| /* |
| FUSE: Filesystem in Userspace |
| Copyright (C) 2001-2008 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/sched.h> |
| #include <linux/namei.h> |
| #include <linux/slab.h> |
| #include <linux/xattr.h> |
| #include <linux/posix_acl.h> |
| |
| static bool fuse_use_readdirplus(struct inode *dir, struct dir_context *ctx) |
| { |
| struct fuse_conn *fc = get_fuse_conn(dir); |
| struct fuse_inode *fi = get_fuse_inode(dir); |
| |
| if (!fc->do_readdirplus) |
| return false; |
| if (!fc->readdirplus_auto) |
| return true; |
| if (test_and_clear_bit(FUSE_I_ADVISE_RDPLUS, &fi->state)) |
| return true; |
| if (ctx->pos == 0) |
| return true; |
| return false; |
| } |
| |
| static void fuse_advise_use_readdirplus(struct inode *dir) |
| { |
| struct fuse_inode *fi = get_fuse_inode(dir); |
| |
| set_bit(FUSE_I_ADVISE_RDPLUS, &fi->state); |
| } |
| |
| union fuse_dentry { |
| u64 time; |
| struct rcu_head rcu; |
| }; |
| |
| static inline void fuse_dentry_settime(struct dentry *entry, u64 time) |
| { |
| ((union fuse_dentry *) entry->d_fsdata)->time = time; |
| } |
| |
| static inline u64 fuse_dentry_time(struct dentry *entry) |
| { |
| return ((union fuse_dentry *) entry->d_fsdata)->time; |
| } |
| |
| /* |
| * FUSE caches dentries and attributes with separate timeout. The |
| * time in jiffies until the dentry/attributes are valid is stored in |
| * dentry->d_fsdata and fuse_inode->i_time respectively. |
| */ |
| |
| /* |
| * Calculate the time in jiffies until a dentry/attributes are valid |
| */ |
| static u64 time_to_jiffies(u64 sec, u32 nsec) |
| { |
| if (sec || nsec) { |
| struct timespec64 ts = { |
| sec, |
| min_t(u32, nsec, NSEC_PER_SEC - 1) |
| }; |
| |
| return get_jiffies_64() + timespec64_to_jiffies(&ts); |
| } else |
| return 0; |
| } |
| |
| /* |
| * Set dentry and possibly attribute timeouts from the lookup/mk* |
| * replies |
| */ |
| static void fuse_change_entry_timeout(struct dentry *entry, |
| struct fuse_entry_out *o) |
| { |
| fuse_dentry_settime(entry, |
| time_to_jiffies(o->entry_valid, o->entry_valid_nsec)); |
| } |
| |
| static u64 attr_timeout(struct fuse_attr_out *o) |
| { |
| return time_to_jiffies(o->attr_valid, o->attr_valid_nsec); |
| } |
| |
| static u64 entry_attr_timeout(struct fuse_entry_out *o) |
| { |
| return time_to_jiffies(o->attr_valid, o->attr_valid_nsec); |
| } |
| |
| /* |
| * Mark the attributes as stale, so that at the next call to |
| * ->getattr() they will be fetched from userspace |
| */ |
| void fuse_invalidate_attr(struct inode *inode) |
| { |
| get_fuse_inode(inode)->i_time = 0; |
| } |
| |
| /** |
| * Mark the attributes as stale due to an atime change. Avoid the invalidate if |
| * atime is not used. |
| */ |
| void fuse_invalidate_atime(struct inode *inode) |
| { |
| if (!IS_RDONLY(inode)) |
| fuse_invalidate_attr(inode); |
| } |
| |
| /* |
| * Just mark the entry as stale, so that a next attempt to look it up |
| * will result in a new lookup call to userspace |
| * |
| * This is called when a dentry is about to become negative and the |
| * timeout is unknown (unlink, rmdir, rename and in some cases |
| * lookup) |
| */ |
| void fuse_invalidate_entry_cache(struct dentry *entry) |
| { |
| fuse_dentry_settime(entry, 0); |
| } |
| |
| /* |
| * Same as fuse_invalidate_entry_cache(), but also try to remove the |
| * dentry from the hash |
| */ |
| static void fuse_invalidate_entry(struct dentry *entry) |
| { |
| d_invalidate(entry); |
| fuse_invalidate_entry_cache(entry); |
| } |
| |
| static void fuse_lookup_init(struct fuse_conn *fc, struct fuse_args *args, |
| u64 nodeid, const struct qstr *name, |
| struct fuse_entry_out *outarg) |
| { |
| memset(outarg, 0, sizeof(struct fuse_entry_out)); |
| args->in.h.opcode = FUSE_LOOKUP; |
| args->in.h.nodeid = nodeid; |
| args->in.numargs = 1; |
| args->in.args[0].size = name->len + 1; |
| args->in.args[0].value = name->name; |
| args->out.numargs = 1; |
| args->out.args[0].size = sizeof(struct fuse_entry_out); |
| args->out.args[0].value = outarg; |
| } |
| |
| u64 fuse_get_attr_version(struct fuse_conn *fc) |
| { |
| u64 curr_version; |
| |
| /* |
| * The spin lock isn't actually needed on 64bit archs, but we |
| * don't yet care too much about such optimizations. |
| */ |
| spin_lock(&fc->lock); |
| curr_version = fc->attr_version; |
| spin_unlock(&fc->lock); |
| |
| return curr_version; |
| } |
| |
| /* |
| * Check whether the dentry is still valid |
| * |
| * If the entry validity timeout has expired and the dentry is |
| * positive, try to redo the lookup. If the lookup results in a |
| * different inode, then let the VFS invalidate the dentry and redo |
| * the lookup once more. If the lookup results in the same inode, |
| * then refresh the attributes, timeouts and mark the dentry valid. |
| */ |
| static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags) |
| { |
| struct inode *inode; |
| struct dentry *parent; |
| struct fuse_conn *fc; |
| struct fuse_inode *fi; |
| int ret; |
| |
| inode = d_inode_rcu(entry); |
| if (inode && is_bad_inode(inode)) |
| goto invalid; |
| else if (time_before64(fuse_dentry_time(entry), get_jiffies_64()) || |
| (flags & LOOKUP_REVAL)) { |
| struct fuse_entry_out outarg; |
| FUSE_ARGS(args); |
| struct fuse_forget_link *forget; |
| u64 attr_version; |
| |
| /* For negative dentries, always do a fresh lookup */ |
| if (!inode) |
| goto invalid; |
| |
| ret = -ECHILD; |
| if (flags & LOOKUP_RCU) |
| goto out; |
| |
| fc = get_fuse_conn(inode); |
| |
| forget = fuse_alloc_forget(); |
| ret = -ENOMEM; |
| if (!forget) |
| goto out; |
| |
| attr_version = fuse_get_attr_version(fc); |
| |
| parent = dget_parent(entry); |
| fuse_lookup_init(fc, &args, get_node_id(d_inode(parent)), |
| &entry->d_name, &outarg); |
| ret = fuse_simple_request(fc, &args); |
| dput(parent); |
| /* Zero nodeid is same as -ENOENT */ |
| if (!ret && !outarg.nodeid) |
| ret = -ENOENT; |
| if (!ret) { |
| fi = get_fuse_inode(inode); |
| if (outarg.nodeid != get_node_id(inode)) { |
| fuse_queue_forget(fc, forget, outarg.nodeid, 1); |
| goto invalid; |
| } |
| spin_lock(&fc->lock); |
| fi->nlookup++; |
| spin_unlock(&fc->lock); |
| } |
| kfree(forget); |
| if (ret == -ENOMEM) |
| goto out; |
| if (ret || (outarg.attr.mode ^ inode->i_mode) & S_IFMT) |
| goto invalid; |
| |
| forget_all_cached_acls(inode); |
| fuse_change_attributes(inode, &outarg.attr, |
