a) Rename ubi->fm_sem to ubi->fm_eba_sem as this semaphore protects EBA changes. b) Turn ubi->fm_mutex into a rw semaphore. It will still serialize fastmap writes but also ensures that ubi_wl_put_peb() is not interrupted by a fastmap write. We use a rw semaphore to allow ubi_wl_put_peb() still to be executed in parallel if no fastmap write is happening.
Signed-off-by: Richard Weinberger <[email protected]> --- drivers/mtd/ubi/build.c | 4 ++-- drivers/mtd/ubi/eba.c | 44 ++++++++++++++++++++++---------------------- drivers/mtd/ubi/fastmap.c | 18 +++++++++--------- drivers/mtd/ubi/ubi.h | 9 +++++---- drivers/mtd/ubi/wl.c | 17 +++++++++++------ 5 files changed, 49 insertions(+), 43 deletions(-) diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c index a047bb4..813143a 100644 --- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c @@ -969,8 +969,8 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, mutex_init(&ubi->ckvol_mutex); mutex_init(&ubi->device_mutex); spin_lock_init(&ubi->volumes_lock); - mutex_init(&ubi->fm_mutex); - init_rwsem(&ubi->fm_sem); + init_rwsem(&ubi->fm_protect); + init_rwsem(&ubi->fm_eba_sem); ubi_msg("attaching mtd%d to ubi%d", mtd->index, ubi_num); diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c index 2f41e53..1d0b453 100644 --- a/drivers/mtd/ubi/eba.c +++ b/drivers/mtd/ubi/eba.c @@ -340,9 +340,9 @@ int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol, dbg_eba("erase LEB %d:%d, PEB %d", vol_id, lnum, pnum); - down_read(&ubi->fm_sem); + down_read(&ubi->fm_eba_sem); vol->eba_tbl[lnum] = UBI_LEB_UNMAPPED; - up_read(&ubi->fm_sem); + up_read(&ubi->fm_eba_sem); err = ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 0); out_unlock: @@ -510,7 +510,7 @@ retry: new_pnum = ubi_wl_get_peb(ubi); if (new_pnum < 0) { ubi_free_vid_hdr(ubi, vid_hdr); - up_read(&ubi->fm_sem); + up_read(&ubi->fm_eba_sem); return new_pnum; } @@ -520,14 +520,14 @@ retry: if (err && err != UBI_IO_BITFLIPS) { if (err > 0) err = -EIO; - up_read(&ubi->fm_sem); + up_read(&ubi->fm_eba_sem); goto out_put; } vid_hdr->sqnum = cpu_to_be64(ubi_next_sqnum(ubi)); err = ubi_io_write_vid_hdr(ubi, new_pnum, vid_hdr); if (err) { - up_read(&ubi->fm_sem); + up_read(&ubi->fm_eba_sem); goto write_error; } @@ -539,7 +539,7 @@ retry: if (offset > 0) { err = ubi_io_read_data(ubi, ubi->peb_buf, pnum, 0, offset); if (err && err != UBI_IO_BITFLIPS) { - up_read(&ubi->fm_sem); + up_read(&ubi->fm_eba_sem); goto out_unlock; } } @@ -549,7 +549,7 @@ retry: err = ubi_io_write_data(ubi, ubi->peb_buf, new_pnum, 0, data_size); if (err) { mutex_unlock(&ubi->buf_mutex); - up_read(&ubi->fm_sem); + up_read(&ubi->fm_eba_sem); goto write_error; } @@ -557,7 +557,7 @@ retry: ubi_free_vid_hdr(ubi, vid_hdr); vol->eba_tbl[lnum] = new_pnum; - up_read(&ubi->fm_sem); + up_read(&ubi->fm_eba_sem); ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 1); ubi_msg("data was successfully recovered"); @@ -652,7 +652,7 @@ retry: if (pnum < 0) { ubi_free_vid_hdr(ubi, vid_hdr); leb_write_unlock(ubi, vol_id, lnum); - up_read(&ubi->fm_sem); + up_read(&ubi->fm_eba_sem); return pnum; } @@ -663,7 +663,7 @@ retry: if (err) { ubi_warn("failed to write VID header to LEB %d:%d, PEB %d", vol_id, lnum, pnum); - up_read(&ubi->fm_sem); + up_read(&ubi->fm_eba_sem); goto write_error; } @@ -672,13 +672,13 @@ retry: if (err) { ubi_warn("failed to write %d bytes at offset %d of LEB %d:%d, PEB %d", len, offset, vol_id, lnum, pnum); - up_read(&ubi->fm_sem); + up_read(&ubi->fm_eba_sem); goto