Skip to content

K
Kernel

openeuler / Kernel
12 个月 前同步成功

通知 5
Star 0
Fork 0
K
Kernel

体验新版 GitCode，发现更多精彩内容 >>

切换分支/标签
  1. 30 10月, 2008 4 次提交
    • J
      Btrfs: nuke fs wide allocation mutex V2 · 25179201
      由 Josef Bacik 提交于 
      This patch removes the giant fs_info->alloc_mutex and replaces it with a bunch
of little locks.

There is now a pinned_mutex, which is used when messing with the pinned_extents
extent io tree, and the extent_ins_mutex which is used with the pending_del and
extent_ins extent io trees.

The locking for the extent tree stuff was inspired by a patch that Yan Zheng
wrote to fix a race condition, I cleaned it up some and changed the locking
around a little bit, but the idea remains the same.  Basically instead of
holding the extent_ins_mutex throughout the processing of an extent on the
extent_ins or pending_del trees, we just hold it while we're searching and when
we clear the bits on those trees, and lock the extent for the duration of the
operations on the extent.

Also to keep from getting hung up waiting to lock an extent, I've added a
try_lock_extent so if we cannot lock the extent, move on to the next one in the
tree and we'll come back to that one.  I have tested this heavily and it does
not appear to break anything.  This has to be applied on top of my
find_free_extent redo patch.

I tested this patch on top of Yan's space reblancing code and it worked fine.
The only thing that has changed since the last version is I pulled out all my
debugging stuff, apparently I forgot to run guilt refresh before I sent the
last patch out.  Thank you,
Signed-off-by: NJosef Bacik <jbacik@redhat.com>
      25179201
    • J
      Btrfs: fix enospc when there is plenty of space · 80eb234a
      由 Josef Bacik 提交于 
      So there is an odd case where we can possibly return -ENOSPC when there is in
fact space to be had.  It only happens with Metadata writes, and happens _very_
infrequently.  What has to happen is we have to allocate have allocated out of
the first logical byte on the disk, which would set last_alloc to
first_logical_byte(root, 0), so search_start == orig_search_start.  We then
need to allocate for normal metadata, so BTRFS_BLOCK_GROUP_METADATA |
BTRFS_BLOCK_GROUP_DUP.  We will do a block lookup for the given search_start,
block_group_bits() won't match and we'll go to choose another block group.
However because search_start matches orig_search_start we go to see if we can
allocate a chunk.

If we are in the situation that we cannot allocate a chunk, we fail and ENOSPC.
This is kind of a big flaw of the way find_free_extent works, as it along with
find_free_space loop through _all_ of the block groups, not just the ones that
we want to allocate out of.  This patch completely kills find_free_space and
rolls it into find_free_extent.  I've introduced a sort of state machine into
this, which will make it easier to get cache miss information out of the
allocator, and will work well with my locking changes.

The basic flow is this:  We have the variable loop which is 0, meaning we are
in the hint phase.  We lookup the block group for the hint, and lookup the
space_info for what we want to allocate out of.  If the block group we were
pointed at by the hint either isn't of the correct type, or just doesn't have
the space we need, we set head to space_info->block_groups, so we start at the
beginning of the block groups for this particular space info, and loop through.

This is also where we add the empty_cluster to total_needed.  At this point
loop is set to 1 and we just loop through all of the block groups for this
particular space_info looking for the space we need, just as find_free_space
would have done, except we only hit the block groups we want and not _all_ of
the block groups.  If we come full circle we see if we can allocate a chunk.
If we cannot of course we exit with -ENOSPC and we are good.  If not we start
over at space_info->block_groups and loop through again, with loop == 2.  If we
come full circle and haven't found what we need then we exit with -ENOSPC.
I've been running this for a couple of days now and it seems stable, and I
haven't yet hit a -ENOSPC when there was plenty of space left.

Also I've made a groups_sem to handle the group list for the space_info.  This
is part of my locking changes, but is relatively safe and seems better than
holding the space_info spinlock over that entire search time.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@redhat.com>
      80eb234a
    • Y
      Btrfs: Improve space balancing code · f82d02d9
      由 Yan Zheng 提交于 
      This patch improves the space balancing code to keep more sharing
of tree blocks. The only case that breaks sharing of tree blocks is
data extents get fragmented during balancing. The main changes in
this patch are:

Add a 'drop sub-tree' function. This solves the problem in old code
that BTRFS_HEADER_FLAG_WRITTEN check breaks sharing of tree block.

Remove relocation mapping tree. Relocation mappings are stored in
struct btrfs_ref_path and updated dynamically during walking up/down
the reference path. This reduces CPU usage and simplifies code.

This patch also fixes a bug. Root items for reloc trees should be
updated in btrfs_free_reloc_root.
Signed-off-by: NYan Zheng <zheng.yan@oracle.com>
      f82d02d9
    • C
      Btrfs: Add zlib compression support · c8b97818
      由 Chris Mason 提交于 
      This is a large change for adding compression on reading and writing,
both for inline and regular extents.  It does some fairly large
surgery to the writeback paths.

Compression is off by default and enabled by mount -o compress.  Even
when the -o compress mount option is not used, it is possible to read
compressed extents off the disk.

If compression for a given set of pages fails to make them smaller, the
file is flagged to avoid future compression attempts later.

