Commit Graph

98 Commits

Author SHA1 Message Date
NeilBrown a32ea1e1f9 Fix read/truncate race
do_generic_mapping_read currently samples the i_size at the start and doesn't
do so again unless it needs to call ->readpage to load a page.  After
->readpage it has to re-sample i_size as a truncate may have caused that page
to be filled with zeros, and the read() call should not see these.

However there are other activities that might cause ->readpage to be called on
a page between the time that do_generic_mapping_read samples i_size and when
it finds that it has an uptodate page.  These include at least read-ahead and
possibly another thread performing a read.

So do_generic_mapping_read must sample i_size *after* it has an uptodate page.
 Thus the current sampling at the start and after a read can be replaced with
a sampling before the copy-out.

The same change applied to __generic_file_splice_read.

Note that this fixes any race with truncate_complete_page, but does not fix a
possible race with truncate_partial_page.  If a partial truncate happens after
do_generic_mapping_read samples i_size and before the copy_out, the nuls that
truncate_partial_page place in the page could be copied out incorrectly.

I think the best fix for that is to *not* zero out parts of the page in
truncate_partial_page, but rather to zero out the tail of a page when
increasing i_size.

Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:22:59 -07:00
Micah Cowan 17973f5af7 Only send SIGXFSZ when exceeding rlimits.
Some users have been having problems with utilities like cp or dd dumping
core when they try to copy a file that's too large for the destination
filesystem (typically, > 4gb).  Apparently, some defunct standards required
SIGXFSZ to be sent in such circumstances, but SUS only requires/allows it
for when a written file exceeds the process's resource limits.  I'd like to
limit SIGXFSZs to the bare minimum required by SUS.

Patch sent per http://lkml.org/lkml/2007/4/10/302

Signed-off-by: Micah Cowan <micahcowan@ubuntu.com>
Acked-by: Alan Cox <alan@redhat.com>
Cc: <reiserfs-dev@namesys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:43 -07:00
akpm@linux-foundation.org c44939ecb6 NeilBrown <neilb@suse.de>
The do_loop_readv_writev implementation of readv breaks out of the loop as
soon as a single read request didn't fill it's buffer:

		if (nr != len)
			break;

The generic_file_aio_read version doesn't.  So if it hits EOF before the end
of the list of buffers, it will try again on the next buffer.  If the file was
extended in the mean time, this will produce a bad result.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:37 -07:00
Nick Piggin 45426812d6 mm: debug check for the fault vs invalidate race
Add a bugcheck for Andrea's pagefault vs invalidate race.  This is triggerable
for both linear and nonlinear pages with a userspace test harness (using
direct IO and truncate, respectively).

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:35 -07:00
Jens Axboe 0452a4e5d0 sendfile: kill generic_file_sendfile()
It's no longer used.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-07-10 08:04:14 +02:00
Peter Zijlstra 4e99325b46 mm: double mark_page_accessed() in read_cache_page_async()
Fix a post-2.6.21 regression.

read_cache_page_async() has two invocations of mark_page_accessed() which will
launch pages right onto the active list.

Remove the first one, keeping the latter one.  This avoids marking unwanted
pages active (in the retry loop).

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-08 10:13:21 -07:00
Christoph Lameter 43c0f3d25c Fix: find_or_create_page skips cpuset memory spreading.
We call alloc_page where we should be calling __page_cache_alloc.

__page_cache_alloc performs cpuset memory spreading.  alloc_page does not.
There is no reason that pages allocated via find_or_create should be
exempt.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-16 21:19:15 -07:00
David Howells c855ff3718 Fix a bad error case handling in read_cache_page_async()
Commit 6fe6900e1e introduced a nasty bug
in read_cache_page_async().

It added a "mark_page_accessed(page)" at the final return path in
read_cache_page_async().  But in error cases, 'page' holds the error
code, and you can't mark it accessed.

[ and Glauber de Oliveira Costa points out that we can use a return
  instead of adding more goto's ]

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 13:04:03 -07:00
David Howells ef71c15c46 AFS: export a couple of core functions for AFS write support
Export a couple of core functions for AFS write support to use:

	find_get_pages_contig()
	find_get_pages_tag()

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:50 -07:00
Mark Fasheh ef51c97623 Remove do_sync_file_range()
Remove do_sync_file_range() and convert callers to just use
do_sync_mapping_range().

