linux-toradex.git/fs/mpage.c, branch v2.6.32.51

ext4: Properly initialize the buffer_head state

2009-05-13T19:13:42+00:00

These struct buffer_heads are allocated on the stack (and hence are
initialized with stack garbage).  They are only used to call a
get_blocks() function, so that's mostly OK, but b_state must be
initialized to be 0 so we don't have any unexpected BH_* flags set by
accident, such as BH_Unwritten or BH_Delay.

Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: "Theodore Ts'o"

Remove two unneeded exports and make two symbols static in fs/mpage.c

2009-04-01T11:38:54+00:00

Commit 29a814d2ee0e43c2980f33f91c1311ec06c0aa35 (vfs: add hooks for
ext4's delayed allocation support) exported the following functions

mpage_bio_submit()
__mpage_writepage()

for the benefit of ext4's delayed allocation support. Since commit
a1d6cc563bfdf1bf2829d3e6ce4d8b774251796b (ext4: Rework the
ext4_da_writepages() function), these functions are not used by the
ext4 driver anymore. However, the now unnecessary exports still
remain, and this patch removes those. Moreover, these two functions
can become static again.

The issue was spotted by namespacecheck.

Signed-off-by: Dmitri Vorobiev 
Reviewed-by: Aneesh Kumar K.V 
Signed-off-by: Al Viro

do_mpage_readpage(): remove useless clear_buffer_mapped() call

2009-01-06T23:59:01+00:00

It is known that buffer_mapped() is false in this code path.

Signed-off-by: Franck Bui-Huu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

do_mpage_readpage(): don't submit lots of small bios on boundary

2009-01-06T23:58:59+00:00

While tracing I/O patterns with blktrace (a great tool) a few weeks ago I
identified a minor issue in fs/mpage.c

As the comment above mpage_readpages() says, a fs's get_block function
will set BH_Boundary when it maps a block just before a block for which
extra I/O is required.

Since get_block() can map a range of pages, for all these pages the
BH_Boundary flag will be set.  But we only need to push what I/O we have
accumulated at the last block of this range.

This makes do_mpage_readpage() send out the largest possible bio instead
of a bunch of page-sized ones in the BH_Boundary case.

Signed-off-by: Miquel van Smoorenburg 
Cc: Nick Piggin 
Cc: Jens Axboe 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Remove Andrew Morton's old email accounts

2008-10-16T18:21:32+00:00

People can use the real name an an index into MAINTAINERS to find the
current email address.

Signed-off-by: Francois Cami 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

vfs: add hooks for ext4's delayed allocation support

2008-07-11T23:27:31+00:00

Export mpage_bio_submit() and __mpage_writepage() for the benefit of
ext4's delayed allocation support.   Also change __block_write_full_page
so that if buffers that have the BH_Delay flag set it will call
get_block() to get the physical block allocated, just as in the
!BH_Mapped case.

Signed-off-by: Alex Tomas 
Signed-off-by: "Theodore Ts'o"

docbook: fix filesystems.tmpl source files

2008-03-03T18:47:13+00:00

Fix docbook problems in filesystems.tmpl.
These cause the generated docbook to be incorrect.

Signed-off-by: Randy Dunlap 
Signed-off-by: Linus Torvalds

Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user

2008-02-05T17:44:13+00:00

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: Christoph Lameter 
Cc: Steven French 
Cc: Michael Halcrow 
Cc: 
Cc: Steven Whitehouse 
Cc: Trond Myklebust 
Cc: "J. Bruce Fields" 
Cc: Anton Altaparmakov 
Cc: Mark Fasheh 
Cc: David Chinner 
Cc: Michael Halcrow 
Cc: Steven French 
Cc: Steven Whitehouse 
Cc: Trond Myklebust 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: buffered write cleanup

2007-10-16T16:42:54+00:00

Quite a bit of code is used in maintaining these "cached pages" that are
probably pretty unlikely to get used. It would require a narrow race where
the page is inserted concurrently while this process is allocating a page
in order to create the spare page. Then a multi-page write into an uncached
part of the file, to make use of it.

Next, the buffered write path (and others) uses its own LRU pagevec when it
should be just using the per-CPU LRU pagevec (which will cut down on both data
and code size cacheline footprint). Also, these private LRU pagevecs are
emptied after just a very short time, in contrast with the per-CPU pagevecs
that are persistent. Net result: 7.3 times fewer lru_lock acquisitions required
to add the pages to pagecache for a bulk write (in 4K chunks).

[this gets rid of some cond_resched() calls in readahead.c and mpage.c due
 to clashes in -mm. What put them there, and why? ]

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

Drop 'size' argument from bio_endio and bi_end_io

2007-10-10T07:25:57+00:00

As bi_end_io is only called once when the reqeust is complete,
the 'size' argument is now redundant.  Remove it.

Now there is no need for bio_endio to subtract the size completed
from bi_size.  So don't do that either.

While we are at it, change bi_end_io to return void.

Signed-off-by: Neil Brown 
Signed-off-by: Jens Axboe