trunk/kernel/dir.c

/*
    FUSE: Filesystem in Userspace
    Copyright (C) 2001-2004  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/slab.h>
#include <linux/file.h>

static struct inode_operations fuse_dir_inode_operations;
static struct inode_operations fuse_file_inode_operations;
static struct inode_operations fuse_symlink_inode_operations;

static struct file_operations fuse_dir_operations;

static struct dentry_operations fuse_dentry_operations;

#ifndef KERNEL_2_6
#define new_decode_dev(x) (x)
#define new_encode_dev(x) (x)
#endif

static void change_attributes(struct inode *inode, struct fuse_attr *attr)
{
        if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size) {
#ifdef KERNEL_2_6
                invalidate_inode_pages(inode->i_mapping);
#else
                invalidate_inode_pages(inode);
#endif
        }

        inode->i_mode    = (inode->i_mode & S_IFMT) + (attr->mode & 07777);
        inode->i_nlink   = attr->nlink;
        inode->i_uid     = attr->uid;
        inode->i_gid     = attr->gid;
        i_size_write(inode, attr->size);
        inode->i_blksize = PAGE_CACHE_SIZE;
        inode->i_blocks  = attr->blocks;
#ifdef KERNEL_2_6
        inode->i_atime.tv_sec   = attr->atime;
        inode->i_atime.tv_nsec  = attr->atimensec;
        inode->i_mtime.tv_sec   = attr->mtime;
        inode->i_mtime.tv_nsec  = attr->mtimensec;
        inode->i_ctime.tv_sec   = attr->ctime;
        inode->i_ctime.tv_nsec  = attr->ctimensec;
#else
        inode->i_atime   = attr->atime;
        inode->i_mtime   = attr->mtime;
        inode->i_ctime   = attr->ctime;
#endif
}

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)) {
                inode->i_op = &fuse_file_inode_operations;
                fuse_init_file_inode(inode);
        }
        else if (S_ISDIR(inode->i_mode)) {
                inode->i_op = &fuse_dir_inode_operations;
                inode->i_fop = &fuse_dir_operations;
        }
        else if (S_ISLNK(inode->i_mode)) {
                inode->i_op = &fuse_symlink_inode_operations;
        }
        else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) || 
                 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)){
                inode->i_op = &fuse_file_inode_operations;
                init_special_inode(inode, inode->i_mode,
                                   new_decode_dev(attr->rdev));
        } else
                printk("fuse_init_inode: bad file type: %o\n", inode->i_mode);
}

struct inode *fuse_iget(struct super_block *sb, ino_t ino, int generation,
                        struct fuse_attr *attr, int version)
{
        struct inode *inode;

        inode = iget(sb, ino);
        if (inode) {
                if (!INO_FI(inode)) {
                        struct fuse_inode *fi = fuse_inode_alloc();
                        if (!fi) {
                                iput(inode);
                                inode = NULL;
                                goto out;
                        }
                        INO_FI(inode) = fi;
                        inode->i_generation = generation;
                        fuse_init_inode(inode, attr);
                } else if (inode->i_generation != generation)
                        printk("fuse_iget: bad generation for ino %lu\n", ino);

                change_attributes(inode, attr);
                inode->i_version = version;
        }
 out:

        return inode;
}

static int fuse_send_lookup(struct fuse_conn *fc, struct fuse_req *req,
                            struct inode *dir, struct dentry *entry, 
                            struct fuse_entry_out *outarg, int *version)
{
        req->in.h.opcode = FUSE_LOOKUP;
        req->in.h.ino = dir->i_ino;
        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;
        request_send(fc, req);
        *version = req->out.h.unique;
        return req->out.h.error;
}

static int fuse_do_lookup(struct inode *dir, struct dentry *entry,
                          struct fuse_entry_out *outarg, int *version)
{
        struct fuse_conn *fc = INO_FC(dir);
        struct fuse_req *req;
        int err;

        if (entry->d_name.len > FUSE_NAME_MAX)
                return -ENAMETOOLONG;
        req = fuse_get_request(fc);
        if (!req)
                return -ERESTARTSYS;
        
