27 Aug, 2010

1 commit


30 Mar, 2010

1 commit

  • …it slab.h inclusion from percpu.h

    percpu.h is included by sched.h and module.h and thus ends up being
    included when building most .c files. percpu.h includes slab.h which
    in turn includes gfp.h making everything defined by the two files
    universally available and complicating inclusion dependencies.

    percpu.h -> slab.h dependency is about to be removed. Prepare for
    this change by updating users of gfp and slab facilities include those
    headers directly instead of assuming availability. As this conversion
    needs to touch large number of source files, the following script is
    used as the basis of conversion.

    http://userweb.kernel.org/~tj/misc/slabh-sweep.py

    The script does the followings.

    * Scan files for gfp and slab usages and update includes such that
    only the necessary includes are there. ie. if only gfp is used,
    gfp.h, if slab is used, slab.h.

    * When the script inserts a new include, it looks at the include
    blocks and try to put the new include such that its order conforms
    to its surrounding. It's put in the include block which contains
    core kernel includes, in the same order that the rest are ordered -
    alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
    doesn't seem to be any matching order.

    * If the script can't find a place to put a new include (mostly
    because the file doesn't have fitting include block), it prints out
    an error message indicating which .h file needs to be added to the
    file.

    The conversion was done in the following steps.

    1. The initial automatic conversion of all .c files updated slightly
    over 4000 files, deleting around 700 includes and adding ~480 gfp.h
    and ~3000 slab.h inclusions. The script emitted errors for ~400
    files.

    2. Each error was manually checked. Some didn't need the inclusion,
    some needed manual addition while adding it to implementation .h or
    embedding .c file was more appropriate for others. This step added
    inclusions to around 150 files.

    3. The script was run again and the output was compared to the edits
    from #2 to make sure no file was left behind.

    4. Several build tests were done and a couple of problems were fixed.
    e.g. lib/decompress_*.c used malloc/free() wrappers around slab
    APIs requiring slab.h to be added manually.

    5. The script was run on all .h files but without automatically
    editing them as sprinkling gfp.h and slab.h inclusions around .h
    files could easily lead to inclusion dependency hell. Most gfp.h
    inclusion directives were ignored as stuff from gfp.h was usually
    wildly available and often used in preprocessor macros. Each
    slab.h inclusion directive was examined and added manually as
    necessary.

    6. percpu.h was updated not to include slab.h.

    7. Build test were done on the following configurations and failures
    were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
    distributed build env didn't work with gcov compiles) and a few
    more options had to be turned off depending on archs to make things
    build (like ipr on powerpc/64 which failed due to missing writeq).

    * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
    * powerpc and powerpc64 SMP allmodconfig
    * sparc and sparc64 SMP allmodconfig
    * ia64 SMP allmodconfig
    * s390 SMP allmodconfig
    * alpha SMP allmodconfig
    * um on x86_64 SMP allmodconfig

    8. percpu.h modifications were reverted so that it could be applied as
    a separate patch and serve as bisection point.

    Given the fact that I had only a couple of failures from tests on step
    6, I'm fairly confident about the coverage of this conversion patch.
    If there is a breakage, it's likely to be something in one of the arch
    headers which should be easily discoverable easily on most builds of
    the specific arch.

    Signed-off-by: Tejun Heo <tj@kernel.org>
    Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

    Tejun Heo
     

23 Sep, 2009

1 commit

  • If the lower inode is read-only, don't attempt to open the lower file
    read/write and don't hand off the open request to the privileged
    eCryptfs kthread for opening it read/write. Instead, only try an
    unprivileged, read-only open of the file and give up if that fails.
    This patch fixes an oops when eCryptfs is mounted on top of a read-only
    mount.

    Acked-by: Serge Hallyn
    Cc: Eric Sandeen
    Cc: Dave Kleikamp
    Cc: ecryptfs-devel@lists.launchpad.net
    Cc: stable
    Signed-off-by: Tyler Hicks

    Tyler Hicks
     

14 Nov, 2008

1 commit

  • Pass credentials through dentry_open() so that the COW creds patch can have
    SELinux's flush_unauthorized_files() pass the appropriate creds back to itself
    when it opens its null chardev.

    The security_dentry_open() call also now takes a creds pointer, as does the
    dentry_open hook in struct security_operations.

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

    David Howells
     

25 Jul, 2008

1 commit

  • eCryptfs would really like to have read-write access to all files in the
    lower filesystem. Right now, the persistent lower file may be opened
    read-only if the attempt to open it read-write fails. One way to keep
    from having to do that is to have a privileged kthread that can open the
    lower persistent file on behalf of the user opening the eCryptfs file;
    this patch implements this functionality.

    This patch will properly allow a less-privileged user to open the eCryptfs
    file, followed by a more-privileged user opening the eCryptfs file, with
    the first user only being able to read and the second user being able to
    both read and write. eCryptfs currently does this wrong; it will wind up
    calling vfs_write() on a file that was opened read-only. This is fixed in
    this patch.

    Signed-off-by: Michael Halcrow
    Cc: Dave Kleikamp
    Cc: Serge Hallyn
    Cc: Eric Sandeen
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Michael Halcrow