[linux-2.6-block.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/cred.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 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;

	err = vfs_fsync(host_file, host_file->f_path.dentry, datasync);
	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>
7596b27d	16	#include <linux/cred.h>
1da177e4 LT	17	#include <linux/errno.h>
	18	#include <linux/smp_lock.h>
	19	#include <linux/string.h>
	20	#include <asm/uaccess.h>
	21
	22	#include <linux/coda.h>
	23	#include <linux/coda_linux.h>
	24	#include <linux/coda_fs_i.h>
	25	#include <linux/coda_psdev.h>
1da177e4	26
c98d8cfb AB	27	#include "coda_int.h"
c98d8cfb AB	28
1da177e4 LT	29	static ssize_t
	30	coda_file_read(struct file coda_file, char __user buf, size_t count, loff_t *ppos)
	31	{
	32	struct coda_file_info *cfi;
	33	struct file *host_file;
	34
	35	cfi = CODA_FTOC(coda_file);
	36	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	37	host_file = cfi->cfi_container;
	38
	39	if (!host_file->f_op \|\| !host_file->f_op->read)
	40	return -EINVAL;
	41
	42	return host_file->f_op->read(host_file, buf, count, ppos);
	43	}
	44
	45	static ssize_t
5ffc4ef4 JA	46	coda_file_splice_read(struct file coda_file, loff_t ppos,
	47	struct pipe_inode_info *pipe, size_t count,
	48	unsigned int flags)
1da177e4 LT	49	{
	50	struct coda_file_info *cfi;
	51	struct file *host_file;
	52
	53	cfi = CODA_FTOC(coda_file);
	54	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	55	host_file = cfi->cfi_container;
	56
5ffc4ef4	57	if (!host_file->f_op \|\| !host_file->f_op->splice_read)
1da177e4 LT	58	return -EINVAL;
1da177e4 LT	59
5ffc4ef4	60	return host_file->f_op->splice_read(host_file, ppos, pipe, count,flags);
1da177e4 LT	61	}
	62
	63	static ssize_t
	64	coda_file_write(struct file coda_file, const char __user buf, size_t count, loff_t *ppos)
	65	{
d4176d32	66	struct inode host_inode, coda_inode = coda_file->f_path.dentry->d_inode;
1da177e4 LT	67	struct coda_file_info *cfi;
	68	struct file *host_file;
	69	ssize_t ret;
	70
	71	cfi = CODA_FTOC(coda_file);
	72	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	73	host_file = cfi->cfi_container;
	74
	75	if (!host_file->f_op \|\| !host_file->f_op->write)
	76	return -EINVAL;
	77
d4176d32	78	host_inode = host_file->f_path.dentry->d_inode;
1b1dcc1b	79	mutex_lock(&coda_inode->i_mutex);
1da177e4 LT	80
	81	ret = host_file->f_op->write(host_file, buf, count, ppos);
	82
	83	coda_inode->i_size = host_inode->i_size;
	84	coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
	85	coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC;
1b1dcc1b	86	mutex_unlock(&coda_inode->i_mutex);
1da177e4 LT	87
	88	return ret;
	89	}
	90
	91	static int
	92	coda_file_mmap(struct file coda_file, struct vm_area_struct vma)
	93	{
	94	struct coda_file_info *cfi;
	95	struct coda_inode_info *cii;
	96	struct file *host_file;
	97	struct inode coda_inode, host_inode;
	98
	99	cfi = CODA_FTOC(coda_file);
	100	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	101	host_file = cfi->cfi_container;
	102
	103	if (!host_file->f_op \|\| !host_file->f_op->mmap)
	104	return -ENODEV;
	105
d4176d32 JS	106	coda_inode = coda_file->f_path.dentry->d_inode;
d4176d32 JS	107	host_inode = host_file->f_path.dentry->d_inode;
1da177e4 LT	108	coda_file->f_mapping = host_file->f_mapping;
	109	if (coda_inode->i_mapping == &coda_inode->i_data)
	110	coda_inode->i_mapping = host_inode->i_mapping;
	111
	112	/* only allow additional mmaps as long as userspace isn't changing
