1. 06 Jan, 2009 1 commit
  2. 09 Oct, 2008 1 commit
    • Tejun Heo's avatar
      klist: don't iterate over deleted entries · a1ed5b0c
      Tejun Heo authored
      A klist entry is kept on the list till all its current iterations are
      finished; however, a new iteration after deletion also iterates over
      deleted entries as long as their reference count stays above zero.
      This causes problems for cases where there are users which iterate
      over the list while synchronized against list manipulations and
      natuarally expect already deleted entries to not show up during
      iteration.
      
      This patch implements dead flag which gets set on deletion so that
      iteration can skip already deleted entries.  The dead flag piggy backs
      on the lowest bit of knode->n_klist and only visible to klist
      implementation proper.
      
      While at it, drop klist_iter->i_head as it's redundant and doesn't
      offer anything in semantics or performance wise as klist_iter->i_klist
      is dereferenced on every iteration anyway.
      Signed-off-by: default avatarTejun Heo <[email protected]>
      Cc: Greg Kroah-Hartman <[email protected]>
      Cc: Alan Stern <[email protected]>
      Cc: Jens Axboe <[email protected]>
      Signed-off-by: default avatarJens Axboe <[email protected]>
      a1ed5b0c
  3. 30 Apr, 2008 2 commits
  4. 26 Sep, 2006 1 commit
    • Alan Stern's avatar
      Driver core: Don't call put methods while holding a spinlock · 7e9f4b2d
      Alan Stern authored
      The klist utility routines currently call _put methods while holding a
      spinlock.  This is of course illegal; a put routine could try to
      unregister a device and hence need to sleep.
      
      No problems have arisen until now because in many cases klist removals
      were done synchronously, so the _put methods were never actually used.
      In other cases we may simply have been lucky.
      
      This patch (as784) reworks the klist routines so that _put methods are
      called only _after_ the klist's spinlock has been released.
      Signed-off-by: default avatarAlan Stern <[email protected]>
      Signed-off-by: default avatarGreg Kroah-Hartman <[email protected]>
      7e9f4b2d
  5. 05 Jan, 2006 1 commit
  6. 08 Sep, 2005 1 commit
  7. 05 Sep, 2005 1 commit
  8. 20 Jun, 2005 3 commits
    • mochel@digitalimplant.org's avatar
      [PATCH] Don't reference NULL klist pointer in klist_remove(). · 0293a509
      [email protected] authored
      Signed-off-by: default avatarPatrick Mochel <[email protected]>
      Signed-off-by: default avatarGreg Kroah-Hartman <[email protected]>
      
      diff -Nru a/lib/klist.c b/lib/klist.c
      0293a509
    • mochel@digitalimplant.org's avatar
      [PATCH] add klist_node_attached() to determine if a node is on a list or not. · 8b0c250b
      [email protected] authored
      Signed-off-by: default avatarPatrick Mochel <[email protected]>
      Signed-off-by: default avatarGreg Kroah-Hartman <[email protected]>
      
      diff -Nru a/include/linux/klist.h b/include/linux/klist.h
      8b0c250b
    • mochel@digitalimplant.org's avatar
      [PATCH] Add initial implementation of klist helpers. · 9a19fea4
      [email protected] authored
      This klist interface provides a couple of structures that wrap around
      struct list_head to provide explicit list "head" (struct klist) and
      list "node" (struct klist_node) objects. For struct klist, a spinlock
      is included that protects access to the actual list itself. struct
      klist_node provides a pointer to the klist that owns it and a kref
      reference count that indicates the number of current users of that node
      in the list.
      
      The entire point is to provide an interface for iterating over a list
      that is safe and allows for modification of the list during the
      iteration (e.g. insertion and removal), including modification of the
      current node on the list.
      
      It works using a 3rd object type - struct klist_iter - that is declared
      and initialized before an iteration. klist_next() is used to acquire the
      next element in the list. It returns NULL if there are no more items.
      This klist interface provides a couple of structures that wrap around
      struct list_head to provide explicit list "head" (struct klist) and
      list "node" (struct klist_node) objects. For struct klist, a spinlock
      is included that protects access to the actual list itself. struct
      klist_node provides a pointer to the klist that owns it and a kref
      reference count that indicates the number of current users of that node
      in the list.
      
      The entire point is to provide an interface for iterating over a list
      that is safe and allows for modification of the list during the
      iteration (e.g. insertion and removal), including modification of the
      current node on the list.
      
      It works using a 3rd object type - struct klist_iter - that is declared
      and initialized before an iteration. klist_next() is used to acquire the
      next element in the list. It returns NULL if there are no more items.
      Internally, that routine takes the klist's lock, decrements the reference
      count of the previous klist_node and increments the count of the next
      klist_node. It then drops the lock and returns.
      
      There are primitives for adding and removing nodes to/from a klist.
      When deleting, klist_del() will simply decrement the reference count.
      Only when the count goes to 0 is the node removed from the list.
      klist_remove() will try to delete the node from the list and block
      until it is actually removed. This is useful for objects (like devices)
      that have been removed from the system and must be freed (but must wait
      until all accessors have finished).
      
      Internally, that routine takes the klist's lock, decrements the reference
      count of the previous klist_node and increments the count of the next
      klist_node. It then drops the lock and returns.
      
      There are primitives for adding and removing nodes to/from a klist.
      When deleting, klist_del() will simply decrement the reference count.
      Only when the count goes to 0 is the node removed from the list.
      klist_remove() will try to delete the node from the list and block
      until it is actually removed. This is useful for objects (like devices)
      that have been removed from the system and must be freed (but must wait
      until all accessors have finished).
      Signed-off-by: default avatarPatrick Mochel <[email protected]>
      Signed-off-by: default avatarGreg Kroah-Hartman <[email protected]>
      
      diff -Nru a/include/linux/klist.h b/include/linux/klist.h
      9a19fea4