Merge tag 'upstream-4.1-rc1' of git://git.infradead.org/linux-ubifs

Pull UBI/UBIFS updates from Richard Weinberger:
 "This pull request includes the following UBI/UBIFS changes:

   - powercut emulation for UBI
   - a huge update to UBI Fastmap
   - cleanups and bugfixes all over UBI and UBIFS"

* tag 'upstream-4.1-rc1' of git://git.infradead.org/linux-ubifs: (50 commits)
  UBI: power cut emulation for testing
  UBIFS: fix output format of INUM_WATERMARK
  UBI: Fastmap: Fall back to scanning mode after ECC error
  UBI: Fastmap: Remove is_fm_block()
  UBI: Fastmap: Add blank line after declarations
  UBI: Fastmap: Remove else after return.
  UBI: Fastmap: Introduce may_reserve_for_fm()
  UBI: Fastmap: Introduce ubi_fastmap_init()
  UBI: Fastmap: Wire up WL accessor functions
  UBI: Add accessor functions for WL data structures
  UBI: Move fastmap specific functions out of wl.c
  UBI: Fastmap: Add new module parameter fm_debug
  UBI: Fastmap: Make self_check_eba() depend on fastmap self checking
  UBI: Fastmap: Add self check to detect absent PEBs
  UBI: Fix stale pointers in ubi->lookuptbl
  UBI: Fastmap: Enhance fastmap checking
  UBI: Add initial support for fastmap self checks
  UBI: Fastmap: Rework fastmap error paths
  UBI: Fastmap: Prepare for variable sized fastmaps
  UBI: Fastmap: Locking updates
  ...

drivers/mtd/ubi/attach.c

@@ -410,7 +410,7 @@ int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
 		second_is_newer = !second_is_newer;
 	} else {
 		dbg_bld("PEB %d CRC is OK", pnum);
-		bitflips = !!err;
+		bitflips |= !!err;
 	}
 	mutex_unlock(&ubi->buf_mutex);
 
@@ -1301,6 +1301,30 @@ static int scan_all(struct ubi_device *ubi, struct ubi_attach_info *ai,
 	return err;
 }
 
+static struct ubi_attach_info *alloc_ai(void)
+{
+	struct ubi_attach_info *ai;
+
+	ai = kzalloc(sizeof(struct ubi_attach_info), GFP_KERNEL);
+	if (!ai)
+		return ai;
+
+	INIT_LIST_HEAD(&ai->corr);
+	INIT_LIST_HEAD(&ai->free);
+	INIT_LIST_HEAD(&ai->erase);
+	INIT_LIST_HEAD(&ai->alien);
+	ai->volumes = RB_ROOT;
+	ai->aeb_slab_cache = kmem_cache_create("ubi_aeb_slab_cache",
+					       sizeof(struct ubi_ainf_peb),
+					       0, 0, NULL);
+	if (!ai->aeb_slab_cache) {
+		kfree(ai);
+		ai = NULL;
+	}
+
+	return ai;
+}
+
 #ifdef CONFIG_MTD_UBI_FASTMAP
 
 /**
@@ -1313,7 +1337,7 @@ static int scan_all(struct ubi_device *ubi, struct ubi_attach_info *ai,
  * UBI_NO_FASTMAP denotes that no fastmap was found.
  * UBI_BAD_FASTMAP denotes that the found fastmap was invalid.
  */
-static int scan_fast(struct ubi_device *ubi, struct ubi_attach_info *ai)
+static int scan_fast(struct ubi_device *ubi, struct ubi_attach_info **ai)
 {
 	int err, pnum, fm_anchor = -1;
 	unsigned long long max_sqnum = 0;
@@ -1334,7 +1358,7 @@ static int scan_fast(struct ubi_device *ubi, struct ubi_attach_info *ai)
 		cond_resched();
 
 		dbg_gen("process PEB %d", pnum);
-		err = scan_peb(ubi, ai, pnum, &vol_id, &sqnum);
+		err = scan_peb(ubi, *ai, pnum, &vol_id, &sqnum);
 		if (err < 0)
 			goto out_vidh;
 
@@ -1350,7 +1374,12 @@ static int scan_fast(struct ubi_device *ubi, struct ubi_attach_info *ai)
 	if (fm_anchor < 0)
 		return UBI_NO_FASTMAP;
 
-	return ubi_scan_fastmap(ubi, ai, fm_anchor);
+	destroy_ai(*ai);
+	*ai = alloc_ai();
+	if (!*ai)
+		return -ENOMEM;
+
+	return ubi_scan_fastmap(ubi, *ai, fm_anchor);
 
 out_vidh:
 	ubi_free_vid_hdr(ubi, vidh);
@@ -1362,30 +1391,6 @@ static int scan_fast(struct ubi_device *ubi, struct ubi_attach_info *ai)
 
