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authorLinus Torvalds <torvalds@linux-foundation.org>2008-08-13 15:17:49 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-08-13 15:17:49 -0700
commit9ea319b61613085f501a79cf8d405cb221d084f3 (patch)
tree5bf7e1b9f104a0df029d355927fa9eb398db37bb /include/linux
parent3e11acd4306d558249c31cf6cac09f218f2de52e (diff)
parentc6a7b0f8a49aa71792dd108efc535435f462bf79 (diff)
Merge git://oss.sgi.com:8090/xfs/linux-2.6
* git://oss.sgi.com:8090/xfs/linux-2.6: (45 commits) [XFS] Fix use after free in xfs_log_done(). [XFS] Make xfs_bmap_*_count_leaves void. [XFS] Use KM_NOFS for debug trace buffers [XFS] use KM_MAYFAIL in xfs_mountfs [XFS] refactor xfs_mount_free [XFS] don't call xfs_freesb from xfs_unmountfs [XFS] xfs_unmountfs should return void [XFS] cleanup xfs_mountfs [XFS] move root inode IRELE into xfs_unmountfs [XFS] stop using file_update_time [XFS] optimize xfs_ichgtime [XFS] update timestamp in xfs_ialloc manually [XFS] remove the sema_t from XFS. [XFS] replace dquot flush semaphore with a completion [XFS] replace inode flush semaphore with a completion [XFS] extend completions to provide XFS object flush requirements [XFS] replace the XFS buf iodone semaphore with a completion [XFS] clean up stale references to semaphores [XFS] use get_unaligned_* helpers [XFS] Fix compile failure in xfs_buf_trace() ...
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/completion.h45
1 files changed, 45 insertions, 0 deletions
diff --git a/include/linux/completion.h b/include/linux/completion.h
index d2961b66d53d..57faa60de9bd 100644
--- a/include/linux/completion.h
+++ b/include/linux/completion.h
@@ -55,4 +55,49 @@ extern void complete_all(struct completion *);
#define INIT_COMPLETION(x) ((x).done = 0)
+
+/**
+ * try_wait_for_completion - try to decrement a completion without blocking
+ * @x: completion structure
+ *
+ * Returns: 0 if a decrement cannot be done without blocking
+ * 1 if a decrement succeeded.
+ *
+ * If a completion is being used as a counting completion,
+ * attempt to decrement the counter without blocking. This
+ * enables us to avoid waiting if the resource the completion
+ * is protecting is not available.
+ */
+static inline bool try_wait_for_completion(struct completion *x)
+{
+ int ret = 1;
+
+ spin_lock_irq(&x->wait.lock);
+ if (!x->done)
+ ret = 0;
+ else
+ x->done--;
+ spin_unlock_irq(&x->wait.lock);
+ return ret;
+}
+
+/**
+ * completion_done - Test to see if a completion has any waiters
+ * @x: completion structure
+ *
+ * Returns: 0 if there are waiters (wait_for_completion() in progress)
+ * 1 if there are no waiters.
+ *
+ */
+static inline bool completion_done(struct completion *x)
+{
+ int ret = 1;
+
+ spin_lock_irq(&x->wait.lock);
+ if (!x->done)
+ ret = 0;
+ spin_unlock_irq(&x->wait.lock);
+ return ret;
+}
+
#endif