        err = fuse_send_lookup(fc, req, dir, entry, outarg, version);
        fuse_put_request(fc, req);
        return err;
}

static inline unsigned long time_to_jiffies(unsigned long sec,
                                            unsigned long nsec)
{
        /* prevent wrapping of jiffies */
        if (sec + 1 >= LONG_MAX / HZ)
                return 0;
        
        return jiffies + sec * HZ + nsec / (1000000000 / HZ);
}

static int fuse_lookup_iget(struct inode *dir, struct dentry *entry,
                            struct inode **inodep)
{
        struct fuse_conn *fc = INO_FC(dir);
        int err;
        struct fuse_entry_out outarg;
        int version;
        struct inode *inode = NULL;
        struct fuse_req *req;

        if (entry->d_name.len > FUSE_NAME_MAX)
                return -ENAMETOOLONG;
        req = fuse_get_request(fc);
        if (!req)
                return -ERESTARTSYS;

        err = fuse_send_lookup(fc, req, dir, entry, &outarg, &version);
        if (!err) {
                inode = fuse_iget(dir->i_sb, outarg.ino, outarg.generation,
                                  &outarg.attr, version);
                if (!inode) {
                        fuse_send_forget(fc, req, outarg.ino, version);
                        return -ENOMEM;
                }
        } 
        fuse_put_request(fc, req);
        if (err && err != -ENOENT)
                return err;

        if (inode) {
                struct fuse_inode *fi = INO_FI(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;
}

static void fuse_invalidate_attr(struct inode *inode)
{
        struct fuse_inode *fi = INO_FI(inode);
        fi->i_time = jiffies - 1;
}

static int lookup_new_entry(struct fuse_conn *fc, struct fuse_req *req,
                            struct inode *dir, struct dentry *entry,
                            struct fuse_entry_out *outarg, int version,
                            int mode)
{
        struct inode *inode;
        struct fuse_inode *fi;
        inode = fuse_iget(dir->i_sb, outarg->ino, outarg->generation, 
                          &outarg->attr, version);
        if (!inode) {
                fuse_send_forget(fc, req, outarg->ino, version);
                return -ENOMEM;
        }
        fuse_put_request(fc, req);

        /* Don't allow userspace to do really stupid things... */
        if ((inode->i_mode ^ mode) & S_IFMT) {
                iput(inode);
                printk("fuse_mknod: inode has wrong type\n");
                return -EINVAL;
        }

        entry->d_time = time_to_jiffies(outarg->entry_valid,
                                        outarg->entry_valid_nsec);

        fi = INO_FI(inode);
        fi->i_time = time_to_jiffies(outarg->attr_valid,
                                     outarg->attr_valid_nsec);

        d_instantiate(entry, inode);
        fuse_invalidate_attr(dir);
        return 0;
}


static int _fuse_mknod(struct inode *dir, struct dentry *entry, int mode,
                      dev_t rdev)
{
        struct fuse_conn *fc = INO_FC(dir);
        struct fuse_req *req = fuse_get_request(fc);
        struct fuse_mknod_in inarg;
        struct fuse_entry_out outarg;
        int err;

        if (!req)
                return -ERESTARTSYS;

        memset(&inarg, 0, sizeof(inarg));
        inarg.mode = mode;
        inarg.rdev = new_encode_dev(rdev);
        req->in.h.opcode = FUSE_MKNOD;
        req->in.h.ino = dir->i_ino;
        req->in.numargs = 2;
        req->in.args[0].size = sizeof(inarg);
        req->in.args[0].value = &inarg;
        req->in.args[1].size = entry->d_name.len + 1;
        req->in.args[1].value = entry->d_name.name;
        req->out.numargs = 1;
        req->out.args[0].size = sizeof(outarg);
        req->out.args[0].value = &outarg;
        request_send(fc, req);
        err = req->out.h.error;
        if (!err)
                err = lookup_new_entry(fc, req, dir, entry, &outarg,
                                       req->out.h.unique, mode);
        else
                fuse_put_request(fc, req);
        return err;
}

static int _fuse_create(struct inode *dir, struct dentry *entry, int mode)
{
        return _fuse_mknod(dir, entry, mode, 0);
}


