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OpenCloudOS-Kernel/fs/9p/vfs_inode.c

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/*
* linux/fs/9p/vfs_inode.c
*
* This file contains vfs inode 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/pagemap.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/inet.h>
#include <linux/namei.h>
#include <linux/idr.h>
#include <linux/sched.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include "v9fs.h"
#include "v9fs_vfs.h"
#include "fid.h"
static const struct inode_operations v9fs_dir_inode_operations;
static const struct inode_operations v9fs_dir_inode_operations_ext;
static const struct inode_operations v9fs_file_inode_operations;
static const struct inode_operations v9fs_symlink_inode_operations;
/**
* unixmode2p9mode - convert unix mode bits to plan 9
* @v9ses: v9fs session information
* @mode: mode to convert
*
*/
static int unixmode2p9mode(struct v9fs_session_info *v9ses, int mode)
{
int res;
res = mode & 0777;
if (S_ISDIR(mode))
res |= P9_DMDIR;
if (v9fs_extended(v9ses)) {
if (S_ISLNK(mode))
res |= P9_DMSYMLINK;
if (v9ses->nodev == 0) {
if (S_ISSOCK(mode))
res |= P9_DMSOCKET;
if (S_ISFIFO(mode))
res |= P9_DMNAMEDPIPE;
if (S_ISBLK(mode))
res |= P9_DMDEVICE;
if (S_ISCHR(mode))
res |= P9_DMDEVICE;
}
if ((mode & S_ISUID) == S_ISUID)
res |= P9_DMSETUID;
if ((mode & S_ISGID) == S_ISGID)
res |= P9_DMSETGID;
if ((mode & S_ISVTX) == S_ISVTX)
res |= P9_DMSETVTX;
if ((mode & P9_DMLINK))
res |= P9_DMLINK;
}
return res;
}
/**
* p9mode2unixmode- convert plan9 mode bits to unix mode bits
* @v9ses: v9fs session information
* @mode: mode to convert
*
*/
static int p9mode2unixmode(struct v9fs_session_info *v9ses, int mode)
{
int res;
res = mode & 0777;
if ((mode & P9_DMDIR) == P9_DMDIR)
res |= S_IFDIR;
else if ((mode & P9_DMSYMLINK) && (v9fs_extended(v9ses)))
res |= S_IFLNK;
else if ((mode & P9_DMSOCKET) && (v9fs_extended(v9ses))
&& (v9ses->nodev == 0))
res |= S_IFSOCK;
else if ((mode & P9_DMNAMEDPIPE) && (v9fs_extended(v9ses))
&& (v9ses->nodev == 0))
res |= S_IFIFO;
else if ((mode & P9_DMDEVICE) && (v9fs_extended(v9ses))
&& (v9ses->nodev == 0))
res |= S_IFBLK;
else
res |= S_IFREG;
if (v9fs_extended(v9ses)) {
if ((mode & P9_DMSETUID) == P9_DMSETUID)
res |= S_ISUID;
if ((mode & P9_DMSETGID) == P9_DMSETGID)
res |= S_ISGID;
if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
res |= S_ISVTX;
}
return res;
}
/**
* v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
* @uflags: flags to convert
* @extended: if .u extensions are active
*/
int v9fs_uflags2omode(int uflags, int extended)
{
int ret;
ret = 0;
switch (uflags&3) {
default:
case O_RDONLY:
ret = P9_OREAD;
break;
case O_WRONLY:
ret = P9_OWRITE;
break;
case O_RDWR:
ret = P9_ORDWR;
break;
}
if (uflags & O_TRUNC)
ret |= P9_OTRUNC;
if (extended) {
if (uflags & O_EXCL)
ret |= P9_OEXCL;
if (uflags & O_APPEND)
ret |= P9_OAPPEND;
}
return ret;
}
/**
* v9fs_blank_wstat - helper function to setup a 9P stat structure
* @v9ses: 9P session info (for determining extended mode)
* @wstat: structure to initialize
*
*/
static void
v9fs_blank_wstat(struct p9_wstat *wstat)
{
wstat->type = ~0;
wstat->dev = ~0;
wstat->qid.type = ~0;
wstat->qid.version = ~0;
*((long long *)&wstat->qid.path) = ~0;
wstat->mode = ~0;
wstat->atime = ~0;
wstat->mtime = ~0;
wstat->length = ~0;
wstat->name = NULL;
wstat->uid = NULL;
wstat->gid = NULL;
wstat->muid = NULL;
