close)
		err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
				  coda_flags, coda_file->f_uid);

	host_inode = cfi->cfi_container->f_dentry->d_inode;
	cii = ITOC(coda_inode);

	/* did we mmap this file? */
	if (coda_inode->i_mapping == &host_inode->i_data) {
		cii->c_mapcount -= cfi->cfi_mapcount;
		if (!cii->c_mapcount)
			coda_inode->i_mapping = &coda_inode->i_data;
	}

	fput(cfi->cfi_container);
	kfree(coda_file->private_data);
	coda_file->private_data = NULL;

	unlock_kernel();
	return err;
}

int coda_fsync(struct file *coda_file, struct dentry *coda_dentry, int datasync)
{
	struct file *host_file;
	struct dentry *host_dentry;
	struct inode *host_inode, *coda_inode = coda_dentry->d_inode;
	struct coda_file_info *cfi;
	int err = 0;

	if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) ||
	      S_ISLNK(coda_inode->i_mode)))
		return -EINVAL;

	cfi = CODA_FTOC(coda_file);
	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
	host_file = cfi->cfi_container;

	coda_vfs_stat.fsync++;

	if (host_file->f_op && host_file->f_op->fsync) {
		host_dentry = host_file->f_dentry;
		host_inode = host_dentry->d_inode;
		mutex_lock(&host_inode->i_mutex);
		err = host_file->f_op->fsync(host_file, host_dentry, datasync);
		mutex_unlock(&host_inode->i_mutex);
	}

	if ( !err && !datasync ) {
		lock_kernel();
		err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
		unlock_kernel();
	}

