1. 05 Feb, 2008 1 commit
    • Christoph Lameter's avatar
      Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user · eebd2aa3
      Christoph Lameter authored
      Simplify page cache zeroing of segments of pages through 3 functions
      
      zero_user_segments(page, start1, end1, start2, end2)
      
              Zeros two segments of the page. It takes the position where to
              start and end the zeroing which avoids length calculations and
      	makes code clearer.
      
      zero_user_segment(page, start, end)
      
              Same for a single segment.
      
      zero_user(page, start, length)
      
              Length variant for the case where we know the length.
      
      We remove the zero_user_page macro. Issues:
      
      1. Its a macro. Inline functions are preferable.
      
      2. The KM_USER0 macro is only defined for HIGHMEM.
      
         Having to treat this special case everywhere makes the
         code needlessly complex. The parameter for zeroing is always
         KM_USER0 except in one single case that we open code.
      
      Avoiding KM_USER0 makes a lot of code not having to be dealing
      with the special casing for HIGHMEM anymore. Dealing with
      kmap is only necessary for HIGHMEM configurations. In those
      configurations we use KM_USER0 like we do for a series of other
      functions defined in highmem.h.
      
      Since KM_USER0 is depends on HIGHMEM the existing zero_user_page
      function could not be a macro. zero_user_* functions introduced
      here can be be inline because that constant is not used when these
      functions are called.
      
      Also extract the flushing of the caches to be outside of the kmap.
      
      [akpm@linux-foundation.org: fix nfs and ntfs build]
      [akpm@linux-foundation.org: fix ntfs build some more]
      Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
      Cc: Steven French <sfrench@us.ibm.com>
      Cc: Michael Halcrow <mhalcrow@us.ibm.com>
      Cc: <linux-ext4@vger.kernel.org>
      Cc: Steven Whitehouse <swhiteho@redhat.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: David Chinner <dgc@sgi.com>
      Cc: Michael Halcrow <mhalcrow@us.ibm.com>
      Cc: Steven French <sfrench@us.ibm.com>
      Cc: Steven Whitehouse <swhiteho@redhat.com>
      Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      eebd2aa3
  2. 17 Oct, 2007 1 commit
  3. 12 Oct, 2007 1 commit
    • Anton Altaparmakov's avatar
      NTFS: Fix a mount time deadlock. · bfab36e8
      Anton Altaparmakov authored
      Big thanks go to Mathias Kolehmainen for reporting the bug, providing
      debug output and testing the patches I sent him to get it working.
      
      The fix was to stop calling ntfs_attr_set() at mount time as that causes
      balance_dirty_pages_ratelimited() to be called which on systems with
      little memory actually tries to go and balance the dirty pages which tries
      to take the s_umount semaphore but because we are still in fill_super()
      across which the VFS holds s_umount for writing this results in a
      deadlock.
      
      We now do the dirty work by hand by submitting individual buffers.  This
      has the annoying "feature" that mounting can take a few seconds if the
      journal is large as we have clear it all.  One day someone should improve
      on this by deferring the journal clearing to a helper kernel thread so it
      can be done in the background but I don't have time for this at the moment
      and the current solution works fine so I am leaving it like this for now.
      Signed-off-by: default avatarAnton Altaparmakov <aia21@cantab.net>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      bfab36e8
  4. 10 Jul, 2007 1 commit
  5. 21 May, 2007 1 commit
    • Alexey Dobriyan's avatar
      Detach sched.h from mm.h · e8edc6e0
      Alexey Dobriyan authored
      First thing mm.h does is including sched.h solely for can_do_mlock() inline
      function which has "current" dereference inside. By dealing with can_do_mlock()
      mm.h can be detached from sched.h which is good. See below, why.
      
      This patch
      a) removes unconditional inclusion of sched.h from mm.h
      b) makes can_do_mlock() normal function in mm/mlock.c
      c) exports can_do_mlock() to not break compilation
      d) adds sched.h inclusions back to files that were getting it indirectly.
      e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were
         getting them indirectly
      
      Net result is:
      a) mm.h users would get less code to open, read, preprocess, parse, ... if
         they don't need sched.h
      b) sched.h stops being dependency for significant number of files:
         on x86_64 allmodconfig touching sched.h results in recompile of 4083 files,
         after patch it's only 3744 (-8.3%).
      
      Cross-compile tested on
      
      	all arm defconfigs, all mips defconfigs, all powerpc defconfigs,
      	alpha alpha-up
      	arm
      	i386 i386-up i386-defconfig i386-allnoconfig
      	ia64 ia64-up
      	m68k
      	mips
      	parisc parisc-up
      	powerpc powerpc-up
      	s390 s390-up
      	sparc sparc-up
      	sparc64 sparc64-up
      	um-x86_64
      	x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig
      
      as well as my two usual configs.
      Signed-off-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e8edc6e0
  6. 12 May, 2007 1 commit
  7. 08 May, 2007 1 commit
  8. 07 May, 2007 1 commit
  9. 12 Feb, 2007 1 commit
  10. 08 Dec, 2006 1 commit
  11. 01 Oct, 2006 4 commits
  12. 25 Jun, 2006 1 commit
    • NeilBrown's avatar
      [PATCH] Prepare for __copy_from_user_inatomic to not zero missed bytes · 01408c49
      NeilBrown authored
      The problem is that when we write to a file, the copy from userspace to
      pagecache is first done with preemption disabled, so if the source address is
      not immediately available the copy fails *and* *zeros* *the* *destination*.
      
