Merge branch 'linux-next' of git://git.infradead.org/ubifs-2.6

59a7ac12 · Linus Torvalds <[email protected]> · 2011-07-22 13:09:35 -07:00

* 'linux-next' of git://git.infradead.org/ubifs-2.6: (32 commits)
  MAINTAINERS: change e-mail of Adrian Hunter
  UBIFS: fix master node recovery
  UBIFS: improve power cut emulation testing
  UBIFS: rename recovery testing variables
  UBIFS: remove custom list of superblocks
  UBIFS: stop re-defining UBI operations
  UBIFS: switch to I/O helpers
  UBIFS: switch to ubifs_leb_write
  UBIFS: switch to ubifs_leb_read
  UBIFS: introduce more I/O helpers
  UBIFS: always print stacktrace when switching to R/O mode
  UBIFS: remove unused and unneeded debugging function
  UBIFS: add global debugfs knobs
  UBIFS: introduce debugfs helpers
  UBIFS: re-arrange debugging code a bit
  UBIFS: be more informative in failure mode
  UBIFS: switch self-check knobs to debugfs
  UBIFS: lessen amount of debugging check types
  UBIFS: introduce helper functions for debugging checks and tests
  UBIFS: amend debugging inode size check function prototype
  ...

Commit: 59a7ac12110f27951c6f754b4e451a9df686aea9
Parents: f99b7880 · cc8f9b99

Merge commit. Changes below are compared with the first parent: f99b7880.

Changes

22 files changed · +978 −700

File	Status	Add	Del	Content
Documentation/filesystems/ubifs.txt	modified	+0	−28	View file
MAINTAINERS	modified	+2	−1	View file
fs/ubifs/commit.c	modified	+4	−4	View file
fs/ubifs/debug.c	modified	+502	−260	View file
fs/ubifs/debug.h	modified	+133	−108	View file
fs/ubifs/dir.c	modified	+9	−7	View file
fs/ubifs/file.c	modified	+1	−1	View file
fs/ubifs/io.c	modified	+135	−33	View file
fs/ubifs/log.c	modified	+2	−4	View file
fs/ubifs/lprops.c	modified	+4	−4	View file
fs/ubifs/lpt.c	modified	+20	−17	View file
fs/ubifs/lpt_commit.c	modified	+20	−20	View file
fs/ubifs/misc.h	modified	+23	−80	View file
fs/ubifs/orphan.c	modified	+1	−1	View file
fs/ubifs/recovery.c	modified	+22	−21	View file
fs/ubifs/replay.c	modified	+1	−2	View file
fs/ubifs/sb.c	modified	+3	−3	View file
fs/ubifs/scan.c	modified	+2	−2	View file
fs/ubifs/super.c	modified	+3	−3	View file
fs/ubifs/tnc.c	modified	+13	−13	View file
fs/ubifs/tnc_commit.c	modified	+63	−82	View file
fs/ubifs/ubifs.h	modified	+15	−6	View file

Only the first 600 diff lines are shown. Download the complete patch.

Documentation/filesystems/ubifs.txt

View file

diff --git a/Documentation/filesystems/ubifs.txt b/Documentation/filesystems/ubifs.txt
index 8e4fab6..a0a61d2 100644
--- a/Documentation/filesystems/ubifs.txt
+++ b/Documentation/filesystems/ubifs.txt
@@ -111,34 +111,6 @@ The following is an example of the kernel boot arguments to attach mtd0
 to UBI and mount volume "rootfs":
 ubi.mtd=0 root=ubi0:rootfs rootfstype=ubifs
 
-
-Module Parameters for Debugging
-===============================
-
-When UBIFS has been compiled with debugging enabled, there are 2 module
-parameters that are available to control aspects of testing and debugging.
-
-debug_chks	Selects extra checks that UBIFS can do while running:
-
-		Check					Flag value
-
-		General checks				1
-		Check Tree Node Cache (TNC)		2
-		Check indexing tree size		4
-		Check orphan area			8
-		Check old indexing tree			16
-		Check LEB properties (lprops)		32
-		Check leaf nodes and inodes		64
-
-debug_tsts	Selects a mode of testing, as follows:
-
-		Test mode				Flag value
-
-		Failure mode for recovery testing	4
-
-For example, set debug_chks to 3 to enable general and TNC checks.
-
-
 References
 ==========
 

