linux-stable.git/block/bio.c, branch linux-4.6.y

mm, fs: remove remaining PAGE_CACHE_* and page_cache_{get,release} usage

2016-04-04T17:41:08+00:00

Mostly direct substitution with occasional adjustment or removing
outdated comments.

Signed-off-by: Kirill A. Shutemov 
Acked-by: Michal Hocko 
Signed-off-by: Linus Torvalds

mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros

2016-04-04T17:41:08+00:00

PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 -  << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ;

 -  >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov 
Acked-by: Michal Hocko 
Signed-off-by: Linus Torvalds

Merge branch 'for-4.6/core' of git://git.kernel.dk/linux-block

2016-03-18T23:43:11+00:00

Pull core block updates from Jens Axboe:
 "Here are the core block changes for this merge window.  Not a lot of
  exciting stuff going on in this round, most of the changes have been
  on the driver side of things.  That pull request is coming next.  This
  pull request contains:

   - A set of fixes for chained bio handling from Christoph.

   - A tag bounds check for blk-mq from Hannes, ensuring that we don't
     do something stupid if a device reports an invalid tag value.

   - A set of fixes/updates for the CFQ IO scheduler from Jan Kara.

   - A set of blk-mq fixes from Keith, adding support for dynamic
     hardware queues, and fixing init of max_dev_sectors for stacking
     devices.

   - A fix for the dynamic hw context from Ming.

   - Enabling of cgroup writeback support on a block device, from
     Shaohua"

* 'for-4.6/core' of git://git.kernel.dk/linux-block:
  blk-mq: add bounds check on tag-to-rq conversion
  block: bio_remaining_done() isn't unlikely
  block: cleanup bio_endio
  block: factor out chained bio completion
  block: don't unecessarily clobber bi_error for chained bios
  block-dev: enable writeback cgroup support
  blk-mq: Fix NULL pointer updating nr_requests
  blk-mq: mark request queue as mq asap
  block: Initialize max_dev_sectors to 0
  blk-mq: dynamic h/w context count
  cfq-iosched: Allow parent cgroup to preempt its child
  cfq-iosched: Allow sync noidle workloads to preempt each other
  cfq-iosched: Reorder checks in cfq_should_preempt()
  cfq-iosched: Don't group_idle if cfqq has big thinktime

block: bio_remaining_done() isn't unlikely

2016-03-14T14:55:25+00:00

We use bio chaining during most I/Os these days due to the delayed
bio splitting.  Additionally XFS will start using it, and there is
a pending direct I/O rewrite also making heavy use for it.  Don't
pretend it's always unlikely, and let the branch predictor do it's
job instead.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: cleanup bio_endio

2016-03-14T14:55:24+00:00

Replace the while loop that unecessarily checks for a NULL bio in the fast
path with a simple goto loop.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: factor out chained bio completion

2016-03-14T14:55:22+00:00

Factor common code between bio_chain_endio and bio_endio into a common
helper.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: don't unecessarily clobber bi_error for chained bios

2016-03-14T14:55:21+00:00

Only overwrite the parents bi_error if it was zero. That way a successful
bio completion doesn't reset the error pointer.

Reported-by: Brian Foster 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

bio: return EINTR if copying to user space got interrupted

2016-02-12T15:17:41+00:00

Commit 35dc248383bbab0a7203fca4d722875bc81ef091 introduced a check for
current->mm to see if we have a user space context and only copies data
if we do. Now if an IO gets interrupted by a signal data isn't copied
into user space any more (as we don't have a user space context) but
user space isn't notified about it.

This patch modifies the behaviour to return -EINTR from bio_uncopy_user()
to notify userland that a signal has interrupted the syscall, otherwise
it could lead to a situation where the caller may get a buffer with
no data returned.

This can be reproduced by issuing SG_IO ioctl()s in one thread while
constantly sending signals to it.

Fixes: 35dc248 [SCSI] sg: Fix user memory corruption when SG_IO is interrupted by a signal
Signed-off-by: Johannes Thumshirn 
Signed-off-by: Hannes Reinecke 
Cc: stable@vger.kernel.org # v.3.11+
Signed-off-by: Jens Axboe

kernel/fs: fix I/O wait not accounted for RW O_DSYNC

2016-02-09T16:27:01+00:00

 When a process is doing Random Write with O_DSYNC flag
 the I/O wait are not accounted in the kernel (get_cpu_iowait_time_us).
 This is preventing the governor or the cpufreq driver to account for
 I/O wait and thus use the right pstate

Signed-off-by: Stephane Gasparini 
Signed-off-by: Philippe Longepe 
Signed-off-by: Jens Axboe

bio: use offset_in_page macro

2015-11-24T22:24:25+00:00

Use offset_in_page macro instead of (addr & ~PAGE_MASK).

Signed-off-by: Geliang Tang 
Signed-off-by: Jens Axboe