fs/9p/vfs_file.c - kernel/msm-4.9 - Gitiles

 /*
  *  linux/fs/9p/vfs_file.c
  *
  * This file contians vfs file ops for 9P2000.
  *
  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License version 2
  *  as published by the Free Software Foundation.
  *
  *  This program is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  *  GNU General Public License for more details.
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, write to:
  *  Free Software Foundation
  *  51 Franklin Street, Fifth Floor
  *  Boston, MA  02111-1301  USA
  *
  */

 #include <linux/module.h>
 #include <linux/errno.h>
 #include <linux/fs.h>
 #include <linux/sched.h>
 #include <linux/file.h>
 #include <linux/stat.h>
 #include <linux/string.h>
 #include <linux/inet.h>
 #include <linux/list.h>
 #include <linux/pagemap.h>
 #include <asm/uaccess.h>
 #include <linux/idr.h>
 #include <net/9p/9p.h>
 #include <net/9p/client.h>

 #include "v9fs.h"
 #include "v9fs_vfs.h"
 #include "fid.h"
 #include "cache.h"

 static const struct file_operations v9fs_cached_file_operations;

 /**
  * v9fs_file_open - open a file (or directory)
  * @inode: inode to be opened
  * @file: file being opened
  *
  */

 int v9fs_file_open(struct inode *inode, struct file *file)
 {
 	int err;
 	struct v9fs_session_info *v9ses;
 	struct p9_fid *fid;
 	int omode;

 	P9_DPRINTK(P9_DEBUG_VFS, "inode: %p file: %p \n", inode, file);
 	v9ses = v9fs_inode2v9ses(inode);
 	omode = v9fs_uflags2omode(file->f_flags, v9fs_proto_dotu(v9ses));
 	fid = file->private_data;
 	if (!fid) {
 		fid = v9fs_fid_clone(file->f_path.dentry);
 		if (IS_ERR(fid))
 			return PTR_ERR(fid);

 		err = p9_client_open(fid, omode);
 		if (err < 0) {
 			p9_client_clunk(fid);
 			return err;
 		}
 		if (omode & P9_OTRUNC) {
 			i_size_write(inode, 0);
 			inode->i_blocks = 0;
 		}
 		if ((file->f_flags & O_APPEND) && (!v9fs_proto_dotu(v9ses)))
 			generic_file_llseek(file, 0, SEEK_END);
 	}

 	file->private_data = fid;
 	if ((fid->qid.version) && (v9ses->cache)) {
 		P9_DPRINTK(P9_DEBUG_VFS, "cached");
 		/* enable cached file options */
 		if(file->f_op == &v9fs_file_operations)
 			file->f_op = &v9fs_cached_file_operations;

 #ifdef CONFIG_9P_FSCACHE
 		v9fs_cache_inode_set_cookie(inode, file);
 #endif
 	}

 	return 0;
 }

 /**
  * v9fs_file_lock - lock a file (or directory)
  * @filp: file to be locked
  * @cmd: lock command
  * @fl: file lock structure
  *
  * Bugs: this looks like a local only lock, we should extend into 9P
  *       by using open exclusive
  */

 static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl)
 {
 	int res = 0;
 	struct inode *inode = filp->f_path.dentry->d_inode;

 	P9_DPRINTK(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);

 	/* No mandatory locks */
 	if (__mandatory_lock(inode))
 		return -ENOLCK;

 	if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
 		filemap_write_and_wait(inode->i_mapping);
 		invalidate_mapping_pages(&inode->i_data, 0, -1);
 	}

 	return res;
 }

 /**
  * v9fs_file_readn - read from a file
  * @filp: file pointer to read
  * @data: data buffer to read data into
  * @udata: user data buffer to read data into
  * @count: size of buffer
  * @offset: offset at which to read data
  *
  */

 ssize_t
 v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count,
 	       u64 offset)
 {
 	int n, total;
 	struct p9_fid *fid = filp->private_data;

