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author | Jens Axboe <axboe@kernel.dk> | 2013-12-31 20:51:02 +0400 |
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committer | Jens Axboe <axboe@kernel.dk> | 2013-12-31 20:51:02 +0400 |
commit | b28bc9b38c52f63f43e3fd875af982f2240a2859 (patch) | |
tree | 76cdb7b52b58f5685993cc15ed81d1c903023358 /drivers/tty/tty_ldsem.c | |
parent | 8d30726912cb39c3a3ebde06214d54861f8fdde2 (diff) | |
parent | 802eee95bde72fd0cd0f3a5b2098375a487d1eda (diff) | |
download | linux-b28bc9b38c52f63f43e3fd875af982f2240a2859.tar.xz |
Merge tag 'v3.13-rc6' into for-3.14/core
Needed to bring blk-mq uptodate, since changes have been going in
since for-3.14/core was established.
Fixup merge issues related to the immutable biovec changes.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Conflicts:
block/blk-flush.c
fs/btrfs/check-integrity.c
fs/btrfs/extent_io.c
fs/btrfs/scrub.c
fs/logfs/dev_bdev.c
Diffstat (limited to 'drivers/tty/tty_ldsem.c')
-rw-r--r-- | drivers/tty/tty_ldsem.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/drivers/tty/tty_ldsem.c b/drivers/tty/tty_ldsem.c index 22fad8ad5ac2..d8a55e87877f 100644 --- a/drivers/tty/tty_ldsem.c +++ b/drivers/tty/tty_ldsem.c @@ -86,11 +86,21 @@ static inline long ldsem_atomic_update(long delta, struct ld_semaphore *sem) return atomic_long_add_return(delta, (atomic_long_t *)&sem->count); } +/* + * ldsem_cmpxchg() updates @*old with the last-known sem->count value. + * Returns 1 if count was successfully changed; @*old will have @new value. + * Returns 0 if count was not changed; @*old will have most recent sem->count + */ static inline int ldsem_cmpxchg(long *old, long new, struct ld_semaphore *sem) { - long tmp = *old; - *old = atomic_long_cmpxchg(&sem->count, *old, new); - return *old == tmp; + long tmp = atomic_long_cmpxchg(&sem->count, *old, new); + if (tmp == *old) { + *old = new; + return 1; + } else { + *old = tmp; + return 0; + } } /* |