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

 /*
  * linux/fs/9p/vfs_dir.c
  *
  * This file contains vfs directory ops for the 9P2000 protocol.
  *
  *  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/file.h>
 #include <linux/stat.h>
 #include <linux/string.h>
 #include <linux/sched.h>
 #include <linux/inet.h>
 #include <linux/idr.h>
 #include <linux/slab.h>
 #include <net/9p/9p.h>
 #include <net/9p/client.h>

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

 /**
  * struct p9_rdir - readdir accounting
  * @mutex: mutex protecting readdir
  * @head: start offset of current dirread buffer
  * @tail: end offset of current dirread buffer
  * @buf: dirread buffer
  *
  * private structure for keeping track of readdir
  * allocated on demand
  */

 struct p9_rdir {
 	struct mutex mutex;
 	int head;
 	int tail;
 	uint8_t *buf;
 };

 /**
  * dt_type - return file type
  * @mistat: mistat structure
  *
  */

 static inline int dt_type(struct p9_wstat *mistat)
 {
 	unsigned long perm = mistat->mode;
 	int rettype = DT_REG;

 	if (perm & P9_DMDIR)
 		rettype = DT_DIR;
 	if (perm & P9_DMSYMLINK)
 		rettype = DT_LNK;

 	return rettype;
 }

 static void p9stat_init(struct p9_wstat *stbuf)
 {
 	stbuf->name  = NULL;
 	stbuf->uid   = NULL;
 	stbuf->gid   = NULL;
 	stbuf->muid  = NULL;
 	stbuf->extension = NULL;
 }

 /**
  * v9fs_alloc_rdir_buf - Allocate buffer used for read and readdir
  * @filp: opened file structure
  * @buflen: Length in bytes of buffer to allocate
  *
  */

 static int v9fs_alloc_rdir_buf(struct file *filp, int buflen)
 {
 	struct p9_rdir *rdir;
 	struct p9_fid *fid;
 	int err = 0;

 	fid = filp->private_data;
 	if (!fid->rdir) {
 		rdir = kmalloc(sizeof(struct p9_rdir) + buflen, GFP_KERNEL);

 		if (rdir == NULL) {
 			err = -ENOMEM;
 			goto exit;
 		}
 		spin_lock(&filp->f_dentry->d_lock);
 		if (!fid->rdir) {
 			rdir->buf = (uint8_t *)rdir + sizeof(struct p9_rdir);
 			mutex_init(&rdir->mutex);
 			rdir->head = rdir->tail = 0;
 			fid->rdir = (void *) rdir;
 			rdir = NULL;
 		}
 		spin_unlock(&filp->f_dentry->d_lock);
 		kfree(rdir);
 	}
 exit:
 	return err;
 }

 /**
  * v9fs_dir_readdir - read a directory
  * @filp: opened file structure
  * @dirent: directory structure ???
  * @filldir: function to populate directory structure ???
  *
  */

 static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
 {
 	int over;
 	struct p9_wstat st;
 	int err = 0;
 	struct p9_fid *fid;
 	int buflen;
 	int reclen = 0;
 	struct p9_rdir *rdir;

 	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
 	fid = filp->private_data;

 	buflen = fid->clnt->msize - P9_IOHDRSZ;

 	err = v9fs_alloc_rdir_buf(filp, buflen);
 	if (err)
 		goto exit;
 	rdir = (struct p9_rdir *) fid->rdir;

 	err = mutex_lock_interruptible(&rdir->mutex);
 	if (err)
 		return err;
 	while (err == 0) {
 		if (rdir->tail == rdir->head) {
 			err = v9fs_file_readn(filp, rdir->buf, NULL,
 							buflen, filp->f_pos);
 			if (err <= 0)
 				goto unlock_and_exit;

