FIXES 72759
This patch removes use of the non-Public ILL structures by OpenAFS to
gather network interface information in order to make RX packet size
and server locality decisions.
FIXES 63763
probe for something else for 2.4 and older
====================
This delta was composed from multiple commits as part of the CVS->Git migration.
The checkin message with each commit was inconsistent.
The following are the additional commit messages.
====================
i'll spare you
FIXES 61906
2.6.21.1 introduces an additional .parent pointer in the middle of
the structure. As the OpenAFS code just initialises the structure
with a list, this causes it to assign the value intended
for .proc_handler to .parent
FIXES 61767
1 - task_struct loses thread_info, which is now accessible through the
task_thread_info() macro. A configure test is added to deal with this.
2 - the SLAB_CTOR_VERIFY flag is gone
don't enforce slowpass restriction on dynroot vcaches (and don't do unneeded work)
====================
This delta was composed from multiple commits as part of the CVS->Git migration.
The checkin message with each commit was inconsistent.
The following are the additional commit messages.
====================
oops, another change slipped in
Background: OpenAFS is vulnerable to crashing in the linux kernel symlink
code when running on kernel versions between 2.6.10 to 2.6.12. This also
includes all RHEL4 kernels, because RHEL4 includes the code from 2.6.10. The
problem is that the symlink text caching API, page_follow_link() et al, is
unsuitable for network filesystems where the page cache may be invalidated
in parallel with a path lookup.
This crash can be triggered easily by doing a bunch of path lookups
involving symlinks (e.g., stat() on various files pointed to through links),
while simultaneously running 'fs flushvol' on the volume containing the
symlinks.
The simplest way to fix this problem is to disable the use of symlink text
caching when the kernel does not provide a usable symlink API.
Based on Chris Wing's analysis which stated in part:
GFP_NOFS tells the allocator not to recurse back into the filesystem if it's
necessary to free up memory. However, vmalloc() does not have such an
option. Therefore, calling osi_Alloc() to request more than a page of
memory may end up recursing back into AFS to try to free unused inodes or
dentries.
In this case, what happened was that osi_Alloc() is called within an
AFS_GLOCK(); osi_Alloc() calls vmalloc() which tries to free dentry objects,
which then calls back into the AFS module. Unfortunately, AFS_GLOCK() is
already held and we deadlock.
