1. 11 9月, 2011 2 次提交
    • M
      Btrfs: fix unclosed transaction handle in btrfs_cont_expand · 5b397377
      Miao Xie 提交于
      The function - btrfs_cont_expand() forgot to close the transaction handle before
      it jump out the while loop. Fix it.
      Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
      Signed-off-by: NChris Mason <chris.mason@oracle.com>
      5b397377
    • S
      btrfs: fix warning in iput for bad-inode · e0b6d65b
      Sergei Trofimovich 提交于
      iput() shouldn't be called for inodes in I_NEW state.
      We need to mark inode as constructed first.
      
      WARNING: at fs/inode.c:1309 iput+0x20b/0x210()
      Call Trace:
       [<ffffffff8103e7ba>] warn_slowpath_common+0x7a/0xb0
       [<ffffffff8103e805>] warn_slowpath_null+0x15/0x20
       [<ffffffff810eaf0b>] iput+0x20b/0x210
       [<ffffffff811b96fb>] btrfs_iget+0x1eb/0x4a0
       [<ffffffff811c3ad6>] btrfs_run_defrag_inodes+0x136/0x210
       [<ffffffff811ad55f>] cleaner_kthread+0x17f/0x1a0
       [<ffffffff81035b7d>] ? sub_preempt_count+0x9d/0xd0
       [<ffffffff811ad3e0>] ? transaction_kthread+0x280/0x280
       [<ffffffff8105af86>] kthread+0x96/0xa0
       [<ffffffff814336d4>] kernel_thread_helper+0x4/0x10
       [<ffffffff8105aef0>] ? kthread_worker_fn+0x190/0x190
       [<ffffffff814336d0>] ? gs_change+0xb/0xb
      Signed-off-by: NSergei Trofimovich <slyfox@gentoo.org>
      CC: Konstantin Khlebnikov <khlebnikov@openvz.org>
      Tested-by: NDavid Sterba <dsterba@suse.cz>
      CC: Josef Bacik <josef@redhat.com>
      CC: Chris Mason <chris.mason@oracle.com>
      Signed-off-by: NChris Mason <chris.mason@oracle.com>
      e0b6d65b
  2. 02 8月, 2011 3 次提交
  3. 28 7月, 2011 4 次提交
    • C
      Btrfs: use the commit_root for reading free_space_inode crcs · 2cf8572d
      Chris Mason 提交于
      Now that we are using regular file crcs for the free space cache,
      we can deadlock if we try to read the free_space_inode while we are
      updating the crc tree.
      
      This commit fixes things by using the commit_root to read the crcs.  This is
      safe because we the free space cache file would already be loaded if
      that block group had been changed in the current transaction.
      Signed-off-by: NChris Mason <chris.mason@oracle.com>
      2cf8572d
    • C
      Btrfs: stop using highmem for extent_buffers · a6591715
      Chris Mason 提交于
      The extent_buffers have a very complex interface where
      we use HIGHMEM for metadata and try to cache a kmap mapping
      to access the memory.
      
      The next commit adds reader/writer locks, and concurrent use
      of this kmap cache would make it even more complex.
      
      This commit drops the ability to use HIGHMEM with extent buffers,
      and rips out all of the related code.
      Signed-off-by: NChris Mason <chris.mason@oracle.com>
      a6591715
    • J
      Btrfs: fix enospc problems with delalloc · 9e0baf60
      Josef Bacik 提交于
      So I had this brilliant idea to use atomic counters for outstanding and reserved
      extents, but this turned out to be a bad idea.  Consider this where we have 1
      outstanding extent and 1 reserved extent
      
      Reserver				Releaser
      					atomic_dec(outstanding) now 0
      atomic_read(outstanding)+1 get 1
      atomic_read(reserved) get 1
      don't actually reserve anything because
      they are the same
      					atomic_cmpxchg(reserved, 1, 0)
      atomic_inc(outstanding)
      atomic_add(0, reserved)
      					free reserved space for 1 extent
      
