1. 19 12月, 2012 2 次提交
  2. 08 11月, 2012 1 次提交
    • L
      eCryptfs: Avoid unnecessary disk read and data decryption during writing · e4bc6522
      Li Wang 提交于
      ecryptfs_write_begin grabs a page from page cache for writing.
      If the page contains invalid data, or data older than the
      counterpart on the disk, eCryptfs will read out the
      corresponing data from the disk into the page, decrypt them,
      then perform writing. However, for this page, if the length
      of the data to be written into is equal to page size,
      that means the whole page of data will be overwritten,
      in which case, it does not matter whatever the data were before,
      it is beneficial to perform writing directly rather than bothering
      to read and decrypt first.
      
      With this optimization, according to our test on a machine with
      Intel Core 2 Duo processor, iozone 'write' operation on an existing
      file with write size being multiple of page size will enjoy a steady
      3x speedup.
      Signed-off-by: NLi Wang <wangli@kylinos.com.cn>
      Signed-off-by: NYunchuan Wen <wenyunchuan@kylinos.com.cn>
      Signed-off-by: NTyler Hicks <tyhicks@canonical.com>
      e4bc6522
  3. 07 11月, 2012 7 次提交
  4. 03 11月, 2012 1 次提交
  5. 02 11月, 2012 1 次提交
  6. 01 11月, 2012 8 次提交
  7. 31 10月, 2012 1 次提交
  8. 29 10月, 2012 3 次提交
  9. 27 10月, 2012 1 次提交
    • L
      VFS: don't do protected {sym,hard}links by default · 561ec64a
      Linus Torvalds 提交于
      In commit 800179c9 ("This adds symlink and hardlink restrictions to
      the Linux VFS"), the new link protections were enabled by default, in
      the hope that no actual application would care, despite it being
      technically against legacy UNIX (and documented POSIX) behavior.
      
      However, it does turn out to break some applications.  It's rare, and
      it's unfortunate, but it's unacceptable to break existing systems, so
      we'll have to default to legacy behavior.
      
      In particular, it has broken the way AFD distributes files, see
      
        http://www.dwd.de/AFD/
      
      along with some legacy scripts.
      
      Distributions can end up setting this at initrd time or in system
      scripts: if you have security problems due to link attacks during your
      early boot sequence, you have bigger problems than some kernel sysctl
      setting. Do:
      
      	echo 1 > /proc/sys/fs/protected_symlinks
      	echo 1 > /proc/sys/fs/protected_hardlinks
      
      to re-enable the link protections.
      
      Alternatively, we may at some point introduce a kernel config option
      that sets these kinds of "more secure but not traditional" behavioural
      options automatically.
      Reported-by: NNick Bowler <nbowler@elliptictech.com>
      Reported-by: NHolger Kiehl <Holger.Kiehl@dwd.de>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
      Cc: Theodore Ts'o <tytso@mit.edu>
      Cc: stable@kernel.org # v3.6
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      561ec64a
  10. 26 10月, 2012 13 次提交
  11. 25 10月, 2012 1 次提交
  12. 24 10月, 2012 1 次提交