| entry_attr_timeout(&outarg), |
| attr_version); |
| fuse_change_entry_timeout(entry, &outarg); |
| } else if (inode) { |
| fi = get_fuse_inode(inode); |
| if (flags & LOOKUP_RCU) { |
| if (test_bit(FUSE_I_INIT_RDPLUS, &fi->state)) |
| return -ECHILD; |
| } else if (test_and_clear_bit(FUSE_I_INIT_RDPLUS, &fi->state)) { |
| parent = dget_parent(entry); |
| fuse_advise_use_readdirplus(d_inode(parent)); |
| dput(parent); |
| } |
| } |
| ret = 1; |
| out: |
| return ret; |
| |
| invalid: |
| ret = 0; |
| goto out; |
| } |
| |
| static int invalid_nodeid(u64 nodeid) |
| { |
| return !nodeid || nodeid == FUSE_ROOT_ID; |
| } |
| |
| static int fuse_dentry_init(struct dentry *dentry) |
| { |
| dentry->d_fsdata = kzalloc(sizeof(union fuse_dentry), GFP_KERNEL); |
| |
| return dentry->d_fsdata ? 0 : -ENOMEM; |
| } |
| static void fuse_dentry_release(struct dentry *dentry) |
| { |
| union fuse_dentry *fd = dentry->d_fsdata; |
| |
| kfree_rcu(fd, rcu); |
| } |
| |
| const struct dentry_operations fuse_dentry_operations = { |
| .d_revalidate = fuse_dentry_revalidate, |
| .d_init = fuse_dentry_init, |
| .d_release = fuse_dentry_release, |
| }; |
| |
| const struct dentry_operations fuse_root_dentry_operations = { |
| .d_init = fuse_dentry_init, |
| .d_release = fuse_dentry_release, |
| }; |
| |
| int fuse_valid_type(int m) |
| { |
| return S_ISREG(m) || S_ISDIR(m) || S_ISLNK(m) || S_ISCHR(m) || |
| S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m); |
| } |
| |
| int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name, |
| struct fuse_entry_out *outarg, struct inode **inode) |
| { |
| struct fuse_conn *fc = get_fuse_conn_super(sb); |
| FUSE_ARGS(args); |
| struct fuse_forget_link *forget; |
| u64 attr_version; |
| int err; |
| |
| *inode = NULL; |
| err = -ENAMETOOLONG; |
| if (name->len > FUSE_NAME_MAX) |
| goto out; |
| |
| |
| forget = fuse_alloc_forget(); |
| err = -ENOMEM; |
| if (!forget) |
| goto out; |
| |
| attr_version = fuse_get_attr_version(fc); |
| |
| fuse_lookup_init(fc, &args, nodeid, name, outarg); |
| err = fuse_simple_request(fc, &args); |
| /* Zero nodeid is same as -ENOENT, but with valid timeout */ |
| if (err || !outarg->nodeid) |
| goto out_put_forget; |
| |
| err = -EIO; |
| if (!outarg->nodeid) |
| goto out_put_forget; |
| if (!fuse_valid_type(outarg->attr.mode)) |
| goto out_put_forget; |
| |
| *inode = fuse_iget(sb, outarg->nodeid, outarg->generation, |
| &outarg->attr, entry_attr_timeout(outarg), |
| attr_version); |
| err = -ENOMEM; |
| if (!*inode) { |
| fuse_queue_forget(fc, forget, outarg->nodeid, 1); |
| goto out; |
| } |
| err = 0; |
| |
| out_put_forget: |
| kfree(forget); |
| out: |
| return err; |
| } |
| |
| static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, |
| unsigned int flags) |
| { |
| int err; |
| struct fuse_entry_out outarg; |
| struct inode *inode; |
| struct dentry *newent; |
| bool outarg_valid = true; |
| |
| fuse_lock_inode(dir); |
| err = fuse_lookup_name(dir->i_sb, get_node_id(dir), &entry->d_name, |
| &outarg, &inode); |
| fuse_unlock_inode(dir); |
| if (err == -ENOENT) { |
| outarg_valid = false; |
| err = 0; |
| } |
| if (err) |
| goto out_err; |
| |
| err = -EIO; |
| if (inode && get_node_id(inode) == FUSE_ROOT_ID) |
| goto out_iput; |
| |
| newent = d_splice_alias(inode, entry); |
| err = PTR_ERR(newent); |
| if (IS_ERR(newent)) |
| goto out_err; |
| |
| entry = newent ? newent : entry; |
| if (outarg_valid) |
| fuse_change_entry_timeout(entry, &outarg); |
| else |
| fuse_invalidate_entry_cache(entry); |
| |
| fuse_advise_use_readdirplus(dir); |
| return newent; |
| |
| out_iput: |
| iput(inode); |
| out_err: |
| return ERR_PTR(err); |
| } |
| |
| /* |
| * Atomic create+open operation |
| * |
| * If the filesystem doesn't support this, then fall back to separate |
| * 'mknod' + 'open' requests. |
| */ |
| static int fuse_create_open(struct inode *dir, struct dentry *entry, |
| struct file *file, unsigned flags, |
| umode_t mode, int *opened) |
| { |
| int err; |
| struct inode *inode; |
| struct fuse_conn *fc = get_fuse_conn(dir); |
| FUSE_ARGS(args); |
| struct fuse_forget_link *forget; |
| struct fuse_create_in inarg; |
| struct fuse_open_out outopen; |
| struct fuse_entry_out outentry; |
| struct fuse_file *ff; |
| |
| /* Userspace expects S_IFREG in create mode */ |
| BUG_ON((mode & S_IFMT) != S_IFREG); |
| |
| forget = fuse_alloc_forget(); |
| err = -ENOMEM; |
| if (!forget) |
| goto out_err; |
| |
| err = -ENOMEM; |
| ff = fuse_file_alloc(fc); |
| if (!ff) |
| goto out_put_forget_req; |
| |
| if (!fc->dont_mask) |
| mode &= ~current_umask(); |
| |
| flags &= ~O_NOCTTY; |
| memset(&inarg, 0, sizeof(inarg)); |
| memset(&outentry, 0, sizeof(outentry)); |
| inarg.flags = flags; |
| inarg.mode = mode; |
| inarg.umask = current_umask(); |
| args.in.h.opcode = FUSE_CREATE; |
| args.in.h.nodeid = get_node_id(dir); |
| args.in.numargs = 2; |
| args.in.args[0].size = sizeof(inarg); |
| args.in.args[0].value = &inarg; |
| args.in.args[1].size = entry->d_name.len + 1; |
| args.in.args[1].value = entry->d_name.name; |
| args.out.numargs = 2; |
| args.out.args[0].size = sizeof(outentry); |
| args.out.args[0].value = &outentry; |
| args.out.args[1].size = sizeof(outopen); |
| args.out.args[1].value = &outopen; |
| err = fuse_simple_request(fc, &args); |
| if (err) |
| goto out_free_ff; |
| |
| err = -EIO; |
| if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid)) |
| goto out_free_ff; |
| |
| ff->fh = outopen.fh; |
| ff->nodeid = outentry.nodeid; |
| ff->open_flags = outopen.open_flags; |
| inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation, |
| &outentry.attr, entry_attr_timeout(&outentry), 0); |
| if (!inode) { |
| flags &= ~(O_CREAT | O_EXCL | O_TRUNC); |
| fuse_sync_release(ff, flags); |
| fuse_queue_forget(fc, forget, outentry.nodeid, 1); |
| err = -ENOMEM; |
| goto out_err; |
| } |
| kfree(forget); |
| d_instantiate(entry, inode); |
| fuse_change_entry_timeout(entry, &outentry); |
| fuse_invalidate_attr(dir); |
| err = finish_open(file, entry, generic_file_open); |
| if (err) { |
| fuse_sync_release(ff, flags); |
| } else { |
| file->private_data = ff; |
| fuse_finish_open(inode, file); |
| } |
| return err; |
| |
| out_free_ff: |
| fuse_file_free(ff); |
| out_put_forget_req: |
| kfree(forget); |
| out_err: |
| return err; |
| } |
| |
