From 40a71a87fa8e0cb3ec0fca4d152263734b203eb2 Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Sun, 28 Jun 2009 19:16:55 +0300 Subject: UBI: add empty eraseblocks verification This patch adds code which makes sure eraseblocks contain all 0xFF bytes before starting using them. The verification is done only when debugging checks are enabled. Signed-off-by: Artem Bityutskiy --- drivers/mtd/ubi/debug.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'drivers/mtd/ubi/debug.h') diff --git a/drivers/mtd/ubi/debug.h b/drivers/mtd/ubi/debug.h index 13777e5beac..6fc7fda2ab9 100644 --- a/drivers/mtd/ubi/debug.h +++ b/drivers/mtd/ubi/debug.h @@ -93,6 +93,12 @@ void ubi_dbg_dump_mkvol_req(const struct ubi_mkvol_req *req); #define UBI_IO_DEBUG 0 #endif +#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID +int ubi_dbg_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len); +#else +#define ubi_dbg_check_all_ff(ubi, pnum, offset, len) 0 +#endif + #ifdef CONFIG_MTD_UBI_DEBUG_DISABLE_BGT #define DBG_DISABLE_BGT 1 #else -- cgit v1.2.3-70-g09d2 From 1398788fe7b730db10e97dcb9f838603e41922d5 Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Mon, 29 Jun 2009 15:58:36 +0300 Subject: UBI: remove bogus debugging checks The 'paranoid_check_empty()' is bogus because, which is easilly seen on NOR flash, which has long erase cycles, and which may easilly end-up with half-erased eraseblocks. In this case the paranoid check fails. I is just wrong to assume that PEBs which do not have EC headers always contain all 0xFF. Such assumption should not be made on the I/O level, which is quite low. Thus, just kill the check. Signed-off-by: Artem Bityutskiy --- drivers/mtd/ubi/debug.h | 1 + drivers/mtd/ubi/io.c | 87 ------------------------------------------------- drivers/mtd/ubi/wl.c | 2 +- 3 files changed, 2 insertions(+), 88 deletions(-) (limited to 'drivers/mtd/ubi/debug.h') diff --git a/drivers/mtd/ubi/debug.h b/drivers/mtd/ubi/debug.h index 6fc7fda2ab9..a4da7a09b94 100644 --- a/drivers/mtd/ubi/debug.h +++ b/drivers/mtd/ubi/debug.h @@ -173,6 +173,7 @@ static inline int ubi_dbg_is_erase_failure(void) #define ubi_dbg_is_bitflip() 0 #define ubi_dbg_is_write_failure() 0 #define ubi_dbg_is_erase_failure() 0 +#define ubi_dbg_check_all_ff(ubi, pnum, offset, len) 0 #endif /* !CONFIG_MTD_UBI_DEBUG */ #endif /* !__UBI_DEBUG_H__ */ diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c index 6c5441e8791..c8edbfd09b6 100644 --- a/drivers/mtd/ubi/io.c +++ b/drivers/mtd/ubi/io.c @@ -98,14 +98,12 @@ static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum, static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum); static int paranoid_check_vid_hdr(const struct ubi_device *ubi, int pnum, const struct ubi_vid_hdr *vid_hdr); -static int paranoid_check_empty(struct ubi_device *ubi, int pnum); #else #define paranoid_check_not_bad(ubi, pnum) 0 #define paranoid_check_peb_ec_hdr(ubi, pnum) 0 #define paranoid_check_ec_hdr(ubi, pnum, ec_hdr) 0 #define paranoid_check_peb_vid_hdr(ubi, pnum) 0 #define paranoid_check_vid_hdr(ubi, pnum, vid_hdr) 0 -#define paranoid_check_empty(ubi, pnum) 0 #endif /** @@ -669,10 +667,6 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum, if (read_err != -EBADMSG && check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) { /* The physical eraseblock is supposedly empty */ - err = ubi_dbg_check_all_ff(ubi, pnum, 0, ubi->peb_size); - if (err) - return err > 0 ? UBI_IO_BAD_EC_HDR : err; - if (verbose) ubi_warn("no EC header found at PEB %d, " "only 0xFF bytes", pnum); @@ -943,15 +937,6 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum, if (read_err != -EBADMSG && check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) { /* The physical eraseblock is