[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 "coda_int.h"

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_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();

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

	err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
			  coda_flags, coda_file->f_cred->fsuid);

	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();

	/* VFS fput ignores the return value from file_operations->release, so
	 * there is no use returning an error here */
	return 0;
}

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,
	.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	static ssize_t
	29	coda_file_read(struct file coda_file, char __user buf, size_t count, loff_t *ppos)
	30	{
	31	struct coda_file_info *cfi;
	32	struct file *host_file;
	33
	34	cfi = CODA_FTOC(coda_file);
	35	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	36	host_file = cfi->cfi_container;
	37
	38	if (!host_file->f_op \|\| !host_file->f_op->read)
	39	return -EINVAL;
	40
	41	return host_file->f_op->read(host_file, buf, count, ppos);
	42	}
	43
	44	static ssize_t
5ffc4ef4 JA	45	coda_file_splice_read(struct file coda_file, loff_t ppos,
	46	struct pipe_inode_info *pipe, size_t count,
	47	unsigned int flags)
1da177e4 LT	48	{
	49	struct coda_file_info *cfi;
	50	struct file *host_file;
	51
	52	cfi = CODA_FTOC(coda_file);
	53	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	54	host_file = cfi->cfi_container;
	55
5ffc4ef4	56	if (!host_file->f_op \|\| !host_file->f_op->splice_read)
1da177e4 LT	57	return -EINVAL;
1da177e4 LT	58
5ffc4ef4	59	return host_file->f_op->splice_read(host_file, ppos, pipe, count,flags);
1da177e4 LT	60	}
	61
	62	static ssize_t
	63	coda_file_write(struct file coda_file, const char __user buf, size_t count, loff_t *ppos)
	64	{
d4176d32	65	struct inode host_inode, coda_inode = coda_file->f_path.dentry->d_inode;
1da177e4 LT	66	struct coda_file_info *cfi;
	67	struct file *host_file;
	68	ssize_t ret;
	69
	70	cfi = CODA_FTOC(coda_file);
	71	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	72	host_file = cfi->cfi_container;
	73
	74	if (!host_file->f_op \|\| !host_file->f_op->write)
	75	return -EINVAL;
	76
d4176d32	77	host_inode = host_file->f_path.dentry->d_inode;
1b1dcc1b	78	mutex_lock(&coda_inode->i_mutex);
1da177e4 LT	79
	80	ret = host_file->f_op->write(host_file, buf, count, ppos);
	81
	82	coda_inode->i_size = host_inode->i_size;
	83	coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
	84	coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC;
1b1dcc1b	85	mutex_unlock(&coda_inode->i_mutex);
1da177e4 LT	86
	87	return ret;
	88	}
	89
	90	static int
	91	coda_file_mmap(struct file coda_file, struct vm_area_struct vma)
	92	{
	93	struct coda_file_info *cfi;
	94	struct coda_inode_info *cii;
	95	struct file *host_file;
	96	struct inode coda_inode, host_inode;
	97
	98	cfi = CODA_FTOC(coda_file);
	99	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	100	host_file = cfi->cfi_container;
	101
	102	if (!host_file->f_op \|\| !host_file->f_op->mmap)
	103	return -ENODEV;
	104
d4176d32 JS	105	coda_inode = coda_file->f_path.dentry->d_inode;
d4176d32 JS	106	host_inode = host_file->f_path.dentry->d_inode;
1da177e4 LT	107	coda_file->f_mapping = host_file->f_mapping;
	108	if (coda_inode->i_mapping == &coda_inode->i_data)
	109	coda_inode->i_mapping = host_inode->i_mapping;
	110
	111	/* only allow additional mmaps as long as userspace isn't changing
	112	* the container file on us! */
	113	else if (coda_inode->i_mapping != host_inode->i_mapping)
	114	return -EBUSY;
	115
	116	/* keep track of how often the coda_inode/host_file has been mmapped */
	117	cii = ITOC(coda_inode);
	118	cii->c_mapcount++;
	119	cfi->cfi_mapcount++;
	120
	121	return host_file->f_op->mmap(host_file, vma);