| static int fuse_mknod(struct inode *, struct dentry *, umode_t, dev_t); |
| static int fuse_atomic_open(struct inode *dir, struct dentry *entry, |
| struct file *file, unsigned flags, |
| umode_t mode, int *opened) |
| { |
| int err; |
| struct fuse_conn *fc = get_fuse_conn(dir); |
| struct dentry *res = NULL; |
| |
| if (d_in_lookup(entry)) { |
| res = fuse_lookup(dir, entry, 0); |
| if (IS_ERR(res)) |
| return PTR_ERR(res); |
| |
| if (res) |
| entry = res; |
| } |
| |
| if (!(flags & O_CREAT) || d_really_is_positive(entry)) |
| goto no_open; |
| |
| /* Only creates */ |
| file->f_mode |= FMODE_CREATED; |
| |
| if (fc->no_create) |
| goto mknod; |
| |
| err = fuse_create_open(dir, entry, file, flags, mode, opened); |
| if (err == -ENOSYS) { |
| fc->no_create = 1; |
| goto mknod; |
| } |
| out_dput: |
| dput(res); |
| return err; |
| |
| mknod: |
| err = fuse_mknod(dir, entry, mode, 0); |
| if (err) |
| goto out_dput; |
| no_open: |
| return finish_no_open(file, res); |
| } |
| |
| /* |
| * Code shared between mknod, mkdir, symlink and link |
| */ |
| static int create_new_entry(struct fuse_conn *fc, struct fuse_args *args, |
| struct inode *dir, struct dentry *entry, |
| umode_t mode) |
| { |
| struct fuse_entry_out outarg; |
| struct inode *inode; |
| int err; |
| struct fuse_forget_link *forget; |
| |
| forget = fuse_alloc_forget(); |
| if (!forget) |
| return -ENOMEM; |
| |
| memset(&outarg, 0, sizeof(outarg)); |
| args->in.h.nodeid = get_node_id(dir); |
| args->out.numargs = 1; |
| args->out.args[0].size = sizeof(outarg); |
| args->out.args[0].value = &outarg; |
| err = fuse_simple_request(fc, args); |
| if (err) |
| goto out_put_forget_req; |
| |
| err = -EIO; |
| if (invalid_nodeid(outarg.nodeid)) |
| goto out_put_forget_req; |
| |
| if ((outarg.attr.mode ^ mode) & S_IFMT) |
| goto out_put_forget_req; |
| |
| inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation, |
| &outarg.attr, entry_attr_timeout(&outarg), 0); |
| if (!inode) { |
| fuse_queue_forget(fc, forget, outarg.nodeid, 1); |
| return -ENOMEM; |
| } |
| kfree(forget); |
| |
| err = d_instantiate_no_diralias(entry, inode); |
| if (err) |
| return err; |
| |
| fuse_change_entry_timeout(entry, &outarg); |
| fuse_invalidate_attr(dir); |
| return 0; |
| |
| out_put_forget_req: |
| kfree(forget); |
| return err; |
| } |
| |
| static int fuse_mknod(struct inode *dir, struct dentry *entry, umode_t mode, |
| dev_t rdev) |
| { |
| struct fuse_mknod_in inarg; |
| struct fuse_conn *fc = get_fuse_conn(dir); |
| FUSE_ARGS(args); |
| |
| if (!fc->dont_mask) |
| mode &= ~current_umask(); |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.mode = mode; |
| inarg.rdev = new_encode_dev(rdev); |
| inarg.umask = current_umask(); |
| args.in.h.opcode = FUSE_MKNOD; |
| args.in.numargs = 2; |
| args.in.args[0].size = sizeof(inarg); |
| args.in.args[0].value = &inarg; |
| args.in.args[1].size = entry->d_name.len + 1; |
| args.in.args[1].value = entry->d_name.name; |
| return create_new_entry(fc, &args, dir, entry, mode); |
| } |
| |
| static int fuse_create(struct inode *dir, struct dentry *entry, umode_t mode, |
| bool excl) |
| { |
| return fuse_mknod(dir, entry, mode, 0); |
| } |
| |
| static int fuse_mkdir(struct inode *dir, struct dentry *entry, umode_t mode) |
| { |
| struct fuse_mkdir_in inarg; |
| struct fuse_conn *fc = get_fuse_conn(dir); |
| FUSE_ARGS(args); |
| |
| if (!fc->dont_mask) |
| mode &= ~current_umask(); |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.mode = mode; |
| inarg.umask = current_umask(); |
| args.in.h.opcode = FUSE_MKDIR; |
| args.in.numargs = 2; |
| args.in.args[0].size = sizeof(inarg); |
| args.in.args[0].value = &inarg; |
| args.in.args[1].size = entry->d_name.len + 1; |
| args.in.args[1].value = entry->d_name.name; |
| return create_new_entry(fc, &args, dir, entry, S_IFDIR); |
| } |
| |
| static int fuse_symlink(struct inode *dir, struct dentry *entry, |
| const char *link) |
| { |
| struct fuse_conn *fc = get_fuse_conn(dir); |
| unsigned len = strlen(link) + 1; |
| FUSE_ARGS(args); |
| |
| args.in.h.opcode = FUSE_SYMLINK; |
| args.in.numargs = 2; |
| args.in.args[0].size = entry->d_name.len + 1; |
| args.in.args[0].value = entry->d_name.name; |
| args.in.args[1].size = len; |
| args.in.args[1].value = link; |
| return create_new_entry(fc, &args, dir, entry, S_IFLNK); |
| } |
| |
| void fuse_update_ctime(struct inode *inode) |
| { |
| if (!IS_NOCMTIME(inode)) { |
| inode->i_ctime = current_time(inode); |
| mark_inode_dirty_sync(inode); |
| } |
| } |
| |
| static int fuse_unlink(struct inode *dir, struct dentry *entry) |
| { |
| int err; |
| struct fuse_conn *fc = get_fuse_conn(dir); |
| FUSE_ARGS(args); |
| |
| args.in.h.opcode = FUSE_UNLINK; |
| args.in.h.nodeid = get_node_id(dir); |
| args.in.numargs = 1; |
| args.in.args[0].size = entry->d_name.len + 1; |
| args.in.args[0].value = entry->d_name.name; |
| err = fuse_simple_request(fc, &args); |
| if (!err) { |
| struct inode *inode = d_inode(entry); |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| |
| spin_lock(&fc->lock); |
| fi->attr_version = ++fc->attr_version; |
| /* |
| * If i_nlink == 0 then unlink doesn't make sense, yet this can |
| * happen if userspace filesystem is careless. It would be |
| * difficult to enforce correct nlink usage so just ignore this |
| * condition here |
| */ |
| if (inode->i_nlink > 0) |
| drop_nlink(inode); |
| spin_unlock(&fc->lock); |
| fuse_invalidate_attr(inode); |
| fuse_invalidate_attr(dir); |
| fuse_invalidate_entry_cache(entry); |
| fuse_update_ctime(inode); |
| } else if (err == -EINTR) |
| fuse_invalidate_entry(entry); |
| return err; |
| } |
| |
| static int fuse_rmdir(struct inode *dir, struct dentry *entry) |
| { |
| int err; |
| struct fuse_conn *fc = get_fuse_conn(dir); |
| FUSE_ARGS(args); |
| |
| args.in.h.opcode = FUSE_RMDIR; |
| args.in.h.nodeid = get_node_id(dir); |
| args.in.numargs = 1; |
| args.in.args[0].size = entry->d_name.len + 1; |
| args.in.args[0].value = entry->d_name.name; |
| err = fuse_simple_request(fc, &args); |
| if (!err) { |
| clear_nlink(d_inode(entry)); |
| fuse_invalidate_attr(dir); |
| fuse_invalidate_entry_cache(entry); |
| } else if (err == -EINTR) |
| fuse_invalidate_entry(entry); |
| return err; |
| } |
| |
| static int fuse_rename_common(struct inode *olddir, struct dentry *oldent, |
| struct inode *newdir, struct dentry *newent, |
