Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757500Ab2EOHol (ORCPT ); Tue, 15 May 2012 03:44:41 -0400 Received: from static.78-46-68-141.clients.your-server.de ([78.46.68.141]:51887 "HELO eristoteles.iwoars.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with SMTP id S1757256Ab2EOHoj (ORCPT ); Tue, 15 May 2012 03:44:39 -0400 Date: Tue, 15 May 2012 09:44:34 +0200 (CEST) From: Joel Reardon X-X-Sender: joel@eristoteles.iwoars.net To: Artem Bityutskiy cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH V2] UBI: add ubi_lnum_purge function to clear work queue for a lnum Message-ID: User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5699 Lines: 156 This is the second part of a patch to allow UBI to force the erasure of particular logical eraseblock numbers. In this patch, a new function, ubi_lnum_purge, is added that allows the caller to synchronously erase all unmapped erase blocks whose LEB number corresponds to the parameter. This requires a previous patch that stores the LEB number in struct ubi_work. This was tested by disabling the call to do_work in ubi thread, which results in the work queue remaining unless explicitly called to remove. UBIFS was changed to call ubifs_leb_change 50 times for three different LEBs. Then the new function was called to clear the queue for the three differnt LEB numbers one at a time. The work queue was dumped each time and the selective removal of the particular LEB numbers was observed. Signed-off-by: Joel Reardon --- drivers/mtd/ubi/kapi.c | 31 +++++++++++++++++++++++++++++++ drivers/mtd/ubi/ubi.h | 1 + drivers/mtd/ubi/wl.c | 42 +++++++++++++++++++++++++++++++++++++++++- include/linux/mtd/ubi.h | 1 + 4 files changed, 74 insertions(+), 1 deletions(-) diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c index 33ede23..a236522 100644 --- a/drivers/mtd/ubi/kapi.c +++ b/drivers/mtd/ubi/kapi.c @@ -704,6 +704,37 @@ int ubi_sync(int ubi_num) } EXPORT_SYMBOL_GPL(ubi_sync); +/** + * ubi_lnum_purge - synchronously erase unmapped PEBs by LEB number. + * @ubi_num: UBI device to erase PEBs + * @lnum: the LEB number to erase old unmapped PEBs. + * + * This function is designed to offer a means to ensure that the contents of + * old, unmapped LEBs are securely erased without having to flush the entire + * work queue of all erase blocks that need erasure. Simply erasing the block + * at the time of unmapped is insufficient, as the wear-levelling subsystem + * may have already moved the contents. This function navigates the list of + * erase blocks that need erasures, and performs an immediate and synchronous + * erasure of any erase block that has held data for this particular @lnum. + * This may include eraseblocks that held older versions of the same @lnum. + * Returns zero in case of success and a negative error code in case of + * failure. + */ +int ubi_lnum_purge(int ubi_num, int lnum) +{ + int err; + struct ubi_device *ubi; + + ubi = ubi_get_device(ubi_num); + if (!ubi) + return -ENODEV; + + err = ubi_wl_flush_lnum(ubi, lnum); + ubi_put_device(ubi); + return err; +} +EXPORT_SYMBOL_GPL(ubi_lnum_purge); + BLOCKING_NOTIFIER_HEAD(ubi_notifiers); /** diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h index b3e5815..f91f965 100644 --- a/drivers/mtd/ubi/ubi.h +++ b/drivers/mtd/ubi/ubi.h @@ -535,6 +535,7 @@ int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si); int ubi_wl_get_peb(struct ubi_device *ubi); int ubi_wl_put_peb(struct ubi_device *ubi, int pnum, int torture, int lnum); int ubi_wl_flush(struct ubi_device *ubi); +int ubi_wl_flush_lnum(struct ubi_device *ubi, int lnum); int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum); int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si); void ubi_wl_close(struct ubi_device *ubi); diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c index 4e51735..56d9836 100644 --- a/drivers/mtd/ubi/wl.c +++ b/drivers/mtd/ubi/wl.c @@ -610,7 +610,6 @@ static int schedule_erase(struct ubi_device *ubi, struct ubi_wl_entry *e, wl_wrk->e = e; wl_wrk->torture = torture; wl_wrk->lnum = lnum; - schedule_ubi_work(ubi, wl_wrk); return 0; } @@ -1237,6 +1236,47 @@ retry: } /** + * ubi_wl_flush_lnum - flush all pending works associated with a LEB number + * @ubi: UBI device description object + * @lnum: the LEB number only for which work should be synchronously executed + * + * This function executes pending works for PEBs which are associated with a + * particular LEB number. If one of the pending works fail, for instance, due + * to the erase block becoming bad block during erasure, then it returns the + * error without continuing, but removes the work from the queue. This + * function returns zero if no work on the queue remains for lnum and all work + * in the call executed successfully. + */ +int ubi_wl_flush_lnum(struct ubi_device *ubi, int lnum) +{ + int err = 0; + struct ubi_work *wrk, *tmp; + + /* For each pending work, if it corresponds to the parameter @lnum, + * then execute the work. + */ + dbg_wl("flush lnum %d", lnum); + list_for_each_entry_safe(wrk, tmp, &ubi->works, list) { + if (wrk->lnum == lnum) { + down_read(&ubi->work_sem); + spin_lock(&ubi->wl_lock); + + list_del(&wrk->list); + ubi->works_count -= 1; + ubi_assert(ubi->works_count >= 0); + spin_unlock(&ubi->wl_lock); + + err = wrk->func(ubi, wrk, 0); + up_read(&ubi->work_sem); + if (err) + return err; + } + } + + return err; +} + +/** * ubi_wl_flush - flush all pending works. * @ubi: UBI device description object * diff --git a/include/linux/mtd/ubi.h b/include/linux/mtd/ubi.h index 9838dce..8087e99 100644 --- a/include/linux/mtd/ubi.h +++ b/include/linux/mtd/ubi.h @@ -216,6 +216,7 @@ int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum); int ubi_leb_map(struct ubi_volume_desc *desc, int lnum); int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum); int ubi_sync(int ubi_num); +int ubi_lnum_purge(int ubi_num, int lnum); /* * This function is the same as the 'ubi_leb_read()' function, but it does not -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/