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  1. 19 4月, 2008 1 次提交
  3. 18 4月, 2008 5 次提交
  5. 07 2月, 2008 4 次提交
  7. 06 2月, 2008 1 次提交
    • C
      Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user · eebd2aa3
      由 Christoph Lameter 提交于 
      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: NChristoph 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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      eebd2aa3
  9. 17 10月, 2007 1 次提交
  11. 16 10月, 2007 4 次提交
  13. 15 10月, 2007 2 次提交
  15. 10 7月, 2007 1 次提交
  17. 19 6月, 2007 1 次提交
  19. 09 5月, 2007 1 次提交
  21. 08 5月, 2007 4 次提交
    • L
      [XFS] Fix race in xfs_write() b/w dmapi callout and direct I/O checks. · 71dfd5a3
      由 Lachlan McIlroy 提交于 
      In xfs_write() the iolock is dropped and reacquired in XFS_SEND_DATA()
which means that the file could change from not-cached to cached and we
need to redo the direct I/O checks. We should also redo the direct I/O
checks when the file size changes regardless if O_APPEND is set or not.

SGI-PV: 963483
SGI-Modid: xfs-linux-melb:xfs-kern:28440a
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NTim Shimmin <tes@sgi.com>
      71dfd5a3
    • L
      [XFS] Fix to prevent the notorious 'NULL files' problem after a crash. · ba87ea69
      由 Lachlan McIlroy 提交于 
      The problem that has been addressed is that of synchronising updates of
the file size with writes that extend a file. Without the fix the update
of a file's size, as a result of a write beyond eof, is independent of
when the cached data is flushed to disk. Often the file size update would
be written to the filesystem log before the data is flushed to disk. When
a system crashes between these two events and the filesystem log is
replayed on mount the file's size will be set but since the contents never
made it to disk the file is full of holes. If some of the cached data was
flushed to disk then it may just be a section of the file at the end that
has holes.

There are existing fixes to help alleviate this problem, particularly in
the case where a file has been truncated, that force cached data to be
flushed to disk when the file is closed. If the system crashes while the
file(s) are still open then this flushing will never occur.

The fix that we have implemented is to introduce a second file size,
called the in-memory file size, that represents the current file size as
viewed by the user. The existing file size, called the on-disk file size,
is the one that get's written to the filesystem log and we only update it
when it is safe to do so. When we write to a file beyond eof we only
update the in- memory file size in the write operation. Later when the I/O
operation, that flushes the cached data to disk completes, an I/O
completion routine will update the on-disk file size. The on-disk file
size will be updated to the maximum offset of the I/O or to the value of
the in-memory file size if the I/O includes eof.

SGI-PV: 958522
SGI-Modid: xfs-linux-melb:xfs-kern:28322a
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NTim Shimmin <tes@sgi.com>
      ba87ea69
    • L
      [XFS] Fix race condition in xfs_write(). · 2a329631
      由 Lachlan McIlroy 提交于 
      This change addresses a race in xfs_write() where, for direct I/O, the
flags need_i_mutex and need_flush are setup before the iolock is acquired.
The logic used to setup the flags may change between setting the flags and
acquiring the iolock resulting in these flags having incorrect values. For
example, if a file is not currently cached then need_i_mutex is set to
zero and then if the file is cached before the iolock is acquired we will
fail to do the flushinval before the direct write.

The flush (and also the call to xfs_zero_eof()) need to be done with the
iolock held exclusive so we need to acquire the iolock before checking for
cached data (or if the write begins after eof) to prevent this state from
changing. For direct I/O I've chosen to always acquire the iolock in
shared mode initially and if there is a need to promote it then drop it
and reacquire it.

There's also some other tidy-ups including removing the O_APPEND offset
adjustment since that work is done in generic_write_checks() (and we don't
use offset as an input parameter anywhere).

SGI-PV: 962170
SGI-Modid: xfs-linux-melb:xfs-kern:28319a
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NTim Shimmin <tes@sgi.com>
      2a329631
    • L
      [XFS] propogate return codes from flush routines · d3cf2094
      由 Lachlan McIlroy 提交于 
      This patch handles error return values in fs_flush_pages and
fs_flushinval_pages. It changes the prototype of fs_flushinval_pages so we
can propogate the errors and handle them at higher layers. I also modified
xfs_itruncate_start so that it could propogate the error further.

SGI-PV: 961990
SGI-Modid: xfs-linux-melb:xfs-kern:28231a
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NStewart Smith <stewart@flamingspork.com>
Signed-off-by: NTim Shimmin <tes@sgi.com>
      d3cf2094
  23. 10 2月, 2007 3 次提交
  25. 09 12月, 2006 1 次提交
  27. 01 10月, 2006 1 次提交
  29. 28 9月, 2006 1 次提交
  31. 07 9月, 2006 2 次提交
  33. 20 6月, 2006 1 次提交
  35. 19 6月, 2006 1 次提交
  37. 09 6月, 2006 5 次提交