// SPDX-License-Identifier: GPL-2.0
/*
 * (C) 2001 Clemson University and The University of Chicago
 *
 * See COPYING in top-level directory.
 */

/*
 *  Linux VFS namei operations.
 */

#include "protocol.h"
#include "orangefs-kernel.h"

/*
 * Get a newly allocated inode to go with a negative dentry.
 */
static int orangefs_create(struct mnt_idmap *idmap,
                        struct inode *dir,
                        struct dentry *dentry,
                        umode_t mode,
                        bool exclusive)
{
        struct orangefs_inode_s *parent = ORANGEFS_I(dir);
        struct orangefs_kernel_op_s *new_op;
        struct orangefs_object_kref ref;
        struct inode *inode;
        struct iattr iattr;
        int ret;

        gossip_debug(GOSSIP_NAME_DEBUG, "%s: %pd\n",
                     __func__,
                     dentry);

        new_op = op_alloc(ORANGEFS_VFS_OP_CREATE);
        if (!new_op)
                return -ENOMEM;

        new_op->upcall.req.create.parent_refn = parent->refn;

        fill_default_sys_attrs(new_op->upcall.req.create.attributes, mode);

        strscpy(new_op->upcall.req.create.d_name, dentry->d_name.name);

        ret = service_operation(new_op, __func__, get_interruptible_flag(dir));

        gossip_debug(GOSSIP_NAME_DEBUG,
                     "%s: %pd: handle:%pU: fsid:%d: new_op:%p: ret:%d:\n",
                     __func__,
                     dentry,
                     &new_op->downcall.resp.create.refn.khandle,
                     new_op->downcall.resp.create.refn.fs_id,
                     new_op,
                     ret);

        if (ret < 0)
                goto out;

        ref = new_op->downcall.resp.create.refn;

        inode = orangefs_new_inode(dir->i_sb, dir, S_IFREG | mode, 0, &ref);
        if (IS_ERR(inode)) {
                gossip_err("%s: Failed to allocate inode for file :%pd:\n",
                           __func__,
                           dentry);
                ret = PTR_ERR(inode);
                goto out;
        }

        gossip_debug(GOSSIP_NAME_DEBUG,
                     "%s: Assigned inode :%pU: for file :%pd:\n",
                     __func__,
                     get_khandle_from_ino(inode),
                     dentry);

        d_instantiate_new(dentry, inode);
        orangefs_set_timeout(dentry);

        gossip_debug(GOSSIP_NAME_DEBUG,
                     "%s: dentry instantiated for %pd\n",
                     __func__,
                     dentry);

        memset(&iattr, 0, sizeof iattr);
        iattr.ia_valid |= ATTR_MTIME | ATTR_CTIME;
        iattr.ia_mtime = iattr.ia_ctime = current_time(dir);
        __orangefs_setattr(dir, &iattr);
        ret = 0;
out:
        op_release(new_op);
        gossip_debug(GOSSIP_NAME_DEBUG,
                     "%s: %pd: returning %d\n",
                     __func__,
                     dentry,
                     ret);
        return ret;
}

/*
 * Attempt to resolve an object name (dentry->d_name), parent handle, and
 * fsid into a handle for the object.
 */
static struct dentry *orangefs_lookup(struct inode *dir, struct dentry *dentry,
                                   unsigned int flags)
{
        struct orangefs_inode_s *parent = ORANGEFS_I(dir);
        struct orangefs_kernel_op_s *new_op;
        struct inode *inode;
        int ret = -EINVAL;

        /*
         * in theory we could skip a lookup here (if the intent is to
         * create) in order to avoid a potentially failed lookup, but
         * leaving it in can skip a valid lookup and try to create a file
         * that already exists (e.g. the vfs already handles checking for
         * -EEXIST on O_EXCL opens, which is broken if we skip this lookup
         * in the create path)
         */
        gossip_debug(GOSSIP_NAME_DEBUG, "%s called on %pd\n",
                     __func__, dentry);

        if (dentry->d_name.len > (ORANGEFS_NAME_MAX - 1))
                return ERR_PTR(-ENAMETOOLONG);

        new_op = op_alloc(ORANGEFS_VFS_OP_LOOKUP);
        if (!new_op)
                return ERR_PTR(-ENOMEM);

        new_op->upcall.req.lookup.sym_follow = ORANGEFS_LOOKUP_LINK_NO_FOLLOW;

        gossip_debug(GOSSIP_NAME_DEBUG, "%s:%s:%d using parent %pU\n",
                     __FILE__,
                     __func__,
                     __LINE__,
                     &parent->refn.khandle);
        new_op->upcall.req.lookup.parent_refn = parent->refn;

        strscpy(new_op->upcall.req.lookup.d_name, dentry->d_name.name);

        gossip_debug(GOSSIP_NAME_DEBUG,
                     "%s: doing lookup on %s under %pU,%d\n",
                     __func__,
                     new_op->upcall.req.lookup.d_name,
                     &new_op->upcall.req.lookup.parent_refn.khandle,
                     new_op->upcall.req.lookup.parent_refn.fs_id);

        ret = service_operation(new_op, __func__, get_interruptible_flag(dir));

        gossip_debug(GOSSIP_NAME_DEBUG,
                     "Lookup Got %pU, fsid %d (ret=%d)\n",
                     &new_op->downcall.resp.lookup.refn.khandle,
                     new_op->downcall.resp.lookup.refn.fs_id,
                     ret);

        if (ret == 0) {
                orangefs_set_timeout(dentry);
                inode = orangefs_iget(dir->i_sb, &new_op->downcall.resp.lookup.refn);
        } else if (ret == -ENOENT) {
                inode = NULL;
        } else {
                /* must be a non-recoverable error */
                inode = ERR_PTR(ret);
        }

        op_release(new_op);
        return d_splice_alias(inode, dentry);
}

/* return 0 on success; non-zero otherwise */
static int orangefs_unlink(struct inode *dir, struct dentry *dentry)
{
        struct inode *inode = dentry->d_inode;
        struct orangefs_inode_s *parent = ORANGEFS_I(dir);
        struct orangefs_kernel_op_s *new_op;
        struct iattr iattr;
        int ret;

        gossip_debug(GOSSIP_NAME_DEBUG,
                     "%s: called on %pd\n"
                     "  (inode %pU): Parent is %pU | fs_id %d\n",
                     __func__,
                     dentry,
                     get_khandle_from_ino(inode),
                     &parent->refn.khandle,
                     parent->refn.fs_id);

        new_op = op_alloc(ORANGEFS_VFS_OP_REMOVE);
        if (!new_op)
                return -ENOMEM;

        new_op->upcall.req.remove.parent_refn = parent->refn;
        strscpy(new_op->upcall.req.remove.d_name, dentry->d_name.name);

        ret = service_operation(new_op, "orangefs_unlink",
                                get_interruptible_flag(inode));

        gossip_debug(GOSSIP_NAME_DEBUG,
                     "%s: service_operation returned:%d:\n",
                     __func__,
                     ret);

        op_release(new_op);

        if (!ret) {
                drop_nlink(inode);

                memset(&iattr, 0, sizeof iattr);
                iattr.ia_valid |= ATTR_MTIME | ATTR_CTIME;
                iattr.ia_mtime = iattr.ia_ctime = current_time(dir);
                __orangefs_setattr(dir, &iattr);
        }
        return ret;
}

static int orangefs_symlink(struct mnt_idmap *idmap,
                         struct inode *dir,
                         struct dentry *dentry,
                         const char *symname)
{
        struct orangefs_inode_s *parent = ORANGEFS_I(dir);
        struct orangefs_kernel_op_s *new_op;
        struct orangefs_object_kref ref;
        struct inode *inode;
        struct iattr iattr;
        int mode = 0755;
        int ret;

