[Feature]add MT2731_MP2_MR2_SVN388 baseline version
Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/fs/fuse/dir.c b/src/kernel/linux/v4.14/fs/fuse/dir.c
new file mode 100644
index 0000000..d84819c
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/fuse/dir.c
@@ -0,0 +1,1932 @@
+/*
+ FUSE: Filesystem in Userspace
+ Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
+
+ This program can be distributed under the terms of the GNU GPL.
+ See the file COPYING.
+*/
+
+#include "fuse_i.h"
+
+#include <linux/pagemap.h>
+#include <linux/file.h>
+#include <linux/sched.h>
+#include <linux/namei.h>
+#include <linux/slab.h>
+#include <linux/xattr.h>
+#include <linux/posix_acl.h>
+
+static bool fuse_use_readdirplus(struct inode *dir, struct dir_context *ctx)
+{
+ struct fuse_conn *fc = get_fuse_conn(dir);
+ struct fuse_inode *fi = get_fuse_inode(dir);
+
+ if (!fc->do_readdirplus)
+ return false;
+ if (!fc->readdirplus_auto)
+ return true;
+ if (test_and_clear_bit(FUSE_I_ADVISE_RDPLUS, &fi->state))
+ return true;
+ if (ctx->pos == 0)
+ return true;
+ return false;
+}
+
+static void fuse_advise_use_readdirplus(struct inode *dir)
+{
+ struct fuse_inode *fi = get_fuse_inode(dir);
+
+ set_bit(FUSE_I_ADVISE_RDPLUS, &fi->state);
+}
+
+union fuse_dentry {
+ u64 time;
+ struct rcu_head rcu;
+};
+
+static inline void fuse_dentry_settime(struct dentry *entry, u64 time)
+{
+ ((union fuse_dentry *) entry->d_fsdata)->time = time;
+}
+
+static inline u64 fuse_dentry_time(struct dentry *entry)
+{
+ return ((union fuse_dentry *) entry->d_fsdata)->time;
+}
+
+/*
+ * FUSE caches dentries and attributes with separate timeout. The
+ * time in jiffies until the dentry/attributes are valid is stored in
+ * dentry->d_fsdata and fuse_inode->i_time respectively.
+ */
+
+/*
+ * Calculate the time in jiffies until a dentry/attributes are valid
+ */
+static u64 time_to_jiffies(u64 sec, u32 nsec)
+{
+ if (sec || nsec) {
+ struct timespec64 ts = {
+ sec,
+ min_t(u32, nsec, NSEC_PER_SEC - 1)
+ };
+
+ return get_jiffies_64() + timespec64_to_jiffies(&ts);
+ } else
+ return 0;
+}
+
+/*
+ * Set dentry and possibly attribute timeouts from the lookup/mk*
+ * replies
+ */
+static void fuse_change_entry_timeout(struct dentry *entry,
+ struct fuse_entry_out *o)
+{
+ fuse_dentry_settime(entry,
+ time_to_jiffies(o->entry_valid, o->entry_valid_nsec));
+}
+
+static u64 attr_timeout(struct fuse_attr_out *o)
+{
+ return time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
+}
+
+static u64 entry_attr_timeout(struct fuse_entry_out *o)
+{
+ return time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
+}
+
+/*
+ * Mark the attributes as stale, so that at the next call to
+ * ->getattr() they will be fetched from userspace
+ */
+void fuse_invalidate_attr(struct inode *inode)
+{
+ get_fuse_inode(inode)->i_time = 0;
+}
+
+/**
+ * Mark the attributes as stale due to an atime change. Avoid the invalidate if
+ * atime is not used.
+ */
+void fuse_invalidate_atime(struct inode *inode)
+{
+ if (!IS_RDONLY(inode))
+ fuse_invalidate_attr(inode);
+}
+
+/*
+ * Just mark the entry as stale, so that a next attempt to look it up
+ * will result in a new lookup call to userspace
+ *
+ * This is called when a dentry is about to become negative and the
+ * timeout is unknown (unlink, rmdir, rename and in some cases
+ * lookup)
+ */
+void fuse_invalidate_entry_cache(struct dentry *entry)
+{
+ fuse_dentry_settime(entry, 0);
+}
+
+/*
+ * Same as fuse_invalidate_entry_cache(), but also try to remove the
+ * dentry from the hash
+ */
+static void fuse_invalidate_entry(struct dentry *entry)
+{
+ d_invalidate(entry);
+ fuse_invalidate_entry_cache(entry);
+}
+
+static void fuse_lookup_init(struct fuse_conn *fc, struct fuse_args *args,
+ u64 nodeid, const struct qstr *name,
+ struct fuse_entry_out *outarg)
+{
+ memset(outarg, 0, sizeof(struct fuse_entry_out));
+ args->in.h.opcode = FUSE_LOOKUP;
+ args->in.h.nodeid = nodeid;
+ args->in.numargs = 1;
+ args->in.args[0].size = name->len + 1;
+ args->in.args[0].value = name->name;
+ args->out.numargs = 1;
+ args->out.args[0].size = sizeof(struct fuse_entry_out);
+ args->out.args[0].value = outarg;
+}
+
+u64 fuse_get_attr_version(struct fuse_conn *fc)
+{
+ u64 curr_version;
+
+ /*
+ * The spin lock isn't actually needed on 64bit archs, but we
+ * don't yet care too much about such optimizations.
