| /* |
| FUSE: Filesystem in Userspace |
| Copyright (C) 2001-2006 Miklos Szeredi <miklos@szeredi.hu> |
| |
| This program can be distributed under the terms of the GNU GPL. |
| See the file COPYING. |
| */ |
| |
| #include "fuse_i.h" |
| |
| #include <linux/pagemap.h> |
| #include <linux/file.h> |
| #include <linux/gfp.h> |
| #include <linux/sched.h> |
| #include <linux/namei.h> |
| |
| #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_timeout(struct dentry *entry, struct fuse_entry_out *o) |
| { |
| fuse_dentry_settime(entry, |
| time_to_jiffies(o->entry_valid, o->entry_valid_nsec)); |
| if (entry->d_inode) |
| get_fuse_inode(entry->d_inode)->i_time = |
| 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) |
| */ |
| static 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_req *req, struct inode *dir, |
| struct dentry *entry, |
| struct fuse_entry_out *outarg) |
| { |
| req->in.h.opcode = FUSE_LOOKUP; |
| req->in.h.nodeid = get_node_id(dir); |
| req->in.numargs = 1; |
| req->in.args[0].size = entry->d_name.len + 1; |
| req->in.args[0].value = entry->d_name.name; |
| req->out.numargs = 1; |
| req->out.args[0].size = sizeof(struct fuse_entry_out); |
| req->out.args[0].value = outarg; |
| } |
| |
| /* |
| * 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, struct nameidata *nd) |
| { |
| struct inode *inode = 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; |
| |
| /* Doesn't hurt to "reset" the validity timeout */ |
| fuse_invalidate_entry_cache(entry); |
| |
| /* For negative dentries, always do a fresh lookup */ |
| if (!inode) |
| return 0; |
| |
| fc = get_fuse_conn(inode); |
| req = fuse_get_req(fc); |
| if (IS_ERR(req)) |
| return 0; |
| |
| fuse_lookup_init(req, entry->d_parent->d_inode, entry, &outarg); |
| request_send(fc, req); |
| err = req->out.h.error; |
| /* 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_send_forget(fc, req, outarg.nodeid, 1); |
| return 0; |
| } |
| fi->nlookup ++; |
| } |
| fuse_put_request(fc, req); |
| if (err || (outarg.attr.mode ^ inode->i_mode) & S_IFMT) |
| return 0; |
| |
| fuse_change_attributes(inode, &outarg.attr); |
| fuse_change_timeout(entry, &outarg); |
| } |
| return 1; |
| } |
| |
| /* |
| * Check if there's already a hashed alias of this directory inode. |
| * If yes, then lookup and mkdir must not create a new alias. |
| */ |
| static int dir_alias(struct inode *inode) |
| { |
| if (S_ISDIR(inode->i_mode)) { |
| struct dentry *alias = d_find_alias(inode); |
| if (alias) { |
| dput(alias); |
| return 1; |
| } |
| } |
| return 0; |
| } |
| |
| static int invalid_nodeid(u64 nodeid) |
| { |
| return !nodeid || nodeid == FUSE_ROOT_ID; |
| } |
| |
| static struct dentry_operations fuse_dentry_operations = { |
| .d_revalidate = fuse_dentry_revalidate, |
| }; |
| |
| static int valid_mode(int m) |
| { |
| return S_ISREG(m) || S_ISDIR(m) || S_ISLNK(m) || S_ISCHR(m) || |
| S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m); |
| } |
| |
| static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, |
| struct nameidata *nd) |
| { |
| int err; |
| struct fuse_entry_out outarg; |
| struct inode *inode = NULL; |
| struct fuse_conn *fc = get_fuse_conn(dir); |
| struct fuse_req *req; |
| |
| if (entry->d_name.len > FUSE_NAME_MAX) |
| return ERR_PTR(-ENAMETOOLONG); |
| |
| req = fuse_get_req(fc); |
| if (IS_ERR(req)) |
| return ERR_PTR(PTR_ERR(req)); |
| |
| fuse_lookup_init(req, dir, entry, &outarg); |
| request_send(fc, req); |
| err = req->out.h.error; |
| /* Zero nodeid is same as -ENOENT, but with valid timeout */ |
| if (!err && outarg.nodeid && |
| (invalid_nodeid(outarg.nodeid) || !valid_mode(outarg.attr.mode))) |
