linux.git/fs/logfs, branch v2.6.38

Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block

2011-01-13T18:45:01+00:00

* 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block: (43 commits)
  block: ensure that completion error gets properly traced
  blktrace: add missing probe argument to block_bio_complete
  block cfq: don't use atomic_t for cfq_group
  block cfq: don't use atomic_t for cfq_queue
  block: trace event block fix unassigned field
  block: add internal hd part table references
  block: fix accounting bug on cross partition merges
  kref: add kref_test_and_get
  bio-integrity: mark kintegrityd_wq highpri and CPU intensive
  block: make kblockd_workqueue smarter
  Revert "sd: implement sd_check_events()"
  block: Clean up exit_io_context() source code.
  Fix compile warnings due to missing removal of a 'ret' variable
  fs/block: type signature of major_to_index(int) to major_to_index(unsigned)
  block: convert !IS_ERR(p) && p to !IS_ERR_NOR_NULL(p)
  cfq-iosched: don't check cfqg in choose_service_tree()
  fs/splice: Pull buf->ops->confirm() from splice_from_pipe actors
  cdrom: export cdrom_check_events()
  sd: implement sd_check_events()
  sr: implement sr_check_events()
  ...

fs: provide rcu-walk aware permission i_ops

2011-01-07T06:50:29+00:00

Signed-off-by: Nick Piggin

fs: icache RCU free inodes

2011-01-07T06:50:26+00:00

RCU free the struct inode. This will allow:

- Subsequent store-free path walking patch. The inode must be consulted for
  permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
  to take i_lock no longer need to take sb_inode_list_lock to walk the list in
  the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
  page lock to follow page->mapping.

The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.

In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.

The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.

Signed-off-by: Nick Piggin

logfs: fix "Kernel BUG at readwrite.c:1193"

2010-12-23T03:43:33+00:00

This happens when __logfs_create() tries to write a new inode to the disk
which is full.

__logfs_create() associates the transaction pointer with inode.  During
the logfs_write_inode() function call chain this transaction pointer is
moved from inode to page->private using function move_inode_to_page
(do_write_inode() -> inode_to_page() -> move_inode_to_page)

When the write inode fails, the transaction is aborted and iput is called
on the failed inode.  During delete_inode the same transaction pointer
associated with the page is getting used.  Thus causing kernel BUG.

The patch checks for error in write_inode() and restores the page->private
to NULL.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=20162

Signed-off-by: Prasad Joshi 
Cc: Joern Engel 
Cc: Florian Mickler 
Cc: "Rafael J. Wysocki" 
Cc: Maciej Rutecki 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

logfs: fix deadlock in logfs_get_wblocks, hold and wait on super->s_write_mutex

2010-12-23T03:43:33+00:00

do_logfs_journal_wl_pass() should use GFP_NOFS for memory allocation GC
code calls btree_insert32 with GFP_KERNEL while holding a mutex
super->s_write_mutex.

The same mutex is used in address_space_operations->writepage(), and a
call to writepage() could be triggered as a result of memory allocation
in btree_insert32, causing a deadlock.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=20342

Signed-off-by: Prasad Joshi 
Cc: Joern Engel 
Cc: Florian Mickler 
Cc: "Rafael J. Wysocki" 
Cc: Maciej Rutecki 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

block: clean up blkdev_get() wrappers and their users

2010-11-13T10:55:18+00:00

After recent blkdev_get() modifications, open_by_devnum() and
open_bdev_exclusive() are simple wrappers around blkdev_get().
Replace them with blkdev_get_by_dev() and blkdev_get_by_path().

blkdev_get_by_dev() is identical to open_by_devnum().
blkdev_get_by_path() is slightly different in that it doesn't
automatically add %FMODE_EXCL to @mode.

All users are converted.  Most conversions are mechanical and don't
introduce any behavior difference.  There are several exceptions.

* btrfs now sets FMODE_EXCL in btrfs_device->mode, so there's no
  reason to OR it explicitly on blkdev_put().

* gfs2, nilfs2 and the generic mount_bdev() now set FMODE_EXCL in
  sb->s_mode.

* With the above changes, sb->s_mode now always should contain
  FMODE_EXCL.  WARN_ON_ONCE() added to kill_block_super() to detect
  errors.

