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 <Artem.Bityutskiy@nokia.com>
diff --git a/drivers/mtd/ubi/debug.h b/drivers/mtd/ubi/debug.h
index 6fc7fda..a4da7a0 100644
--- a/drivers/mtd/ubi/debug.h
+++ b/drivers/mtd/ubi/debug.h
@@ -173,6 +173,7 @@
#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 6c5441e..c8edbfd 100644
--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -98,14 +98,12 @@
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 @@
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 @@
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 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 @@
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 e4be446..600c722 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -463,7 +463,7 @@
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;
}