| err = -EIO; |
| if (!err && outarg.nodeid) { |
| inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation, |
| &outarg.attr); |
| if (!inode) { |
| fuse_send_forget(fc, req, outarg.nodeid, 1); |
| return ERR_PTR(-ENOMEM); |
| } |
| } |
| fuse_put_request(fc, req); |
| if (err && err != -ENOENT) |
| return ERR_PTR(err); |
| |
| if (inode && dir_alias(inode)) { |
| iput(inode); |
| return ERR_PTR(-EIO); |
| } |
| d_add(entry, inode); |
| entry->d_op = &fuse_dentry_operations; |
| if (!err) |
| fuse_change_timeout(entry, &outarg); |
| else |
| fuse_invalidate_entry_cache(entry); |
| return NULL; |
| } |
| |
| /* |
| * Synchronous release for the case when something goes wrong in CREATE_OPEN |
| */ |
| static void fuse_sync_release(struct fuse_conn *fc, struct fuse_file *ff, |
| u64 nodeid, int flags) |
| { |
| struct fuse_req *req; |
| |
| req = fuse_release_fill(ff, nodeid, flags, FUSE_RELEASE); |
| req->force = 1; |
| request_send(fc, req); |
| fuse_put_request(fc, req); |
| } |
| |
| /* |
| * 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, int mode, |
| struct nameidata *nd) |
| { |
| int err; |
| struct inode *inode; |
| struct fuse_conn *fc = get_fuse_conn(dir); |
| struct fuse_req *req; |
| struct fuse_req *forget_req; |
| struct fuse_open_in inarg; |
| struct fuse_open_out outopen; |
| struct fuse_entry_out outentry; |
| struct fuse_file *ff; |
| struct file *file; |
| int flags = nd->intent.open.flags - 1; |
| |
| if (fc->no_create) |
| return -ENOSYS; |
| |
| forget_req = fuse_get_req(fc); |
| if (IS_ERR(forget_req)) |
| return PTR_ERR(forget_req); |
| |
| req = fuse_get_req(fc); |
| err = PTR_ERR(req); |
| if (IS_ERR(req)) |
| goto out_put_forget_req; |
| |
| err = -ENOMEM; |
| ff = fuse_file_alloc(); |
| if (!ff) |
| goto out_put_request; |
| |
| flags &= ~O_NOCTTY; |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.flags = flags; |
| inarg.mode = mode; |
| req->in.h.opcode = FUSE_CREATE; |
| req->in.h.nodeid = get_node_id(dir); |
| req->in.numargs = 2; |
| req->in.args[0].size = sizeof(inarg); |
| req->in.args[0].value = &inarg; |
| req->in.args[1].size = entry->d_name.len + 1; |
| req->in.args[1].value = entry->d_name.name; |
| req->out.numargs = 2; |
| 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; |
| request_send(fc, req); |
| err = req->out.h.error; |
| if (err) { |
| if (err == -ENOSYS) |
| fc->no_create = 1; |
| goto out_free_ff; |
| } |
| |
| err = -EIO; |
| if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid)) |
| goto out_free_ff; |
| |
| fuse_put_request(fc, req); |
| inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation, |
| &outentry.attr); |
| if (!inode) { |
| flags &= ~(O_CREAT | O_EXCL | O_TRUNC); |
| ff->fh = outopen.fh; |
| fuse_sync_release(fc, ff, outentry.nodeid, flags); |
| fuse_send_forget(fc, forget_req, outentry.nodeid, 1); |
| return -ENOMEM; |
| } |
| fuse_put_request(fc, forget_req); |
| d_instantiate(entry, inode); |
| fuse_change_timeout(entry, &outentry); |
| file = lookup_instantiate_filp(nd, entry, generic_file_open); |
| if (IS_ERR(file)) { |
| ff->fh = outopen.fh; |
| fuse_sync_release(fc, ff, outentry.nodeid, flags); |
| return PTR_ERR(file); |
| } |
| fuse_finish_open(inode, file, ff, &outopen); |
| return 0; |
| |
| out_free_ff: |
| fuse_file_free(ff); |
| out_put_request: |
| fuse_put_request(fc, req); |
| out_put_forget_req: |
| fuse_put_request(fc, forget_req); |
| return err; |
| } |
| |
| /* |
| * 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, |
| int mode) |
| { |
| struct fuse_entry_out outarg; |
| struct inode *inode; |