wstat->n_uid = ~0;
wstat->n_gid = ~0;
wstat->n_muid = ~0;
wstat->extension = NULL;
}
/**
* v9fs_get_inode - helper function to setup an inode
* @sb: superblock
* @mode: mode to setup inode with
*
*/
struct inode *v9fs_get_inode(struct super_block *sb, int mode)
{
struct inode *inode;
struct v9fs_session_info *v9ses = sb->s_fs_info;
P9_DPRINTK(P9_DEBUG_VFS, "super block: %p mode: %o\n", sb, mode);
inode = new_inode(sb);
if (inode) {
inode->i_mode = mode;
inode->i_uid = current_fsuid();
inode->i_gid = current_fsgid();
inode->i_blocks = 0;
inode->i_rdev = 0;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
inode->i_mapping->a_ops = &v9fs_addr_operations;
switch (mode & S_IFMT) {
case S_IFIFO:
case S_IFBLK:
case S_IFCHR:
case S_IFSOCK:
if (!v9fs_extended(v9ses)) {
P9_DPRINTK(P9_DEBUG_ERROR,
"special files without extended mode\n");
return ERR_PTR(-EINVAL);
}
init_special_inode(inode, inode->i_mode,
inode->i_rdev);
break;
case S_IFREG:
inode->i_op = &v9fs_file_inode_operations;
inode->i_fop = &v9fs_file_operations;
break;
case S_IFLNK:
if (!v9fs_extended(v9ses)) {
P9_DPRINTK(P9_DEBUG_ERROR,
"extended modes used w/o 9P2000.u\n");
return ERR_PTR(-EINVAL);
}
inode->i_op = &v9fs_symlink_inode_operations;
break;
case S_IFDIR:
inc_nlink(inode);
if (v9fs_extended(v9ses))
inode->i_op = &v9fs_dir_inode_operations_ext;
else
inode->i_op = &v9fs_dir_inode_operations;
inode->i_fop = &v9fs_dir_operations;
break;
default:
P9_DPRINTK(P9_DEBUG_ERROR,
"BAD mode 0x%x S_IFMT 0x%x\n",
mode, mode & S_IFMT);
return ERR_PTR(-EINVAL);
}
} else {
P9_EPRINTK(KERN_WARNING, "Problem allocating inode\n");
return ERR_PTR(-ENOMEM);
}
return inode;
}
/*
static struct v9fs_fid*
v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
{
int err;
int nfid;
struct v9fs_fid *ret;
struct v9fs_fcall *fcall;
nfid = v9fs_get_idpool(&v9ses->fidpool);
if (nfid < 0) {
eprintk(KERN_WARNING, "no free fids available\n");
return ERR_PTR(-ENOSPC);
}
err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
&fcall);
if (err < 0) {
if (fcall && fcall->id == RWALK)
goto clunk_fid;
PRINT_FCALL_ERROR("walk error", fcall);
v9fs_put_idpool(nfid, &v9ses->fidpool);
goto error;
}
kfree(fcall);
fcall = NULL;
ret = v9fs_fid_create(v9ses, nfid);
if (!ret) {
err = -ENOMEM;
goto clunk_fid;
}
err = v9fs_fid_insert(ret, dentry);
if (err < 0) {
v9fs_fid_destroy(ret);
goto clunk_fid;
}
return ret;
clunk_fid:
v9fs_t_clunk(v9ses, nfid);
error:
kfree(fcall);
return ERR_PTR(err);
}
*/
/**
* v9fs_inode_from_fid - populate an inode by issuing a attribute request
* @v9ses: session information
* @fid: fid to issue attribute request for
* @sb: superblock on which to create inode
*
*/
static struct inode *
v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
struct super_block *sb)
{
int err, umode;
struct inode *ret;
struct p9_wstat *st;
ret = NULL;
st = p9_client_stat(fid);
if (IS_ERR(st)) {
err = PTR_ERR(st);
st = NULL;
goto error;
}
umode = p9mode2unixmode(v9ses, st->mode);
ret = v9fs_get_inode(sb, umode);
if (IS_ERR(ret)) {
err = PTR_ERR(ret);
ret = NULL;
goto error;
}
v9fs_stat2inode(st, ret, sb);
ret->i_ino = v9fs_qid2ino(&st->qid);
kfree(st);
return ret;
error:
kfree(st);
if (ret)
iput(ret);
return ERR_PTR(err);
}
/**
* v9fs_remove - helper function to remove files and directories
* @dir: directory inode that is being deleted
* @file: dentry that is being deleted
* @rmdir: removing a directory
*
*/
