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 <Artem.Bityutskiy@nokia.com>

diff --git a/drivers/mtd/ubi/debug.h b/drivers/mtd/ubi/debug.h
index 13777e5beac93344ae759aa2ea0176c796e97d1d..6fc7fda2ab91794ae19bc1332c7637da6092b492 100644 (file)
--- 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

diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
index effaff28bab18ef4936c69cf354a4b8a11db17dd..6c5441e8791da4bfa101f3420f67be335287f6c2 100644 (file)
--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -98,8 +98,6 @@ 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_all_ff(struct ubi_device *ubi, int pnum, int offset,
-                                int len);
 static int paranoid_check_empty(struct ubi_device *ubi, int pnum);
 #else
 #define paranoid_check_not_bad(ubi, pnum) 0
@@ -107,7 +105,6 @@ static int paranoid_check_empty(struct ubi_device *ubi, int pnum);
 #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_all_ff(ubi, pnum, offset, len) 0
 #define paranoid_check_empty(ubi, pnum) 0
 #endif
 
@@ -244,7 +241,7 @@ int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
                return err > 0 ? -EINVAL : err;
 
        /* The area we are writing to has to contain all 0xFF bytes */
-       err = paranoid_check_all_ff(ubi, pnum, offset, len);
+       err = ubi_dbg_check_all_ff(ubi, pnum, offset, len);
        if (err)
                return err > 0 ? -EINVAL : err;
 
@@ -350,7 +347,7 @@ retry:
                return -EIO;
        }
 
-       err = paranoid_check_all_ff(ubi, pnum, 0, ubi->peb_size);
+       err = ubi_dbg_check_all_ff(ubi, pnum, 0, ubi->peb_size);
        if (err)
                return err > 0 ? -EINVAL : err;
 
@@ -672,8 +669,7 @@ 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 = paranoid_check_all_ff(ubi, pnum, 0,
-                                                   ubi->peb_size);
+                       err = ubi_dbg_check_all_ff(ubi, pnum, 0, ubi->peb_size);
                        if (err)
                                return err > 0 ? UBI_IO_BAD_EC_HDR : err;
 
@@ -1229,7 +1225,7 @@ exit:
 }
 
 /**
- * paranoid_check_all_ff - check that a region of flash is empty.
+ * ubi_dbg_check_all_ff - check that a region of flash is empty.
  * @ubi: UBI device description object
  * @pnum: the physical eraseblock number to check
  * @offset: the starting offset within the physical eraseblock to check
@@ -1239,13 +1235,14 @@ exit:
  * @offset of the physical eraseblock @pnum, %1 if not, and a negative error
  * code if an error occurred.
  */
-static int paranoid_check_all_ff(struct ubi_device *ubi, int pnum, int offset,
-                                int len)
+int ubi_dbg_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len)
 {
        size_t read;
        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) {

diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 2b2472300610f166eb897a53647436f4307c9456..e4be446e05ed61d29dfb6cdf04e0fd0174c40765 100644 (file)
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -459,6 +459,14 @@ retry:
        dbg_wl("PEB %d EC %d", e->pnum, e->ec);
        prot_queue_add(ubi, e);
        spin_unlock(&ubi->wl_lock);
+
+       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");
+               return err > 0 ? -EINVAL : err;
+       }
+
        return e->pnum;
 }