| /* |
| 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> |
| |
| #if BITS_PER_LONG >= 64 |
| static inline void fuse_dentry_settime(struct dentry *entry, u64 time) |
| { |
| entry->d_time = time; |
| } |
| |
| static inline u64 fuse_dentry_time(struct dentry *entry) |
| { |
| return entry->d_time; |
| } |
| #else |
| /* |
| * On 32 bit archs store the high 32 bits of time in d_fsdata |
| */ |
| static void fuse_dentry_settime(struct dentry *entry, u64 time) |
| { |
| entry->d_time = time; |
| entry->d_fsdata = (void *) (unsigned long) (time >> 32); |
| } |
| |
| static u64 fuse_dentry_time(struct dentry *entry) |
| { |
| return (u64) entry->d_time + |
| ((u64) (unsigned long) entry->d_fsdata << 32); |
| } |
| #endif |
| |
| /* |
| * FUSE caches dentries and attributes with separate timeout. The |
| * time in jiffies until the dentry/attributes are valid is stored in |
| * dentry->d_time and fuse_inode->i_time respectively. |
| */ |
| |
| /* |
| * Calculate the time in jiffies until a dentry/attributes are valid |
| */ |
| static u64 time_to_jiffies(unsigned long sec, unsigned long nsec) |
| { |
| if (sec || nsec) { |
| struct timespec ts = {sec, nsec}; |
| return get_jiffies_64() + timespec_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; |
| } |
| |
| /* |
| * 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_req *req, |
| u64 nodeid, struct qstr *name, |
| struct fuse_entry_out *outarg) |
| { |
| memset(outarg, 0, sizeof(struct fuse_entry_out)); |
| req->in.h.opcode = FUSE_LOOKUP; |
| req->in.h.nodeid = nodeid; |
| req->in.numargs = 1; |
| req->in.args[0].size = name->len + 1; |
| req->in.args[0].value = name->name; |
| req->out.numargs = 1; |
| if (fc->minor < 9) |
| req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE; |
| else |
| req->out.args[0].size = sizeof(struct fuse_entry_out); |
| req->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; |
| |
| inode = ACCESS_ONCE(entry->d_inode); |
| if (inode && is_bad_inode(inode)) |
| return 0; |
| else if (fuse_dentry_time(entry) < get_jiffies_64()) { |
| int err; |
| struct fuse_entry_out outarg; |
| struct fuse_conn *fc; |
| struct fuse_req *req; |
| struct fuse_forget_link *forget; |
| struct dentry *parent; |
| u64 attr_version; |
| |
| /* For negative dentries, always do a fresh lookup */ |
| if (!inode) |
| return 0; |
| |
| if (flags & LOOKUP_RCU) |
| return -ECHILD; |
| |
| fc = get_fuse_conn(inode); |
| req = fuse_get_req(fc); |
| if (IS_ERR(req)) |
| return 0; |
| |
| forget = fuse_alloc_forget(); |
| if (!forget) { |
| fuse_put_request(fc, req); |
| return 0; |
| } |
| |
| attr_version = fuse_get_attr_version(fc); |
| |
| parent = dget_parent(entry); |
| fuse_lookup_init(fc, req, get_node_id(parent->d_inode), |
| &entry->d_name, &outarg); |
| fuse_request_send(fc, req); |
| dput(parent); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| /* Zero nodeid is same as -ENOENT */ |
| if (!err && !outarg.nodeid) |
| err = -ENOENT; |
| if (!err) { |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| if (outarg.nodeid != get_node_id(inode)) { |
| fuse_queue_forget(fc, forget, outarg.nodeid, 1); |
| return 0; |
| } |
| spin_lock(&fc->lock); |
| fi->nlookup++; |
| spin_unlock(&fc->lock); |
| } |
| kfree(forget); |
| if (err || (outarg.attr.mode ^ inode->i_mode) & S_IFMT) |
| return 0; |
| |
| fuse_change_attributes(inode, &outarg.attr, |
| entry_attr_timeout(&outarg), |
| attr_version); |
| fuse_change_entry_timeout(entry, &outarg); |
| } |
| return 1; |
| } |
| |
| /* |
| * Get the canonical path. Since we must translate to a path, this must be done |
| * in the context of the userspace daemon, however, the userspace daemon cannot |
| * look up paths on its own. Instead, we handle the lookup as a special case |
| * inside of the write request. |
| */ |
| static void fuse_dentry_canonical_path(const struct path *path, struct path *canonical_path) { |
| struct inode *inode = path->dentry->d_inode; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_req *req; |
