linux-toradex.git/drivers/md/bitmap.c, branch v2.6.20.21

[PATCH] md: Don't write more than is required of the last page of a bitmap

2007-08-15T08:02:21+00:00

It is possible that real data or metadata follows the bitmap
without full page alignment.
So limit the last write to be only the required number of bytes,
rounded up to the hard sector size of the device.

Signed-off-by: Neil Brown 
Signed-off-by: Chris Wright 
Signed-off-by: Greg Kroah-Hartman

Fix calculation for size of filemap_attr array in md/bitmap.

2007-04-13T20:47:03+00:00

If 'num_pages' were ever 1 more than a multiple of 8 (32bit platforms)
for of 16 (64 bit platforms). filemap_attr would be allocated one
'unsigned long' shorter than required.  We need a round-up in there.


Signed-off-by: Neil Brown 
Signed-off-by: Greg Kroah-Hartman

md: Avoid possible BUG_ON in md bitmap handling.

2007-03-09T18:50:20+00:00

md/bitmap tracks how many active write requests are pending on blocks
associated with each bit in the bitmap, so that it knows when it can
clear the bit (when count hits zero).

The counter has 14 bits of space, so if there are ever more than 16383,
we cannot cope.

Currently the code just calles BUG_ON as "all" drivers have request queue
limits much smaller than this.

However is seems that some don't.  Apparently some multipath configurations
can allow more than 16383 concurrent write requests.

So, in this unlikely situation, instead of calling BUG_ON we now wait
for the count to drop down a bit.  This requires a new wait_queue_head,
some waiting code, and a wakeup call.

Tested by limiting the counter to 20 instead of 16383 (writes go a lot slower
in that case...).

Signed-off-by: Neil Brown 
Signed-off-by: Greg Kroah-Hartman 

diff .prev/drivers/md/bitmap.c ./drivers/md/bitmap.c

[PATCH] md: avoid reading past the end of a bitmap file

2007-01-26T21:50:59+00:00

In most cases we check the size of the bitmap file before reading data from
it.  However when reading the superblock, we always read the first PAGE_SIZE
bytes, which might not always be appropriate.  So limit that read to the size
of the file if appropriate.

Also, we get the count of available bytes wrong in one place, so that too can
read past the end of the file.

Cc: "yang yin" 
Signed-off-by: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] struct path: convert md

2006-12-08T16:28:47+00:00

Signed-off-by: Josef Sipek 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] md: endian annotations for the bitmap superblock

2006-10-21T20:35:05+00:00

And a couple of bug fixes found by sparse.

Signed-off-by: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] md: use BUILD_BUG_ON

2006-10-11T18:14:26+00:00

Signed-off-by: Alexey Dobriyan 
Acked-by: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] md: use ffz instead of find_first_set to convert multiplier to shift

2006-10-03T15:04:18+00:00

find_first_set doesn't find the least-significant bit on bigendian machines,
so it is really wrong to use it.

ffs is closer, but takes an 'int' and we have a 'unsigned long'.  So use
ffz(~X) to convert a chunksize into a chunkshift.

Signed-off-by: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] md: new sysfs interface for setting bits in the write-intent-bitmap

2006-10-03T15:04:17+00:00

Add a new sysfs interface that allows the bitmap of an array to be dirtied.
The interface is write-only, and is used as follows:

echo "1000" > /sys/block/md2/md/bitmap

(dirty the bit for chunk 1000 [offset 0] in the in-memory and on-disk
bitmaps of array md2)

echo "1000-2000" > /sys/block/md1/md/bitmap

(dirty the bits for chunks 1000-2000 in md1's bitmap)

This is useful, for example, in cluster environments where you may need to
combine two disjoint bitmaps into one (following a server failure, after a
secondary server has taken over the array).  By combining the bitmaps on
the two servers, a full resync can be avoided (This was discussed on the
list back on March 18, 2005, "[PATCH 1/2] md bitmap bug fixes" thread).

Signed-off-by: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Remove obsolete #include

2006-06-30T17:25:36+00:00

Signed-off-by: Jörn Engel 
Signed-off-by: Adrian Bunk