 #endif
 
-static struct ubi_attach_info *alloc_ai(const char *slab_name)
-{
-	struct ubi_attach_info *ai;
-
-	ai = kzalloc(sizeof(struct ubi_attach_info), GFP_KERNEL);
-	if (!ai)
-		return ai;
-
-	INIT_LIST_HEAD(&ai->corr);
-	INIT_LIST_HEAD(&ai->free);
-	INIT_LIST_HEAD(&ai->erase);
-	INIT_LIST_HEAD(&ai->alien);
-	ai->volumes = RB_ROOT;
-	ai->aeb_slab_cache = kmem_cache_create(slab_name,
-					       sizeof(struct ubi_ainf_peb),
-					       0, 0, NULL);
-	if (!ai->aeb_slab_cache) {
-		kfree(ai);
-		ai = NULL;
-	}
-
-	return ai;
-}
-
 /**
  * ubi_attach - attach an MTD device.
  * @ubi: UBI device descriptor
@@ -1399,7 +1404,7 @@ int ubi_attach(struct ubi_device *ubi, int force_scan)
 	int err;
 	struct ubi_attach_info *ai;
 
-	ai = alloc_ai("ubi_aeb_slab_cache");
+	ai = alloc_ai();
 	if (!ai)
 		return -ENOMEM;
 
@@ -1413,11 +1418,11 @@ int ubi_attach(struct ubi_device *ubi, int force_scan)
 	if (force_scan)
 		err = scan_all(ubi, ai, 0);
 	else {
-		err = scan_fast(ubi, ai);
-		if (err > 0) {
+		err = scan_fast(ubi, &ai);
+		if (err > 0 || mtd_is_eccerr(err)) {
 			if (err != UBI_NO_FASTMAP) {
 				destroy_ai(ai);
-				ai = alloc_ai("ubi_aeb_slab_cache2");
+				ai = alloc_ai();
 				if (!ai)
 					return -ENOMEM;
 
@@ -1453,10 +1458,10 @@ int ubi_attach(struct ubi_device *ubi, int force_scan)
 		goto out_wl;
 
 #ifdef CONFIG_MTD_UBI_FASTMAP
-	if (ubi->fm && ubi_dbg_chk_gen(ubi)) {
+	if (ubi->fm && ubi_dbg_chk_fastmap(ubi)) {
 		struct ubi_attach_info *scan_ai;
 
-		scan_ai = alloc_ai("ubi_ckh_aeb_slab_cache");
+		scan_ai = alloc_ai();
 		if (!scan_ai) {
 			err = -ENOMEM;
 			goto out_wl;

drivers/mtd/ubi/build.c

@@ -81,6 +81,7 @@ static struct mtd_dev_param __initdata mtd_dev_param[UBI_MAX_DEVICES];
 #ifdef CONFIG_MTD_UBI_FASTMAP
 /* UBI module parameter to enable fastmap automatically on non-fastmap images */
 static bool fm_autoconvert;
+static bool fm_debug;
 #endif
 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
 struct class *ubi_class;
@@ -154,23 +155,22 @@ static struct device_attribute dev_mtd_num =
  */
 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
 {
+	int ret;
 	struct ubi_notification nt;
 
 	ubi_do_get_device_info(ubi, &nt.di);
 	ubi_do_get_volume_info(ubi, vol, &nt.vi);
 
-#ifdef CONFIG_MTD_UBI_FASTMAP
 	switch (ntype) {
 	case UBI_VOLUME_ADDED:
 	case UBI_VOLUME_REMOVED:
 	case UBI_VOLUME_RESIZED:
 	case UBI_VOLUME_RENAMED:
-		if (ubi_update_fastmap(ubi)) {
-			ubi_err(ubi, "Unable to update fastmap!");
-			ubi_ro_mode(ubi);
-		}
+		ret = ubi_update_fastmap(ubi);
+		if (ret)
+			ubi_msg(ubi, "Unable to write a new fastmap: %i", ret);
 	}
-#endif
+
 	return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
 }
 
@@ -950,8 +950,10 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
 	if (ubi->fm_pool.max_size < UBI_FM_MIN_POOL_SIZE)
 		ubi->fm_pool.max_size = UBI_FM_MIN_POOL_SIZE;
 