+ */
+ spin_lock(&fc->lock);
+ curr_version = fc->attr_version;
+ spin_unlock(&fc->lock);
+
+ return curr_version;
+}
+
+/*
+ * Check whether the dentry is still valid
+ *
+ * If the entry validity timeout has expired and the dentry is
+ * positive, try to redo the lookup. If the lookup results in a
+ * different inode, then let the VFS invalidate the dentry and redo
+ * the lookup once more. If the lookup results in the same inode,
+ * then refresh the attributes, timeouts and mark the dentry valid.
+ */
+static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
+{
+ struct inode *inode;
+ struct dentry *parent;
+ struct fuse_conn *fc;
+ struct fuse_inode *fi;
+ int ret;
+
+ inode = d_inode_rcu(entry);
+ if (inode && is_bad_inode(inode))
+ goto invalid;
+ else if (time_before64(fuse_dentry_time(entry), get_jiffies_64()) ||
+ (flags & LOOKUP_REVAL)) {
+ struct fuse_entry_out outarg;
+ FUSE_ARGS(args);
+ struct fuse_forget_link *forget;
+ u64 attr_version;
+
+ /* For negative dentries, always do a fresh lookup */
+ if (!inode)
+ goto invalid;
+
+ ret = -ECHILD;
+ if (flags & LOOKUP_RCU)
+ goto out;
+
+ fc = get_fuse_conn(inode);
+
+ forget = fuse_alloc_forget();
+ ret = -ENOMEM;
+ if (!forget)
+ goto out;
+
+ attr_version = fuse_get_attr_version(fc);
+
+ parent = dget_parent(entry);
+ fuse_lookup_init(fc, &args, get_node_id(d_inode(parent)),
+ &entry->d_name, &outarg);
+ ret = fuse_simple_request(fc, &args);
+ dput(parent);
+ /* Zero nodeid is same as -ENOENT */
+ if (!ret && !outarg.nodeid)
+ ret = -ENOENT;
+ if (!ret) {
+ fi = get_fuse_inode(inode);
+ if (outarg.nodeid != get_node_id(inode)) {
+ fuse_queue_forget(fc, forget, outarg.nodeid, 1);
+ goto invalid;
+ }
+ spin_lock(&fc->lock);
+ fi->nlookup++;
+ spin_unlock(&fc->lock);
+ }
+ kfree(forget);
+ if (ret == -ENOMEM)
+ goto out;
+ if (ret || 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;
+}
+
+/*
+ * 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, 1);
+ 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;
+}
+
+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,
+ .d_canonical_path = fuse_dentry_canonical_path,
+};
+
+const struct dentry_operations fuse_root_dentry_operations = {
+ .d_init = fuse_dentry_init,
+ .d_release = fuse_dentry_release,
+ .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);
+}
+
+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;
+
+ 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 *opened)
+{
+ int err;
+ struct inode *inode;
+ struct fuse_conn *fc = get_fuse_conn(dir);
+ FUSE_ARGS(args);
+ struct fuse_forget_link *forget;
+ struct fuse_create_in inarg;
+ struct fuse_open_out outopen;
+ struct fuse_entry_out outentry;
+ struct fuse_file *ff;
+
+ /* Userspace expects S_IFREG in create mode */
+ BUG_ON((mode & S_IFMT) != S_IFREG);
+
+ forget = fuse_alloc_forget();
+ err = -ENOMEM;
+ if (!forget)
+ goto out_err;
+
+ err = -ENOMEM;
+ ff = fuse_file_alloc(fc);
+ if (!ff)
+ goto out_put_forget_req;
+
+ if (!fc->dont_mask)
+ mode &= ~current_umask();
+
+ flags &= ~O_NOCTTY;
+ memset(&inarg, 0, sizeof(inarg));
+ memset(&outentry, 0, sizeof(outentry));
+ inarg.flags = flags;
+ inarg.mode = mode;
+ inarg.umask = current_umask();
+ args.in.h.opcode = FUSE_CREATE;
+ args.in.h.nodeid = get_node_id(dir);
+ args.in.numargs = 2;
+ args.in.args[0].size = sizeof(inarg);
+ args.in.args[0].value = &inarg;
+ args.in.args[1].size = entry->d_name.len + 1;
+ args.in.args[1].value = entry->d_name.name;
+ args.out.numargs = 2;
+ args.out.args[0].size = sizeof(outentry);
+ args.out.args[0].value = &outentry;
+ args.out.args[1].size = sizeof(outopen);
+ args.out.args[1].value = &outopen;
+ err = fuse_simple_request(fc, &args);
+ if (err)
+ goto out_free_ff;
+
+ err = -EIO;
