linux/fs/9p/vfs_dir.c
Venkateswararao Jujjuri (JV) b165d60145 9p: Add datasync to client side TFSYNC/RFSYNC for dotl
SYNOPSIS
    size[4] Tfsync tag[2] fid[4] datasync[4]

    size[4] Rfsync tag[2]

DESCRIPTION

    The Tfsync transaction transfers ("flushes") all modified in-core data of
    file identified by fid to the disk device (or other  permanent  storage
    device)  where that  file  resides.

    If datasync flag is specified data will be fleshed but does not flush
    modified metadata unless  that  metadata  is  needed  in order to allow a
    subsequent data retrieval to be correctly handled.

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2010-10-28 09:08:49 -05:00

319 lines
7 KiB
C

/*
* 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,
rdir->tail - 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,
"v9fs_dir_release: inode: %p filp: %p fid: %d\n",
inode, filp, fid ? fid->fid : -1);
filemap_write_and_wait(inode->i_mapping);
if (fid)
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,
.fsync = v9fs_file_fsync_dotl,
};