-	ubi->fm_wl_pool.max_size = UBI_FM_WL_POOL_SIZE;
+	ubi->fm_wl_pool.max_size = ubi->fm_pool.max_size / 2;
 	ubi->fm_disabled = !fm_autoconvert;
+	if (fm_debug)
+		ubi_enable_dbg_chk_fastmap(ubi);
 
 	if (!ubi->fm_disabled && (int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd)
 	    <= UBI_FM_MAX_START) {
@@ -970,8 +972,8 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
 	mutex_init(&ubi->ckvol_mutex);
 	mutex_init(&ubi->device_mutex);
 	spin_lock_init(&ubi->volumes_lock);
-	mutex_init(&ubi->fm_mutex);
-	init_rwsem(&ubi->fm_sem);
+	init_rwsem(&ubi->fm_protect);
+	init_rwsem(&ubi->fm_eba_sem);
 
 	ubi_msg(ubi, "attaching mtd%d", mtd->index);
 
@@ -1115,8 +1117,11 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway)
 	ubi_msg(ubi, "detaching mtd%d", ubi->mtd->index);
 #ifdef CONFIG_MTD_UBI_FASTMAP
 	/* If we don't write a new fastmap at detach time we lose all
-	 * EC updates that have been made since the last written fastmap. */
-	ubi_update_fastmap(ubi);
+	 * EC updates that have been made since the last written fastmap.
+	 * In case of fastmap debugging we omit the update to simulate an
+	 * unclean shutdown. */
+	if (!ubi_dbg_chk_fastmap(ubi))
+		ubi_update_fastmap(ubi);
 #endif
 	/*
 	 * Before freeing anything, we have to stop the background thread to
@@ -1501,6 +1506,8 @@ MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: mtd=<name|num|pa
 #ifdef CONFIG_MTD_UBI_FASTMAP
 module_param(fm_autoconvert, bool, 0644);
 MODULE_PARM_DESC(fm_autoconvert, "Set this parameter to enable fastmap automatically on images without a fastmap.");
+module_param(fm_debug, bool, 0);
+MODULE_PARM_DESC(fm_debug, "Set this parameter to enable fastmap debugging by default. Warning, this will make fastmap slow!");
 #endif
 MODULE_VERSION(__stringify(UBI_VERSION));
 MODULE_DESCRIPTION("UBI - Unsorted Block Images");

drivers/mtd/ubi/cdev.c

@@ -455,7 +455,7 @@ static long vol_cdev_ioctl(struct file *file, unsigned int cmd,
 		/* Validate the request */
 		err = -EINVAL;
 		if (req.lnum < 0 || req.lnum >= vol->reserved_pebs ||
-		    req.bytes < 0 || req.lnum >= vol->usable_leb_size)
+		    req.bytes < 0 || req.bytes > vol->usable_leb_size)
 			break;
 
 		err = get_exclusive(desc);

drivers/mtd/ubi/debug.c

@@ -263,7 +263,7 @@ static ssize_t dfs_file_read(struct file *file, char __user *user_buf,
 	struct dentry *dent = file->f_path.dentry;
 	struct ubi_device *ubi;
 	struct ubi_debug_info *d;
-	char buf[3];
+	char buf[8];
 	int val;
 
 	ubi = ubi_get_device(ubi_num);
@@ -275,12 +275,30 @@ static ssize_t dfs_file_read(struct file *file, char __user *user_buf,
 		val = d->chk_gen;
 	else if (dent == d->dfs_chk_io)
 		val = d->chk_io;
+	else if (dent == d->dfs_chk_fastmap)
+		val = d->chk_fastmap;
 	else if (dent == d->dfs_disable_bgt)
 		val = d->disable_bgt;
 	else if (dent == d->dfs_emulate_bitflips)
 		val = d->emulate_bitflips;
 	else if (dent == d->dfs_emulate_io_failures)
 		val = d->emulate_io_failures;
+	else if (dent == d->dfs_emulate_power_cut) {
+		snprintf(buf, sizeof(buf), "%u\n", d->emulate_power_cut);
+		count = simple_read_from_buffer(user_buf, count, ppos,
+						buf, strlen(buf));
+		goto out;
+	} else if (dent == d->dfs_power_cut_min) {
+		snprintf(buf, sizeof(buf), "%u\n", d->power_cut_min);
+		count = simple_read_from_buffer(user_buf, count, ppos,
+						buf, strlen(buf));
+		goto out;
+	} else if (dent == d->dfs_power_cut_max) {
+		snprintf(buf, sizeof(buf), "%u\n", d->power_cut_max);
+		count = simple_read_from_buffer(user_buf, count, ppos,
+						buf, strlen(buf));
+		goto out;
+	}
 	else {
 		count = -EINVAL;
 		goto out;
@@ -309,7 +327,7 @@ static ssize_t dfs_file_write(struct file *file, const char __user *user_buf,
 	struct ubi_device *ubi;
 	struct ubi_debug_info *d;
 	size_t buf_size;
-	char buf[8];
+	char buf[8] = {0};
 	int val;
 
 	ubi = ubi_get_device(ubi_num);
@@ -323,6 +341,21 @@ static ssize_t dfs_file_write(struct file *file, const char __user *user_buf,
 		goto out;
 	}
 
