CODEWITHSUNDEEP
linuxlinux-kernel
Billy The Bob
Billy The Bob

Reputation: 321

Linux Kernel dentry and inode

Is it possible to construct absolute path from the given dentry and inode?

Thanks all

Upvotes: 4

Views: 4618

Answers (3)

weiweishuo
weiweishuo

Reputation: 927

yes, just one dentry is enough, back traversing through dentry->parent. take care when you meet a mountpoint, for linux support "one dentry mounts multiple devices" ... well, it's easy to code,just switch to vfsmnt->mnt_parent .

BTW: i was often confused why linux builds the mountpoint-linklist with a field "mnt_parent" rather than "mnt_child", when writing this answer, i seemed to guess out somthing.

Upvotes: 1

Karmastan
Karmastan

Reputation: 5696

Take a look at dentry_path(). It will fill a buffer with the path up to the mount's root. To keep going past there, you'll need iterate through your file's f_vfsmount and it's mnt_parents until you reach the real root of the file system.

Upvotes: 1

J-16 SDiZ
J-16 SDiZ

Reputation: 26910

If you have a struct path (or can construct one), look at how tomoyo do this: http://lxr.linux.no/linux+v2.6.37/security/tomoyo/realpath.c#L86

Upvotes: 1

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