static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
{
struct inode *file_inode;
struct v9fs_session_info *v9ses;
struct p9_fid *v9fid;
P9_DPRINTK(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %d\n", dir, file,
rmdir);
file_inode = file->d_inode;
v9ses = v9fs_inode2v9ses(file_inode);
v9fid = v9fs_fid_clone(file);
if (IS_ERR(v9fid))
return PTR_ERR(v9fid);
return p9_client_remove(v9fid);
}
static int
v9fs_open_created(struct inode *inode, struct file *file)
{
return 0;
}
/**
* v9fs_create - Create a file
* @v9ses: session information
* @dir: directory that dentry is being created in
* @dentry: dentry that is being created
* @perm: create permissions
* @mode: open mode
* @extension: 9p2000.u extension string to support devices, etc.
*
*/
static struct p9_fid *
v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
struct dentry *dentry, char *extension, u32 perm, u8 mode)
{
int err;
char *name;
struct p9_fid *dfid, *ofid, *fid;
struct inode *inode;
P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
err = 0;
ofid = NULL;
fid = NULL;
name = (char *) dentry->d_name.name;
dfid = v9fs_fid_clone(dentry->d_parent);
if (IS_ERR(dfid)) {
err = PTR_ERR(dfid);
P9_DPRINTK(P9_DEBUG_VFS, "fid clone failed %d\n", err);
dfid = NULL;
goto error;
}
/* clone a fid to use for creation */
ofid = p9_client_walk(dfid, 0, NULL, 1);
if (IS_ERR(ofid)) {
err = PTR_ERR(ofid);
P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
ofid = NULL;
goto error;
}
err = p9_client_fcreate(ofid, name, perm, mode, extension);
if (err < 0) {
P9_DPRINTK(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
goto error;
}
/* now walk from the parent so we can get unopened fid */
fid = p9_client_walk(dfid, 1, &name, 0);
if (IS_ERR(fid)) {
err = PTR_ERR(fid);
P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
fid = NULL;
goto error;
} else
dfid = NULL;
/* instantiate inode and assign the unopened fid to the dentry */
inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
P9_DPRINTK(P9_DEBUG_VFS, "inode creation failed %d\n", err);
goto error;
}
if (v9ses->cache)
dentry->d_op = &v9fs_cached_dentry_operations;
else
dentry->d_op = &v9fs_dentry_operations;
d_instantiate(dentry, inode);
v9fs_fid_add(dentry, fid);
return ofid;
error:
if (dfid)
p9_client_clunk(dfid);
if (ofid)
p9_client_clunk(ofid);
if (fid)
p9_client_clunk(fid);
return ERR_PTR(err);
}
/**
* v9fs_vfs_create - VFS hook to create files
* @dir: directory inode that is being created
* @dentry: dentry that is being deleted
* @mode: create permissions
* @nd: path information
*
*/
static int
v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
struct nameidata *nd)
{
int err;
u32 perm;
int flags;
struct v9fs_session_info *v9ses;
struct p9_fid *fid;
struct file *filp;
err = 0;
fid = NULL;
v9ses = v9fs_inode2v9ses(dir);
perm = unixmode2p9mode(v9ses, mode);
if (nd && nd->flags & LOOKUP_OPEN)
flags = nd->intent.open.flags - 1;
else
flags = O_RDWR;
fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
v9fs_uflags2omode(flags, v9fs_extended(v9ses)));
if (IS_ERR(fid)) {
err = PTR_ERR(fid);
fid = NULL;
goto error;
}
/* if we are opening a file, assign the open fid to the file */
if (nd && nd->flags & LOOKUP_OPEN) {
filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created);
if (IS_ERR(filp)) {
err = PTR_ERR(filp);
goto error;
}
filp->private_data = fid;
} else
p9_client_clunk(fid);
return 0;
error:
if (fid)