        gossip_debug(GOSSIP_NAME_DEBUG, "%s: called\n", __func__);

        if (!symname)
                return -EINVAL;

        if (strlen(symname)+1 > ORANGEFS_NAME_MAX)
                return -ENAMETOOLONG;

        new_op = op_alloc(ORANGEFS_VFS_OP_SYMLINK);
        if (!new_op)
                return -ENOMEM;

        new_op->upcall.req.sym.parent_refn = parent->refn;

        fill_default_sys_attrs(new_op->upcall.req.sym.attributes, mode);

        strscpy(new_op->upcall.req.sym.entry_name, dentry->d_name.name);
        strscpy(new_op->upcall.req.sym.target, symname);

        ret = service_operation(new_op, __func__, get_interruptible_flag(dir));

        gossip_debug(GOSSIP_NAME_DEBUG,
                     "Symlink Got ORANGEFS handle %pU on fsid %d (ret=%d)\n",
                     &new_op->downcall.resp.sym.refn.khandle,
                     new_op->downcall.resp.sym.refn.fs_id, ret);

        if (ret < 0) {
                gossip_debug(GOSSIP_NAME_DEBUG,
                            "%s: failed with error code %d\n",
                            __func__, ret);
                goto out;
        }

        ref = new_op->downcall.resp.sym.refn;

        inode = orangefs_new_inode(dir->i_sb, dir, S_IFLNK | mode, 0, &ref);
        if (IS_ERR(inode)) {
                gossip_err
                    ("*** Failed to allocate orangefs symlink inode\n");
                ret = PTR_ERR(inode);
                goto out;
        }
        /*
         * This is necessary because orangefs_inode_getattr will not
         * re-read symlink size as it is impossible for it to change.
         * Invalidating the cache does not help.  orangefs_new_inode
         * does not set the correct size (it does not know symname).
         */
        inode->i_size = strlen(symname);

        gossip_debug(GOSSIP_NAME_DEBUG,
                     "Assigned symlink inode new number of %pU\n",
                     get_khandle_from_ino(inode));

        d_instantiate_new(dentry, inode);
        orangefs_set_timeout(dentry);

        gossip_debug(GOSSIP_NAME_DEBUG,
                     "Inode (Symlink) %pU -> %pd\n",
                     get_khandle_from_ino(inode),
                     dentry);

        memset(&iattr, 0, sizeof iattr);
        iattr.ia_valid |= ATTR_MTIME | ATTR_CTIME;
        iattr.ia_mtime = iattr.ia_ctime = current_time(dir);
        __orangefs_setattr(dir, &iattr);
        ret = 0;
out:
        op_release(new_op);
        return ret;
}

static struct dentry *orangefs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
                                     struct dentry *dentry, umode_t mode)
{
        struct orangefs_inode_s *parent = ORANGEFS_I(dir);
        struct orangefs_kernel_op_s *new_op;
        struct orangefs_object_kref ref;
        struct inode *inode;
        struct iattr iattr;
        int ret;

        new_op = op_alloc(ORANGEFS_VFS_OP_MKDIR);
        if (!new_op)
                return ERR_PTR(-ENOMEM);

        new_op->upcall.req.mkdir.parent_refn = parent->refn;

        fill_default_sys_attrs(new_op->upcall.req.mkdir.attributes, mode);

        strscpy(new_op->upcall.req.mkdir.d_name, dentry->d_name.name);

        ret = service_operation(new_op, __func__, get_interruptible_flag(dir));

        gossip_debug(GOSSIP_NAME_DEBUG,
                     "Mkdir Got ORANGEFS handle %pU on fsid %d\n",
                     &new_op->downcall.resp.mkdir.refn.khandle,
                     new_op->downcall.resp.mkdir.refn.fs_id);

