linux-stable.git/block/blk-lib.c, branch linux-3.19.y

block/blk-lib.c: make __blkdev_issue_zeroout static

2014-05-26T23:39:09+00:00

__blkdev_issue_zeroout is only used in blk-lib.c

Cc: Jens Axboe 
Cc: Andrew Morton 
Signed-off-by: Fabian Frederick 
Signed-off-by: Jens Axboe

block: add cond_resched() to potentially long running ioctl discard loop

2014-02-12T16:36:37+00:00

When mkfs issues a full device discard and the device only
supports discards of a smallish size, we can loop in
blkdev_issue_discard() for a long time. If preempt isn't enabled,
this can turn into a softlock situation and the kernel will
start complaining.

Add an explicit cond_resched() at the end of the loop to avoid
that.

Cc: stable@kernel.org
Signed-off-by: Jens Axboe

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

block: Do not call sector_div() with a 64-bit divisor

2013-11-08T16:04:46+00:00

do_div() (called by sector_div() if CONFIG_LBDAF=y) is meant for divisions
of 64-bit number by 32-bit numbers.  Passing 64-bit divisor types caused
issues in the past on 32-bit platforms, cfr. commit
ea077b1b96e073eac5c3c5590529e964767fc5f7 ("m68k: Truncate base in
do_div()").

As queue_limits.max_discard_sectors and .discard_granularity are unsigned
int, max_discard_sectors and granularity should be unsigned int.
As bdev_discard_alignment() returns int, alignment should be int.
Now 2 calls to sector_div() can be replaced by 32-bit arithmetic:
  - The 64-bit modulo operation can become a 32-bit modulo operation,
  - The 64-bit division and multiplication can be replaced by a 32-bit
    modulo operation and a subtraction.

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Jens Axboe

block: account iowait time when waiting for completion of IO request

2013-02-15T15:45:07+00:00

Using wait_for_completion() for waiting for a IO request to be executed
results in wrong iowait time accounting. For example, a system having
the only task doing write() and fdatasync() on a block device can be
reported being idle instead of iowaiting as it should because
blkdev_issue_flush() calls wait_for_completion() which in turn calls
schedule() that does not increment the iowait proc counter and thus does
not turn on iowait time accounting.

The patch makes block layer use wait_for_completion_io() instead of
wait_for_completion() where appropriate to account iowait time
correctly.

Signed-off-by: Vladimir Davydov 
Signed-off-by: Jens Axboe

block: add plug for blkdev_issue_discard

2012-12-14T19:46:04+00:00

Last post of this patch appears lost, so I resend this.

Now discard merge works, add plug for blkdev_issue_discard. This will help
discard request merge especially for raid0 case. In raid0, a big discard
request is split to small requests, and if correct plug is added, such small
requests can be merged in low layer.

Signed-off-by: Shaohua Li 
Signed-off-by: Jens Axboe

block: discard granularity might not be power of 2

2012-12-14T19:46:04+00:00

In MD raid case, discard granularity might not be power of 2, for example, a
4-disk raid5 has 3*chunk_size discard granularity. Correct the calculation for
such cases.

Reported-by: Neil Brown 
Signed-off-by: Shaohua Li 
Signed-off-by: Jens Axboe

block: Make blkdev_issue_zeroout use WRITE SAME

2012-09-20T12:31:49+00:00

If the device supports WRITE SAME, use that to optimize zeroing of
blocks. If the device does not support WRITE SAME or if the operation
fails, fall back to writing zeroes the old-fashioned way.

Signed-off-by: Martin K. Petersen 
Acked-by: Mike Snitzer 
Signed-off-by: Jens Axboe

block: Implement support for WRITE SAME

2012-09-20T12:31:45+00:00

The WRITE SAME command supported on some SCSI devices allows the same
block to be efficiently replicated throughout a block range. Only a
single logical block is transferred from the host and the storage device
writes the same data to all blocks described by the I/O.

This patch implements support for WRITE SAME in the block layer. The
blkdev_issue_write_same() function can be used by filesystems and block
drivers to replicate a buffer across a block range. This can be used to
efficiently initialize software RAID devices, etc.

Signed-off-by: Martin K. Petersen 
Acked-by: Mike Snitzer 
Signed-off-by: Jens Axboe

block: split discard into aligned requests

2012-08-02T07:48:50+00:00

When a disk has large discard_granularity and small max_discard_sectors,
discards are not split with optimal alignment.  In the limit case of
discard_granularity == max_discard_sectors, no request could be aligned
correctly, so in fact you might end up with no discarded logical blocks
at all.

Another example that helps showing the condition in the patch is with
discard_granularity == 64, max_discard_sectors == 128.  A request that is
submitted for 256 sectors 2..257 will be split in two: 2..129, 130..257.
However, only 2 aligned blocks out of 3 are included in the request;
128..191 may be left intact and not discarded.  With this patch, the
first request will be truncated to ensure good alignment of what's left,
and the split will be 2..127, 128..255, 256..257.  The patch will also
take into account the discard_alignment.

At most one extra request will be introduced, because the first request
will be reduced by at most granularity-1 sectors, and granularity
must be less than max_discard_sectors.  Subsequent requests will run
on round_down(max_discard_sectors, granularity) sectors, as in the
current code.

Signed-off-by: Paolo Bonzini 
Acked-by: Vivek Goyal 
Tested-by: Mike Snitzer 
Signed-off-by: Jens Axboe