| int err; |
| char *path_name; |
| |
| req = fuse_get_req(fc); |
| err = PTR_ERR(req); |
| if (IS_ERR(req)) |
| goto default_path; |
| |
| path_name = (char*)__get_free_page(GFP_KERNEL); |
| if (!path_name) { |
| fuse_put_request(fc, req); |
| goto default_path; |
| } |
| |
| req->in.h.opcode = FUSE_CANONICAL_PATH; |
| req->in.h.nodeid = get_node_id(inode); |
| req->in.numargs = 0; |
| req->out.numargs = 1; |
| req->out.args[0].size = PATH_MAX; |
| req->out.args[0].value = path_name; |
| req->canonical_path = canonical_path; |
| req->out.argvar = 1; |
| fuse_request_send(fc, req); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| free_page((unsigned long)path_name); |
| if (!err) |
| return; |
| default_path: |
| canonical_path->dentry = path->dentry; |
| canonical_path->mnt = path->mnt; |
| path_get(canonical_path); |
| } |
| |
| static int invalid_nodeid(u64 nodeid) |
| { |
| return !nodeid || nodeid == FUSE_ROOT_ID; |
| } |
| |
| const struct dentry_operations fuse_dentry_operations = { |
| .d_revalidate = fuse_dentry_revalidate, |
| .d_canonical_path = fuse_dentry_canonical_path, |
| }; |
| |
| 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); |
| } |
| |
| /* |
| * Add a directory inode to a dentry, ensuring that no other dentry |
| * refers to this inode. Called with fc->inst_mutex. |
| */ |
| static struct dentry *fuse_d_add_directory(struct dentry *entry, |
| struct inode *inode) |
| { |
| struct dentry *alias = d_find_alias(inode); |
| if (alias && !(alias->d_flags & DCACHE_DISCONNECTED)) { |
| /* This tries to shrink the subtree below alias */ |
| fuse_invalidate_entry(alias); |
| dput(alias); |
| if (!list_empty(&inode->i_dentry)) |
| return ERR_PTR(-EBUSY); |
| } else { |
| dput(alias); |
| } |
| return d_splice_alias(inode, entry); |
| } |
| |
| int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name, |
| struct fuse_entry_out *outarg, struct inode **inode) |
| { |
| struct fuse_conn *fc = get_fuse_conn_super(sb); |
| struct fuse_req *req; |
| struct fuse_forget_link *forget; |
| u64 attr_version; |
| int err; |
| |
| *inode = NULL; |
| err = -ENAMETOOLONG; |
| if (name->len > FUSE_NAME_MAX) |
| goto out; |
| |
| req = fuse_get_req(fc); |
| err = PTR_ERR(req); |
| if (IS_ERR(req)) |
| goto out; |
| |
| forget = fuse_alloc_forget(); |
| err = -ENOMEM; |
| if (!forget) { |
| fuse_put_request(fc, req); |
| goto out; |
| } |
| |
| attr_version = fuse_get_attr_version(fc); |
| |
| fuse_lookup_init(fc, req, nodeid, name, outarg); |
| fuse_request_send(fc, req); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| /* 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; |
| struct fuse_conn *fc = get_fuse_conn(dir); |
| bool outarg_valid = true; |
| |
| err = fuse_lookup_name(dir->i_sb, get_node_id(dir), &entry->d_name, |
| &outarg, &inode); |
| 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; |
| |
| if (inode && S_ISDIR(inode->i_mode)) { |
| mutex_lock(&fc->inst_mutex); |
| newent = fuse_d_add_directory(entry, inode); |
| mutex_unlock(&fc->inst_mutex); |
| err = PTR_ERR(newent); |
| if (IS_ERR(newent)) |
| goto out_iput; |
| } else { |
| newent = d_splice_alias(inode, entry); |
| } |
| |
| entry = newent ? newent : entry; |
| if (outarg_valid) |
| fuse_change_entry_timeout(entry, &outarg); |
| else |
| fuse_invalidate_entry_cache(entry); |
| |
| 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); |
| struct fuse_req *req; |
| struct fuse_forget_link *forget; |
| struct fuse_create_in inarg; |
| struct fuse_open_out outopen; |
| struct fuse_entry_out outentry; |
| struct fuse_file *ff; |
| |
| forget = fuse_alloc_forget(); |
| err = -ENOMEM; |
| if (!forget) |
| goto out_err; |
| |
| req = fuse_get_req(fc); |
| err = PTR_ERR(req); |
| if (IS_ERR(req)) |
| goto out_put_forget_req; |
| |
| err = -ENOMEM; |
| ff = fuse_file_alloc(fc); |
| if (!ff) |
| goto out_put_request; |
| |
| 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(); |
| req->in.h.opcode = FUSE_CREATE; |
| req->in.h.nodeid = get_node_id(dir); |
