[mirror_ubuntu-zesty-kernel.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 <coda@cs.cmu.edu>.
 */

#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 "coda_int.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_splice_read(struct file *coda_file, loff_t *ppos,
		      struct pipe_inode_info *pipe, size_t count,
		      unsigned int flags)
{
	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->splice_read)
		return -EINVAL;

	return host_file->f_op->splice_read(host_file, ppos, pipe, count,flags);
}

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_path.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_path.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_path.dentry->d_inode;
	host_inode = host_file->f_path.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;

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

	lock_kernel();

	error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
			   &host_file);
	if (!host_file)
		error = -EIO;

	if (error) {
		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, fl_owner_t id)
{
	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();

	/* 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_path.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();

	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_path.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;

	if (host_file->f_op && host_file->f_op->fsync) {
		host_dentry = host_file->f_path.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;
}

const 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,
	.splice_read	= coda_file_splice_read,
};
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 <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/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>
1da177e4	25
c98d8cfb AB	26	#include "coda_int.h"
c98d8cfb AB	27
1da177e4 LT	28	/* if CODA_STORE fails with EOPNOTSUPP, venus clearly doesn't support
	29	* CODA_STORE/CODA_RELEASE and we fall back on using the CODA_CLOSE upcall */
	30	static int use_coda_close;
	31
	32	static ssize_t
	33	coda_file_read(struct file coda_file, char __user buf, size_t count, loff_t *ppos)
	34	{
	35	struct coda_file_info *cfi;
	36	struct file *host_file;
	37
	38	cfi = CODA_FTOC(coda_file);
	39	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	40	host_file = cfi->cfi_container;
	41
	42	if (!host_file->f_op \|\| !host_file->f_op->read)
	43	return -EINVAL;
	44
	45	return host_file->f_op->read(host_file, buf, count, ppos);
	46	}
	47
	48	static ssize_t
5ffc4ef4 JA	49	coda_file_splice_read(struct file coda_file, loff_t ppos,
	50	struct pipe_inode_info *pipe, size_t count,
	51	unsigned int flags)
1da177e4 LT	52	{
	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
5ffc4ef4	60	if (!host_file->f_op \|\| !host_file->f_op->splice_read)
1da177e4 LT	61	return -EINVAL;
1da177e4 LT	62
5ffc4ef4	63	return host_file->f_op->splice_read(host_file, ppos, pipe, count,flags);
1da177e4 LT	64	}
	65
	66	static ssize_t
	67	coda_file_write(struct file coda_file, const char __user buf, size_t count, loff_t *ppos)
	68	{
d4176d32	69	struct inode host_inode, coda_inode = coda_file->f_path.dentry->d_inode;
1da177e4 LT	70	struct coda_file_info *cfi;
	71	struct file *host_file;
	72	ssize_t ret;
	73
	74	cfi = CODA_FTOC(coda_file);
	75	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	76	host_file = cfi->cfi_container;
	77
	78	if (!host_file->f_op \|\| !host_file->f_op->write)
	79	return -EINVAL;
	80
d4176d32	81	host_inode = host_file->f_path.dentry->d_inode;
1b1dcc1b	82	mutex_lock(&coda_inode->i_mutex);
1da177e4 LT	83
	84	ret = host_file->f_op->write(host_file, buf, count, ppos);
	85
	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;
1b1dcc1b	89	mutex_unlock(&coda_inode->i_mutex);
1da177e4 LT	90
	91	return ret;
	92	}
	93
	94	static int
	95	coda_file_mmap(struct file coda_file, struct vm_area_struct vma)
	96	{
	97	struct coda_file_info *cfi;
	98	struct coda_inode_info *cii;
	99	struct file *host_file;
	100	struct inode coda_inode, host_inode;
	101
	102	cfi = CODA_FTOC(coda_file);
	103	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	104	host_file = cfi->cfi_container;
	105
	106	if (!host_file->f_op \|\| !host_file->f_op->mmap)
	107	return -ENODEV;
	108
d4176d32 JS	109	coda_inode = coda_file->f_path.dentry->d_inode;
d4176d32 JS	110	host_inode = host_file->f_path.dentry->d_inode;
1da177e4 LT	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;
	114
	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)
	118	return -EBUSY;
	119
	120	/* keep track of how often the coda_inode/host_file has been mmapped */
	121	cii = ITOC(coda_inode);
	122	cii->c_mapcount++;
	123	cfi->cfi_mapcount++;
	124
