Commit e5e5558e authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Linus Torvalds
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[PATCH] FUSE - read-only operations



This patch adds the read-only filesystem operations of FUSE.

This contains the following files:

 o dir.c
    - directory, symlink and file-inode operations

The following operations are added:

 o lookup
 o getattr
 o readlink
 o follow_link
 o directory open
 o readdir
 o directory release
 o permission
 o dentry revalidate
 o statfs
Signed-off-by: default avatarMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 334f485d
......@@ -4,4 +4,4 @@
obj-$(CONFIG_FUSE_FS) += fuse.o
fuse-objs := dev.o inode.o
fuse-objs := dev.o dir.o inode.o
......@@ -691,6 +691,13 @@ static struct fuse_req *request_find(struct fuse_conn *fc, u64 unique)
return NULL;
}
/* fget() needs to be done in this context */
static void process_getdir(struct fuse_req *req)
{
struct fuse_getdir_out_i *arg = req->out.args[0].value;
arg->file = fget(arg->fd);
}
static int copy_out_args(struct fuse_copy_state *cs, struct fuse_out *out,
unsigned nbytes)
{
......@@ -770,6 +777,8 @@ static ssize_t fuse_dev_writev(struct file *file, const struct iovec *iov,
if (!err) {
if (req->interrupted)
err = -ENOENT;
else if (req->in.h.opcode == FUSE_GETDIR && !oh.error)
process_getdir(req);
} else if (!req->interrupted)
req->out.h.error = -EIO;
request_end(fc, req);
......
/*
FUSE: Filesystem in Userspace
Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>
This program can be distributed under the terms of the GNU GPL.
See the file COPYING.
*/
#include "fuse_i.h"
#include <linux/pagemap.h>
#include <linux/file.h>
#include <linux/gfp.h>
#include <linux/sched.h>
#include <linux/namei.h>
static inline unsigned long time_to_jiffies(unsigned long sec,
unsigned long nsec)
{
struct timespec ts = {sec, nsec};
return jiffies + timespec_to_jiffies(&ts);
}
static void fuse_lookup_init(struct fuse_req *req, struct inode *dir,
struct dentry *entry,
struct fuse_entry_out *outarg)
{
req->in.h.opcode = FUSE_LOOKUP;
req->in.h.nodeid = get_node_id(dir);
req->inode = dir;
req->in.numargs = 1;
req->in.args[0].size = entry->d_name.len + 1;
req->in.args[0].value = entry->d_name.name;
req->out.numargs = 1;
req->out.args[0].size = sizeof(struct fuse_entry_out);
req->out.args[0].value = outarg;
}
static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd)
{
if (!entry->d_inode || is_bad_inode(entry->d_inode))
return 0;
else if (time_after(jiffies, entry->d_time)) {
int err;
int version;
struct fuse_entry_out outarg;
struct inode *inode = entry->d_inode;
struct fuse_inode *fi = get_fuse_inode(inode);
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_req *req = fuse_get_request_nonint(fc);
if (!req)
return 0;
fuse_lookup_init(req, entry->d_parent->d_inode, entry, &outarg);
request_send_nonint(fc, req);
version = req->out.h.unique;
err = req->out.h.error;
fuse_put_request(fc, req);
if (err || outarg.nodeid != get_node_id(inode) ||
(outarg.attr.mode ^ inode->i_mode) & S_IFMT)
return 0;
fuse_change_attributes(inode, &outarg.attr);
inode->i_version = version;
entry->d_time = time_to_jiffies(outarg.entry_valid,
outarg.entry_valid_nsec);
fi->i_time = time_to_jiffies(outarg.attr_valid,
outarg.attr_valid_nsec);
}
return 1;
}
static struct dentry_operations fuse_dentry_operations = {
.d_revalidate = fuse_dentry_revalidate,
};
static int fuse_lookup_iget(struct inode *dir, struct dentry *entry,
struct inode **inodep)
{
int err;
int version;
struct fuse_entry_out outarg;
struct inode *inode = NULL;
struct fuse_conn *fc = get_fuse_conn(dir);
struct fuse_req *req;
if (entry->d_name.len > FUSE_NAME_MAX)
return -ENAMETOOLONG;
req = fuse_get_request(fc);
if (!req)
return -ERESTARTNOINTR;
fuse_lookup_init(req, dir, entry, &outarg);
request_send(fc, req);
version = req->out.h.unique;
err = req->out.h.error;
if (!err) {
inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
&outarg.attr, version);
if (!inode) {
fuse_send_forget(fc, req, outarg.nodeid, version);
return -ENOMEM;
}
}
fuse_put_request(fc, req);
if (err && err != -ENOENT)
return err;
if (inode) {
struct fuse_inode *fi = get_fuse_inode(inode);
