1. 05 Feb, 2008 9 commits
    • Hugh Dickins's avatar
      tmpfs: move swap swizzling into shmem · 73b1262f
      Hugh Dickins authored
      move_to_swap_cache and move_from_swap_cache functions (which swizzle a page
      between tmpfs page cache and swap cache, to avoid page copying) are only used
      by shmem.c; and our subsequent fix for unionfs needs different treatments in
      the two instances of move_from_swap_cache.  Move them from swap_state.c into
      their callsites shmem_writepage, shmem_unuse_inode and shmem_getpage, making
      add_to_swap_cache externally visible.
      
      shmem.c likes to say set_page_dirty where swap_state.c liked to say
      SetPageDirty: respect that diversity, which __set_page_dirty_no_writeback
      makes moot (and implies we should lose that "shift page from clean_pages to
      dirty_pages list" comment: it's on neither).
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      73b1262f
    • Michael Marineau's avatar
      tmpfs: fix mounts when size is less than the page size · 818db359
      Michael Marineau authored
      When tmpfs is mounted with a size less than one page, the number of blocks
      is set to 0 which makes the tmpfs mount unlimited.  This can lead to a
      quick and surprising death if someone typos a tmpfs mount command and
      writes too much.
      
      tmpfs can still be mounted as unlimited if size or nr_blocks is exactly 0,
      as Documentation/filesystems/tmpfs.txt says.
      
      Hugh: do this by rounding size up instead of down in all cases: which
      slightly expands other odd-sized tmpfs mounts, but in a consistent way.
      Signed-off-by: default avatarMichael Marineau <mike@marineau.org>
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      818db359
    • Pavel Emelyanov's avatar
      shmem: factor out sbi->free_inodes manipulations · 5b04c689
      Pavel Emelyanov authored
      The shmem_sb_info structure has a number of free_inodes. This
      value is altered in appropriate places under spinlock and with
      the sbi->max_inodes != 0 check.
      
      Consolidate these manipulations into two helpers.
      
      This is minus 42 bytes of shmem.o and minus 4 :) lines of code.
      
      [akpm@linux-foundation.org: fix error return values]
      Signed-off-by: default avatarPavel Emelyanov <xemul@openvz.org>
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5b04c689
    • Hugh Dickins's avatar
      shmem_file_write is redundant · 5402b976
      Hugh Dickins authored
      With the old aops, writing to a tmpfs file had to use its own special method:
      the generic method would pass in a fresh page to prepare_write when the right
      page was there in swapcache - which was inefficient to handle, even once we'd
      concocted the code to handle it.
      
      With the new aops, the generic method uses shmem_write_end, which lets
      shmem_getpage find the right page: so now abandon shmem_file_write in favour
      of the generic method.  Yes, that does do several things that tmpfs hasn't
      really needed (notably balance_dirty_pages_ratelimited, which ramfs also
      calls); but more use of common code is preferable.
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Cc: Nick Piggin <nickpiggin@yahoo.com.au>
      Acked-by: default avatarRik van Riel <riel@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5402b976
    • Hugh Dickins's avatar
      shmem_getpage return page locked · d3602444
      Hugh Dickins authored
      In the new aops, write_begin is supposed to return the page locked: though
      I've seen no ill effects, that's been overlooked in the case of
      shmem_write_begin, and should be fixed.  Then shmem_write_end must unlock the
      page: do so _after_ updating i_size, as we found to be important in other
      filesystems (though since shmem pages don't go the usual writeback route, they
      never suffered from that corruption).
      
      For shmem_write_begin to return the page locked, we need shmem_getpage to
      return the page locked in SGP_WRITE case as well as SGP_CACHE case: let's
      simplify the interface and return it locked even when SGP_READ.
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Acked-by: default avatarRik van Riel <riel@redhat.com>
      Cc: Nick Piggin <nickpiggin@yahoo.com.au>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d3602444
    • Hugh Dickins's avatar
      shmem: SGP_QUICK and SGP_FAULT redundant · 27d54b39
      Hugh Dickins authored
      Remove SGP_QUICK from the sgp_type enum: it was for shmem_populate and has no
      users now.  Remove SGP_FAULT from the enum: SGP_CACHE does just as well (and
      shmem_getpage is about to return with page always locked).
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Acked-by: default avatarRik van Riel <riel@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      27d54b39
    • Hugh Dickins's avatar
      swapin needs gfp_mask for loop on tmpfs · 02098fea
      Hugh Dickins authored
      Building in a filesystem on a loop device on a tmpfs file can hang when
      swapping, the loop thread caught in that infamous throttle_vm_writeout.
      