 	P9_DPRINTK(P9_DEBUG_VFS, "fid %d offset %llu count %d\n", fid->fid,
 					(long long unsigned) offset, count);

 	n = 0;
 	total = 0;
 	do {
 		n = p9_client_read(fid, data, udata, offset, count);
 		if (n <= 0)
 			break;

 		if (data)
 			data += n;
 		if (udata)
 			udata += n;

 		offset += n;
 		count -= n;
 		total += n;
 	} while (count > 0 && n == (fid->clnt->msize - P9_IOHDRSZ));

 	if (n < 0)
 		total = n;

 	return total;
 }

 /**
  * v9fs_file_read - read from a file
  * @filp: file pointer to read
  * @udata: user data buffer to read data into
  * @count: size of buffer
  * @offset: offset at which to read data
  *
  */

 static ssize_t
 v9fs_file_read(struct file *filp, char __user *udata, size_t count,
 	       loff_t * offset)
 {
 	int ret;
 	struct p9_fid *fid;

 	P9_DPRINTK(P9_DEBUG_VFS, "count %zu offset %lld\n", count, *offset);
 	fid = filp->private_data;

 	if (count > (fid->clnt->msize - P9_IOHDRSZ))
 		ret = v9fs_file_readn(filp, NULL, udata, count, *offset);
 	else
 		ret = p9_client_read(fid, NULL, udata, *offset, count);

 	if (ret > 0)
 		*offset += ret;

 	return ret;
 }

 /**
  * v9fs_file_write - write to a file
  * @filp: file pointer to write
  * @data: data buffer to write data from
  * @count: size of buffer
  * @offset: offset at which to write data
  *
  */

 static ssize_t
 v9fs_file_write(struct file *filp, const char __user * data,
 		size_t count, loff_t * offset)
 {
 	int n, rsize, total = 0;
 	struct p9_fid *fid;
 	struct p9_client *clnt;
 	struct inode *inode = filp->f_path.dentry->d_inode;
 	int origin = *offset;
 	unsigned long pg_start, pg_end;

 	P9_DPRINTK(P9_DEBUG_VFS, "data %p count %d offset %x\n", data,
 		(int)count, (int)*offset);

 	fid = filp->private_data;
 	clnt = fid->clnt;

 	rsize = fid->iounit;
 	if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
 		rsize = clnt->msize - P9_IOHDRSZ;

 	do {
 		if (count < rsize)
 			rsize = count;

 		n = p9_client_write(fid, NULL, data+total, origin+total,
 									rsize);
 		if (n <= 0)
 			break;
 		count -= n;
 		total += n;
 	} while (count > 0);

 	if (total > 0) {
 		pg_start = origin >> PAGE_CACHE_SHIFT;
 		pg_end = (origin + total - 1) >> PAGE_CACHE_SHIFT;
 		if (inode->i_mapping && inode->i_mapping->nrpages)
 			invalidate_inode_pages2_range(inode->i_mapping,
 						      pg_start, pg_end);
 		*offset += total;
 		i_size_write(inode, i_size_read(inode) + total);
 		inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
 	}

 	if (n < 0)
 		return n;

 	return total;
 }

 static int v9fs_file_fsync(struct file *filp, struct dentry *dentry,
 					int datasync)
 {
 	struct p9_fid *fid;
 	struct p9_wstat wstat;
 	int retval;

 	P9_DPRINTK(P9_DEBUG_VFS, "filp %p dentry %p datasync %x\n", filp,
 						dentry, datasync);

 	fid = filp->private_data;
 	v9fs_blank_wstat(&wstat);

 	retval = p9_client_wstat(fid, &wstat);
 	return retval;
 }

 static const struct file_operations v9fs_cached_file_operations = {
 	.llseek = generic_file_llseek,
 	.read = do_sync_read,
 	.aio_read = generic_file_aio_read,
 	.write = v9fs_file_write,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 	.lock = v9fs_file_lock,
 	.mmap = generic_file_readonly_mmap,
 	.fsync = v9fs_file_fsync,
 };

 const struct file_operations v9fs_file_operations = {
 	.llseek = generic_file_llseek,
 	.read = v9fs_file_read,
 	.write = v9fs_file_write,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 	.lock = v9fs_file_lock,
 	.mmap = generic_file_readonly_mmap,
 	.fsync = v9fs_file_fsync,
 };
	/*
	* linux/fs/9p/vfs_file.c
	*
	* This file contians vfs file ops for 9P2000.
	*
	* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
	* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2
	* as published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to:
	* Free Software Foundation
	* 51 Franklin Street, Fifth Floor
	* Boston, MA 02111-1301 USA
	*
	*/

