forward-ported from 2.4

into hostme.bitkeeper.com:/ua/repos/g/gkernel/alpha-2.5

Linus,

The attached patch adds a Documentation/preempt-locking.txt file which
describes the new locking rules wrt preemptive kernels (ie, watch
per-CPU data, etc).  It also updates a CREDITS entry and adds some
comments.

Patch is against 2.5.4-pre5, please apply.

	Robert Love

Another lseek fix, spotted by Dave Hansen @ IBM.  Missing a
corresponding lock_kernel for an unlock_kernel.  Patch against
2.5.4-pre5, please apply.  Thanks,

	Robert Love

into vaio.(none):/home/kai/kernel/linux-2.5.isdn

adapter driver initializes before the USB layer -> Oops

(was isdn.a before, but there's no need to use an archive here)

in drivers/isdn/Config.help

into rum.normnet.org:/spare/vanilla/net-drivers-2.5

into rum.normnet.org:/spare/vanilla/net-drivers-2.5

- Fix bug in scripts that was causing CDRW hang
- add sense buffer length initialisation
- update lasi700 to new driver model and fix rmmod hang
- add correct MCA reporting to D700 driver

into hostme.bitkeeper.com:/ua/repos/g/gkernel/net-drivers-2.5

	Patch converts a bunch of places that hadn't been caught when
->s_id was introduced.  Please, apply.

	affs digs in blk_size[] to find the size of device (it
has its analog of superblock living in the middle of disk).  That
information is available in ->s_bdev->bd_inode->i_size - no need
to mess with major/minor/arrays to get it.

	/proc/modules switched to use of seq_file, cleaned up.

	Straightforward rewrite to seq_file.

	Please, apply.  Otherwise we eat quota like there's no tomorrow ;-/

into rum.normnet.org:/spare/vanilla/net-drivers-2.5

It compiles in -pre5 but doesn't work unless you also apply the patch
below. Without this patch, bus_id will be empty which makes
device_register fail.

  update

into home.transmeta.com:/home/torvalds/v2.5/linux

Big bits first, I'll redo the smaller bits tomorrow after some sleep.
Same as last time, rediffed against pre5

into home.transmeta.com:/home/torvalds/v2.5/linux

There are a couple of errors in the DMA changes to the
aha1542.c driver that appeared in 2.5.4pre3:

- a typo (BUF vs BUS)
- a macro handed a page instead of a scatterlist
- printk format length mismatch

Paul.

Make dentry and ->i_sem manipulations in driverfs explicit.  Something
is seriously rotten there and real fixes will take non-trivial work
(e.g, I suspect that we actually ought to kill driverfs_rename() - at
least cross-directory one for regular files, maybe completely).  This
patch simply cleans the ground. 

	Mostly cosmetical cleanup - sane variable names, etc.
That's pretty much it for balloc.c cleanups - stuff after that
will be about decent threading.

in ext2_new_block() inode->i_sb can't be NULL.  Dead code removed.

merged returns in ext2_new_block()

in ext2_new_block() added a local variable (sbi) for sb->u.ext2_sb;
users converted. 

calculation of prealloc_goal moved into beginning of function. 

new local variable (block).  Initialized to 0, set to the number of
allocated block only when we are known to be successful. 
ext2_new_block() returns the value of 'block' now.  As the result, out:
is gone - it's identical to out_unlock now. 

check for block being chosen past the end of disk had been moved up No
sense to check that after we had done the preallocations... 

quota allocation taken into the beginning of ext2_new_block().  we put
the number of blocks we'd reserved into dq_alloc and then decrement it
each time old code would do DQUOT_ALLOC/increment when it would do
DQUOT_FREE.  On the exit we release dq_alloc blocks I.e.  all
allocations are pushed into the beginning and all freeing - to the end. 

now that we had moved the last possible point of failure up, we can do
the same with assignment of final result to block. 

code that does allocation within a group had been taken out into a
helper - grab_block(map, size, goal). 

decrementing fs-wide free blocks count moved into the beginning of
function.  We try to reserve up to dq_alloc blocks - amount we _can_
grab is limited by the actual free space and root-reserved percentage. 
That logics had been taken into a helper - reserve_blocks(sb, amount). 
Number of blocks we had managed to reserve is put into es_alloc.  When
we actually grab a block, es_alloc is decremented.  Upon the exit we
release the leftovers.  Old code didn't honor 'reserved for root' limit
when doing prealloc - now that had been fixed. 

EXT2_BLOCKS_PER_GROUP(sb) put into a local variable (group_size)

similar "reserve and release leftovers in the end" scheme for group
(i.e.  we try to reserve as much as we want in the group, then count how
much had been used up and release the leftovers in the end). 

cleaned up the preallocation loop. 

minor cleanup: update 'freed' only after we finish with group

in ext2_free_blocks() inode->i_sb can't be NULL; dead code removed.

new helper - group_release_blocks(desc, bh, count); updates free blocks
count for given group ext2_free_blocks now counts the blocks freed in
group and updates the per-group free blocks count at once. 

we postpone releasing the quota until the end of ext2_free_blocks() and
do that at once. 

new helper function - release_blocks(sb, n); in ext2_free_blocks() we
count the blocks we'd freed and update the fs-wide count of free blocks
in the end - just before unlocking superblock.  instead of doing that
step at a time.

reviewed by ext2 folks

On Sat, 2002-02-09 at 01:43, Linus Torvalds wrote:

> That will clean up all your issues with header file ordering.

You are right, it did.  I removed all the sched.h dependencies and this
reduced the size of the patch greatly.  I now use current_thread_info()
and none of the header or include hackery from before.  I've tested this
with and without preemption enabled with success.

I appreciate your help with this.

Again, this is a minimal i386-only patch.  I have other arches,
documentation, etc.  Patch against 2.5.4-pre5.  Enjoy,

	Robert Love

to the current driver.