diff options
Diffstat (limited to 'fs/fuse/dir.c')
| -rw-r--r-- | fs/fuse/dir.c | 1931 |
1 files changed, 1931 insertions, 0 deletions
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c new file mode 100644 index 000000000..6098e0c7f --- /dev/null +++ b/fs/fuse/dir.c @@ -0,0 +1,1931 @@ +/* + 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 && fuse_is_bad(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 || fuse_invalid_attr(&outarg.attr) || + (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); +} + +bool fuse_invalid_attr(struct fuse_attr *attr) +{ + return !fuse_valid_type(attr->mode) || + attr->size > LLONG_MAX; +} + +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_invalid_attr(&outarg->attr)) + 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; + bool locked; + + if (fuse_is_bad(dir)) + return ERR_PTR(-EIO); + + locked = fuse_lock_inode(dir); + err = fuse_lookup_name(dir->i_sb, get_node_id(dir), &entry->d_name, + &outarg, &inode); + fuse_unlock_inode(dir, locked); + 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 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) || + fuse_invalid_attr(&outentry.attr)) + 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 err; + struct fuse_conn *fc = get_fuse_conn(dir); + struct dentry *res = NULL; + + if (fuse_is_bad(dir)) + return -EIO; + + 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); + 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; + struct dentry *d; + int err; + struct fuse_forget_link *forget; + + if (fuse_is_bad(dir)) + return -EIO; + + 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) || fuse_invalid_attr(&outarg.attr)) + 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); + + d_drop(entry); + d = d_splice_alias(inode, entry); + if (IS_ERR(d)) + return PTR_ERR(d); + + if (d) { + fuse_change_entry_timeout(d, &outarg); + dput(d); + } else { + 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); + + if (fuse_is_bad(dir)) + return -EIO; + + 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); + + if (fuse_is_bad(dir)) + return -EIO; + + 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 (fuse_is_bad(olddir)) + return -EIO; + + 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; + if (likely(inode->i_nlink < UINT_MAX)) + 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 (fuse_invalid_attr(&outarg.attr) || + (inode->i_mode ^ outarg.attr.mode) & S_IFMT) { + fuse_make_bad(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_nested(parent, I_MUTEX_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_is_bad(inode)) + return -EIO; + + 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_invalid_attr(&o->attr)) + 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 (fuse_is_bad(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; + bool locked; + + if (fuse_is_bad(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); + } + locked = fuse_lock_inode(inode); + fuse_request_send(fc, req); + fuse_unlock_inode(inode, locked); + 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); + + if (fuse_is_bad(inode)) + return ERR_PTR(-EIO); + + 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, true); + + 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; + + /* Flush dirty data/metadata before non-truncate SETATTR */ + if (is_wb && S_ISREG(inode->i_mode) && + attr->ia_valid & + (ATTR_MODE | ATTR_UID | ATTR_GID | ATTR_MTIME_SET | + ATTR_TIMES_SET)) { + err = write_inode_now(inode, true); + if (err) + return err; + + fuse_set_nowrite(inode); + fuse_release_nowrite(inode); + } + + 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 (fuse_invalid_attr(&outarg.attr) || + (inode->i_mode ^ outarg.attr.mode) & S_IFMT) { + fuse_make_bad(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_is_bad(inode)) + return -EIO; + + 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_is_bad(inode)) + return -EIO; + + 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; +} |