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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/fs/9p/vfs_inode.c

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34 KiB
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
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#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 <linux/slab.h>
#include <linux/xattr.h>
#include <linux/posix_acl.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include "v9fs.h"
#include "v9fs_vfs.h"
#include "fid.h"
#include "cache.h"
#include "xattr.h"
#include "acl.h"
static const struct inode_operations v9fs_dir_inode_operations;
static const struct inode_operations v9fs_dir_inode_operations_dotu;
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 u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode)
{
int res;
res = mode & 0777;
if (S_ISDIR(mode))
res |= P9_DMDIR;
if (v9fs_proto_dotu(v9ses)) {
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;
}
return res;
}
/**
* p9mode2perm- convert plan9 mode bits to unix permission bits
* @v9ses: v9fs session information
* @stat: p9_wstat from which mode need to be derived
*
*/
static int p9mode2perm(struct v9fs_session_info *v9ses,
struct p9_wstat *stat)
{
int res;
int mode = stat->mode;
res = mode & S_IALLUGO;
if (v9fs_proto_dotu(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;
}
/**
* p9mode2unixmode- convert plan9 mode bits to unix mode bits
* @v9ses: v9fs session information
* @stat: p9_wstat from which mode need to be derived
* @rdev: major number, minor number in case of device files.
*
*/
static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
struct p9_wstat *stat, dev_t *rdev)
{
int res;
u32 mode = stat->mode;
*rdev = 0;
res = p9mode2perm(v9ses, stat);
if ((mode & P9_DMDIR) == P9_DMDIR)
res |= S_IFDIR;
else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
res |= S_IFLNK;
else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
&& (v9ses->nodev == 0))
res |= S_IFSOCK;
else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
&& (v9ses->nodev == 0))
res |= S_IFIFO;
else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
&& (v9ses->nodev == 0)) {
char type = 0, ext[32];
int major = -1, minor = -1;
strlcpy(ext, stat->extension, sizeof(ext));
sscanf(ext, "%c %i %i", &type, &major, &minor);
switch (type) {
case 'c':
res |= S_IFCHR;
break;
case 'b':
res |= S_IFBLK;
break;
default:
p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n",
type, stat->extension);
};
*rdev = MKDEV(major, minor);
} else
res |= S_IFREG;
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 (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
* @wstat: structure to initialize
*
*/
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 = INVALID_UID;
wstat->n_gid = INVALID_GID;
wstat->n_muid = INVALID_UID;
wstat->extension = NULL;
}
/**
* v9fs_alloc_inode - helper function to allocate an inode
*
*/
struct inode *v9fs_alloc_inode(struct super_block *sb)
{
struct v9fs_inode *v9inode;
v9inode = (struct v9fs_inode *)kmem_cache_alloc(v9fs_inode_cache,
GFP_KERNEL);
if (!v9inode)
return NULL;
#ifdef CONFIG_9P_FSCACHE
v9inode->fscache = NULL;
mutex_init(&v9inode->fscache_lock);
#endif
v9inode->writeback_fid = NULL;
v9inode->cache_validity = 0;
mutex_init(&v9inode->v_mutex);
return &v9inode->vfs_inode;
}
/**
* v9fs_destroy_inode - destroy an inode
*
*/
static void v9fs_i_callback(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
}
void v9fs_destroy_inode(struct inode *inode)
{
call_rcu(&inode->i_rcu, v9fs_i_callback);
}
int v9fs_init_inode(struct v9fs_session_info *v9ses,
struct inode *inode, umode_t mode, dev_t rdev)
{
int err = 0;
inode_init_owner(inode, NULL, mode);
inode->i_blocks = 0;
inode->i_rdev = rdev;
inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
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_proto_dotl(v9ses)) {
inode->i_op = &v9fs_file_inode_operations_dotl;
} else if (v9fs_proto_dotu(v9ses)) {
inode->i_op = &v9fs_file_inode_operations;
} else {
p9_debug(P9_DEBUG_ERROR,