	113	* the container file on us! */
	114	else if (coda_inode->i_mapping != host_inode->i_mapping)
	115	return -EBUSY;
	116
	117	/* keep track of how often the coda_inode/host_file has been mmapped */
	118	cii = ITOC(coda_inode);
	119	cii->c_mapcount++;
	120	cfi->cfi_mapcount++;
	121
	122	return host_file->f_op->mmap(host_file, vma);
	123	}
	124
	125	int coda_open(struct inode coda_inode, struct file coda_file)
	126	{
	127	struct file *host_file = NULL;
	128	int error;
	129	unsigned short flags = coda_file->f_flags & (~O_EXCL);
	130	unsigned short coda_flags = coda_flags_to_cflags(flags);
	131	struct coda_file_info *cfi;
	132
1da177e4	133	cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
6ecbc4e1	134	if (!cfi)
1da177e4	135	return -ENOMEM;
1da177e4 LT	136
	137	lock_kernel();
	138
	139	error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
38c2e437 JH	140	&host_file);
	141	if (!host_file)
	142	error = -EIO;
	143
	144	if (error) {
1da177e4 LT	145	kfree(cfi);
	146	unlock_kernel();
	147	return error;
	148	}
	149
	150	host_file->f_flags \|= coda_file->f_flags & (O_APPEND \| O_SYNC);
	151
	152	cfi->cfi_magic = CODA_MAGIC;
	153	cfi->cfi_mapcount = 0;
	154	cfi->cfi_container = host_file;
	155
	156	BUG_ON(coda_file->private_data != NULL);
	157	coda_file->private_data = cfi;
	158
	159	unlock_kernel();
	160	return 0;
	161	}
	162
1da177e4 LT	163	int coda_release(struct inode coda_inode, struct file coda_file)
	164	{
	165	unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
	166	unsigned short coda_flags = coda_flags_to_cflags(flags);
	167	struct coda_file_info *cfi;
	168	struct coda_inode_info *cii;
	169	struct inode *host_inode;
	170	int err = 0;
	171
	172	lock_kernel();
3cf01f28	173
1da177e4 LT	174	cfi = CODA_FTOC(coda_file);
	175	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	176
d3fec424	177	err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
d76b0d9b	178	coda_flags, coda_file->f_cred->fsuid);
1da177e4	179
d4176d32	180	host_inode = cfi->cfi_container->f_path.dentry->d_inode;
1da177e4 LT	181	cii = ITOC(coda_inode);
	182
	183	/* did we mmap this file? */
	184	if (coda_inode->i_mapping == &host_inode->i_data) {
	185	cii->c_mapcount -= cfi->cfi_mapcount;
	186	if (!cii->c_mapcount)
	187	coda_inode->i_mapping = &coda_inode->i_data;
	188	}
	189
	190	fput(cfi->cfi_container);
	191	kfree(coda_file->private_data);
	192	coda_file->private_data = NULL;
	193
	194	unlock_kernel();
d3fec424 JH	195
	196	/* VFS fput ignores the return value from file_operations->release, so
	197	* there is no use returning an error here */
	198	return 0;
1da177e4 LT	199	}
	200
	201	int coda_fsync(struct file coda_file, struct dentry coda_dentry, int datasync)
	202	{
	203	struct file *host_file;
4c728ef5	204	struct inode *coda_inode = coda_dentry->d_inode;
1da177e4 LT	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
4c728ef5	216	err = vfs_fsync(host_file, host_file->f_path.dentry, datasync);
1da177e4 LT	217	if ( !err && !datasync ) {
	218	lock_kernel();
	219	err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
	220	unlock_kernel();
	221	}
	222
	223	return err;
	224	}
	225
4b6f5d20	226	const struct file_operations coda_file_operations = {
1da177e4 LT	227	.llseek = generic_file_llseek,
	228	.read = coda_file_read,
	229	.write = coda_file_write,
	230	.mmap = coda_file_mmap,
	231	.open = coda_open,
1da177e4 LT	232	.release = coda_release,
1da177e4 LT	233	.fsync = coda_fsync,
5ffc4ef4	234	.splice_read = coda_file_splice_read,
1da177e4 LT	235	};
1da177e4 LT	236