MAINTAINERS

View file

diff --git a/MAINTAINERS b/MAINTAINERS
index 187282d..72b979d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1,4 +1,5 @@
 
+
 	List of maintainers and how to submit kernel changes
 
 Please try to follow the guidelines below.  This will make things
@@ -6321,7 +6322,7 @@ F:	drivers/scsi/u14-34f.c
 
 UBI FILE SYSTEM (UBIFS)
 M:	Artem Bityutskiy <[email protected]>
-M:	Adrian Hunter <[email protected]>
+M:	Adrian Hunter <[email protected]>
 L:	[email protected]
 T:	git git://git.infradead.org/ubifs-2.6.git
 W:	http://www.linux-mtd.infradead.org/doc/ubifs.html

fs/ubifs/commit.c

View file

diff --git a/fs/ubifs/commit.c b/fs/ubifs/commit.c
index 87cd0ea..fb3b5c8 100644
--- a/fs/ubifs/commit.c
+++ b/fs/ubifs/commit.c
@@ -78,7 +78,7 @@ static int nothing_to_commit(struct ubifs_info *c)
 	 * If the root TNC node is dirty, we definitely have something to
 	 * commit.
 	 */
-	if (c->zroot.znode && test_bit(DIRTY_ZNODE, &c->zroot.znode->flags))
+	if (c->zroot.znode && ubifs_zn_dirty(c->zroot.znode))
 		return 0;
 
 	/*
@@ -418,7 +418,7 @@ int ubifs_run_commit(struct ubifs_info *c)
 
 	spin_lock(&c->cs_lock);
 	if (c->cmt_state == COMMIT_BROKEN) {
-		err = -EINVAL;
+		err = -EROFS;
 		goto out;
 	}
 
@@ -444,7 +444,7 @@ int ubifs_run_commit(struct ubifs_info *c)
 	 * re-check it.
 	 */
 	if (c->cmt_state == COMMIT_BROKEN) {
-		err = -EINVAL;
+		err = -EROFS;
 		goto out_cmt_unlock;
 	}
 
@@ -576,7 +576,7 @@ int dbg_check_old_index(struct ubifs_info *c, struct ubifs_zbranch *zroot)
 	struct idx_node *i;
 	size_t sz;
 
-	if (!(ubifs_chk_flags & UBIFS_CHK_OLD_IDX))
+	if (!dbg_is_chk_index(c))
 		return 0;
 
 	INIT_LIST_HEAD(&list);

fs/ubifs/debug.c

View file

diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index 0bb2bce..eef109a 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -27,13 +27,12 @@
  * various local functions of those subsystems.
  */
 
-#define UBIFS_DBG_PRESERVE_UBI
-
-#include "ubifs.h"
 #include <linux/module.h>
-#include <linux/moduleparam.h>
 #include <linux/debugfs.h>
 #include <linux/math64.h>
+#include <linux/uaccess.h>
+#include <linux/random.h>
+#include "ubifs.h"
 
 #ifdef CONFIG_UBIFS_FS_DEBUG
 
@@ -42,15 +41,6 @@ DEFINE_SPINLOCK(dbg_lock);
 static char dbg_key_buf0[128];
 static char dbg_key_buf1[128];
 
-unsigned int ubifs_chk_flags;
-unsigned int ubifs_tst_flags;
-
-module_param_named(debug_chks, ubifs_chk_flags, uint, S_IRUGO | S_IWUSR);
-module_param_named(debug_tsts, ubifs_tst_flags, uint, S_IRUGO | S_IWUSR);
-
-MODULE_PARM_DESC(debug_chks, "Debug check flags");
-MODULE_PARM_DESC(debug_tsts, "Debug special test flags");
-
 static const char *get_key_fmt(int fmt)
 {
 	switch (fmt) {
@@ -91,6 +81,28 @@ static const char *get_key_type(int type)
 	}
 }
 