"special files without extended mode\n");
err = -EINVAL;
goto error;
}
init_special_inode(inode, inode->i_mode, inode->i_rdev);
break;
case S_IFREG:
if (v9fs_proto_dotl(v9ses)) {
inode->i_op = &v9fs_file_inode_operations_dotl;
if (v9ses->cache == CACHE_LOOSE ||
v9ses->cache == CACHE_FSCACHE)
inode->i_fop =
&v9fs_cached_file_operations_dotl;
else if (v9ses->cache == CACHE_MMAP)
inode->i_fop = &v9fs_mmap_file_operations_dotl;
else
inode->i_fop = &v9fs_file_operations_dotl;
} else {
inode->i_op = &v9fs_file_inode_operations;
if (v9ses->cache == CACHE_LOOSE ||
v9ses->cache == CACHE_FSCACHE)
inode->i_fop =
&v9fs_cached_file_operations;
else if (v9ses->cache == CACHE_MMAP)
inode->i_fop = &v9fs_mmap_file_operations;
else
inode->i_fop = &v9fs_file_operations;
}
break;
case S_IFLNK:
if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
p9_debug(P9_DEBUG_ERROR,
"extended modes used with legacy protocol\n");
err = -EINVAL;
goto error;
}
if (v9fs_proto_dotl(v9ses))
inode->i_op = &v9fs_symlink_inode_operations_dotl;
else
inode->i_op = &v9fs_symlink_inode_operations;
break;
case S_IFDIR:
inc_nlink(inode);
if (v9fs_proto_dotl(v9ses))
inode->i_op = &v9fs_dir_inode_operations_dotl;
else if (v9fs_proto_dotu(v9ses))
inode->i_op = &v9fs_dir_inode_operations_dotu;
else
inode->i_op = &v9fs_dir_inode_operations;
if (v9fs_proto_dotl(v9ses))
inode->i_fop = &v9fs_dir_operations_dotl;
else
inode->i_fop = &v9fs_dir_operations;
break;
default:
p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
mode, mode & S_IFMT);
err = -EINVAL;
goto error;
}
error:
return err;
}
/**
* 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, umode_t mode, dev_t rdev)
{
int err;
struct inode *inode;
struct v9fs_session_info *v9ses = sb->s_fs_info;
p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
inode = new_inode(sb);
if (!inode) {
pr_warn("%s (%d): Problem allocating inode\n",
__func__, task_pid_nr(current));
return ERR_PTR(-ENOMEM);
}
err = v9fs_init_inode(v9ses, inode, mode, rdev);
if (err) {
iput(inode);
return ERR_PTR(err);
}
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_clear_inode - release an inode
* @inode: inode to release
*
*/
void v9fs_evict_inode(struct inode *inode)
{
struct v9fs_inode *v9inode = V9FS_I(inode);
truncate_inode_pages_final(&inode->i_data);
clear_inode(inode);
filemap_fdatawrite(&inode->i_data);
v9fs_cache_inode_put_cookie(inode);
/* clunk the fid stashed in writeback_fid */
if (v9inode->writeback_fid) {
p9_client_clunk(v9inode->writeback_fid);
v9inode->writeback_fid = NULL;
}
}
static int v9fs_test_inode(struct inode *inode, void *data)
{
int umode;
dev_t rdev;
struct v9fs_inode *v9inode = V9FS_I(inode);
struct p9_wstat *st = (struct p9_wstat *)data;
struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
umode = p9mode2unixmode(v9ses, st, &rdev);
/* don't match inode of different type */
if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
return 0;
/* compare qid details */
if (memcmp(&v9inode->qid.version,
&st->qid.version, sizeof(v9inode->qid.version)))
return 0;
if (v9inode->qid.type != st->qid.type)
return 0;
if (v9inode->qid.path != st->qid.path)
return 0;
return 1;
}
static int v9fs_test_new_inode(struct inode *inode, void *data)
{
return 0;
}
static int v9fs_set_inode(struct inode *inode, void *data)
{
struct v9fs_inode *v9inode = V9FS_I(inode);
struct p9_wstat *st = (struct p9_wstat *)data;
memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
return 0;
}
static struct inode *v9fs_qid_iget(struct super_block *sb,
struct p9_qid *qid,
struct p9_wstat *st,
int new)
{
dev_t rdev;
int retval;
umode_t umode;
unsigned long i_ino;
struct inode *inode;
struct v9fs_session_info *v9ses = sb->s_fs_info;
int (*test)(struct inode *, void *);
if (new)
test = v9fs_test_new_inode;
else
test = v9fs_test_inode;
i_ino = v9fs_qid2ino(qid);
inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
if (!inode)
return ERR_PTR(-ENOMEM);
if (!(inode->i_state & I_NEW))
return inode;
/*
* initialize the inode with the stat info
* FIXME!! we may need support for stale inodes
* later.