| unsigned int flags, int opcode, size_t argsize) |
| { |
| int err; |
| struct fuse_rename2_in inarg; |
| struct fuse_conn *fc = get_fuse_conn(olddir); |
| FUSE_ARGS(args); |
| |
| memset(&inarg, 0, argsize); |
| inarg.newdir = get_node_id(newdir); |
| inarg.flags = flags; |
| args.in.h.opcode = opcode; |
| args.in.h.nodeid = get_node_id(olddir); |
| args.in.numargs = 3; |
| args.in.args[0].size = argsize; |
| args.in.args[0].value = &inarg; |
| args.in.args[1].size = oldent->d_name.len + 1; |
| args.in.args[1].value = oldent->d_name.name; |
| args.in.args[2].size = newent->d_name.len + 1; |
| args.in.args[2].value = newent->d_name.name; |
| err = fuse_simple_request(fc, &args); |
| if (!err) { |
| /* ctime changes */ |
| fuse_invalidate_attr(d_inode(oldent)); |
| fuse_update_ctime(d_inode(oldent)); |
| |
| if (flags & RENAME_EXCHANGE) { |
| fuse_invalidate_attr(d_inode(newent)); |
| fuse_update_ctime(d_inode(newent)); |
| } |
| |
| fuse_invalidate_attr(olddir); |
| if (olddir != newdir) |
| fuse_invalidate_attr(newdir); |
| |
| /* newent will end up negative */ |
| if (!(flags & RENAME_EXCHANGE) && d_really_is_positive(newent)) { |
| fuse_invalidate_attr(d_inode(newent)); |
| fuse_invalidate_entry_cache(newent); |
| fuse_update_ctime(d_inode(newent)); |
| } |
| } else if (err == -EINTR) { |
| /* If request was interrupted, DEITY only knows if the |
| rename actually took place. If the invalidation |
| fails (e.g. some process has CWD under the renamed |
| directory), then there can be inconsistency between |
| the dcache and the real filesystem. Tough luck. */ |
| fuse_invalidate_entry(oldent); |
| if (d_really_is_positive(newent)) |
| fuse_invalidate_entry(newent); |
| } |
| |
| return err; |
| } |
| |
| static int fuse_rename2(struct inode *olddir, struct dentry *oldent, |
| struct inode *newdir, struct dentry *newent, |
| unsigned int flags) |
| { |
| struct fuse_conn *fc = get_fuse_conn(olddir); |
| int err; |
| |
| if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE)) |
| return -EINVAL; |
| |
| if (flags) { |
| if (fc->no_rename2 || fc->minor < 23) |
| return -EINVAL; |
| |
| err = fuse_rename_common(olddir, oldent, newdir, newent, flags, |
| FUSE_RENAME2, |
| sizeof(struct fuse_rename2_in)); |
| if (err == -ENOSYS) { |
| fc->no_rename2 = 1; |
| err = -EINVAL; |
| } |
| } else { |
| err = fuse_rename_common(olddir, oldent, newdir, newent, 0, |
| FUSE_RENAME, |
| sizeof(struct fuse_rename_in)); |
| } |
| |
| return err; |
| } |
| |
| static int fuse_link(struct dentry *entry, struct inode *newdir, |
| struct dentry *newent) |
| { |
| int err; |
| struct fuse_link_in inarg; |
| struct inode *inode = d_inode(entry); |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| FUSE_ARGS(args); |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.oldnodeid = get_node_id(inode); |
| args.in.h.opcode = FUSE_LINK; |
| args.in.numargs = 2; |
| args.in.args[0].size = sizeof(inarg); |
| args.in.args[0].value = &inarg; |
| args.in.args[1].size = newent->d_name.len + 1; |
| args.in.args[1].value = newent->d_name.name; |
| err = create_new_entry(fc, &args, newdir, newent, inode->i_mode); |
| /* Contrary to "normal" filesystems it can happen that link |
| makes two "logical" inodes point to the same "physical" |
| inode. We invalidate the attributes of the old one, so it |
| will reflect changes in the backing inode (link count, |
| etc.) |
| */ |
| if (!err) { |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| |
| spin_lock(&fc->lock); |
| fi->attr_version = ++fc->attr_version; |
| inc_nlink(inode); |
| spin_unlock(&fc->lock); |
| fuse_invalidate_attr(inode); |
| fuse_update_ctime(inode); |
| } else if (err == -EINTR) { |
| fuse_invalidate_attr(inode); |
| } |
| return err; |
| } |
| |
| static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr, |
| struct kstat *stat) |
| { |
| unsigned int blkbits; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| |
| /* see the comment in fuse_change_attributes() */ |
| if (fc->writeback_cache && S_ISREG(inode->i_mode)) { |
| attr->size = i_size_read(inode); |
| attr->mtime = inode->i_mtime.tv_sec; |
| attr->mtimensec = inode->i_mtime.tv_nsec; |
| attr->ctime = inode->i_ctime.tv_sec; |
| attr->ctimensec = inode->i_ctime.tv_nsec; |
| } |
| |
| stat->dev = inode->i_sb->s_dev; |
| stat->ino = attr->ino; |
| stat->mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777); |
| stat->nlink = attr->nlink; |
| stat->uid = make_kuid(fc->user_ns, attr->uid); |
| stat->gid = make_kgid(fc->user_ns, attr->gid); |
| stat->rdev = inode->i_rdev; |
| stat->atime.tv_sec = attr->atime; |
| stat->atime.tv_nsec = attr->atimensec; |
| stat->mtime.tv_sec = attr->mtime; |
| stat->mtime.tv_nsec = attr->mtimensec; |
| stat->ctime.tv_sec = attr->ctime; |
| stat->ctime.tv_nsec = attr->ctimensec; |
| stat->size = attr->size; |
| stat->blocks = attr->blocks; |
| |
| if (attr->blksize != 0) |
| blkbits = ilog2(attr->blksize); |
| else |
| blkbits = inode->i_sb->s_blocksize_bits; |
| |
| stat->blksize = 1 << blkbits; |
| } |
| |
| static int fuse_do_getattr(struct inode *inode, struct kstat *stat, |
| struct file *file) |
| { |
| int err; |
| struct fuse_getattr_in inarg; |
| struct fuse_attr_out outarg; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| FUSE_ARGS(args); |
| u64 attr_version; |
| |
| attr_version = fuse_get_attr_version(fc); |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| memset(&outarg, 0, sizeof(outarg)); |
| /* Directories have separate file-handle space */ |
| if (file && S_ISREG(inode->i_mode)) { |
| struct fuse_file *ff = file->private_data; |
| |
| inarg.getattr_flags |= FUSE_GETATTR_FH; |
| inarg.fh = ff->fh; |
| } |
| args.in.h.opcode = FUSE_GETATTR; |
| args.in.h.nodeid = get_node_id(inode); |
| args.in.numargs = 1; |
| args.in.args[0].size = sizeof(inarg); |
| args.in.args[0].value = &inarg; |
| args.out.numargs = 1; |
| args.out.args[0].size = sizeof(outarg); |
| args.out.args[0].value = &outarg; |
| err = fuse_simple_request(fc, &args); |
| if (!err) { |
| if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) { |
| make_bad_inode(inode); |
| err = -EIO; |
| } else { |
| fuse_change_attributes(inode, &outarg.attr, |
| attr_timeout(&outarg), |
| attr_version); |
| if (stat) |
| fuse_fillattr(inode, &outarg.attr, stat); |
| } |
| } |
| return err; |
| } |
| |
| static int fuse_update_get_attr(struct inode *inode, struct file *file, |