write_error; } } vol->eba_tbl[lnum] = pnum; - up_read(&ubi->fm_sem); + up_read(&ubi->fm_eba_sem); leb_write_unlock(ubi, vol_id, lnum); ubi_free_vid_hdr(ubi, vid_hdr); @@ -775,7 +775,7 @@ retry: if (pnum < 0) { ubi_free_vid_hdr(ubi, vid_hdr); leb_write_unlock(ubi, vol_id, lnum); - up_read(&ubi->fm_sem); + up_read(&ubi->fm_eba_sem); return pnum; } @@ -786,7 +786,7 @@ retry: if (err) { ubi_warn("failed to write VID header to LEB %d:%d, PEB %d", vol_id, lnum, pnum); - up_read(&ubi->fm_sem); + up_read(&ubi->fm_eba_sem); goto write_error; } @@ -794,13 +794,13 @@ retry: if (err) { ubi_warn("failed to write %d bytes of data to PEB %d", len, pnum); - up_read(&ubi->fm_sem); + up_read(&ubi->fm_eba_sem); goto write_error; } ubi_assert(vol->eba_tbl[lnum] < 0); vol->eba_tbl[lnum] = pnum; - up_read(&ubi->fm_sem); + up_read(&ubi->fm_eba_sem); leb_write_unlock(ubi, vol_id, lnum); ubi_free_vid_hdr(ubi, vid_hdr); @@ -895,7 +895,7 @@ retry: pnum = ubi_wl_get_peb(ubi); if (pnum < 0) { err = pnum; - up_read(&ubi->fm_sem); + up_read(&ubi->fm_eba_sem); goto out_leb_unlock; } @@ -906,7 +906,7 @@ retry: if (err) { ubi_warn("failed to write VID header to LEB %d:%d, PEB %d", vol_id, lnum, pnum); - up_read(&ubi->fm_sem); + up_read(&ubi->fm_eba_sem); goto write_error; } @@ -914,13 +914,13 @@ retry: if (err) { ubi_warn("failed to write %d bytes of data to PEB %d", len, pnum); - up_read(&ubi->fm_sem); + up_read(&ubi->fm_eba_sem); goto write_error; } old_pnum = vol->eba_tbl[lnum]; vol->eba_tbl[lnum] = pnum; - up_read(&ubi->fm_sem); + up_read(&ubi->fm_eba_sem); if (old_pnum >= 0) { err = ubi_wl_put_peb(ubi, vol_id, lnum, old_pnum, 0); @@ -1173,9 +1173,9 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to, } ubi_assert(vol->eba_tbl[lnum] == from); - down_read(&ubi->fm_sem); + down_read(&ubi->fm_eba_sem); vol->eba_tbl[lnum] = to; - up_read(&ubi->fm_sem); + up_read(&ubi->fm_eba_sem); out_unlock_buf: mutex_unlock(&ubi->buf_mutex); diff --git a/drivers/mtd/ubi/fastmap.c b/drivers/mtd/ubi/fastmap.c index e563366..9a8cf45 100644 --- a/drivers/mtd/ubi/fastmap.c +++ b/drivers/mtd/ubi/fastmap.c @@ -874,7 +874,7 @@ int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai, __be32 crc, tmp_crc; unsigned long long sqnum = 0; - mutex_lock(&ubi->fm_mutex); + down_write(&ubi->fm_protect); memset(ubi->fm_buf, 0, ubi->fm_size); fmsb = kmalloc(sizeof(*fmsb), GFP_KERNEL); @@ -1064,7 +1064,7 @@ int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai, ubi_free_vid_hdr(ubi, vh); kfree(ech); out: - mutex_unlock(&ubi->fm_mutex); + up_write(&ubi->fm_protect); if (ret == UBI_BAD_FASTMAP) ubi_err("Attach by fastmap failed, doing a full scan!"); return ret; @@ -1432,24 +1432,24 @@ int ubi_update_fastmap(struct ubi_device *ubi) struct ubi_fastmap_layout *new_fm, *old_fm; struct ubi_wl_entry *tmp_e; - mutex_lock(&ubi->fm_mutex); + down_write(&ubi->fm_protect); ubi_refill_pools(ubi); if (ubi->ro_mode || ubi->fm_disabled) { - mutex_unlock(&ubi->fm_mutex); + up_write(&ubi->fm_protect); return 0; } ret = ubi_ensure_anchor_pebs(ubi); if (ret) { - mutex_unlock(&ubi->fm_mutex); + up_write(&ubi->fm_protect); return ret; } new_fm = kzalloc(sizeof(*new_fm), GFP_KERNEL); if (!new_fm) { - mutex_unlock(&ubi->fm_mutex); + up_write(&ubi->fm_protect); return -ENOMEM; } @@ -1539,16 +1539,16 @@ int ubi_update_fastmap(struct ubi_device *ubi) } down_write(&ubi->work_sem); - down_write(&ubi->fm_sem); + down_write(&ubi->fm_eba_sem); ret = ubi_write_fastmap(ubi, new_fm); - up_write(&ubi->fm_sem); + up_write(&ubi->fm_eba_sem); up_write(&ubi->work_sem); if (ret) goto err; out_unlock: - mutex_unlock(&ubi->fm_mutex); + up_write(&ubi->fm_protect); kfree(old_fm); return ret; diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h index 0392366..9a37fe3 100644 --- a/drivers/mtd/ubi/ubi.h +++ b/drivers/mtd/ubi/ubi.h @@ -425,10 +425,11 @@ struct ubi_debug_info { * @fm_pool: in-memory data structure of the fastmap pool * @fm_wl_pool: in-memory data structure of the fastmap pool used by the WL * sub-system - * @fm_mutex: serializes ubi_update_fastmap() and protects @fm_buf + * @fm_protect: serializes ubi_update_fastmap(), protects @fm_buf and makes sure + * that critical sections cannot be interrupted by ubi_update_fastmap() * @fm_buf: vmalloc()'d buffer which holds the raw fastmap * @fm_size: fastmap size in bytes - * @fm_sem: allows ubi_update_fastmap() to block EBA table changes + * @fm_eba_sem: allows ubi_update_fastmap() to block EBA table changes * @fm_work: fastmap work queue * @fm_work_scheduled: non-zero if fastmap work was scheduled * @@ -532,8 +533,8 @@ struct ubi_device { struct ubi_fastmap_layout *fm; struct ubi_fm_pool fm_pool; struct ubi_fm_pool fm_wl_pool; - struct rw_semaphore fm_sem; - struct mutex fm_mutex; + struct rw_semaphore fm_eba_sem; + struct rw_semaphore fm_protect; void *fm_buf; size_t fm_size; struct work_struct fm_work; diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c index fbe9b5c..ea3c79e 100644 --- a/drivers/mtd/ubi/wl.c +++ b/drivers/mtd/ubi/wl.c @@ -628,7 +628,7 @@ void ubi_refill_pools(struct ubi_device *ubi) /* ubi_wl_get_peb - works exaclty like __wl_get_peb but keeps track of * the fastmap pool. - * Returns with ubi->fm_sem held in read mode! + * Returns with ubi->fm_eba_sem held in read mode! */ int ubi_wl_get_peb(struct ubi_device *ubi) { @@ -637,19 +637,19 @@ int ubi_wl_get_peb(struct ubi_device *ubi) struct ubi_fm_pool *wl_pool = &ubi->fm_wl_pool; again: - down_read(&ubi->fm_sem); + down_read(&ubi->fm_eba_sem); spin_lock(&ubi->wl_lock); if (!pool->size || !wl_pool->size || pool->used >= pool->size || wl_pool->used >= wl_pool->size) { spin_unlock(&ubi->wl_lock); - up_read(&ubi->fm_sem); + up_read(&ubi->fm_eba_sem); ret = ubi_update_fastmap(ubi); if (ret) { ubi_msg("Unable to write a new fastmap: %i", ret); - down_read(&ubi->fm_sem); + down_read(&ubi->fm_eba_sem); return -ENOSPC; } - down_read(&ubi->fm_sem); + down_read(&ubi->fm_eba_sem); spin_lock(&ubi->wl_lock); } @@ -726,7 +726,7 @@ int ubi_wl_get_peb(struct ubi_device *ubi) return err; } - down_read(&ubi->fm_sem); + down_read(&ubi->fm_eba_sem); return peb; } #endif @@ -1602,6 +1602,8 @@ int ubi_wl_put_peb(struct ubi_device *ubi, int vol_id, int lnum, ubi_assert(pnum >= 0); ubi_assert(pnum < ubi->peb_count); + down_read(&ubi->fm_protect); + retry: spin_lock(&ubi->wl_lock); e = ubi->lookuptbl[pnum]; @@ -1632,6 +1634,7 @@ retry: ubi_assert(!ubi->move_to_put); ubi->move_to_put = 1; spin_unlock(&ubi->wl_lock); + up_read(&ubi->fm_protect); return 0; } else { if (in_wl_tree(e, &ubi->used)) { @@ -1653,6 +1656,7 @@ retry: ubi_err("PEB %d not found", pnum); ubi_ro_mode(ubi); spin_unlock(&ubi->wl_lock); + up_read(&ubi->fm_protect); return err; } } @@ -1666,6 +1670,7 @@ retry: spin_unlock(&ubi->wl_lock); } + up_read(&ubi->fm_protect); return err; } -- 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/
