1. 20 7月, 2007 10 次提交
    • A
      freezer: run show_state() when freezing times out · 328616e3
      Andrew Morton 提交于
      To see which tasks are stuck where.
      
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Oleg Nesterov <oleg@tv-sign.ru>
      Cc: Alan Stern <stern@rowland.harvard.edu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      328616e3
    • M
      only allow nonlinear vmas for ram backed filesystems · 3ee6dafc
      Miklos Szeredi 提交于
      page_mkclean() doesn't re-protect ptes for non-linear mappings, so a later
      re-dirty through such a mapping will not generate a fault, PG_dirty will
      not reflect the dirty state and the dirty count will be skewed.  This
      implies that msync() is also currently broken for nonlinear mappings.
      
      The easiest solution is to emulate remap_file_pages on non-linear mappings
      with simple mmap() for non ram-backed filesystems.  Applications continue
      to work (albeit slower), as long as the number of remappings remain below
      the maximum vma count.
      
      However all currently known real uses of non-linear mappings are for ram
      backed filesystems, which this patch doesn't affect.
      Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
      Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: William Lee Irwin III <wli@holomorphy.com>
      Cc: Nick Piggin <nickpiggin@yahoo.com.au>
      Cc: Ingo Molnar <mingo@elte.hu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      3ee6dafc
    • M
      Remove alloc_zeroed_user_highpage() · bb2d5ce1
      Mel Gorman 提交于
      alloc_zeroed_user_highpage() has no in-tree users and it is not exported.
      As it is not exported, it can simply be removed.
      Signed-off-by: NMel Gorman <mel@csn.ul.ie>
      Acked-by: NAndy Whitcroft <apw@shadowen.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      bb2d5ce1
    • N
      mm: fix clear_page_dirty_for_io vs fault race · 79352894
      Nick Piggin 提交于
      Fix msync data loss and (less importantly) dirty page accounting
      inaccuracies due to the race remaining in clear_page_dirty_for_io().
      
      The deleted comment explains what the race was, and the added comments
      explain how it is fixed.
      Signed-off-by: NNick Piggin <npiggin@suse.de>
      Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
      Cc: Miklos Szeredi <miklos@szeredi.hu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      79352894
    • N
      mm: fault feedback #2 · 83c54070
      Nick Piggin 提交于
      This patch completes Linus's wish that the fault return codes be made into
      bit flags, which I agree makes everything nicer.  This requires requires
      all handle_mm_fault callers to be modified (possibly the modifications
      should go further and do things like fault accounting in handle_mm_fault --
      however that would be for another patch).
      
      [akpm@linux-foundation.org: fix alpha build]
      [akpm@linux-foundation.org: fix s390 build]
      [akpm@linux-foundation.org: fix sparc build]
      [akpm@linux-foundation.org: fix sparc64 build]
      [akpm@linux-foundation.org: fix ia64 build]
      Signed-off-by: NNick Piggin <npiggin@suse.de>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Cc: Ian Molton <spyro@f2s.com>
      Cc: Bryan Wu <bryan.wu@analog.com>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Cc: Hirokazu Takata <takata@linux-m32r.org>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Roman Zippel <zippel@linux-m68k.org>
      Cc: Greg Ungerer <gerg@uclinux.org>
      Cc: Matthew Wilcox <willy@debian.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
      Cc: Richard Curnow <rc@rc0.org.uk>
      Cc: William Lee Irwin III <wli@holomorphy.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
      Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
      Cc: Chris Zankel <chris@zankel.net>
      Acked-by: NKyle McMartin <kyle@mcmartin.ca>
      Acked-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
      Acked-by: NRalf Baechle <ralf@linux-mips.org>
      Acked-by: NAndi Kleen <ak@muc.de>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      [ Still apparently needs some ARM and PPC loving - Linus ]
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      83c54070
    • N
      mm: fault feedback #1 · d0217ac0
      Nick Piggin 提交于
      Change ->fault prototype.  We now return an int, which contains
      VM_FAULT_xxx code in the low byte, and FAULT_RET_xxx code in the next byte.
       FAULT_RET_ code tells the VM whether a page was found, whether it has been
      locked, and potentially other things.  This is not quite the way he wanted
      it yet, but that's changed in the next patch (which requires changes to
      arch code).
      
      This means we no longer set VM_CAN_INVALIDATE in the vma in order to say
      that a page is locked which requires filemap_nopage to go away (because we
      can no longer remain backward compatible without that flag), but we were
      going to do that anyway.
      
      struct fault_data is renamed to struct vm_fault as Linus asked. address
      is now a void __user * that we should firmly encourage drivers not to use
      without really good reason.
      