| struct kstat *stat, unsigned int flags) |
| { |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| int err = 0; |
| bool sync; |
| |
| if (flags & AT_STATX_FORCE_SYNC) |
| sync = true; |
| else if (flags & AT_STATX_DONT_SYNC) |
| sync = false; |
| else |
| sync = time_before64(fi->i_time, get_jiffies_64()); |
| |
| if (sync) { |
| forget_all_cached_acls(inode); |
| err = fuse_do_getattr(inode, stat, file); |
| } else if (stat) { |
| generic_fillattr(inode, stat); |
| stat->mode = fi->orig_i_mode; |
| stat->ino = fi->orig_ino; |
| } |
| |
| return err; |
| } |
| |
| int fuse_update_attributes(struct inode *inode, struct file *file) |
| { |
| return fuse_update_get_attr(inode, file, NULL, 0); |
| } |
| |
| int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid, |
| u64 child_nodeid, struct qstr *name) |
| { |
| int err = -ENOTDIR; |
| struct inode *parent; |
| struct dentry *dir; |
| struct dentry *entry; |
| |
| parent = ilookup5(sb, parent_nodeid, fuse_inode_eq, &parent_nodeid); |
| if (!parent) |
| return -ENOENT; |
| |
| inode_lock(parent); |
| if (!S_ISDIR(parent->i_mode)) |
| goto unlock; |
| |
| err = -ENOENT; |
| dir = d_find_alias(parent); |
| if (!dir) |
| goto unlock; |
| |
| name->hash = full_name_hash(dir, name->name, name->len); |
| entry = d_lookup(dir, name); |
| dput(dir); |
| if (!entry) |
| goto unlock; |
| |
| fuse_invalidate_attr(parent); |
| fuse_invalidate_entry(entry); |
| |
| if (child_nodeid != 0 && d_really_is_positive(entry)) { |
| inode_lock(d_inode(entry)); |
| if (get_node_id(d_inode(entry)) != child_nodeid) { |
| err = -ENOENT; |
| goto badentry; |
| } |
| if (d_mountpoint(entry)) { |
| err = -EBUSY; |
| goto badentry; |
| } |
| if (d_is_dir(entry)) { |
| shrink_dcache_parent(entry); |
| if (!simple_empty(entry)) { |
| err = -ENOTEMPTY; |
| goto badentry; |
| } |
| d_inode(entry)->i_flags |= S_DEAD; |
| } |
| dont_mount(entry); |
| clear_nlink(d_inode(entry)); |
| err = 0; |
| badentry: |
| inode_unlock(d_inode(entry)); |
| if (!err) |
| d_delete(entry); |
| } else { |
| err = 0; |
| } |
| dput(entry); |
| |
| unlock: |
| inode_unlock(parent); |
| iput(parent); |
| return err; |
| } |
| |
| /* |
| * Calling into a user-controlled filesystem gives the filesystem |
| * daemon ptrace-like capabilities over the current process. This |
| * means, that the filesystem daemon is able to record the exact |
| * filesystem operations performed, and can also control the behavior |
| * of the requester process in otherwise impossible ways. For example |
| * it can delay the operation for arbitrary length of time allowing |
| * DoS against the requester. |
| * |
| * For this reason only those processes can call into the filesystem, |
| * for which the owner of the mount has ptrace privilege. This |
| * excludes processes started by other users, suid or sgid processes. |
| */ |
| int fuse_allow_current_process(struct fuse_conn *fc) |
| { |
| const struct cred *cred; |
| |
| if (fc->allow_other) |
| return current_in_userns(fc->user_ns); |
| |
| cred = current_cred(); |
| if (uid_eq(cred->euid, fc->user_id) && |
| uid_eq(cred->suid, fc->user_id) && |
| uid_eq(cred->uid, fc->user_id) && |
| gid_eq(cred->egid, fc->group_id) && |
| gid_eq(cred->sgid, fc->group_id) && |
| gid_eq(cred->gid, fc->group_id)) |
| return 1; |
| |
| return 0; |
| } |
| |
| static int fuse_access(struct inode *inode, int mask) |
| { |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| FUSE_ARGS(args); |
| struct fuse_access_in inarg; |
| int err; |
| |
| BUG_ON(mask & MAY_NOT_BLOCK); |
| |
| if (fc->no_access) |
| return 0; |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.mask = mask & (MAY_READ | MAY_WRITE | MAY_EXEC); |
| args.in.h.opcode = FUSE_ACCESS; |
| args.in.h.nodeid = get_node_id(inode); |
| args.in.numargs = 1; |
| args.in.args[0].size = sizeof(inarg); |
| args.in.args[0].value = &inarg; |
| err = fuse_simple_request(fc, &args); |
| if (err == -ENOSYS) { |
| fc->no_access = 1; |
| err = 0; |
| } |
| return err; |
| } |
| |
| static int fuse_perm_getattr(struct inode *inode, int mask) |
| { |
| if (mask & MAY_NOT_BLOCK) |
| return -ECHILD; |
| |
| forget_all_cached_acls(inode); |
| return fuse_do_getattr(inode, NULL, NULL); |
| } |
| |
| /* |
| * Check permission. The two basic access models of FUSE are: |
| * |
| * 1) Local access checking ('default_permissions' mount option) based |
| * on file mode. This is the plain old disk filesystem permission |
| * modell. |
| * |
| * 2) "Remote" access checking, where server is responsible for |
| * checking permission in each inode operation. An exception to this |
| * is if ->permission() was invoked from sys_access() in which case an |
| * access request is sent. Execute permission is still checked |
| * locally based on file mode. |
| */ |
| static int fuse_permission(struct inode *inode, int mask) |
| { |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| bool refreshed = false; |
| int err = 0; |
| |
| if (!fuse_allow_current_process(fc)) |
| return -EACCES; |
| |
| /* |
| * If attributes are needed, refresh them before proceeding |
| */ |
| if (fc->default_permissions || |
| ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) { |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| |
| if (time_before64(fi->i_time, get_jiffies_64())) { |
| refreshed = true; |
| |
| err = fuse_perm_getattr(inode, mask); |
| if (err) |
| return err; |
| } |
| } |
| |
| if (fc->default_permissions) { |
| err = generic_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 && !refreshed) { |
| err = fuse_perm_getattr(inode, mask); |
| if (!err) |
| err = generic_permission(inode, mask); |
| } |
| |
| /* Note: the opposite of the above test does not |
| exist. So if permissions are revoked this won't be |
| noticed immediately, only after the attribute |
| timeout has expired */ |
| } else if (mask & (MAY_ACCESS | MAY_CHDIR)) { |
| err = fuse_access(inode, mask); |
| } else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) { |
| if (!(inode->i_mode & S_IXUGO)) { |
| if (refreshed) |
| return -EACCES; |
| |
| err = fuse_perm_getattr(inode, mask); |
| if (!err && !(inode->i_mode & S_IXUGO)) |
| return -EACCES; |
| } |
| } |
| return err; |
| } |
| |
| static int parse_dirfile(char *buf, size_t nbytes, struct file *file, |
| struct dir_context *ctx) |
| { |