The new blkdev_get_*() functions are with proper docbook comments.
While at it, add function description to blkdev_get() too.

Signed-off-by: Tejun Heo 
Cc: Philipp Reisner 
Cc: Neil Brown 
Cc: Mike Snitzer 
Cc: Joern Engel 
Cc: Chris Mason 
Cc: Jan Kara 
Cc: "Theodore Ts'o" 
Cc: KONISHI Ryusuke 
Cc: reiserfs-devel@vger.kernel.org
Cc: xfs-masters@oss.sgi.com
Cc: Alexander Viro

block: make blkdev_get/put() handle exclusive access

2010-11-13T10:55:17+00:00

Over time, block layer has accumulated a set of APIs dealing with bdev
open, close, claim and release.

* blkdev_get/put() are the primary open and close functions.

* bd_claim/release() deal with exclusive open.

* open/close_bdev_exclusive() are combination of open and claim and
  the other way around, respectively.

* bd_link/unlink_disk_holder() to create and remove holder/slave
  symlinks.

* open_by_devnum() wraps bdget() + blkdev_get().

The interface is a bit confusing and the decoupling of open and claim
makes it impossible to properly guarantee exclusive access as
in-kernel open + claim sequence can disturb the existing exclusive
open even before the block layer knows the current open if for another
exclusive access.  Reorganize the interface such that,

* blkdev_get() is extended to include exclusive access management.
  @holder argument is added and, if is @FMODE_EXCL specified, it will
  gain exclusive access atomically w.r.t. other exclusive accesses.

* blkdev_put() is similarly extended.  It now takes @mode argument and
  if @FMODE_EXCL is set, it releases an exclusive access.  Also, when
  the last exclusive claim is released, the holder/slave symlinks are
  removed automatically.

* bd_claim/release() and close_bdev_exclusive() are no longer
  necessary and either made static or removed.

* bd_link_disk_holder() remains the same but bd_unlink_disk_holder()
  is no longer necessary and removed.

* open_bdev_exclusive() becomes a simple wrapper around lookup_bdev()
  and blkdev_get().  It also has an unexpected extra bdev_read_only()
  test which probably should be moved into blkdev_get().

* open_by_devnum() is modified to take @holder argument and pass it to
  blkdev_get().

Most of bdev open/close operations are unified into blkdev_get/put()
and most exclusive accesses are tested atomically at the open time (as
it should).  This cleans up code and removes some, both valid and
invalid, but unnecessary all the same, corner cases.

open_bdev_exclusive() and open_by_devnum() can use further cleanup -
rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop
special features.  Well, let's leave them for another day.

Most conversions are straight-forward.  drbd conversion is a bit more
involved as there was some reordering, but the logic should stay the
same.

Signed-off-by: Tejun Heo 
Acked-by: Neil Brown 
Acked-by: Ryusuke Konishi 
Acked-by: Mike Snitzer 
Acked-by: Philipp Reisner 
Cc: Peter Osterlund 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: Jan Kara 
Cc: Andrew Morton 
Cc: Andreas Dilger 
Cc: "Theodore Ts'o" 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Alex Elder 
Cc: Christoph Hellwig 
Cc: dm-devel@redhat.com
Cc: drbd-dev@lists.linbit.com
Cc: Leo Chen 
Cc: Scott Branden 
Cc: Chris Mason 
Cc: Steven Whitehouse 
Cc: Dave Kleikamp 
Cc: Joern Engel 
Cc: reiserfs-devel@vger.kernel.org
Cc: Alexander Viro

fs: logfs: Fix up MTD=y build.

2010-11-01T20:34:56+00:00

Commit 7d945a3aa760 ("logfs get_sb, part 3") broke the logfs build when
CONFIG_MTD is set due to a mangled logfs_get_sb_mtd() definition.

Signed-off-by: Paul Mundt 
Signed-off-by: Linus Torvalds

switch logfs to ->mount()

2010-10-29T08:16:51+00:00

Signed-off-by: Al Viro

logfs: fix a leak in get_sb

2010-10-29T08:16:48+00:00

a) switch ->put_device() to logfs_super *
b) actually call it on early failures in logfs_get_sb_device()

Signed-off-by: Al Viro