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  1. 21 Oct, 2011 11 commits
    • Steven Whitehouse's avatar
      GFS2: Make resource groups "append only" during life of fs · 8339ee54
      Steven Whitehouse authored 
      Since we have ruled out supporting online filesystem shrink,
it is possible to make the resource group list append only
during the life of a super block. This gives several benefits:

Firstly, we only need to read new rindex elements as they are added
rather than needing to reread the whole rindex file each time one
element is added.

Secondly, the rindex glock can be held for much shorter periods of
time, and is completely removed from the fast path for allocations.
The lock is taken in shared mode only when updating the resource
groups when the first allocation occurs, and after a grow has
taken place.

Thirdly, this results in a reduction in code size, and everything
gets a lot simpler to understand in this area.
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
      8339ee54
    • Bob Peterson's avatar
      GFS2: Use rbtree for resource groups and clean up bitmap buffer ref count scheme · 7c9ca621
      Bob Peterson authored 
      Here is an update of Bob's original rbtree patch which, in addition, also
resolves the rather strange ref counting that was being done relating to
the bitmap blocks.

Originally we had a dual system for journaling resource groups. The metadata
blocks were journaled and also the rgrp itself was added to a list. The reason
for adding the rgrp to the list in the journal was so that the "repolish
clones" code could be run to update the free space, and potentially send any
discard requests when the log was flushed. This was done by comparing the
"cloned" bitmap with what had been written back on disk during the transaction
commit.

Due to this, there was a requirement to hang on to the rgrps' bitmap buffers
until the journal had been flushed. For that reason, there was a rather
complicated set up in the ->go_lock ->go_unlock functions for rgrps involving
both a mutex and a spinlock (the ->sd_rindex_spin) to maintain a reference
count on the buffers.

However, the journal maintains a reference count on the buffers anyway, since
they are being journaled as metadata buffers. So by moving the code which deals
with the post-journal accounting for bitmap blocks to the metadata journaling
code, we can entirely dispense with the rather strange buffer ref counting
scheme and also the requirement to journal the rgrps.

The net result of all this is that the ->sd_rindex_spin is left to do exactly
one job, and that is to look after the rbtree or rgrps.

This patch is designed to be a stepping stone towards using RCU for the rbtree
of resource groups, however the reduction in the number of uses of the
->sd_rindex_spin is likely to have benefits for multi-threaded workloads,
anyway.

The patch retains ->go_lock and ->go_unlock for rgrps, however these maybe also
be removed in future in favour of calling the functions directly where required
in the code. That will allow locking of resource groups without needing to
actually read them in - something that could be useful in speeding up statfs.

In the mean time though it is valid to dereference ->bi_bh only when the rgrp
is locked. This is basically the same rule as before, modulo the references not
being valid until the following journal flush.
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
Cc: Benjamin Marzinski <bmarzins@redhat.com>
      7c9ca621
    • Steven Whitehouse's avatar
      GFS2: Fix lseek after SEEK_DATA, SEEK_HOLE have been added · 9453615a
      Steven Whitehouse authored 
      We need to take the inode's glock whenever the inode's size
is referenced, otherwise it might not be uptodate. Even
though generic_file_llseek_unlocked() doesn't implement
SEEK_DATA, SEEK_HOLE directly, it does reference the inode's
size in those cases, so we need to add them to the list
of origins which need the glock.
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
      9453615a
    • Steven Whitehouse's avatar
      GFS2: Clean up gfs2_create · 9a63edd1
      Steven Whitehouse authored 
      If we pass through knowledge of whether the creation is intended to be
exclusive or not, then we can deal with that in gfs2_create_inode
and remove one set of locking. Also this removes the loop in
gfs2_create and simplifies the code a bit.
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
      9a63edd1
    • Steven Whitehouse's avatar
      GFS2: Use ->dirty_inode() · ab9bbda0
      Steven Whitehouse authored 
      The aim of this patch is to use the newly enhanced ->dirty_inode()
super block operation to deal with atime updates, rather than
piggy backing that code into ->write_inode() as is currently
done.

The net result is a simplification of the code in various places
and a reduction of the number of gfs2_dinode_out() calls since
this is now implied by ->dirty_inode().

Some of the mark_inode_dirty() calls have been moved under glocks
in order to take advantage of then being able to avoid locking in
->dirty_inode() when we already have suitable locks.

One consequence is that generic_write_end() now correctly deals
with file size updates, so that we do not need a separate check
for that afterwards. This also, indirectly, means that fdatasync
should work correctly on GFS2 - the current code always syncs the
metadata whether it needs to or not.

Has survived testing with postmark (with and without atime) and
also fsx.
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
      ab9bbda0
    • Steven Whitehouse's avatar
      GFS2: Fix bug trap and journaled data fsync · f1818529
      Steven Whitehouse authored 
      Journaled data requires that a complete flush of all dirty data for
the file is done, in order that the ail flush which comes after
will succeed.

Also the recently enhanced bug trap can trigger falsely in case
an ail flush from fsync races with a page read. This updates the
bug trap such that it will ignore buffers which are locked and
only trigger on dirty and/or pinned buffers when the ail flush
is run from fsync. The original bug trap is retained when ail
flush is run from ->go_sync()
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
      f1818529
    • Steven Whitehouse's avatar
      GFS2: Fix inode allocation error path · 40ac218f
      Steven Whitehouse authored 
      If we have got far enough through the inode allocation code
path that an inode has already been allocated, then we must
call iput to dispose of it, if an error occurs during a
later part of the process. This will always be the final iput
since there will be no other references to the inode.

