Merge git://git.infradead.org/ubi-2.6

* git://git.infradead.org/ubi-2.6:
UBI: add write checking
UBI: simplify debugging return codes
UBI: fix attaching error path
UBI: support attaching by MTD character device name
UBI: mark few variables as __initdata

drivers/mtd/ubi/build.c

···
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/stringify.h>
+#include <linux/namei.h>
 #include <linux/stat.h>
 #include <linux/miscdevice.h>
 #include <linux/log2.h>
···
 
 /**
  * struct mtd_dev_param - MTD device parameter description data structure.
- * @name: MTD device name or number string
+ * @name: MTD character device node path, MTD device name, or MTD device number
+ *        string
  * @vid_hdr_offs: VID header offset
  */
 struct mtd_dev_param {
···
 };
 
 /* Numbers of elements set in the @mtd_dev_param array */
-static int mtd_devs;
+static int __initdata mtd_devs;
 
 /* MTD devices specification parameters */
-static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
+static struct mtd_dev_param __initdata mtd_dev_param[UBI_MAX_DEVICES];
 
 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
 struct class *ubi_class;
···
 /**
  * ubi_sysfs_init - initialize sysfs for an UBI device.
  * @ubi: UBI device description object
+ * @ref: set to %1 on exit in case of failure if a reference to @ubi->dev was
+ *       taken
  *
  * This function returns zero in case of success and a negative error code in
  * case of failure.
  */
-static int ubi_sysfs_init(struct ubi_device *ubi)
+static int ubi_sysfs_init(struct ubi_device *ubi, int *ref)
 {
 	int err;
 
···
 	if (err)
 		return err;
 
+	*ref = 1;
 	err = device_create_file(&ubi->dev, &dev_eraseblock_size);
 	if (err)
 		return err;
···
 }
 
 /**
- * kill_volumes - destroy all volumes.
+ * kill_volumes - destroy all user volumes.
  * @ubi: UBI device description object
  */
 static void kill_volumes(struct ubi_device *ubi)
···
 }
 
 /**
- * free_user_volumes - free all user volumes.
- * @ubi: UBI device description object
- *
- * Normally the volumes are freed at the release function of the volume device
- * objects. However, on error paths the volumes have to be freed before the
- * device objects have been initialized.
- */
-static void free_user_volumes(struct ubi_device *ubi)
-{
-	int i;
-
-	for (i = 0; i < ubi->vtbl_slots; i++)
-		if (ubi->volumes[i]) {
-			kfree(ubi->volumes[i]->eba_tbl);
-			kfree(ubi->volumes[i]);
-		}
-}
-
-/**
  * uif_init - initialize user interfaces for an UBI device.
  * @ubi: UBI device description object
+ * @ref: set to %1 on exit in case of failure if a reference to @ubi->dev was
+ *       taken, otherwise set to %0
+ *
+ * This function initializes various user interfaces for an UBI device. If the
+ * initialization fails at an early stage, this function frees all the
+ * resources it allocated, returns an error, and @ref is set to %0. However,
+ * if the initialization fails after the UBI device was registered in the
+ * driver core subsystem, this function takes a reference to @ubi->dev, because
+ * otherwise the release function ('dev_release()') would free whole @ubi
+ * object. The @ref argument is set to %1 in this case. The caller has to put
+ * this reference.
  *
  * This function returns zero in case of success and a negative error code in
- * case of failure. Note, this function destroys all volumes if it fails.
+ * case of failure.
  */
-static int uif_init(struct ubi_device *ubi)
+static int uif_init(struct ubi_device *ubi, int *ref)
 {
 	int i, err;
 	dev_t dev;
 
+	*ref = 0;
 	sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
 
 	/*
···
 		goto out_unreg;
 	}
 
-	err = ubi_sysfs_init(ubi);
+	err = ubi_sysfs_init(ubi, ref);
 	if (err)
 		goto out_sysfs;
 
···
 out_volumes:
 	kill_volumes(ubi);
 out_sysfs:
+	if (*ref)
+		get_device(&ubi->dev);
 	ubi_sysfs_close(ubi);
 	cdev_del(&ubi->cdev);
 out_unreg:
···
 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
 {
 	struct ubi_device *ubi;
-	int i, err, do_free = 1;
+	int i, err, ref = 0;
 
 	/*
 	 * Check if we already have the same MTD device attached.
···
 			goto out_detach;
 	}
 
-	err = uif_init(ubi);
+	err = uif_init(ubi, &ref);
 	if (err)
-		goto out_nofree;
+		goto out_detach;
 
 	ubi->bgt_thread = kthread_create(ubi_thread, ubi, ubi->bgt_name);
 	if (IS_ERR(ubi->bgt_thread)) {
···
 
 out_uif:
 	uif_close(ubi);
-out_nofree:
-	do_free = 0;
 out_detach:
 	ubi_wl_close(ubi);
-	if (do_free)
-		free_user_volumes(ubi);
 	free_internal_volumes(ubi);
 	vfree(ubi->vtbl);
 out_free:
···
 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
 	vfree(ubi->dbg_peb_buf);
 #endif
-	kfree(ubi);
+	if (ref)
+		put_device(&ubi->dev);
+	else
+		kfree(ubi);
 	return err;
 }
 
···
 
 	/*
 	 * Get a reference to the device in order to prevent 'dev_release()'
-	 * from freeing @ubi object.
+	 * from freeing the @ubi object.
 	 */
 	get_device(&ubi->dev);
 
···
 }
 
 /**
- * find_mtd_device - open an MTD device by its name or number.
- * @mtd_dev: name or number of the device
+ * open_mtd_by_chdev - open an MTD device by its character device node path.
+ * @mtd_dev: MTD character device node path
+ *
+ * This helper function opens an MTD device by its character node device path.
+ * Returns MTD device description object in case of success and a negative
+ * error code in case of failure.
+ */
+static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev)
+{
+	int err, major, minor, mode;
+	struct path path;
+
+	/* Probably this is an MTD character device node path */
+	err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);
+	if (err)
+		return ERR_PTR(err);
+
+	/* MTD device number is defined by the major / minor numbers */
+	major = imajor(path.dentry->d_inode);
+	minor = iminor(path.dentry->d_inode);
+	mode = path.dentry->d_inode->i_mode;
+	path_put(&path);
+	if (major != MTD_CHAR_MAJOR || !S_ISCHR(mode))
+		return ERR_PTR(-EINVAL);
+
+	if (minor & 1)
+		/*
+		 * Just do not think the "/dev/mtdrX" devices support is need,
+		 * so do not support them to avoid doing extra work.
+		 */
+		return ERR_PTR(-EINVAL);
+
+	return get_mtd_device(NULL, minor / 2);
+}
+
+/**
+ * open_mtd_device - open MTD device by name, character device path, or number.
+ * @mtd_dev: name, character device node path, or MTD device device number
  *
  * This function tries to open and MTD device described by @mtd_dev string,
- * which is first treated as an ASCII number, and if it is not true, it is
- * treated as MTD device name. Returns MTD device description object in case of
- * success and a negative error code in case of failure.
+ * which is first treated as ASCII MTD device number, and if it is not true, it
+ * is treated as MTD device name, and if that is also not true, it is treated
+ * as MTD character device node path. Returns MTD device description object in
+ * case of success and a negative error code in case of failure.
  */
 static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
 {
···
 		 * MTD device name.
 		 */
 		mtd = get_mtd_device_nm(mtd_dev);
+		if (IS_ERR(mtd) && PTR_ERR(mtd) == -ENODEV)
+			/* Probably this is an MTD character device node path */
+			mtd = open_mtd_by_chdev(mtd_dev);
 	} else
 		mtd = get_mtd_device(NULL, mtd_num);
 
···
 
 module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000);
 MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: "
-		      "mtd=<name|num>[,<vid_hdr_offs>].\n"
+		      "mtd=<name|num|path>[,<vid_hdr_offs>].\n"
 		      "Multiple \"mtd\" parameters may be specified.\n"
-		      "MTD devices may be specified by their number or name.\n"
+		      "MTD devices may be specified by their number, name, or "
+		      "path to the MTD character device node.\n"
 		      "Optional \"vid_hdr_offs\" parameter specifies UBI VID "
-		      "header position and data starting position to be used "
-		      "by UBI.\n"
-		      "Example: mtd=content,1984 mtd=4 - attach MTD device"
+		      "header position to be used by UBI.\n"
+		      "Example 1: mtd=/dev/mtd0 - attach MTD device "
+		      "/dev/mtd0.\n"
+		      "Example 2: mtd=content,1984 mtd=4 - attach MTD device "
 		      "with name \"content\" using VID header offset 1984, and "
 		      "MTD device number 4 with default VID header offset.");
 

drivers/mtd/ubi/debug.h

···
 
 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
 int ubi_dbg_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len);
+int ubi_dbg_check_write(struct ubi_device *ubi, const void *buf, int pnum,
+			int offset, int len);
 #else
 #define ubi_dbg_check_all_ff(ubi, pnum, offset, len) 0
+#define ubi_dbg_check_write(ubi, buf, pnum, offset, len) 0
 #endif
 
