linux.git/drivers/md/raid0.c, branch v4.0-rc2

md: rename ->stop to ->free

2015-02-03T21:35:52+00:00

Now that the ->stop function only frees the private data,
rename is accordingly.

Also pass in the private pointer as an arg rather than using
mddev->private.  This flexibility will be useful in level_store().

Finally, don't clear ->private.  It doesn't make sense to clear
it seeing that isn't what we free, and it is no longer necessary
to clear ->private (it was some time ago before  ->to_remove was
introduced).

Setting ->to_remove in ->free() is a bit of a wart, but not a
big problem at the moment.

Signed-off-by: NeilBrown

md: split detach operation out from ->stop.

2015-02-03T21:35:52+00:00

Each md personality has a 'stop' operation which does two
things:
 1/ it finalizes some aspects of the array to ensure nothing
    is accessing the ->private data
 2/ it frees the ->private data.

All the steps in '1' can apply to all arrays and so can be
performed in common code.

This is useful as in the case where we change the personality which
manages an array (in level_store()), it would be helpful to do
step 1 early, and step 2 later.

So split the 'step 1' functionality out into a new mddev_detach().

Signed-off-by: NeilBrown

md: make merge_bvec_fn more robust in face of personality changes.

2015-02-03T21:35:52+00:00

There is no locking around calls to merge_bvec_fn(), so
it is possible that calls which coincide with a level (or personality)
change could go wrong.

So create a central dispatch point for these functions and use
rcu_read_lock().
If the array is suspended, reject any merge that can be rejected.
If not, we know it is safe to call the function.

Signed-off-by: NeilBrown

md: make ->congested robust against personality changes.

2015-02-03T21:35:52+00:00

There is currently no locking around calls to the 'congested'
bdi function.  If called at an awkward time while an array is
being converted from one level (or personality) to another, there
is a tiny chance of running code in an unreferenced module etc.

So add a 'congested' function to the md_personality operations
structure, and call it with appropriate locking from a central
'mddev_congested'.

When the array personality is changing the array will be 'suspended'
so no IO is processed.
If mddev_congested detects this, it simply reports that the
array is congested, which is a safe guess.
As mddev_suspend calls synchronize_rcu(), mddev_congested can
avoid races by included the whole call inside an rcu_read_lock()
region.
This require that the congested functions for all subordinate devices
can be run under rcu_lock.  Fortunately this is the case.

Signed-off-by: NeilBrown

md: remove unwanted white space from md.c

2014-10-14T02:08:29+00:00

My editor shows much of this is RED.

Signed-off-by: NeilBrown

md/raid0: check for bitmap compatability when changing raid levels.

2014-08-08T05:33:17+00:00

If an array has a bitmap, then it cannot be converted to raid0.

Reported-by: Xiao Ni 
Signed-off-by: NeilBrown

block: Introduce new bio_split()

2013-11-24T06:33:57+00:00

The new bio_split() can split arbitrary bios - it's not restricted to
single page bios, like the old bio_split() (previously renamed to
bio_pair_split()). It also has different semantics - it doesn't allocate
a struct bio_pair, leaving it up to the caller to handle completions.

Then convert the existing bio_pair_split() users to the new bio_split()
- and also nvme, which was open coding bio splitting.

(We have to take that BUG_ON() out of bio_integrity_trim() because this
bio_split() needs to use it, and there's no reason it has to be used on
bios marked as cloned; BIO_CLONED doesn't seem to have clearly
documented semantics anyways.)

Signed-off-by: Kent Overstreet 
Cc: Jens Axboe 
Cc: Martin K. Petersen 
Cc: Matthew Wilcox 
Cc: Keith Busch 
Cc: Vishal Verma 
Cc: Jiri Kosina 
Cc: Neil Brown

block: Rename bio_split() -> bio_pair_split()

2013-11-24T06:33:56+00:00

This is prep work for introducing a more general bio_split().

