Find-inum.stp

find-inum.stp

# cat find_same_inode.stap
#!/usr/bin/stap -g
# Copyright (c) 2014 Brad Hubbard <bhubbard@redhat.com>
 
%{
#include <linux/file.h>
%}
 
function find_same_inode:string (path:string) %{
        struct nameidata *nd;
        struct path* p;
        struct dentry* dent;
        struct inode* node;
        struct vfsmount* mnt;
        int err;
        char* path;
 
        nd = kmalloc(sizeof(*nd), GFP_KERNEL);
        err = path_lookup(STAP_ARG_path, 0, nd);
        if (err) {
                kfree(nd);
                nd = NULL;
                STAP_ERROR("FATAL ERROR: Path lookup failed");
                STAP_RETURN(1);
        } 
        p = &nd->path;
 
        path = kmalloc(PAGE_SIZE, GFP_KERNEL);
        tmp = kmalloc(PAGE_SIZE, GFP_KERNEL);
        path = d_path(p, path, PAGE_SIZE);
        strlcpy(STAP_RETVALUE, "Finding all paths for file: ", MAXSTRINGLEN);
        strlcpy(STAP_RETVALUE, path, MAXSTRINGLEN);
        strlcpy(STAP_RETVALUE, "\n\n", MAXSTRINGLEN);
        if(dent = kread(&p->dentry) && node = kread(&dent->d_inode) && mnt = kread(&p->mnt)) {
                spin_lock(&dcache_lock);
                list_for_each_entry(dent, &node->i_dentry, d_alias) {
                        struct path pth;
                        pth.dentry = dent;
                        pth.mnt = mnt;
                        spin_unlock(&dcache_lock);
                        path = d_path(&pth, path, PAGE_SIZE);
                        spin_lock(&dcache_lock);
                        strlcpy(STAP_RETVALUE, path, MAXSTRINGLEN);
                        strlcpy(STAP_RETVALUE, "\n\n", MAXSTRINGLEN);
                } 
                spin_unlock(&dcache_lock);
        }
 
        //snprintf(STAP_RETVALUE, MAXSTRINGLEN, "%s", path);
        CATCH_DEREF_FAULT();
        kfree(nd);
        kfree(path);
%}
 
probe begin {
         printf( "%s", find_same_inode(@1));
         exit();
}