p9_client_clunk(fid);
return err;
}
/**
* v9fs_vfs_mkdir - VFS mkdir hook to create a directory
* @dir: inode that is being unlinked
* @dentry: dentry that is being unlinked
* @mode: mode for new directory
*
*/
static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
int err;
u32 perm;
struct v9fs_session_info *v9ses;
struct p9_fid *fid;
P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
err = 0;
v9ses = v9fs_inode2v9ses(dir);
perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
if (IS_ERR(fid)) {
err = PTR_ERR(fid);
fid = NULL;
}
if (fid)
p9_client_clunk(fid);
return err;
}
/**
* v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
* @dir: inode that is being walked from
* @dentry: dentry that is being walked to?
* @nameidata: path data
*
*/
static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nameidata)
{
struct super_block *sb;
struct v9fs_session_info *v9ses;
struct p9_fid *dfid, *fid;
struct inode *inode;
char *name;
int result = 0;
P9_DPRINTK(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
dir, dentry->d_name.name, dentry, nameidata);
sb = dir->i_sb;
v9ses = v9fs_inode2v9ses(dir);
dfid = v9fs_fid_lookup(dentry->d_parent);
if (IS_ERR(dfid))
return ERR_CAST(dfid);
name = (char *) dentry->d_name.name;
fid = p9_client_walk(dfid, 1, &name, 1);
if (IS_ERR(fid)) {
result = PTR_ERR(fid);
if (result == -ENOENT) {
d_add(dentry, NULL);
return NULL;
}
return ERR_PTR(result);
}
inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
if (IS_ERR(inode)) {
result = PTR_ERR(inode);
inode = NULL;
goto error;
}
result = v9fs_fid_add(dentry, fid);
if (result < 0)
goto error;
if ((fid->qid.version) && (v9ses->cache))
dentry->d_op = &v9fs_cached_dentry_operations;
else
dentry->d_op = &v9fs_dentry_operations;
d_add(dentry, inode);
return NULL;
error:
p9_client_clunk(fid);
return ERR_PTR(result);
}
/**
* v9fs_vfs_unlink - VFS unlink hook to delete an inode
* @i: inode that is being unlinked
* @d: dentry that is being unlinked
*
*/
static int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
{
return v9fs_remove(i, d, 0);
}
/**
* v9fs_vfs_rmdir - VFS unlink hook to delete a directory
* @i: inode that is being unlinked
* @d: dentry that is being unlinked
*
*/
static int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
{
return v9fs_remove(i, d, 1);
}
/**
* v9fs_vfs_rename - VFS hook to rename an inode
* @old_dir: old dir inode
* @old_dentry: old dentry
* @new_dir: new dir inode
* @new_dentry: new dentry
*
*/
static int
v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
struct inode *old_inode;
struct v9fs_session_info *v9ses;
struct p9_fid *oldfid;
struct p9_fid *olddirfid;
struct p9_fid *newdirfid;
struct p9_wstat wstat;
int retval;
P9_DPRINTK(P9_DEBUG_VFS, "\n");
retval = 0;
old_inode = old_dentry->d_inode;
v9ses = v9fs_inode2v9ses(old_inode);
oldfid = v9fs_fid_lookup(old_dentry);
if (IS_ERR(oldfid))
return PTR_ERR(oldfid);
olddirfid = v9fs_fid_clone(old_dentry->d_parent);
if (IS_ERR(olddirfid)) {
retval = PTR_ERR(olddirfid);
goto done;
}
newdirfid = v9fs_fid_clone(new_dentry->d_parent);
if (IS_ERR(newdirfid)) {
retval = PTR_ERR(newdirfid);
goto clunk_olddir;
}
/* 9P can only handle file rename in the same directory */
if (memcmp(&olddirfid->qid, &newdirfid->qid, sizeof(newdirfid->qid))) {
P9_DPRINTK(P9_DEBUG_ERROR,
"old dir and new dir are different\n");
retval = -EXDEV;
goto clunk_newdir;
}
v9fs_blank_wstat(&wstat);