| req->in.numargs = 2; |
| req->in.args[0].size = fc->minor < 12 ? sizeof(struct fuse_open_in) : |
| 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 = 2; |
| if (fc->minor < 9) |
| req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE; |
| else |
| req->out.args[0].size = sizeof(outentry); |
| req->out.args[0].value = &outentry; |
| req->out.args[1].size = sizeof(outopen); |
| req->out.args[1].value = &outopen; |
| fuse_request_send(fc, req); |
| err = req->out.h.error; |
| if (err) |
| goto out_free_ff; |
| |
| if (req->private_lower_rw_file != NULL) |
| ff->rw_lower_file = req->private_lower_rw_file; |
| |
| err = -EIO; |
| if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid)) |
| goto out_free_ff; |
| |
| fuse_put_request(fc, req); |
| 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, opened); |
| if (err) { |
| fuse_sync_release(ff, flags); |
| } else { |
| file->private_data = fuse_file_get(ff); |
| fuse_finish_open(inode, file); |
| } |
| return err; |
| |
| out_free_ff: |
| fuse_file_free(ff); |
| out_put_request: |
| fuse_put_request(fc, req); |
| 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_unhashed(entry)) { |
| res = fuse_lookup(dir, entry, 0); |
| if (IS_ERR(res)) |
| return PTR_ERR(res); |
| |
| if (res) |
| entry = res; |
| } |
| |
| if (!(flags & O_CREAT) || entry->d_inode) |
| goto no_open; |
| |
| /* Only creates */ |
| *opened |= FILE_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_req *req, |
| 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) { |
| fuse_put_request(fc, req); |
| return -ENOMEM; |
| } |
| |
| memset(&outarg, 0, sizeof(outarg)); |
| req->in.h.nodeid = get_node_id(dir); |
| req->out.numargs = 1; |
| if (fc->minor < 9) |
| req->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE; |
| else |
| req->out.args[0].size = sizeof(outarg); |
| req->out.args[0].value = &outarg; |
| fuse_request_send(fc, req); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| 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); |
| |
| if (S_ISDIR(inode->i_mode)) { |
| struct dentry *alias; |
| mutex_lock(&fc->inst_mutex); |
| alias = d_find_alias(inode); |
| if (alias) { |
| /* New directory must have moved since mkdir */ |
| mutex_unlock(&fc->inst_mutex); |
| dput(alias); |
| iput(inode); |
| return -EBUSY; |
| } |
| d_instantiate(entry, inode); |
| mutex_unlock(&fc->inst_mutex); |
| } else |
| d_instantiate(entry, inode); |
| |
| 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); |
| struct fuse_req *req = fuse_get_req(fc); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| 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(); |
| req->in.h.opcode = FUSE_MKNOD; |
| req->in.numargs = 2; |
| req->in.args[0].size = fc->minor < 12 ? FUSE_COMPAT_MKNOD_IN_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; |
| return create_new_entry(fc, req, dir, entry, mode); |
| } |
| |
| static int fuse_create(struct inode *dir, struct dentry *entry, umode_t mode, |
| struct nameidata *nd) |
| { |
| 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); |
| struct fuse_req *req = fuse_get_req(fc); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| if (!fc->dont_mask) |
| mode &= ~current_umask(); |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.mode = mode; |
| inarg.umask = current_umask(); |
| req->in.h.opcode = FUSE_MKDIR; |
| 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; |
| return create_new_entry(fc, req, 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; |
| struct fuse_req *req = fuse_get_req(fc); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| req->in.h.opcode = FUSE_SYMLINK; |
| 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; |
| return create_new_entry(fc, req, dir, entry, S_IFLNK); |
| } |
| |
| static int fuse_unlink(struct inode *dir, struct dentry *entry) |
| { |
| int err; |
| struct fuse_conn *fc = get_fuse_conn(dir); |
| struct fuse_req *req = fuse_get_req(fc); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| req->in.h.opcode = FUSE_UNLINK; |