+static const char *get_dent_type(int type)
+{
+	switch (type) {
+	case UBIFS_ITYPE_REG:
+		return "file";
+	case UBIFS_ITYPE_DIR:
+		return "dir";
+	case UBIFS_ITYPE_LNK:
+		return "symlink";
+	case UBIFS_ITYPE_BLK:
+		return "blkdev";
+	case UBIFS_ITYPE_CHR:
+		return "char dev";
+	case UBIFS_ITYPE_FIFO:
+		return "fifo";
+	case UBIFS_ITYPE_SOCK:
+		return "socket";
+	default:
+		return "unknown/invalid type";
+	}
+}
+
 static void sprintf_key(const struct ubifs_info *c, const union ubifs_key *key,
 			char *buffer)
 {
@@ -234,9 +246,13 @@ static void dump_ch(const struct ubifs_ch *ch)
 	printk(KERN_DEBUG "\tlen            %u\n", le32_to_cpu(ch->len));
 }
 
-void dbg_dump_inode(const struct ubifs_info *c, const struct inode *inode)
+void dbg_dump_inode(struct ubifs_info *c, const struct inode *inode)
 {
 	const struct ubifs_inode *ui = ubifs_inode(inode);
+	struct qstr nm = { .name = NULL };
+	union ubifs_key key;
+	struct ubifs_dent_node *dent, *pdent = NULL;
+	int count = 2;
 
 	printk(KERN_DEBUG "Dump in-memory inode:");
 	printk(KERN_DEBUG "\tinode          %lu\n", inode->i_ino);
@@ -270,6 +286,32 @@ void dbg_dump_inode(const struct ubifs_info *c, const struct inode *inode)
 	printk(KERN_DEBUG "\tlast_page_read %lu\n", ui->last_page_read);
 	printk(KERN_DEBUG "\tread_in_a_row  %lu\n", ui->read_in_a_row);
 	printk(KERN_DEBUG "\tdata_len       %d\n", ui->data_len);
+
+	if (!S_ISDIR(inode->i_mode))
+		return;
+
+	printk(KERN_DEBUG "List of directory entries:\n");
+	ubifs_assert(!mutex_is_locked(&c->tnc_mutex));
+
+	lowest_dent_key(c, &key, inode->i_ino);
+	while (1) {
+		dent = ubifs_tnc_next_ent(c, &key, &nm);
+		if (IS_ERR(dent)) {
+			if (PTR_ERR(dent) != -ENOENT)
+				printk(KERN_DEBUG "error %ld\n", PTR_ERR(dent));
+			break;
+		}
+
+		printk(KERN_DEBUG "\t%d: %s (%s)\n",
+		       count++, dent->name, get_dent_type(dent->type));
+
+		nm.name = dent->name;
+		nm.len = le16_to_cpu(dent->nlen);
+		kfree(pdent);
+		pdent = dent;
+		key_read(c, &dent->key, &key);
+	}
+	kfree(pdent);
 }
 
 void dbg_dump_node(const struct ubifs_info *c, const void *node)
@@ -278,7 +320,7 @@ void dbg_dump_node(const struct ubifs_info *c, const void *node)
 	union ubifs_key key;
 	const struct ubifs_ch *ch = node;
 
-	if (dbg_failure_mode)
+	if (dbg_is_tst_rcvry(c))
 		return;
 
 	/* If the magic is incorrect, just hexdump the first bytes */
@@ -834,7 +876,7 @@ void dbg_dump_leb(const struct ubifs_info *c, int lnum)
 	struct ubifs_scan_node *snod;
 	void *buf;
 
-	if (dbg_failure_mode)
+	if (dbg_is_tst_rcvry(c))
 		return;
 
 	printk(KERN_DEBUG "(pid %d) start dumping LEB %d\n",
@@ -1080,6 +1122,7 @@ out:
 