*/
inode->i_ino = i_ino;
umode = p9mode2unixmode(v9ses, st, &rdev);
retval = v9fs_init_inode(v9ses, inode, umode, rdev);
if (retval)
goto error;
v9fs_stat2inode(st, inode, sb);
v9fs_cache_inode_get_cookie(inode);
unlock_new_inode(inode);
return inode;
error:
iget_failed(inode);
return ERR_PTR(retval);
}
struct inode *
v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
struct super_block *sb, int new)
{
struct p9_wstat *st;
struct inode *inode = NULL;
st = p9_client_stat(fid);
if (IS_ERR(st))
return ERR_CAST(st);
inode = v9fs_qid_iget(sb, &st->qid, st, new);
p9stat_free(st);
kfree(st);
return inode;
}
/**
* v9fs_at_to_dotl_flags- convert Linux specific AT flags to
* plan 9 AT flag.
* @flags: flags to convert
*/
static int v9fs_at_to_dotl_flags(int flags)
{
int rflags = 0;
if (flags & AT_REMOVEDIR)
rflags |= P9_DOTL_AT_REMOVEDIR;
return rflags;
}
/**
* v9fs_dec_count - helper functon to drop i_nlink.
*
* If a directory had nlink <= 2 (including . and ..), then we should not drop
* the link count, which indicates the underlying exported fs doesn't maintain
* nlink accurately. e.g.
* - overlayfs sets nlink to 1 for merged dir
* - ext4 (with dir_nlink feature enabled) sets nlink to 1 if a dir has more
* than EXT4_LINK_MAX (65000) links.
*
* @inode: inode whose nlink is being dropped
*/
static void v9fs_dec_count(struct inode *inode)
{
if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
drop_nlink(inode);
}
/**
* v9fs_remove - helper function to remove files and directories
* @dir: directory inode that is being deleted
* @dentry: dentry that is being deleted
* @flags: removing a directory
*
*/
static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
{
struct inode *inode;
int retval = -EOPNOTSUPP;
struct p9_fid *v9fid, *dfid;
struct v9fs_session_info *v9ses;
p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
dir, dentry, flags);
v9ses = v9fs_inode2v9ses(dir);
inode = d_inode(dentry);
dfid = v9fs_parent_fid(dentry);
if (IS_ERR(dfid)) {
retval = PTR_ERR(dfid);
p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
return retval;
}
if (v9fs_proto_dotl(v9ses))
retval = p9_client_unlinkat(dfid, dentry->d_name.name,
v9fs_at_to_dotl_flags(flags));
if (retval == -EOPNOTSUPP) {
/* Try the one based on path */
v9fid = v9fs_fid_clone(dentry);
if (IS_ERR(v9fid))
return PTR_ERR(v9fid);
retval = p9_client_remove(v9fid);
}
if (!retval) {
/*
* directories on unlink should have zero
* link count
*/
if (flags & AT_REMOVEDIR) {
clear_nlink(inode);
v9fs_dec_count(dir);
} else
v9fs_dec_count(inode);
v9fs_invalidate_inode_attr(inode);
v9fs_invalidate_inode_attr(dir);
}
return retval;
}
/**
* v9fs_create - Create a file
* @v9ses: session information
* @dir: directory that dentry is being created in
* @dentry: dentry that is being created
* @extension: 9p2000.u extension string to support devices, etc.
