[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/spinlock.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/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_iter(struct kiocb *iocb, struct iov_iter *to)
{
	struct file *coda_file = iocb->ki_filp;
	struct coda_file_info *cfi = CODA_FTOC(coda_file);

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

	return vfs_iter_read(cfi->cfi_container, to, &iocb->ki_pos);
}

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_iter(struct kiocb *iocb, struct iov_iter *to)
{
	struct file *coda_file = iocb->ki_filp;
	struct inode *coda_inode = file_inode(coda_file);
	struct coda_file_info *cfi = CODA_FTOC(coda_file);
	struct file *host_file;
	ssize_t ret;

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

	host_file = cfi->cfi_container;
	file_start_write(host_file);
	inode_lock(coda_inode);
	ret = vfs_iter_write(cfi->cfi_container, to, &iocb->ki_pos);
	coda_inode->i_size = file_inode(host_file)->i_size;
	coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
	coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC;
	inode_unlock(coda_inode);
	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;
	inode_lock(coda_inode);

	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));
	inode_unlock(coda_inode);

	return err;
}

const struct file_operations coda_file_operations = {
	.llseek		= generic_file_llseek,
	.read_iter	= coda_file_read_iter,
	.write_iter	= coda_file_write_iter,
	.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>
834b46c3	21	#include <linux/uaccess.h>
1da177e4 LT	22
1da177e4 LT	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	29	static ssize_t
c12c49e7	30	coda_file_read_iter(struct kiocb iocb, struct iov_iter to)
1da177e4	31	{
c12c49e7 AV	32	struct file *coda_file = iocb->ki_filp;
c12c49e7 AV	33	struct coda_file_info *cfi = CODA_FTOC(coda_file);
1da177e4	34
1da177e4	35	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
1da177e4	36
c12c49e7	37	return vfs_iter_read(cfi->cfi_container, to, &iocb->ki_pos);
1da177e4 LT	38	}
	39
	40	static ssize_t
5ffc4ef4 JA	41	coda_file_splice_read(struct file coda_file, loff_t ppos,
	42	struct pipe_inode_info *pipe, size_t count,
	43	unsigned int flags)
1da177e4	44	{
6818173b MS	45	ssize_t (splice_read)(struct file , loff_t *,
6818173b MS	46	struct pipe_inode_info *, size_t, unsigned int);
1da177e4 LT	47	struct coda_file_info *cfi;
	48	struct file *host_file;
	49
	50	cfi = CODA_FTOC(coda_file);
	51	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	52	host_file = cfi->cfi_container;
	53
6818173b MS	54	splice_read = host_file->f_op->splice_read;
	55	if (!splice_read)
	56	splice_read = default_file_splice_read;
1da177e4	57
6818173b	58	return splice_read(host_file, ppos, pipe, count, flags);
1da177e4 LT	59	}
	60
	61	static ssize_t
c12c49e7	62	coda_file_write_iter(struct kiocb iocb, struct iov_iter to)
1da177e4	63	{
c12c49e7 AV	64	struct file *coda_file = iocb->ki_filp;
	65	struct inode *coda_inode = file_inode(coda_file);
	66	struct coda_file_info *cfi = CODA_FTOC(coda_file);
1da177e4 LT	67	struct file *host_file;
	68	ssize_t ret;
	69
1da177e4	70	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
1da177e4	71
c12c49e7	72	host_file = cfi->cfi_container;
03d95eb2	73	file_start_write(host_file);
5955102c	74	inode_lock(coda_inode);
c12c49e7 AV	75	ret = vfs_iter_write(cfi->cfi_container, to, &iocb->ki_pos);
c12c49e7 AV	76	coda_inode->i_size = file_inode(host_file)->i_size;
1da177e4 LT	77	coda_inode->i_blocks = (coda_inode->i_size + 511) >> 9;
1da177e4 LT	78	coda_inode->i_mtime = coda_inode->i_ctime = CURRENT_TIME_SEC;
5955102c	79	inode_unlock(coda_inode);
03d95eb2	80	file_end_write(host_file);
1da177e4 LT	81	return ret;
	82	}
	83
	84	static int
	85	coda_file_mmap(struct file coda_file, struct vm_area_struct vma)
	86	{
	87	struct coda_file_info *cfi;
	88	struct coda_inode_info *cii;
	89	struct file *host_file;
	90	struct inode coda_inode, host_inode;
	91
	92	cfi = CODA_FTOC(coda_file);
	93	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	94	host_file = cfi->cfi_container;
	95
72c2d531	96	if (!host_file->f_op->mmap)
1da177e4 LT	97	return -ENODEV;
1da177e4 LT	98
496ad9aa AV	99	coda_inode = file_inode(coda_file);
496ad9aa AV	100	host_inode = file_inode(host_file);
b5ce1d83 YA	101
	102	cii = ITOC(coda_inode);
	103	spin_lock(&cii->c_lock);
1da177e4 LT	104	coda_file->f_mapping = host_file->f_mapping;