	#include <linux/module.h>
	#include <linux/errno.h>
	#include <linux/fs.h>
	#include <linux/sched.h>
	#include <linux/file.h>
	#include <linux/stat.h>
	#include <linux/string.h>
	#include <linux/inet.h>
	#include <linux/list.h>
	#include <linux/pagemap.h>
	#include <asm/uaccess.h>
	#include <linux/idr.h>
	#include <net/9p/9p.h>
	#include <net/9p/client.h>

	#include "v9fs.h"
	#include "v9fs_vfs.h"
	#include "fid.h"
	#include "cache.h"

	static const struct file_operations v9fs_cached_file_operations;

	/**
	* v9fs_file_open - open a file (or directory)
	* @inode: inode to be opened
	* @file: file being opened
	*
	*/

	int v9fs_file_open(struct inode inode, struct file file)
	{
	int err;
	struct v9fs_session_info *v9ses;
	struct p9_fid *fid;
	int omode;

	P9_DPRINTK(P9_DEBUG_VFS, "inode: %p file: %p \n", inode, file);
	v9ses = v9fs_inode2v9ses(inode);
	omode = v9fs_uflags2omode(file->f_flags, v9fs_proto_dotu(v9ses));
	fid = file->private_data;
	if (!fid) {
	fid = v9fs_fid_clone(file->f_path.dentry);
	if (IS_ERR(fid))
	return PTR_ERR(fid);

	err = p9_client_open(fid, omode);
	if (err < 0) {
	p9_client_clunk(fid);
	return err;
	}
	if (omode & P9_OTRUNC) {
	i_size_write(inode, 0);
	inode->i_blocks = 0;
	}
	if ((file->f_flags & O_APPEND) && (!v9fs_proto_dotu(v9ses)))
	generic_file_llseek(file, 0, SEEK_END);
	}

	file->private_data = fid;
	if ((fid->qid.version) && (v9ses->cache)) {
	P9_DPRINTK(P9_DEBUG_VFS, "cached");
	/* enable cached file options */
	if(file->f_op == &v9fs_file_operations)
	file->f_op = &v9fs_cached_file_operations;

	#ifdef CONFIG_9P_FSCACHE
	v9fs_cache_inode_set_cookie(inode, file);
	#endif
	}

	return 0;
	}

	/**
	* v9fs_file_lock - lock a file (or directory)
	* @filp: file to be locked
	* @cmd: lock command
	* @fl: file lock structure
	*
	* Bugs: this looks like a local only lock, we should extend into 9P
	* by using open exclusive
	*/

	static int v9fs_file_lock(struct file filp, int cmd, struct file_lock fl)
	{
	int res = 0;
	struct inode *inode = filp->f_path.dentry->d_inode;

	P9_DPRINTK(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);

	/* No mandatory locks */
	if (__mandatory_lock(inode))
	return -ENOLCK;

	if ((IS_SETLK(cmd) \|\| IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
	filemap_write_and_wait(inode->i_mapping);
	invalidate_mapping_pages(&inode->i_data, 0, -1);
	}

	return res;
	}

	/**
	* v9fs_file_readn - read from a file
	* @filp: file pointer to read
	* @data: data buffer to read data into
	* @udata: user data buffer to read data into
	* @count: size of buffer
	* @offset: offset at which to read data
	*
	*/

	ssize_t
	v9fs_file_readn(struct file filp, char data, char __user *udata, u32 count,
	u64 offset)
	{
	int n, total;
	struct p9_fid *fid = filp->private_data;