* @perm: create permissions
* @mode: open mode
*
*/
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;
const unsigned char *name;
struct p9_fid *dfid, *ofid, *fid;
struct inode *inode;
p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
err = 0;
ofid = NULL;
fid = NULL;
name = dentry->d_name.name;
dfid = v9fs_parent_fid(dentry);
if (IS_ERR(dfid)) {
err = PTR_ERR(dfid);
p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
return ERR_PTR(err);
}
/* clone a fid to use for creation */
ofid = clone_fid(dfid);
if (IS_ERR(ofid)) {
err = PTR_ERR(ofid);
p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
return ERR_PTR(err);
}
err = p9_client_fcreate(ofid, name, perm, mode, extension);
if (err < 0) {
p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
goto error;
}
if (!(perm & P9_DMLINK)) {
/* now walk from the parent so we can get unopened fid */
fid = p9_client_walk(dfid, 1, &name, 1);
if (IS_ERR(fid)) {
err = PTR_ERR(fid);
p9_debug(P9_DEBUG_VFS,
"p9_client_walk failed %d\n", err);
fid = NULL;
goto error;
}
/*
* instantiate inode and assign the unopened fid to the dentry
*/
inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
p9_debug(P9_DEBUG_VFS,
"inode creation failed %d\n", err);
goto error;
}
v9fs_fid_add(dentry, fid);
d_instantiate(dentry, inode);
}
return ofid;
error:
if (ofid)
p9_client_clunk(ofid);
if (fid)
p9_client_clunk(fid);
return ERR_PTR(err);
}
/**
* v9fs_vfs_create - VFS hook to create a regular file
*
* open(.., O_CREAT) is handled in v9fs_vfs_atomic_open(). This is only called
* for mknod(2).
*
* @dir: directory inode that is being created
* @dentry: dentry that is being deleted
* @mode: create permissions
*
*/
static int
v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
bool excl)
{
struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
u32 perm = unixmode2p9mode(v9ses, mode);
struct p9_fid *fid;
/* P9_OEXCL? */
fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
if (IS_ERR(fid))
return PTR_ERR(fid);
v9fs_invalidate_inode_attr(dir);
p9_client_clunk(fid);
return 0;
}
/**
* 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, umode_t mode)
{
int err;
u32 perm;
struct p9_fid *fid;
struct v9fs_session_info *v9ses;
p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
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;
} else {
inc_nlink(dir);
v9fs_invalidate_inode_attr(dir);
}
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?
* @flags: lookup flags (unused)
*
*/
struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
struct dentry *res;
struct v9fs_session_info *v9ses;
struct p9_fid *dfid, *fid;
struct inode *inode;
const unsigned char *name;
p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n",
dir, dentry, dentry, flags);
if (dentry->d_name.len > NAME_MAX)
return ERR_PTR(-ENAMETOOLONG);
v9ses = v9fs_inode2v9ses(dir);
/* We can walk d_parent because we hold the dir->i_mutex */
dfid = v9fs_parent_fid(dentry);
if (IS_ERR(dfid))
return ERR_CAST(dfid);
/*
* Make sure we don't use a wrong inode due to parallel
* unlink. For cached mode create calls request for new
* inode. But with cache disabled, lookup should do this.
*/
name = dentry->d_name.name;
fid = p9_client_walk(dfid, 1, &name, 1);
if (fid == ERR_PTR(-ENOENT))
inode = NULL;
else if (IS_ERR(fid))
inode = ERR_CAST(fid);
else if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
else
inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
/*
* If we had a rename on the server and a parallel lookup
* for the new name, then make sure we instantiate with
* the new name. ie look up for a/b, while on server somebody
* moved b under k and client parallely did a lookup for
* k/b.