 			rdir->head = 0;
 			rdir->tail = err;
 		}
 		while (rdir->head < rdir->tail) {
 			p9stat_init(&st);
 			err = p9stat_read(rdir->buf + rdir->head,
 						rdir->tail - rdir->head, &st,
 						fid->clnt->proto_version);
 			if (err) {
 				P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
 				err = -EIO;
 				p9stat_free(&st);
 				goto unlock_and_exit;
 			}
 			reclen = st.size+2;

 			over = filldir(dirent, st.name, strlen(st.name),
 			    filp->f_pos, v9fs_qid2ino(&st.qid), dt_type(&st));

 			p9stat_free(&st);

 			if (over) {
 				err = 0;
 				goto unlock_and_exit;
 			}
 			rdir->head += reclen;
 			filp->f_pos += reclen;
 		}
 	}

 unlock_and_exit:
 	mutex_unlock(&rdir->mutex);
 exit:
 	return err;
 }

 /**
  * v9fs_dir_readdir_dotl - read a directory
  * @filp: opened file structure
  * @dirent: buffer to fill dirent structures
  * @filldir: function to populate dirent structures
  *
  */
 static int v9fs_dir_readdir_dotl(struct file *filp, void *dirent,
 						filldir_t filldir)
 {
 	int over;
 	int err = 0;
 	struct p9_fid *fid;
 	int buflen;
 	struct p9_rdir *rdir;
 	struct p9_dirent curdirent;
 	u64 oldoffset = 0;

 	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
 	fid = filp->private_data;

 	buflen = fid->clnt->msize - P9_READDIRHDRSZ;

 	err = v9fs_alloc_rdir_buf(filp, buflen);
 	if (err)
 		goto exit;
 	rdir = (struct p9_rdir *) fid->rdir;

 	err = mutex_lock_interruptible(&rdir->mutex);
 	if (err)
 		return err;

 	while (err == 0) {
 		if (rdir->tail == rdir->head) {
 			err = p9_client_readdir(fid, rdir->buf, buflen,
 								filp->f_pos);
 			if (err <= 0)
 				goto unlock_and_exit;

 			rdir->head = 0;
 			rdir->tail = err;
 		}

 		while (rdir->head < rdir->tail) {

 			err = p9dirent_read(rdir->buf + rdir->head,
 						buflen - rdir->head, &curdirent,
 						fid->clnt->proto_version);
 			if (err < 0) {
 				P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
 				err = -EIO;
 				goto unlock_and_exit;
 			}

 			/* d_off in dirent structure tracks the offset into
 			 * the next dirent in the dir. However, filldir()
 			 * expects offset into the current dirent. Hence
 			 * while calling filldir send the offset from the
 			 * previous dirent structure.
 			 */
 			over = filldir(dirent, curdirent.d_name,
 					strlen(curdirent.d_name),
 					oldoffset, v9fs_qid2ino(&curdirent.qid),
 					curdirent.d_type);
 			oldoffset = curdirent.d_off;

 			if (over) {
 				err = 0;
 				goto unlock_and_exit;
 			}

 			filp->f_pos = curdirent.d_off;
 			rdir->head += err;
 		}
 	}

 unlock_and_exit:
 	mutex_unlock(&rdir->mutex);
 exit:
 	return err;
 }


 /**
  * v9fs_dir_release - close a directory
  * @inode: inode of the directory
  * @filp: file pointer to a directory
  *
  */

 int v9fs_dir_release(struct inode *inode, struct file *filp)
 {
 	struct p9_fid *fid;

 	fid = filp->private_data;
 	P9_DPRINTK(P9_DEBUG_VFS,
 			"inode: %p filp: %p fid: %d\n", inode, filp, fid->fid);
 	filemap_write_and_wait(inode->i_mapping);
 	p9_client_clunk(fid);
 	return 0;
 }

 const struct file_operations v9fs_dir_operations = {
 	.read = generic_read_dir,
 	.llseek = generic_file_llseek,
 	.readdir = v9fs_dir_readdir,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 };

 const struct file_operations v9fs_dir_operations_dotl = {
 	.read = generic_read_dir,
 	.llseek = generic_file_llseek,
 	.readdir = v9fs_dir_readdir_dotl,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 };
	/*
	* linux/fs/9p/vfs_dir.c
	*
	* This file contains vfs directory ops for the 9P2000 protocol.
	*
	* 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/file.h>
	#include <linux/stat.h>
	#include <linux/string.h>
	#include <linux/sched.h>
	#include <linux/inet.h>
	#include <linux/idr.h>
	#include <linux/slab.h>
	#include <net/9p/9p.h>
	#include <net/9p/client.h>

