linux.git/fs/open.c, branch v2.6.32

fs: change sys_truncate length parameter type

2009-09-23T16:21:05+00:00

For this system call user space passes a signed long length parameter,
while the kernel side takes an unsigned long parameter and converts it
later to signed long again.

This has led to bugs in compat wrappers see e.g.  dd90bbd5 "powerpc: Add
compat_sys_truncate".  The s390 compat wrapper for this functions is
broken as well since it also performs zero extension instead of sign
extension for the length parameter.

In addition if hpa comes up with an automated way of generating
compat wrappers it would generate a wrong one here.

So change the length parameter from unsigned long to long.

Cc: "H. Peter Anvin" 
Cc: Al Viro 
Cc: Christoph Hellwig 
Signed-off-by: Heiko Carstens 
Signed-off-by: Linus Torvalds

CRED: Add some configurable debugging [try #6]

2009-09-02T11:29:01+00:00

Add a config option (CONFIG_DEBUG_CREDENTIALS) to turn on some debug checking
for credential management.  The additional code keeps track of the number of
pointers from task_structs to any given cred struct, and checks to see that
this number never exceeds the usage count of the cred struct (which includes
all references, not just those from task_structs).

Furthermore, if SELinux is enabled, the code also checks that the security
pointer in the cred struct is never seen to be invalid.

This attempts to catch the bug whereby inode_has_perm() faults in an nfsd
kernel thread on seeing cred->security be a NULL pointer (it appears that the
credential struct has been previously released):

	http://www.kerneloops.org/oops.php?number=252883

Signed-off-by: David Howells 
Signed-off-by: James Morris

vfs: allow file truncations when both suid and write permissions set

2009-08-21T04:25:48+00:00

When suid is set and the non-owner user has write permission, any writing
into this file should be allowed and suid should be removed after that.

However, current kernel only allows writing without truncations, when we
do truncations on that file, we get EPERM.  This is a bug.

Steps to reproduce this bug:

% ls -l rootdir/file1
-rwsrwsrwx 1 root root 3 Jun 25 15:42 rootdir/file1
% echo h > rootdir/file1
zsh: operation not permitted: rootdir/file1
% ls -l rootdir/file1
-rwsrwsrwx 1 root root 3 Jun 25 15:42 rootdir/file1
% echo h >> rootdir/file1
% ls -l rootdir/file1
-rwxrwxrwx 1 root root 5 Jun 25 16:34 rootdir/file1

Signed-off-by: WANG Cong 
Cc: Eric Sandeen 
Acked-by: Eric Paris 
Cc: Eugene Teo 
Cc: Al Viro 
Cc: OGAWA Hirofumi 
Cc: Christoph Hellwig 
Cc: Stephen Smalley 
Signed-off-by: Andrew Morton 
Signed-off-by: James Morris

fs: Add new pre-allocation ioctls to vfs for compatibility with legacy xfs ioctls

2009-06-24T12:15:27+00:00

This patch adds ioctls to vfs for compatibility with legacy XFS
pre-allocation ioctls (XFS_IOC_*RESVP*). The implementation
effectively invokes sys_fallocate for the new ioctls.
Also handles the compat_ioctl case.
Note: These legacy ioctls are also implemented by OCFS2.

[AV: folded fixes from hch]

Signed-off-by: Ankit Jain 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Al Viro

fs: introduce mnt_clone_write

2009-06-12T01:36:02+00:00

This patch speeds up lmbench lat_mmap test by about another 2% after the
first patch.

Before:
 avg = 462.286
 std = 5.46106

After:
 avg = 453.12
 std = 9.58257

(50 runs of each, stddev gives a reasonable confidence)

It does this by introducing mnt_clone_write, which avoids some heavyweight
operations of mnt_want_write if called on a vfsmount which we know already
has a write count; and mnt_want_write_file, which can call mnt_clone_write
if the file is open for write.

After these two patches, mnt_want_write and mnt_drop_write go from 7% on
the profile down to 1.3% (including mnt_clone_write).

[AV: mnt_want_write_file() should take file alone and derive mnt from it;
not only all callers have that form, but that's the only mnt about which
we know that it's already held for write if file is opened for write]

Cc: Dave Hansen 
Signed-off-by: Nick Piggin 
Signed-off-by: Al Viro

Switch open_exec() and sys_uselib() to do_open_filp()

2009-05-09T14:49:42+00:00

... and make path_lookup_open() static

Signed-off-by: Al Viro

Get rid of indirect include of fs_struct.h

2009-04-01T03:00:27+00:00

Don't pull it in sched.h; very few files actually need it and those
can include directly.  sched.h itself only needs forward declaration
of struct fs_struct;

Signed-off-by: Al Viro

vfs: Use lowercase names of quota functions

2009-03-26T01:18:35+00:00

Use lowercase names of quota functions instead of old uppercase ones.

Signed-off-by: Jan Kara 
CC: Alexander Viro

[CVE-2009-0029] System call wrappers part 30

2009-01-14T13:15:30+00:00

Signed-off-by: Heiko Carstens

[CVE-2009-0029] System call wrappers part 20

2009-01-14T13:15:26+00:00

Signed-off-by: Heiko Carstens