*/
res = d_splice_alias(inode, dentry);
if (!IS_ERR(fid)) {
if (!res)
v9fs_fid_add(dentry, fid);
else if (!IS_ERR(res))
v9fs_fid_add(res, fid);
else
p9_client_clunk(fid);
}
return res;
}
static int
v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
struct file *file, unsigned flags, umode_t mode)
{
int err;
u32 perm;
struct v9fs_inode *v9inode;
struct v9fs_session_info *v9ses;
struct p9_fid *fid, *inode_fid;
struct dentry *res = NULL;
if (d_in_lookup(dentry)) {
res = v9fs_vfs_lookup(dir, dentry, 0);
if (IS_ERR(res))
return PTR_ERR(res);
if (res)
dentry = res;
}
/* Only creates */
if (!(flags & O_CREAT) || d_really_is_positive(dentry))
return finish_no_open(file, res);
err = 0;
v9ses = v9fs_inode2v9ses(dir);
perm = unixmode2p9mode(v9ses, mode);
fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
v9fs_uflags2omode(flags,
v9fs_proto_dotu(v9ses)));
if (IS_ERR(fid)) {
err = PTR_ERR(fid);
fid = NULL;
goto error;
}
v9fs_invalidate_inode_attr(dir);
v9inode = V9FS_I(d_inode(dentry));
mutex_lock(&v9inode->v_mutex);
if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
!v9inode->writeback_fid &&
((flags & O_ACCMODE) != O_RDONLY)) {
/*
* clone a fid and add it to writeback_fid
* we do it during open time instead of
* page dirty time via write_begin/page_mkwrite
* because we want write after unlink usecase
* to work.
*/
inode_fid = v9fs_writeback_fid(dentry);
if (IS_ERR(inode_fid)) {
err = PTR_ERR(inode_fid);
mutex_unlock(&v9inode->v_mutex);
goto error;
}
v9inode->writeback_fid = (void *) inode_fid;
}
mutex_unlock(&v9inode->v_mutex);
err = finish_open(file, dentry, generic_file_open);
if (err)
goto error;
file->private_data = fid;
if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
v9fs_cache_inode_set_cookie(d_inode(dentry), file);
file->f_mode |= FMODE_CREATED;
out:
dput(res);
return err;
error:
if (fid)
p9_client_clunk(fid);
goto out;
}
/**
* v9fs_vfs_unlink - VFS unlink hook to delete an inode
* @i: inode that is being unlinked
* @d: dentry that is being unlinked
*
*/
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
*
*/
int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
{
return v9fs_remove(i, d, AT_REMOVEDIR);
}
/**
* 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
*
*/
int
v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
unsigned int flags)
{
int retval;
struct inode *old_inode;
struct inode *new_inode;
struct v9fs_session_info *v9ses;
struct p9_fid *oldfid;
struct p9_fid *olddirfid;
struct p9_fid *newdirfid;
struct p9_wstat wstat;
if (flags)
return -EINVAL;
p9_debug(P9_DEBUG_VFS, "\n");
retval = 0;
old_inode = d_inode(old_dentry);
new_inode = d_inode(new_dentry);
v9ses = v9fs_inode2v9ses(old_inode);
oldfid = v9fs_fid_lookup(old_dentry);
if (IS_ERR(oldfid))
return PTR_ERR(oldfid);
olddirfid = clone_fid(v9fs_parent_fid(old_dentry));
if (IS_ERR(olddirfid)) {
retval = PTR_ERR(olddirfid);
goto done;
}
newdirfid = clone_fid(v9fs_parent_fid(new_dentry));
if (IS_ERR(newdirfid)) {
retval = PTR_ERR(newdirfid);
goto clunk_olddir;
}
down_write(&v9ses->rename_sem);
if (v9fs_proto_dotl(v9ses)) {
retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
newdirfid, new_dentry->d_name.name);
if (retval == -EOPNOTSUPP)
retval = p9_client_rename(oldfid, newdirfid,
new_dentry->d_name.name);
if (retval != -EOPNOTSUPP)
goto clunk_newdir;
}
if (old_dentry->d_parent != new_dentry->d_parent) {
/*
* 9P .u can only handle file rename in the same directory
*/
p9_debug(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 = new_dentry->d_name.name;
retval = p9_client_wstat(oldfid, &wstat);
clunk_newdir:
if (!retval) {