static int fuse_mkdir(struct inode *dir, struct dentry *entry, int mode)
{
        struct fuse_conn *fc = INO_FC(dir);
        struct fuse_req *req = fuse_get_request(fc);
        struct fuse_mkdir_in inarg;
        struct fuse_entry_out outarg;
        int err;

        if (!req)
                return -ERESTARTSYS;

        memset(&inarg, 0, sizeof(inarg));
        inarg.mode = mode;
        req->in.h.opcode = FUSE_MKDIR;
        req->in.h.ino = dir->i_ino;
        req->in.numargs = 2;
        req->in.args[0].size = sizeof(inarg);
        req->in.args[0].value = &inarg;
        req->in.args[1].size = entry->d_name.len + 1;
        req->in.args[1].value = entry->d_name.name;
        req->out.numargs = 1;
        req->out.args[0].size = sizeof(outarg);
        req->out.args[0].value = &outarg;
        request_send(fc, req);
        err = req->out.h.error;
        if (!err)
                err = lookup_new_entry(fc, req, dir, entry, &outarg,
                                       req->out.h.unique, S_IFDIR);
        else
                fuse_put_request(fc, req);
        return err;
}

static int fuse_symlink(struct inode *dir, struct dentry *entry,
                        const char *link)
{
        struct fuse_conn *fc = INO_FC(dir);
        struct fuse_req *req;
        struct fuse_entry_out outarg;
        unsigned int len = strlen(link) + 1;
        int err;
        
        if (len > FUSE_SYMLINK_MAX)
                return -ENAMETOOLONG;

        req = fuse_get_request(fc);
        if (!req)
                return -ERESTARTSYS;

        req->in.h.opcode = FUSE_SYMLINK;
        req->in.h.ino = dir->i_ino;
        req->in.numargs = 2;
        req->in.args[0].size = entry->d_name.len + 1;
        req->in.args[0].value = entry->d_name.name;
        req->in.args[1].size = len;
        req->in.args[1].value = link;
        req->out.numargs = 1;
        req->out.args[0].size = sizeof(outarg);
        req->out.args[0].value = &outarg;
        request_send(fc, req);
        err = req->out.h.error;
        if (!err)
                err = lookup_new_entry(fc, req, dir, entry, &outarg,
                                       req->out.h.unique, S_IFLNK);
        else
                fuse_put_request(fc, req);
        return err;
}

static int fuse_unlink(struct inode *dir, struct dentry *entry)
{
        struct fuse_conn *fc = INO_FC(dir);
        struct fuse_req *req = fuse_get_request(fc);
        int err;
        
        if (!req)
                return -ERESTARTSYS;

        req->in.h.opcode = FUSE_UNLINK;
        req->in.h.ino = dir->i_ino;
        req->in.numargs = 1;
        req->in.args[0].size = entry->d_name.len + 1;
        req->in.args[0].value = entry->d_name.name;
        request_send(fc, req);
        err = req->out.h.error;
        if (!err) {
                struct inode *inode = entry->d_inode;
                
                /* Set nlink to zero so the inode can be cleared, if
                   the inode does have more links this will be
                   discovered at the next lookup/getattr */
                inode->i_nlink = 0;
                fuse_invalidate_attr(inode);
                fuse_invalidate_attr(dir);
        }
        fuse_put_request(fc, req);
        return err;
}

static int fuse_rmdir(struct inode *dir, struct dentry *entry)
{
        struct fuse_conn *fc = INO_FC(dir);
        struct fuse_req *req = fuse_get_request(fc);
        int err;
        
        if (!req)
                return -ERESTARTSYS;

        req->in.h.opcode = FUSE_RMDIR;
        req->in.h.ino = dir->i_ino;
        req->in.numargs = 1;
        req->in.args[0].size = entry->d_name.len + 1;
        req->in.args[0].value = entry->d_name.name;
        request_send(fc, req);
        err = req->out.h.error;
        if (!err) {
                entry->d_inode->i_nlink = 0;
                fuse_invalidate_attr(dir);
        }
        fuse_put_request(fc, req);
        return err;
}