	return err;
}

struct file_operations coda_file_operations = {
	.llseek		= generic_file_llseek,
	.read		= coda_file_read,
	.write		= coda_file_write,
	.mmap		= coda_file_mmap,
	.open		= coda_open,
	.flush		= coda_flush,
	.release	= coda_release,
	.fsync		= coda_fsync,
	.sendfile	= coda_file_sendfile,
};
Commit	Line	Data
1da177e4 LT	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 <[email protected]>.
	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/errno.h>
	17	#include <linux/smp_lock.h>
	18	#include <linux/string.h>
	19	#include <asm/uaccess.h>
	20
	21	#include <linux/coda.h>
	22	#include <linux/coda_linux.h>
	23	#include <linux/coda_fs_i.h>
	24	#include <linux/coda_psdev.h>
	25	#include <linux/coda_proc.h>
	26
	27	/* if CODA_STORE fails with EOPNOTSUPP, venus clearly doesn't support
	28	* CODA_STORE/CODA_RELEASE and we fall back on using the CODA_CLOSE upcall */
	29	static int use_coda_close;
	30
	31	static ssize_t
	32	coda_file_read(struct file coda_file, char __user buf, size_t count, loff_t *ppos)
	33	{
	34	struct coda_file_info *cfi;
	35	struct file *host_file;
	36
	37	cfi = CODA_FTOC(coda_file);
	38	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	39	host_file = cfi->cfi_container;
	40
	41	if (!host_file->f_op \|\| !host_file->f_op->read)
	42	return -EINVAL;
	43
	44	return host_file->f_op->read(host_file, buf, count, ppos);
	45	}
	46
	47	static ssize_t
	48	coda_file_sendfile(struct file coda_file, loff_t ppos, size_t count,
	49	read_actor_t actor, void *target)
	50	{
	51	struct coda_file_info *cfi;
	52	struct file *host_file;
	53
	54	cfi = CODA_FTOC(coda_file);
	55	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	56	host_file = cfi->cfi_container;
	57
	58	if (!host_file->f_op \|\| !host_file->f_op->sendfile)
	59	return -EINVAL;
	60
	61	return host_file->f_op->sendfile(host_file, ppos, count, actor, target);
	62	}
	63
	64	static ssize_t
65	coda_file_write(struct file coda_file, const char __user buf, size_t count, loff_t *ppos)
66	{
67	struct inode host_inode, coda_inode = coda_file->f_dentry->d_inode;
68	struct coda_file_info *cfi;
69	struct file *host_file;
70	ssize_t ret;
71
72	cfi = CODA_FTOC(coda_file);
73	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
74	host_file = cfi->cfi_container;
75
76	if (!host_file->f_op \|\| !host_file->f_op->write)
77	return -EINVAL;
78
79	host_inode = host_file->f_dentry->d_inode;
1b1dcc1b	80	mutex_lock(&coda_inode->i_mutex);
1da177e4 LT	81
	82	ret = host_file->f_op->write(host_file, buf, count, ppos);
	83
	84	coda_inode->i_size = host_inode->i_size;
	85	coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
	86	coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC;
1b1dcc1b	87	mutex_unlock(&coda_inode->i_mutex);
1da177e4 LT	88
	89	return ret;
	90	}
	91
	92	static int
	93	coda_file_mmap(struct file coda_file, struct vm_area_struct vma)
	94	{
	95	struct coda_file_info *cfi;
	96	struct coda_inode_info *cii;
	97	struct file *host_file;
	98	struct inode coda_inode, host_inode;
	99
	100	cfi = CODA_FTOC(coda_file);
	101	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	102	host_file = cfi->cfi_container;
	103
	104	if (!host_file->f_op \|\| !host_file->f_op->mmap)
	105	return -ENODEV;
	106
	107	coda_inode = coda_file->f_dentry->d_inode;
	108	host_inode = host_file->f_dentry->d_inode;
	109	coda_file->f_mapping = host_file->f_mapping;
	110	if (coda_inode->i_mapping == &coda_inode->i_data)
	111	coda_inode->i_mapping = host_inode->i_mapping;
	112
	113	/* only allow additional mmaps as long as userspace isn't changing
	114	* the container file on us! */
	115	else if (coda_inode->i_mapping != host_inode->i_mapping)
	116	return -EBUSY;
	117
	118	/* keep track of how often the coda_inode/host_file has been mmapped */
	119	cii = ITOC(coda_inode);
	120	cii->c_mapcount++;
	121	cfi->cfi_mapcount++;
	122
	123	return host_file->f_op->mmap(host_file, vma);
	124	}
	125
	126	int coda_open(struct inode coda_inode, struct file coda_file)
	127	{
	128	struct file *host_file = NULL;
	129	int error;
	130	unsigned short flags = coda_file->f_flags & (~O_EXCL);
	131	unsigned short coda_flags = coda_flags_to_cflags(flags);
	132	struct coda_file_info *cfi;
	133
	134	coda_vfs_stat.open++;
	135
	136	cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