	P9_DPRINTK(P9_DEBUG_VFS, "fid %d offset %llu count %d\n", fid->fid,
	(long long unsigned) offset, count);

	n = 0;
	total = 0;
	do {
	n = p9_client_read(fid, data, udata, offset, count);
	if (n <= 0)
	break;

	if (data)
	data += n;
	if (udata)
	udata += n;

	offset += n;
	count -= n;
	total += n;
	} while (count > 0 && n == (fid->clnt->msize - P9_IOHDRSZ));

	if (n < 0)
	total = n;

	return total;
	}

	/**
	* v9fs_file_read - read from a file
	* @filp: file pointer to read
	* @udata: user data buffer to read data into
	* @count: size of buffer
	* @offset: offset at which to read data
	*
	*/

	static ssize_t
	v9fs_file_read(struct file filp, char __user udata, size_t count,
	loff_t * offset)
	{
	int ret;
	struct p9_fid *fid;

	P9_DPRINTK(P9_DEBUG_VFS, "count %zu offset %lld\n", count, *offset);
	fid = filp->private_data;

	if (count > (fid->clnt->msize - P9_IOHDRSZ))
	ret = v9fs_file_readn(filp, NULL, udata, count, *offset);
	else
	ret = p9_client_read(fid, NULL, udata, *offset, count);

	if (ret > 0)
	*offset += ret;

	return ret;
	}

	/**
	* v9fs_file_write - write to a file
	* @filp: file pointer to write
	* @data: data buffer to write data from
	* @count: size of buffer
	* @offset: offset at which to write data
	*
	*/

	static ssize_t
	v9fs_file_write(struct file filp, const char __user data,
	size_t count, loff_t * offset)
	{
	int n, rsize, total = 0;
	struct p9_fid *fid;
	struct p9_client *clnt;
	struct inode *inode = filp->f_path.dentry->d_inode;
	int origin = *offset;
	unsigned long pg_start, pg_end;

	P9_DPRINTK(P9_DEBUG_VFS, "data %p count %d offset %x\n", data,
	(int)count, (int)*offset);

	fid = filp->private_data;
	clnt = fid->clnt;

	rsize = fid->iounit;
	if (!rsize \|\| rsize > clnt->msize-P9_IOHDRSZ)
	rsize = clnt->msize - P9_IOHDRSZ;

	do {
	if (count < rsize)
	rsize = count;

	n = p9_client_write(fid, NULL, data+total, origin+total,
	rsize);
	if (n <= 0)
	break;
	count -= n;
	total += n;
	} while (count > 0);

	if (total > 0) {
	pg_start = origin >> PAGE_CACHE_SHIFT;
	pg_end = (origin + total - 1) >> PAGE_CACHE_SHIFT;
	if (inode->i_mapping && inode->i_mapping->nrpages)
	invalidate_inode_pages2_range(inode->i_mapping,
	pg_start, pg_end);
	*offset += total;
	i_size_write(inode, i_size_read(inode) + total);
	inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
	}

	if (n < 0)
	return n;

	return total;
	}

	static int v9fs_file_fsync(struct file filp, struct dentry dentry,
	int datasync)
	{
	struct p9_fid *fid;
	struct p9_wstat wstat;
	int retval;

	P9_DPRINTK(P9_DEBUG_VFS, "filp %p dentry %p datasync %x\n", filp,
	dentry, datasync);

	fid = filp->private_data;
	v9fs_blank_wstat(&wstat);

	retval = p9_client_wstat(fid, &wstat);
	return retval;
	}

	static const struct file_operations v9fs_cached_file_operations = {
	.llseek = generic_file_llseek,
	.read = do_sync_read,
	.aio_read = generic_file_aio_read,
	.write = v9fs_file_write,
	.open = v9fs_file_open,
	.release = v9fs_dir_release,
	.lock = v9fs_file_lock,
	.mmap = generic_file_readonly_mmap,
	.fsync = v9fs_file_fsync,
	};

	const struct file_operations v9fs_file_operations = {
	.llseek = generic_file_llseek,
	.read = v9fs_file_read,
	.write = v9fs_file_write,
	.open = v9fs_file_open,
	.release = v9fs_dir_release,
	.lock = v9fs_file_lock,
	.mmap = generic_file_readonly_mmap,
	.fsync = v9fs_file_fsync,
	};