wstat.muid = v9ses->uname;
wstat.name = (char *) new_dentry->d_name.name;
retval = p9_client_wstat(oldfid, &wstat);
clunk_newdir:
p9_client_clunk(newdirfid);
clunk_olddir:
p9_client_clunk(olddirfid);
done:
return retval;
}
/**
* v9fs_vfs_getattr - retrieve file metadata
* @mnt: mount information
* @dentry: file to get attributes on
* @stat: metadata structure to populate
*
*/
static int
v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
struct kstat *stat)
{
int err;
struct v9fs_session_info *v9ses;
struct p9_fid *fid;
struct p9_wstat *st;
P9_DPRINTK(P9_DEBUG_VFS, "dentry: %p\n", dentry);
err = -EPERM;
v9ses = v9fs_inode2v9ses(dentry->d_inode);
if (v9ses->cache == CACHE_LOOSE)
return simple_getattr(mnt, dentry, stat);
fid = v9fs_fid_lookup(dentry);
if (IS_ERR(fid))
return PTR_ERR(fid);
st = p9_client_stat(fid);
if (IS_ERR(st))
return PTR_ERR(st);
v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
generic_fillattr(dentry->d_inode, stat);
kfree(st);
return 0;
}
/**
* v9fs_vfs_setattr - set file metadata
* @dentry: file whose metadata to set
* @iattr: metadata assignment structure
*
*/
static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
{
int retval;
struct v9fs_session_info *v9ses;
struct p9_fid *fid;
struct p9_wstat wstat;
P9_DPRINTK(P9_DEBUG_VFS, "\n");
retval = -EPERM;
v9ses = v9fs_inode2v9ses(dentry->d_inode);
fid = v9fs_fid_lookup(dentry);
if(IS_ERR(fid))
return PTR_ERR(fid);
v9fs_blank_wstat(&wstat);
if (iattr->ia_valid & ATTR_MODE)
wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
if (iattr->ia_valid & ATTR_MTIME)
wstat.mtime = iattr->ia_mtime.tv_sec;
if (iattr->ia_valid & ATTR_ATIME)
wstat.atime = iattr->ia_atime.tv_sec;
if (iattr->ia_valid & ATTR_SIZE)
wstat.length = iattr->ia_size;
if (v9fs_extended(v9ses)) {
if (iattr->ia_valid & ATTR_UID)
wstat.n_uid = iattr->ia_uid;
if (iattr->ia_valid & ATTR_GID)
wstat.n_gid = iattr->ia_gid;
}
retval = p9_client_wstat(fid, &wstat);
if (retval >= 0)
retval = inode_setattr(dentry->d_inode, iattr);
return retval;
}
/**
* v9fs_stat2inode - populate an inode structure with mistat info
* @stat: Plan 9 metadata (mistat) structure
* @inode: inode to populate
* @sb: superblock of filesystem
*
*/
void
v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
struct super_block *sb)
{
char ext[32];
struct v9fs_session_info *v9ses = sb->s_fs_info;
inode->i_nlink = 1;
inode->i_atime.tv_sec = stat->atime;
inode->i_mtime.tv_sec = stat->mtime;
inode->i_ctime.tv_sec = stat->mtime;
inode->i_uid = v9ses->dfltuid;
inode->i_gid = v9ses->dfltgid;
if (v9fs_extended(v9ses)) {
inode->i_uid = stat->n_uid;
inode->i_gid = stat->n_gid;
}
inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
char type = 0;
int major = -1;
int minor = -1;
strncpy(ext, stat->extension, sizeof(ext));
sscanf(ext, "%c %u %u", &type, &major, &minor);
switch (type) {
case 'c':
inode->i_mode &= ~S_IFBLK;
inode->i_mode |= S_IFCHR;
break;
case 'b':
break;
default:
P9_DPRINTK(P9_DEBUG_ERROR,
"Unknown special type %c %s\n", type,
stat->extension);
};
inode->i_rdev = MKDEV(major, minor);
init_special_inode(inode, inode->i_mode, inode->i_rdev);
} else
inode->i_rdev = 0;
inode->i_size = stat->length;
/* not real number of blocks, but 512 byte ones ... */
inode->i_blocks = (inode->i_size + 512 - 1) >> 9;
}
/**
* v9fs_qid2ino - convert qid into inode number
* @qid: qid to hash
*
* BUG: potential for inode number collisions?
