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-rw-r--r--fs/9p/vfs_file.c401
1 files changed, 401 insertions, 0 deletions
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
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index 000000000000..1f8ae7d580ab
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+++ b/fs/9p/vfs_file.c
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+/*
+ * 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 as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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/smp_lock.h>
+#include <linux/inet.h>
+#include <linux/version.h>
+#include <linux/list.h>
+#include <asm/uaccess.h>
+#include <linux/idr.h>
+
+#include "debug.h"
+#include "v9fs.h"
+#include "9p.h"
+#include "v9fs_vfs.h"
+#include "fid.h"
+
+/**
+ * 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)
+{
+ struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
+ struct v9fs_fid *v9fid = v9fs_fid_lookup(file->f_dentry, FID_WALK);
+ struct v9fs_fid *v9newfid = NULL;
+ struct v9fs_fcall *fcall = NULL;
+ int open_mode = 0;
+ unsigned int iounit = 0;
+ int newfid = -1;
+ long result = -1;
+
+ dprintk(DEBUG_VFS, "inode: %p file: %p v9fid= %p\n", inode, file,
+ v9fid);
+
+ if (!v9fid) {
+ struct dentry *dentry = file->f_dentry;
+ dprintk(DEBUG_ERROR, "Couldn't resolve fid from dentry\n");
+
+ /* XXX - some duplication from lookup, generalize later */
+ /* basically vfs_lookup is too heavy weight */
+ v9fid = v9fs_fid_lookup(file->f_dentry, FID_OP);
+ if (!v9fid)
+ return -EBADF;
+
+ v9fid = v9fs_fid_lookup(dentry->d_parent, FID_WALK);
+ if (!v9fid)
+ return -EBADF;
+
+ newfid = v9fs_get_idpool(&v9ses->fidpool);
+ if (newfid < 0) {
+ eprintk(KERN_WARNING, "newfid fails!\n");
+ return -ENOSPC;
+ }
+
+ result =
+ v9fs_t_walk(v9ses, v9fid->fid, newfid,
+ (char *)file->f_dentry->d_name.name, NULL);
+ if (result < 0) {
+ v9fs_put_idpool(newfid, &v9ses->fidpool);
+ dprintk(DEBUG_ERROR, "rewalk didn't work\n");
+ return -EBADF;
+ }
+
+ v9fid = v9fs_fid_create(dentry);
+ if (v9fid == NULL) {
+ dprintk(DEBUG_ERROR, "couldn't insert\n");
+ return -ENOMEM;
+ }
+ v9fid->fid = newfid;
+ }
+
+ if (v9fid->fidcreate) {
+ /* create case */
+ newfid = v9fid->fid;
+ iounit = v9fid->iounit;
+ v9fid->fidcreate = 0;
+ } else {
+ if (!S_ISDIR(inode->i_mode))
+ newfid = v9fid->fid;
+ else {
+ newfid = v9fs_get_idpool(&v9ses->fidpool);
+ if (newfid < 0) {
+ eprintk(KERN_WARNING, "allocation failed\n");
+ return -ENOSPC;
+ }
+ /* This would be a somewhat critical clone */
+ result =
+ v9fs_t_walk(v9ses, v9fid->fid, newfid, NULL,
+ &fcall);
+ if (result < 0) {
+ dprintk(DEBUG_ERROR, "clone error: %s\n",
+ FCALL_ERROR(fcall));
+ kfree(fcall);
+ return result;
+ }
+
+ v9newfid = v9fs_fid_create(file->f_dentry);
+ v9newfid->fid = newfid;
+ v9newfid->qid = v9fid->qid;
+ v9newfid->iounit = v9fid->iounit;
+ v9newfid->fidopen = 0;
+ v9newfid->fidclunked = 0;
+ v9newfid->v9ses = v9ses;
+ v9fid = v9newfid;
+ kfree(fcall);
+ }
+
+ /* TODO: do special things for O_EXCL, O_NOFOLLOW, O_SYNC */
+ /* translate open mode appropriately */
+ open_mode = file->f_flags & 0x3;
+
+ if (file->f_flags & O_EXCL)
+ open_mode |= V9FS_OEXCL;
+
+ if (v9ses->extended) {
+ if (file->f_flags & O_TRUNC)
+ open_mode |= V9FS_OTRUNC;
+
+ if (file->f_flags & O_APPEND)
+ open_mode |= V9FS_OAPPEND;
+ }
+
+ result = v9fs_t_open(v9ses, newfid, open_mode, &fcall);
+ if (result < 0) {
+ dprintk(DEBUG_ERROR,
+ "open failed, open_mode 0x%x: %s\n", open_mode,
+ FCALL_ERROR(fcall));
+ kfree(fcall);
+ return result;
+ }
+
+ iounit = fcall->params.ropen.iounit;
+ kfree(fcall);
+ }
+
+
+ file->private_data = v9fid;
+
+ v9fid->rdir_pos = 0;
+ v9fid->rdir_fcall = NULL;
+ v9fid->fidopen = 1;
+ v9fid->filp = file;
+ v9fid->iounit = iounit;
+
+ return 0;
+}
+
+/**
+ * v9fs_file_lock - lock a file (or directory)
+ * @inode: inode to be opened
+ * @file: file being opened
+ *