entry->d_time = time_to_jiffies(outarg.entry_valid,
outarg.entry_valid_nsec);
fi->i_time = time_to_jiffies(outarg.attr_valid,
outarg.attr_valid_nsec);
}
entry->d_op = &fuse_dentry_operations;
*inodep = inode;
return 0;
}
int fuse_do_getattr(struct inode *inode)
{
int err;
struct fuse_attr_out arg;
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_req *req = fuse_get_request(fc);
if (!req)
return -ERESTARTNOINTR;
req->in.h.opcode = FUSE_GETATTR;
req->in.h.nodeid = get_node_id(inode);
req->inode = inode;
req->out.numargs = 1;
req->out.args[0].size = sizeof(arg);
req->out.args[0].value = &arg;
request_send(fc, req);
err = req->out.h.error;
fuse_put_request(fc, req);
if (!err) {
if ((inode->i_mode ^ arg.attr.mode) & S_IFMT) {
make_bad_inode(inode);
err = -EIO;
} else {
struct fuse_inode *fi = get_fuse_inode(inode);
fuse_change_attributes(inode, &arg.attr);
fi->i_time = time_to_jiffies(arg.attr_valid,
arg.attr_valid_nsec);
}
}
return err;
}
static int fuse_revalidate(struct dentry *entry)
{
struct inode *inode = entry->d_inode;
struct fuse_inode *fi = get_fuse_inode(inode);
struct fuse_conn *fc = get_fuse_conn(inode);
if (get_node_id(inode) == FUSE_ROOT_ID) {
if (current->fsuid != fc->user_id)
return -EACCES;
} else if (time_before_eq(jiffies, fi->i_time))
return 0;
return fuse_do_getattr(inode);
}
static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd)
{
struct fuse_conn *fc = get_fuse_conn(inode);
if (current->fsuid != fc->user_id)
return -EACCES;
else {
int mode = inode->i_mode;
if ((mask & MAY_WRITE) && IS_RDONLY(inode) &&
(S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
return -EROFS;
if ((mask & MAY_EXEC) && !S_ISDIR(mode) && !(mode & S_IXUGO))
return -EACCES;
return 0;
}
}
static int parse_dirfile(char *buf, size_t nbytes, struct file *file,
void *dstbuf, filldir_t filldir)
{
while (nbytes >= FUSE_NAME_OFFSET) {
struct fuse_dirent *dirent = (struct fuse_dirent *) buf;
size_t reclen = FUSE_DIRENT_SIZE(dirent);
int over;
if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
return -EIO;
if (reclen > nbytes)
break;
over = filldir(dstbuf, dirent->name, dirent->namelen,
file->f_pos, dirent->ino, dirent->type);
if (over)
break;
buf += reclen;
nbytes -= reclen;
file->f_pos = dirent->off;
}
return 0;
}
static int fuse_checkdir(struct file *cfile, struct file *file)
{
struct inode *inode;
if (!cfile)
return -EIO;
inode = cfile->f_dentry->d_inode;
if (!S_ISREG(inode->i_mode)) {
fput(cfile);
return -EIO;
}
file->private_data = cfile;
return 0;
}
static int fuse_getdir(struct file *file)
{
struct inode *inode = file->f_dentry->d_inode;
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_req *req = fuse_get_request(fc);
struct fuse_getdir_out_i outarg;
int err;
if (!req)
return -ERESTARTNOINTR;
req->in.h.opcode = FUSE_GETDIR;
req->in.h.nodeid = get_node_id(inode);
req->inode = inode;
req->out.numargs = 1;
req->out.args[0].size = sizeof(struct fuse_getdir_out);
req->out.args[0].value = &outarg;
request_send(fc, req);
err = req->out.h.error;
fuse_put_request(fc, req);
if (!err)
err = fuse_checkdir(outarg.file, file);
return err;
}
static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
{
struct file *cfile = file->private_data;
char *buf;
int ret;
if (!cfile) {
ret = fuse_getdir(file);
if (ret)
return ret;
cfile = file->private_data;
}
buf = (char *) __get_free_page(GFP_KERNEL);
if (!buf)
return -ENOMEM;
ret = kernel_read(cfile, file->f_pos, buf, PAGE_SIZE);
if (ret > 0)
ret = parse_dirfile(buf, ret, file, dstbuf, filldir);
free_page((unsigned long) buf);
return ret;
}
static char *read_link(struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_req *req = fuse_get_request(fc);
char *link;
if (!req)
return ERR_PTR(-ERESTARTNOINTR);
link = (char *) __get_free_page(GFP_KERNEL);
if (!link) {
link = ERR_PTR(-ENOMEM);
goto out;
}
req->in.h.opcode = FUSE_READLINK;
req->in.h.nodeid = get_node_id(inode);
req->inode = inode;
req->out.argvar = 1;
req->out.numargs = 1;
req->out.args[0].size = PAGE_SIZE - 1;
req->out.args[0].value = link;
request_send(fc, req);
if (req->out.h.error) {
free_page((unsigned long) link);
link = ERR_PTR(req->out.h.error);
} else
link[req->out.args[0].size] = '\0';