 #ifdef CONFIG_MTD_UBI_DEBUG_DISABLE_BGT
···
 #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
+#define ubi_dbg_check_write(ubi, buf, pnum, offset, len) 0
 
 #endif /* !CONFIG_MTD_UBI_DEBUG */
 #endif /* !__UBI_DEBUG_H__ */

drivers/mtd/ubi/io.c

···
 
 	err = paranoid_check_not_bad(ubi, pnum);
 	if (err)
-		return err > 0 ? -EINVAL : err;
+		return err;
 
 	addr = (loff_t)pnum * ubi->peb_size + offset;
 retry:
···
 
 	err = paranoid_check_not_bad(ubi, pnum);
 	if (err)
-		return err > 0 ? -EINVAL : err;
+		return err;
 
 	/* The area we are writing to has to contain all 0xFF bytes */
 	err = ubi_dbg_check_all_ff(ubi, pnum, offset, len);
 	if (err)
-		return err > 0 ? -EINVAL : err;
+		return err;
 
 	if (offset >= ubi->leb_start) {
 		/*
···
 		 */
 		err = paranoid_check_peb_ec_hdr(ubi, pnum);
 		if (err)
-			return err > 0 ? -EINVAL : err;
+			return err;
 		err = paranoid_check_peb_vid_hdr(ubi, pnum);
 		if (err)
-			return err > 0 ? -EINVAL : err;
+			return err;
 	}
 
 	if (ubi_dbg_is_write_failure()) {
···
 		ubi_dbg_dump_flash(ubi, pnum, offset, len);
 	} else
 		ubi_assert(written == len);
+
+	if (!err) {
+		err = ubi_dbg_check_write(ubi, buf, pnum, offset, len);
+		if (err)
+			return err;
+
+		/*
+		 * Since we always write sequentially, the rest of the PEB has
+		 * to contain only 0xFF bytes.
+		 */
+		offset += len;
+		len = ubi->peb_size - offset;
+		if (len)
+			err = ubi_dbg_check_all_ff(ubi, pnum, offset, len);
+	}
 
 	return err;
 }
···
 
 	err = ubi_dbg_check_all_ff(ubi, pnum, 0, ubi->peb_size);
 	if (err)
-		return err > 0 ? -EINVAL : err;
+		return err;
 
 	if (ubi_dbg_is_erase_failure() && !err) {
 		dbg_err("cannot erase PEB %d (emulated)", pnum);
···
 
 	err = paranoid_check_not_bad(ubi, pnum);
 	if (err != 0)
-		return err > 0 ? -EINVAL : err;
+		return err;
 
 	if (ubi->ro_mode) {
 		ubi_err("read-only mode");
···
 
 	err = paranoid_check_ec_hdr(ubi, pnum, ec_hdr);
 	if (err)
-		return -EINVAL;
+		return err;
 
 	err = ubi_io_write(ubi, ec_hdr, pnum, 0, ubi->ec_hdr_alsize);
 	return err;
···
 
 	err = paranoid_check_peb_ec_hdr(ubi, pnum);
 	if (err)
-		return err > 0 ? -EINVAL : err;
+		return err;
 
 	vid_hdr->magic = cpu_to_be32(UBI_VID_HDR_MAGIC);
 	vid_hdr->version = UBI_VERSION;
···
 
 	err = paranoid_check_vid_hdr(ubi, pnum, vid_hdr);
 	if (err)
-		return -EINVAL;
+		return err;
 
 	p = (char *)vid_hdr - ubi->vid_hdr_shift;
 	err = ubi_io_write(ubi, p, pnum, ubi->vid_hdr_aloffset,
···
  * @ubi: UBI device description object
  * @pnum: physical eraseblock number to check
  *
- * This function returns zero if the physical eraseblock is good, a positive
- * number if it is bad and a negative error code if an error occurred.
+ * This function returns zero if the physical eraseblock is good, %-EINVAL if
+ * it is bad and a negative error code if an error occurred.
  */
 static int paranoid_check_not_bad(const struct ubi_device *ubi, int pnum)
 {
···
 
 	ubi_err("paranoid check failed for PEB %d", pnum);
 	ubi_dbg_dump_stack();
-	return err;
+	return err > 0 ? -EINVAL : err;
 }
 