static int fuse_rename(struct inode *olddir, struct dentry *oldent,
                       struct inode *newdir, struct dentry *newent)
{
        struct fuse_conn *fc = INO_FC(olddir);
        struct fuse_req *req = fuse_get_request(fc);
        struct fuse_rename_in inarg;
        int err;

        if (!req)
                return -ERESTARTSYS;

        memset(&inarg, 0, sizeof(inarg));
        inarg.newdir = newdir->i_ino;
        req->in.h.opcode = FUSE_RENAME;
        req->in.h.ino = olddir->i_ino;
        req->in.numargs = 3;
        req->in.args[0].size = sizeof(inarg);
        req->in.args[0].value = &inarg;
        req->in.args[1].size = oldent->d_name.len + 1;
        req->in.args[1].value = oldent->d_name.name;
        req->in.args[2].size = newent->d_name.len + 1;
        req->in.args[2].value = newent->d_name.name;
        request_send(fc, req);
        err = req->out.h.error;
        fuse_put_request(fc, req);
        if (!err) {
                fuse_invalidate_attr(olddir);
                if (olddir != newdir)
                        fuse_invalidate_attr(newdir);
        }
        return err;
}

static int fuse_link(struct dentry *entry, struct inode *newdir,
                     struct dentry *newent)
{
        struct inode *inode = entry->d_inode;
        struct fuse_conn *fc = INO_FC(inode);
        struct fuse_req *req = fuse_get_request(fc);
        struct fuse_link_in inarg;
        struct fuse_entry_out outarg;
        int err;

        if (!req)
                return -ERESTARTSYS;

        memset(&inarg, 0, sizeof(inarg));
        inarg.newdir = newdir->i_ino;
        req->in.h.opcode = FUSE_LINK;
        req->in.h.ino = inode->i_ino;
        req->in.numargs = 2;
        req->in.args[0].size = sizeof(inarg);
        req->in.args[0].value = &inarg;
        req->in.args[1].size = newent->d_name.len + 1;
        req->in.args[1].value = newent->d_name.name;
        req->out.numargs = 1;
        req->out.args[0].size = sizeof(outarg);
        req->out.args[0].value = &outarg;
        request_send(fc, req);
        err = req->out.h.error;
        if (!err) {
                /* Invalidate old entry, so attributes are refreshed */
                d_invalidate(entry);
                err = lookup_new_entry(fc, req, newdir, newent, &outarg,
                                       req->out.h.unique, inode->i_mode);
        } else
                fuse_put_request(fc, req);
        return err;
}

int fuse_do_getattr(struct inode *inode)
{
        struct fuse_inode *fi = INO_FI(inode);
        struct fuse_conn *fc = INO_FC(inode);
        struct fuse_req *req = fuse_get_request(fc);
        struct fuse_attr_out arg;
        int err;

        if (!req)
                return -ERESTARTSYS;

        req->in.h.opcode = FUSE_GETATTR;
        req->in.h.ino = inode->i_ino;
        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; 
        if (!err) {
                change_attributes(inode, &arg.attr);
                fi->i_time = time_to_jiffies(arg.attr_valid,
                                             arg.attr_valid_nsec);
        }
        fuse_put_request(fc, req);
        return err;
}

static int fuse_revalidate(struct dentry *entry)
{
        struct inode *inode = entry->d_inode;
        struct fuse_inode *fi = INO_FI(inode);
        struct fuse_conn *fc = INO_FC(inode);

        if (inode->i_ino == FUSE_ROOT_INO) {
                if (!(fc->flags & FUSE_ALLOW_OTHER) &&
                    current->fsuid != fc->uid)
                        return -EACCES;
        } else if (!fi->i_time || time_before_eq(jiffies, fi->i_time))
                return 0;

        return fuse_do_getattr(inode);
}

static int _fuse_permission(struct inode *inode, int mask)
{
        struct fuse_conn *fc = INO_FC(inode);

        if (!(fc->flags & FUSE_ALLOW_OTHER) && current->fsuid != fc->uid)
                return -EACCES;
        else if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
                int err = vfs_permission(inode, mask);

                /* If permission is denied, try to refresh file
                   attributes.  This is also needed, because the root
                   node will at first have no permissions */

                if (err == -EACCES) {
                        err = fuse_do_getattr(inode);
                        if (!err)
                                err = vfs_permission(inode, mask);
                }

                /* FIXME: Need some mechanism to revoke permissions:
                   currently if the filesystem suddenly changes the
                   file mode, we will not be informed abot that, and
                   continue to allow access to the file/directory.
                   
