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  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
  3. 08 Jan, 2008 1 commit
  5. 31 Dec, 2007 1 commit
  7. 20 Nov, 2007 1 commit
    • Jeff Layton's avatar
      [CIFS] Fix potential data corruption when writing out cached dirty pages · cea21805
      Jeff Layton authored 
      Fix RedHat bug 329431

The idea here is separate "conscious" from "unconscious" flushes.
Conscious flushes are those due to a fsync() or close(). Unconscious
ones are flushes that occur as a side effect of some other operation or
due to memory pressure.

Currently, when an error occurs during an unconscious flush (ENOSPC or
EIO), we toss out the page and don't preserve that error to report to
the user when a conscious flush occurs. If after the unconscious flush,
there are no more dirty pages for the inode, the conscious flush will
simply return success even though there were previous errors when writing
out pages. This can lead to data corruption.

The easiest way to reproduce this is to mount up a CIFS share that's
very close to being full or where the user is very close to quota. mv
a file to the share that's slightly larger than the quota allows. The
writes will all succeed (since they go to pagecache). The mv will do a
setattr to set the new file's attributes. This calls
filemap_write_and_wait,
which will return an error since all of the pages can't be written out.
Then later, when the flush and release ops occur, there are no more
dirty pages in pagecache for the file and those operations return 0. mv
then assumes that the file was written out correctly and deletes the
original.

CIFS already has a write_behind_rc variable where it stores the results
from earlier flushes, but that value is only reported in cifs_close.
Since the VFS ignores the return value from the release operation, this
isn't helpful. We should be reporting this error during the flush
operation.

This patch does the following:

1) changes cifs_fsync to use filemap_write_and_wait and cifs_flush and also
sync to check its return code. If it returns successful, they then check
the value of write_behind_rc to see if an earlier flush had reported any
errors. If so, they return that error and clear write_behind_rc.

2) sets write_behind_rc in a few other places where pages are written
out as a side effect of other operations and the code waits on them.

3) changes cifs_setattr to only call filemap_write_and_wait for
ATTR_SIZE changes.

4) makes cifs_writepages accurately distinguish between EIO and ENOSPC
errors when writing out pages.

Some simple testing indicates that the patch works as expected and that
it fixes the reproduceable known problem.
Acked-by: default avatarDave Kleikamp <shaggy@austin.rr.com>
Signed-off-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
      cea21805
  9. 30 Oct, 2007 1 commit
  11. 25 Oct, 2007 1 commit
  13. 19 Oct, 2007 1 commit
  15. 18 Oct, 2007 1 commit
  17. 14 Oct, 2007 1 commit
  19. 28 Sep, 2007 1 commit
  21. 16 Sep, 2007 2 commits
  23. 13 Sep, 2007 1 commit
  25. 30 Aug, 2007 1 commit
  27. 22 Aug, 2007 1 commit
  29. 18 Jul, 2007 1 commit
  31. 16 Jul, 2007 2 commits
  33. 14 Jul, 2007 1 commit
    • Steve French's avatar
      [CIFS] Add support for new POSIX unlink · 2d785a50
      Steve French authored 
      In the cleanup phase of the dbench test, we were noticing sharing
violation followed by failed directory removals when dbench
did not close the test files before the cleanup phase started.
Using the new POSIX unlink, which Samba has supported for a few
months, avoids this.
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
      2d785a50
  35. 12 Jul, 2007 1 commit
  37. 09 Jul, 2007 1 commit
  39. 08 Jun, 2007 1 commit
    • Steve French's avatar
      [CIFS] CIFS should honour umask · 3ce53fc4
      Steve French authored 
      This patch makes CIFS honour a process' umask like other filesystems.
Of course the server is still free to munge the permissions if it wants
to; but the client will send the "right" permissions to begin with.

A few caveats:

1) It only applies to filesystems that have CAP_UNIX (aka support unix
extensions)
2) It applies the correct mode to the follow up CIFSSMBUnixSetPerms()
after remote creation

When mode to CIFS/NTFS ACL mapping is complete we can do the
same thing for that case for servers which do not
support the Unix Extensions.
Signed-off-by: default avatarMatt Keenen <matt@opcode-solutions.com>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
      3ce53fc4
  41. 30 Apr, 2007 1 commit
    • Steve French's avatar
      [CIFS] UID/GID override on CIFS mounts to Samba · 4523cc30
      Steve French authored 
      When CIFS Unix Extensions are negotiated we get the Unix uid and gid
owners of the file from the server (on the Unix Query Path Info
levels), but if the server's uids don't match the client uid's users
were having to disable the Unix Extensions (which turned off features
they still wanted).   The changeset patch allows users to override uid
and/or gid for file/directory owner with a default uid and/or gid
specified at mount (as is often done when mounting from Linux cifs
client to Windows server).  This changeset also displays the uid
and gid used by default in /proc/mounts (if applicable).

Also cleans up code by adding some of the missing spaces after
"if" keywords per-kernel style guidelines (as suggested by Randy Dunlap
when he reviewed the patch).
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
      4523cc30
  43. 25 Apr, 2007 1 commit
  45. 23 Apr, 2007 1 commit
  47. 06 Apr, 2007 1 commit
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  51. 09 Mar, 2007 1 commit
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  55. 16 Feb, 2007 1 commit
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  59. 08 Feb, 2007 1 commit
  61. 16 Nov, 2006 1 commit
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  69. 01 Oct, 2006 2 commits