| int err; |
| |
| req->in.h.nodeid = get_node_id(dir); |
| req->out.numargs = 1; |
| req->out.args[0].size = sizeof(outarg); |
| req->out.args[0].value = &outarg; |
| request_send(fc, req); |
| err = req->out.h.error; |
| if (err) { |
| fuse_put_request(fc, req); |
| return err; |
| } |
| err = -EIO; |
| if (invalid_nodeid(outarg.nodeid)) |
| goto out_put_request; |
| |
| if ((outarg.attr.mode ^ mode) & S_IFMT) |
| goto out_put_request; |
| |
| inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation, |
| &outarg.attr); |
| if (!inode) { |
| fuse_send_forget(fc, req, outarg.nodeid, 1); |
| return -ENOMEM; |
| } |
| fuse_put_request(fc, req); |
| |
| if (dir_alias(inode)) { |
| iput(inode); |
| return -EIO; |
| } |
| |
| d_instantiate(entry, inode); |
| fuse_change_timeout(entry, &outarg); |
| fuse_invalidate_attr(dir); |
| return 0; |
| |
| out_put_request: |
| fuse_put_request(fc, req); |
| return err; |
| } |
| |
| static int fuse_mknod(struct inode *dir, struct dentry *entry, int 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); |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.mode = mode; |
| inarg.rdev = new_encode_dev(rdev); |
| req->in.h.opcode = FUSE_MKNOD; |
| 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, mode); |
| } |
| |
| static int fuse_create(struct inode *dir, struct dentry *entry, int mode, |
| struct nameidata *nd) |
| { |
| if (nd && (nd->flags & LOOKUP_CREATE)) { |
| int err = fuse_create_open(dir, entry, mode, nd); |
| if (err != -ENOSYS) |
| return err; |
| /* Fall back on mknod */ |
| } |
| return fuse_mknod(dir, entry, mode, 0); |
| } |
| |
| static int fuse_mkdir(struct inode *dir, struct dentry *entry, int 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); |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| inarg.mode = mode; |
| 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; |
| request_send(fc, req); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| if (!err) { |
| struct inode *inode = entry->d_inode; |
| |
| /* Set nlink to zero so the inode can be cleared, if |
| the inode does have more links this will be |
| discovered at the next lookup/getattr */ |
| inode->i_nlink = 0; |
| fuse_invalidate_attr(inode); |
| fuse_invalidate_attr(dir); |
| fuse_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; |
| request_send(fc, req); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| if (!err) { |
| entry->d_inode->i_nlink = 0; |
| 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; |
| request_send(fc, req); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| if (!err) { |
| fuse_invalidate_attr(olddir); |
| if (olddir != newdir) |
| fuse_invalidate_attr(newdir); |
| |
| /* newent will end up negative */ |
| if (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 || err == -EINTR) |
| fuse_invalidate_attr(inode); |
| return err; |
| } |
| |
| int fuse_do_getattr(struct inode *inode) |
| { |
| int err; |
| struct fuse_attr_out arg; |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| struct fuse_req *req = fuse_get_req(fc); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| req->in.h.opcode = FUSE_GETATTR; |
| req->in.h.nodeid = get_node_id(inode); |
| req->out.numargs = 1; |
| req->out.args[0].size = sizeof(arg); |
| req->out.args[0].value = &arg; |
| request_send(fc, req); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| if (!err) { |
| if ((inode->i_mode ^ arg.attr.mode) & S_IFMT) { |
| make_bad_inode(inode); |
| err = -EIO; |
| } else { |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| fuse_change_attributes(inode, &arg.attr); |
| fi->i_time = time_to_jiffies(arg.attr_valid, |