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:15:04 -07:00
Dmitriy Monakhov 0ceb331433 mm: move common segment checks to separate helper function
[akpm@linux-foundation.org: cleanup]
Signed-off-by: Monakhov Dmitriy <dmonakhov@openvz.org>
Cc: Christoph Hellwig <hch@lst.de>
Acked-by: Anton Altaparmakov <aia21@cam.ac.uk>
Acked-by: David Chinner <dgc@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:14:57 -07:00
Jan Kara 6ce745ed39 readahead: code cleanup
Rename file_ra_state.prev_page to prev_index and file_ra_state.offset to
prev_offset.  Also update of prev_index in do_generic_mapping_read() is now
moved close to the update of prev_offset.

[wfg@mail.ustc.edu.cn: fix it]
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: WU Fengguang <wfg@mail.ustc.edu.cn>
Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:52 -07:00
Jan Kara ec0f163722 readahead: improve heuristic detecting sequential reads
Introduce ra.offset and store in it an offset where the previous read
ended.  This way we can detect whether reads are really sequential (and
thus we should not mark the page as accessed repeatedly) or whether they
are random and just happen to be in the same page (and the page should
really be marked accessed again).

Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: WU Fengguang <wfg@mail.ustc.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:52 -07:00
Nick Piggin a8127717cb mm: simplify filemap_nopage
Identical block is duplicated twice: contrary to the comment, we have been
re-reading the page *twice* in filemap_nopage rather than once.

If any retry logic or anything is needed, it belongs in lower levels anyway.
Only retry once.  Linus agrees.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:52 -07:00
Nick Piggin 6fe6900e1e mm: make read_cache_page synchronous
Ensure pages are uptodate after returning from read_cache_page, which allows
us to cut out most of the filesystem-internal PageUptodate calls.

I didn't have a great look down the call chains, but this appears to fixes 7
possible use-before uptodate in hfs, 2 in hfsplus, 1 in jfs, a few in
ecryptfs, 1 in jffs2, and a possible cleared data overwritten with readpage in
block2mtd.  All depending on whether the filler is async and/or can return
with a !uptodate page.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:51 -07:00
Zach Brown 65b8291c40 [PATCH] dio: invalidate clean pages before dio write
This patch fixes a user-triggerable oops that was reported by Leonid
Ananiev as archived at http://lkml.org/lkml/2007/2/8/337.

dio writes invalidate clean pages that intersect the written region so that
subsequent buffered reads go to disk to read the new data.  If this fails
the interface tries to tell the caller that the cache is inconsistent by
returning EIO.

Before this patch we had the problem where this invalidation failure would
clobber -EIOCBQUEUED as it made its way from fs/direct-io.c to fs/aio.c.
Both fs/aio.c and bio completion call aio_complete() and we reference freed
memory, usually oopsing.

This patch addresses this problem by invalidating before the write so that
we can cleanly return -EIO before ->direct_IO() has had a chance to return
-EIOCBQUEUED.

There is a compromise here.  During the dio write we can fault in mmap()ed
pages which intersect the written range with get_user_pages() if the user
provided them for the source buffer.  This is a crazy thing to do, but we
can make it mostly work in most cases by trying the invalidation again.
The compromise is that we won't return an error if this second invalidation
fails if it's an AIO write and we have -EIOCBQUEUED.

This was tested by having two processes race performing large O_DIRECT and
buffered ordered writes.  Within minutes ext3 would see a race between
ext3_releasepage() and jbd holding a reference on ordered data buffers and
would cause invalidation to fail, panicing the box.  The test can be found
in the 'aio_dio_bugs' test group in test.kernel.org/autotest.  After this
patch the test passes.

Signed-off-by: Zach Brown <zach.brown@oracle.com>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Cc: Leonid Ananiev <leonid.i.ananiev@linux.intel.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-16 19:25:04 -07:00
NeilBrown 29dbb3fc80 [PATCH] knfsd: stop NFSD writes from being broken into lots of little writes to filesystem
When NFSD receives a write request, the data is typically in a number of
1448 byte segments and writev is used to collect them together.

Unfortunately, generic_file_buffered_write passes these to the filesystem
one at a time, so an e.g.  32K over-write becomes a series of partial-page
writes to each page, causing the filesystem to have to pre-read those pages
- wasted effort.

generic_file_buffered_write handles one segment of the vector at a time as
it has to pre-fault in each segment to avoid deadlocks.  When writing from
kernel-space (and nfsd does) this is not an issue, so
generic_file_buffered_write does not need to break and iovec from nfsd into
little pieces.

This patch avoids the splitting when  get_fs is KERNEL_DS as it is
from NFSd.

This issue was introduced by commit 6527c2bdf1

Acked-by: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Norman Weathers <norman.r.weathers@conocophillips.com>
Cc: Vladimir V. Saveliev <vs@namesys.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16 08:14:01 -08:00
Robert P. J. Day 72fd4a35a8 [PATCH] Numerous fixes to kernel-doc info in source files.
A variety of (mostly) innocuous fixes to the embedded kernel-doc content in
source files, including:

  * make multi-line initial descriptions single line
  * denote some function names, constants and structs as such
  * change erroneous opening '/*' to '/**' in a few places
  * reword some text for clarity

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11 10:51:32 -08:00
Nick Piggin 62045305c2 [PATCH] mm: remove find_trylock_page
Remove find_trylock_page as per the removal schedule.

Signed-off-by: Nick Piggin <npiggin@suse.de>
[ Let's see if anybody screams ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-09 08:06:14 -08:00
Zach Brown 8459d86aff [PATCH] dio: only call aio_complete() after returning -EIOCBQUEUED
The only time it is safe to call aio_complete() is when the ->ki_retry
function returns -EIOCBQUEUED to the AIO core.  direct_io_worker() has
historically done this by relying on its caller to translate positive return
codes into -EIOCBQUEUED for the aio case.  It did this by trying to keep
conditionals in sync.  direct_io_worker() knew when finished_one_bio() was
going to call aio_complete().  It would reverse the test and wait and free the
dio in the cases it thought that finished_one_bio() wasn't going to.

Not surprisingly, it ended up getting it wrong.  'ret' could be a negative
errno from the submission path but it failed to communicate this to
finished_one_bio().  direct_io_worker() would return < 0, it's callers
wouldn't raise -EIOCBQUEUED, and aio_complete() would be called.  In the
future finished_one_bio()'s tests wouldn't reflect this and aio_complete()
would be called for a second time which can manifest as an oops.

The previous cleanups have whittled the sync and async completion paths down
to the point where we can collapse them and clearly reassert the invariant
that we must only call aio_complete() after returning -EIOCBQUEUED.
direct_io_worker() will only return -EIOCBQUEUED when it is not the last to
drop the dio refcount and the aio bio completion path will only call
aio_complete() when it is the last to drop the dio refcount.
direct_io_worker() can ensure that it is the last to drop the reference count
by waiting for bios to drain.  It does this for sync ops, of course, and for
partial dio writes that must fall back to buffered and for aio ops that saw
errors during submission.

This means that operations that end up waiting, even if they were issued as
aio ops, will not call aio_complete() from dio.  Instead we return the return
code of the operation and let the aio core call aio_complete().  This is
purposely done to fix a bug where AIO DIO file extensions would call
aio_complete() before their callers have a chance to update i_size.

Now that direct_io_worker() is explicitly returning -EIOCBQUEUED its callers
no longer have to translate for it.  XFS needs to be careful not to free
resources that will be used during AIO completion if -EIOCBQUEUED is returned.
 We maintain the previous behaviour of trying to write fs metadata for O_SYNC
aio+dio writes.

Signed-off-by: Zach Brown <zach.brown@oracle.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Suparna Bhattacharya <suparna@in.ibm.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Cc: <xfs-masters@oss.sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 09:57:21 -08:00
Josef "Jeff" Sipek d3ac7f892b [PATCH] mm: change uses of f_{dentry,vfsmnt} to use f_path
Change all the uses of f_{dentry,vfsmnt} to f_path.{dentry,mnt} in linux/mm/.

Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 08:28:43 -08:00
Ashwin Chaugule 098fe651f7 [PATCH] grab swap token reordered
Make sure the contention for the token happens _before_ any read-in and
kicks the swap-token algo only when the VM is under pressure.

Signed-off-by: Ashwin Chaugule <ashwin.chaugule@celunite.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:21 -08:00
Mark Fasheh d23a147bb6 [PATCH] Export should_remove_suid()
This helps us avoid replicating the same logic within file system drivers.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-12-01 18:28:38 -08:00
Nick Piggin 2ae88149a2 [PATCH] mm: clean up pagecache allocation
- Consolidate page_cache_alloc

- Fix splice: only the pagecache pages and filesystem data need to use
  mapping_gfp_mask.

- Fix grab_cache_page_nowait: same as splice, also honour NUMA placement.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-28 11:30:50 -07:00
Linus Torvalds 7b7fc708b5 Merge branch 'splice' of git://brick.kernel.dk/data/git/linux-2.6-block
* 'splice' of git://brick.kernel.dk/data/git/linux-2.6-block:
  [PATCH] Remove SUID when splicing into an inode
  [PATCH] Add lockless helpers for remove_suid()
  [PATCH] Introduce generic_file_splice_write_nolock()
  [PATCH] Take i_mutex in splice_from_pipe()
2006-10-21 10:01:52 -07:00
Nick Piggin 82591e6ea2 [PATCH] mm: more commenting on lock ordering
Clarify lockorder comments now that sys_msync dropps mmap_sem before
calling do_fsync.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-20 10:26:44 -07:00
Jeff Moyer fb5527e68d [PATCH] direct-io: sync and invalidate file region when falling back to buffered write
When direct-io falls back to buffered write, it will just leave the dirty data
floating about in pagecache, pending regular writeback.

But normal direct-io semantics are that IO is synchronous, and that it leaves
no pagecache behind.

So change the fallback-to-buffered-write code to sync the file region and to
then strip away the pagecache, just as a regular direct-io write would do.

Acked-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Zach Brown <zach.brown@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-20 10:26:35 -07:00
Jens Axboe 01de85e057 [PATCH] Add lockless helpers for remove_suid()
Right now users have to grab i_mutex before calling remove_suid(), in the
unlikely event that a call to ->setattr() may be needed. Split up the
function in two parts:

- One to check if we need to remove suid
- One to actually remove it

The first we can call lockless.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2006-10-19 20:53:08 +02:00
Linus Torvalds 4a61f17378 Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6: (292 commits)
  [GFS2] Fix endian bug for de_type
  [GFS2] Initialize SELinux extended attributes at inode creation time.
  [GFS2] Move logging code into log.c (mostly)
  [GFS2] Mark nlink cleared so VFS sees it happen
  [GFS2] Two redundant casts removed
  [GFS2] Remove uneeded endian conversion
  [GFS2] Remove duplicate sb reading code
  [GFS2] Mark metadata reads for blktrace
  [GFS2] Remove iflags.h, use FS_
  [GFS2] Fix code style/indent in ops_file.c
  [GFS2] streamline-generic_file_-interfaces-and-filemap gfs fix
  [GFS2] Remove readv/writev methods and use aio_read/aio_write instead (gfs bits)
  [GFS2] inode-diet: Eliminate i_blksize from the inode structure
  [GFS2] inode_diet: Replace inode.u.generic_ip with inode.i_private (gfs)
  [GFS2] Fix typo in last patch
  [GFS2] Fix direct i/o logic in filemap.c
  [GFS2] Fix bug in Makefiles for lock modules
  [GFS2] Remove (extra) fs_subsys declaration
  [GFS2/DLM] Fix trailing whitespace
  [GFS2] Tidy up meta_io code
  ...
2006-10-04 09:06:16 -07:00
Henrik Kretzschmar b2abacf3a2 [PATCH] mm: fix in kerneldoc
Fixes an kerneldoc error.

Signed-off-by: Henrik Kretzschmar <henne@nachtwindheim.de>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-04 07:55:12 -07:00
Steven Whitehouse 59458f40e2 Merge branch 'master' into gfs2 2006-10-02 08:45:08 -04:00
Badari Pulavarty 543ade1fc9 [PATCH] Streamline generic_file_* interfaces and filemap cleanups
This patch cleans up generic_file_*_read/write() interfaces.  Christoph
Hellwig gave me the idea for this clean ups.

In a nutshell, all filesystems should set .aio_read/.aio_write methods and use
do_sync_read/ do_sync_write() as their .read/.write methods.  This allows us
to cleanup all variants of generic_file_* routines.

Final available interfaces:

generic_file_aio_read() - read handler
generic_file_aio_write() - write handler
generic_file_aio_write_nolock() - no lock write handler

__generic_file_aio_write_nolock() - internal worker routine

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:28 -07:00
Badari Pulavarty ee0b3e671b [PATCH] Remove readv/writev methods and use aio_read/aio_write instead
This patch removes readv() and writev() methods and replaces them with
aio_read()/aio_write() methods.

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:28 -07:00
Badari Pulavarty 027445c372 [PATCH] Vectorize aio_read/aio_write fileop methods
This patch vectorizes aio_read() and aio_write() methods to prepare for
collapsing all aio & vectored operations into one interface - which is
aio_read()/aio_write().

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Michael Holzheu <HOLZHEU@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:28 -07:00
David Howells 9361401eb7 [PATCH] BLOCK: Make it possible to disable the block layer [try #6]
Make it possible to disable the block layer.  Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.

This patch does the following:

 (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
     support.

 (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
     an item that uses the block layer.  This includes:

     (*) Block I/O tracing.

     (*) Disk partition code.

     (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.

     (*) The SCSI layer.  As far as I can tell, even SCSI chardevs use the
     	 block layer to do scheduling.  Some drivers that use SCSI facilities -
     	 such as USB storage - end up disabled indirectly from this.

     (*) Various block-based device drivers, such as IDE and the old CDROM
     	 drivers.

     (*) MTD blockdev handling and FTL.

     (*) JFFS - which uses set_bdev_super(), something it could avoid doing by
     	 taking a leaf out of JFFS2's book.

 (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
     linux/elevator.h contingent on CONFIG_BLOCK being set.  sector_div() is,
     however, still used in places, and so is still available.

 (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
     parts of linux/fs.h.

 (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.

 (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.

 (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
     is not enabled.

 (*) fs/no-block.c is created to hold out-of-line stubs and things that are
     required when CONFIG_BLOCK is not set:

     (*) Default blockdev file operations (to give error ENODEV on opening).

 (*) Makes some /proc changes:

     (*) /proc/devices does not list any blockdevs.

     (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.

 (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.

 (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
     given command other than Q_SYNC or if a special device is specified.

 (*) In init/do_mounts.c, no reference is made to the blockdev routines if
     CONFIG_BLOCK is not defined.  This does not prohibit NFS roots or JFFS2.

 (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
     error ENOSYS by way of cond_syscall if so).

 (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
     CONFIG_BLOCK is not set, since they can't then happen.

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30 20:52:31 +02:00
David Howells cf9a2ae8d4 [PATCH] BLOCK: Move functions out of buffer code [try #6]
Move some functions out of the buffering code that aren't strictly buffering
specific.  This is a precursor to being able to disable the block layer.

 (*) Moved some stuff out of fs/buffer.c:

     (*) The file sync and general sync stuff moved to fs/sync.c.

     (*) The superblock sync stuff moved to fs/super.c.

     (*) do_invalidatepage() moved to mm/truncate.c.

     (*) try_to_release_page() moved to mm/filemap.c.

 (*) Moved some related declarations between header files:

     (*) declarations for do_invalidatepage() and try_to_release_page() moved
     	 to linux/mm.h.

     (*) __set_page_dirty_buffers() moved to linux/buffer_head.h.

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30 20:31:19 +02:00
Adam Litke 79f5acf5d7 [PATCH] mm: make filemap_nopage use NOPAGE_SIGBUS
Don't open-code NOPAGE_SIGBUS.

Signed-off-by: Adam Litke <agl@us.ibm.com>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:18:03 -07:00
Steven Whitehouse 185a257f2f Merge branch 'master' into gfs2 2006-09-28 08:29:59 -04:00
Steven Whitehouse 3f1a9aaeff [GFS2] Fix typo in last patch
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-09-27 14:52:48 -04:00
Steven Whitehouse 0e0bcae3bf [GFS2] Fix direct i/o logic in filemap.c
We shouldn't mark the file accessed in the case that it
wasn't accessed.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-09-27 14:45:07 -04:00
Nick Piggin da6052f7b3 [PATCH] update some mm/ comments
Let's try to keep mm/ comments more useful and up to date. This is a start.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:49 -07:00
Nick Piggin db37648cd6 [PATCH] mm: non syncing lock_page()
lock_page needs the caller to have a reference on the page->mapping inode
due to sync_page, ergo set_page_dirty_lock is obviously buggy according to
its comments.

Solve it by introducing a new lock_page_nosync which does not do a sync_page.

akpm: unpleasant solution to an unpleasant problem.  If it goes wrong it could
cause great slowdowns while the lock_page() caller waits for kblockd to
perform the unplug.  And if a filesystem has special sync_page() requirements
(none presently do), permanent hangs are possible.

otoh, set_page_dirty_lock() is usually (always?) called against userspace
pages.  They are always up-to-date, so there shouldn't be any pending read I/O
against these pages.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:48 -07:00
Steven Whitehouse b1b934d31d Merge branch 'master' 2006-07-31 08:59:59 -04:00
Andi Kleen b83a8e64fd [PATCH] MM: Remove rogue readahead printk
For some reason it triggers always with NFS root and spams the kernel
logs of my nfs root boxes a lot.

Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-29 20:59:55 -07:00
Steven Whitehouse a9e5f4d078 [GFS2] Alter direct I/O path
As per comments received, alter the GFS2 direct I/O path so that
it uses the standard read functions "out of the box". Needs a
small change to one of the VFS functions. This reduces the size
of the code quite a lot and also removes the need for one new export.

Some more work remains to be done, but this is the bones of the
thing.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-07-25 17:24:12 -04:00
Steven Whitehouse 0a1340c185 Merge rsync://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Conflicts:

	include/linux/kernel.h
2006-07-03 10:25:08 -04:00
Linus Torvalds 22a3e233ca Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial
* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial:
  Remove obsolete #include <linux/config.h>
  remove obsolete swsusp_encrypt
  arch/arm26/Kconfig typos
  Documentation/IPMI typos
  Kconfig: Typos in net/sched/Kconfig
  v9fs: do not include linux/version.h
  Documentation/DocBook/mtdnand.tmpl: typo fixes
  typo fixes: specfic -> specific
  typo fixes in Documentation/networking/pktgen.txt
  typo fixes: occuring -> occurring
  typo fixes: infomation -> information
  typo fixes: disadvantadge -> disadvantage
  typo fixes: aquire -> acquire
  typo fixes: mecanism -> mechanism
  typo fixes: bandwith -> bandwidth
  fix a typo in the RTC_CLASS help text
  smb is no longer maintained

Manually merged trivial conflict in arch/um/kernel/vmlinux.lds.S
2006-06-30 15:39:30 -07:00
Christoph Lameter f8891e5e1f [PATCH] Light weight event counters
The remaining counters in page_state after the zoned VM counter patches
have been applied are all just for show in /proc/vmstat.  They have no
essential function for the VM.

We use a simple increment of per cpu variables.  In order to avoid the most
severe races we disable preempt.  Preempt does not prevent the race between
an increment and an interrupt handler incrementing the same statistics
counter.  However, that race is exceedingly rare, we may only loose one
increment or so and there is no requirement (at least not in kernel) that
the vm event counters have to be accurate.

In the non preempt case this results in a simple increment for each
counter.  For many architectures this will be reduced by the compiler to a
single instruction.  This single instruction is atomic for i386 and x86_64.
 And therefore even the rare race condition in an interrupt is avoided for
both architectures in most cases.

The patchset also adds an off switch for embedded systems that allows a
building of linux kernels without these counters.

The implementation of these counters is through inline code that hopefully
results in only a single instruction increment instruction being emitted
(i386, x86_64) or in the increment being hidden though instruction
concurrency (EPIC architectures such as ia64 can get that done).

Benefits:
- VM event counter operations usually reduce to a single inline instruction
  on i386 and x86_64.
- No interrupt disable, only preempt disable for the preempt case.
  Preempt disable can also be avoided by moving the counter into a spinlock.
- Handling is similar to zoned VM counters.
- Simple and easily extendable.
- Can be omitted to reduce memory use for embedded use.

References:

RFC http://marc.theaimsgroup.com/?l=linux-kernel&m=113512330605497&w=2
RFC http://marc.theaimsgroup.com/?l=linux-kernel&m=114988082814934&w=2
local_t http://marc.theaimsgroup.com/?l=linux-kernel&m=114991748606690&w=2
V2 http://marc.theaimsgroup.com/?t=115014808400007&r=1&w=2
V3 http://marc.theaimsgroup.com/?l=linux-kernel&m=115024767022346&w=2
V4 http://marc.theaimsgroup.com/?l=linux-kernel&m=115047968808926&w=2

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30 11:25:36 -07:00
Christoph Lameter 347ce434d5 [PATCH] zoned vm counters: conversion of nr_pagecache to per zone counter
Currently a single atomic variable is used to establish the size of the page
cache in the whole machine.  The zoned VM counters have the same method of
implementation as the nr_pagecache code but also allow the determination of
the pagecache size per zone.

Remove the special implementation for nr_pagecache and make it a zoned counter
named NR_FILE_PAGES.

Updates of the page cache counters are always performed with interrupts off.
We can therefore use the __ variant here.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30 11:25:34 -07:00
Jörn Engel 6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00