+ if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid) ||
+ 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, opened);
+ if (err) {
+ fuse_sync_release(ff, flags);
+ } else {
+ file->private_data = ff;
+ fuse_finish_open(inode, file);
+ }
+ return err;
+
+out_free_ff:
+ fuse_file_free(ff);
+out_put_forget_req:
+ kfree(forget);
+out_err:
+ return err;
+}
+
+static int fuse_mknod(struct inode *, struct dentry *, umode_t, dev_t);
+static int fuse_atomic_open(struct inode *dir, struct dentry *entry,
+ struct file *file, unsigned flags,
+ umode_t mode, int *opened)
+{
+ int err;
+ struct fuse_conn *fc = get_fuse_conn(dir);
+ struct dentry *res = NULL;
+
+ if (d_in_lookup(entry)) {
+ res = fuse_lookup(dir, entry, 0);
+ if (IS_ERR(res))
+ return PTR_ERR(res);
+
+ if (res)
+ entry = res;
+ }
+
+ if (!(flags & O_CREAT) || d_really_is_positive(entry))
+ goto no_open;
+
+ /* Only creates */
+ *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_args *args,
+ struct inode *dir, struct dentry *entry,
+ umode_t mode)
+{
+ struct fuse_entry_out outarg;
+ struct inode *inode;
+ int err;
+ struct fuse_forget_link *forget;
+
+ forget = fuse_alloc_forget();
+ if (!forget)
+ return -ENOMEM;
+
+ memset(&outarg, 0, sizeof(outarg));
+ args->in.h.nodeid = get_node_id(dir);
+ args->out.numargs = 1;
+ args->out.args[0].size = sizeof(outarg);
+ args->out.args[0].value = &outarg;
+ err = fuse_simple_request(fc, args);
+ if (err)
+ goto out_put_forget_req;
+
+ err = -EIO;
+ if (invalid_nodeid(outarg.nodeid) || 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);
+
+ err = d_instantiate_no_diralias(entry, inode);
+ if (err)
+ return err;
+
+ fuse_change_entry_timeout(entry, &outarg);
+ fuse_invalidate_attr(dir);
+ return 0;
+
+ out_put_forget_req:
+ kfree(forget);
+ return err;
+}
+
+static int fuse_mknod(struct inode *dir, struct dentry *entry, umode_t mode,
+ dev_t rdev)
+{
+ struct fuse_mknod_in inarg;
+ struct fuse_conn *fc = get_fuse_conn(dir);
+ FUSE_ARGS(args);
+
+ if (!fc->dont_mask)
+ mode &= ~current_umask();
+
+ memset(&inarg, 0, sizeof(inarg));
+ inarg.mode = mode;
+ inarg.rdev = new_encode_dev(rdev);
+ inarg.umask = current_umask();
+ args.in.h.opcode = FUSE_MKNOD;
+ args.in.numargs = 2;
+ args.in.args[0].size = sizeof(inarg);
+ args.in.args[0].value = &inarg;
+ args.in.args[1].size = entry->d_name.len + 1;
+ args.in.args[1].value = entry->d_name.name;
+ return create_new_entry(fc, &args, dir, entry, mode);
+}
+
+static int fuse_create(struct inode *dir, struct dentry *entry, umode_t mode,
+ bool excl)
+{
+ return fuse_mknod(dir, entry, mode, 0);
+}
+
+static int fuse_mkdir(struct inode *dir, struct dentry *entry, umode_t mode)
+{
+ struct fuse_mkdir_in inarg;
+ struct fuse_conn *fc = get_fuse_conn(dir);
+ FUSE_ARGS(args);
+
+ if (!fc->dont_mask)
+ mode &= ~current_umask();
+
+ memset(&inarg, 0, sizeof(inarg));
+ inarg.mode = mode;
+ inarg.umask = current_umask();
+ args.in.h.opcode = FUSE_MKDIR;
+ args.in.numargs = 2;
+ args.in.args[0].size = sizeof(inarg);
+ args.in.args[0].value = &inarg;
+ args.in.args[1].size = entry->d_name.len + 1;
+ args.in.args[1].value = entry->d_name.name;
+ return create_new_entry(fc, &args, dir, entry, S_IFDIR);
+}
+
+static int fuse_symlink(struct inode *dir, struct dentry *entry,
+ const char *link)
+{
+ struct fuse_conn *fc = get_fuse_conn(dir);
+ unsigned len = strlen(link) + 1;
+ FUSE_ARGS(args);
+
+ args.in.h.opcode = FUSE_SYMLINK;
+ args.in.numargs = 2;
+ args.in.args[0].size = entry->d_name.len + 1;
+ args.in.args[0].value = entry->d_name.name;
+ args.in.args[1].size = len;
+ args.in.args[1].value = link;
+ return create_new_entry(fc, &args, dir, entry, S_IFLNK);
+}
+
+void fuse_update_ctime(struct inode *inode)
+{
+ if (!IS_NOCMTIME(inode)) {
+ inode->i_ctime = current_time(inode);
+ mark_inode_dirty_sync(inode);
+ }
+}
+
+static int fuse_unlink(struct inode *dir, struct dentry *entry)
+{
+ int err;
+ struct fuse_conn *fc = get_fuse_conn(dir);
+ FUSE_ARGS(args);
+
+ args.in.h.opcode = FUSE_UNLINK;
+ args.in.h.nodeid = get_node_id(dir);
+ args.in.numargs = 1;
+ args.in.args[0].size = entry->d_name.len + 1;
+ args.in.args[0].value = entry->d_name.name;
+ err = fuse_simple_request(fc, &args);
+ if (!err) {
+ struct inode *inode = d_inode(entry);
+ struct fuse_inode *fi = get_fuse_inode(inode);
+
+ spin_lock(&fc->lock);
+ fi->attr_version = ++fc->attr_version;
+ /*
+ * If i_nlink == 0 then unlink doesn't make sense, yet this can
+ * happen if userspace filesystem is careless. It would be
+ * difficult to enforce correct nlink usage so just ignore this
+ * condition here
+ */
+ if (inode->i_nlink > 0)
+ drop_nlink(inode);
+ spin_unlock(&fc->lock);
+ fuse_invalidate_attr(inode);
+ fuse_invalidate_attr(dir);
+ fuse_invalidate_entry_cache(entry);
+ fuse_update_ctime(inode);
+ } else if (err == -EINTR)
+ fuse_invalidate_entry(entry);
+ return err;
+}
+
+static int fuse_rmdir(struct inode *dir, struct dentry *entry)
+{
+ int err;
+ struct fuse_conn *fc = get_fuse_conn(dir);
+ FUSE_ARGS(args);
+
+ args.in.h.opcode = FUSE_RMDIR;
+ args.in.h.nodeid = get_node_id(dir);
+ args.in.numargs = 1;
+ args.in.args[0].size = entry->d_name.len + 1;
+ args.in.args[0].value = entry->d_name.name;
+ err = fuse_simple_request(fc, &args);
+ if (!err) {
+ clear_nlink(d_inode(entry));
+ fuse_invalidate_attr(dir);
+ fuse_invalidate_entry_cache(entry);
+ } else if (err == -EINTR)
+ fuse_invalidate_entry(entry);
+ return err;
+}
+
+static int fuse_rename_common(struct inode *olddir, struct dentry *oldent,
+ struct inode *newdir, struct dentry *newent,
+ unsigned int flags, int opcode, size_t argsize)
+{
+ int err;
+ struct fuse_rename2_in inarg;
+ struct fuse_conn *fc = get_fuse_conn(olddir);
+ FUSE_ARGS(args);
+
+ memset(&inarg, 0, argsize);
+ inarg.newdir = get_node_id(newdir);
+ inarg.flags = flags;
+ args.in.h.opcode = opcode;
+ args.in.h.nodeid = get_node_id(olddir);
+ args.in.numargs = 3;
+ args.in.args[0].size = argsize;
+ args.in.args[0].value = &inarg;
+ args.in.args[1].size = oldent->d_name.len + 1;
+ args.in.args[1].value = oldent->d_name.name;
+ args.in.args[2].size = newent->d_name.len + 1;
+ args.in.args[2].value = newent->d_name.name;
+ err = fuse_simple_request(fc, &args);
+ if (!err) {
+ /* ctime changes */
+ fuse_invalidate_attr(d_inode(oldent));
+ fuse_update_ctime(d_inode(oldent));
+
+ if (flags & RENAME_EXCHANGE) {
+ fuse_invalidate_attr(d_inode(newent));
+ fuse_update_ctime(d_inode(newent));
+ }
+
+ fuse_invalidate_attr(olddir);
+ if (olddir != newdir)
+ fuse_invalidate_attr(newdir);
+
+ /* newent will end up negative */
+ if (!(flags & RENAME_EXCHANGE) && d_really_is_positive(newent)) {
+ fuse_invalidate_attr(d_inode(newent));
+ fuse_invalidate_entry_cache(newent);
+ fuse_update_ctime(d_inode(newent));
+ }
+ } else if (err == -EINTR) {
+ /* If request was interrupted, DEITY only knows if the
+ rename actually took place. If the invalidation
+ fails (e.g. some process has CWD under the renamed
+ directory), then there can be inconsistency between
+ the dcache and the real filesystem. Tough luck. */
+ fuse_invalidate_entry(oldent);
+ if (d_really_is_positive(newent))
+ fuse_invalidate_entry(newent);
+ }
+
+ return err;
+}
+
+static int fuse_rename2(struct inode *olddir, struct dentry *oldent,
+ struct inode *newdir, struct dentry *newent,
+ unsigned int flags)
+{
+ struct fuse_conn *fc = get_fuse_conn(olddir);
+ int err;
+
+ if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
+ return -EINVAL;
+
+ if (flags) {
+ if (fc->no_rename2 || fc->minor < 23)
+ return -EINVAL;