| arg.attr_valid_nsec); |
| } |
| } |
| return err; |
| } |
| |
| /* |
| * 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. |
| */ |
| static int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task) |
| { |
| if (fc->flags & FUSE_ALLOW_OTHER) |
| return 1; |
| |
| if (task->euid == fc->user_id && |
| task->suid == fc->user_id && |
| task->uid == fc->user_id && |
| task->egid == fc->group_id && |
| task->sgid == fc->group_id && |
| task->gid == fc->group_id) |
| return 1; |
| |
| return 0; |
| } |
| |
| /* |
| * Check whether the inode attributes are still valid |
| * |
| * If the attribute validity timeout has expired, then fetch the fresh |
| * attributes with a 'getattr' request |
| * |
| * I'm not sure why cached attributes are never returned for the root |
| * inode, this is probably being too cautious. |
| */ |
| static int fuse_revalidate(struct dentry *entry) |
| { |
| struct inode *inode = entry->d_inode; |
| struct fuse_inode *fi = get_fuse_inode(inode); |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| |
| if (!fuse_allow_task(fc, current)) |
| return -EACCES; |
| if (get_node_id(inode) != FUSE_ROOT_ID && |
| fi->i_time >= get_jiffies_64()) |
| return 0; |
| |
| return fuse_do_getattr(inode); |
| } |
| |
| 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; |
| 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; |
| 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; |
| } |
| |
| /* |
| * 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 nameidata *nd) |
| { |
| struct fuse_conn *fc = get_fuse_conn(inode); |
| |
| if (!fuse_allow_task(fc, current)) |
| return -EACCES; |
| else if (fc->flags & FUSE_DEFAULT_PERMISSIONS) { |
| int err = generic_permission(inode, mask, NULL); |
| |
| /* If permission is denied, try to refresh file |
| attributes. This is also needed, because the root |
| node will at first have no permissions */ |
| if (err == -EACCES) { |
| err = fuse_do_getattr(inode); |
| if (!err) |
| err = generic_permission(inode, mask, NULL); |
| } |
| |
| /* 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 */ |
| |
| return err; |
| } else { |
| int mode = inode->i_mode; |
| if ((mask & MAY_EXEC) && !S_ISDIR(mode) && !(mode & S_IXUGO)) |
| return -EACCES; |
| |
| if (nd && (nd->flags & (LOOKUP_ACCESS | LOOKUP_CHDIR))) |
| return fuse_access(inode, mask); |
| return 0; |
| } |
| } |
| |
| static int parse_dirfile(char *buf, size_t nbytes, struct file *file, |
| void *dstbuf, filldir_t filldir) |
| { |
| while (nbytes >= FUSE_NAME_OFFSET) { |
| struct fuse_dirent *dirent = (struct fuse_dirent *) buf; |
| size_t reclen = FUSE_DIRENT_SIZE(dirent); |
| int over; |
| if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX) |
| return -EIO; |
| if (reclen > nbytes) |
| break; |
| |
| over = filldir(dstbuf, dirent->name, dirent->namelen, |
| file->f_pos, dirent->ino, dirent->type); |
| if (over) |
| break; |
| |
| buf += reclen; |
| nbytes -= reclen; |
| file->f_pos = dirent->off; |
| } |
| |
| return 0; |
| } |
| |
| static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir) |
| { |
| int err; |
| size_t nbytes; |
| struct page *page; |
| struct inode *inode = file->f_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->num_pages = 1; |
| req->pages[0] = page; |
| fuse_read_fill(req, file, inode, file->f_pos, PAGE_SIZE, FUSE_READDIR); |
| 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_PTR(PTR_ERR(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; |
| 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, 1); |
| } |
| |
| static int fuse_dir_release(struct inode *inode, struct file *file) |