Unlike when the inode has been unlinked, its block state will
be GFS2_BLKST_INODE rather than GFS2_BLKST_UNLINKED so we need
to skip the test in ->evict_inode() for this one case in order
to ensure that it will be deallocated correctly. This patch adds
a new flag in order to ensure that this will happen correctly.
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
      40ac218f
    • Steven Whitehouse's avatar
      GFS2: Make atime checks more efficient · 1d4ec642
      Steven Whitehouse authored 
      We do not need to start a transaction unless the atime
check has proved positive. Also if we are going to flush
the complete ail list anyway, we might as well skip the
writeback for this specific inode's metadata, since that
will be done as part of the ail writeback process in an
order offering potentially more efficient I/O.
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
      1d4ec642
    • Steven Whitehouse's avatar
      GFS2: Fix bug-trap in ail flush code · 75549186
      Steven Whitehouse authored 
      The assert was being tested under the wrong lock, a
legacy of the original code. Also, if it does trigger,
the resulting information was not always a lot of help.

This moves the patch under the correct lock and also
prints out more useful information in tacking down the
source of the problem.
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
      75549186
    • Steven Whitehouse's avatar
      GFS2: Split data write & wait in fsync · 2f0264d5
      Steven Whitehouse authored 
      Now that the data writing is part of fsync proper, we can split
the waiting part out and do it later on. This reduces the
number of waits that we do during fsync on average.

There is also no need to take the i_mutex unless we are flushing
metadata to disk, so we can move that to within the metadata
flushing code.
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
      2f0264d5
    • Steven Whitehouse's avatar
      GFS2: Clean up dir hash table reading · 4c28d338
      Steven Whitehouse authored 
      Since there is now only a single caller to gfs2_dir_read_data()
and it has a number of constant arguments, we can factor
those out. Also some tests relating to the inode size were
being done twice.
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
      4c28d338
  3. 20 Oct, 2011 3 commits
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc · fd11e153
      Linus Torvalds authored 
      * git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc: Add alignment flag to PCI expansion resources
  sparc: Avoid calling sigprocmask()
  sparc: Use set_current_blocked()
  sparc32,leon: SRMMU MMU Table probe fix
      fd11e153
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net · 505f48b5
      Linus Torvalds authored 
      * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  fib_rules: fix unresolved_rules counting
  r8169: fix wrong eee setting for rlt8111evl
  r8169: fix driver shutdown WoL regression.
  ehea: Change maintainer to me
  pptp: pptp_rcv_core() misses pskb_may_pull() call
  tproxy: copy transparent flag when creating a time wait
  pptp: fix skb leak in pptp_xmit()
  bonding: use local function pointer of bond->recv_probe in bond_handle_frame
  smsc911x: Add support for SMSC LAN89218
  tg3: negate USE_PHYLIB flag check
  netconsole: enable netconsole can make net_device refcnt incorrent
  bluetooth: Properly clone LSM attributes to newly created child connections
  l2tp: fix a potential skb leak in l2tp_xmit_skb()
  bridge: fix hang on removal of bridge via netlink
  x25: Prevent skb overreads when checking call user data
  x25: Handle undersized/fragmented skbs
  x25: Validate incoming call user data lengths
  udplite: fast-path computation of checksum coverage
  IPVS netns shutdown/startup dead-lock
  netfilter: nf_conntrack: fix event flooding in GRE protocol tracker
      505f48b5
    • Hugh Dickins's avatar
      mm: fix race between mremap and removing migration entry · 486cf46f
      Hugh Dickins authored 
      I don't usually pay much attention to the stale "? " addresses in
stack backtraces, but this lucky report from Pawel Sikora hints that
mremap's move_ptes() has inadequate locking against page migration.

 3.0 BUG_ON(!PageLocked(p)) in migration_entry_to_page():
 kernel BUG at include/linux/swapops.h:105!
 RIP: 0010:[<ffffffff81127b76>]  [<ffffffff81127b76>]
                       migration_entry_wait+0x156/0x160
  [<ffffffff811016a1>] handle_pte_fault+0xae1/0xaf0
  [<ffffffff810feee2>] ? __pte_alloc+0x42/0x120
  [<ffffffff8112c26b>] ? do_huge_pmd_anonymous_page+0xab/0x310
  [<ffffffff81102a31>] handle_mm_fault+0x181/0x310
  [<ffffffff81106097>] ? vma_adjust+0x537/0x570
  [<ffffffff81424bed>] do_page_fault+0x11d/0x4e0
  [<ffffffff81109a05>] ? do_mremap+0x2d5/0x570
  [<ffffffff81421d5f>] page_fault+0x1f/0x30

mremap's down_write of mmap_sem, together with i_mmap_mutex or lock,
and pagetable locks, were good enough before page migration (with its
requirement that every migration entry be found) came in, and enough
while migration always held mmap_sem; but not enough nowadays, when
there's memory hotremove and compaction.

The danger is that move_ptes() lets a migration entry dodge around
behind remove_migration_pte()'s back, so it's in the old location when
looking at the new, then in the new location when looking at the old.

Either mremap's move_ptes() must additionally take anon_vma lock(), or
migration's remove_migration_pte() must stop peeking for is_swap_entry()
before it takes pagetable lock.

Consensus chooses the latter: we prefer to add overhead to migration
than to mremapping, which gets used by JVMs and by exec stack setup.
Reported-and-tested-by: default avatarPaweł Sikora <pluto@agmk.net>
Signed-off-by: default avatarHugh Dickins <hughd@google.com>
Acked-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
Acked-by: default avatarMel Gorman <mgorman@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      486cf46f
  5. 19 Oct, 2011 19 commits
  7. 18 Oct, 2011 6 commits
  9. 17 Oct, 2011 1 commit
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