linux.git/fs/fs-writeback.c, branch v2.6.37

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable

2010-10-30T16:05:48+00:00

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (39 commits)
  Btrfs: deal with errors from updating the tree log
  Btrfs: allow subvol deletion by unprivileged user with -o user_subvol_rm_allowed
  Btrfs: make SNAP_DESTROY async
  Btrfs: add SNAP_CREATE_ASYNC ioctl
  Btrfs: add START_SYNC, WAIT_SYNC ioctls
  Btrfs: async transaction commit
  Btrfs: fix deadlock in btrfs_commit_transaction
  Btrfs: fix lockdep warning on clone ioctl
  Btrfs: fix clone ioctl where range is adjacent to extent
  Btrfs: fix delalloc checks in clone ioctl
  Btrfs: drop unused variable in block_alloc_rsv
  Btrfs: cleanup warnings from gcc 4.6 (nonbugs)
  Btrfs: Fix variables set but not read (bugs found by gcc 4.6)
  Btrfs: Use ERR_CAST helpers
  Btrfs: use memdup_user helpers
  Btrfs: fix raid code for removing missing drives
  Btrfs: Switch the extent buffer rbtree into a radix tree
  Btrfs: restructure try_release_extent_buffer()
  Btrfs: use the flusher threads for delalloc throttling
  Btrfs: tune the chunk allocation to 5% of the FS as metadata
  ...

Fix up trivial conflicts in fs/btrfs/super.c and fs/fs-writeback.c, and
remove use of INIT_RCU_HEAD in fs/btrfs/extent_io.c (that init macro was
useless and removed in commit 5e8067adfdba: "rcu head remove init")

fs-writeback.c: unify some common code

2010-10-30T15:55:52+00:00

The btrfs merge looks like hell, because it changes fs-writeback.c, and
the crazy code has this repeated "estimate number of dirty pages"
counting that involves three different helper functions.  And it's done
in two different places.

Just unify that whole calculation as a "get_nr_dirty_pages()" helper
function, and the merge result will look half-way decent.

Signed-off-by: Linus Torvalds

Add new functions for triggering inode writeback

2010-10-29T15:25:29+00:00

When btrfs is running low on metadata space, it needs to force delayed
allocation pages to disk.  It currently does this with a suboptimal walk
of a private list of inodes with delayed allocation, and it would be
much better if we used the generic flusher threads.

writeback_inodes_sb_if_idle would be ideal, but it waits for the flusher
thread to start IO on all the dirty pages in the FS before it returns.
This adds variants of writeback_inodes_sb* that allow the caller to
control how many pages get sent down.

Signed-off-by: Chris Mason

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6

2010-10-27T00:58:44+00:00

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (52 commits)
  split invalidate_inodes()
  fs: skip I_FREEING inodes in writeback_sb_inodes
  fs: fold invalidate_list into invalidate_inodes
  fs: do not drop inode_lock in dispose_list
  fs: inode split IO and LRU lists
  fs: switch bdev inode bdi's correctly
  fs: fix buffer invalidation in invalidate_list
  fsnotify: use dget_parent
  smbfs: use dget_parent
  exportfs: use dget_parent
  fs: use RCU read side protection in d_validate
  fs: clean up dentry lru modification
  fs: split __shrink_dcache_sb
  fs: improve DCACHE_REFERENCED usage
  fs: use percpu counter for nr_dentry and nr_dentry_unused
  fs: simplify __d_free
  fs: take dcache_lock inside __d_path
  fs: do not assign default i_ino in new_inode
  fs: introduce a per-cpu last_ino allocator
  new helper: ihold()
  ...

kernel: remove PF_FLUSHER

2010-10-26T23:52:15+00:00

PF_FLUSHER is only ever set, not tested, remove it.

Signed-off-by: Peter Zijlstra 
Cc: Jens Axboe 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fs/fs-writeback.c: restore lost comment

2010-10-26T23:52:10+00:00

I had to go back to a 2.6.20 tree to work out why we're adding a
number-of-inodes into a number-of-pages count.  Restore the lost comment.

Cc: Jens Axboe 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

writeback: remove the internal 5% low bound on dirty_ratio

2010-10-26T23:52:08+00:00

The dirty_ratio was silently limited in global_dirty_limits() to >= 5%.
This is not a user expected behavior.  And it's inconsistent with
calc_period_shift(), which uses the plain vm_dirty_ratio value.

Let's remove the internal bound.

At the same time, fix balance_dirty_pages() to work with the
dirty_thresh=0 case.  This allows applications to proceed when
dirty+writeback pages are all cleaned.

And ">" fits with the name "exceeded" better than ">=" does.  Neil thinks
it is an aesthetic improvement as well as a functional one :)

Signed-off-by: Wu Fengguang 
Cc: Jan Kara 
Proposed-by: Con Kolivas 
Acked-by: Peter Zijlstra 
Reviewed-by: Rik van Riel 
Reviewed-by: Neil Brown 
Reviewed-by: KOSAKI Motohiro 
Cc: Michael Rubin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fs: skip I_FREEING inodes in writeback_sb_inodes

2010-10-26T01:26:16+00:00

Skip I_FREEING inodes just like I_WILL_FREE and I_NEW when walking the
writeback lists.  Currenly this can't happen, but once we move from
inode_lock to more fine grained locking we can have an inode that's
still on the writeback lists but has I_FREEING set, and we absolutely
need to skip it here, just like we do for all other inode list walks.

Based on a patch from Dave Chinner.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Al Viro

fs: inode split IO and LRU lists

2010-10-26T01:26:15+00:00

The use of the same inode list structure (inode->i_list) for two
different list constructs with different lifecycles and purposes
makes it impossible to separate the locking of the different
operations. Therefore, to enable the separation of the locking of
the writeback and reclaim lists, split the inode->i_list into two
separate lists dedicated to their specific tracking functions.

Signed-off-by: Nick Piggin 
Signed-off-by: Dave Chinner 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Al Viro

fs: Implement lazy LRU updates for inodes

2010-10-26T01:26:09+00:00

Convert the inode LRU to use lazy updates to reduce lock and
cacheline traffic.  We avoid moving inodes around in the LRU list
during iget/iput operations so these frequent operations don't need
to access the LRUs. Instead, we defer the refcount checks to
reclaim-time and use a per-inode state flag, I_REFERENCED, to tell
reclaim that iget has touched the inode in the past. This means that
only reclaim should be touching the LRU with any frequency, hence
significantly reducing lock acquisitions and the amount contention
on LRU updates.

This also removes the inode_in_use list, which means we now only
have one list for tracking the inode LRU status. This makes it much
simpler to split out the LRU list operations under it's own lock.

Signed-off-by: Nick Piggin 
Signed-off-by: Dave Chinner 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Al Viro