out:
fuse_put_request(fc, req);
return link;
}
static void free_link(char *link)
{
if (!IS_ERR(link))
free_page((unsigned long) link);
}
static void *fuse_follow_link(struct dentry *dentry, struct nameidata *nd)
{
nd_set_link(nd, read_link(dentry));
return NULL;
}
static void fuse_put_link(struct dentry *dentry, struct nameidata *nd, void *c)
{
free_link(nd_get_link(nd));
}
static int fuse_dir_open(struct inode *inode, struct file *file)
{
file->private_data = NULL;
return 0;
}
static int fuse_dir_release(struct inode *inode, struct file *file)
{
struct file *cfile = file->private_data;
if (cfile)
fput(cfile);
return 0;
}
static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry,
struct kstat *stat)
{
struct inode *inode = entry->d_inode;
int err = fuse_revalidate(entry);
if (!err)
generic_fillattr(inode, stat);
return err;
}
static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
struct nameidata *nd)
{
struct inode *inode;
int err = fuse_lookup_iget(dir, entry, &inode);
if (err)
return ERR_PTR(err);
if (inode && S_ISDIR(inode->i_mode)) {
/* Don't allow creating an alias to a directory */
struct dentry *alias = d_find_alias(inode);
if (alias && !(alias->d_flags & DCACHE_DISCONNECTED)) {
dput(alias);
iput(inode);
return ERR_PTR(-EIO);
}
}
return d_splice_alias(inode, entry);
}
static struct inode_operations fuse_dir_inode_operations = {
.lookup = fuse_lookup,
.permission = fuse_permission,
.getattr = fuse_getattr,
};
static struct file_operations fuse_dir_operations = {
.read = generic_read_dir,
.readdir = fuse_readdir,
.open = fuse_dir_open,
.release = fuse_dir_release,
};
static struct inode_operations fuse_common_inode_operations = {
.permission = fuse_permission,
.getattr = fuse_getattr,
};
static struct inode_operations fuse_symlink_inode_operations = {
.follow_link = fuse_follow_link,
.put_link = fuse_put_link,
.readlink = generic_readlink,
.getattr = fuse_getattr,
};
void fuse_init_common(struct inode *inode)
{
inode->i_op = &fuse_common_inode_operations;
}
void fuse_init_dir(struct inode *inode)
{
inode->i_op = &fuse_dir_inode_operations;
inode->i_fop = &fuse_dir_operations;
}
void fuse_init_symlink(struct inode *inode)
{
inode->i_op = &fuse_symlink_inode_operations;
}
......@@ -30,6 +30,9 @@ struct fuse_inode {
* and kernel */
u64 nodeid;
/** The request used for sending the FORGET message */
struct fuse_req *forget_req;
/** Time in jiffies until the file attributes are valid */
unsigned long i_time;
};
......@@ -129,6 +132,7 @@ struct fuse_req {
/** Data for asynchronous requests */
union {
struct fuse_forget_in forget_in;
struct fuse_init_in_out init_in_out;
} misc;
......@@ -197,6 +201,11 @@ struct fuse_conn {
struct backing_dev_info bdi;
};
struct fuse_getdir_out_i {
int fd;
void *file; /* Used by kernel only */
};
static inline struct fuse_conn **get_fuse_conn_super_p(struct super_block *sb)
{
return (struct fuse_conn **) &sb->s_fs_info;
......@@ -239,6 +248,38 @@ extern struct file_operations fuse_dev_operations;
*/
extern spinlock_t fuse_lock;
/**
* Get a filled in inode
*/
struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
int generation, struct fuse_attr *attr, int version);
/**
* Send FORGET command
*/
void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
unsigned long nodeid, int version);
/**
* Initialise inode operations on regular files and special files
*/
void fuse_init_common(struct inode *inode);
/**
* Initialise inode and file operations on a directory
*/
void fuse_init_dir(struct inode *inode);
/**
* Initialise inode operations on a symlink
*/
void fuse_init_symlink(struct inode *inode);
/**
* Change attributes of an inode
*/
void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr);
/**
* Check if the connection can be released, and if yes, then free the
* connection structure
......@@ -306,6 +347,16 @@ void request_send_noreply(struct fuse_conn *fc, struct fuse_req *req);
*/
void request_send_background(struct fuse_conn *fc, struct fuse_req *req);
/**
* Get the attributes of a file
*/
int fuse_do_getattr(struct inode *inode);
/**
* Invalidate inode attributes
*/
void fuse_invalidate_attr(struct inode *inode);
/**
* Send the INIT message
*/
......