| req->in.h.nodeid = get_node_id(dir); |
| req->in.numargs = 1; |
| req->in.args[0].size = entry->d_name.len + 1; |
| req->in.args[0].value = entry->d_name.name; |
| fuse_request_send(fc, req); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| if (!err) { |
| struct inode *inode = entry->d_inode; |
| 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); |
| } 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); |
| struct fuse_req *req = fuse_get_req(fc); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| req->in.h.opcode = FUSE_RMDIR; |
| req->in.h.nodeid = get_node_id(dir); |
| req->in.numargs = 1; |
| req->in.args[0].size = entry->d_name.len + 1; |
| req->in.args[0].value = entry->d_name.name; |
| fuse_request_send(fc, req); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| if (!err) { |
| clear_nlink(entry->d_inode); |
| fuse_invalidate_attr(dir); |
| fuse_invalidate_entry_cache(entry); |
| } else if (err == -EINTR) |
| fuse_invalidate_entry(entry); |
| return err; |
| } |
| |
| static int fuse_rename(struct inode *olddir, struct dentry *oldent, |
| struct inode *newdir, struct dentry *newent) |
| { |
| int err; |
| struct fuse_rename_in inarg; |
| struct fuse_conn *fc = get_fuse_conn(olddir); |
| struct fuse_req *req = fuse_get_req(fc); |
| |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.newdir = get_node_id(newdir); |
| req->in.h.opcode = FUSE_RENAME; |
| req->in.h.nodeid = get_node_id(olddir); |
| 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; |
| fuse_request_send(fc, req); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| if (!err) { |
| /* ctime changes */ |
| fuse_invalidate_attr(oldent->d_inode); |
| |
| fuse_invalidate_attr(olddir); |
| if (olddir != newdir) |
| fuse_invalidate_attr(newdir); |
| |
| /* newent will end up negative */ |
| if (newent->d_inode) { |
| fuse_invalidate_attr(newent->d_inode); |
| fuse_invalidate_entry_cache(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 (newent->d_inode) |
| fuse_invalidate_entry(newent); |
| } |
| |
| 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 = entry->d_inode; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_req *req = fuse_get_req(fc); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.oldnodeid = get_node_id(inode); |
| req->in.h.opcode = FUSE_LINK; |
| 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; |
| err = create_new_entry(fc, req, 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); |
| } else if (err == -EINTR) { |
| fuse_invalidate_attr(inode); |
| } |
| return err; |
| } |
| |
| static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr, |
| struct kstat *stat) |
| { |
| 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 = attr->uid; |
| stat->gid = 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; |
| stat->blksize = (1 << inode->i_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); |
| struct fuse_req *req; |
| u64 attr_version; |
| |
| req = fuse_get_req(fc); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| 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; |
| } |
| req->in.h.opcode = FUSE_GETATTR; |
| req->in.h.nodeid = get_node_id(inode); |
| req->in.numargs = 1; |
| req->in.args[0].size = sizeof(inarg); |
| req->in.args[0].value = &inarg; |
| req->out.numargs = 1; |
| if (fc->minor < 9) |
| req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE; |
| else |
| req->out.args[0].size = sizeof(outarg); |
| req->out.args[0].value = &outarg; |
| fuse_request_send(fc, req); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| 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; |
| } |
| |
| int fuse_update_attributes(struct inode *inode, struct kstat *stat, |
| struct file *file, bool *refreshed) |
| { |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| int err; |
| bool r; |
| |
| if (fi->i_time < get_jiffies_64()) { |
| r = true; |
| err = fuse_do_getattr(inode, stat, file); |
| } else { |
| r = false; |
| err = 0; |
| if (stat) { |
