1. 04 Feb, 2009 10 commits
    • Chris Ball's avatar
      Btrfs: Handle SGID bit when creating inodes · 8c087b51
      Chris Ball authored
      
      Before this patch, new files/dirs would ignore the SGID bit on their
      parent directory and always be owned by the creating user's uid/gid.
      
      Signed-off-by: default avatarChris Ball <cjb@laptop.org>
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      
      8c087b51
    • Chris Mason's avatar
      Btrfs: Make btrfs_drop_snapshot work in larger and more efficient chunks · bd56b302
      Chris Mason authored
      
      
      Every transaction in btrfs creates a new snapshot, and then schedules the
      snapshot from the last transaction for deletion.  Snapshot deletion
      works by walking down the btree and dropping the reference counts
      on each btree block during the walk.
      
      If if a given leaf or node has a reference count greater than one,
      the reference count is decremented and the subtree pointed to by that
      node is ignored.
      
      If the reference count is one, walking continues down into that node
      or leaf, and the references of everything it points to are decremented.
      
      The old code would try to work in small pieces, walking down the tree
      until it found the lowest leaf or node to free and then returning.  This
      was very friendly to the rest of the FS because it didn't have a huge
      impact on other operations.
      
      But it wouldn't always keep up with the rate that new commits added new
      snapshots for deletion, and it wasn't very optimal for the extent
      allocation tree because it wasn't finding leaves that were close together
      on disk and processing them at the same time.
      
      This changes things to walk down to a level 1 node and then process it
      in bulk.  All the leaf pointers are sorted and the leaves are dropped
      in order based on their extent number.
      
      The extent allocation tree and commit code are now fast enough for
      this kind of bulk processing to work without slowing the rest of the FS
      down.  Overall it does less IO and is better able to keep up with
      snapshot deletions under high load.
      
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      bd56b302
    • Chris Mason's avatar
      Btrfs: Change btree locking to use explicit blocking points · b4ce94de
      Chris Mason authored
      
      
      Most of the btrfs metadata operations can be protected by a spinlock,
      but some operations still need to schedule.
      
      So far, btrfs has been using a mutex along with a trylock loop,
      most of the time it is able to avoid going for the full mutex, so
      the trylock loop is a big performance gain.
      
      This commit is step one for getting rid of the blocking locks entirely.
      btrfs_tree_lock takes a spinlock, and the code explicitly switches
      to a blocking lock when it starts an operation that can schedule.
      
      We'll be able get rid of the blocking locks in smaller pieces over time.
      Tracing allows us to find the most common cause of blocking, so we
      can start with the hot spots first.
      
      The basic idea is:
      
      btrfs_tree_lock() returns with the spin lock held
      
      btrfs_set_lock_blocking() sets the EXTENT_BUFFER_BLOCKING bit in
      the extent buffer flags, and then drops the spin lock.  The buffer is
      still considered locked by all of the btrfs code.
      
      If btrfs_tree_lock gets the spinlock but finds the blocking bit set, it drops
      the spin lock and waits on a wait queue for the blocking bit to go away.
      
      Much of the code that needs to set the blocking bit finishes without actually
      blocking a good percentage of the time.  So, an adaptive spin is still
      used against the blocking bit to avoid very high context switch rates.
      
      btrfs_clear_lock_blocking() clears the blocking bit and returns
      with the spinlock held again.
      
      btrfs_tree_unlock() can be called on either blocking or spinning locks,
      it does the right thing based on the blocking bit.
      
      ctree.c has a helper function to set/clear all the locked buffers in a
      path as blocking.
      
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      b4ce94de
    • Chris Mason's avatar
      Btrfs: hash_lock is no longer needed · c487685d
      Chris Mason authored
      
      
      Before metadata is written to disk, it is updated to reflect that writeout
      has begun.  Once this update is done, the block must be cow'd before it
      can be modified again.
      
      This update was originally synchronized by using a per-fs spinlock.  Today
      the buffers for the metadata blocks are locked before writeout begins,
      and everyone that tests the flag has the buffer locked as well.
      
      So, the per-fs spinlock (called hash_lock for no good reason) is no
      longer required.
      
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      c487685d
    • Chris Mason's avatar
      Btrfs: disable leak debugging checks in extent_io.c · 3935127c
      Chris Mason authored
      
      
      extent_io.c has debugging code to report and free leaked extent_state
      and extent_buffer objects at rmmod time.  This helps track down
      leaks and it saves you from rebooting just to properly remove the
      kmem_cache object.
      
      But, the code runs under a fairly expensive spinlock and the checks to
      see if it is currently enabled are not entirely consistent.  Some use
      #ifdef and some #if.
      
      This changes everything to #if and disables the leak checking.
      
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      3935127c
    • Chris Mason's avatar
      Btrfs: sort references by byte number during btrfs_inc_ref · b7a9f29f
      Chris Mason authored
      
      
      When a block goes through cow, we update the reference counts of
      everything that block points to.  The internal pointers of the block
      can be in just about any order, and it is likely to have clusters of
      things that are close together and clusters of things that are not.
      
      To help reduce the seeks that come with updating all of these reference
      counts, sort them by byte number before actual updates are done.
      
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      b7a9f29f
    • Chris Mason's avatar
      Btrfs: async threads should try harder to find work · b51912c9
      Chris Mason authored
      
      
      Tracing shows the delay between when an async thread goes to sleep
      and when more work is added is often very short.  This commit adds
      a little bit of delay and extra checking to the code right before
      we schedule out.
      
      It allows more work to be added to the worker
      without requiring notifications from other procs.
      
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      b51912c9
    • Jim Owens's avatar
      Btrfs: selinux support · 0279b4cd
      Jim Owens authored
      
      Add call to LSM security initialization and save
      resulting security xattr for new inodes.
      
      Add xattr support to symlink inode ops.
      
      Set inode->i_op for existing special files.
      
      Signed-off-by: default avatarjim owens <jowens@hp.com>
      0279b4cd
    • Christian Hesse's avatar
      Btrfs: make btrfs acls selectable · bef62ef3
      Christian Hesse authored
      
      This patch adds a menu entry to kconfig to enable acls for btrfs.
      This allows you to enable FS_POSIX_ACL at kernel compile time.
      
      (updated by Jeff Mahoney to make the changes in fs/btrfs/Kconfig instead)
      
      Signed-off-by: default avatarChristian Hesse <mail@earthworm.de>
      Signed-off-by: default avatarJeff Mahoney <jeffm@suse.com>
      bef62ef3
    • Chris Mason's avatar
      Btrfs: Catch missed bios in the async bio submission thread · a6837051
      Chris Mason authored
      
      
      The async bio submission thread was missing some bios that were
      added after it had decided there was no work left to do.
      
      Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
      a6837051
  2. 28 Jan, 2009 7 commits
  3. 27 Jan, 2009 23 commits