This patch implements bitrot checking for UBI. ubi_wl_trigger_bitrot_check() triggers a re-read of every PEB which is currently in use.
Signed-off-by: Richard Weinberger <[email protected]> --- drivers/mtd/ubi/debug.c | 3 ++ drivers/mtd/ubi/eba.c | 2 +- drivers/mtd/ubi/ubi.h | 3 +- drivers/mtd/ubi/wl.c | 115 ++++++++++++++++++++++++++++++++++++++++++++---- 4 files changed, 112 insertions(+), 11 deletions(-) diff --git a/drivers/mtd/ubi/debug.c b/drivers/mtd/ubi/debug.c index 63cb1d7..80d7832 100644 --- a/drivers/mtd/ubi/debug.c +++ b/drivers/mtd/ubi/debug.c @@ -332,6 +332,9 @@ static ssize_t dfs_file_write(struct file *file, const char __user *user_buf, goto out; } + //XXX + ubi_wl_trigger_bitrot_check(ubi); + if (dent == d->dfs_chk_gen) d->chk_gen = val; else if (dent == d->dfs_chk_io) diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c index 0e11671d..78109e7 100644 --- a/drivers/mtd/ubi/eba.c +++ b/drivers/mtd/ubi/eba.c @@ -468,7 +468,7 @@ retry: } if (scrub) - err = ubi_wl_scrub_peb(ubi, pnum); + err = ubi_wl_scrub_peb(ubi, pnum, 0); leb_read_unlock(ubi, vol_id, lnum); return err; diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h index 7bf4163..ad004bd 100644 --- a/drivers/mtd/ubi/ubi.h +++ b/drivers/mtd/ubi/ubi.h @@ -806,7 +806,7 @@ int ubi_wl_get_peb(struct ubi_device *ubi); int ubi_wl_put_peb(struct ubi_device *ubi, int vol_id, int lnum, int pnum, int torture); int ubi_wl_flush(struct ubi_device *ubi, int vol_id, int lnum); -int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum); +int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum, int nested); int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai); void ubi_wl_close(struct ubi_device *ubi); int ubi_thread(void *u); @@ -816,6 +816,7 @@ int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *used_e, int ubi_is_erase_work(struct ubi_work *wrk); void ubi_refill_pools(struct ubi_device *ubi); int ubi_ensure_anchor_pebs(struct ubi_device *ubi); +void ubi_wl_trigger_bitrot_check(struct ubi_device *ubi); /* io.c */ int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset, diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c index 20f4917..80e451f 100644 --- a/drivers/mtd/ubi/wl.c +++ b/drivers/mtd/ubi/wl.c @@ -325,6 +325,20 @@ static int in_wl_tree(struct ubi_wl_entry *e, struct rb_root *root) return 0; } +static inline int in_pg(const struct ubi_device *ubi, struct ubi_wl_entry *e) +{ + struct ubi_wl_entry *p; + int i; + + for (i = 0; i < UBI_PROT_QUEUE_LEN; ++i) + list_for_each_entry(p, &ubi->pq[i], u.list) + if (p == e) + return 1; + + return 0; +} + + /** * prot_queue_add - add physical eraseblock to the protection queue. * @ubi: UBI device description object @@ -914,6 +928,93 @@ static int schedule_erase(struct ubi_device *ubi, struct ubi_wl_entry *e, } /** + * bitrot_check_worker - physical eraseblock bitrot check worker function. + * @ubi: UBI device description object + * @wl_wrk: the work object + * @shutdown: non-zero if the worker has to free memory and exit + * + * This function read a physical eraseblock and schedules scrubbing if + * bit flips are detected. + */ +static int bitrot_check_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk, + int shutdown) +{ + struct ubi_wl_entry *e = wl_wrk->e; + int err; + + kfree(wl_wrk); + if (shutdown) { + dbg_wl("cancel bitrot check of PEB %d", e->pnum); + kmem_cache_free(ubi_wl_entry_slab, e); + return 0; + } + + if (!in_wl_tree(e, &ubi->used) && !in_pg(ubi, e)) { + dbg_wl("PEB %d not in used tree nor in protection queue", e->pnum); + return 0; + } + + mutex_lock(&ubi->buf_mutex); + err = ubi_io_read(ubi, ubi->peb_buf, e->pnum, 0, ubi->peb_size); + mutex_unlock(&ubi->buf_mutex); + if (err == UBI_IO_BITFLIPS) + err = ubi_wl_scrub_peb(ubi, e->pnum, 1); + else + /* Ignore read errors as we return only work related errors. + * Read errors will be logged by ubi_io_read(). */ + err = 0; + + return err; +} + +/** + * schedule_bitrot_check - schedule a bitrot check work. + * @ubi: UBI device description object + * @e: the WL entry of the physical eraseblock to check + * + * This function returns zero in case of success and a %-ENOMEM in case of + * failure. + */ +static int schedule_bitrot_check(struct ubi_device *ubi, + struct ubi_wl_entry *e) +{ + struct ubi_work *wl_wrk; + + ubi_assert(e); + + dbg_wl("schedule bitrot check of PEB %d", e->pnum); + + wl_wrk = kmalloc(sizeof(struct ubi_work), GFP_NOFS); + if (!wl_wrk) + return -ENOMEM; + + wl_wrk->func = &bitrot_check_worker; + wl_wrk->e = e; + + schedule_ubi_work(ubi, wl_wrk); + return 0; +} + +/** + * ubi_wl_trigger_bitrot_check - triggers a re-read of all physical erase + * blocks in use. + * @ubi: UBI device description object + */ +void ubi_wl_trigger_bitrot_check(struct ubi_device *ubi) +{ + int i; + struct ubi_wl_entry *e; + + for (i = 0; i < ubi->peb_count; i++) { + spin_lock(&ubi->wl_lock); + e = ubi->lookuptbl[i]; + spin_unlock(&ubi->wl_lock); + if (e) + schedule_bitrot_check(ubi, e); + } +} + +/** * do_sync_erase - run the erase worker synchronously. * @ubi: UBI device description object * @e: the WL entry of the physical eraseblock to erase @@ -1634,13 +1735,14 @@ retry: * ubi_wl_scrub_peb - schedule a physical eraseblock for scrubbing. * @ubi: UBI device description object * @pnum: the physical eraseblock to schedule + * @nested: set to non-zero if this function is called from UBI worker * * If a bit-flip in a physical eraseblock is detected, this physical eraseblock * needs scrubbing. This function schedules a physical eraseblock for * scrubbing which is done in background. This function returns zero in case of * success and a negative error code in case of failure. */ -int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum) +int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum, int nested) { struct ubi_wl_entry *e; @@ -1690,7 +1792,7 @@ retry: * Technically scrubbing is the same as wear-leveling, so it is done * by the WL worker. */ - return ensure_wear_leveling(ubi, 0); + return ensure_wear_leveling(ubi, nested); } /** @@ -2117,16 +2219,11 @@ static int self_check_in_wl_tree(const struct ubi_device *ubi, static int self_check_in_pq(const struct ubi_device *ubi, struct ubi_wl_entry *e) { - struct ubi_wl_entry *p; - int i; - if (!ubi_dbg_chk_gen(ubi)) return 0; - for (i = 0; i < UBI_PROT_QUEUE_LEN; ++i) - list_for_each_entry(p, &ubi->pq[i], u.list) - if (p == e) - return 0; + if (!in_pg(ubi, e)) + return 0; ubi_err("self-check failed for PEB %d, EC %d, Protect queue", e->pnum, e->ec); -- 1.8.4.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
