[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/spinlock.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <asm/uaccess.h>

#include <linux/coda.h>
#include <linux/coda_psdev.h>

#include "coda_linux.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->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 = file_inode(coda_file);
	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->write)
		return -EINVAL;

	host_inode = file_inode(host_file);
	file_start_write(host_file);
	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);
	file_end_write(host_file);

	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->mmap)
		return -ENODEV;

	coda_inode = file_inode(coda_file);
	host_inode = file_inode(host_file);

	cii = ITOC(coda_inode);
	spin_lock(&cii->c_lock);
	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) {
		spin_unlock(&cii->c_lock);
		return -EBUSY;
	}

	/* keep track of how often the coda_inode/host_file has been mmapped */
	cii->c_mapcount++;
	cfi->cfi_mapcount++;
	spin_unlock(&cii->c_lock);

	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;

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

	if (error) {
		kfree(cfi);
		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;
	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;

	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 = file_inode(cfi->cfi_container);
	cii = ITOC(coda_inode);

	/* did we mmap this file? */
	spin_lock(&cii->c_lock);
	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;
	}
	spin_unlock(&cii->c_lock);

	fput(cfi->cfi_container);
	kfree(coda_file->private_data);
	coda_file->private_data = NULL;

	/* 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, loff_t start, loff_t end, int datasync)
{
	struct file *host_file;
	struct inode *coda_inode = file_inode(coda_file);
	struct coda_file_info *cfi;
	int err;

	if (!(S_ISREG(coda_inode->i_mode) || S_ISDIR(coda_inode->i_mode) ||
	      S_ISLNK(coda_inode->i_mode)))
		return -EINVAL;

	err = filemap_write_and_wait_range(coda_inode->i_mapping, start, end);
	if (err)
		return err;
	mutex_lock(&coda_inode->i_mutex);

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

	err = vfs_fsync(host_file, datasync);
	if (!err && !datasync)
		err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
	mutex_unlock(&coda_inode->i_mutex);