      Then the reserver now has no actual space reserved for it, and when it goes to
      finish the ordered IO it won't have enough space to do it's allocation and you
      get those lovely warnings.
      Signed-off-by: NJosef Bacik <josef@redhat.com>
      Signed-off-by: NChris Mason <chris.mason@oracle.com>
      9e0baf60
    • J
      Btrfs: use find_or_create_page instead of grab_cache_page · a94733d0
      Josef Bacik 提交于
      grab_cache_page will use mapping_gfp_mask(), which for all inodes is set to
      GFP_HIGHUSER_MOVABLE.  So instead use find_or_create_page in all cases where we
      need GFP_NOFS so we don't deadlock.  Thanks,
      Signed-off-by: NJosef Bacik <josef@redhat.com>
      a94733d0
  4. 15 7月, 2011 3 次提交
    • M
      btrfs: Don't BUG_ON alloc_path errors in btrfs_read_locked_inode · 1748f843
      Mark Fasheh 提交于
      btrfs_iget() also needed an update so that errors from btrfs_locked_inode()
      are caught and bubbled back up.
      Signed-off-by: NMark Fasheh <mfasheh@suse.com>
      1748f843
    • M
      btrfs: Don't BUG_ON alloc_path errors in btrfs_truncate_inode_items · 0eb0e19c
      Mark Fasheh 提交于
      I moved the path allocation up a few lines to the top of the function so
      that we couldn't get into the state where we've dropped delayed items and
      the extent cache but fail due to -ENOMEM.
      Signed-off-by: NMark Fasheh <mfasheh@suse.com>
      0eb0e19c
    • M
      btrfs: don't BUG_ON btrfs_alloc_path() errors · d8926bb3
      Mark Fasheh 提交于
      This patch fixes many callers of btrfs_alloc_path() which BUG_ON allocation
      failure. All the sites that are fixed in this patch were checked by me to
      be fairly trivial to fix because of at least one of two criteria:
      
       - Callers of the function catch errors from it already so bubbling the
         error up will be handled.
       - Callers of the function might BUG_ON any nonzero return code in which
         case there is no behavior changed (but we still got to remove a BUG_ON)
      
      The following functions were updated:
      
      btrfs_lookup_extent, alloc_reserved_tree_block, btrfs_remove_block_group,
      btrfs_lookup_csums_range, btrfs_csum_file_blocks, btrfs_mark_extent_written,
      btrfs_inode_by_name, btrfs_new_inode, btrfs_symlink,
      insert_reserved_file_extent, and run_delalloc_nocow
      Signed-off-by: NMark Fasheh <mfasheh@suse.com>
      d8926bb3
  5. 07 7月, 2011 1 次提交
    • M
      btrfs: fix oops when doing space balance · 149e2d76
      Miao Xie 提交于
      We need to make sure the data relocation inode doesn't go through
      the delayed metadata updates, otherwise we get an oops during balance:
      