                   This is actually not so grave, since the user can
                   simply keep access to the file/directory anyway by
                   keeping it open... */

                return err;
        } else
                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 > NAME_MAX) {
                        printk("fuse_readdir: name too long\n");
                        return -EPROTO;
                }
                if (reclen > nbytes)
                        break;

                over = filldir(dstbuf, dirent->name, dirent->namelen,
                              file->f_pos, dirent->ino, dirent->type);
                if (over)
                        break;

                buf += reclen;
                file->f_pos += reclen;
                nbytes -= reclen;
        }

        return 0;
}

static int fuse_checkdir(struct file *cfile, struct file *file)
{
        struct inode *inode;
        if (!cfile) {
                printk("fuse_getdir: invalid file\n");
                return -EPROTO;
        }
        inode = cfile->f_dentry->d_inode;
        if (!S_ISREG(inode->i_mode)) {
                printk("fuse_getdir: not a regular file\n");
                fput(cfile);
                return -EPROTO;
        }
        
        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 = INO_FC(inode);
        struct fuse_req *req = fuse_get_request(fc);
        struct fuse_getdir_out_i outarg;
        int err;

        if (!req)
                return -ERESTARTSYS;

        req->in.h.opcode = FUSE_GETDIR;
        req->in.h.ino = inode->i_ino;
        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; 
        if (!err)
                err = fuse_checkdir(outarg.file, file);
        fuse_put_request(fc, req);
        return err;
}

#define DIR_BUFSIZE 2048
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 = kmalloc(DIR_BUFSIZE, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;
        
        ret = kernel_read(cfile, file->f_pos, buf, DIR_BUFSIZE);
        if (ret < 0)
                printk("fuse_readdir: failed to read container file\n");
        else 
                ret = parse_dirfile(buf, ret, file, dstbuf, filldir);

        kfree(buf);     
        return ret;
}

static char *read_link(struct dentry *dentry)
{
        struct inode *inode = dentry->d_inode;
        struct fuse_conn *fc = INO_FC(inode);
        struct fuse_req *req = fuse_get_request(fc);
        char *link;

        if (!req)
                return ERR_PTR(-ERESTARTSYS);

        link = (char *) __get_free_page(GFP_KERNEL);
        if (!link) {
                link = ERR_PTR(-ENOMEM);
                goto out;
        }
        req->in.h.opcode = FUSE_READLINK;
        req->in.h.ino = inode->i_ino;
        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 int fuse_readlink(struct dentry *dentry, char *buffer, int buflen)
{
        int ret;
        char *link;

        link = read_link(dentry);
        ret = vfs_readlink(dentry, buffer, buflen, link);
        free_link(link);
        return ret;
}

static int fuse_follow_link(struct dentry *dentry, struct nameidata *nd)
{
        int ret;
        char *link;

        link = read_link(dentry);
        ret = vfs_follow_link(nd, link);
        free_link(link);
        return ret;
}

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 unsigned int iattr_to_fattr(struct iattr *iattr,
                                   struct fuse_attr *fattr)
{
        unsigned int ivalid = iattr->ia_valid;
        unsigned int fvalid = 0;
        
        memset(fattr, 0, sizeof(*fattr));
        
        if (ivalid & ATTR_MODE)
                fvalid |= FATTR_MODE,   fattr->mode = iattr->ia_mode;
        if (ivalid & ATTR_UID)
                fvalid |= FATTR_UID,    fattr->uid = iattr->ia_uid;
        if (ivalid & ATTR_GID)
                fvalid |= FATTR_GID,    fattr->gid = iattr->ia_gid;
        if (ivalid & ATTR_SIZE)
                fvalid |= FATTR_SIZE,   fattr->size = iattr->ia_size;
        /* You can only _set_ these together (they may change by themselves) */
        if ((ivalid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME)) {
                fvalid |= FATTR_ATIME | FATTR_MTIME;
#ifdef KERNEL_2_6
                fattr->atime = iattr->ia_atime.tv_sec;
                fattr->mtime = iattr->ia_mtime.tv_sec;
#else
                fattr->atime = iattr->ia_atime;
                fattr->mtime = iattr->ia_mtime;
#endif
        }