| generic_fillattr(inode, stat); |
| stat->mode = fi->orig_i_mode; |
| stat->ino = fi->orig_ino; |
| } |
| } |
| |
| if (refreshed != NULL) |
| *refreshed = r; |
| |
| return err; |
| } |
| |
| 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; |
| |
| mutex_lock(&parent->i_mutex); |
| if (!S_ISDIR(parent->i_mode)) |
| goto unlock; |
| |
| err = -ENOENT; |
| dir = d_find_alias(parent); |
| if (!dir) |
| goto unlock; |
| |
| entry = d_lookup(dir, name); |
| dput(dir); |
| if (!entry) |
| goto unlock; |
| |
| fuse_invalidate_attr(parent); |
| fuse_invalidate_entry(entry); |
| |
| if (child_nodeid != 0 && entry->d_inode) { |
| mutex_lock(&entry->d_inode->i_mutex); |
| if (get_node_id(entry->d_inode) != child_nodeid) { |
| err = -ENOENT; |
| goto badentry; |
| } |
| if (d_mountpoint(entry)) { |
| err = -EBUSY; |
| goto badentry; |
| } |
| if (S_ISDIR(entry->d_inode->i_mode)) { |
| shrink_dcache_parent(entry); |
| if (!simple_empty(entry)) { |
| err = -ENOTEMPTY; |
| goto badentry; |
| } |
| entry->d_inode->i_flags |= S_DEAD; |
| } |
| dont_mount(entry); |
| clear_nlink(entry->d_inode); |
| err = 0; |
| badentry: |
| mutex_unlock(&entry->d_inode->i_mutex); |
| if (!err) |
| d_delete(entry); |
| } else { |
| err = 0; |
| } |
| dput(entry); |
| |
| unlock: |
| mutex_unlock(&parent->i_mutex); |
| iput(parent); |
| return err; |
| } |
| |
| /* |
| * Calling into a user-controlled filesystem gives the filesystem |
| * daemon ptrace-like capabilities over the requester 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_task(struct fuse_conn *fc, struct task_struct *task) |
| { |
| const struct cred *cred; |
| int ret; |
| |
| if (fc->flags & FUSE_ALLOW_OTHER) |
| return 1; |
| |
| rcu_read_lock(); |
| ret = 0; |
| cred = __task_cred(task); |
| if (cred->euid == fc->user_id && |
| cred->suid == fc->user_id && |
| cred->uid == fc->user_id && |
| cred->egid == fc->group_id && |
| cred->sgid == fc->group_id && |
| cred->gid == fc->group_id) |
| ret = 1; |
| rcu_read_unlock(); |
| |
| return ret; |
| } |
| |
| static int fuse_access(struct inode *inode, int mask) |
| { |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_req *req; |
| struct fuse_access_in inarg; |
| int err; |
| |
| if (fc->no_access) |
| return 0; |
| |
| req = fuse_get_req(fc); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.mask = mask & (MAY_READ | MAY_WRITE | MAY_EXEC); |
| req->in.h.opcode = FUSE_ACCESS; |
| req->in.h.nodeid = get_node_id(inode); |
| req->in.numargs = 1; |
| req->in.args[0].size = sizeof(inarg); |
| req->in.args[0].value = &inarg; |
| fuse_request_send(fc, req); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| 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; |
| |
| 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_task(fc, current)) |
| return -EACCES; |
| |
| /* |
| * If attributes are needed, refresh them before proceeding |
| */ |
| if ((fc->flags & FUSE_DEFAULT_PERMISSIONS) || |
| ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) { |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| |
| if (fi->i_time < get_jiffies_64()) { |
| refreshed = true; |
| |
| err = fuse_perm_getattr(inode, mask); |
| if (err) |
| return err; |
| } |
| } |
| |
| if (fc->flags & FUSE_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)) { |
| if (mask & MAY_NOT_BLOCK) |
| return -ECHILD; |
| |
| 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, |
| 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; |
| if (memchr(dirent->name, '/', dirent->namelen) != NULL) |
| return -EIO; |
| |
| 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_readdir(struct file *file, void *dstbuf, filldir_t filldir) |
| { |
| int err; |
| size_t nbytes; |
| struct page *page; |
| struct inode *inode = file->f_path.dentry->d_inode; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_req *req; |
| |
| if (is_bad_inode(inode)) |
| return -EIO; |
| |
| req = fuse_get_req(fc); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| page = alloc_page(GFP_KERNEL); |
| if (!page) { |