      kernel BUG at fs/btrfs/relocation.c:4303!
      [SNIP]
      Call Trace:
       [<ffffffffa03143fd>] ? update_ref_for_cow+0x22d/0x330 [btrfs]
       [<ffffffffa0314951>] __btrfs_cow_block+0x451/0x5e0 [btrfs]
       [<ffffffffa031355d>] ? read_block_for_search+0x14d/0x4d0 [btrfs]
       [<ffffffffa0314beb>] btrfs_cow_block+0x10b/0x240 [btrfs]
       [<ffffffffa031acae>] btrfs_search_slot+0x49e/0x7a0 [btrfs]
       [<ffffffffa032d8af>] btrfs_lookup_inode+0x2f/0xa0 [btrfs]
       [<ffffffff8147bf0e>] ? mutex_lock+0x1e/0x50
       [<ffffffffa0380cf1>] btrfs_update_delayed_inode+0x71/0x160 [btrfs]
       [<ffffffffa037ff27>] ? __btrfs_release_delayed_node+0x67/0x190 [btrfs]
       [<ffffffffa0381cf8>] btrfs_run_delayed_items+0xe8/0x120 [btrfs]
       [<ffffffffa03365e0>] btrfs_commit_transaction+0x250/0x850 [btrfs]
       [<ffffffff810f91d9>] ? find_get_pages+0x39/0x130
       [<ffffffffa0336cd5>] ? join_transaction+0x25/0x250 [btrfs]
       [<ffffffff81081de0>] ? wake_up_bit+0x40/0x40
       [<ffffffffa03785fa>] prepare_to_relocate+0xda/0xf0 [btrfs]
       [<ffffffffa037f2bb>] relocate_block_group+0x4b/0x620 [btrfs]
       [<ffffffffa0334cf5>] ? btrfs_clean_old_snapshots+0x35/0x150 [btrfs]
       [<ffffffffa037fa43>] btrfs_relocate_block_group+0x1b3/0x2e0 [btrfs]
       [<ffffffffa0368ec0>] ? btrfs_tree_unlock+0x50/0x50 [btrfs]
       [<ffffffffa035e39b>] btrfs_relocate_chunk+0x8b/0x670 [btrfs]
       [<ffffffffa031303d>] ? btrfs_set_path_blocking+0x3d/0x50 [btrfs]
       [<ffffffffa03577d8>] ? read_extent_buffer+0xd8/0x1d0 [btrfs]
       [<ffffffffa031bea1>] ? btrfs_previous_item+0xb1/0x150 [btrfs]
       [<ffffffffa03577d8>] ? read_extent_buffer+0xd8/0x1d0 [btrfs]
       [<ffffffffa035f5aa>] btrfs_balance+0x21a/0x2b0 [btrfs]
       [<ffffffffa0368898>] btrfs_ioctl+0x798/0xd20 [btrfs]
       [<ffffffff8111e358>] ? handle_mm_fault+0x148/0x270
       [<ffffffff814809e8>] ? do_page_fault+0x1d8/0x4b0
       [<ffffffff81160d6a>] do_vfs_ioctl+0x9a/0x540
       [<ffffffff811612b1>] sys_ioctl+0xa1/0xb0
       [<ffffffff81484ec2>] system_call_fastpath+0x16/0x1b
      [SNIP]
      RIP  [<ffffffffa037c1cc>] btrfs_reloc_cow_block+0x22c/0x270 [btrfs]
      Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
      Signed-off-by: NChris Mason <chris.mason@oracle.com>
      149e2d76
  6. 27 6月, 2011 1 次提交
    • M
      btrfs: fix inconsonant inode information · 2f7e33d4
      Miao Xie 提交于
      When iputting the inode, We may leave the delayed nodes if they have some
      delayed items that have not been dealt with. So when the inode is read again,
      we must look up the relative delayed node, and use the information in it to
      initialize the inode. Or we will get inconsonant inode information, it may
      cause that the same directory index number is allocated again, and hit the
      following oops:
      
      [ 5447.554187] err add delayed dir index item(name: pglog_0.965_0) into the
      insertion tree of the delayed node(root id: 262, inode id: 258, errno: -17)
      [ 5447.569766] ------------[ cut here ]------------
      [ 5447.575361] kernel BUG at fs/btrfs/delayed-inode.c:1301!
      [SNIP]
      [ 5447.790721] Call Trace:
      [ 5447.793191]  [<ffffffffa0641c4e>] btrfs_insert_dir_item+0x189/0x1bb [btrfs]
      [ 5447.800156]  [<ffffffffa0651a45>] btrfs_add_link+0x12b/0x191 [btrfs]
      [ 5447.806517]  [<ffffffffa0651adc>] btrfs_add_nondir+0x31/0x58 [btrfs]
      [ 5447.812876]  [<ffffffffa0651d6a>] btrfs_create+0xf9/0x197 [btrfs]
      [ 5447.818961]  [<ffffffff8111f840>] vfs_create+0x72/0x92
      [ 5447.824090]  [<ffffffff8111fa8c>] do_last+0x22c/0x40b
      [ 5447.829133]  [<ffffffff8112076a>] path_openat+0xc0/0x2ef
      [ 5447.834438]  [<ffffffff810c58e2>] ? __perf_event_task_sched_out+0x24/0x44
      [ 5447.841216]  [<ffffffff8103ecdd>] ? perf_event_task_sched_out+0x59/0x67
      [ 5447.847846]  [<ffffffff81121a79>] do_filp_open+0x3d/0x87
      [ 5447.853156]  [<ffffffff811e126c>] ? strncpy_from_user+0x43/0x4d
      [ 5447.859072]  [<ffffffff8111f1f5>] ? getname_flags+0x2e/0x80
      [ 5447.864636]  [<ffffffff8111f179>] ? do_getname+0x14b/0x173
      [ 5447.870112]  [<ffffffff8111f1b7>] ? audit_getname+0x16/0x26
      [ 5447.875682]  [<ffffffff8112b1ab>] ? spin_lock+0xe/0x10
      [ 5447.880882]  [<ffffffff81112d39>] do_sys_open+0x69/0xae
      [ 5447.886153]  [<ffffffff81112db1>] sys_open+0x20/0x22
      [ 5447.891114]  [<ffffffff813b9aab>] system_call_fastpath+0x16/0x1b
      