        return fvalid;
}

static int fuse_setattr(struct dentry *entry, struct iattr *attr)
{
        struct inode *inode = entry->d_inode;
        struct fuse_conn *fc = INO_FC(inode);
        struct fuse_inode *fi = INO_FI(inode);
        struct fuse_req *req;
        struct fuse_setattr_in inarg;
        struct fuse_attr_out outarg;
        int err;
        int is_truncate = 0;
        
        if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
                err = inode_change_ok(inode, attr);
                if (err)
                        return err;
        }

        if (attr->ia_valid & ATTR_SIZE) {
                unsigned long limit;
                is_truncate = 1;

                limit = current->rlim[RLIMIT_FSIZE].rlim_cur;
                if (limit != RLIM_INFINITY && attr->ia_size > limit) {
                        send_sig(SIGXFSZ, current, 0);
                        return -EFBIG;
                }
                //fuse_sync_inode(inode);
        }

        req = fuse_get_request(fc);
        if (!req)
                return -ERESTARTSYS;

        if (is_truncate)
                down_write(&fi->write_sem);

        memset(&inarg, 0, sizeof(inarg));
        inarg.valid = iattr_to_fattr(attr, &inarg.attr);
        req->in.h.opcode = FUSE_SETATTR;
        req->in.h.ino = inode->i_ino;
        req->in.numargs = 1;
        req->in.args[0].size = sizeof(inarg);
        req->in.args[0].value = &inarg;
        req->out.numargs = 1;
        req->out.args[0].size = sizeof(outarg);
        req->out.args[0].value = &outarg;
        request_send(fc, req);
        err = req->out.h.error;
        fuse_put_request(fc, req);

        if (!err) {
                if (is_truncate) {
                        loff_t origsize = i_size_read(inode);
                        i_size_write(inode, outarg.attr.size);
                        up_write(&fi->write_sem);
                        if (origsize > outarg.attr.size)
                                vmtruncate(inode, outarg.attr.size);
                }
                change_attributes(inode, &outarg.attr);
                fi->i_time = time_to_jiffies(outarg.attr_valid,
                                             outarg.attr_valid_nsec);
        } else if (is_truncate)
                up_write(&fi->write_sem);
                
        return err;
}

static int _fuse_dentry_revalidate(struct dentry *entry)
{
        if (!entry->d_inode)
                return 0;
        else if (entry->d_time && time_after(jiffies, entry->d_time)) {
                struct inode *inode = entry->d_inode;
                struct fuse_inode *fi = INO_FI(inode);
                struct fuse_entry_out outarg;
                int version;
                int ret;
                
                ret = fuse_do_lookup(entry->d_parent->d_inode, entry, &outarg,
                                     &version);
                if (ret)
                        return 0;
                
                if (outarg.ino != inode->i_ino)
                        return 0;
                
                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;
}

#ifdef KERNEL_2_6

#define fuse_mknod _fuse_mknod

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);
        return d_splice_alias(inode, entry);
}

static int fuse_create(struct inode *dir, struct dentry *entry, int mode,
                       struct nameidata *nd)
{
        return _fuse_create(dir, entry, mode);
}

static int fuse_permission(struct inode *inode, int mask,
                            struct nameidata *nd)
{
        return _fuse_permission(inode, mask);
}

static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd)
{
        return _fuse_dentry_revalidate(entry);
}

