linux/fs/coda/inode.c
Aleksa Sarai 66e5cfee62 coda: use param->file for FSCONFIG_SET_FD
While the old code did support FSCONFIG_SET_FD, there's no need to
re-get the file the fs_context infrastructure already grabbed for us.

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Link: https://lore.kernel.org/r/20240731-fsconfig-fsparam_fd-fixes-v2-2-e7c472224417@cyphar.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-19 13:45:03 +02:00

403 lines
8.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Super block/filesystem wide operations
*
* Copyright (C) 1996 Peter J. Braam <braam@maths.ox.ac.uk> and
* Michael Callahan <callahan@maths.ox.ac.uk>
*
* Rewritten for Linux 2.1. Peter Braam <braam@cs.cmu.edu>
* Copyright (C) Carnegie Mellon University
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/stat.h>
#include <linux/errno.h>
#include <linux/unistd.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/file.h>
#include <linux/vfs.h>
#include <linux/slab.h>
#include <linux/pid_namespace.h>
#include <linux/uaccess.h>
#include <linux/fs.h>
#include <linux/fs_context.h>
#include <linux/fs_parser.h>
#include <linux/vmalloc.h>
#include <linux/coda.h>
#include "coda_psdev.h"
#include "coda_linux.h"
#include "coda_cache.h"
#include "coda_int.h"
/* VFS super_block ops */
static void coda_evict_inode(struct inode *);
static void coda_put_super(struct super_block *);
static int coda_statfs(struct dentry *dentry, struct kstatfs *buf);
static struct kmem_cache * coda_inode_cachep;
static struct inode *coda_alloc_inode(struct super_block *sb)
{
struct coda_inode_info *ei;
ei = alloc_inode_sb(sb, coda_inode_cachep, GFP_KERNEL);
if (!ei)
return NULL;
memset(&ei->c_fid, 0, sizeof(struct CodaFid));
ei->c_flags = 0;
ei->c_uid = GLOBAL_ROOT_UID;
ei->c_cached_perm = 0;
spin_lock_init(&ei->c_lock);
return &ei->vfs_inode;
}
static void coda_free_inode(struct inode *inode)
{
kmem_cache_free(coda_inode_cachep, ITOC(inode));
}
static void init_once(void *foo)
{
struct coda_inode_info *ei = (struct coda_inode_info *) foo;
inode_init_once(&ei->vfs_inode);
}
int __init coda_init_inodecache(void)
{
coda_inode_cachep = kmem_cache_create("coda_inode_cache",
sizeof(struct coda_inode_info), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT,
init_once);
if (coda_inode_cachep == NULL)
return -ENOMEM;
return 0;
}
void coda_destroy_inodecache(void)
{
/*
* Make sure all delayed rcu free inodes are flushed before we
* destroy cache.
*/
rcu_barrier();
kmem_cache_destroy(coda_inode_cachep);
}
static int coda_reconfigure(struct fs_context *fc)
{
sync_filesystem(fc->root->d_sb);
fc->sb_flags |= SB_NOATIME;
return 0;
}
/* exported operations */
static const struct super_operations coda_super_operations =
{
.alloc_inode = coda_alloc_inode,
.free_inode = coda_free_inode,
.evict_inode = coda_evict_inode,
.put_super = coda_put_super,
.statfs = coda_statfs,
};
struct coda_fs_context {
int idx;
};
enum {
Opt_fd,
};
static const struct fs_parameter_spec coda_param_specs[] = {
fsparam_fd ("fd", Opt_fd),
{}
};
static int coda_set_idx(struct fs_context *fc, struct file *file)
{
struct coda_fs_context *ctx = fc->fs_private;
struct inode *inode;
int idx;
inode = file_inode(file);
if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {
return invalf(fc, "coda: Not coda psdev");
}
idx = iminor(inode);
if (idx < 0 || idx >= MAX_CODADEVS)
return invalf(fc, "coda: Bad minor number");
ctx->idx = idx;
return 0;
}
static int coda_parse_fd(struct fs_context *fc, struct fs_parameter *param,
struct fs_parse_result *result)
{
struct file *file;
int err;
if (param->type == fs_value_is_file) {
file = param->file;
param->file = NULL;
} else {
file = fget(result->uint_32);
}
if (!file)
return -EBADF;
err = coda_set_idx(fc, file);
fput(file);
return err;
}
static int coda_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
struct fs_parse_result result;
int opt;
opt = fs_parse(fc, coda_param_specs, param, &result);
if (opt < 0)
return opt;
switch (opt) {
case Opt_fd:
return coda_parse_fd(fc, param, &result);
}
return 0;
}
/*
* Parse coda's binary mount data form. We ignore any errors and go with index
* 0 if we get one for backward compatibility.