      Fix it by reusing the old delayed node.
      Reported-by: NJim Schutt <jaschut@sandia.gov>
      Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
      Tested-by: NJim Schutt <jaschut@sandia.gov>
      Signed-off-by: NChris Mason <chris.mason@oracle.com>
      2f7e33d4
  7. 25 6月, 2011 1 次提交
  8. 16 6月, 2011 1 次提交
  9. 11 6月, 2011 2 次提交
  10. 04 6月, 2011 1 次提交
  11. 27 5月, 2011 2 次提交
    • C
      fs: pass exact type of data dirties to ->dirty_inode · aa385729
      Christoph Hellwig 提交于
      Tell the filesystem if we just updated timestamp (I_DIRTY_SYNC) or
      anything else, so that the filesystem can track internally if it
      needs to push out a transaction for fdatasync or not.
      
      This is just the prototype change with no user for it yet.  I plan
      to push large XFS changes for the next merge window, and getting
      this trivial infrastructure in this window would help a lot to avoid
      tree interdependencies.
      
      Also remove incorrect comments that ->dirty_inode can't block.  That
      has been changed a long time ago, and many implementations rely on it.
      Signed-off-by: NChristoph Hellwig <hch@lst.de>
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      aa385729
    • C
      Btrfs: add mount -o auto_defrag · 4cb5300b
      Chris Mason 提交于
      This will detect small random writes into files and
      queue the up for an auto defrag process.  It isn't well suited to
      database workloads yet, but works for smaller files such as rpm, sqlite
      or bdb databases.
      Signed-off-by: NChris Mason <chris.mason@oracle.com>
      4cb5300b
  12. 26 5月, 2011 3 次提交
  13. 24 5月, 2011 9 次提交
    • J
      fs/btrfs: Add missing btrfs_free_path · b0839166
      Julia Lawall 提交于
      Btrfs_alloc_path should be matched with btrfs_free_path in error-handling code.
      
      A simplified version of the semantic match that finds this problem is as
      follows: (http://coccinelle.lip6.fr/)
      
      // <smpl>
      @r exists@
      local idexpression struct btrfs_path * x;
      expression ra,rb;
      position p1,p2;
      @@
      
      x = btrfs_alloc_path@p1(...)
      ...  when != btrfs_free_path(x,...)
           when != if (...) { ... btrfs_free_path(x,...) ...}
           when != x = ra
      if(...) { ... when != x = rb
           when forall
           when != btrfs_free_path(x,...)
       \(return <+...x...+>; \| return@p2...; \) }
      
      @script:python@
      p1 << r.p1;
      p2 << r.p2;
      @@
      
      cocci.print_main("alloc",p1)
      cocci.print_secs("return",p2)
      // </smpl>
      Signed-off-by: NJulia Lawall <julia@diku.dk>
      Signed-off-by: NChris Mason <chris.mason@oracle.com>
      b0839166
    • T
      Btrfs: BUG_ON is deleted from the caller of btrfs_truncate_item & btrfs_extend_item · 1cd30799
      Tsutomu Itoh 提交于
      Currently, btrfs_truncate_item and btrfs_extend_item returns only 0.
      So, the check by BUG_ON in the caller is unnecessary.
      Signed-off-by: NTsutomu Itoh <t-itoh@jp.fujitsu.com>
      Signed-off-by: NChris Mason <chris.mason@oracle.com>
      1cd30799
    • S
      27160b6b
    • J
      Btrfs: leave spinning on lookup and map the leaf · d90c7321
      Josef Bacik 提交于
      On lookup we only want to read the inode item, so leave the path spinning.  Also
      we're just wholesale reading the leaf off, so map the leaf so we don't do a
      bunch of kmap/kunmaps.  Thanks,
      Signed-off-by: NJosef Bacik <josef@redhat.com>
      d90c7321
    • J
      Btrfs: don't always do readahead · 026fd317
      Josef Bacik 提交于
      Our readahead is sort of sloppy, and really isn't always needed.  For example if
      ls is doing a stating ls (which is the default) it's going to stat in non-disk
      order, so if say you have a directory with a stupid amount of files, readahead
      is going to do nothing but waste time in the case of doing the stat.  Taking the
      unconditional readahead out made my test go from 57 minutes to 36 minutes.  This
      means that everywhere we do loop through the tree we want to make sure we do set
      path->reada properly, so I went through and found all of the places where we
      loop through the path and set reada to 1.  Thanks,
      Signed-off-by: NJosef Bacik <josef@redhat.com>
      026fd317
    • J
      Btrfs: kill BTRFS_I(inode)->block_group · d82a6f1d
      Josef Bacik 提交于
      Originally this was going to be used as a way to give hints to the allocator,
      but frankly we can get much better hints elsewhere and it's not even used at all
      for anything usefull.  In addition to be completely useless, when we initialize
      an inode we try and find a freeish block group to set as the inodes block group,
      and with a completely full 40gb fs this takes _forever_, so I imagine with say
      1tb fs this is just unbearable.  So just axe the thing altoghether, we don't
      need it and it saves us 8 bytes in the inode and saves us 500 microseconds per
      inode lookup in my testcase.  Thanks,
      Signed-off-by: NJosef Bacik <josef@redhat.com>
      d82a6f1d
    • J
      Btrfs: fix how we do space reservation for truncate · fcb80c2a
      Josef Bacik 提交于
      The ceph guys keep running into problems where we have space reserved in our
      orphan block rsv when freeing it up.  This is because they tend to do snapshots
      alot, so their truncates tend to use a bunch of space, so when we go to do
      things like update the inode we have to steal reservation space in order to make
      the reservation happen.  This happens because truncate can use as much space as
      it freaking feels like, but we still have to hold space for removing the orphan
      item and updating the inode, which will definitely always happen.  So in order
      to fix this we need to split all of the reservation stuf up.  So with this patch
      we have
      