+
+ err = fuse_rename_common(olddir, oldent, newdir, newent, flags,
+ FUSE_RENAME2,
+ sizeof(struct fuse_rename2_in));
+ if (err == -ENOSYS) {
+ fc->no_rename2 = 1;
+ err = -EINVAL;
+ }
+ } else {
+ err = fuse_rename_common(olddir, oldent, newdir, newent, 0,
+ FUSE_RENAME,
+ sizeof(struct fuse_rename_in));
+ }
+
+ return err;
+}
+
+static int fuse_link(struct dentry *entry, struct inode *newdir,
+ struct dentry *newent)
+{
+ int err;
+ struct fuse_link_in inarg;
+ struct inode *inode = d_inode(entry);
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ FUSE_ARGS(args);
+
+ memset(&inarg, 0, sizeof(inarg));
+ inarg.oldnodeid = get_node_id(inode);
+ args.in.h.opcode = FUSE_LINK;
+ args.in.numargs = 2;
+ args.in.args[0].size = sizeof(inarg);
+ args.in.args[0].value = &inarg;
+ args.in.args[1].size = newent->d_name.len + 1;
+ args.in.args[1].value = newent->d_name.name;
+ err = create_new_entry(fc, &args, newdir, newent, inode->i_mode);
+ /* Contrary to "normal" filesystems it can happen that link
+ makes two "logical" inodes point to the same "physical"
+ inode. We invalidate the attributes of the old one, so it
+ will reflect changes in the backing inode (link count,
+ etc.)
+ */
+ if (!err) {
+ struct fuse_inode *fi = get_fuse_inode(inode);
+
+ spin_lock(&fc->lock);
+ fi->attr_version = ++fc->attr_version;
+ 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(&init_user_ns, attr->uid);
+ stat->gid = make_kgid(&init_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) {
+ make_bad_inode(inode);
+ err = -EIO;
+ } else {
+ fuse_change_attributes(inode, &outarg.attr,
+ attr_timeout(&outarg),
+ attr_version);
+ if (stat)
+ fuse_fillattr(inode, &outarg.attr, stat);
+ }
+ }
+ return err;
+}
+
+static int fuse_update_get_attr(struct inode *inode, struct file *file,
+ struct kstat *stat)
+{
+ struct fuse_inode *fi = get_fuse_inode(inode);
+ int err = 0;
+
+ if (time_before64(fi->i_time, get_jiffies_64())) {
+ 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);
+}
+
+int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
+ u64 child_nodeid, struct qstr *name)
+{
+ int err = -ENOTDIR;
+ struct inode *parent;
+ struct dentry *dir;
+ struct dentry *entry;
+
+ parent = ilookup5(sb, parent_nodeid, fuse_inode_eq, &parent_nodeid);
+ if (!parent)
+ return -ENOENT;
+
+ inode_lock(parent);
+ if (!S_ISDIR(parent->i_mode))
+ goto unlock;
+
+ err = -ENOENT;
+ dir = d_find_alias(parent);
+ if (!dir)
+ goto unlock;
+
+ name->hash = full_name_hash(dir, name->name, name->len);
+ entry = d_lookup(dir, name);
+ dput(dir);
+ if (!entry)
+ goto unlock;
+
+ fuse_invalidate_attr(parent);
+ fuse_invalidate_entry(entry);
+
+ if (child_nodeid != 0 && d_really_is_positive(entry)) {
+ inode_lock(d_inode(entry));
+ if (get_node_id(d_inode(entry)) != child_nodeid) {
+ err = -ENOENT;
+ goto badentry;
+ }
+ if (d_mountpoint(entry)) {
+ err = -EBUSY;
+ goto badentry;
+ }
+ if (d_is_dir(entry)) {
+ shrink_dcache_parent(entry);
+ if (!simple_empty(entry)) {
+ err = -ENOTEMPTY;
+ goto badentry;
+ }
+ d_inode(entry)->i_flags |= S_DEAD;
+ }
+ dont_mount(entry);
+ clear_nlink(d_inode(entry));
+ err = 0;
+ badentry:
+ inode_unlock(d_inode(entry));
+ if (!err)
+ d_delete(entry);
+ } else {
+ err = 0;
+ }
+ dput(entry);
+
+ unlock:
+ inode_unlock(parent);
+ iput(parent);
+ return err;
+}
+
+/*
+ * Calling into a user-controlled filesystem gives the filesystem
+ * daemon ptrace-like capabilities over the current process. This
+ * means, that the filesystem daemon is able to record the exact
+ * filesystem operations performed, and can also control the behavior
+ * of the requester process in otherwise impossible ways. For example
+ * it can delay the operation for arbitrary length of time allowing
+ * DoS against the requester.