 /**
  * dbg_check_synced_i_size - check synchronized inode size.
+ * @c: UBIFS file-system description object
  * @inode: inode to check
  *
  * If inode is clean, synchronized inode size has to be equivalent to current
@@ -1087,12 +1130,12 @@ out:
  * has to be locked). Returns %0 if synchronized inode size if correct, and
  * %-EINVAL if not.
  */
-int dbg_check_synced_i_size(struct inode *inode)
+int dbg_check_synced_i_size(const struct ubifs_info *c, struct inode *inode)
 {
 	int err = 0;
 	struct ubifs_inode *ui = ubifs_inode(inode);
 
-	if (!(ubifs_chk_flags & UBIFS_CHK_GEN))
+	if (!dbg_is_chk_gen(c))
 		return 0;
 	if (!S_ISREG(inode->i_mode))
 		return 0;
@@ -1125,7 +1168,7 @@ int dbg_check_synced_i_size(struct inode *inode)
  * Note, it is good idea to make sure the @dir->i_mutex is locked before
  * calling this function.
  */
-int dbg_check_dir_size(struct ubifs_info *c, const struct inode *dir)
+int dbg_check_dir(struct ubifs_info *c, const struct inode *dir)
 {
 	unsigned int nlink = 2;
 	union ubifs_key key;
@@ -1133,7 +1176,7 @@ int dbg_check_dir_size(struct ubifs_info *c, const struct inode *dir)
 	struct qstr nm = { .name = NULL };
 	loff_t size = UBIFS_INO_NODE_SZ;
 
-	if (!(ubifs_chk_flags & UBIFS_CHK_GEN))
+	if (!dbg_is_chk_gen(c))
 		return 0;
 
 	if (!S_ISDIR(dir->i_mode))
@@ -1167,12 +1210,14 @@ int dbg_check_dir_size(struct ubifs_info *c, const struct inode *dir)
 			  "but calculated size is %llu", dir->i_ino,
 			  (unsigned long long)i_size_read(dir),
 			  (unsigned long long)size);
+		dbg_dump_inode(c, dir);
 		dump_stack();
 		return -EINVAL;
 	}
 	if (dir->i_nlink != nlink) {
 		ubifs_err("directory inode %lu has nlink %u, but calculated "
 			  "nlink is %u", dir->i_ino, dir->i_nlink, nlink);
+		dbg_dump_inode(c, dir);
 		dump_stack();
 		return -EINVAL;
 	}
@@ -1489,7 +1534,7 @@ int dbg_check_tnc(struct ubifs_info *c, int extra)
 	long clean_cnt = 0, dirty_cnt = 0;
 	int err, last;
 
-	if (!(ubifs_chk_flags & UBIFS_CHK_TNC))
+	if (!dbg_is_chk_index(c))
 		return 0;
 
 	ubifs_assert(mutex_is_locked(&c->tnc_mutex));
@@ -1736,7 +1781,7 @@ int dbg_check_idx_size(struct ubifs_info *c, long long idx_size)
 	int err;
 	long long calc = 0;
 
-	if (!(ubifs_chk_flags & UBIFS_CHK_IDX_SZ))
+	if (!dbg_is_chk_index(c))
 		return 0;
 
 	err = dbg_walk_index(c, NULL, add_size, &calc);
@@ -2312,7 +2357,7 @@ int dbg_check_filesystem(struct ubifs_info *c)
 	int err;
 	struct fsck_data fsckd;
 
-	if (!(ubifs_chk_flags & UBIFS_CHK_FS))
+	if (!dbg_is_chk_fs(c))
 		return 0;
 
 	fsckd.inodes = RB_ROOT;
@@ -2347,7 +2392,7 @@ int dbg_check_data_nodes_order(struct ubifs_info *c, struct list_head *head)
 	struct list_head *cur;
 	struct ubifs_scan_node *sa, *sb;
 
-	if (!(ubifs_chk_flags & UBIFS_CHK_GEN))
+	if (!dbg_is_chk_gen(c))
 		return 0;
 
 	for (cur = head->next; cur->next != head; cur = cur->next) {
@@ -2414,7 +2459,7 @@ int dbg_check_nondata_nodes_order(struct ubifs_info *c, struct list_head *head)
 	struct list_head *cur;
 	struct ubifs_scan_node *sa, *sb;
 