#else /* KERNEL_2_6 */

#define fuse_create _fuse_create
#define fuse_permission _fuse_permission

static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry)
{
        struct inode *inode;
        struct dentry *alias;

        int err = fuse_lookup_iget(dir, entry, &inode);
        if (err)
                return ERR_PTR(err);

        if (inode && S_ISDIR(inode->i_mode) &&
            (alias = d_find_alias(inode)) != NULL) {
                dput(alias);
                iput(inode);
                printk("fuse: cannot assign an existing directory\n");
                return ERR_PTR(-EPROTO);
        }

        d_add(entry, inode);
        return NULL;
}

static int fuse_mknod(struct inode *dir, struct dentry *entry, int mode,
                      int rdev)
{
        return _fuse_mknod(dir, entry, mode, rdev);
}

static int fuse_dentry_revalidate(struct dentry *entry, int flags)
{
        return _fuse_dentry_revalidate(entry);
}
#endif /* KERNEL_2_6 */

#ifdef HAVE_KERNEL_XATTR

#ifdef KERNEL_2_6
static int fuse_setxattr(struct dentry *entry, const char *name,
                         const void *value, size_t size, int flags)
#else
static int fuse_setxattr(struct dentry *entry, const char *name,
                         void *value, size_t size, int flags)
#endif
{
        struct inode *inode = entry->d_inode;
        struct fuse_conn *fc = INO_FC(inode);
        struct fuse_req *req;
        struct fuse_setxattr_in inarg;
        int err;

        if (size > FUSE_XATTR_SIZE_MAX)
                return -E2BIG;

        if (fc->no_setxattr)
                return -EOPNOTSUPP;

        req = fuse_get_request(fc);
        if (!req)
                return -ERESTARTSYS;

        memset(&inarg, 0, sizeof(inarg));
        inarg.size = size;
        inarg.flags = flags;
        req->in.h.opcode = FUSE_SETXATTR;
        req->in.h.ino = inode->i_ino;
        req->in.numargs = 3;
        req->in.args[0].size = sizeof(inarg);
        req->in.args[0].value = &inarg;
        req->in.args[1].size = strlen(name) + 1;
        req->in.args[1].value = name;
        req->in.args[2].size = size;
        req->in.args[2].value = value;
        request_send(fc, req);
        err = req->out.h.error;
        if (err == -ENOSYS) {
                fc->no_setxattr = 1;
                err = -EOPNOTSUPP;
        }
        fuse_put_request(fc, req);
        return err;
}

static ssize_t fuse_getxattr(struct dentry *entry, const char *name,
                             void *value, size_t size)
{
        struct inode *inode = entry->d_inode;
        struct fuse_conn *fc = INO_FC(inode);
        struct fuse_req *req;
        struct fuse_getxattr_in inarg;
        struct fuse_getxattr_out outarg;
        ssize_t ret;

        if (fc->no_getxattr)
                return -EOPNOTSUPP;

        req = fuse_get_request(fc);
        if (!req)
                return -ERESTARTSYS;

        memset(&inarg, 0, sizeof(inarg));
        inarg.size = size;
        req->in.h.opcode = FUSE_GETXATTR;
        req->in.h.ino = inode->i_ino;
        req->in.numargs = 2;
        req->in.args[0].size = sizeof(inarg);
        req->in.args[0].value = &inarg;
        req->in.args[1].size = strlen(name) + 1;
        req->in.args[1].value = name;
        /* This is really two different operations rolled into one */
        req->out.numargs = 1;
        if (size) {
                req->out.argvar = 1;
                req->out.args[0].size = size;
                req->out.args[0].value = value;
        } else {
                req->out.args[0].size = sizeof(outarg);
                req->out.args[0].value = &outarg;
        }
        request_send(fc, req);
        ret = req->out.h.error;
        if (!ret)
                ret = size ? req->out.args[0].size : outarg.size;
        else {
                if (ret == -ENOSYS) {
                        fc->no_getxattr = 1;
                        ret = -EOPNOTSUPP;
                }
        }
        fuse_put_request(fc, req);
        return ret;
}

static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size)
{
        struct inode *inode = entry->d_inode;
        struct fuse_conn *fc = INO_FC(inode);
        struct fuse_req *req;
        struct fuse_getxattr_in inarg;
        struct fuse_getxattr_out outarg;
        ssize_t ret;

        if (fc->no_listxattr)
                return -EOPNOTSUPP;