	122	}
	123
	124	int coda_open(struct inode coda_inode, struct file coda_file)
	125	{
	126	struct file *host_file = NULL;
	127	int error;
	128	unsigned short flags = coda_file->f_flags & (~O_EXCL);
	129	unsigned short coda_flags = coda_flags_to_cflags(flags);
	130	struct coda_file_info *cfi;
	131
1da177e4	132	cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
6ecbc4e1	133	if (!cfi)
1da177e4	134	return -ENOMEM;
1da177e4 LT	135
	136	lock_kernel();
	137
	138	error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
38c2e437 JH	139	&host_file);
	140	if (!host_file)
	141	error = -EIO;
	142
	143	if (error) {
1da177e4 LT	144	kfree(cfi);
	145	unlock_kernel();
	146	return error;
	147	}
	148
	149	host_file->f_flags \|= coda_file->f_flags & (O_APPEND \| O_SYNC);
	150
	151	cfi->cfi_magic = CODA_MAGIC;
	152	cfi->cfi_mapcount = 0;
	153	cfi->cfi_container = host_file;
	154
	155	BUG_ON(coda_file->private_data != NULL);
	156	coda_file->private_data = cfi;
	157
	158	unlock_kernel();
	159	return 0;
	160	}
	161
1da177e4 LT	162	int coda_release(struct inode coda_inode, struct file coda_file)
	163	{
	164	unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
	165	unsigned short coda_flags = coda_flags_to_cflags(flags);
	166	struct coda_file_info *cfi;
	167	struct coda_inode_info *cii;
	168	struct inode *host_inode;
	169	int err = 0;
	170
	171	lock_kernel();
3cf01f28	172
1da177e4 LT	173	cfi = CODA_FTOC(coda_file);
	174	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	175
d3fec424	176	err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
d76b0d9b	177	coda_flags, coda_file->f_cred->fsuid);
1da177e4	178
d4176d32	179	host_inode = cfi->cfi_container->f_path.dentry->d_inode;
1da177e4 LT	180	cii = ITOC(coda_inode);
	181
	182	/* did we mmap this file? */
	183	if (coda_inode->i_mapping == &host_inode->i_data) {
	184	cii->c_mapcount -= cfi->cfi_mapcount;
	185	if (!cii->c_mapcount)
	186	coda_inode->i_mapping = &coda_inode->i_data;
	187	}
	188
	189	fput(cfi->cfi_container);
	190	kfree(coda_file->private_data);
	191	coda_file->private_data = NULL;
	192
	193	unlock_kernel();
d3fec424 JH	194
	195	/* VFS fput ignores the return value from file_operations->release, so
	196	* there is no use returning an error here */
	197	return 0;
1da177e4 LT	198	}
	199
	200	int coda_fsync(struct file coda_file, struct dentry coda_dentry, int datasync)
	201	{
	202	struct file *host_file;
	203	struct dentry *host_dentry;
	204	struct inode host_inode, coda_inode = coda_dentry->d_inode;
	205	struct coda_file_info *cfi;
	206	int err = 0;
	207
	208	if (!(S_ISREG(coda_inode->i_mode) \|\| S_ISDIR(coda_inode->i_mode) \|\|
	209	S_ISLNK(coda_inode->i_mode)))
	210	return -EINVAL;
	211
	212	cfi = CODA_FTOC(coda_file);
	213	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	214	host_file = cfi->cfi_container;
	215
1da177e4	216	if (host_file->f_op && host_file->f_op->fsync) {
d4176d32	217	host_dentry = host_file->f_path.dentry;
1da177e4	218	host_inode = host_dentry->d_inode;
1b1dcc1b	219	mutex_lock(&host_inode->i_mutex);
1da177e4	220	err = host_file->f_op->fsync(host_file, host_dentry, datasync);
1b1dcc1b	221	mutex_unlock(&host_inode->i_mutex);
1da177e4 LT	222	}
	223
	224	if ( !err && !datasync ) {
	225	lock_kernel();
	226	err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
	227	unlock_kernel();
	228	}
	229
	230	return err;
	231	}
	232
4b6f5d20	233	const struct file_operations coda_file_operations = {
1da177e4 LT	234	.llseek = generic_file_llseek,
	235	.read = coda_file_read,
	236	.write = coda_file_write,
	237	.mmap = coda_file_mmap,
	238	.open = coda_open,
1da177e4 LT	239	.release = coda_release,
1da177e4 LT	240	.fsync = coda_fsync,
5ffc4ef4	241	.splice_read = coda_file_splice_read,
1da177e4 LT	242	};
1da177e4 LT	243