[mirror_ubuntu-artful-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 <linux/coda_proc.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;

	coda_vfs_stat.open++;

	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();

	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_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();
	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_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;

	coda_vfs_stat.fsync++;

	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>
	25	#include <linux/coda_proc.h>
	26
c98d8cfb AB	27	#include "coda_int.h"
c98d8cfb AB	28
1da177e4 LT	29	/* if CODA_STORE fails with EOPNOTSUPP, venus clearly doesn't support
	30	* CODA_STORE/CODA_RELEASE and we fall back on using the CODA_CLOSE upcall */
	31	static int use_coda_close;
	32
	33	static ssize_t
	34	coda_file_read(struct file coda_file, char __user buf, size_t count, loff_t *ppos)
	35	{
	36	struct coda_file_info *cfi;
	37	struct file *host_file;
	38
	39	cfi = CODA_FTOC(coda_file);
	40	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	41	host_file = cfi->cfi_container;
	42
	43	if (!host_file->f_op \|\| !host_file->f_op->read)
	44	return -EINVAL;
	45
	46	return host_file->f_op->read(host_file, buf, count, ppos);
	47	}
	48
	49	static ssize_t
5ffc4ef4 JA	50	coda_file_splice_read(struct file coda_file, loff_t ppos,
	51	struct pipe_inode_info *pipe, size_t count,
	52	unsigned int flags)
1da177e4 LT	53	{
	54	struct coda_file_info *cfi;
	55	struct file *host_file;
	56
	57	cfi = CODA_FTOC(coda_file);
	58	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	59	host_file = cfi->cfi_container;
	60
5ffc4ef4	61	if (!host_file->f_op \|\| !host_file->f_op->splice_read)
1da177e4 LT	62	return -EINVAL;
1da177e4 LT	63
5ffc4ef4	64	return host_file->f_op->splice_read(host_file, ppos, pipe, count,flags);
1da177e4 LT	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	{
d4176d32	70	struct inode host_inode, coda_inode = coda_file->f_path.dentry->d_inode;
1da177e4 LT	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
d4176d32	82	host_inode = host_file->f_path.dentry->d_inode;
1b1dcc1b	83	mutex_lock(&coda_inode->i_mutex);
1da177e4 LT	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;
1b1dcc1b	90	mutex_unlock(&coda_inode->i_mutex);
1da177e4 LT	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
d4176d32 JS	110	coda_inode = coda_file->f_path.dentry->d_inode;
d4176d32 JS	111	host_inode = host_file->f_path.dentry->d_inode;
1da177e4 LT	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	coda_vfs_stat.open++;
	138
	139	cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
6ecbc4e1	140	if (!cfi)
1da177e4	141	return -ENOMEM;
1da177e4 LT	142
	143	lock_kernel();
	144
	145	error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
38c2e437 JH	146	&host_file);
	147	if (!host_file)
	148	error = -EIO;
	149
	150	if (error) {
1da177e4 LT	151	kfree(cfi);
	152	unlock_kernel();
	153	return error;
	154	}
	155
	156	host_file->f_flags \|= coda_file->f_flags & (O_APPEND \| O_SYNC);
	157
	158	cfi->cfi_magic = CODA_MAGIC;
	159	cfi->cfi_mapcount = 0;
	160	cfi->cfi_container = host_file;
	161
	162	BUG_ON(coda_file->private_data != NULL);
	163	coda_file->private_data = cfi;
	164
	165	unlock_kernel();
	166	return 0;
	167	}
	168
75e1fcc0	169	int coda_flush(struct file *coda_file, fl_owner_t id)
1da177e4 LT	170	{
	171	unsigned short flags = coda_file->f_flags & ~O_EXCL;
	172	unsigned short coda_flags = coda_flags_to_cflags(flags);
	173	struct coda_file_info *cfi;
	174	struct inode *coda_inode;
	175	int err = 0, fcnt;
	176