      This is a problem because a concurrent read (which admittedly is an odd thing
      to do) might see zeros rather that was there before the write, or what was
      there after, or some mixture of the two (any of these being a reasonable thing
      to see).
      
      If the copy did fail, it will immediately be retried with preemption
      re-enabled so any transient problem with accessing the source won't cause an
      error.
      
      The first copying does not need to zero any uncopied bytes, and doing so
      causes the problem.  It uses copy_from_user_atomic rather than copy_from_user
      so the simple expedient is to change copy_from_user_atomic to *not* zero out
      bytes on failure.
      
      The first of these two patches prepares for the change by fixing two places
      which assume copy_from_user_atomic does zero the tail.  The two usages are
      very similar pieces of code which copy from a userspace iovec into one or more
      page-cache pages.  These are changed to remove the assumption.
      
      The second patch changes __copy_from_user_inatomic* to not zero the tail.
      Once these are accepted, I will look at similar patches of other architectures
      where this is important (ppc, mips and sparc being the ones I can find).
      
      This patch:
      
      There is a problem with __copy_from_user_inatomic zeroing the tail of the
      buffer in the case of an error.  As it is called in atomic context, the error
      may be transient, so it results in zeros being written where maybe they
      shouldn't be.
      
      In the usage in filemap, this opens a window for a well timed read to see data
      (zeros) which is not consistent with any ordering of reads and writes.
      
      Most cases where __copy_from_user_inatomic is called, a failure results in
      __copy_from_user being called immediately.  As long as the latter zeros the
      tail, the former doesn't need to.  However in *copy_from_user_iovec
      implementations (in both filemap and ntfs/file), it is assumed that
      copy_from_user_inatomic will zero the tail.
      
      This patch removes that assumption, so that after this patch it will
      be safe for copy_from_user_inatomic to not zero the tail.
      
      This patch also adds some commentary to filemap.h and asm-i386/uaccess.h.
      
      After this patch, all architectures that might disable preempt when
      kmap_atomic is called need to have their __copy_from_user_inatomic* "fixed".
      This includes
       - powerpc
       - i386
       - mips
       - sparc
      Signed-off-by: default avatarNeil Brown <neilb@suse.de>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Anton Altaparmakov <aia21@cantab.net>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: William Lee Irwin III <wli@holomorphy.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      01408c49
  13. 23 Jun, 2006 1 commit
  14. 22 Jun, 2006 1 commit
  15. 28 Mar, 2006 1 commit
  16. 23 Mar, 2006 1 commit
  17. 07 Mar, 2006 1 commit
  18. 24 Feb, 2006 1 commit
  19. 10 Jan, 2006 1 commit
  20. 09 Jan, 2006 1 commit
  21. 24 Nov, 2005 1 commit
  22. 01 Nov, 2005 1 commit
  23. 24 Oct, 2005 2 commits
  24. 19 Oct, 2005 2 commits
  25. 11 Oct, 2005 1 commit
    • Anton Altaparmakov's avatar
      NTFS: The big ntfs write(2) rewrite has arrived. We now implement our own · 98b27036
      Anton Altaparmakov authored
            file operations ->write(), ->aio_write(), and ->writev() for regular
            files.  This replaces the old use of generic_file_write(), et al and
            the address space operations ->prepare_write and ->commit_write.
            This means that both sparse and non-sparse (unencrypted and
            uncompressed) files can now be extended using the normal write(2)
            code path.  There are two limitations at present and these are that
            we never create sparse files and that we only have limited support
            for highly fragmented files, i.e. ones whose data attribute is split
            across multiple extents.   When such a case is encountered,
            EOPNOTSUPP is returned.
      Signed-off-by: default avatarAnton Altaparmakov <aia21@cantab.net>
      98b27036
  26. 08 Sep, 2005 1 commit
  27. 04 May, 2005 1 commit
  28. 16 Apr, 2005 1 commit
    • Linus Torvalds's avatar
      Linux-2.6.12-rc2 · 1da177e4
      Linus Torvalds authored
      Initial git repository build. I'm not bothering with the full history,
      even though we have it. We can create a separate "historical" git
      archive of that later if we want to, and in the meantime it's about
      3.2GB when imported into git - space that would just make the early
      git days unnecessarily complicated, when we don't have a lot of good
      infrastructure for it.
      
      Let it rip!
      1da177e4