diff options
| author | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2007-09-13 14:28:14 +0300 |
|---|---|---|
| committer | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2007-10-14 13:10:21 +0300 |
| commit | e8823bd63d50bb1f9bd73f1197230e1f7217456a (patch) | |
| tree | 3b8b849512686aebda99f83d290c9e09ed983967 /drivers/mtd/ubi/ubi.h | |
| parent | 6986646ba752fef150286926aa922ef04e9d19dd (diff) | |
UBI: fix atomic LEB change problems
When the UBI device is nearly full, i.e. all LEBs are mapped, we have
only one spare LEB left - the one we reserved for WL purposes. Well,
I do not count the LEBs which were reserved for bad PEB handling -
suppose NOR flash for simplicity. If an "atomic LEB change operation"
is run, and the WL unit is moving a LEB, we have no spare LEBs to
finish the operation and fail, which is not good. Moreover, if there
are 2 or more simultanious "atomic LEB change" requests, only one of
them has chances to succeed, the other will fail with -ENOSPC. Not
good either.
This patch does 2 things:
1. Reserves one PEB for the "atomic LEB change" operation.
2. Serealize the operations so that only on of them may run
at a time (by means of a mutex).
Pointed-to-by: Brijesh Singh <brijesh.s.singh@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Diffstat (limited to 'drivers/mtd/ubi/ubi.h')
| -rw-r--r-- | drivers/mtd/ubi/ubi.h | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h index cc010111264..5e941a63303 100644 --- a/drivers/mtd/ubi/ubi.h +++ b/drivers/mtd/ubi/ubi.h @@ -221,14 +221,15 @@ struct ubi_wl_entry; * @vtbl_slots: how many slots are available in the volume table * @vtbl_size: size of the volume table in bytes * @vtbl: in-RAM volume table copy + * @vtbl_mutex: protects on-flash volume table * * @max_ec: current highest erase counter value * @mean_ec: current mean erase counter value * - * global_sqnum: global sequence number + * @global_sqnum: global sequence number * @ltree_lock: protects the lock tree and @global_sqnum * @ltree: the lock tree - * @vtbl_mutex: protects on-flash volume table + * @alc_mutex: serializes "atomic LEB change" operations * * @used: RB-tree of used physical eraseblocks * @free: RB-tree of free physical eraseblocks @@ -308,6 +309,7 @@ struct ubi_device { unsigned long long global_sqnum; spinlock_t ltree_lock; struct rb_root ltree; + struct mutex alc_mutex; /* Wear-leveling unit's stuff */ struct rb_root used; |