| fuse_put_request(fc, req); |
| return -ENOMEM; |
| } |
| req->out.argpages = 1; |
| req->num_pages = 1; |
| req->pages[0] = page; |
| fuse_read_fill(req, file, file->f_pos, PAGE_SIZE, FUSE_READDIR); |
| fuse_request_send(fc, req); |
| nbytes = req->out.args[0].size; |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| if (!err) |
| err = parse_dirfile(page_address(page), nbytes, file, dstbuf, |
| filldir); |
| |
| __free_page(page); |
| fuse_invalidate_attr(inode); /* atime changed */ |
| return err; |
| } |
| |
| 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_req(fc); |
| char *link; |
| |
| if (IS_ERR(req)) |
| return ERR_CAST(req); |
| |
| 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->out.argvar = 1; |
| req->out.numargs = 1; |
| req->out.args[0].size = PAGE_SIZE - 1; |
| req->out.args[0].value = link; |
| fuse_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); |
| fuse_invalidate_attr(inode); /* atime changed */ |
| 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) |
| { |
| 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) |
| { |
| /* Always update if mtime is explicitly set */ |
| if (ivalid & ATTR_MTIME_SET) |
| 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 iattr *iattr, struct fuse_setattr_in *arg) |
| { |
| 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 = iattr->ia_uid; |
| if (ivalid & ATTR_GID) |
| arg->valid |= FATTR_GID, arg->gid = 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)) { |
| arg->valid |= FATTR_MTIME; |
| arg->mtime = iattr->ia_mtime.tv_sec; |
| arg->mtimensec = iattr->ia_mtime.tv_nsec; |
| if (!(ivalid & ATTR_MTIME_SET)) |
| arg->valid |= FATTR_MTIME_NOW; |
| } |
| } |
| |
| /* |
| * 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(!mutex_is_locked(&inode->i_mutex)); |
| |
| 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); |
| } |
| |
| /* |
| * 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. |
| */ |
| static int fuse_do_setattr(struct dentry *entry, struct iattr *attr, |
| struct file *file) |
| { |
| struct inode *inode = entry->d_inode; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| struct fuse_req *req; |
| struct fuse_setattr_in inarg; |
| struct fuse_attr_out outarg; |
| bool is_truncate = false; |
| loff_t oldsize; |
| int err; |
| |
| if (!fuse_allow_task(fc, current)) |
| return -EACCES; |
| |
| if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS)) |
| attr->ia_valid |= ATTR_FORCE; |
| |
| err = inode_change_ok(inode, attr); |
| if (err) |
| return err; |
| |
| if (attr->ia_valid & ATTR_OPEN) { |
| if (fc->atomic_o_trunc) |
| return 0; |
| file = NULL; |
| } |
| |
| if (attr->ia_valid & ATTR_SIZE) |
| is_truncate = true; |
| |
| req = fuse_get_req(fc); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| if (is_truncate) { |
| fuse_set_nowrite(inode); |
| set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); |
| } |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| memset(&outarg, 0, sizeof(outarg)); |
| iattr_to_fattr(attr, &inarg); |
| 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); |
| } |
| req->in.h.opcode = FUSE_SETATTR; |
| req->in.h.nodeid = get_node_id(inode); |
| req->in.numargs = 1; |
| req->in.args[0].size = sizeof(inarg); |
| req->in.args[0].value = &inarg; |
| req->out.numargs = 1; |
| if (fc->minor < 9) |
| req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE; |
| else |
| req->out.args[0].size = sizeof(outarg); |
| req->out.args[0].value = &outarg; |
| fuse_request_send(fc, req); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| 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); |
| fuse_change_attributes_common(inode, &outarg.attr, |
| attr_timeout(&outarg)); |
| oldsize = inode->i_size; |
| 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 (S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) { |
| truncate_pagecache(inode, oldsize, 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) |
| { |
| if (attr->ia_valid & ATTR_FILE) |
| return fuse_do_setattr(entry, attr, attr->ia_file); |