*/
static int coda_parse_monolithic(struct fs_context *fc, void *_data)
{
struct file *file;
struct coda_mount_data *data = _data;
if (!data)
return invalf(fc, "coda: Bad mount data");
if (data->version != CODA_MOUNT_VERSION)
return invalf(fc, "coda: Bad mount version");
file = fget(data->fd);
if (file) {
coda_set_idx(fc, file);
fput(file);
}
return 0;
}
static int coda_fill_super(struct super_block *sb, struct fs_context *fc)
{
struct coda_fs_context *ctx = fc->fs_private;
struct inode *root = NULL;
struct venus_comm *vc;
struct CodaFid fid;
int error;
infof(fc, "coda: device index: %i\n", ctx->idx);
vc = &coda_comms[ctx->idx];
mutex_lock(&vc->vc_mutex);
if (!vc->vc_inuse) {
errorf(fc, "coda: No pseudo device");
error = -EINVAL;
goto unlock_out;
}
if (vc->vc_sb) {
errorf(fc, "coda: Device already mounted");
error = -EBUSY;
goto unlock_out;
}
vc->vc_sb = sb;
mutex_unlock(&vc->vc_mutex);
sb->s_fs_info = vc;
sb->s_flags |= SB_NOATIME;
sb->s_blocksize = 4096; /* XXXXX what do we put here?? */
sb->s_blocksize_bits = 12;
sb->s_magic = CODA_SUPER_MAGIC;
sb->s_op = &coda_super_operations;
sb->s_d_op = &coda_dentry_operations;
sb->s_time_gran = 1;
sb->s_time_min = S64_MIN;
sb->s_time_max = S64_MAX;
error = super_setup_bdi(sb);
if (error)
goto error;
/* get root fid from Venus: this needs the root inode */
error = venus_rootfid(sb, &fid);
if ( error ) {
pr_warn("%s: coda_get_rootfid failed with %d\n",
__func__, error);
goto error;
}
pr_info("%s: rootfid is %s\n", __func__, coda_f2s(&fid));
/* make root inode */
root = coda_cnode_make(&fid, sb);
if (IS_ERR(root)) {
error = PTR_ERR(root);
pr_warn("Failure of coda_cnode_make for root: error %d\n",
error);
goto error;
}
pr_info("%s: rootinode is %ld dev %s\n",
__func__, root->i_ino, root->i_sb->s_id);
sb->s_root = d_make_root(root);
if (!sb->s_root) {
error = -EINVAL;
goto error;
}
return 0;
error:
mutex_lock(&vc->vc_mutex);
vc->vc_sb = NULL;
sb->s_fs_info = NULL;
unlock_out:
mutex_unlock(&vc->vc_mutex);
return error;
}
static void coda_put_super(struct super_block *sb)
{
struct venus_comm *vcp = coda_vcp(sb);
mutex_lock(&vcp->vc_mutex);
vcp->vc_sb = NULL;
sb->s_fs_info = NULL;
mutex_unlock(&vcp->vc_mutex);
mutex_destroy(&vcp->vc_mutex);
pr_info("Bye bye.\n");
}
static void coda_evict_inode(struct inode *inode)
{
truncate_inode_pages_final(&inode->i_data);
clear_inode(inode);
coda_cache_clear_inode(inode);
}
int coda_getattr(struct mnt_idmap *idmap, const struct path *path,
struct kstat *stat, u32 request_mask, unsigned int flags)
{
int err = coda_revalidate_inode(d_inode(path->dentry));
if (!err)
generic_fillattr(&nop_mnt_idmap, request_mask,
d_inode(path->dentry), stat);
return err;
}
int coda_setattr(struct mnt_idmap *idmap, struct dentry *de,
struct iattr *iattr)
{
struct inode *inode = d_inode(de);
struct coda_vattr vattr;
int error;
memset(&vattr, 0, sizeof(vattr));
inode_set_ctime_current(inode);
coda_iattr_to_vattr(iattr, &vattr);
vattr.va_type = C_VNON; /* cannot set type */
/* Venus is responsible for truncating the container-file!!! */
error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
if (!error) {
coda_vattr_to_iattr(inode, &vattr);
coda_cache_clear_inode(inode);
}
return error;
}
const struct inode_operations coda_file_inode_operations = {
.permission = coda_permission,
.getattr = coda_getattr,
.setattr = coda_setattr,
};
static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
{
int error;
error = venus_statfs(dentry, buf);
if (error) {
/* fake something like AFS does */
buf->f_blocks = 9000000;
buf->f_bfree = 9000000;
buf->f_bavail = 9000000;
buf->f_files = 9000000;
buf->f_ffree = 9000000;
}
/* and fill in the rest */
buf->f_type = CODA_SUPER_MAGIC;
buf->f_bsize = 4096;
buf->f_namelen = CODA_MAXNAMLEN;
return 0;
}
static int coda_get_tree(struct fs_context *fc)
{
if (task_active_pid_ns(current) != &init_pid_ns)
return -EINVAL;
return get_tree_nodev(fc, coda_fill_super);
}
static void coda_free_fc(struct fs_context *fc)
{
kfree(fc->fs_private);
}
static const struct fs_context_operations coda_context_ops = {
.free = coda_free_fc,
.parse_param = coda_parse_param,
.parse_monolithic = coda_parse_monolithic,
.get_tree = coda_get_tree,
.reconfigure = coda_reconfigure,
};
static int coda_init_fs_context(struct fs_context *fc)
{
struct coda_fs_context *ctx;
ctx = kzalloc(sizeof(struct coda_fs_context), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
fc->fs_private = ctx;
fc->ops = &coda_context_ops;
return 0;
}
struct file_system_type coda_fs_type = {
.owner = THIS_MODULE,
.name = "coda",
.init_fs_context = coda_init_fs_context,
.parameters = coda_param_specs,
.kill_sb = kill_anon_super,
.fs_flags = FS_BINARY_MOUNTDATA,
};
MODULE_ALIAS_FS("coda");