	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	17	#include <linux/errno.h>
b5ce1d83	18	#include <linux/spinlock.h>
1da177e4	19	#include <linux/string.h>
5a0e3ad6	20	#include <linux/slab.h>
1da177e4 LT	21	#include <asm/uaccess.h>
	22
	23	#include <linux/coda.h>
1da177e4	24	#include <linux/coda_psdev.h>
1da177e4	25
31a203df	26	#include "coda_linux.h"
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
72c2d531	39	if (!host_file->f_op->read)
1da177e4 LT	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	49	{
6818173b MS	50	ssize_t (splice_read)(struct file , loff_t *,
6818173b MS	51	struct pipe_inode_info *, size_t, unsigned int);
1da177e4 LT	52	struct coda_file_info *cfi;
	53	struct file *host_file;
	54
	55	cfi = CODA_FTOC(coda_file);
	56	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	57	host_file = cfi->cfi_container;
	58
6818173b MS	59	splice_read = host_file->f_op->splice_read;
	60	if (!splice_read)
	61	splice_read = default_file_splice_read;
1da177e4	62
6818173b	63	return 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	{
496ad9aa	69	struct inode host_inode, coda_inode = file_inode(coda_file);
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
72c2d531	78	if (!host_file->f_op->write)
1da177e4 LT	79	return -EINVAL;
1da177e4 LT	80
496ad9aa	81	host_inode = file_inode(host_file);
03d95eb2	82	file_start_write(host_file);
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);
03d95eb2	91	file_end_write(host_file);
1da177e4 LT	92
	93	return ret;
	94	}
	95
	96	static int
	97	coda_file_mmap(struct file coda_file, struct vm_area_struct vma)
	98	{
	99	struct coda_file_info *cfi;
	100	struct coda_inode_info *cii;
	101	struct file *host_file;
	102	struct inode coda_inode, host_inode;
	103
	104	cfi = CODA_FTOC(coda_file);
	105	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	106	host_file = cfi->cfi_container;
	107
72c2d531	108	if (!host_file->f_op->mmap)
1da177e4 LT	109	return -ENODEV;
1da177e4 LT	110
496ad9aa AV	111	coda_inode = file_inode(coda_file);
496ad9aa AV	112	host_inode = file_inode(host_file);
b5ce1d83 YA	113
	114	cii = ITOC(coda_inode);
	115	spin_lock(&cii->c_lock);
1da177e4 LT	116	coda_file->f_mapping = host_file->f_mapping;
	117	if (coda_inode->i_mapping == &coda_inode->i_data)
	118	coda_inode->i_mapping = host_inode->i_mapping;
	119
	120	/* only allow additional mmaps as long as userspace isn't changing
	121	* the container file on us! */
b5ce1d83 YA	122	else if (coda_inode->i_mapping != host_inode->i_mapping) {
b5ce1d83 YA	123	spin_unlock(&cii->c_lock);
1da177e4	124	return -EBUSY;
b5ce1d83	125	}
1da177e4 LT	126
1da177e4 LT	127	/* keep track of how often the coda_inode/host_file has been mmapped */
1da177e4 LT	128	cii->c_mapcount++;
1da177e4 LT	129	cfi->cfi_mapcount++;
b5ce1d83	130	spin_unlock(&cii->c_lock);
1da177e4 LT	131
	132	return host_file->f_op->mmap(host_file, vma);
	133	}
	134
	135	int coda_open(struct inode coda_inode, struct file coda_file)
	136	{
	137	struct file *host_file = NULL;
	138	int error;
	139	unsigned short flags = coda_file->f_flags & (~O_EXCL);
	140	unsigned short coda_flags = coda_flags_to_cflags(flags);
	141	struct coda_file_info *cfi;
	142
1da177e4	143	cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
6ecbc4e1	144	if (!cfi)
1da177e4	145	return -ENOMEM;
1da177e4	146
1da177e4	147	error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
38c2e437 JH	148	&host_file);
	149	if (!host_file)
	150	error = -EIO;
	151
	152	if (error) {
1da177e4	153	kfree(cfi);
1da177e4 LT	154	return error;
	155	}
	156
	157	host_file->f_flags \|= coda_file->f_flags & (O_APPEND \| O_SYNC);
	158
	159	cfi->cfi_magic = CODA_MAGIC;
	160	cfi->cfi_mapcount = 0;
	161	cfi->cfi_container = host_file;
	162
	163	BUG_ON(coda_file->private_data != NULL);
	164	coda_file->private_data = cfi;
1da177e4 LT	165	return 0;
	166	}
	167
1da177e4 LT	168	int coda_release(struct inode coda_inode, struct file coda_file)
	169	{
	170	unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
	171	unsigned short coda_flags = coda_flags_to_cflags(flags);
	172	struct coda_file_info *cfi;
	173	struct coda_inode_info *cii;
	174	struct inode *host_inode;
f7cc02b8	175	int err;
3cf01f28	176
1da177e4 LT	177	cfi = CODA_FTOC(coda_file);
	178	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	179
d3fec424	180	err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
d76b0d9b	181	coda_flags, coda_file->f_cred->fsuid);
1da177e4	182
496ad9aa	183	host_inode = file_inode(cfi->cfi_container);
1da177e4 LT	184	cii = ITOC(coda_inode);
	185
	186	/* did we mmap this file? */
b5ce1d83	187	spin_lock(&cii->c_lock);
1da177e4 LT	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	}
b5ce1d83	193	spin_unlock(&cii->c_lock);
1da177e4 LT	194
	195	fput(cfi->cfi_container);
	196	kfree(coda_file->private_data);
	197	coda_file->private_data = NULL;
	198
d3fec424 JH	199	/* VFS fput ignores the return value from file_operations->release, so
	200	* there is no use returning an error here */
	201	return 0;
1da177e4 LT	202	}
1da177e4 LT	203
02c24a82	204	int coda_fsync(struct file *coda_file, loff_t start, loff_t end, int datasync)
1da177e4 LT	205	{
1da177e4 LT	206	struct file *host_file;
496ad9aa	207	struct inode *coda_inode = file_inode(coda_file);
1da177e4	208	struct coda_file_info *cfi;
f7cc02b8	209	int err;
1da177e4 LT	210
	211	if (!(S_ISREG(coda_inode->i_mode) \|\| S_ISDIR(coda_inode->i_mode) \|\|
	212	S_ISLNK(coda_inode->i_mode)))
	213	return -EINVAL;
	214
02c24a82 JB	215	err = filemap_write_and_wait_range(coda_inode->i_mapping, start, end);
	216	if (err)
	217	return err;
	218	mutex_lock(&coda_inode->i_mutex);
	219
1da177e4 LT	220	cfi = CODA_FTOC(coda_file);
	221	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	222	host_file = cfi->cfi_container;
	223
8018ab05	224	err = vfs_fsync(host_file, datasync);
f7cc02b8	225	if (!err && !datasync)
1da177e4	226	err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
02c24a82	227	mutex_unlock(&coda_inode->i_mutex);
1da177e4 LT	228
	229	return err;
	230	}
	231
4b6f5d20	232	const struct file_operations coda_file_operations = {
1da177e4 LT	233	.llseek = generic_file_llseek,
	234	.read = coda_file_read,
	235	.write = coda_file_write,
	236	.mmap = coda_file_mmap,
	237	.open = coda_open,
1da177e4 LT	238	.release = coda_release,
1da177e4 LT	239	.fsync = coda_fsync,
5ffc4ef4	240	.splice_read = coda_file_splice_read,
1da177e4 LT	241	};
1da177e4 LT	242