| else |
| return fuse_do_setattr(entry, attr, NULL); |
| } |
| |
| static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry, |
| struct kstat *stat) |
| { |
| struct inode *inode = entry->d_inode; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| |
| if (!fuse_allow_task(fc, current)) |
| return -EACCES; |
| |
| return fuse_update_attributes(inode, stat, NULL, NULL); |
| } |
| |
| static int fuse_setxattr(struct dentry *entry, const char *name, |
| const void *value, size_t size, int flags) |
| { |
| struct inode *inode = entry->d_inode; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_req *req; |
| struct fuse_setxattr_in inarg; |
| int err; |
| |
| if (fc->no_setxattr) |
| return -EOPNOTSUPP; |
| |
| req = fuse_get_req(fc); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.size = size; |
| inarg.flags = flags; |
| req->in.h.opcode = FUSE_SETXATTR; |
| req->in.h.nodeid = get_node_id(inode); |
| 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; |
| fuse_request_send(fc, req); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| if (err == -ENOSYS) { |
| fc->no_setxattr = 1; |
| err = -EOPNOTSUPP; |
| } |
| if (!err) |
| fuse_invalidate_attr(inode); |
| 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 = get_fuse_conn(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_req(fc); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.size = size; |
| req->in.h.opcode = FUSE_GETXATTR; |
| req->in.h.nodeid = get_node_id(inode); |
| 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; |
| } |
| fuse_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 = get_fuse_conn(inode); |
| struct fuse_req *req; |
| struct fuse_getxattr_in inarg; |
| struct fuse_getxattr_out outarg; |
| ssize_t ret; |
| |
| if (!fuse_allow_task(fc, current)) |
| return -EACCES; |
| |
| if (fc->no_listxattr) |
| return -EOPNOTSUPP; |
| |
| req = fuse_get_req(fc); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.size = size; |
| req->in.h.opcode = FUSE_LISTXATTR; |
| req->in.h.nodeid = get_node_id(inode); |
| 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; |
| } |
| fuse_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 = get_fuse_conn(inode); |
| struct fuse_req *req; |
| int err; |
| |
| if (fc->no_removexattr) |
| return -EOPNOTSUPP; |
| |
| req = fuse_get_req(fc); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| req->in.h.opcode = FUSE_REMOVEXATTR; |
| req->in.h.nodeid = get_node_id(inode); |
| req->in.numargs = 1; |
| req->in.args[0].size = strlen(name) + 1; |
| req->in.args[0].value = name; |
| fuse_request_send(fc, req); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| if (err == -ENOSYS) { |
| fc->no_removexattr = 1; |
| err = -EOPNOTSUPP; |
| } |
| if (!err) |
| fuse_invalidate_attr(inode); |
| return err; |
| } |
| |
| 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_rename, |
| .link = fuse_link, |
| .setattr = fuse_setattr, |
| .create = fuse_create, |
| .atomic_open = fuse_atomic_open, |
| .mknod = fuse_mknod, |
| .permission = fuse_permission, |
| .getattr = fuse_getattr, |
| .setxattr = fuse_setxattr, |
| .getxattr = fuse_getxattr, |
| .listxattr = fuse_listxattr, |
| .removexattr = fuse_removexattr, |
| }; |
| |
| static const struct file_operations fuse_dir_operations = { |
| .llseek = generic_file_llseek, |
| .read = generic_read_dir, |
| .readdir = 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, |
| .setxattr = fuse_setxattr, |
| .getxattr = fuse_getxattr, |
| .listxattr = fuse_listxattr, |
| .removexattr = fuse_removexattr, |
| }; |
| |
| static const struct inode_operations fuse_symlink_inode_operations = { |
| .setattr = fuse_setattr, |
| .follow_link = fuse_follow_link, |
| .put_link = fuse_put_link, |
| .readlink = generic_readlink, |
| .getattr = fuse_getattr, |
| .setxattr = fuse_setxattr, |
| .getxattr = fuse_getxattr, |
| .listxattr = fuse_listxattr, |
| .removexattr = fuse_removexattr, |
| }; |
| |
| 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; |
| } |