+ *
+ * For this reason only those processes can call into the filesystem,
+ * for which the owner of the mount has ptrace privilege. This
+ * excludes processes started by other users, suid or sgid processes.
+ */
+int fuse_allow_current_process(struct fuse_conn *fc)
+{
+ const struct cred *cred;
+
+ if (fc->allow_other)
+ return 1;
+
+ cred = current_cred();
+ if (uid_eq(cred->euid, fc->user_id) &&
+ uid_eq(cred->suid, fc->user_id) &&
+ uid_eq(cred->uid, fc->user_id) &&
+ gid_eq(cred->egid, fc->group_id) &&
+ gid_eq(cred->sgid, fc->group_id) &&
+ gid_eq(cred->gid, fc->group_id))
+ return 1;
+
+ return 0;
+}
+
+static int fuse_access(struct inode *inode, int mask)
+{
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ FUSE_ARGS(args);
+ struct fuse_access_in inarg;
+ int err;
+
+ BUG_ON(mask & MAY_NOT_BLOCK);
+
+ if (fc->no_access)
+ return 0;
+
+ memset(&inarg, 0, sizeof(inarg));
+ inarg.mask = mask & (MAY_READ | MAY_WRITE | MAY_EXEC);
+ args.in.h.opcode = FUSE_ACCESS;
+ args.in.h.nodeid = get_node_id(inode);
+ args.in.numargs = 1;
+ args.in.args[0].size = sizeof(inarg);
+ args.in.args[0].value = &inarg;
+ err = fuse_simple_request(fc, &args);
+ if (err == -ENOSYS) {
+ fc->no_access = 1;
+ err = 0;
+ }
+ return err;
+}
+
+static int fuse_perm_getattr(struct inode *inode, int mask)
+{
+ if (mask & MAY_NOT_BLOCK)
+ return -ECHILD;
+
+ forget_all_cached_acls(inode);
+ return fuse_do_getattr(inode, NULL, NULL);
+}
+
+/*
+ * Check permission. The two basic access models of FUSE are:
+ *
+ * 1) Local access checking ('default_permissions' mount option) based
+ * on file mode. This is the plain old disk filesystem permission
+ * modell.
+ *
+ * 2) "Remote" access checking, where server is responsible for
+ * checking permission in each inode operation. An exception to this
+ * is if ->permission() was invoked from sys_access() in which case an
+ * access request is sent. Execute permission is still checked
+ * locally based on file mode.
+ */
+static int fuse_permission(struct inode *inode, int mask)
+{
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ bool refreshed = false;
+ int err = 0;
+
+ if (!fuse_allow_current_process(fc))
+ return -EACCES;
+
+ /*
+ * If attributes are needed, refresh them before proceeding
+ */
+ if (fc->default_permissions ||
+ ((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) {
+ struct fuse_inode *fi = get_fuse_inode(inode);
+
+ if (time_before64(fi->i_time, get_jiffies_64())) {
+ refreshed = true;
+
+ err = fuse_perm_getattr(inode, mask);
+ if (err)
+ return err;
+ }
+ }
+
+ if (fc->default_permissions) {
+ err = generic_permission(inode, mask);
+
+ /* If permission is denied, try to refresh file
+ attributes. This is also needed, because the root
+ node will at first have no permissions */
+ if (err == -EACCES && !refreshed) {
+ err = fuse_perm_getattr(inode, mask);
+ if (!err)
+ err = generic_permission(inode, mask);
+ }
+
+ /* Note: the opposite of the above test does not
+ exist. So if permissions are revoked this won't be
+ noticed immediately, only after the attribute
+ timeout has expired */
+ } else if (mask & (MAY_ACCESS | MAY_CHDIR)) {
+ err = fuse_access(inode, mask);
+ } else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) {
+ if (!(inode->i_mode & S_IXUGO)) {
+ if (refreshed)
+ return -EACCES;
+
+ err = fuse_perm_getattr(inode, mask);
+ if (!err && !(inode->i_mode & S_IXUGO))
+ return -EACCES;
+ }
+ }
+ return err;
+}
+
+static int parse_dirfile(char *buf, size_t nbytes, struct file *file,
+ struct dir_context *ctx)
+{
+ while (nbytes >= FUSE_NAME_OFFSET) {
+ struct fuse_dirent *dirent = (struct fuse_dirent *) buf;
+ size_t reclen = FUSE_DIRENT_SIZE(dirent);
+ if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
+ return -EIO;
+ if (reclen > nbytes)
+ break;
+ if (memchr(dirent->name, '/', dirent->namelen) != NULL)
+ return -EIO;
+
+ if (!dir_emit(ctx, dirent->name, dirent->namelen,
+ dirent->ino, dirent->type))
+ break;
+
+ buf += reclen;
+ nbytes -= reclen;
+ ctx->pos = dirent->off;
+ }
+
+ return 0;
+}
+
+static int fuse_direntplus_link(struct file *file,
+ struct fuse_direntplus *direntplus,
+ u64 attr_version)
+{
+ struct fuse_entry_out *o = &direntplus->entry_out;
+ struct fuse_dirent *dirent = &direntplus->dirent;
+ struct dentry *parent = file->f_path.dentry;
+ struct qstr name = QSTR_INIT(dirent->name, dirent->namelen);
+ struct dentry *dentry;
+ struct dentry *alias;
+ struct inode *dir = d_inode(parent);
+ struct fuse_conn *fc;
+ struct inode *inode;
+ DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+
+ if (!o->nodeid) {
+ /*
+ * Unlike in the case of fuse_lookup, zero nodeid does not mean
+ * ENOENT. Instead, it only means the userspace filesystem did
+ * not want to return attributes/handle for this entry.