| { |
| return fuse_release_common(inode, file, 1); |
| } |
| |
| static int fuse_dir_fsync(struct file *file, struct dentry *de, int datasync) |
| { |
| /* nfsd can call this with no file */ |
| return file ? fuse_fsync_common(file, de, datasync, 1) : 0; |
| } |
| |
| 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; |
| /* You can only _set_ these together (they may change by themselves) */ |
| if ((ivalid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME)) { |
| arg->valid |= FATTR_ATIME | FATTR_MTIME; |
| arg->atime = iattr->ia_atime.tv_sec; |
| arg->mtime = iattr->ia_mtime.tv_sec; |
| } |
| if (ivalid & ATTR_FILE) { |
| struct fuse_file *ff = iattr->ia_file->private_data; |
| arg->valid |= FATTR_FH; |
| arg->fh = ff->fh; |
| } |
| } |
| |
| /* |
| * 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 by hand and call vmtruncate() only after the file has |
| * actually been truncated. |
| */ |
| static int fuse_setattr(struct dentry *entry, struct iattr *attr) |
| { |
| 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; |
| int err; |
| int is_truncate = 0; |
| |
| if (fc->flags & FUSE_DEFAULT_PERMISSIONS) { |
| err = inode_change_ok(inode, attr); |
| if (err) |
| return err; |
| } |
| |
| if (attr->ia_valid & ATTR_SIZE) { |
| unsigned long limit; |
| is_truncate = 1; |
| limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; |
| if (limit != RLIM_INFINITY && attr->ia_size > (loff_t) limit) { |
| send_sig(SIGXFSZ, current, 0); |
| return -EFBIG; |
| } |
| } |
| |
| req = fuse_get_req(fc); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| |
| memset(&inarg, 0, sizeof(inarg)); |
| iattr_to_fattr(attr, &inarg); |
| 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; |
| req->out.args[0].size = sizeof(outarg); |
| req->out.args[0].value = &outarg; |
| request_send(fc, req); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| if (!err) { |
| if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) { |
| make_bad_inode(inode); |
| err = -EIO; |
| } else { |
| if (is_truncate) { |
| loff_t origsize = i_size_read(inode); |
| i_size_write(inode, outarg.attr.size); |
| if (origsize > outarg.attr.size) |
| vmtruncate(inode, outarg.attr.size); |
| } |
| fuse_change_attributes(inode, &outarg.attr); |
| fi->i_time = time_to_jiffies(outarg.attr_valid, |
| outarg.attr_valid_nsec); |
| } |
| } else if (err == -EINTR) |
| fuse_invalidate_attr(inode); |
| |
| return err; |
| } |
| |
| static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry, |
| struct kstat *stat) |
| { |
| struct inode *inode = entry->d_inode; |
| int err = fuse_revalidate(entry); |
| if (!err) |
| generic_fillattr(inode, stat); |
| |
| return err; |
| } |
| |
| static 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; |
| request_send(fc, req); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| if (err == -ENOSYS) { |
| fc->no_setxattr = 1; |
| err = -EOPNOTSUPP; |
| } |
| 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; |
| } |
| 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 (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; |
| } |
| 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; |
| request_send(fc, req); |
| err = req->out.h.error; |
| fuse_put_request(fc, req); |
| if (err == -ENOSYS) { |
| fc->no_removexattr = 1; |
| err = -EOPNOTSUPP; |
| } |
| return err; |
| } |
| |
| static 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, |
| .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, |
| }; |
| |
| static 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 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; |
| } |