      1) The orphan block reserve which only holds the space for deleting our orphan
      item when everything is over.
      
      2) The truncate block reserve which gets allocated and used specifically for the
      space that the truncate will use on a per truncate basis.
      
      3) The transaction will always have 1 item's worth of data reserved so we can
      update the inode normally.
      
      Hopefully this will make the ceph problem go away.  Thanks,
      Signed-off-by: NJosef Bacik <josef@redhat.com>
      fcb80c2a
    • J
      Btrfs: take away the num_items argument from btrfs_join_transaction · 7a7eaa40
      Josef Bacik 提交于
      I keep forgetting that btrfs_join_transaction() just ignores the num_items
      argument, which leads me to sending pointless patches and looking stupid :).  So
      just kill the num_items argument from btrfs_join_transaction and
      btrfs_start_ioctl_transaction, since neither of them use it.  Thanks,
      Signed-off-by: NJosef Bacik <josef@redhat.com>
      7a7eaa40
    • J
      Btrfs: make sure to use the delalloc reserve when filling delalloc · 74b21075
      Josef Bacik 提交于
      In the prealloc filling code and compressed code we don't set trans->block_rsv
      to the delalloc block reserve properly, which is going to make us use metadata
      from the wrong pool, this patch fixes that.  Thanks,
      Signed-off-by: NJosef Bacik <josef@redhat.com>
      74b21075
  14. 21 5月, 2011 1 次提交
    • M
      btrfs: implement delayed inode items operation · 16cdcec7
      Miao Xie 提交于
      Changelog V5 -> V6:
      - Fix oom when the memory load is high, by storing the delayed nodes into the
        root's radix tree, and letting btrfs inodes go.
      
      Changelog V4 -> V5:
      - Fix the race on adding the delayed node to the inode, which is spotted by
        Chris Mason.
      - Merge Chris Mason's incremental patch into this patch.
      - Fix deadlock between readdir() and memory fault, which is reported by
        Itaru Kitayama.
      
      Changelog V3 -> V4:
      - Fix nested lock, which is reported by Itaru Kitayama, by updating space cache
        inode in time.
      
      Changelog V2 -> V3:
      - Fix the race between the delayed worker and the task which does delayed items
        balance, which is reported by Tsutomu Itoh.
      - Modify the patch address David Sterba's comment.
      - Fix the bug of the cpu recursion spinlock, reported by Chris Mason
      
      Changelog V1 -> V2:
      - break up the global rb-tree, use a list to manage the delayed nodes,
        which is created for every directory and file, and used to manage the
        delayed directory name index items and the delayed inode item.
      - introduce a worker to deal with the delayed nodes.
      
      Compare with Ext3/4, the performance of file creation and deletion on btrfs
      is very poor. the reason is that btrfs must do a lot of b+ tree insertions,
      such as inode item, directory name item, directory name index and so on.
      