+ * XXX - 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_dentry->d_inode;
+
+ dprintk(DEBUG_VFS, "filp: %p lock: %p\n", filp, fl);
+
+ /* No mandatory locks */
+ if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
+ return -ENOLCK;
+
+ if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) {
+ filemap_fdatawrite(inode->i_mapping);
+ filemap_fdatawait(inode->i_mapping);
+ invalidate_inode_pages(&inode->i_data);
+ }
+
+ return res;
+}
+
+/**
+ * v9fs_read - read from a file (internal)
+ * @filep: file pointer to read
+ * @data: data buffer to read data into
+ * @count: size of buffer
+ * @offset: offset at which to read data
+ *
+ */
+
+static ssize_t
+v9fs_read(struct file *filp, char *buffer, size_t count, loff_t * offset)
+{
+ struct inode *inode = filp->f_dentry->d_inode;
+ struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
+ struct v9fs_fid *v9f = filp->private_data;
+ struct v9fs_fcall *fcall = NULL;
+ int fid = v9f->fid;
+ int rsize = 0;
+ int result = 0;
+ int total = 0;
+
+ dprintk(DEBUG_VFS, "\n");
+
+ rsize = v9ses->maxdata - V9FS_IOHDRSZ;
+ if (v9f->iounit != 0 && rsize > v9f->iounit)
+ rsize = v9f->iounit;
+
+ do {
+ if (count < rsize)
+ rsize = count;
+
+ result = v9fs_t_read(v9ses, fid, *offset, rsize, &fcall);
+
+ if (result < 0) {
+ printk(KERN_ERR "9P2000: v9fs_t_read returned %d\n",
+ result);
+
+ kfree(fcall);
+ return total;
+ } else
+ *offset += result;
+
+ /* XXX - extra copy */
+ memcpy(buffer, fcall->params.rread.data, result);
+ count -= result;
+ buffer += result;
+ total += result;
+
+ kfree(fcall);
+
+ if (result < rsize)
+ break;
+ } while (count);
+
+ return total;
+}
+
+/**
+ * v9fs_file_read - read from a file
+ * @filep: file pointer to read
+ * @data: 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 * data, size_t count,
+ loff_t * offset)
+{
+ int retval = -1;
+ int ret = 0;
+ char *buffer;
+
+ buffer = kmalloc(count, GFP_KERNEL);
+ if (!buffer)
+ return -ENOMEM;
+
+ retval = v9fs_read(filp, buffer, count, offset);
+ if (retval > 0) {
+ if ((ret = copy_to_user(data, buffer, retval)) != 0) {
+ dprintk(DEBUG_ERROR, "Problem copying to user %d\n",
+ ret);
+ retval = ret;
+ }
+ }
+
+ kfree(buffer);
+
+ return retval;
+}
+
+/**
+ * v9fs_write - write to a file
+ * @filep: 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_write(struct file *filp, char *buffer, size_t count, loff_t * offset)
+{
+ struct inode *inode = filp->f_dentry->d_inode;
+ struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
+ struct v9fs_fid *v9fid = filp->private_data;
+ struct v9fs_fcall *fcall;
+ int fid = v9fid->fid;
+ int result = -EIO;
+ int rsize = 0;
+ int total = 0;
+
+ dprintk(DEBUG_VFS, "data %p count %d offset %x\n", buffer, (int)count,
+ (int)*offset);
+ rsize = v9ses->maxdata - V9FS_IOHDRSZ;
+ if (v9fid->iounit != 0 && rsize > v9fid->iounit)
+ rsize = v9fid->iounit;
+
+ dump_data(buffer, count);
+
+ do {
+ if (count < rsize)
+ rsize = count;
+
+ result =
+ v9fs_t_write(v9ses, fid, *offset, rsize, buffer, &fcall);
+ if (result < 0) {
+ eprintk(KERN_ERR, "error while writing: %s(%d)\n",
+ FCALL_ERROR(fcall), result);
+ kfree(fcall);
+ return result;
+ } else
+ *offset += result;
+
+ kfree(fcall);
+
+ if (result != rsize) {
+ eprintk(KERN_ERR,
+ "short write: v9fs_t_write returned %d\n",
+ result);
+ break;
+ }
+
+ count -= result;
+ buffer += result;
+ total += result;
+ } while (count);
+
+ return total;
+}
+
+/**
+ * v9fs_file_write - write to a file
+ * @filep: 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 ret = -1;
+ char *buffer;
+
+ buffer = kmalloc(count, GFP_KERNEL);
+ if (buffer == NULL)
+ return -ENOMEM;
+
+ ret = copy_from_user(buffer, data, count);
+ if (ret) {
+ dprintk(DEBUG_ERROR, "Problem copying from user\n");
+ ret = -EFAULT;
+ } else {
+ ret = v9fs_write(filp, buffer, count, offset);
+ }
+
+ kfree(buffer);
+
+ return ret;
+}
+
+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,
+};
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