	177	lock_kernel();
	178
	179	coda_vfs_stat.flush++;
	180
	181	/* last close semantics */
	182	fcnt = file_count(coda_file);
	183	if (fcnt > 1)
	184	goto out;
	185
	186	/* No need to make an upcall when we have not made any modifications
	187	* to the file */
	188	if ((coda_file->f_flags & O_ACCMODE) == O_RDONLY)
	189	goto out;
	190
	191	if (use_coda_close)
	192	goto out;
	193
	194	cfi = CODA_FTOC(coda_file);
	195	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	196
d4176d32	197	coda_inode = coda_file->f_path.dentry->d_inode;
1da177e4 LT	198
	199	err = venus_store(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
	200	coda_file->f_uid);
	201
	202	if (err == -EOPNOTSUPP) {
	203	use_coda_close = 1;
	204	err = 0;
	205	}
	206
	207	out:
	208	unlock_kernel();
	209	return err;
	210	}
	211
	212	int coda_release(struct inode coda_inode, struct file coda_file)
	213	{
	214	unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
	215	unsigned short coda_flags = coda_flags_to_cflags(flags);
	216	struct coda_file_info *cfi;
	217	struct coda_inode_info *cii;
	218	struct inode *host_inode;
	219	int err = 0;
	220
	221	lock_kernel();
	222	coda_vfs_stat.release++;
	223
	224	if (!use_coda_close) {
	225	err = venus_release(coda_inode->i_sb, coda_i2f(coda_inode),
	226	coda_flags);
	227	if (err == -EOPNOTSUPP) {
	228	use_coda_close = 1;
	229	err = 0;
	230	}
	231	}
	232
	233	cfi = CODA_FTOC(coda_file);
	234	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	235
	236	if (use_coda_close)
	237	err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
	238	coda_flags, coda_file->f_uid);
	239
d4176d32	240	host_inode = cfi->cfi_container->f_path.dentry->d_inode;
1da177e4 LT	241	cii = ITOC(coda_inode);
	242
	243	/* did we mmap this file? */
	244	if (coda_inode->i_mapping == &host_inode->i_data) {
	245	cii->c_mapcount -= cfi->cfi_mapcount;
	246	if (!cii->c_mapcount)
	247	coda_inode->i_mapping = &coda_inode->i_data;
	248	}
	249
	250	fput(cfi->cfi_container);
	251	kfree(coda_file->private_data);
	252	coda_file->private_data = NULL;
	253
	254	unlock_kernel();
	255	return err;
	256	}
	257
	258	int coda_fsync(struct file coda_file, struct dentry coda_dentry, int datasync)
	259	{
	260	struct file *host_file;
	261	struct dentry *host_dentry;
	262	struct inode host_inode, coda_inode = coda_dentry->d_inode;
	263	struct coda_file_info *cfi;
	264	int err = 0;
	265
	266	if (!(S_ISREG(coda_inode->i_mode) \|\| S_ISDIR(coda_inode->i_mode) \|\|
	267	S_ISLNK(coda_inode->i_mode)))
	268	return -EINVAL;
	269
	270	cfi = CODA_FTOC(coda_file);
	271	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	272	host_file = cfi->cfi_container;
	273
	274	coda_vfs_stat.fsync++;
	275
	276	if (host_file->f_op && host_file->f_op->fsync) {
d4176d32	277	host_dentry = host_file->f_path.dentry;
1da177e4	278	host_inode = host_dentry->d_inode;
1b1dcc1b	279	mutex_lock(&host_inode->i_mutex);
1da177e4	280	err = host_file->f_op->fsync(host_file, host_dentry, datasync);
1b1dcc1b	281	mutex_unlock(&host_inode->i_mutex);
1da177e4 LT	282	}
	283
	284	if ( !err && !datasync ) {
	285	lock_kernel();
	286	err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
	287	unlock_kernel();
	288	}
	289
	290	return err;
	291	}
	292
4b6f5d20	293	const struct file_operations coda_file_operations = {
1da177e4 LT	294	.llseek = generic_file_llseek,
	295	.read = coda_file_read,
	296	.write = coda_file_write,
	297	.mmap = coda_file_mmap,
	298	.open = coda_open,
	299	.flush = coda_flush,
	300	.release = coda_release,
	301	.fsync = coda_fsync,
5ffc4ef4	302	.splice_read = coda_file_splice_read,
1da177e4 LT	303	};
1da177e4 LT	304