libmtd: add lock/unlock helpers

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

diff --git a/include/libmtd.h b/include/libmtd.h
index afaba4286191c650a5f61e4ef55855180c465993..e30c8a6ba0bb8746c86b5928d6dd0564ef5e5417 100644 (file)
--- a/include/libmtd.h
+++ b/include/libmtd.h
@@ -137,6 +137,30 @@ int mtd_get_dev_info(libmtd_t desc, const char *node, struct mtd_dev_info *mtd);
  */
 int mtd_get_dev_info1(libmtd_t desc, int mtd_num, struct mtd_dev_info *mtd);
 
+/**
+ * mtd_lock - lock eraseblocks.
+ * @desc: MTD library descriptor
+ * @mtd: MTD device description object
+ * @fd: MTD device node file descriptor
+ * @eb: eraseblock to lock
+ *
+ * This function locks eraseblock @eb. Returns %0 in case of success and %-1
+ * in case of failure.
+ */
+int mtd_lock(const struct mtd_dev_info *mtd, int fd, int eb);
+
+/**
+ * mtd_unlock - unlock eraseblocks.
+ * @desc: MTD library descriptor
+ * @mtd: MTD device description object
+ * @fd: MTD device node file descriptor
+ * @eb: eraseblock to lock
+ *
+ * This function unlocks eraseblock @eb. Returns %0 in case of success and %-1
+ * in case of failure.
+ */
+int mtd_unlock(const struct mtd_dev_info *mtd, int fd, int eb);
+
 /**
  * mtd_erase - erase an eraseblock.
  * @desc: MTD library descriptor

diff --git a/lib/libmtd.c b/lib/libmtd.c
index d57ae8f63a0cb80db1d1b309d8a82ce0e3fce849..1b3d597332a31c13c18b6faddb0ac8477907e1fc 100644 (file)
--- a/lib/libmtd.c
+++ b/lib/libmtd.c
@@ -802,6 +802,38 @@ static int mtd_valid_erase_block(const struct mtd_dev_info *mtd, int eb)
        return 0;
 }
 
+static int mtd_xlock(const struct mtd_dev_info *mtd, int fd, int eb, int req,
+                    const char *sreq)
+{
+       int ret;
+       struct erase_info_user ei;
+
+       ret = mtd_valid_erase_block(mtd, eb);
+       if (ret)
+               return ret;
+
+       ei.start = eb * mtd->eb_size;
+       ei.length = mtd->eb_size;
+
+       ret = ioctl(fd, req, &ei);
+       if (ret < 0)
+               return sys_errmsg("%s ioctl failed for eraseblock %d "
+                                 "(mtd%d)", sreq, eb, mtd->mtd_num);
+
+       return 0;
+}
+#define mtd_xlock(mtd, fd, eb, req) mtd_xlock(mtd, fd, eb, req, #req)
+
+int mtd_lock(const struct mtd_dev_info *mtd, int fd, int eb)
+{
+       return mtd_xlock(mtd, fd, eb, MEMLOCK);
+}
+
+int mtd_unlock(const struct mtd_dev_info *mtd, int fd, int eb)
+{
+       return mtd_xlock(mtd, fd, eb, MEMUNLOCK);
+}
+
 int mtd_erase(libmtd_t desc, const struct mtd_dev_info *mtd, int fd, int eb)
 {
        int ret;