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authorAl Viro <viro@zeniv.linux.org.uk>2013-10-25 16:39:14 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2013-11-15 22:04:17 -0500
commit2bc74feba12fbf052ec97aee8624c9f13593a9ac (patch)
tree411129cf4fe962f1afc2c9bca127d9db0924fbfd
parentb26d4cd385fc51e8844e2cdf9ba2051f5bba11a5 (diff)
take read_seqbegin_or_lock() and friends to seqlock.h
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--fs/dcache.c29
-rw-r--r--include/linux/seqlock.h29
2 files changed, 29 insertions, 29 deletions
diff --git a/fs/dcache.c b/fs/dcache.c
index 0a38ef8d7f00..667e23ab0b4c 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -88,35 +88,6 @@ EXPORT_SYMBOL(rename_lock);
88 88
89static struct kmem_cache *dentry_cache __read_mostly; 89static struct kmem_cache *dentry_cache __read_mostly;
90 90
91/**
92 * read_seqbegin_or_lock - begin a sequence number check or locking block
93 * @lock: sequence lock
94 * @seq : sequence number to be checked
95 *
96 * First try it once optimistically without taking the lock. If that fails,
97 * take the lock. The sequence number is also used as a marker for deciding
98 * whether to be a reader (even) or writer (odd).
99 * N.B. seq must be initialized to an even number to begin with.
100 */
101static inline void read_seqbegin_or_lock(seqlock_t *lock, int *seq)
102{
103 if (!(*seq & 1)) /* Even */
104 *seq = read_seqbegin(lock);
105 else /* Odd */
106 read_seqlock_excl(lock);
107}
108
109static inline int need_seqretry(seqlock_t *lock, int seq)
110{
111 return !(seq & 1) && read_seqretry(lock, seq);
112}
113
114static inline void done_seqretry(seqlock_t *lock, int seq)
115{
116 if (seq & 1)
117 read_sequnlock_excl(lock);
118}
119
120/* 91/*
121 * This is the single most critical data structure when it comes 92 * This is the single most critical data structure when it comes
122 * to the dcache: the hashtable for lookups. Somebody should try 93 * to the dcache: the hashtable for lookups. Somebody should try
diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h
index 1e8a8b6e837d..cf87a24c0f92 100644
--- a/include/linux/seqlock.h
+++ b/include/linux/seqlock.h
@@ -354,6 +354,35 @@ static inline void read_sequnlock_excl(seqlock_t *sl)
354 spin_unlock(&sl->lock); 354 spin_unlock(&sl->lock);
355} 355}
356 356
357/**
358 * read_seqbegin_or_lock - begin a sequence number check or locking block
359 * @lock: sequence lock
360 * @seq : sequence number to be checked
361 *
362 * First try it once optimistically without taking the lock. If that fails,
363 * take the lock. The sequence number is also used as a marker for deciding
364 * whether to be a reader (even) or writer (odd).
365 * N.B. seq must be initialized to an even number to begin with.
366 */
367static inline void read_seqbegin_or_lock(seqlock_t *lock, int *seq)
368{
369 if (!(*seq & 1)) /* Even */
370 *seq = read_seqbegin(lock);
371 else /* Odd */
372 read_seqlock_excl(lock);
373}
374
375static inline int need_seqretry(seqlock_t *lock, int seq)
376{
377 return !(seq & 1) && read_seqretry(lock, seq);
378}
379
380static inline void done_seqretry(seqlock_t *lock, int seq)
381{
382 if (seq & 1)
383 read_sequnlock_excl(lock);
384}
385
357static inline void read_seqlock_excl_bh(seqlock_t *sl) 386static inline void read_seqlock_excl_bh(seqlock_t *sl)
358{ 387{
359 spin_lock_bh(&sl->lock); 388 spin_lock_bh(&sl->lock);