	137	if (!cfi) {
	138	unlock_kernel();
	139	return -ENOMEM;
	140	}
	141
	142	lock_kernel();
	143
	144	error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
	145	&host_file);
	146	if (error \|\| !host_file) {
	147	kfree(cfi);
	148	unlock_kernel();
	149	return error;
	150	}
	151
152	host_file->f_flags \|= coda_file->f_flags & (O_APPEND \| O_SYNC);
153
154	cfi->cfi_magic = CODA_MAGIC;
155	cfi->cfi_mapcount = 0;
156	cfi->cfi_container = host_file;
157
158	BUG_ON(coda_file->private_data != NULL);
159	coda_file->private_data = cfi;
160
161	unlock_kernel();
162	return 0;
163	}
164
165	int coda_flush(struct file *coda_file)
166	{
167	unsigned short flags = coda_file->f_flags & ~O_EXCL;
168	unsigned short coda_flags = coda_flags_to_cflags(flags);
169	struct coda_file_info *cfi;
170	struct inode *coda_inode;
171	int err = 0, fcnt;
172
173	lock_kernel();
174
175	coda_vfs_stat.flush++;
176
177	/* last close semantics */
178	fcnt = file_count(coda_file);
179	if (fcnt > 1)
180	goto out;
181
182	/* No need to make an upcall when we have not made any modifications
183	* to the file */
184	if ((coda_file->f_flags & O_ACCMODE) == O_RDONLY)
185	goto out;
186
187	if (use_coda_close)
188	goto out;
189
190	cfi = CODA_FTOC(coda_file);
191	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
192
193	coda_inode = coda_file->f_dentry->d_inode;
194
195	err = venus_store(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
196	coda_file->f_uid);
197
198	if (err == -EOPNOTSUPP) {
199	use_coda_close = 1;
200	err = 0;
201	}
202
203	out:
204	unlock_kernel();
205	return err;
206	}
207
208	int coda_release(struct inode coda_inode, struct file coda_file)
209	{
210	unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
211	unsigned short coda_flags = coda_flags_to_cflags(flags);
212	struct coda_file_info *cfi;
213	struct coda_inode_info *cii;
214	struct inode *host_inode;
215	int err = 0;
216
217	lock_kernel();
218	coda_vfs_stat.release++;
219
220	if (!use_coda_close) {
221	err = venus_release(coda_inode->i_sb, coda_i2f(coda_inode),
222	coda_flags);
223	if (err == -EOPNOTSUPP) {
224	use_coda_close = 1;
225	err = 0;
226	}
227	}
228
229	cfi = CODA_FTOC(coda_file);
230	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
231
232	if (use_coda_close)
233	err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
234	coda_flags, coda_file->f_uid);
235
236	host_inode = cfi->cfi_container->f_dentry->d_inode;
237	cii = ITOC(coda_inode);
238
239	/* did we mmap this file? */
240	if (coda_inode->i_mapping == &host_inode->i_data) {
241	cii->c_mapcount -= cfi->cfi_mapcount;
242	if (!cii->c_mapcount)
243	coda_inode->i_mapping = &coda_inode->i_data;
244	}
245
246	fput(cfi->cfi_container);
247	kfree(coda_file->private_data);
248	coda_file->private_data = NULL;
249
250	unlock_kernel();
251	return err;
252	}
253
254	int coda_fsync(struct file coda_file, struct dentry coda_dentry, int datasync)
255	{
256	struct file *host_file;
257	struct dentry *host_dentry;
258	struct inode host_inode, coda_inode = coda_dentry->d_inode;
259	struct coda_file_info *cfi;
260	int err = 0;
261
262	if (!(S_ISREG(coda_inode->i_mode) \|\| S_ISDIR(coda_inode->i_mode) \|\|
263	S_ISLNK(coda_inode->i_mode)))
264	return -EINVAL;
265
266	cfi = CODA_FTOC(coda_file);
267	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
268	host_file = cfi->cfi_container;
269
270	coda_vfs_stat.fsync++;
271
272	if (host_file->f_op && host_file->f_op->fsync) {
273	host_dentry = host_file->f_dentry;
274	host_inode = host_dentry->d_inode;
1b1dcc1b	275	mutex_lock(&host_inode->i_mutex);
1da177e4	276	err = host_file->f_op->fsync(host_file, host_dentry, datasync);
1b1dcc1b	277	mutex_unlock(&host_inode->i_mutex);
1da177e4 LT	278	}
	279
	280	if ( !err && !datasync ) {
	281	lock_kernel();
	282	err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
	283	unlock_kernel();
	284	}
	285
	286	return err;
	287	}
	288
	289	struct file_operations coda_file_operations = {
	290	.llseek = generic_file_llseek,
	291	.read = coda_file_read,
	292	.write = coda_file_write,
	293	.mmap = coda_file_mmap,
	294	.open = coda_open,
	295	.flush = coda_flush,
	296	.release = coda_release,
	297	.fsync = coda_fsync,
	298	.sendfile = coda_file_sendfile,
	299	};
	300