New device-mapper patchset for 2.5.51

If anyone was experiencing problems with dm could they please try this patchset and give me feedback.

Thanks,

- Joe

http://people.sistina.com/~thornber/patches/2.5-stable/2.5.51/2.5.51-dm-3.tar.bz2

Changes
-------

Revision 1:
Four constants:

     DM_DIR,
     DM_MAX_TYPE_NAME,
     DM_NAME_LEN,
     DM_UUID_LEN

Were being declared in device-mapper.h, these are all specific to the ioctl interface, so they've been moved to dm-ioctl.h. Nobody in userland should ever include <linux/device-mapper.h> so remove ifdef __KERNEL guards.

Revision 2:
An error value was not being checked correctly in open_dev(). [Kevin Corry]

Revision 3:
Return -ENOTBLK if lookup_device() finds the inode, but it is not a block device. [Cristoph Hellwig]

Revision 4:
No need to validate the parameters if we are doing a REMOVE_ALL command.

Revision 5:
check_device_area was comparing the bytes with sectors. [Stefan Lauterbach]

Revision 6:
minor change for dm-strip.c. Tests for correct chunksize before it allocates the stripe context. [Heinz Mauelshagen]

Revision 7:
There's a bug in the dm-stripe.c constructor failing top check if enough destinations are handed in. [Heinz Mauelshagen]

Revision 8:
Give each device its own io mempool to avoid a potential deadlock with stacked devices. [HM + EJT]

Revision 9:
queue_io() was checking the DMF_SUSPENDED flag rather than the new DMF_BLOCK_IO flag. This meant suspend could deadlock under load.

Revision 10:
dm_suspend(): Stop holding the read lock around the while loop that waits for pending io to complete.

Revision 11:
Add a blk_run_queues() call to encourage pending io to flush when we're doing a dm_suspend().

Revision 12:
dec_pending(): only bother spin locking if io->error is going to be updated. [Kevin Corry]

Revision 13:
md->pending was being incremented for each clone rather than just once. [Kevin Corry]

Revision 14:
Some fields in the duplicated bio weren't being set up properly in __split_page(). [Kevin Corry]

Revision 15:
Remove some paranoia in highmem.c, need to check this with Jens Axboe.

Revision 16:
Remove verbose debug message 'Splitting page'.

Revision 17:
o If there's an error you still need to call bio_endio with bio->bi_size as the 'done' param.

o Simplify clone_endio.

[Kevin Corry]

Revision 18:
The block layer does not honour bio->bi_size when issuing io, instead it performs io to the complete bvecs. This means we have to change the bio splitting code slightly.

Given a bio we repeatedly apply one of the following three operations until there is no more io left in the bio:

1) The remaining io does not cross an io/target boundary, so just create a clone and issue all of the io.

2) There are some bvecs at the start of the bio that are not split by a target boundary. Create a clone for these bvecs only.

3) The first bvec needs splitting, use bio_alloc() to create *two* bios, one for the first half of the bvec, the other for the second half. A bvec can never contain more than one boundary.

Revision 19:
For large bios it was possible to look up the wrong target. Bug introduced by the recent splitting changes.

Revision 20:
The linear target was getting the start sector wrong when doing a dm_get_device(). [Kevin Corry]

	Hi;

	I havent tried 2.5.51 vanila, but 2.5.51 with dm-3 patch

is working well so far for me on LVM system. (All other 2.5 kernels tried would hit a BUG()-- already reported.)
If anyone wants me to recommend some sort of stress test
let me know; Ive simpley constructed and populated several fileystems, md5sum'ed all the files, bzip2'd them, rm'd them, etc. Then several hours of looping kernel compiles.
Thanks for the work of the contributers.

Paul
[email protected]