| while (nbytes >= FUSE_NAME_OFFSET) { |
| struct fuse_dirent *dirent = (struct fuse_dirent *) buf; |
| size_t reclen = FUSE_DIRENT_SIZE(dirent); |
| if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX) |
| return -EIO; |
| if (reclen > nbytes) |
| break; |
| if (memchr(dirent->name, '/', dirent->namelen) != NULL) |
| return -EIO; |
| |
| if (!dir_emit(ctx, dirent->name, dirent->namelen, |
| dirent->ino, dirent->type)) |
| break; |
| |
| buf += reclen; |
| nbytes -= reclen; |
| ctx->pos = dirent->off; |
| } |
| |
| return 0; |
| } |
| |
| static int fuse_direntplus_link(struct file *file, |
| struct fuse_direntplus *direntplus, |
| u64 attr_version) |
| { |
| struct fuse_entry_out *o = &direntplus->entry_out; |
| struct fuse_dirent *dirent = &direntplus->dirent; |
| struct dentry *parent = file->f_path.dentry; |
| struct qstr name = QSTR_INIT(dirent->name, dirent->namelen); |
| struct dentry *dentry; |
| struct dentry *alias; |
| struct inode *dir = d_inode(parent); |
| struct fuse_conn *fc; |
| struct inode *inode; |
| DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); |
| |
| if (!o->nodeid) { |
| /* |
| * Unlike in the case of fuse_lookup, zero nodeid does not mean |
| * ENOENT. Instead, it only means the userspace filesystem did |
| * not want to return attributes/handle for this entry. |
| * |
| * So do nothing. |
| */ |
| return 0; |
| } |
| |
| if (name.name[0] == '.') { |
| /* |
| * We could potentially refresh the attributes of the directory |
| * and its parent? |
| */ |
| if (name.len == 1) |
| return 0; |
| if (name.name[1] == '.' && name.len == 2) |
| return 0; |
| } |
| |
| if (invalid_nodeid(o->nodeid)) |
| return -EIO; |
| if (!fuse_valid_type(o->attr.mode)) |
| return -EIO; |
| |
| fc = get_fuse_conn(dir); |
| |
| name.hash = full_name_hash(parent, name.name, name.len); |
| dentry = d_lookup(parent, &name); |
| if (!dentry) { |
| retry: |
| dentry = d_alloc_parallel(parent, &name, &wq); |
| if (IS_ERR(dentry)) |
| return PTR_ERR(dentry); |
| } |
| if (!d_in_lookup(dentry)) { |
| struct fuse_inode *fi; |
| inode = d_inode(dentry); |
| if (!inode || |
| get_node_id(inode) != o->nodeid || |
| ((o->attr.mode ^ inode->i_mode) & S_IFMT)) { |
| d_invalidate(dentry); |
| dput(dentry); |
| goto retry; |
| } |
| if (is_bad_inode(inode)) { |
| dput(dentry); |
| return -EIO; |
| } |
| |
| fi = get_fuse_inode(inode); |
| spin_lock(&fc->lock); |
| fi->nlookup++; |
| spin_unlock(&fc->lock); |
| |
| forget_all_cached_acls(inode); |
| fuse_change_attributes(inode, &o->attr, |
| entry_attr_timeout(o), |
| attr_version); |
| /* |
| * The other branch comes via fuse_iget() |
| * which bumps nlookup inside |
| */ |
| } else { |
| inode = fuse_iget(dir->i_sb, o->nodeid, o->generation, |
| &o->attr, entry_attr_timeout(o), |
| attr_version); |
| if (!inode) |
| inode = ERR_PTR(-ENOMEM); |
| |
| alias = d_splice_alias(inode, dentry); |
| d_lookup_done(dentry); |
| if (alias) { |
| dput(dentry); |
| dentry = alias; |
| } |
| if (IS_ERR(dentry)) |
| return PTR_ERR(dentry); |
| } |
| if (fc->readdirplus_auto) |
| set_bit(FUSE_I_INIT_RDPLUS, &get_fuse_inode(inode)->state); |
| fuse_change_entry_timeout(dentry, o); |
| |
| dput(dentry); |
| return 0; |
| } |
| |
| static int parse_dirplusfile(char *buf, size_t nbytes, struct file *file, |
| struct dir_context *ctx, u64 attr_version) |
| { |
| struct fuse_direntplus *direntplus; |
| struct fuse_dirent *dirent; |
| size_t reclen; |
| int over = 0; |
| int ret; |
| |
| while (nbytes >= FUSE_NAME_OFFSET_DIRENTPLUS) { |
| direntplus = (struct fuse_direntplus *) buf; |
| dirent = &direntplus->dirent; |
| reclen = FUSE_DIRENTPLUS_SIZE(direntplus); |
| |
| if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX) |
| return -EIO; |
| if (reclen > nbytes) |
| break; |
| if (memchr(dirent->name, '/', dirent->namelen) != NULL) |
| return -EIO; |
| |
| if (!over) { |
| /* We fill entries into dstbuf only as much as |
| it can hold. But we still continue iterating |
| over remaining entries to link them. If not, |
| we need to send a FORGET for each of those |
| which we did not link. |
| */ |
| over = !dir_emit(ctx, dirent->name, dirent->namelen, |
| dirent->ino, dirent->type); |
| if (!over) |
| ctx->pos = dirent->off; |
| } |
| |
| buf += reclen; |
| nbytes -= reclen; |
| |
| ret = fuse_direntplus_link(file, direntplus, attr_version); |
| if (ret) |
| fuse_force_forget(file, direntplus->entry_out.nodeid); |
| } |
| |
| return 0; |
| } |
| |
| static int fuse_readdir(struct file *file, struct dir_context *ctx) |
| { |
| int plus, err; |
| size_t nbytes; |
| struct page *page; |
| struct inode *inode = file_inode(file); |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_req *req; |
| u64 attr_version = 0; |
| |
| if (is_bad_inode(inode)) |
| return -EIO; |
| |
| req = fuse_get_req(fc, 1); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| page = alloc_page(GFP_KERNEL); |
| if (!page) { |
| fuse_put_request(fc, req); |
| return -ENOMEM; |
| } |
| |
| plus = fuse_use_readdirplus(inode, ctx); |
| req->out.argpages = 1; |
| req->num_pages = 1; |
| req->pages[0] = page; |
| req->page_descs[0].length = PAGE_SIZE; |
| if (plus) { |
| attr_version = fuse_get_attr_version(fc); |
| fuse_read_fill(req, file, ctx->pos, PAGE_SIZE, |
| FUSE_READDIRPLUS); |
| } else { |
| fuse_read_fill(req, file, ctx->pos, PAGE_SIZE, |
| FUSE_READDIR); |
| } |
| fuse_lock_inode(inode); |
| fuse_request_send(fc, req); |
| fuse_unlock_inode(inode); |
| nbytes = req->out.args[0].size; |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| if (!err) { |
| if (plus) { |
| err = parse_dirplusfile(page_address(page), nbytes, |
| file, ctx, |
| attr_version); |
| } else { |
| err = parse_dirfile(page_address(page), nbytes, file, |
| ctx); |
| } |
| } |
| |
| __free_page(page); |
| fuse_invalidate_atime(inode); |
| return err; |
| } |
| |
| static const char *fuse_get_link(struct dentry *dentry, |
| struct inode *inode, |
| struct delayed_call *done) |
| { |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| FUSE_ARGS(args); |
| char *link; |
| ssize_t ret; |
| |
| if (!dentry) |
| return ERR_PTR(-ECHILD); |
| |
| link = kmalloc(PAGE_SIZE, GFP_KERNEL); |
| if (!link) |
| return ERR_PTR(-ENOMEM); |
| |
| args.in.h.opcode = FUSE_READLINK; |
| args.in.h.nodeid = get_node_id(inode); |
| args.out.argvar = 1; |
| args.out.numargs = 1; |
| args.out.args[0].size = PAGE_SIZE - 1; |