 /**
···
  * @ec_hdr: the erase counter header to check
  *
  * This function returns zero if the erase counter header contains valid
- * values, and %1 if not.
+ * values, and %-EINVAL if not.
  */
 static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum,
 				 const struct ubi_ec_hdr *ec_hdr)
···
 fail:
 	ubi_dbg_dump_ec_hdr(ec_hdr);
 	ubi_dbg_dump_stack();
-	return 1;
+	return -EINVAL;
 }
 
 /**
···
  * @ubi: UBI device description object
  * @pnum: the physical eraseblock number to check
  *
- * This function returns zero if the erase counter header is all right, %1 if
- * not, and a negative error code if an error occurred.
+ * This function returns zero if the erase counter header is all right and and
+ * a negative error code if not or if an error occurred.
  */
 static int paranoid_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum)
 {
···
 		ubi_err("paranoid check failed for PEB %d", pnum);
 		ubi_dbg_dump_ec_hdr(ec_hdr);
 		ubi_dbg_dump_stack();
-		err = 1;
+		err = -EINVAL;
 		goto exit;
 	}
 
···
  * @vid_hdr: the volume identifier header to check
  *
  * This function returns zero if the volume identifier header is all right, and
- * %1 if not.
+ * %-EINVAL if not.
  */
 static int paranoid_check_vid_hdr(const struct ubi_device *ubi, int pnum,
 				  const struct ubi_vid_hdr *vid_hdr)
···
 	ubi_err("paranoid check failed for PEB %d", pnum);
 	ubi_dbg_dump_vid_hdr(vid_hdr);
 	ubi_dbg_dump_stack();
-	return 1;
+	return -EINVAL;
 
 }
 
···
  * @pnum: the physical eraseblock number to check
  *
  * This function returns zero if the volume identifier header is all right,
- * %1 if not, and a negative error code if an error occurred.
+ * and a negative error code if not or if an error occurred.
  */
 static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum)
 {
···
 		ubi_err("paranoid check failed for PEB %d", pnum);
 		ubi_dbg_dump_vid_hdr(vid_hdr);
 		ubi_dbg_dump_stack();
-		err = 1;
+		err = -EINVAL;
 		goto exit;
 	}
 
···
 }
 
 /**
+ * ubi_dbg_check_write - make sure write succeeded.
+ * @ubi: UBI device description object
+ * @buf: buffer with data which were written
+ * @pnum: physical eraseblock number the data were written to
+ * @offset: offset within the physical eraseblock the data were written to
+ * @len: how many bytes were written
+ *
+ * This functions reads data which were recently written and compares it with
+ * the original data buffer - the data have to match. Returns zero if the data
+ * match and a negative error code if not or in case of failure.
+ */
+int ubi_dbg_check_write(struct ubi_device *ubi, const void *buf, int pnum,
+			int offset, int len)
+{
+	int err, i;
+
+	mutex_lock(&ubi->dbg_buf_mutex);
+	err = ubi_io_read(ubi, ubi->dbg_peb_buf, pnum, offset, len);
+	if (err)
+		goto out_unlock;
+
+	for (i = 0; i < len; i++) {
+		uint8_t c = ((uint8_t *)buf)[i];
+		uint8_t c1 = ((uint8_t *)ubi->dbg_peb_buf)[i];
+		int dump_len;
+
+		if (c == c1)
+			continue;
+
+		ubi_err("paranoid check failed for PEB %d:%d, len %d",
+			pnum, offset, len);
+		ubi_msg("data differ at position %d", i);
+		dump_len = max_t(int, 128, len - i);
+		ubi_msg("hex dump of the original buffer from %d to %d",
+			i, i + dump_len);
+		print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
+			       buf + i, dump_len, 1);
+		ubi_msg("hex dump of the read buffer from %d to %d",
+			i, i + dump_len);
+		print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
+			       ubi->dbg_peb_buf + i, dump_len, 1);
+		ubi_dbg_dump_stack();
+		err = -EINVAL;
+		goto out_unlock;
+	}
+	mutex_unlock(&ubi->dbg_buf_mutex);
+
+	return 0;
+
+out_unlock:
+	mutex_unlock(&ubi->dbg_buf_mutex);
+	return err;
+}
+
+/**
  * 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
···
  * @len: the length of the region to check
  *
  * This function returns zero if only 0xFF bytes are present at offset
- * @offset of the physical eraseblock @pnum, %1 if not, and a negative error
- * code if an error occurred.
+ * @offset of the physical eraseblock @pnum, and a negative error code if not
+ * or if an error occurred.
  */
 int ubi_dbg_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len)
 {
···
 	ubi_msg("hex dump of the %d-%d region", offset, offset + len);
 	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
 		       ubi->dbg_peb_buf, len, 1);
-	err = 1;
+	err = -EINVAL;
 error:
 	ubi_dbg_dump_stack();
 	mutex_unlock(&ubi->dbg_buf_mutex);