Signed-off-by: Kent Overstreet 
Cc: Jens Axboe 
Cc: NeilBrown 
Cc: Alasdair Kergon 
Cc: Lars Ellenberg 
Cc: Peter Osterlund 
Cc: Sage Weil

block: Kill bio_segments()/bi_vcnt usage

2013-11-24T06:33:51+00:00

When we start sharing biovecs, keeping bi_vcnt accurate for splits is
going to be error prone - and unnecessary, if we refactor some code.

So bio_segments() has to go - but most of the existing users just needed
to know if the bio had multiple segments, which is easier - add a
bio_multiple_segments() for them.

(Two of the current uses of bio_segments() are going to go away in a
couple patches, but the current implementation of bio_segments() is
unsafe as soon as we start doing driver conversions for immutable
biovecs - so implement a dumb version for bisectability, it'll go away
in a couple patches)

Signed-off-by: Kent Overstreet 
Cc: Jens Axboe 
Cc: Neil Brown 
Cc: Nagalakshmi Nandigama 
Cc: Sreekanth Reddy 
Cc: "James E.J. Bottomley"

block: Abstract out bvec iterator

2013-11-24T06:33:47+00:00

Immutable biovecs are going to require an explicit iterator. To
implement immutable bvecs, a later patch is going to add a bi_bvec_done
member to this struct; for now, this patch effectively just renames
things.

Signed-off-by: Kent Overstreet 
Cc: Jens Axboe 
Cc: Geert Uytterhoeven 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: "Ed L. Cashin" 
Cc: Nick Piggin 
Cc: Lars Ellenberg 
Cc: Jiri Kosina 
Cc: Matthew Wilcox 
Cc: Geoff Levand 
Cc: Yehuda Sadeh 
Cc: Sage Weil 
Cc: Alex Elder 
Cc: ceph-devel@vger.kernel.org
Cc: Joshua Morris 
Cc: Philip Kelleher 
Cc: Rusty Russell 
Cc: "Michael S. Tsirkin" 
Cc: Konrad Rzeszutek Wilk 
Cc: Jeremy Fitzhardinge 
Cc: Neil Brown 
Cc: Alasdair Kergon 
Cc: Mike Snitzer 
Cc: dm-devel@redhat.com
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: linux390@de.ibm.com
Cc: Boaz Harrosh 
Cc: Benny Halevy 
Cc: "James E.J. Bottomley" 
Cc: Greg Kroah-Hartman 
Cc: "Nicholas A. Bellinger" 
Cc: Alexander Viro 
Cc: Chris Mason 
Cc: "Theodore Ts'o" 
Cc: Andreas Dilger 
Cc: Jaegeuk Kim 
Cc: Steven Whitehouse 
Cc: Dave Kleikamp 
Cc: Joern Engel 
Cc: Prasad Joshi 
Cc: Trond Myklebust 
Cc: KONISHI Ryusuke 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Ben Myers 
Cc: xfs@oss.sgi.com
Cc: Steven Rostedt 
Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Len Brown 
Cc: Pavel Machek 
Cc: "Rafael J. Wysocki" 
Cc: Herton Ronaldo Krzesinski 
Cc: Ben Hutchings 
Cc: Andrew Morton 
Cc: Guo Chao 
Cc: Tejun Heo 
Cc: Asai Thambi S P 
Cc: Selvan Mani 
Cc: Sam Bradshaw 
Cc: Wei Yongjun 
Cc: "Roger Pau Monné" 
Cc: Jan Beulich 
Cc: Stefano Stabellini 
Cc: Ian Campbell 
Cc: Sebastian Ott 
Cc: Christian Borntraeger 
Cc: Minchan Kim 
Cc: Jiang Liu 
Cc: Nitin Gupta 
Cc: Jerome Marchand 
Cc: Joe Perches 
Cc: Peng Tao 
Cc: Andy Adamson 
Cc: fanchaoting 
Cc: Jie Liu 
Cc: Sunil Mushran 
Cc: "Martin K. Petersen" 
Cc: Namjae Jeon 
Cc: Pankaj Kumar 
Cc: Dan Magenheimer 
Cc: Mel Gorman 6