      In theory this is a long standing problem, which I've either never seen in
      practice, or long ago suppressed the recollection, after discounting my load
      and my tmpfs size as unrealistically high.  But now, with the new aops, it has
      become easy to hang on one machine.
      
      Loop used to grab_cache_page before the old prepare_write to tmpfs, which
      seems to have been enough to free up some memory for any swapin needed; but
      the new write_begin lets tmpfs find or allocate the page (much nicer, since
      grab_cache_page missed tmpfs pages in swapcache).
      
      When allocating a fresh page, tmpfs respects loop's mapping_gfp_mask, which
      has __GFP_IO|__GFP_FS stripped off, and throttle_vm_writeout is designed to
      break out when __GFP_IO or GFP_FS is unset; but when tmfps swaps in,
      read_swap_cache_async allocates with GFP_HIGHUSER_MOVABLE regardless of the
      mapping_gfp_mask - hence the hang.
      
      So, pass gfp_mask down the line from shmem_getpage to shmem_swapin to
      swapin_readahead to read_swap_cache_async to add_to_swap_cache.
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Acked-by: default avatarRik van Riel <riel@redhat.com>
      Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      02098fea
    • Hugh Dickins's avatar
      swapin_readahead: move and rearrange args · 46017e95
      Hugh Dickins authored
      swapin_readahead has never sat well in mm/memory.c: move it to mm/swap_state.c
      beside its kindred read_swap_cache_async.  Why were its args in a different
      order?  rearrange them.  And since it was always followed by a
      read_swap_cache_async of the target page, fold that in and return struct
      page*.  Then CONFIG_SWAP=n no longer needs valid_swaphandles and
      read_swap_cache_async stubs.
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Acked-by: default avatarRik van Riel <riel@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      46017e95
    • Hugh Dickins's avatar
      swapin_readahead: excise NUMA bogosity · c4cc6d07
      Hugh Dickins authored
      For three years swapin_readahead has been cluttered with fanciful CONFIG_NUMA
      code, advancing addr, and stepping on to the next vma at the boundary, to line
      up the mempolicy for each page allocation.
      
      It _might_ be a good idea to allocate swap more according to vma layout; but
      the fact is, that's not how we do it at all, 2.6 even less than 2.4: swap is
      allocated as needed for pages as they sink to the bottom of the inactive LRUs.
       Sometimes that may match vma layout, but not so often that it's worth going
      to these misleading vma->vm_next lengths: rip all that out.
      
      Originally I intended to retain the incrementation of addr, but correct its
      initial value: valid_swaphandles generally supplies an offset below the target
      addr (this is readaround rather than readahead), but addr has not been
      adjusted accordingly, so in the interleave case it has usually been allocating
      the target page from the "wrong" node (though that may not matter very much).
      
      But look at the equivalent shmem_swapin code: either by oversight or by
      design, though it has all the apparatus for choosing a new mempolicy per page,
      it uses the same idx throughout, choosing the same mempolicy and interleave
      node for each page of the cluster.
      
      Which is actually a much better strategy: each node has its own LRUs and its
      own kswapd, so if you're betting on any particular relationship between swap
      and node, the best bet is that nearby swap entries belong to pages from the
      same node - even when the mempolicy of the target page is to interleave.  And
      examining a map of nodes corresponding to swap entries on a numa=fake system
      bears this out.  (We could later tweak swap allocation to make it even more
      likely, but this patch is merely about removing cruft.)
      
      So, neither adjust nor increment addr in swapin_readahead, and then
      shmem_swapin can use it too; the pseudo-vma to pass policy need only be set up
      once per cluster, and so few fields of pvma are used, let's skip the memset -
      from shmem_alloc_page also.
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Acked-by: default avatarRik van Riel <riel@redhat.com>
      Cc: Andi Kleen <ak@suse.de>
      Cc: Christoph Lameter <clameter@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c4cc6d07
  2. 28 Nov, 2007 1 commit
  3. 30 Oct, 2007 1 commit
    • Hugh Dickins's avatar
      fix tmpfs BUG and AOP_WRITEPAGE_ACTIVATE · 487e9bf2
      Hugh Dickins authored
      It's possible to provoke unionfs (not yet in mainline, though in mm and
      some distros) to hit shmem_writepage's BUG_ON(page_mapped(page)).  I expect
      it's possible to provoke the 2.6.23 ecryptfs in the same way (but the
      2.6.24 ecryptfs no longer calls lower level's ->writepage).
      
      This came to light with the recent find that AOP_WRITEPAGE_ACTIVATE could
      leak from tmpfs via write_cache_pages and unionfs to userspace.  There's
      already a fix (e4230030 - writeback: don't
      propagate AOP_WRITEPAGE_ACTIVATE) in the tree for that, and it's okay so
      far as it goes; but insufficient because it doesn't address the underlying
      issue, that shmem_writepage expects to be called only by vmscan (relying on
      backing_dev_info capabilities to prevent the normal writeback path from
      ever approaching it).
      
      That's an increasingly fragile assumption, and ramdisk_writepage (the other
      source of AOP_WRITEPAGE_ACTIVATEs) is already careful to check
      wbc->for_reclaim before returning it.  Make the same check in
      shmem_writepage, thereby sidestepping the page_mapped BUG also.
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Cc: Erez Zadok <ezk@cs.sunysb.edu>
      Cc: <stable@kernel.org>
      Reviewed-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      487e9bf2
  4. 22 Oct, 2007 2 commits
  5. 17 Oct, 2007 4 commits
  6. 16 Oct, 2007 5 commits
  7. 19 Jul, 2007 5 commits
    • Paul Mundt's avatar
      mm: Remove slab destructors from kmem_cache_create(). · 20c2df83
      Paul Mundt authored
      Slab destructors were no longer supported after Christoph's
      c59def9f change. They've been
      BUGs for both slab and slub, and slob never supported them
      either.
      
      This rips out support for the dtor pointer from kmem_cache_create()
      completely and fixes up every single callsite in the kernel (there were
      about 224, not including the slab allocator definitions themselves,
      or the documentation references).
      Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
      20c2df83
    • Nick Piggin's avatar
      mm: fault feedback #2 · 83c54070
      Nick Piggin authored
      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: default avatarNick 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: default avatarKyle McMartin <kyle@mcmartin.ca>
      Acked-by: default avatarHaavard Skinnemoen <hskinnemoen@atmel.com>
      Acked-by: default avatarRalf Baechle <ralf@linux-mips.org>
      Acked-by: default avatarAndi Kleen <ak@muc.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      [ Still apparently needs some ARM and PPC loving - Linus ]
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      83c54070
    • Nick Piggin's avatar
      mm: fault feedback #1 · d0217ac0
      Nick Piggin authored
      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: default avatarNick Piggin <npiggin@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d0217ac0
    • Nick Piggin's avatar
      mm: merge populate and nopage into fault (fixes nonlinear) · 54cb8821
      Nick Piggin authored
      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: default avatarNick Piggin <npiggin@suse.de>
      Signed-off-by: default avatarRandy Dunlap <randy.dunlap@oracle.com>
      Cc: Mark Fasheh <mark.fasheh@oracle.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      54cb8821
    • Nick Piggin's avatar
      mm: fix fault vs invalidate race for linear mappings · d00806b1
      Nick Piggin authored
      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: default avatarNick Piggin <npiggin@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d00806b1
  8. 17 Jul, 2007 2 commits
    • Christoph Hellwig's avatar
      knfsd: exportfs: add exportfs.h header · a5694255
      Christoph Hellwig authored
      currently the export_operation structure and helpers related to it are in
      fs.h.  fs.h is already far too large and there are very few places needing the
      export bits, so split them off into a separate header.
      
      [akpm@linux-foundation.org: fix cifs build]
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarNeil Brown <neilb@suse.de>
      Cc: Steven French <sfrench@us.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a5694255
    • Mel Gorman's avatar
      Add __GFP_MOVABLE for callers to flag allocations from high memory that may be migrated · 769848c0
      Mel Gorman authored
      It is often known at allocation time whether a page may be migrated or not.
      This patch adds a flag called __GFP_MOVABLE and a new mask called
      GFP_HIGH_MOVABLE.  Allocations using the __GFP_MOVABLE can be either migrated
      using the page migration mechanism or reclaimed by syncing with backing
      storage and discarding.
      