+ *
+ * So do nothing.
+ */
+ return 0;
+ }
+
+ if (name.name[0] == '.') {
+ /*
+ * We could potentially refresh the attributes of the directory
+ * and its parent?
+ */
+ if (name.len == 1)
+ return 0;
+ if (name.name[1] == '.' && name.len == 2)
+ return 0;
+ }
+
+ if (invalid_nodeid(o->nodeid))
+ return -EIO;
+ if (fuse_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 (is_bad_inode(inode)) {
+ dput(dentry);
+ return -EIO;
+ }
+
+ fi = get_fuse_inode(inode);
+ spin_lock(&fc->lock);
+ fi->nlookup++;
+ spin_unlock(&fc->lock);
+
+ forget_all_cached_acls(inode);
+ fuse_change_attributes(inode, &o->attr,
+ entry_attr_timeout(o),
+ attr_version);
+ /*
+ * The other branch comes via fuse_iget()
+ * which bumps nlookup inside
+ */
+ } else {
+ inode = fuse_iget(dir->i_sb, o->nodeid, o->generation,
+ &o->attr, entry_attr_timeout(o),
+ attr_version);
+ if (!inode)
+ inode = ERR_PTR(-ENOMEM);
+
+ alias = d_splice_alias(inode, dentry);
+ d_lookup_done(dentry);
+ if (alias) {
+ dput(dentry);
+ dentry = alias;
+ }
+ if (IS_ERR(dentry))
+ return PTR_ERR(dentry);
+ }
+ if (fc->readdirplus_auto)
+ set_bit(FUSE_I_INIT_RDPLUS, &get_fuse_inode(inode)->state);
+ fuse_change_entry_timeout(dentry, o);
+
+ dput(dentry);
+ return 0;
+}
+
+static int parse_dirplusfile(char *buf, size_t nbytes, struct file *file,
+ struct dir_context *ctx, u64 attr_version)
+{
+ struct fuse_direntplus *direntplus;
+ struct fuse_dirent *dirent;
+ size_t reclen;
+ int over = 0;
+ int ret;
+
+ while (nbytes >= FUSE_NAME_OFFSET_DIRENTPLUS) {
+ direntplus = (struct fuse_direntplus *) buf;
+ dirent = &direntplus->dirent;
+ reclen = FUSE_DIRENTPLUS_SIZE(direntplus);
+
+ if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
+ return -EIO;
+ if (reclen > nbytes)
+ break;
+ if (memchr(dirent->name, '/', dirent->namelen) != NULL)
+ return -EIO;
+
+ if (!over) {
+ /* We fill entries into dstbuf only as much as
+ it can hold. But we still continue iterating
+ over remaining entries to link them. If not,
+ we need to send a FORGET for each of those
+ which we did not link.