......@@ -51,12 +51,20 @@ static struct inode *fuse_alloc_inode(struct super_block *sb)
fi = get_fuse_inode(inode);
fi->i_time = jiffies - 1;
fi->nodeid = 0;
fi->forget_req = fuse_request_alloc();
if (!fi->forget_req) {
kmem_cache_free(fuse_inode_cachep, inode);
return NULL;
}
return inode;
}
static void fuse_destroy_inode(struct inode *inode)
{
struct fuse_inode *fi = get_fuse_inode(inode);
if (fi->forget_req)
fuse_request_free(fi->forget_req);
kmem_cache_free(fuse_inode_cachep, inode);
}
......@@ -65,8 +73,27 @@ static void fuse_read_inode(struct inode *inode)
/* No op */
}
void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
unsigned long nodeid, int version)
{
struct fuse_forget_in *inarg = &req->misc.forget_in;
inarg->version = version;
req->in.h.opcode = FUSE_FORGET;
req->in.h.nodeid = nodeid;
req->in.numargs = 1;
req->in.args[0].size = sizeof(struct fuse_forget_in);
req->in.args[0].value = inarg;
request_send_noreply(fc, req);
}
static void fuse_clear_inode(struct inode *inode)
{
struct fuse_conn *fc = get_fuse_conn(inode);
if (fc) {
struct fuse_inode *fi = get_fuse_inode(inode);
fuse_send_forget(fc, fi->forget_req, fi->nodeid, inode->i_version);
fi->forget_req = NULL;
}
}
void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr)
......@@ -94,6 +121,22 @@ static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
{
inode->i_mode = attr->mode & S_IFMT;
i_size_write(inode, attr->size);
if (S_ISREG(inode->i_mode)) {
fuse_init_common(inode);
} else if (S_ISDIR(inode->i_mode))
fuse_init_dir(inode);
else if (S_ISLNK(inode->i_mode))
fuse_init_symlink(inode);
else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
fuse_init_common(inode);
init_special_inode(inode, inode->i_mode,
new_decode_dev(attr->rdev));
} else {
/* Don't let user create weird files */
inode->i_mode = S_IFREG;
fuse_init_common(inode);
}
}
static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
......@@ -158,6 +201,43 @@ static void fuse_put_super(struct super_block *sb)
spin_unlock(&fuse_lock);
}
static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
{
stbuf->f_type = FUSE_SUPER_MAGIC;
stbuf->f_bsize = attr->bsize;
stbuf->f_blocks = attr->blocks;
stbuf->f_bfree = attr->bfree;
stbuf->f_bavail = attr->bavail;
stbuf->f_files = attr->files;
stbuf->f_ffree = attr->ffree;
stbuf->f_namelen = attr->namelen;
/* fsid is left zero */
}
static int fuse_statfs(struct super_block *sb, struct kstatfs *buf)
{
struct fuse_conn *fc = get_fuse_conn_super(sb);
struct fuse_req *req;
struct fuse_statfs_out outarg;
int err;
req = fuse_get_request(fc);
if (!req)
return -ERESTARTSYS;
req->in.numargs = 0;
req->in.h.opcode = FUSE_STATFS;
req->out.numargs = 1;