      An API function very similar to alloc_zeroed_user_highpage() is added for
      __GFP_MOVABLE allocations called alloc_zeroed_user_highpage_movable().  The
      flags used by alloc_zeroed_user_highpage() are not changed because it would
      change the semantics of an existing API.  After this patch is applied there
      are no in-kernel users of alloc_zeroed_user_highpage() so it probably should
      be marked deprecated if this patch is merged.
      
      Note that this patch includes a minor cleanup to the use of __GFP_ZERO in
      shmem.c to keep all flag modifications to inode->mapping in the
      shmem_dir_alloc() helper function.  This clean-up suggestion is courtesy of
      Hugh Dickens.
      
      Additional credit goes to Christoph Lameter and Linus Torvalds for shaping the
      concept.  Credit to Hugh Dickens for catching issues with shmem swap vector
      and ramfs allocations.
      
      [akpm@linux-foundation.org: build fix]
      [hugh@veritas.com: __GFP_ZERO cleanup]
      Signed-off-by: default avatarMel Gorman <mel@csn.ul.ie>
      Cc: Andy Whitcroft <apw@shadowen.org>
      Cc: Christoph Lameter <clameter@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      769848c0
  9. 10 Jul, 2007 1 commit
  10. 08 Jun, 2007 1 commit
  11. 17 May, 2007 1 commit
    • Christoph Lameter's avatar
      Remove SLAB_CTOR_CONSTRUCTOR · a35afb83
      Christoph Lameter authored
      SLAB_CTOR_CONSTRUCTOR is always specified. No point in checking it.
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Jens Axboe <jens.axboe@oracle.com>
      Cc: Steven French <sfrench@us.ibm.com>
      Cc: Michael Halcrow <mhalcrow@us.ibm.com>
      Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
      Cc: Miklos Szeredi <miklos@szeredi.hu>
      Cc: Steven Whitehouse <swhiteho@redhat.com>
      Cc: Roman Zippel <zippel@linux-m68k.org>
      Cc: David Woodhouse <dwmw2@infradead.org>
      Cc: Dave Kleikamp <shaggy@austin.ibm.com>
      Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
      Cc: "J. Bruce Fields" <bfields@fieldses.org>
      Cc: Anton Altaparmakov <aia21@cantab.net>
      Cc: Mark Fasheh <mark.fasheh@oracle.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Jan Kara <jack@ucw.cz>
      Cc: David Chinner <dgc@sgi.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a35afb83
  12. 07 May, 2007 1 commit
    • Christoph Lameter's avatar
      slab allocators: Remove SLAB_DEBUG_INITIAL flag · 50953fe9
      Christoph Lameter authored
      I have never seen a use of SLAB_DEBUG_INITIAL.  It is only supported by
      SLAB.
      
      I think its purpose was to have a callback after an object has been freed
      to verify that the state is the constructor state again?  The callback is
      performed before each freeing of an object.
      
      I would think that it is much easier to check the object state manually
      before the free.  That also places the check near the code object
      manipulation of the object.
      
      Also the SLAB_DEBUG_INITIAL callback is only performed if the kernel was
      compiled with SLAB debugging on.  If there would be code in a constructor
      handling SLAB_DEBUG_INITIAL then it would have to be conditional on
      SLAB_DEBUG otherwise it would just be dead code.  But there is no such code
      in the kernel.  I think SLUB_DEBUG_INITIAL is too problematic to make real
      use of, difficult to understand and there are easier ways to accomplish the
      same effect (i.e.  add debug code before kfree).
      
      There is a related flag SLAB_CTOR_VERIFY that is frequently checked to be
      clear in fs inode caches.  Remove the pointless checks (they would even be
      pointless without removeal of SLAB_DEBUG_INITIAL) from the fs constructors.
      
