1. 07 7月, 2011 38 次提交
  2. 21 6月, 2011 2 次提交
    • L
      Linux 3.0-rc4 · 56299378
      Linus Torvalds 提交于
      56299378
    • L
      vfs: i_state needs to be 'unsigned long' for now · 79568f5b
      Linus Torvalds 提交于
      Commit 13e12d14 ("vfs: reorganize 'struct inode' layout a bit")
      moved things around a bit changed i_state to be unsigned int instead of
      unsigned long.  That was to help structure layout for the 64-bit case,
      and shrink 'struct inode' a bit (admittedly that only happened when
      spinlock debugging was on and i_flags didn't pack with i_lock).
      
      However, Meelis Roos reports that this results in unaligned exceptions
      on sprc, and it turns out that the bit-locking primitives that we use
      for the I_NEW bit want to use the bitops.  Which want 'unsigned long',
      not 'unsigned int'.
      
      We really should fix the bit locking code to not have that kind of
      requirement, but that's a much bigger change.  So for now, revert that
      field back to 'unsigned long' (but keep the other re-ordering changes
      from the commit that caused this).
      
      Andi points out that we have played games with this in 'struct page', so
      it's solvable with other hacks too, but since right now the struct inode
      size advantage only happens with some rare config options, it's not
      worth fighting.
      
      It _would_ be worth fixing the bitlocking code, though.  Especially
      since there is no type safety in the bitlocking code (this never caused
      any warnings, and worked fine on x86-64, because the bitlocks take a
      'void *' and x86-64 doesn't care that deeply about alignment).  So it's
      currently a very easy problem to trigger by mistake and never notice.
      Reported-by: NMeelis Roos <mroos@linux.ee>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: David Miller <davem@davemloft.net>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      79568f5b