Pushd and Propd issue in filesystem

Pushd and Propd issue in filesystem

[Saket Sinha]

I have to support pushd and popd from userspace in a filesystem that I have
designed.

In my filesystem driver, to implement it I have done the following

for popd - the driver implementation is
https://github.com/disdi/hepunion/blob/master/fs/hepunion/hepunion.h#L386
#define pop_root() \
current->fsuid = context->uid; \
current->fsgid = context->gid; \
recursive_mutex_unlock(&context->id_lock)


for pushd - the driver implementation is
https://github.com/disdi/hepunion/blob/master/fs/hepunion/hepunion.h#L393
#define push_root() \
recursive_mutex_lock(&context->id_lock); \
context->uid = current->fsuid; \
context->gid = current->fsgid; \
current->fsuid = 0; \
current->fsgid = 0


But this implementation is failing at run time.
This is the script with which I am testing this driver. All pushd and propd
are not working in this script.

After trying many other alternatives, I think overriding commits would be a
better choice. So then I would try overriding commits as the below link
http://lxr.free-electrons.com/source/fs/open.c?v=3.8#L312

Regards,
Saket Sinha
Can somebody help
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Pushd and Propd issue in filesystem

[Jonathan Neuschäfer]

On Tue, Aug 06, 2013 at 12:06:52PM +0530, Saket Sinha wrote:
> I have to support pushd and popd from userspace in a filesystem that I have
> designed.
> 
> In my filesystem driver, to implement it I have done the following
> 
> for popd - the driver implementation is
> https://github.com/disdi/hepunion/blob/master/fs/hepunion/hepunion.h#L386
> #define pop_root() \
> current->fsuid = context->uid; \
> current->fsgid = context->gid; \
> recursive_mutex_unlock(&context->id_lock)

What you're seeing there are *not* implementations of the pushd/popd
bash commands; these just use chdir, as you can find out by running bash
under strace.

> 
> for pushd - the driver implementation is
> https://github.com/disdi/hepunion/blob/master/fs/hepunion/hepunion.h#L393
> #define push_root() \
> recursive_mutex_lock(&context->id_lock); \
> context->uid = current->fsuid; \
> context->gid = current->fsgid; \
> current->fsuid = 0; \
> current->fsgid = 0
> 
> 
> But this implementation is failing at run time.

How is it failing?



Thanks,
Jonathan Neusch?fer