      This is the last slab flag that SLUB did not support.  Remove the check for
      unimplemented flags from SLUB.
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      50953fe9
  13. 29 Mar, 2007 3 commits
    • Hugh Dickins's avatar
      [PATCH] holepunch: fix disconnected pages after second truncate · 16a10019
      Hugh Dickins authored
      shmem_truncate_range has its own truncate_inode_pages_range, to free any pages
      racily instantiated while it was in progress: a SHMEM_PAGEIN flag is set when
      this might have happened.  But holepunching gets no chance to clear that flag
      at the start of vmtruncate_range, so it's always set (unless a truncate came
      just before), so holepunch almost always does this second
      truncate_inode_pages_range.
      
      shmem holepunch has unlikely swap<->file races hereabouts whatever we do
      (without a fuller rework than is fit for this release): I was going to skip
      the second truncate in the punch_hole case, but Miklos points out that would
      make holepunch correctness more vulnerable to swapoff.  So keep the second
      truncate, but follow it by an unmap_mapping_range to eliminate the
      disconnected pages (freed from pagecache while still mapped in userspace) that
      it might have left behind.
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Cc: Miklos Szeredi <mszeredi@suse.cz>
      Cc: Badari Pulavarty <pbadari@us.ibm.com>
      Cc: Nick Piggin <npiggin@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      16a10019
    • Hugh Dickins's avatar
      [PATCH] holepunch: fix shmem_truncate_range punch locking · 1ae70006
      Hugh Dickins authored
      Miklos Szeredi observes that during truncation of shmem page directories,
      info->lock is released to improve latency (after lowering i_size and
      next_index to exclude races); but this is quite wrong for holepunching, which
      receives no such protection from i_size or next_index, and is left vulnerable
      to races with shmem_unuse, shmem_getpage and shmem_writepage.
      
      Hold info->lock throughout when holepunching?  No, any user could prevent
      rescheduling for far too long.  Instead take info->lock just when needed: in
      shmem_free_swp when removing the swap entries, and whenever removing a
      directory page from the level above.  But so long as we remove before
      scanning, we can safely skip taking the lock at the lower levels, except at
      misaligned start and end of the hole.
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Cc: Miklos Szeredi <mszeredi@suse.cz>
      Cc: Badari Pulavarty <pbadari@us.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1ae70006
    • Hugh Dickins's avatar
      [PATCH] holepunch: fix shmem_truncate_range punching too far · a2646d1e
      Hugh Dickins authored
      Miklos Szeredi observes BUG_ON(!entry) in shmem_writepage() triggered in rare
      circumstances, because shmem_truncate_range() erroneously removes partially
      truncated directory pages at the end of the range: later reclaim on pages
      pointing to these removed directories triggers the BUG.  Indeed, and it can
      also cause data loss beyond the hole.
      
      Fix this as in the patch proposed by Miklos, but distinguish between "limit"
      (how far we need to search: ignore truncation's next_index optimization in the
      holepunch case - if there are races it's more consistent to act on the whole
      range specified) and "upper_limit" (how far we can free directory pages:
      generally we must be careful to keep partially punched pages, but can relax at
      end of file - i_size being held stable by i_mutex).
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Cc: Miklos Szeredi <mszeredi@suse.cs>
      Cc: Badari Pulavarty <pbadari@us.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a2646d1e
  14. 05 Mar, 2007 1 commit
  15. 01 Mar, 2007 1 commit
  16. 12 Feb, 2007 1 commit
  17. 11 Feb, 2007 1 commit
    • Ken Chen's avatar
      [PATCH] simplify shmem_aops.set_page_dirty() method · 76719325
      Ken Chen authored
      shmem backed file does not have page writeback, nor it participates in
      backing device's dirty or writeback accounting.  So using generic
      __set_page_dirty_nobuffers() for its .set_page_dirty aops method is a bit
      overkill.  It unnecessarily prolongs shm unmap latency.
      
      For example, on a densely populated large shm segment (sevearl GBs), the
      unmapping operation becomes painfully long.  Because at unmap, kernel
      transfers dirty bit in PTE into page struct and to the radix tree tag.  The
      operation of tagging the radix tree is particularly expensive because it
      has to traverse the tree from the root to the leaf node on every dirty
      page.  What's bothering is that radix tree tag is used for page write back.
       However, shmem is memory backed and there is no page write back for such
      file system.  And in the end, we spend all that time tagging radix tree and
      none of that fancy tagging will be used.  So let's simplify it by introduce
      a new aops __set_page_dirty_no_writeback and this will speed up shm unmap.
      Signed-off-by: default avatarKen Chen <kenchen@google.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Hugh Dickins <hugh@veritas.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      76719325