if (new_inode) {
if (S_ISDIR(new_inode->i_mode))
clear_nlink(new_inode);
else
v9fs_dec_count(new_inode);
}
if (S_ISDIR(old_inode->i_mode)) {
if (!new_inode)
inc_nlink(new_dir);
v9fs_dec_count(old_dir);
}
v9fs_invalidate_inode_attr(old_inode);
v9fs_invalidate_inode_attr(old_dir);
v9fs_invalidate_inode_attr(new_dir);
/* successful rename */
d_move(old_dentry, new_dentry);
}
up_write(&v9ses->rename_sem);
p9_client_clunk(newdirfid);
clunk_olddir:
p9_client_clunk(olddirfid);
done:
return retval;
}
/**
* v9fs_vfs_getattr - retrieve file metadata
* @path: Object to query
* @stat: metadata structure to populate
* @request_mask: Mask of STATX_xxx flags indicating the caller's interests
* @flags: AT_STATX_xxx setting
*
*/
static int
v9fs_vfs_getattr(const struct path *path, struct kstat *stat,
u32 request_mask, unsigned int flags)
{
struct dentry *dentry = path->dentry;
struct v9fs_session_info *v9ses;
struct p9_fid *fid;
struct p9_wstat *st;
p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
v9ses = v9fs_dentry2v9ses(dentry);
if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
generic_fillattr(d_inode(dentry), stat);
return 0;
}
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, d_inode(dentry), dentry->d_sb);
generic_fillattr(d_inode(dentry), stat);
p9stat_free(st);
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_debug(P9_DEBUG_VFS, "\n");
retval = setattr_prepare(dentry, iattr);
if (retval)
return retval;
retval = -EPERM;
v9ses = v9fs_dentry2v9ses(dentry);
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_proto_dotu(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;
}
/* Write all dirty data */
if (d_is_reg(dentry))
filemap_write_and_wait(d_inode(dentry)->i_mapping);
retval = p9_client_wstat(fid, &wstat);
if (retval < 0)
return retval;
if ((iattr->ia_valid & ATTR_SIZE) &&
iattr->ia_size != i_size_read(d_inode(dentry)))
truncate_setsize(d_inode(dentry), iattr->ia_size);
v9fs_invalidate_inode_attr(d_inode(dentry));
setattr_copy(d_inode(dentry), iattr);
mark_inode_dirty(d_inode(dentry));
return 0;
}
/**
* 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)
{
umode_t mode;
char ext[32];
char tag_name[14];
unsigned int i_nlink;
struct v9fs_session_info *v9ses = sb->s_fs_info;
struct v9fs_inode *v9inode = V9FS_I(inode);
set_nlink(inode, 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_proto_dotu(v9ses)) {
inode->i_uid = stat->n_uid;
inode->i_gid = stat->n_gid;
}
if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
/*
* Hadlink support got added later to
* to the .u extension. So there can be
* server out there that doesn't support
* this even with .u extension. So check
* for non NULL stat->extension
*/
strlcpy(ext, stat->extension, sizeof(ext));
/* HARDLINKCOUNT %u */
sscanf(ext, "%13s %u", tag_name, &i_nlink);
if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
set_nlink(inode, i_nlink);
}
}
mode = p9mode2perm(v9ses, stat);
mode |= inode->i_mode & ~S_IALLUGO;
inode->i_mode = mode;
i_size_write(inode, stat->length);
/* not real number of blocks, but 512 byte ones ... */
inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
}
/**
* 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_vfs_get_link - follow a symlink path
* @dentry: dentry for symlink
* @inode: inode for symlink
* @done: delayed call for when we are done with the return value
*/
static const char *v9fs_vfs_get_link(struct dentry *dentry,
struct inode *inode,
struct delayed_call *done)
{
struct v9fs_session_info *v9ses;
struct p9_fid *fid;
struct p9_wstat *st;
char *res;
if (!dentry)
return ERR_PTR(-ECHILD);
v9ses = v9fs_dentry2v9ses(dentry);