*/
ino_t v9fs_qid2ino(struct p9_qid *qid)
{
u64 path = qid->path + 2;
ino_t i = 0;
if (sizeof(ino_t) == sizeof(path))
memcpy(&i, &path, sizeof(ino_t));
else
i = (ino_t) (path ^ (path >> 32));
return i;
}
/**
* v9fs_readlink - read a symlink's location (internal version)
* @dentry: dentry for symlink
* @buffer: buffer to load symlink location into
* @buflen: length of buffer
*
*/
static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
{
int retval;
struct v9fs_session_info *v9ses;
struct p9_fid *fid;
struct p9_wstat *st;
P9_DPRINTK(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
retval = -EPERM;
v9ses = v9fs_inode2v9ses(dentry->d_inode);
fid = v9fs_fid_lookup(dentry);
if (IS_ERR(fid))
return PTR_ERR(fid);
if (!v9fs_extended(v9ses))
return -EBADF;
st = p9_client_stat(fid);
if (IS_ERR(st))
return PTR_ERR(st);
if (!(st->mode & P9_DMSYMLINK)) {
retval = -EINVAL;
goto done;
}
/* copy extension buffer into buffer */
strncpy(buffer, st->extension, buflen);
P9_DPRINTK(P9_DEBUG_VFS,
"%s -> %s (%s)\n", dentry->d_name.name, st->extension, buffer);
retval = buflen;
done:
kfree(st);
return retval;
}
/**
* v9fs_vfs_readlink - read a symlink's location
* @dentry: dentry for symlink
* @buffer: buffer to load symlink location into
* @buflen: length of buffer
*
*/
static int v9fs_vfs_readlink(struct dentry *dentry, char __user * buffer,
int buflen)
{
int retval;
int ret;
char *link = __getname();
if (unlikely(!link))
return -ENOMEM;
if (buflen > PATH_MAX)
buflen = PATH_MAX;
P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_name.name,
dentry);
retval = v9fs_readlink(dentry, link, buflen);
if (retval > 0) {
if ((ret = copy_to_user(buffer, link, retval)) != 0) {
P9_DPRINTK(P9_DEBUG_ERROR,
"problem copying to user: %d\n", ret);
retval = ret;
}
}
__putname(link);
return retval;
}
/**
* v9fs_vfs_follow_link - follow a symlink path
* @dentry: dentry for symlink
* @nd: nameidata
*
*/
static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
{
int len = 0;
char *link = __getname();
P9_DPRINTK(P9_DEBUG_VFS, "%s n", dentry->d_name.name);
if (!link)
link = ERR_PTR(-ENOMEM);
else {
len = v9fs_readlink(dentry, link, PATH_MAX);
if (len < 0) {
__putname(link);
link = ERR_PTR(len);
} else
link[len] = 0;
}
nd_set_link(nd, link);
return NULL;
}
/**
* v9fs_vfs_put_link - release a symlink path
* @dentry: dentry for symlink
* @nd: nameidata
* @p: unused
*
*/
static void
v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
{
char *s = nd_get_link(nd);
P9_DPRINTK(P9_DEBUG_VFS, " %s %s\n", dentry->d_name.name,
IS_ERR(s) ? "<error>" : s);
if (!IS_ERR(s))
__putname(s);
}
/**
* v9fs_vfs_mkspecial - create a special file
* @dir: inode to create special file in
* @dentry: dentry to create
* @mode: mode to create special file
* @extension: 9p2000.u format extension string representing special file
*
*/
static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
int mode, const char *extension)
{
u32 perm;
struct v9fs_session_info *v9ses;
struct p9_fid *fid;
v9ses = v9fs_inode2v9ses(dir);
if (!v9fs_extended(v9ses)) {
P9_DPRINTK(P9_DEBUG_ERROR, "not extended\n");
return -EPERM;
}
perm = unixmode2p9mode(v9ses, mode);
fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