* While finding delalloc extents, the pages are locked before being sent down
to the delalloc handler.  This allows the delalloc handler to do complex things
such as cleaning the pages, marking them writeback and starting IO on their
behalf.

* Inline extents are inserted at delalloc time now.  This allows us to compress
the data before inserting the inline extent, and it allows us to insert
an inline extent that spans multiple pages.

* All of the in-memory extent representations (extent_map.c, ordered-data.c etc)
are changed to record both an in-memory size and an on disk size, as well
as a flag for compression.

From a disk format point of view, the extent pointers in the file are changed
to record the on disk size of a given extent and some encoding flags.
Space in the disk format is allocated for compression encoding, as well
as encryption and a generic 'other' field.  Neither the encryption or the
'other' field are currently used.

In order to limit the amount of data read for a single random read in the
file, the size of a compressed extent is limited to 128k.  This is a
software only limit, the disk format supports u64 sized compressed extents.

In order to limit the ram consumed while processing extents, the uncompressed
size of a compressed extent is limited to 256k.  This is a software only limit
and will be subject to tuning later.

Checksumming is still done on compressed extents, and it is done on the
uncompressed version of the data.  This way additional encodings can be
layered on without having to figure out which encoding to checksum.

Compression happens at delalloc time, which is basically singled threaded because
it is usually done by a single pdflush thread.  This makes it tricky to
spread the compression load across all the cpus on the box.  We'll have to
look at parallel pdflush walks of dirty inodes at a later time.

Decompression is hooked into readpages and it does spread across CPUs nicely.
Signed-off-by: NChris Mason <chris.mason@oracle.com>
      c8b97818
  3. 16 10月, 2008 1 次提交
  5. 10 10月, 2008 9 次提交
  7. 09 10月, 2008 14 次提交
  9. 08 10月, 2008 6 次提交
    • D
      tcp: Fix tcp_hybla zero congestion window growth with small rho and large cwnd. · 9d2c27e1
      由 Daniele Lacamera 提交于 
      Because of rounding, in certain conditions, i.e. when in congestion
avoidance state rho is smaller than 1/128 of the current cwnd, TCP
Hybla congestion control starves and the cwnd is kept constant
forever.

This patch forces an increment by one segment after #send_cwnd calls
without increments(newreno behavior).
Signed-off-by: NDaniele Lacamera <root@danielinux.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      9d2c27e1
    • H
      net: Fix netdev_run_todo dead-lock · 58ec3b4d
      由 Herbert Xu 提交于 
      Benjamin Thery tracked down a bug that explains many instances
of the error

unregister_netdevice: waiting for %s to become free. Usage count = %d

It turns out that netdev_run_todo can dead-lock with itself if
a second instance of it is run in a thread that will then free
a reference to the device waited on by the first instance.

The problem is really quite silly.  We were trying to create
parallelism where none was required.  As netdev_run_todo always
follows a RTNL section, and that todo tasks can only be added
with the RTNL held, by definition you should only need to wait
for the very ones that you've added and be done with it.

There is no need for a second mutex or spinlock.

This is exactly what the following patch does.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      58ec3b4d
    • D
      Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/holtmann/bluetooth-2.6 · 742201e7
      由 David S. Miller 提交于
      742201e7
    • A
      tcp: Fix possible double-ack w/ user dma · 53240c20
      由 Ali Saidi 提交于 
      From: Ali Saidi <saidi@engin.umich.edu>

When TCP receive copy offload is enabled it's possible that
tcp_rcv_established() will cause two acks to be sent for a single
packet. In the case that a tcp_dma_early_copy() is successful,
copied_early is set to true which causes tcp_cleanup_rbuf() to be
called early which can send an ack. Further along in
tcp_rcv_established(), __tcp_ack_snd_check() is called and will
schedule a delayed ACK. If no packets are processed before the delayed
ack timer expires the packet will be acked twice.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      53240c20
    • P
      net: only invoke dev->change_rx_flags when device is UP · b6c40d68
      由 Patrick McHardy 提交于 
      Jesper Dangaard Brouer <hawk@comx.dk> reported a bug when setting a VLAN
device down that is in promiscous mode:

When the VLAN device is set down, the promiscous count on the real
device is decremented by one by vlan_dev_stop(). When removing the
promiscous flag from the VLAN device afterwards, the promiscous
count on the real device is decremented a second time by the
vlan_change_rx_flags() callback.

The root cause for this is that the ->change_rx_flags() callback is
invoked while the device is down. The synchronization is meant to mirror
the behaviour of the ->set_rx_mode callbacks, meaning the ->open function
is responsible for doing a full sync on open, the ->close() function is
responsible for doing full cleanup on ->stop() and ->change_rx_flags()
is meant to do incremental changes while the device is UP.

Only invoke ->change_rx_flags() while the device is UP to provide the
intended behaviour.
Tested-by: NJesper Dangaard Brouer <jdb@comx.dk>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      b6c40d68
    • M
      SLOB: fix bogus ksize calculation · 85ba94ba
      由 Matt Mackall 提交于 
      SLOB's ksize calculation was braindamaged and generally harmlessly
underreported the allocation size. But for very small buffers, it could
in fact overreport them, leading code depending on krealloc to overrun
the allocation and trample other data.
Signed-off-by: NMatt Mackall <mpm@selenic.com>
Tested-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      85ba94ba
  11. 07 10月, 2008 6 次提交