fid = v9fs_fid_lookup(dentry);
p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
if (IS_ERR(fid))
return ERR_CAST(fid);
if (!v9fs_proto_dotu(v9ses))
return ERR_PTR(-EBADF);
st = p9_client_stat(fid);
if (IS_ERR(st))
return ERR_CAST(st);
if (!(st->mode & P9_DMSYMLINK)) {
p9stat_free(st);
kfree(st);
return ERR_PTR(-EINVAL);
}
res = st->extension;
st->extension = NULL;
if (strlen(res) >= PATH_MAX)
res[PATH_MAX - 1] = '\0';
p9stat_free(st);
kfree(st);
set_delayed_call(done, kfree_link, res);
return res;
}
/**
* v9fs_vfs_mkspecial - create a special file
* @dir: inode to create special file in
* @dentry: dentry to create
* @perm: 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,
u32 perm, const char *extension)
{
struct p9_fid *fid;
struct v9fs_session_info *v9ses;
v9ses = v9fs_inode2v9ses(dir);
if (!v9fs_proto_dotu(v9ses)) {
p9_debug(P9_DEBUG_ERROR, "not extended\n");
return -EPERM;
}
fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
P9_OREAD);
if (IS_ERR(fid))
return PTR_ERR(fid);
v9fs_invalidate_inode_attr(dir);
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_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n",
dir->i_ino, dentry, symname);
return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
}
#define U32_MAX_DIGITS 10
/**
* 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;
char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */
struct p9_fid *oldfid;
p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n",
dir->i_ino, dentry, old_dentry);
oldfid = v9fs_fid_clone(old_dentry);
if (IS_ERR(oldfid))
return PTR_ERR(oldfid);
sprintf(name, "%d\n", oldfid->fid);
retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
if (!retval) {
v9fs_refresh_inode(oldfid, d_inode(old_dentry));
v9fs_invalidate_inode_attr(dir);
}
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, umode_t mode, dev_t rdev)
{
struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
int retval;
char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1];
u32 perm;
p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %hx MAJOR: %u MINOR: %u\n",
dir->i_ino, dentry, mode,
MAJOR(rdev), MINOR(rdev));
/* 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
*name = 0;
perm = unixmode2p9mode(v9ses, mode);
retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
return retval;
}
int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
{
int umode;
dev_t rdev;
loff_t i_size;
struct p9_wstat *st;
struct v9fs_session_info *v9ses;
v9ses = v9fs_inode2v9ses(inode);
st = p9_client_stat(fid);
if (IS_ERR(st))
return PTR_ERR(st);
/*
* Don't update inode if the file type is different
*/
umode = p9mode2unixmode(v9ses, st, &rdev);
if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
goto out;
spin_lock(&inode->i_lock);
/*
* We don't want to refresh inode->i_size,
* because we may have cached data
*/
i_size = inode->i_size;
v9fs_stat2inode(st, inode, inode->i_sb);
if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
inode->i_size = i_size;
spin_unlock(&inode->i_lock);
out:
p9stat_free(st);
kfree(st);
return 0;
}
static const struct inode_operations v9fs_dir_inode_operations_dotu = {
.create = v9fs_vfs_create,
.lookup = v9fs_vfs_lookup,
.atomic_open = v9fs_vfs_atomic_open,
.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,
.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,
.atomic_open = v9fs_vfs_atomic_open,
.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 = {
.get_link = v9fs_vfs_get_link,
.getattr = v9fs_vfs_getattr,
.setattr = v9fs_vfs_setattr,
};
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