| args.out.args[0].value = link; |
| ret = fuse_simple_request(fc, &args); |
| if (ret < 0) { |
| kfree(link); |
| link = ERR_PTR(ret); |
| } else { |
| link[ret] = '\0'; |
| set_delayed_call(done, kfree_link, link); |
| } |
| fuse_invalidate_atime(inode); |
| return link; |
| } |
| |
| static int fuse_dir_open(struct inode *inode, struct file *file) |
| { |
| return fuse_open_common(inode, file, true); |
| } |
| |
| static int fuse_dir_release(struct inode *inode, struct file *file) |
| { |
| fuse_release_common(file, FUSE_RELEASEDIR); |
| |
| return 0; |
| } |
| |
| static int fuse_dir_fsync(struct file *file, loff_t start, loff_t end, |
| int datasync) |
| { |
| return fuse_fsync_common(file, start, end, datasync, 1); |
| } |
| |
| static long fuse_dir_ioctl(struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host); |
| |
| /* FUSE_IOCTL_DIR only supported for API version >= 7.18 */ |
| if (fc->minor < 18) |
| return -ENOTTY; |
| |
| return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_DIR); |
| } |
| |
| static long fuse_dir_compat_ioctl(struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host); |
| |
| if (fc->minor < 18) |
| return -ENOTTY; |
| |
| return fuse_ioctl_common(file, cmd, arg, |
| FUSE_IOCTL_COMPAT | FUSE_IOCTL_DIR); |
| } |
| |
| static bool update_mtime(unsigned ivalid, bool trust_local_mtime) |
| { |
| /* Always update if mtime is explicitly set */ |
| if (ivalid & ATTR_MTIME_SET) |
| return true; |
| |
| /* Or if kernel i_mtime is the official one */ |
| if (trust_local_mtime) |
| return true; |
| |
| /* If it's an open(O_TRUNC) or an ftruncate(), don't update */ |
| if ((ivalid & ATTR_SIZE) && (ivalid & (ATTR_OPEN | ATTR_FILE))) |
| return false; |
| |
| /* In all other cases update */ |
| return true; |
| } |
| |
| static void iattr_to_fattr(struct fuse_conn *fc, struct iattr *iattr, |
| struct fuse_setattr_in *arg, bool trust_local_cmtime) |
| { |
| unsigned ivalid = iattr->ia_valid; |
| |
| if (ivalid & ATTR_MODE) |
| arg->valid |= FATTR_MODE, arg->mode = iattr->ia_mode; |
| if (ivalid & ATTR_UID) |
| arg->valid |= FATTR_UID, arg->uid = from_kuid(fc->user_ns, iattr->ia_uid); |
| if (ivalid & ATTR_GID) |
| arg->valid |= FATTR_GID, arg->gid = from_kgid(fc->user_ns, iattr->ia_gid); |
| if (ivalid & ATTR_SIZE) |
| arg->valid |= FATTR_SIZE, arg->size = iattr->ia_size; |
| if (ivalid & ATTR_ATIME) { |
| arg->valid |= FATTR_ATIME; |
| arg->atime = iattr->ia_atime.tv_sec; |
| arg->atimensec = iattr->ia_atime.tv_nsec; |
| if (!(ivalid & ATTR_ATIME_SET)) |
| arg->valid |= FATTR_ATIME_NOW; |
| } |
| if ((ivalid & ATTR_MTIME) && update_mtime(ivalid, trust_local_cmtime)) { |
| arg->valid |= FATTR_MTIME; |
| arg->mtime = iattr->ia_mtime.tv_sec; |
| arg->mtimensec = iattr->ia_mtime.tv_nsec; |
| if (!(ivalid & ATTR_MTIME_SET) && !trust_local_cmtime) |
| arg->valid |= FATTR_MTIME_NOW; |
| } |
| if ((ivalid & ATTR_CTIME) && trust_local_cmtime) { |
| arg->valid |= FATTR_CTIME; |
| arg->ctime = iattr->ia_ctime.tv_sec; |
| arg->ctimensec = iattr->ia_ctime.tv_nsec; |
| } |
| } |
| |
| /* |
| * Prevent concurrent writepages on inode |
| * |
| * This is done by adding a negative bias to the inode write counter |
| * and waiting for all pending writes to finish. |
| */ |
| void fuse_set_nowrite(struct inode *inode) |
| { |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| |
| BUG_ON(!inode_is_locked(inode)); |
| |
| spin_lock(&fc->lock); |
| BUG_ON(fi->writectr < 0); |
| fi->writectr += FUSE_NOWRITE; |
| spin_unlock(&fc->lock); |
| wait_event(fi->page_waitq, fi->writectr == FUSE_NOWRITE); |
| } |
| |
| /* |
| * Allow writepages on inode |
| * |
| * Remove the bias from the writecounter and send any queued |
| * writepages. |
| */ |
| static void __fuse_release_nowrite(struct inode *inode) |
| { |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| |
| BUG_ON(fi->writectr != FUSE_NOWRITE); |
| fi->writectr = 0; |
| fuse_flush_writepages(inode); |
| } |
| |
| void fuse_release_nowrite(struct inode *inode) |
| { |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| |
| spin_lock(&fc->lock); |
| __fuse_release_nowrite(inode); |
| spin_unlock(&fc->lock); |
| } |
| |
| static void fuse_setattr_fill(struct fuse_conn *fc, struct fuse_args *args, |
| struct inode *inode, |
| struct fuse_setattr_in *inarg_p, |
| struct fuse_attr_out *outarg_p) |
| { |
| args->in.h.opcode = FUSE_SETATTR; |
| args->in.h.nodeid = get_node_id(inode); |
| args->in.numargs = 1; |
| args->in.args[0].size = sizeof(*inarg_p); |
| args->in.args[0].value = inarg_p; |
| args->out.numargs = 1; |
| args->out.args[0].size = sizeof(*outarg_p); |
| args->out.args[0].value = outarg_p; |
| } |
| |
| /* |
| * Flush inode->i_mtime to the server |
| */ |
| int fuse_flush_times(struct inode *inode, struct fuse_file *ff) |
| { |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| FUSE_ARGS(args); |
| struct fuse_setattr_in inarg; |
| struct fuse_attr_out outarg; |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| memset(&outarg, 0, sizeof(outarg)); |
| |
| inarg.valid = FATTR_MTIME; |
| inarg.mtime = inode->i_mtime.tv_sec; |
| inarg.mtimensec = inode->i_mtime.tv_nsec; |
| if (fc->minor >= 23) { |
| inarg.valid |= FATTR_CTIME; |
| inarg.ctime = inode->i_ctime.tv_sec; |
| inarg.ctimensec = inode->i_ctime.tv_nsec; |
| } |
| if (ff) { |
| inarg.valid |= FATTR_FH; |
| inarg.fh = ff->fh; |
| } |
| fuse_setattr_fill(fc, &args, inode, &inarg, &outarg); |
| |
| return fuse_simple_request(fc, &args); |
| } |
| |
| /* |
| * Set attributes, and at the same time refresh them. |
| * |
| * Truncation is slightly complicated, because the 'truncate' request |
| * may fail, in which case we don't want to touch the mapping. |
| * vmtruncate() doesn't allow for this case, so do the rlimit checking |
| * and the actual truncation by hand. |
| */ |
| int fuse_do_setattr(struct dentry *dentry, struct iattr *attr, |
| struct file *file) |
| { |
| struct inode *inode = d_inode(dentry); |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| FUSE_ARGS(args); |
| struct fuse_setattr_in inarg; |
| struct fuse_attr_out outarg; |
| bool is_truncate = false; |
| bool is_wb = fc->writeback_cache; |
| loff_t oldsize; |
| int err; |
| bool trust_local_cmtime = is_wb && S_ISREG(inode->i_mode); |
| |
| if (!fc->default_permissions) |
| attr->ia_valid |= ATTR_FORCE; |
| |
