[linux-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 <linux/slab.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)
{
	ssize_t (*splice_read)(struct file *, loff_t *,
			       struct pipe_inode_info *, size_t, unsigned int);
	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;

	splice_read = host_file->f_op->splice_read;
	if (!splice_read)
		splice_read = default_file_splice_read;

	return 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>
5a0e3ad6	20	#include <linux/slab.h>
1da177e4 LT	21	#include <asm/uaccess.h>
	22
	23	#include <linux/coda.h>
	24	#include <linux/coda_linux.h>
	25	#include <linux/coda_fs_i.h>
	26	#include <linux/coda_psdev.h>
1da177e4	27
c98d8cfb AB	28	#include "coda_int.h"
c98d8cfb AB	29
1da177e4 LT	30	static ssize_t
	31	coda_file_read(struct file coda_file, char __user buf, size_t count, loff_t *ppos)
	32	{
	33	struct coda_file_info *cfi;
	34	struct file *host_file;
	35
	36	cfi = CODA_FTOC(coda_file);
	37	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	38	host_file = cfi->cfi_container;
	39
	40	if (!host_file->f_op \|\| !host_file->f_op->read)
	41	return -EINVAL;
	42
	43	return host_file->f_op->read(host_file, buf, count, ppos);
	44	}
	45
	46	static ssize_t
5ffc4ef4 JA	47	coda_file_splice_read(struct file coda_file, loff_t ppos,
	48	struct pipe_inode_info *pipe, size_t count,
	49	unsigned int flags)
1da177e4	50	{
6818173b MS	51	ssize_t (splice_read)(struct file , loff_t *,
6818173b MS	52	struct pipe_inode_info *, size_t, unsigned int);
1da177e4 LT	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
6818173b MS	60	splice_read = host_file->f_op->splice_read;
	61	if (!splice_read)
	62	splice_read = default_file_splice_read;
1da177e4	63
6818173b	64	return 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
1da177e4	137	cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
6ecbc4e1	138	if (!cfi)
1da177e4	139	return -ENOMEM;
1da177e4 LT	140
	141	lock_kernel();
	142
	143	error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
38c2e437 JH	144	&host_file);
	145	if (!host_file)
	146	error = -EIO;
	147
	148	if (error) {
1da177e4 LT	149	kfree(cfi);
	150	unlock_kernel();
	151	return error;
	152	}
	153
	154	host_file->f_flags \|= coda_file->f_flags & (O_APPEND \| O_SYNC);
	155
	156	cfi->cfi_magic = CODA_MAGIC;
	157	cfi->cfi_mapcount = 0;
	158	cfi->cfi_container = host_file;
	159
	160	BUG_ON(coda_file->private_data != NULL);
	161	coda_file->private_data = cfi;
	162
	163	unlock_kernel();
	164	return 0;
	165	}
	166
1da177e4 LT	167	int coda_release(struct inode coda_inode, struct file coda_file)
	168	{
	169	unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
	170	unsigned short coda_flags = coda_flags_to_cflags(flags);
	171	struct coda_file_info *cfi;
	172	struct coda_inode_info *cii;
	173	struct inode *host_inode;
	174	int err = 0;
	175
	176	lock_kernel();
3cf01f28	177
1da177e4 LT	178	cfi = CODA_FTOC(coda_file);
	179	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	180
d3fec424	181	err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
d76b0d9b	182	coda_flags, coda_file->f_cred->fsuid);
1da177e4	183
d4176d32	184	host_inode = cfi->cfi_container->f_path.dentry->d_inode;
1da177e4 LT	185	cii = ITOC(coda_inode);
	186
	187	/* did we mmap this file? */
	188	if (coda_inode->i_mapping == &host_inode->i_data) {
	189	cii->c_mapcount -= cfi->cfi_mapcount;
	190	if (!cii->c_mapcount)
	191	coda_inode->i_mapping = &coda_inode->i_data;
	192	}
	193
	194	fput(cfi->cfi_container);
	195	kfree(coda_file->private_data);
	196	coda_file->private_data = NULL;
	197
	198	unlock_kernel();
d3fec424 JH	199
	200	/* VFS fput ignores the return value from file_operations->release, so
	201	* there is no use returning an error here */
	202	return 0;
1da177e4 LT	203	}
	204
	205	int coda_fsync(struct file coda_file, struct dentry coda_dentry, int datasync)
	206	{
	207	struct file *host_file;
4c728ef5	208	struct inode *coda_inode = coda_dentry->d_inode;
1da177e4 LT	209	struct coda_file_info *cfi;
	210	int err = 0;
	211
	212	if (!(S_ISREG(coda_inode->i_mode) \|\| S_ISDIR(coda_inode->i_mode) \|\|
	213	S_ISLNK(coda_inode->i_mode)))
	214	return -EINVAL;
	215
	216	cfi = CODA_FTOC(coda_file);
	217	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	218	host_file = cfi->cfi_container;
	219
4c728ef5	220	err = vfs_fsync(host_file, host_file->f_path.dentry, datasync);
1da177e4 LT	221	if ( !err && !datasync ) {
	222	lock_kernel();
	223	err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
	224	unlock_kernel();
	225	}
	226
	227	return err;
	228	}
	229
4b6f5d20	230	const struct file_operations coda_file_operations = {
1da177e4 LT	231	.llseek = generic_file_llseek,
	232	.read = coda_file_read,
	233	.write = coda_file_write,
	234	.mmap = coda_file_mmap,
	235	.open = coda_open,
1da177e4 LT	236	.release = coda_release,
1da177e4 LT	237	.fsync = coda_fsync,
5ffc4ef4	238	.splice_read = coda_file_splice_read,
1da177e4 LT	239	};
1da177e4 LT	240