P9_OREAD);
if (IS_ERR(fid))
return PTR_ERR(fid);
p9_client_clunk(fid);
return 0;
}
/**
* v9fs_vfs_symlink - helper function to create symlinks
* @dir: directory inode containing symlink
* @dentry: dentry for symlink
* @symname: symlink data
*
* See Also: 9P2000.u RFC for more information
*
*/
static int
v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
{
P9_DPRINTK(P9_DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino,
dentry->d_name.name, symname);
return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
}
/**
* v9fs_vfs_link - create a hardlink
* @old_dentry: dentry for file to link to
* @dir: inode destination for new link
* @dentry: dentry for link
*
*/
static int
v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *dentry)
{
int retval;
struct p9_fid *oldfid;
char *name;
P9_DPRINTK(P9_DEBUG_VFS,
" %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
old_dentry->d_name.name);
oldfid = v9fs_fid_clone(old_dentry);
if (IS_ERR(oldfid))
return PTR_ERR(oldfid);
name = __getname();
if (unlikely(!name)) {
retval = -ENOMEM;
goto clunk_fid;
}
sprintf(name, "%d\n", oldfid->fid);
retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
__putname(name);
clunk_fid:
p9_client_clunk(oldfid);
return retval;
}
/**
* v9fs_vfs_mknod - create a special file
* @dir: inode destination for new link
* @dentry: dentry for file
* @mode: mode for creation
* @rdev: device associated with special file
*
*/
static int
v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
{
int retval;
char *name;
P9_DPRINTK(P9_DEBUG_VFS,
" %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
if (!new_valid_dev(rdev))
return -EINVAL;
name = __getname();
if (!name)
return -ENOMEM;
/* build extension */
if (S_ISBLK(mode))
sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
else if (S_ISCHR(mode))
sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
else if (S_ISFIFO(mode))
*name = 0;
else {
__putname(name);
return -EINVAL;
}
retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
__putname(name);
return retval;
}
static const struct inode_operations v9fs_dir_inode_operations_ext = {
.create = v9fs_vfs_create,
.lookup = v9fs_vfs_lookup,
.symlink = v9fs_vfs_symlink,
.link = v9fs_vfs_link,
.unlink = v9fs_vfs_unlink,
.mkdir = v9fs_vfs_mkdir,
.rmdir = v9fs_vfs_rmdir,
.mknod = v9fs_vfs_mknod,
.rename = v9fs_vfs_rename,
.readlink = v9fs_vfs_readlink,
.getattr = v9fs_vfs_getattr,
.setattr = v9fs_vfs_setattr,
};
static const struct inode_operations v9fs_dir_inode_operations = {
.create = v9fs_vfs_create,
.lookup = v9fs_vfs_lookup,
.unlink = v9fs_vfs_unlink,
.mkdir = v9fs_vfs_mkdir,
.rmdir = v9fs_vfs_rmdir,
.mknod = v9fs_vfs_mknod,
.rename = v9fs_vfs_rename,
.getattr = v9fs_vfs_getattr,
.setattr = v9fs_vfs_setattr,
};
static const struct inode_operations v9fs_file_inode_operations = {
.getattr = v9fs_vfs_getattr,
.setattr = v9fs_vfs_setattr,
};
static const struct inode_operations v9fs_symlink_inode_operations = {
.readlink = v9fs_vfs_readlink,
.follow_link = v9fs_vfs_follow_link,
.put_link = v9fs_vfs_put_link,
.getattr = v9fs_vfs_getattr,
.setattr = v9fs_vfs_setattr,
};
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