+ */
+ over = !dir_emit(ctx, dirent->name, dirent->namelen,
+ dirent->ino, dirent->type);
+ if (!over)
+ ctx->pos = dirent->off;
+ }
+
+ buf += reclen;
+ nbytes -= reclen;
+
+ ret = fuse_direntplus_link(file, direntplus, attr_version);
+ if (ret)
+ fuse_force_forget(file, direntplus->entry_out.nodeid);
+ }
+
+ return 0;
+}
+
+static int fuse_readdir(struct file *file, struct dir_context *ctx)
+{
+ int plus, err;
+ size_t nbytes;
+ struct page *page;
+ struct inode *inode = file_inode(file);
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ struct fuse_req *req;
+ u64 attr_version = 0;
+ bool locked;
+
+ if (is_bad_inode(inode))
+ return -EIO;
+
+ req = fuse_get_req(fc, 1);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
+
+ page = alloc_page(GFP_KERNEL);
+ if (!page) {
+ fuse_put_request(fc, req);
+ return -ENOMEM;
+ }
+
+ plus = fuse_use_readdirplus(inode, ctx);
+ req->out.argpages = 1;
+ req->num_pages = 1;
+ req->pages[0] = page;
+ req->page_descs[0].length = PAGE_SIZE;
+ if (plus) {
+ attr_version = fuse_get_attr_version(fc);
+ fuse_read_fill(req, file, ctx->pos, PAGE_SIZE,
+ FUSE_READDIRPLUS);
+ } else {
+ fuse_read_fill(req, file, ctx->pos, PAGE_SIZE,
+ FUSE_READDIR);
+ }
+ 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);
+
+ 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 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(&init_user_ns, iattr->ia_uid);
+ if (ivalid & ATTR_GID)
+ arg->valid |= FATTR_GID, arg->gid = from_kgid(&init_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(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) {
+ make_bad_inode(inode);
+ err = -EIO;
+ goto error;
+ }
+
+ spin_lock(&fc->lock);
+ /* the kernel maintains i_mtime locally */
+ if (trust_local_cmtime) {
+ if (attr->ia_valid & ATTR_MTIME)
+ inode->i_mtime = attr->ia_mtime;
+ if (attr->ia_valid & ATTR_CTIME)
+ inode->i_ctime = attr->ia_ctime;
+ /* FIXME: clear I_DIRTY_SYNC? */
+ }
+
+ fuse_change_attributes_common(inode, &outarg.attr,
+ attr_timeout(&outarg));
+ oldsize = inode->i_size;
+ /* see the comment in fuse_change_attributes() */
+ if (!is_wb || is_truncate || !S_ISREG(inode->i_mode))
+ i_size_write(inode, outarg.attr.size);
+
+ if (is_truncate) {
+ /* NOTE: this may release/reacquire fc->lock */
+ __fuse_release_nowrite(inode);
+ }
+ spin_unlock(&fc->lock);
+
+ /*
+ * Only call invalidate_inode_pages2() after removing
+ * FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock.
+ */
+ if ((is_truncate || !is_wb) &&
+ S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) {
+ truncate_pagecache(inode, outarg.attr.size);
+ invalidate_inode_pages2(inode->i_mapping);
+ }
+
+ clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
+ return 0;
+
+error:
+ if (is_truncate)
+ fuse_release_nowrite(inode);
+
+ clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
+ return err;
+}
+
+static int fuse_setattr(struct dentry *entry, struct iattr *attr)
+{
+ struct inode *inode = d_inode(entry);
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ struct file *file = (attr->ia_valid & ATTR_FILE) ? attr->ia_file : NULL;
+ int ret;
+
+ if (!fuse_allow_current_process(get_fuse_conn(inode)))
+ return -EACCES;
+
+ if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID)) {
+ attr->ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID |
+ ATTR_MODE);
+
+ /*
+ * The only sane way to reliably kill suid/sgid is to do it in
+ * the userspace filesystem
+ *
+ * This should be done on write(), truncate() and chown().
+ */
+ if (!fc->handle_killpriv) {
+ /*
+ * ia_mode calculation may have used stale i_mode.
+ * Refresh and recalculate.
+ */
+ ret = fuse_do_getattr(inode, NULL, file);
+ if (ret)
+ return ret;
+
+ attr->ia_mode = inode->i_mode;
+ if (inode->i_mode & S_ISUID) {
+ attr->ia_valid |= ATTR_MODE;
+ attr->ia_mode &= ~S_ISUID;
+ }
+ if ((inode->i_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
+ attr->ia_valid |= ATTR_MODE;
+ attr->ia_mode &= ~S_ISGID;
+ }
+ }
+ }
+ if (!attr->ia_valid)
+ return 0;
+
+ ret = fuse_do_setattr(entry, attr, file);
+ if (!ret) {
+ /*
+ * If filesystem supports acls it may have updated acl xattrs in
+ * the filesystem, so forget cached acls for the inode.
+ */
+ if (fc->posix_acl)
+ forget_all_cached_acls(inode);
+
+ /* Directory mode changed, may need to revalidate access */
+ if (d_is_dir(entry) && (attr->ia_valid & ATTR_MODE))
+ fuse_invalidate_entry_cache(entry);
+ }
+ return ret;
+}
+
+static int fuse_getattr(const struct path *path, struct kstat *stat,
+ u32 request_mask, unsigned int flags)
+{
+ struct inode *inode = d_inode(path->dentry);
+ struct fuse_conn *fc = get_fuse_conn(inode);
+
+ if (!fuse_allow_current_process(fc))
+ return -EACCES;
+
+ return fuse_update_get_attr(inode, NULL, stat);
+}
+
+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;
+}