Function dfs_dentry_lookup

components/dfs/dfs_v2/src/dfs_dentry.c:281–353

* @brief Look up a directory entry (dentry) in the filesystem * * @param[in] mnt Pointer to the mount point structure * @param[in] path Path string to look up * @param[in] flags Additional lookup flags (currently unused) * * @return struct dfs_dentry* Pointer to found/created dentry (with increased ref_count), or NULL if not found * * @note This function first searches for dentry in hash t

 *          - If vnode is successfully obtained, adds dentry to hash table
 */
struct dfs_dentry *dfs_dentry_lookup(struct dfs_mnt *mnt, const char *path, uint32_t flags)
{
    struct dfs_dentry *dentry;
    struct dfs_vnode *vnode = RT_NULL;
    int mntpoint_len = strlen(mnt->fullpath);

    if (rt_strncmp(mnt->fullpath, path, mntpoint_len) == 0)
    {
        path += mntpoint_len;
        if ((*path) == '\0')
        {
            /* root */
            path = "/";
        }
    }
    dfs_file_lock();
    dentry = _dentry_hash_lookup(mnt, path);
    if (!dentry)
    {
        if (mnt->fs_ops->lookup)
        {
            DLOG(activate, "dentry");
            /* not in hash table, create it */
            DLOG(msg, "dentry", "dentry", DLOG_MSG, "dfs_dentry_create_rela(mnt=%s, path=%s)", mnt->fullpath, path);
            dentry = dfs_dentry_create_rela(mnt, (char*)path);
            if (dentry)
            {
                DLOG(msg, "dentry", mnt->fs_ops->name, DLOG_MSG, "vnode=fs_ops->lookup(dentry)");

                if (dfs_is_mounted(mnt) == 0)
                {
                    vnode = mnt->fs_ops->lookup(dentry);
                }

                if (vnode)
                {
                    DLOG(msg, mnt->fs_ops->name, "dentry", DLOG_MSG_RET, "return vnode");
                    dentry->vnode = vnode; /* the refcount of created vnode is 1. no need to reference */
                    dfs_file_lock();
                    rt_list_insert_after(&hash_head.head[_dentry_hash(mnt, path)], &dentry->hashlist);
                    dentry->flags |= DENTRY_IS_ADDHASH;
                    dfs_file_unlock();

                    if (dentry->flags & (DENTRY_IS_ALLOCED | DENTRY_IS_ADDHASH)
                        && !(dentry->flags & DENTRY_IS_OPENED))
                    {
                        rt_err_t ret = dfs_file_lock();
                        if (ret == RT_EOK)
                        {
                            dentry->flags |= DENTRY_IS_OPENED;
                            dfs_file_unlock();
                        }
                    }
                }
                else
                {
                    DLOG(msg, mnt->fs_ops->name, "dentry", DLOG_MSG_RET, "no dentry");