	125	return host_file->f_op->mmap(host_file, vma);
	126	}
	127
	128	int coda_open(struct inode coda_inode, struct file coda_file)
	129	{
	130	struct file *host_file = NULL;
	131	int error;
	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;
	135
1da177e4	136	cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
6ecbc4e1	137	if (!cfi)
1da177e4	138	return -ENOMEM;
1da177e4 LT	139
	140	lock_kernel();
	141
	142	error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
38c2e437 JH	143	&host_file);
	144	if (!host_file)
	145	error = -EIO;
	146
	147	if (error) {
1da177e4 LT	148	kfree(cfi);
	149	unlock_kernel();
	150	return error;
	151	}
	152
	153	host_file->f_flags \|= coda_file->f_flags & (O_APPEND \| O_SYNC);
	154
	155	cfi->cfi_magic = CODA_MAGIC;
	156	cfi->cfi_mapcount = 0;
	157	cfi->cfi_container = host_file;
	158
	159	BUG_ON(coda_file->private_data != NULL);
	160	coda_file->private_data = cfi;
	161
	162	unlock_kernel();
	163	return 0;
	164	}
	165
75e1fcc0	166	int coda_flush(struct file *coda_file, fl_owner_t id)
1da177e4 LT	167	{
	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 inode *coda_inode;
	172	int err = 0, fcnt;
	173
	174	lock_kernel();
	175
1da177e4 LT	176	/* last close semantics */
	177	fcnt = file_count(coda_file);
	178	if (fcnt > 1)
	179	goto out;
	180
	181	/* No need to make an upcall when we have not made any modifications
	182	* to the file */
	183	if ((coda_file->f_flags & O_ACCMODE) == O_RDONLY)
	184	goto out;
	185
	186	if (use_coda_close)
	187	goto out;
	188
	189	cfi = CODA_FTOC(coda_file);
	190	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	191
d4176d32	192	coda_inode = coda_file->f_path.dentry->d_inode;
1da177e4 LT	193
	194	err = venus_store(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
	195	coda_file->f_uid);
	196
	197	if (err == -EOPNOTSUPP) {
	198	use_coda_close = 1;
	199	err = 0;
	200	}
	201
	202	out:
	203	unlock_kernel();
	204	return err;
	205	}
	206
	207	int coda_release(struct inode coda_inode, struct file coda_file)
	208	{
	209	unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
	210	unsigned short coda_flags = coda_flags_to_cflags(flags);
	211	struct coda_file_info *cfi;
	212	struct coda_inode_info *cii;
	213	struct inode *host_inode;
	214	int err = 0;
	215
	216	lock_kernel();
3cf01f28	217
1da177e4 LT	218	if (!use_coda_close) {
	219	err = venus_release(coda_inode->i_sb, coda_i2f(coda_inode),
	220	coda_flags);
	221	if (err == -EOPNOTSUPP) {
	222	use_coda_close = 1;
	223	err = 0;
	224	}
	225	}
	226
	227	cfi = CODA_FTOC(coda_file);
	228	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	229
	230	if (use_coda_close)
	231	err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
	232	coda_flags, coda_file->f_uid);
	233
d4176d32	234	host_inode = cfi->cfi_container->f_path.dentry->d_inode;
1da177e4 LT	235	cii = ITOC(coda_inode);
	236
	237	/* did we mmap this file? */
	238	if (coda_inode->i_mapping == &host_inode->i_data) {
	239	cii->c_mapcount -= cfi->cfi_mapcount;
	240	if (!cii->c_mapcount)
	241	coda_inode->i_mapping = &coda_inode->i_data;
	242	}
	243
	244	fput(cfi->cfi_container);
	245	kfree(coda_file->private_data);
	246	coda_file->private_data = NULL;
	247
	248	unlock_kernel();
	249	return err;
	250	}
	251
	252	int coda_fsync(struct file coda_file, struct dentry coda_dentry, int datasync)
	253	{
	254	struct file *host_file;
	255	struct dentry *host_dentry;
	256	struct inode host_inode, coda_inode = coda_dentry->d_inode;
	257	struct coda_file_info *cfi;
	258	int err = 0;
	259
	260	if (!(S_ISREG(coda_inode->i_mode) \|\| S_ISDIR(coda_inode->i_mode) \|\|
	261	S_ISLNK(coda_inode->i_mode)))
	262	return -EINVAL;
	263
	264	cfi = CODA_FTOC(coda_file);
	265	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	266	host_file = cfi->cfi_container;
	267
1da177e4	268	if (host_file->f_op && host_file->f_op->fsync) {
d4176d32	269	host_dentry = host_file->f_path.dentry;
1da177e4	270	host_inode = host_dentry->d_inode;
1b1dcc1b	271	mutex_lock(&host_inode->i_mutex);
1da177e4	272	err = host_file->f_op->fsync(host_file, host_dentry, datasync);
1b1dcc1b	273	mutex_unlock(&host_inode->i_mutex);
1da177e4 LT	274	}
	275
	276	if ( !err && !datasync ) {
	277	lock_kernel();
	278	err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
	279	unlock_kernel();
	280	}
	281
	282	return err;
	283	}
	284
4b6f5d20	285	const struct file_operations coda_file_operations = {
1da177e4 LT	286	.llseek = generic_file_llseek,
	287	.read = coda_file_read,
	288	.write = coda_file_write,
	289	.mmap = coda_file_mmap,
	290	.open = coda_open,
	291	.flush = coda_flush,
	292	.release = coda_release,
	293	.fsync = coda_fsync,
5ffc4ef4	294	.splice_read = coda_file_splice_read,
1da177e4 LT	295	};
1da177e4 LT	296