+	if (dent == d->dfs_power_cut_min) {
+		if (kstrtouint(buf, 0, &d->power_cut_min) != 0)
+			count = -EINVAL;
+		goto out;
+	} else if (dent == d->dfs_power_cut_max) {
+		if (kstrtouint(buf, 0, &d->power_cut_max) != 0)
+			count = -EINVAL;
+		goto out;
+	} else if (dent == d->dfs_emulate_power_cut) {
+		if (kstrtoint(buf, 0, &val) != 0)
+			count = -EINVAL;
+		d->emulate_power_cut = val;
+		goto out;
+	}
+
 	if (buf[0] == '1')
 		val = 1;
 	else if (buf[0] == '0')
@@ -336,6 +369,8 @@ static ssize_t dfs_file_write(struct file *file, const char __user *user_buf,
 		d->chk_gen = val;
 	else if (dent == d->dfs_chk_io)
 		d->chk_io = val;
+	else if (dent == d->dfs_chk_fastmap)
+		d->chk_fastmap = val;
 	else if (dent == d->dfs_disable_bgt)
 		d->disable_bgt = val;
 	else if (dent == d->dfs_emulate_bitflips)
@@ -406,6 +441,13 @@ int ubi_debugfs_init_dev(struct ubi_device *ubi)
 		goto out_remove;
 	d->dfs_chk_io = dent;
 
+	fname = "chk_fastmap";
+	dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, (void *)ubi_num,
+				   &dfs_fops);
+	if (IS_ERR_OR_NULL(dent))
+		goto out_remove;
+	d->dfs_chk_fastmap = dent;
+
 	fname = "tst_disable_bgt";
 	dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, (void *)ubi_num,
 				   &dfs_fops);
@@ -427,6 +469,27 @@ int ubi_debugfs_init_dev(struct ubi_device *ubi)
 		goto out_remove;
 	d->dfs_emulate_io_failures = dent;
 
+	fname = "tst_emulate_power_cut";
+	dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, (void *)ubi_num,
+				   &dfs_fops);
+	if (IS_ERR_OR_NULL(dent))
+		goto out_remove;
+	d->dfs_emulate_power_cut = dent;
+
+	fname = "tst_emulate_power_cut_min";
+	dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, (void *)ubi_num,
+				   &dfs_fops);
+	if (IS_ERR_OR_NULL(dent))
+		goto out_remove;
+	d->dfs_power_cut_min = dent;
+
+	fname = "tst_emulate_power_cut_max";
+	dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, (void *)ubi_num,
+				   &dfs_fops);
+	if (IS_ERR_OR_NULL(dent))
+		goto out_remove;
+	d->dfs_power_cut_max = dent;
+
 	return 0;
 
 out_remove:
@@ -447,3 +510,36 @@ void ubi_debugfs_exit_dev(struct ubi_device *ubi)
 	if (IS_ENABLED(CONFIG_DEBUG_FS))
 		debugfs_remove_recursive(ubi->dbg.dfs_dir);
 }
+
+/**
+ * ubi_dbg_power_cut - emulate a power cut if it is time to do so
+ * @ubi: UBI device description object
+ * @caller: Flags set to indicate from where the function is being called
+ *
+ * Returns non-zero if a power cut was emulated, zero if not.
+ */
+int ubi_dbg_power_cut(struct ubi_device *ubi, int caller)
+{
+	unsigned int range;
+
+	if ((ubi->dbg.emulate_power_cut & caller) == 0)
+		return 0;
+
+	if (ubi->dbg.power_cut_counter == 0) {
+		ubi->dbg.power_cut_counter = ubi->dbg.power_cut_min;
+
+		if (ubi->dbg.power_cut_max > ubi->dbg.power_cut_min) {
+			range = ubi->dbg.power_cut_max - ubi->dbg.power_cut_min;
+			ubi->dbg.power_cut_counter += prandom_u32() % range;
+		}
+		return 0;
+	}
+
+	ubi->dbg.power_cut_counter--;
+	if (ubi->dbg.power_cut_counter)
+		return 0;
+
+	ubi_msg(ubi, "XXXXXXXXXXXXXXX emulating a power cut XXXXXXXXXXXXXXXX");
+	ubi_ro_mode(ubi);
+	return 1;
+}