diff options
author | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2010-09-03 14:22:17 +0300 |
---|---|---|
committer | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2010-10-19 17:19:56 +0300 |
commit | 92e1a7d9e7e07fb1cf0cbbcdf202938d0819b54d (patch) | |
tree | 48930121fa2f1cf9ebd36f85118fe433d1ecd01f /drivers/mtd/ubi/io.c | |
parent | 74d82d2660058e32644f0c673656b2a1d01d3688 (diff) | |
download | linux-92e1a7d9e7e07fb1cf0cbbcdf202938d0819b54d.tar.bz2 |
UBI: handle bit-flips when no header found
Currently UBI has one small flaw - when we read EC or VID header, but find only
0xFF bytes, we return UBI_IO_FF and do not report whether we had bit-flips or
not. In case of the VID header, the scanning code adds this PEB to the free list,
even though there were bit-flips.
Imagine the following situation: we start writing VID header to a PEB and have a
power cut, so the PEB becomes unstable. When we scan and read the PEB, we get
a bit-flip. Currently, UBI would just ignore this and treat the PEB as free. This
patch changes UBI behavior and now UBI will schedule this PEB for erasure.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Diffstat (limited to 'drivers/mtd/ubi/io.c')
-rw-r--r-- | drivers/mtd/ubi/io.c | 54 |
1 files changed, 30 insertions, 24 deletions
diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c index 1677a215af64..b76252465c87 100644 --- a/drivers/mtd/ubi/io.c +++ b/drivers/mtd/ubi/io.c @@ -720,16 +720,16 @@ bad: int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum, struct ubi_ec_hdr *ec_hdr, int verbose) { - int err, read_err = 0; + int err, read_err; uint32_t crc, magic, hdr_crc; dbg_io("read EC header from PEB %d", pnum); ubi_assert(pnum >= 0 && pnum < ubi->peb_count); - err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE); - if (err) { - if (err != UBI_IO_BITFLIPS && err != -EBADMSG) - return err; + read_err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE); + if (read_err) { + if (read_err != UBI_IO_BITFLIPS && read_err != -EBADMSG) + return read_err; /* * We read all the data, but either a correctable bit-flip @@ -740,14 +740,12 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum, * this. If the EC header is still OK, we just report this as * there was a bit-flip, to force scrubbing. */ - if (err == -EBADMSG) - read_err = UBI_IO_BAD_HDR_EBADMSG; } magic = be32_to_cpu(ec_hdr->magic); if (magic != UBI_EC_HDR_MAGIC) { - if (read_err) - return read_err; + if (read_err == -EBADMSG) + return UBI_IO_BAD_HDR_EBADMSG; /* * The magic field is wrong. Let's check if we have read all @@ -762,7 +760,10 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum, else if (UBI_IO_DEBUG) dbg_msg("no EC header found at PEB %d, " "only 0xFF bytes", pnum); - return UBI_IO_FF; + if (!read_err) + return UBI_IO_FF; + else + return UBI_IO_FF_BITFLIPS; } /* @@ -790,7 +791,11 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum, } else if (UBI_IO_DEBUG) dbg_msg("bad EC header CRC at PEB %d, calculated " "%#08x, read %#08x", pnum, crc, hdr_crc); - return read_err ?: UBI_IO_BAD_HDR; + + if (!read_err) + return UBI_IO_BAD_HDR; + else + return UBI_IO_BAD_HDR_EBADMSG; } /* And of course validate what has just been read from the media */ @@ -986,7 +991,7 @@ bad: int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum, struct ubi_vid_hdr *vid_hdr, int verbose) { - int err, read_err = 0; + int err, read_err; uint32_t crc, magic, hdr_crc; void *p; @@ -994,20 +999,15 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum, ubi_assert(pnum >= 0 && pnum < ubi->peb_count); p = (char *)vid_hdr - ubi->vid_hdr_shift; - err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset, + read_err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset, ubi->vid_hdr_alsize); - if (err) { - if (err != UBI_IO_BITFLIPS && err != -EBADMSG) - return err; - - if (err == -EBADMSG) - read_err = UBI_IO_BAD_HDR_EBADMSG; - } + if (read_err && read_err != UBI_IO_BITFLIPS && read_err != -EBADMSG) + return read_err; magic = be32_to_cpu(vid_hdr->magic); if (magic != UBI_VID_HDR_MAGIC) { - if (read_err) - return read_err; + if (read_err == -EBADMSG) + return UBI_IO_BAD_HDR_EBADMSG; if (check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) { if (verbose) @@ -1016,7 +1016,10 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum, else if (UBI_IO_DEBUG) dbg_msg("no VID header found at PEB %d, " "only 0xFF bytes", pnum); - return UBI_IO_FF; + if (!read_err) + return UBI_IO_FF; + else + return UBI_IO_FF_BITFLIPS; } if (verbose) { @@ -1040,7 +1043,10 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum, } else if (UBI_IO_DEBUG) dbg_msg("bad CRC at PEB %d, calculated %#08x, " "read %#08x", pnum, crc, hdr_crc); - return read_err ?: UBI_IO_BAD_HDR; + if (!read_err) + return UBI_IO_BAD_HDR; + else + return UBI_IO_BAD_HDR_EBADMSG; } err = validate_vid_hdr(ubi, vid_hdr); |