linux-toradex.git/fs/anon_inodes.c, branch v2.6.32.45

headers: remove sched.h from poll.h

2009-10-04T22:05:10+00:00

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Linus Torvalds

anonfd: split interface into file creation and install

2009-09-23T14:39:29+00:00

Split the anonfd interface into a bare file pointer creation one, and a
file pointer creation plus install one.

There are cases, like the usage of eventfds inside other kernel
interfaces, where the file pointer created by anonfd needs to be used
inside the initialization of other structures.

As it is right now, as soon as anon_inode_getfd() returns, the kenrle can
race with userspace closing the newly installed file descriptor.

This patch, while keeping the old anon_inode_getfd(), introduces a new
anon_inode_getfile() (whose services are reused in anon_inode_getfd())
that allows to split the file creation phase and the fd install one.

Once all the kernel structures are initialized, the code can call the
proper fd_install().

Gregory manifested the need for something like this inside KVM.

Signed-off-by: Davide Libenzi 
Cc: Alexander Viro 
Cc: James Morris 
Cc: Peter Zijlstra 
Cc: Gregory Haskins 
Acked-by: Serge Hallyn 
Acked-by: Roland Dreier 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fs: Provide empty .set_page_dirty() aop for anon inodes

2009-06-18T12:46:10+00:00

.set_page_dirty() is one of those a_ops that defaults to the
buffer implementation when not set. Therefore provide a dummy
function to make it do nothing.

(Uncovered by perfcounters fd's which can now be writable-mmap-ed.)

Signed-off-by: Peter Zijlstra 
Cc: Al Viro 
Cc: Davide Libenzi 
LKML-Reference: 
Signed-off-by: Ingo Molnar

constify dentry_operations: rest

2009-03-27T18:44:03+00:00

Signed-off-by: Al Viro

anon_inodes: use fops->owner for module refcount

2008-12-31T14:55:44+00:00

There is an imbalance for anonymous inodes. If the fops->owner field is set,
the module reference count of owner is decreases on release.
("filp_close" --> "__fput" ---> "fops_put")

On the other hand, anon_inode_getfd does not increase the module reference
count of owner. This causes two problems:

- if owner is set, the module refcount goes negative
- if owner is not set, the module can be unloaded while code is running

This patch changes anon_inode_getfd to be symmetric regarding fops->owner
handling.

I have checked all existing users of anon_inode_getfd. Noone sets fops->owner,
thats why nobody has seen the module refcount negative. The refcounting was
tested with a patched and unpatched KVM module.(see patch 2/2) I also did an
epoll_open/close test.

Signed-off-by: Christian Borntraeger 
Reviewed-by: Davide Libenzi 
Signed-off-by: Avi Kivity

CRED: Wrap task credential accesses in the filesystem subsystem

2008-11-13T23:39:05+00:00

Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.

Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().

Change some task->e?[ug]id to task_e?[ug]id().  In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.

Signed-off-by: David Howells 
Reviewed-by: James Morris 
Acked-by: Serge Hallyn 
Cc: Al Viro 
Signed-off-by: James Morris

flag parameters: NONBLOCK in anon_inode_getfd

2008-07-24T17:47:28+00:00

Building on the previous change to anon_inode_getfd, this patch introduces
support for handling of O_NONBLOCK in addition to the already supported
O_CLOEXEC.  Following patches will take advantage of this support.  As can be
seen, the additional support for supporting this functionality is minimal.

Signed-off-by: Ulrich Drepper 
Acked-by: Davide Libenzi 
Cc: Michael Kerrisk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

flag parameters: anon_inode_getfd extension

2008-07-24T17:47:27+00:00

This patch just extends the anon_inode_getfd interface to take an additional
parameter with a flag value.  The flag value is passed on to
get_unused_fd_flags in anticipation for a use with the O_CLOEXEC flag.

No actual semantic changes here, the changed callers all pass 0 for now.

[akpm@linux-foundation.org: KVM fix]
Signed-off-by: Ulrich Drepper 
Acked-by: Davide Libenzi 
Cc: Michael Kerrisk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] sanitize anon_inode_getfd()

2008-05-01T17:08:50+00:00

a) none of the callers even looks at inode or file returned by anon_inode_getfd()
b) any caller that would try to look at those would be racy, since by the time
it returns we might have raced with close() from another thread and that
file would be pining for fjords.

Signed-off-by: Al Viro

[PATCH] fix up new filp allocators

2008-03-19T10:54:05+00:00

Some new uses of get_empty_filp() have crept in; switched
to alloc_file() to make sure that pieces of initialization
won't be missing.

We really need to kill get_empty_filp().

[AV] fixed dentry leak on failure exit in anon_inode_getfd()

Cc: Erez Zadok 
Cc: Trond Myklebust 
Cc: "J Bruce Fields" 
Acked-by: Al Viro 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Dave Hansen 
Signed-off-by: Al Viro