drivers/mtd/ubi/scan.c

···
 			seb->ec = si->mean_ec;
 
 	err = paranoid_check_si(ubi, si);
-	if (err) {
-		if (err > 0)
-			err = -EINVAL;
+	if (err)
 		goto out_vidh;
-	}
 
 	ubi_free_vid_hdr(ubi, vidh);
 	kfree(ech);
···
  * @ubi: UBI device description object
  * @si: scanning information
  *
- * This function returns zero if the scanning information is all right, %1 if
- * not and a negative error code if an error occurred.
+ * This function returns zero if the scanning information is all right, and a
+ * negative error code if not or if an error occurred.
  */
 static int paranoid_check_si(struct ubi_device *ubi, struct ubi_scan_info *si)
 {
···
 
 out:
 	ubi_dbg_dump_stack();
-	return 1;
+	return -EINVAL;
 }
 
 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */

drivers/mtd/ubi/wl.c

···
 				   ubi->peb_size - ubi->vid_hdr_aloffset);
 	if (err) {
 		ubi_err("new PEB %d does not contain all 0xFF bytes", e->pnum);
-		return err > 0 ? -EINVAL : err;
+		return err;
 	}
 
 	return e->pnum;
···
 	dbg_wl("erase PEB %d, old EC %llu", e->pnum, ec);
 
 	err = paranoid_check_ec(ubi, e->pnum, e->ec);
-	if (err > 0)
+	if (err)
 		return -EINVAL;
 
 	ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS);
···
  * @ec: the erase counter to check
  *
  * This function returns zero if the erase counter of physical eraseblock @pnum
- * is equivalent to @ec, %1 if not, and a negative error code if an error
- * occurred.
+ * is equivalent to @ec, and a negative error code if not or if an error occurred.
  */
 static int paranoid_check_ec(struct ubi_device *ubi, int pnum, int ec)
 {
···
  * @e: the wear-leveling entry to check
  * @root: the root of the tree
  *
- * This function returns zero if @e is in the @root RB-tree and %1 if it is
- * not.
+ * This function returns zero if @e is in the @root RB-tree and %-EINVAL if it
+ * is not.
  */
 static int paranoid_check_in_wl_tree(struct ubi_wl_entry *e,
 				     struct rb_root *root)
···
 	ubi_err("paranoid check failed for PEB %d, EC %d, RB-tree %p ",
 		e->pnum, e->ec, root);
 	ubi_dbg_dump_stack();
-	return 1;
+	return -EINVAL;
 }
 
 /**
···
  * @ubi: UBI device description object
  * @e: the wear-leveling entry to check
  *
- * This function returns zero if @e is in @ubi->pq and %1 if it is not.
+ * This function returns zero if @e is in @ubi->pq and %-EINVAL if it is not.
  */
 static int paranoid_check_in_pq(struct ubi_device *ubi, struct ubi_wl_entry *e)
 {
···
 	ubi_err("paranoid check failed for PEB %d, EC %d, Protect queue",
 		e->pnum, e->ec);
 	ubi_dbg_dump_stack();
-	return 1;
+	return -EINVAL;
 }
 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */