linux.git/fs/buffer.c, branch v2.6.20

[PATCH] Fix try_to_free_buffer() locking

2007-01-30T04:20:42+00:00

Fix commit ecdfc9787fe527491baefc22dce8b2dbd5b2908d

Not to put too fine a point on it, but in a nutshell...

	__set_page_dirty_buffers() | try_to_free_buffers()
	---------------------------+---------------------------
	                           | spin_lock(private_lock);
	                           | drop_bufers()
	                           | spin_unlock(private_lock);
	spin_lock(private_lock)    |
	!page_has_buffers()        |
	spin_unlock(private_lock)  |
	SetPageDirty()             |
	                           | cancel_dirty_page()

                          oops!

Signed-off-by: Nick Piggin 
Acked-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Resurrect 'try_to_free_buffers()' VM hackery

2007-01-26T20:47:06+00:00

It's not pretty, but it appears that ext3 with data=journal will clean
pages without ever actually telling the VM that they are clean.  This,
in turn, will result in the VM (and balance_dirty_pages() in particular)
to never realize that the pages got cleaned, and wait forever for an
event that already happened.

Technically, this seems to be a problem with ext3 itself, but it used to
be hidden by 'try_to_free_buffers()' noticing this situation on its own,
and just working around the filesystem problem.

This commit re-instates that hack, in order to avoid a regression for
the 2.6.20 release. This fixes bugzilla 7844:

	http://bugzilla.kernel.org/show_bug.cgi?id=7844

Peter Zijlstra points out that we should probably retain the debugging
code that this removes from cancel_dirty_page(), and I agree, but for
the imminent release we might as well just silence the warning too
(since it's not a new bug: anything that triggers that warning has been
around forever).

Acked-by: Randy Dunlap 
Acked-by: Jens Axboe 
Acked-by: Peter Zijlstra 
Cc: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Revert bd_mount_mutex back to a semaphore

2007-01-12T02:18:21+00:00

Revert bd_mount_mutex back to a semaphore so that xfs_freeze -f /mnt/newtest;
xfs_freeze -u /mnt/newtest works safely and doesn't produce lockdep warnings.

(XFS unlocks the semaphore from a different task, by design.  The mutex
code warns about this)

Signed-off-by: Dave Chinner 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Clean up and make try_to_free_buffers() not race with dirty pages

2006-12-21T17:04:31+00:00

This is preparatory work in our continuing saga on some hard-to-trigger
file corruption with shared writable mmap() after the dirty page
tracking changes (commit d08b3851da41d0ee60851f2c75b118e1f7a5fc89 etc)
were merged.

Signed-off-by: Linus Torvalds

[PATCH] io-accounting: write-cancel accounting

2006-12-10T17:55:41+00:00

Account for the number of byte writes which this process caused to not happen
after all.

Cc: Jay Lan 
Cc: Shailabh Nagar 
Cc: Balbir Singh 
Cc: Chris Sturtivant 
Cc: Tony Ernst 
Cc: Guillaume Thouvenin 
Cc: David Wright 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] io-accounting: write accounting

2006-12-10T17:55:41+00:00

Accounting writes is fairly simple: whenever a process flips a page from clean
to dirty, we accuse it of having caused a write to underlying storage of
PAGE_CACHE_SIZE bytes.

This may overestimate the amount of writing: the page-dirtying may cause only
one buffer_head's worth of writeout.  Fixing that is possible, but probably a
bit messy and isn't obviously important.

Cc: Jay Lan 
Cc: Shailabh Nagar 
Cc: Balbir Singh 
Cc: Chris Sturtivant 
Cc: Tony Ernst 
Cc: Guillaume Thouvenin 
Cc: David Wright 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] clean up __set_page_dirty_nobuffers()

2006-12-10T17:55:41+00:00

Save a tabstop in __set_page_dirty_nobuffers() and __set_page_dirty_buffers()
and a few other places.  No functional changes.

Cc: Jay Lan 
Cc: Shailabh Nagar 
Cc: Balbir Singh 
Cc: Chris Sturtivant 
Cc: Tony Ernst 
Cc: Guillaume Thouvenin 
Cc: David Wright 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] hotplug CPU: clean up hotcpu_notifier() use

2006-12-07T16:39:39+00:00

There was lots of #ifdef noise in the kernel due to hotcpu_notifier(fn,
prio) not correctly marking 'fn' as used in the !HOTPLUG_CPU case, and thus
generating compiler warnings of unused symbols, hence forcing people to add
#ifdefs.

the compiler can skip truly unused functions just fine:

    text    data     bss     dec     hex filename
 1624412  728710 3674856 6027978  5bfaca vmlinux.before
 1624412  728710 3674856 6027978  5bfaca vmlinux.after

[akpm@osdl.org: topology.c fix]
Signed-off-by: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] slab: remove kmem_cache_t

2006-12-07T16:39:25+00:00

Replace all uses of kmem_cache_t with struct kmem_cache.

The patch was generated using the following script:

	#!/bin/sh
	#
	# Replace one string by another in all the kernel sources.
	#

	set -e

	for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do
		quilt add $file
		sed -e "1,\$s/$1/$2/g" $file >/tmp/$$
		mv /tmp/$$ $file
		quilt refresh
	done

The script was run like this

	sh replace kmem_cache_t "struct kmem_cache"

Signed-off-by: Christoph Lameter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Fix IO error reporting on fsync()

2006-10-17T15:18:46+00:00

When IO error happens on metadata buffer, buffer is freed from memory and
later fsync() is called, filesystems like ext2 fail to report EIO.  We

solve the problem by introducing a pointer to associated address space into
the buffer_head.  When a buffer is removed from a list of metadata buffers
associated with an address space, IO error is transferred from the buffer to
the address space, so that fsync can later report it.

Signed-off-by: Jan Kara 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds