f_mapping->host vs. f_path.dentry->d_inode

It appears that there are (at least) two ways to get the inode (if any) associated with an open file: f_mapping->host (pagecache?) and f_path.dentry->d_inode (dentry cache?). generic_file_llseek uses f_mapping->host; everything else in read_write.c uses f_path.dentry->d_inode. do_sendfile

f_mapping-host vs. f_path.dentry-d_inode

It appears that there are (at least) two ways to get the inode (if any) associated with an open file: f_mapping-host (pagecache?) and f_path.dentry-d_inode (dentry cache?). generic_file_llseek uses f_mapping-host; everything else in read_write.c uses f_path.dentry-d_inode. do_sendfile checks