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

	/**
	* struct p9_rdir - readdir accounting
	* @mutex: mutex protecting readdir
	* @head: start offset of current dirread buffer
	* @tail: end offset of current dirread buffer
	* @buf: dirread buffer
	*
	* private structure for keeping track of readdir
	* allocated on demand
	*/

	struct p9_rdir {
	struct mutex mutex;
	int head;
	int tail;
	uint8_t *buf;
	};

	/**
	* dt_type - return file type
	* @mistat: mistat structure
	*
	*/

	static inline int dt_type(struct p9_wstat *mistat)
	{
	unsigned long perm = mistat->mode;
	int rettype = DT_REG;

	if (perm & P9_DMDIR)
	rettype = DT_DIR;
	if (perm & P9_DMSYMLINK)
	rettype = DT_LNK;

	return rettype;
	}

	static void p9stat_init(struct p9_wstat *stbuf)
	{
	stbuf->name = NULL;
	stbuf->uid = NULL;
	stbuf->gid = NULL;
	stbuf->muid = NULL;
	stbuf->extension = NULL;
	}

	/**
	* v9fs_alloc_rdir_buf - Allocate buffer used for read and readdir
	* @filp: opened file structure
	* @buflen: Length in bytes of buffer to allocate
	*
	*/

	static int v9fs_alloc_rdir_buf(struct file *filp, int buflen)
	{
	struct p9_rdir *rdir;
	struct p9_fid *fid;
	int err = 0;

	fid = filp->private_data;
	if (!fid->rdir) {
	rdir = kmalloc(sizeof(struct p9_rdir) + buflen, GFP_KERNEL);

	if (rdir == NULL) {
	err = -ENOMEM;
	goto exit;
	}
	spin_lock(&filp->f_dentry->d_lock);
	if (!fid->rdir) {
	rdir->buf = (uint8_t *)rdir + sizeof(struct p9_rdir);
	mutex_init(&rdir->mutex);
	rdir->head = rdir->tail = 0;
	fid->rdir = (void *) rdir;
	rdir = NULL;
	}
	spin_unlock(&filp->f_dentry->d_lock);
	kfree(rdir);
	}
	exit:
	return err;
	}

	/**
	* v9fs_dir_readdir - read a directory
	* @filp: opened file structure
	* @dirent: directory structure ???
	* @filldir: function to populate directory structure ???
	*
	*/

	static int v9fs_dir_readdir(struct file filp, void dirent, filldir_t filldir)
	{
	int over;
	struct p9_wstat st;
	int err = 0;
	struct p9_fid *fid;
	int buflen;
	int reclen = 0;
	struct p9_rdir *rdir;

	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
	fid = filp->private_data;

	buflen = fid->clnt->msize - P9_IOHDRSZ;

	err = v9fs_alloc_rdir_buf(filp, buflen);
	if (err)
	goto exit;
	rdir = (struct p9_rdir *) fid->rdir;

	err = mutex_lock_interruptible(&rdir->mutex);
	if (err)
	return err;
	while (err == 0) {
	if (rdir->tail == rdir->head) {
	err = v9fs_file_readn(filp, rdir->buf, NULL,
	buflen, filp->f_pos);
	if (err <= 0)
	goto unlock_and_exit;