      If we can do some delayed b+ tree insertion or deletion, we can improve the
      performance, so we made this patch which implemented delayed directory name
      index insertion/deletion and delayed inode update.
      
      Implementation:
      - introduce a delayed root object into the filesystem, that use two lists to
        manage the delayed nodes which are created for every file/directory.
        One is used to manage all the delayed nodes that have delayed items. And the
        other is used to manage the delayed nodes which is waiting to be dealt with
        by the work thread.
      - Every delayed node has two rb-tree, one is used to manage the directory name
        index which is going to be inserted into b+ tree, and the other is used to
        manage the directory name index which is going to be deleted from b+ tree.
      - introduce a worker to deal with the delayed operation. This worker is used
        to deal with the works of the delayed directory name index items insertion
        and deletion and the delayed inode update.
        When the delayed items is beyond the lower limit, we create works for some
        delayed nodes and insert them into the work queue of the worker, and then
        go back.
        When the delayed items is beyond the upper bound, we create works for all
        the delayed nodes that haven't been dealt with, and insert them into the work
        queue of the worker, and then wait for that the untreated items is below some
        threshold value.
      - When we want to insert a directory name index into b+ tree, we just add the
        information into the delayed inserting rb-tree.
        And then we check the number of the delayed items and do delayed items
        balance. (The balance policy is above.)
      - When we want to delete a directory name index from the b+ tree, we search it
        in the inserting rb-tree at first. If we look it up, just drop it. If not,
        add the key of it into the delayed deleting rb-tree.
        Similar to the delayed inserting rb-tree, we also check the number of the
        delayed items and do delayed items balance.
        (The same to inserting manipulation)
      - When we want to update the metadata of some inode, we cached the data of the
        inode into the delayed node. the worker will flush it into the b+ tree after
        dealing with the delayed insertion and deletion.
      - We will move the delayed node to the tail of the list after we access the
        delayed node, By this way, we can cache more delayed items and merge more
        inode updates.
      - If we want to commit transaction, we will deal with all the delayed node.
      - the delayed node will be freed when we free the btrfs inode.
      - Before we log the inode items, we commit all the directory name index items
        and the delayed inode update.
      
      I did a quick test by the benchmark tool[1] and found we can improve the
      performance of file creation by ~15%, and file deletion by ~20%.
      
      Before applying this patch:
      Create files:
              Total files: 50000
              Total time: 1.096108
              Average time: 0.000022
      Delete files:
              Total files: 50000
              Total time: 1.510403
              Average time: 0.000030
      
      After applying this patch:
      Create files:
              Total files: 50000
              Total time: 0.932899
              Average time: 0.000019
      Delete files:
              Total files: 50000
              Total time: 1.215732
              Average time: 0.000024
      
      [1] http://marc.info/?l=linux-btrfs&m=128212635122920&q=p3
      
      Many thanks for Kitayama-san's help!
      Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
      Reviewed-by: NDavid Sterba <dave@jikos.cz>
      Tested-by: NTsutomu Itoh <t-itoh@jp.fujitsu.com>
      Tested-by: NItaru Kitayama <kitayama@cl.bb4u.ne.jp>
      Signed-off-by: NChris Mason <chris.mason@oracle.com>
      16cdcec7
  15. 13 5月, 2011 1 次提交
  16. 12 5月, 2011 1 次提交
    • A
      btrfs: scrub · a2de733c
      Arne Jansen 提交于
      This adds an initial implementation for scrub. It works quite
      straightforward. The usermode issues an ioctl for each device in the
      fs. For each device, it enumerates the allocated device chunks. For
      each chunk, the contained extents are enumerated and the data checksums
      fetched. The extents are read sequentially and the checksums verified.
      If an error occurs (checksum or EIO), a good copy is searched for. If
      one is found, the bad copy will be rewritten.
      All enumerations happen from the commit roots. During a transaction
      commit, the scrubs get paused and afterwards continue from the new
      roots.
      
      This commit is based on the series originally posted to linux-btrfs
      with some improvements that resulted from comments from David Sterba,
      Ilya Dryomov and Jan Schmidt.
      Signed-off-by: NArne Jansen <sensille@gmx.net>
      a2de733c
  17. 06 5月, 2011 2 次提交
  18. 02 5月, 2011 2 次提交