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author | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2007-12-18 15:54:35 +0200 |
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committer | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2007-12-26 19:15:16 +0200 |
commit | 593dd33c92c6529443d5df1350dc5cc76511232d (patch) | |
tree | dda360da5a5f66eb36b55a4c2e8eb985e997ffd6 /drivers/mtd/ubi | |
parent | 458dbb3d07574e8fcdcb921ac155ccd81b16b05f (diff) | |
download | kernel_samsung_smdk4412-593dd33c92c6529443d5df1350dc5cc76511232d.zip kernel_samsung_smdk4412-593dd33c92c6529443d5df1350dc5cc76511232d.tar.gz kernel_samsung_smdk4412-593dd33c92c6529443d5df1350dc5cc76511232d.tar.bz2 |
UBI: fix ubi_wl_flush
The flush function should finish all the pending jobs. But if
somebody else is doing a work, this function should wait and let
it finish.
This patche uses rw semaphore for synchronization purpose - it
just looks quite convinient.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Diffstat (limited to 'drivers/mtd/ubi')
-rw-r--r-- | drivers/mtd/ubi/ubi.h | 1 | ||||
-rw-r--r-- | drivers/mtd/ubi/wl.c | 39 |
2 files changed, 33 insertions, 7 deletions
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h index ea9a699..994233d 100644 --- a/drivers/mtd/ubi/ubi.h +++ b/drivers/mtd/ubi/ubi.h @@ -355,6 +355,7 @@ struct ubi_device { } prot; spinlock_t wl_lock; struct mutex move_mutex; + struct rw_semaphore work_sem; int wl_scheduled; struct ubi_wl_entry **lookuptbl; unsigned long long abs_ec; diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c index a60f942..8421c7a 100644 --- a/drivers/mtd/ubi/wl.c +++ b/drivers/mtd/ubi/wl.c @@ -251,10 +251,18 @@ static int do_work(struct ubi_device *ubi) cond_resched(); + /* + * @ubi->work_sem is used to synchronize with the workers. Workers take + * it in read mode, so many of them may be doing works at a time. But + * the queue flush code has to be sure the whole queue of works is + * done, and it takes the mutex in write mode. + */ + down_read(&ubi->work_sem); spin_lock(&ubi->wl_lock); if (list_empty(&ubi->works)) { spin_unlock(&ubi->wl_lock); + up_read(&ubi->work_sem); return 0; } @@ -275,6 +283,7 @@ static int do_work(struct ubi_device *ubi) ubi->works_count -= 1; ubi_assert(ubi->works_count >= 0); spin_unlock(&ubi->wl_lock); + up_read(&ubi->work_sem); return err; } @@ -1173,7 +1182,7 @@ retry: * the WL unit has not put the PEB to the "used" tree yet, but * it is about to do this. So we just set a flag which will * tell the WL worker that the PEB is not needed anymore and - * should be sheduled for erasure. + * should be scheduled for erasure. */ dbg_wl("PEB %d is the target of data moving", pnum); ubi_assert(!ubi->move_to_put); @@ -1280,17 +1289,32 @@ retry: */ int ubi_wl_flush(struct ubi_device *ubi) { - int err, pending_count; - - pending_count = ubi->works_count; - - dbg_wl("flush (%d pending works)", pending_count); + int err; /* * Erase while the pending works queue is not empty, but not more then * the number of currently pending works. */ - while (pending_count-- > 0) { + dbg_wl("flush (%d pending works)", ubi->works_count); + while (ubi->works_count) { + err = do_work(ubi); + if (err) + return err; + } + + /* + * Make sure all the works which have been done in parallel are + * finished. + */ + down_write(&ubi->work_sem); + up_write(&ubi->work_sem); + + /* + * And in case last was the WL worker and it cancelled the LEB + * movement, flush again. + */ + while (ubi->works_count) { + dbg_wl("flush more (%d pending works)", ubi->works_count); err = do_work(ubi); if (err) return err; @@ -1426,6 +1450,7 @@ int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si) ubi->prot.pnum = ubi->prot.aec = RB_ROOT; spin_lock_init(&ubi->wl_lock); mutex_init(&ubi->move_mutex); + init_rwsem(&ubi->work_sem); ubi->max_ec = si->max_ec; INIT_LIST_HEAD(&ubi->works); |