| err = setattr_prepare(dentry, attr); |
| if (err) |
| return err; |
| |
| if (attr->ia_valid & ATTR_OPEN) { |
| /* This is coming from open(..., ... | O_TRUNC); */ |
| WARN_ON(!(attr->ia_valid & ATTR_SIZE)); |
| WARN_ON(attr->ia_size != 0); |
| if (fc->atomic_o_trunc) { |
| /* |
| * No need to send request to userspace, since actual |
| * truncation has already been done by OPEN. But still |
| * need to truncate page cache. |
| */ |
| i_size_write(inode, 0); |
| truncate_pagecache(inode, 0); |
| return 0; |
| } |
| file = NULL; |
| } |
| |
| if (attr->ia_valid & ATTR_SIZE) |
| is_truncate = true; |
| |
| if (is_truncate) { |
| fuse_set_nowrite(inode); |
| set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); |
| if (trust_local_cmtime && attr->ia_size != inode->i_size) |
| attr->ia_valid |= ATTR_MTIME | ATTR_CTIME; |
| } |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| memset(&outarg, 0, sizeof(outarg)); |
| iattr_to_fattr(fc, attr, &inarg, trust_local_cmtime); |
| if (file) { |
| struct fuse_file *ff = file->private_data; |
| inarg.valid |= FATTR_FH; |
| inarg.fh = ff->fh; |
| } |
| if (attr->ia_valid & ATTR_SIZE) { |
| /* For mandatory locking in truncate */ |
| inarg.valid |= FATTR_LOCKOWNER; |
| inarg.lock_owner = fuse_lock_owner_id(fc, current->files); |
| } |
| fuse_setattr_fill(fc, &args, inode, &inarg, &outarg); |
| err = fuse_simple_request(fc, &args); |
| if (err) { |
| if (err == -EINTR) |
| fuse_invalidate_attr(inode); |
| goto error; |
| } |
| |
| if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) { |
| make_bad_inode(inode); |
| err = -EIO; |
| goto error; |
| } |
| |
| spin_lock(&fc->lock); |
| /* the kernel maintains i_mtime locally */ |
| if (trust_local_cmtime) { |
| if (attr->ia_valid & ATTR_MTIME) |
| inode->i_mtime = attr->ia_mtime; |
| if (attr->ia_valid & ATTR_CTIME) |
| inode->i_ctime = attr->ia_ctime; |
| /* FIXME: clear I_DIRTY_SYNC? */ |
| } |
| |
| fuse_change_attributes_common(inode, &outarg.attr, |
| attr_timeout(&outarg)); |
| oldsize = inode->i_size; |
| /* see the comment in fuse_change_attributes() */ |
| if (!is_wb || is_truncate || !S_ISREG(inode->i_mode)) |
| i_size_write(inode, outarg.attr.size); |
| |
| if (is_truncate) { |
| /* NOTE: this may release/reacquire fc->lock */ |
| __fuse_release_nowrite(inode); |
| } |
| spin_unlock(&fc->lock); |
| |
| /* |
| * Only call invalidate_inode_pages2() after removing |
| * FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock. |
| */ |
| if ((is_truncate || !is_wb) && |
| S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) { |
| truncate_pagecache(inode, outarg.attr.size); |
| invalidate_inode_pages2(inode->i_mapping); |
| } |
| |
| clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); |
| return 0; |
| |
| error: |
| if (is_truncate) |
| fuse_release_nowrite(inode); |
| |
| clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); |
| return err; |
| } |
| |
| static int fuse_setattr(struct dentry *entry, struct iattr *attr) |
| { |
| struct inode *inode = d_inode(entry); |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct file *file = (attr->ia_valid & ATTR_FILE) ? attr->ia_file : NULL; |
| int ret; |
| |
| if (!fuse_allow_current_process(get_fuse_conn(inode))) |
| return -EACCES; |
| |
| if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID)) { |
| attr->ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | |
| ATTR_MODE); |
| |
| /* |
| * The only sane way to reliably kill suid/sgid is to do it in |
| * the userspace filesystem |
| * |
| * This should be done on write(), truncate() and chown(). |
| */ |
| if (!fc->handle_killpriv) { |
| /* |
| * ia_mode calculation may have used stale i_mode. |
| * Refresh and recalculate. |
| */ |
| ret = fuse_do_getattr(inode, NULL, file); |
| if (ret) |
| return ret; |
| |
| attr->ia_mode = inode->i_mode; |
| if (inode->i_mode & S_ISUID) { |
| attr->ia_valid |= ATTR_MODE; |
| attr->ia_mode &= ~S_ISUID; |
| } |
| if ((inode->i_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { |
| attr->ia_valid |= ATTR_MODE; |
| attr->ia_mode &= ~S_ISGID; |
| } |
| } |
| } |
| if (!attr->ia_valid) |
| return 0; |
| |
| ret = fuse_do_setattr(entry, attr, file); |
| if (!ret) { |
| /* |
| * If filesystem supports acls it may have updated acl xattrs in |
| * the filesystem, so forget cached acls for the inode. |
| */ |
| if (fc->posix_acl) |
| forget_all_cached_acls(inode); |
| |
| /* Directory mode changed, may need to revalidate access */ |
| if (d_is_dir(entry) && (attr->ia_valid & ATTR_MODE)) |
| fuse_invalidate_entry_cache(entry); |
| } |
| return ret; |
| } |
| |
| static int fuse_getattr(const struct path *path, struct kstat *stat, |
| u32 request_mask, unsigned int flags) |
| { |
| struct inode *inode = d_inode(path->dentry); |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| |
| if (!fuse_allow_current_process(fc)) |
| return -EACCES; |
| |
| return fuse_update_get_attr(inode, NULL, stat, flags); |
| } |
| |
| static const struct inode_operations fuse_dir_inode_operations = { |
| .lookup = fuse_lookup, |
| .mkdir = fuse_mkdir, |
| .symlink = fuse_symlink, |
| .unlink = fuse_unlink, |
| .rmdir = fuse_rmdir, |
| .rename = fuse_rename2, |
| .link = fuse_link, |
| .setattr = fuse_setattr, |
| .create = fuse_create, |
| .atomic_open = fuse_atomic_open, |
| .mknod = fuse_mknod, |
| .permission = fuse_permission, |
| .getattr = fuse_getattr, |
| .listxattr = fuse_listxattr, |
| .get_acl = fuse_get_acl, |
| .set_acl = fuse_set_acl, |
| }; |
| |
| static const struct file_operations fuse_dir_operations = { |
| .llseek = generic_file_llseek, |
| .read = generic_read_dir, |
| .iterate_shared = fuse_readdir, |
| .open = fuse_dir_open, |
| .release = fuse_dir_release, |
| .fsync = fuse_dir_fsync, |
| .unlocked_ioctl = fuse_dir_ioctl, |
| .compat_ioctl = fuse_dir_compat_ioctl, |
| }; |
| |
| static const struct inode_operations fuse_common_inode_operations = { |
| .setattr = fuse_setattr, |
| .permission = fuse_permission, |
| .getattr = fuse_getattr, |
| .listxattr = fuse_listxattr, |
| .get_acl = fuse_get_acl, |
| .set_acl = fuse_set_acl, |
| }; |
| |
| static const struct inode_operations fuse_symlink_inode_operations = { |
| .setattr = fuse_setattr, |
| .get_link = fuse_get_link, |
| .getattr = fuse_getattr, |
| .listxattr = fuse_listxattr, |
| }; |
| |
| 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; |
| } |