	rdir->head = 0;
	rdir->tail = err;
	}
	while (rdir->head < rdir->tail) {
	p9stat_init(&st);
	err = p9stat_read(rdir->buf + rdir->head,
	rdir->tail - rdir->head, &st,
	fid->clnt->proto_version);
	if (err) {
	P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
	err = -EIO;
	p9stat_free(&st);
	goto unlock_and_exit;
	}
	reclen = st.size+2;

	over = filldir(dirent, st.name, strlen(st.name),
	filp->f_pos, v9fs_qid2ino(&st.qid), dt_type(&st));

	p9stat_free(&st);

	if (over) {
	err = 0;
	goto unlock_and_exit;
	}
	rdir->head += reclen;
	filp->f_pos += reclen;
	}
	}

	unlock_and_exit:
	mutex_unlock(&rdir->mutex);
	exit:
	return err;
	}

	/**
	* v9fs_dir_readdir_dotl - read a directory
	* @filp: opened file structure
	* @dirent: buffer to fill dirent structures
	* @filldir: function to populate dirent structures
	*
	*/
	static int v9fs_dir_readdir_dotl(struct file filp, void dirent,
	filldir_t filldir)
	{
	int over;
	int err = 0;
	struct p9_fid *fid;
	int buflen;
	struct p9_rdir *rdir;
	struct p9_dirent curdirent;
	u64 oldoffset = 0;

	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
	fid = filp->private_data;

	buflen = fid->clnt->msize - P9_READDIRHDRSZ;

	err = v9fs_alloc_rdir_buf(filp, buflen);
	if (err)
	goto exit;
	rdir = (struct p9_rdir *) fid->rdir;

	err = mutex_lock_interruptible(&rdir->mutex);
	if (err)
	return err;

	while (err == 0) {
	if (rdir->tail == rdir->head) {
	err = p9_client_readdir(fid, rdir->buf, buflen,
	filp->f_pos);
	if (err <= 0)
	goto unlock_and_exit;

	rdir->head = 0;
	rdir->tail = err;
	}

	while (rdir->head < rdir->tail) {

	err = p9dirent_read(rdir->buf + rdir->head,
	buflen - rdir->head, &curdirent,
	fid->clnt->proto_version);
	if (err < 0) {
	P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
	err = -EIO;
	goto unlock_and_exit;
	}

	/* d_off in dirent structure tracks the offset into
	* the next dirent in the dir. However, filldir()
	* expects offset into the current dirent. Hence
	* while calling filldir send the offset from the
	* previous dirent structure.
	*/
	over = filldir(dirent, curdirent.d_name,
	strlen(curdirent.d_name),
	oldoffset, v9fs_qid2ino(&curdirent.qid),
	curdirent.d_type);
	oldoffset = curdirent.d_off;

	if (over) {
	err = 0;
	goto unlock_and_exit;
	}

	filp->f_pos = curdirent.d_off;
	rdir->head += err;
	}
	}

	unlock_and_exit:
	mutex_unlock(&rdir->mutex);
	exit:
	return err;
	}


	/**
	* v9fs_dir_release - close a directory
	* @inode: inode of the directory
	* @filp: file pointer to a directory
	*
	*/

	int v9fs_dir_release(struct inode inode, struct file filp)
	{
	struct p9_fid *fid;

	fid = filp->private_data;
	P9_DPRINTK(P9_DEBUG_VFS,
	"inode: %p filp: %p fid: %d\n", inode, filp, fid->fid);
	filemap_write_and_wait(inode->i_mapping);
	p9_client_clunk(fid);
	return 0;
	}

	const struct file_operations v9fs_dir_operations = {
	.read = generic_read_dir,
	.llseek = generic_file_llseek,
	.readdir = v9fs_dir_readdir,
	.open = v9fs_file_open,
	.release = v9fs_dir_release,
	};

	const struct file_operations v9fs_dir_operations_dotl = {
	.read = generic_read_dir,
	.llseek = generic_file_llseek,
	.readdir = v9fs_dir_readdir_dotl,
	.open = v9fs_file_open,
	.release = v9fs_dir_release,
	};