        req = fuse_get_request(fc);
        if (!req)
                return -ERESTARTSYS;

        memset(&inarg, 0, sizeof(inarg));
        inarg.size = size;
        req->in.h.opcode = FUSE_LISTXATTR;
        req->in.h.ino = inode->i_ino;
        req->in.numargs = 1;
        req->in.args[0].size = sizeof(inarg);
        req->in.args[0].value = &inarg;
        /* This is really two different operations rolled into one */
        req->out.numargs = 1;
        if (size) {
                req->out.argvar = 1;
                req->out.args[0].size = size;
                req->out.args[0].value = list;
        } else {
                req->out.args[0].size = sizeof(outarg);
                req->out.args[0].value = &outarg;
        }
        request_send(fc, req);
        ret = req->out.h.error;
        if (!ret)
                ret = size ? req->out.args[0].size : outarg.size;
        else {
                if (ret == -ENOSYS) {
                        fc->no_listxattr = 1;
                        ret = -EOPNOTSUPP;
                }
        }
        fuse_put_request(fc, req);
        return ret;
}

static int fuse_removexattr(struct dentry *entry, const char *name)
{
        struct inode *inode = entry->d_inode;
        struct fuse_conn *fc = INO_FC(inode);
        struct fuse_req *req;
        int err;
        
        if (fc->no_removexattr)
                return -EOPNOTSUPP;

        req = fuse_get_request(fc);
        if (!req)
                return -ERESTARTSYS;

        req->in.h.opcode = FUSE_REMOVEXATTR;
        req->in.h.ino = inode->i_ino;
        req->in.numargs = 1;
        req->in.args[0].size = strlen(name) + 1;
        req->in.args[0].value = name;
        request_send(fc, req);
        err = req->out.h.error;
        if (err == -ENOSYS) {
                fc->no_removexattr = 1;
                err = -EOPNOTSUPP;
        }
        fuse_put_request(fc, req);
        return err;
}

#endif

static struct inode_operations fuse_dir_inode_operations =
{
        .lookup         = fuse_lookup,
        .create         = fuse_create,
        .mknod          = fuse_mknod,
        .mkdir          = fuse_mkdir,
        .symlink        = fuse_symlink,
        .unlink         = fuse_unlink,
        .rmdir          = fuse_rmdir,
        .rename         = fuse_rename,
        .link           = fuse_link,
        .setattr        = fuse_setattr,
        .permission     = fuse_permission,
#ifdef KERNEL_2_6
        .getattr        = fuse_getattr,
#else
        .revalidate     = fuse_revalidate,
#endif
#ifdef HAVE_KERNEL_XATTR
        .setxattr       = fuse_setxattr,
        .getxattr       = fuse_getxattr,
        .listxattr      = fuse_listxattr,
        .removexattr    = fuse_removexattr,
#endif
};

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_file_inode_operations = {
        .setattr        = fuse_setattr,
        .permission     = fuse_permission,
#ifdef KERNEL_2_6
        .getattr        = fuse_getattr,
#else
        .revalidate     = fuse_revalidate,
#endif
#ifdef HAVE_KERNEL_XATTR
        .setxattr       = fuse_setxattr,
        .getxattr       = fuse_getxattr,
        .listxattr      = fuse_listxattr,
        .removexattr    = fuse_removexattr,
#endif
};

static struct inode_operations fuse_symlink_inode_operations =
{
        .setattr        = fuse_setattr,
        .readlink       = fuse_readlink,
        .follow_link    = fuse_follow_link,
#ifdef KERNEL_2_6
        .getattr        = fuse_getattr,
#else
        .revalidate     = fuse_revalidate,
#endif
#ifdef HAVE_KERNEL_XATTR
        .setxattr       = fuse_setxattr,
        .getxattr       = fuse_getxattr,
        .listxattr      = fuse_listxattr,
        .removexattr    = fuse_removexattr,
#endif
};

static struct dentry_operations fuse_dentry_operations = {
        .d_revalidate   = fuse_dentry_revalidate,
};

/* 
 * Local Variables:
 * indent-tabs-mode: t
 * c-basic-offset: 8
 * End:
 */