	105	if (coda_inode->i_mapping == &coda_inode->i_data)
	106	coda_inode->i_mapping = host_inode->i_mapping;
	107
	108	/* only allow additional mmaps as long as userspace isn't changing
	109	* the container file on us! */
b5ce1d83 YA	110	else if (coda_inode->i_mapping != host_inode->i_mapping) {
b5ce1d83 YA	111	spin_unlock(&cii->c_lock);
1da177e4	112	return -EBUSY;
b5ce1d83	113	}
1da177e4 LT	114
1da177e4 LT	115	/* keep track of how often the coda_inode/host_file has been mmapped */
1da177e4 LT	116	cii->c_mapcount++;
1da177e4 LT	117	cfi->cfi_mapcount++;
b5ce1d83	118	spin_unlock(&cii->c_lock);
1da177e4 LT	119
	120	return host_file->f_op->mmap(host_file, vma);
	121	}
	122
	123	int coda_open(struct inode coda_inode, struct file coda_file)
	124	{
	125	struct file *host_file = NULL;
	126	int error;
	127	unsigned short flags = coda_file->f_flags & (~O_EXCL);
	128	unsigned short coda_flags = coda_flags_to_cflags(flags);
	129	struct coda_file_info *cfi;
	130
1da177e4	131	cfi = kmalloc(sizeof(struct coda_file_info), GFP_KERNEL);
6ecbc4e1	132	if (!cfi)
1da177e4	133	return -ENOMEM;
1da177e4	134
1da177e4	135	error = venus_open(coda_inode->i_sb, coda_i2f(coda_inode), coda_flags,
38c2e437 JH	136	&host_file);
	137	if (!host_file)
	138	error = -EIO;
	139
	140	if (error) {
1da177e4	141	kfree(cfi);
1da177e4 LT	142	return error;
	143	}
	144
	145	host_file->f_flags \|= coda_file->f_flags & (O_APPEND \| O_SYNC);
	146
	147	cfi->cfi_magic = CODA_MAGIC;
	148	cfi->cfi_mapcount = 0;
	149	cfi->cfi_container = host_file;
	150
	151	BUG_ON(coda_file->private_data != NULL);
	152	coda_file->private_data = cfi;
1da177e4 LT	153	return 0;
	154	}
	155
1da177e4 LT	156	int coda_release(struct inode coda_inode, struct file coda_file)
	157	{
	158	unsigned short flags = (coda_file->f_flags) & (~O_EXCL);
	159	unsigned short coda_flags = coda_flags_to_cflags(flags);
	160	struct coda_file_info *cfi;
	161	struct coda_inode_info *cii;
	162	struct inode *host_inode;
f7cc02b8	163	int err;
3cf01f28	164
1da177e4 LT	165	cfi = CODA_FTOC(coda_file);
	166	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	167
d3fec424	168	err = venus_close(coda_inode->i_sb, coda_i2f(coda_inode),
d76b0d9b	169	coda_flags, coda_file->f_cred->fsuid);
1da177e4	170
496ad9aa	171	host_inode = file_inode(cfi->cfi_container);
1da177e4 LT	172	cii = ITOC(coda_inode);
	173
	174	/* did we mmap this file? */
b5ce1d83	175	spin_lock(&cii->c_lock);
1da177e4 LT	176	if (coda_inode->i_mapping == &host_inode->i_data) {
	177	cii->c_mapcount -= cfi->cfi_mapcount;
	178	if (!cii->c_mapcount)
	179	coda_inode->i_mapping = &coda_inode->i_data;
	180	}
b5ce1d83	181	spin_unlock(&cii->c_lock);
1da177e4 LT	182
	183	fput(cfi->cfi_container);
	184	kfree(coda_file->private_data);
	185	coda_file->private_data = NULL;
	186
d3fec424 JH	187	/* VFS fput ignores the return value from file_operations->release, so
	188	* there is no use returning an error here */
	189	return 0;
1da177e4 LT	190	}
1da177e4 LT	191
02c24a82	192	int coda_fsync(struct file *coda_file, loff_t start, loff_t end, int datasync)
1da177e4 LT	193	{
1da177e4 LT	194	struct file *host_file;
496ad9aa	195	struct inode *coda_inode = file_inode(coda_file);
1da177e4	196	struct coda_file_info *cfi;
f7cc02b8	197	int err;
1da177e4 LT	198
	199	if (!(S_ISREG(coda_inode->i_mode) \|\| S_ISDIR(coda_inode->i_mode) \|\|
	200	S_ISLNK(coda_inode->i_mode)))
	201	return -EINVAL;
	202
02c24a82 JB	203	err = filemap_write_and_wait_range(coda_inode->i_mapping, start, end);
	204	if (err)
	205	return err;
5955102c	206	inode_lock(coda_inode);
02c24a82	207
1da177e4 LT	208	cfi = CODA_FTOC(coda_file);
	209	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	210	host_file = cfi->cfi_container;
	211
8018ab05	212	err = vfs_fsync(host_file, datasync);
f7cc02b8	213	if (!err && !datasync)
1da177e4	214	err = venus_fsync(coda_inode->i_sb, coda_i2f(coda_inode));
5955102c	215	inode_unlock(coda_inode);
1da177e4 LT	216
	217	return err;
	218	}
	219
4b6f5d20	220	const struct file_operations coda_file_operations = {
1da177e4	221	.llseek = generic_file_llseek,
c12c49e7 AV	222	.read_iter = coda_file_read_iter,
c12c49e7 AV	223	.write_iter = coda_file_write_iter,
1da177e4 LT	224	.mmap = coda_file_mmap,
1da177e4 LT	225	.open = coda_open,
1da177e4 LT	226	.release = coda_release,
1da177e4 LT	227	.fsync = coda_fsync,
5ffc4ef4	228	.splice_read = coda_file_splice_read,
1da177e4 LT	229	};
1da177e4 LT	230