supposedly free */ - - /* - * The below is just a paranoid check, it has to be - * compiled out if paranoid checks are disabled. - */ - err = paranoid_check_empty(ubi, pnum); - if (err) - return err > 0 ? UBI_IO_BAD_VID_HDR : err; - if (verbose) ubi_warn("no VID header found at PEB %d, " "only 0xFF bytes", pnum); @@ -1241,8 +1226,6 @@ int ubi_dbg_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len) int err; loff_t addr = (loff_t)pnum * ubi->peb_size + offset; - ubi_assert(!mutex_is_locked(&ubi->dbg_buf_mutex)); - mutex_lock(&ubi->dbg_buf_mutex); err = ubi->mtd->read(ubi->mtd, addr, len, &read, ubi->dbg_peb_buf); if (err && err != -EUCLEAN) { @@ -1273,74 +1256,4 @@ error: return err; } -/** - * paranoid_check_empty - whether a PEB is empty. - * @ubi: UBI device description object - * @pnum: the physical eraseblock number to check - * - * This function makes sure PEB @pnum is empty, which means it contains only - * %0xFF data bytes. Returns zero if the PEB is empty, %1 if not, and a - * negative error code in case of failure. - * - * Empty PEBs have the EC header, and do not have the VID header. The caller of - * this function should have already made sure the PEB does not have the VID - * header. However, this function re-checks that, because it is possible that - * the header and data has already been written to the PEB. - * - * Let's consider a possible scenario. Suppose there are 2 tasks - A and B. - * Task A is in 'wear_leveling_worker()'. It is reading VID header of PEB X to - * find which LEB it corresponds to. PEB X is currently unmapped, and has no - * VID header. Task B is trying to write to PEB X. - * - * Task A: in 'ubi_io_read_vid_hdr()': reads the VID header from PEB X. The - * read data contain all 0xFF bytes; - * Task B: writes VID header and some data to PEB X; - * Task A: assumes PEB X is empty, calls 'paranoid_check_empty()'. And if we - * do not re-read the VID header, and do not cancel the checking if it - * is there, we fail. - */ -static int paranoid_check_empty(struct ubi_device *ubi, int pnum) -{ - int err, offs = ubi->vid_hdr_aloffset, len = ubi->vid_hdr_alsize; - size_t read; - uint32_t magic; - const struct ubi_vid_hdr *vid_hdr; - - mutex_lock(&ubi->dbg_buf_mutex); - err = ubi->mtd->read(ubi->mtd, offs, len, &read, ubi->dbg_peb_buf); - if (err && err != -EUCLEAN) { - ubi_err("error %d while reading %d bytes from PEB %d:%d, " - "read %zd bytes", err, len, pnum, offs, read); - goto error; - } - - vid_hdr = ubi->dbg_peb_buf; - magic = be32_to_cpu(vid_hdr->magic); - if (magic == UBI_VID_HDR_MAGIC) - /* The PEB contains VID header, so it is not empty */ - goto out; - - err = check_pattern(ubi->dbg_peb_buf, 0xFF, len); - if (err == 0) { - ubi_err("flash region at PEB %d:%d, length %d does not " - "contain all 0xFF bytes", pnum, offs, len); - goto fail; - } - -out: - mutex_unlock(&ubi->dbg_buf_mutex); - return 0; - -fail: - ubi_err("paranoid check failed for PEB %d", pnum); - ubi_msg("hex dump of the %d-%d region", offs, offs + len); - print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, - ubi->dbg_peb_buf, len, 1); - err = 1; -error: - ubi_dbg_dump_stack(); - mutex_unlock(&ubi->dbg_buf_mutex); - return err; -} - #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */ diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c index e4be446e05e..600c7229d5c 100644 --- a/drivers/mtd/ubi/wl.c +++ b/drivers/mtd/ubi/wl.c @@ -463,7 +463,7 @@ retry: err = ubi_dbg_check_all_ff(ubi, e->pnum, ubi->vid_hdr_aloffset, ubi->peb_size - ubi->vid_hdr_aloffset); if (err) { - dbg_err("new PEB does not contain all 0xFF bytes"); + ubi_err("new PEB %d does not contain all 0xFF bytes", e->pnum); return err > 0 ? -EINVAL : err; } -- cgit v1.2.3-70-g09d2