      The page is now returned via a page pointer in the vm_fault struct.
      Signed-off-by: NNick Piggin <npiggin@suse.de>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d0217ac0
    • M
      Document ->page_mkwrite() locking · ed2f2f9b
      Mark Fasheh 提交于
      There seems to be very little documentation about this callback in general.
      The locking in particular is a bit tricky, so it's worth having this in
      writing.
      Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>
      Cc: Nick Piggin <nickpiggin@yahoo.com.au>
      Cc: David Howells <dhowells@redhat.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ed2f2f9b
    • M
      ocfs2: release page lock before calling ->page_mkwrite · 69676147
      Mark Fasheh 提交于
      __do_fault() was calling ->page_mkwrite() with the page lock held, which
      violates the locking rules for that callback.  Release and retake the page
      lock around the callback to avoid deadlocking file systems which manually
      take it.
      Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>
      Cc: Nick Piggin <nickpiggin@yahoo.com.au>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      69676147
    • N
      mm: merge populate and nopage into fault (fixes nonlinear) · 54cb8821
      Nick Piggin 提交于
      Nonlinear mappings are (AFAIKS) simply a virtual memory concept that encodes
      the virtual address -> file offset differently from linear mappings.
      
      ->populate is a layering violation because the filesystem/pagecache code
      should need to know anything about the virtual memory mapping.  The hitch here
      is that the ->nopage handler didn't pass down enough information (ie.  pgoff).
       But it is more logical to pass pgoff rather than have the ->nopage function
      calculate it itself anyway (because that's a similar layering violation).
      
      Having the populate handler install the pte itself is likewise a nasty thing
      to be doing.
      
      This patch introduces a new fault handler that replaces ->nopage and
      ->populate and (later) ->nopfn.  Most of the old mechanism is still in place
      so there is a lot of duplication and nice cleanups that can be removed if
      everyone switches over.
      
      The rationale for doing this in the first place is that nonlinear mappings are
      subject to the pagefault vs invalidate/truncate race too, and it seemed stupid
      to duplicate the synchronisation logic rather than just consolidate the two.
      
      After this patch, MAP_NONBLOCK no longer sets up ptes for pages present in
      pagecache.  Seems like a fringe functionality anyway.
      
      NOPAGE_REFAULT is removed.  This should be implemented with ->fault, and no
      users have hit mainline yet.
      
      [akpm@linux-foundation.org: cleanup]
      [randy.dunlap@oracle.com: doc. fixes for readahead]
      [akpm@linux-foundation.org: build fix]
      Signed-off-by: NNick Piggin <npiggin@suse.de>
      Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
      Cc: Mark Fasheh <mark.fasheh@oracle.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      54cb8821
    • N
      mm: fix fault vs invalidate race for linear mappings · d00806b1
      Nick Piggin 提交于
      Fix the race between invalidate_inode_pages and do_no_page.
      
      Andrea Arcangeli identified a subtle race between invalidation of pages from
      pagecache with userspace mappings, and do_no_page.
      
      The issue is that invalidation has to shoot down all mappings to the page,
      before it can be discarded from the pagecache.  Between shooting down ptes to
      a particular page, and actually dropping the struct page from the pagecache,
      do_no_page from any process might fault on that page and establish a new
      mapping to the page just before it gets discarded from the pagecache.
      
      The most common case where such invalidation is used is in file truncation.
      This case was catered for by doing a sort of open-coded seqlock between the
      file's i_size, and its truncate_count.
      
      Truncation will decrease i_size, then increment truncate_count before
      unmapping userspace pages; do_no_page will read truncate_count, then find the
      page if it is within i_size, and then check truncate_count under the page
      table lock and back out and retry if it had subsequently been changed (ptl
      will serialise against unmapping, and ensure a potentially updated
      truncate_count is actually visible).
      
      Complexity and documentation issues aside, the locking protocol fails in the
      case where we would like to invalidate pagecache inside i_size.  do_no_page
      can come in anytime and filemap_nopage is not aware of the invalidation in
      progress (as it is when it is outside i_size).  The end result is that
      dangling (->mapping == NULL) pages that appear to be from a particular file
      may be mapped into userspace with nonsense data.  Valid mappings to the same
      place will see a different page.
      
      Andrea implemented two working fixes, one using a real seqlock, another using
      a page->flags bit.  He also proposed using the page lock in do_no_page, but
      that was initially considered too heavyweight.  However, it is not a global or
      per-file lock, and the page cacheline is modified in do_no_page to increment
      _count and _mapcount anyway, so a further modification should not be a large
      performance hit.  Scalability is not an issue.
      
      This patch implements this latter approach.  ->nopage implementations return
      with the page locked if it is possible for their underlying file to be
      invalidated (in that case, they must set a special vm_flags bit to indicate
      so).  do_no_page only unlocks the page after setting up the mapping
      completely.  invalidation is excluded because it holds the page lock during
      invalidation of each page (and ensures that the page is not mapped while
      holding the lock).
      
      This also allows significant simplifications in do_no_page, because we have
      the page locked in the right place in the pagecache from the start.
      Signed-off-by: NNick Piggin <npiggin@suse.de>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d00806b1
  2. 19 7月, 2007 30 次提交