From 7b6c32daec3bff380ced6822002bc352bdf2c982 Mon Sep 17 00:00:00 2001 From: Xiaochuan-Xu Date: Mon, 15 Dec 2008 21:07:41 +0800 Subject: UBI: simplify PEB protection code UBI has 2 RB-trees to implement PEB protection, which is too much for simply prevent PEB from being moved for some time. This patch implements this using lists. The benefits: 1. No need to allocate protection entry on each PEB get. 2. No need to maintain balanced trees and walk them. Signed-off-by: Xiaochuan-Xu Signed-off-by: Artem Bityutskiy --- drivers/mtd/ubi/ubi.h | 39 ++++++++++++++++++++++----------------- 1 file changed, 22 insertions(+), 17 deletions(-) (limited to 'drivers/mtd/ubi/ubi.h') diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h index 46a4763f8e7..4a8ec485c91 100644 --- a/drivers/mtd/ubi/ubi.h +++ b/drivers/mtd/ubi/ubi.h @@ -73,6 +73,13 @@ */ #define UBI_IO_RETRIES 3 +/* + * Length of the protection queue. The length is effectively equivalent to the + * number of (global) erase cycles PEBs are protected from the wear-leveling + * worker. + */ +#define UBI_PROT_QUEUE_LEN 10 + /* * Error codes returned by the I/O sub-system. * @@ -96,6 +103,7 @@ enum { /** * struct ubi_wl_entry - wear-leveling entry. * @u.rb: link in the corresponding (free/used) RB-tree + * @u.list: link in the protection queue * @ec: erase counter * @pnum: physical eraseblock number * @@ -106,6 +114,7 @@ enum { struct ubi_wl_entry { union { struct rb_node rb; + struct list_head list; } u; int ec; int pnum; @@ -290,7 +299,7 @@ struct ubi_wl_entry; * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling * * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end - * of UBI ititializetion + * of UBI initialization * @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 @@ -308,18 +317,17 @@ struct ubi_wl_entry; * @used: RB-tree of used physical eraseblocks * @free: RB-tree of free physical eraseblocks * @scrub: RB-tree of physical eraseblocks which need scrubbing - * @prot: protection trees - * @prot.pnum: protection tree indexed by physical eraseblock numbers - * @prot.aec: protection tree indexed by absolute erase counter value - * @wl_lock: protects the @used, @free, @prot, @lookuptbl, @abs_ec, @move_from, - * @move_to, @move_to_put @erase_pending, @wl_scheduled, and @works - * fields + * @pq: protection queue (contain physical eraseblocks which are temporarily + * protected from the wear-leveling worker) + * @pq_head: protection queue head + * @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from, + * @move_to, @move_to_put @erase_pending, @wl_scheduled and @works + * fields * @move_mutex: serializes eraseblock moves - * @work_sem: sycnhronizes the WL worker with use tasks + * @work_sem: synchronizes the WL worker with use tasks * @wl_scheduled: non-zero if the wear-leveling was scheduled * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any * physical eraseblock - * @abs_ec: absolute erase counter * @move_from: physical eraseblock from where the data is being moved * @move_to: physical eraseblock where the data is being moved to * @move_to_put: if the "to" PEB was put @@ -353,11 +361,11 @@ struct ubi_wl_entry; * * @peb_buf1: a buffer of PEB size used for different purposes * @peb_buf2: another buffer of PEB size used for different purposes - * @buf_mutex: proptects @peb_buf1 and @peb_buf2 + * @buf_mutex: protects @peb_buf1 and @peb_buf2 * @ckvol_mutex: serializes static volume checking when opening - * @mult_mutex: serializes operations on multiple volumes, like re-nameing + * @mult_mutex: serializes operations on multiple volumes, like re-naming * @dbg_peb_buf: buffer of PEB size used for debugging - * @dbg_buf_mutex: proptects @dbg_peb_buf + * @dbg_buf_mutex: protects @dbg_peb_buf */ struct ubi_device { struct cdev cdev; @@ -394,16 +402,13 @@ struct ubi_device { struct rb_root used; struct rb_root free; struct rb_root scrub; - struct { - struct rb_root pnum; - struct rb_root aec; - } prot; + struct list_head pq[UBI_PROT_QUEUE_LEN]; + int pq_head; 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; struct ubi_wl_entry *move_from; struct ubi_wl_entry *move_to; int move_to_put; -- cgit v1.2.3-18-g5258