        if (ret < 0) {
                gossip_debug(GOSSIP_NAME_DEBUG,
                             "%s: failed with error code %d\n",
                             __func__, ret);
                goto out;
        }

        ref = new_op->downcall.resp.mkdir.refn;

        inode = orangefs_new_inode(dir->i_sb, dir, S_IFDIR | mode, 0, &ref);
        if (IS_ERR(inode)) {
                gossip_err("*** Failed to allocate orangefs dir inode\n");
                ret = PTR_ERR(inode);
                goto out;
        }

        gossip_debug(GOSSIP_NAME_DEBUG,
                     "Assigned dir inode new number of %pU\n",
                     get_khandle_from_ino(inode));

        d_instantiate_new(dentry, inode);
        orangefs_set_timeout(dentry);

        gossip_debug(GOSSIP_NAME_DEBUG,
                     "Inode (Directory) %pU -> %pd\n",
                     get_khandle_from_ino(inode),
                     dentry);

        /*
         * NOTE: we have no good way to keep nlink consistent for directories
         * across clients; keep constant at 1.
         */
        memset(&iattr, 0, sizeof iattr);
        iattr.ia_valid |= ATTR_MTIME | ATTR_CTIME;
        iattr.ia_mtime = iattr.ia_ctime = current_time(dir);
        __orangefs_setattr(dir, &iattr);
out:
        op_release(new_op);
        return ERR_PTR(ret);
}

static int orangefs_rename(struct mnt_idmap *idmap,
                        struct inode *old_dir,
                        struct dentry *old_dentry,
                        struct inode *new_dir,
                        struct dentry *new_dentry,
                        unsigned int flags)
{
        struct orangefs_kernel_op_s *new_op;
        struct iattr iattr;
        int ret;

        if (flags)
                return -EINVAL;

        gossip_debug(GOSSIP_NAME_DEBUG,
                     "orangefs_rename: called (%pd2 => %pd2) ct=%d\n",
                     old_dentry, new_dentry, d_count(new_dentry));

        memset(&iattr, 0, sizeof iattr);
        iattr.ia_valid |= ATTR_MTIME | ATTR_CTIME;
        iattr.ia_mtime = iattr.ia_ctime = current_time(new_dir);
        __orangefs_setattr(new_dir, &iattr);

        new_op = op_alloc(ORANGEFS_VFS_OP_RENAME);
        if (!new_op)
                return -EINVAL;

        new_op->upcall.req.rename.old_parent_refn = ORANGEFS_I(old_dir)->refn;
        new_op->upcall.req.rename.new_parent_refn = ORANGEFS_I(new_dir)->refn;

        strscpy(new_op->upcall.req.rename.d_old_name, old_dentry->d_name.name);
        strscpy(new_op->upcall.req.rename.d_new_name, new_dentry->d_name.name);

        ret = service_operation(new_op,
                                "orangefs_rename",
                                get_interruptible_flag(old_dentry->d_inode));

        gossip_debug(GOSSIP_NAME_DEBUG,
                     "orangefs_rename: got downcall status %d\n",
                     ret);

        if (new_dentry->d_inode)
                inode_set_ctime_current(d_inode(new_dentry));

        op_release(new_op);
        return ret;
}

/* ORANGEFS implementation of VFS inode operations for directories */
const struct inode_operations orangefs_dir_inode_operations = {
        .lookup = orangefs_lookup,
        .get_inode_acl = orangefs_get_acl,
        .set_acl = orangefs_set_acl,
        .create = orangefs_create,
        .unlink = orangefs_unlink,
        .symlink = orangefs_symlink,
        .mkdir = orangefs_mkdir,
        .rmdir = orangefs_unlink,
        .rename = orangefs_rename,
        .setattr = orangefs_setattr,
        .getattr = orangefs_getattr,
        .listxattr = orangefs_listxattr,
        .permission = orangefs_permission,
        .update_time = orangefs_update_time,
};