-	if (!(ubifs_chk_flags & UBIFS_CHK_GEN))
+	if (!dbg_is_chk_gen(c))
 		return 0;
 
 	for (cur = head->next; cur->next != head; cur = cur->next) {
@@ -2491,214 +2536,141 @@ error_dump:
 	return 0;
 }
 
-int dbg_force_in_the_gaps(void)
+static inline int chance(unsigned int n, unsigned int out_of)
 {
-	if (!(ubifs_chk_flags & UBIFS_CHK_GEN))
-		return 0;
+	return !!((random32() % out_of) + 1 <= n);
 
-	return !(random32() & 7);
 }
 
-/* Failure mode for recovery testing */
-
-#define chance(n, d) (simple_rand() <= (n) * 32768LL / (d))
-
-struct failure_mode_info {
-	struct list_head list;
-	struct ubifs_info *c;
-};
-
-static LIST_HEAD(fmi_list);
-static DEFINE_SPINLOCK(fmi_lock);
-
-static unsigned int next;
-
-static int simple_rand(void)
-{
-	if (next == 0)
-		next = current->pid;
-	next = next * 1103515245 + 12345;
-	return (next >> 16) & 32767;
-}
-
-static void failure_mode_init(struct ubifs_info *c)
-{
-	struct failure_mode_info *fmi;
-
-	fmi = kmalloc(sizeof(struct failure_mode_info), GFP_NOFS);
-	if (!fmi) {
-		ubifs_err("Failed to register failure mode - no memory");
-		return;
-	}
-	fmi->c = c;
-	spin_lock(&fmi_lock);
-	list_add_tail(&fmi->list, &fmi_list);
-	spin_unlock(&fmi_lock);
-}
-
-static void failure_mode_exit(struct ubifs_info *c)
+static int power_cut_emulated(struct ubifs_info *c, int lnum, int write)
 {
-	struct failure_mode_info *fmi, *tmp;
-
-	spin_lock(&fmi_lock);
-	list_for_each_entry_safe(fmi, tmp, &fmi_list, list)
-		if (fmi->c == c) {
-			list_del(&fmi->list);
-			kfree(fmi);
-		}
-	spin_unlock(&fmi_lock);
-}
-
-static struct ubifs_info *dbg_find_info(struct ubi_volume_desc *desc)
-{
-	struct failure_mode_info *fmi;
-
-	spin_lock(&fmi_lock);
-	list_for_each_entry(fmi, &fmi_list, list)
-		if (fmi->c->ubi == desc) {
-			struct ubifs_info *c = fmi->c;
-
-			spin_unlock(&fmi_lock);
-			return c;
-		}
-	spin_unlock(&fmi_lock);
-	return NULL;
-}
-
-static int in_failure_mode(struct ubi_volume_desc *desc)
-{
-	struct ubifs_info *c = dbg_find_info(desc);
-
-	if (c && dbg_failure_mode)
-		return c->dbg->failure_mode;
-	return 0;
-}
+	struct ubifs_debug_info *d = c->dbg;
 
-static int do_fail(struct ubi_volume_desc *desc, int lnum, int write)
-{
-	struct ubifs_info *c = dbg_find_info(desc);
-	struct ubifs_debug_info *d;
+	ubifs_assert(dbg_is_tst_rcvry(c));
 
-	if (!c || !dbg_failure_mode)
-		return 0;
-	d = c->dbg;
-	if (d->failure_mode)
-		return 1;
-	if (!d->fail_cnt) {
-		/* First call - decide delay to failure */
+	if (!d->pc_cnt) {
+		/* First call - decide delay to the power cut */
 		if (chance(1, 2)) {
-			unsigned int delay = 1 << (simple_rand() >> 11);
+			unsigned long delay;
 
 			if (chance(1, 2)) {
-				d->fail_delay = 1;
-				d->fail_timeout = jiffies +
-						  msecs_to_jiffies(delay);
-				dbg_rcvry("failing after %ums", delay);
+				d->pc_delay = 1;
+				/* Fail withing 1 minute */
+				delay = random32() % 60000;
+				d->pc_timeout = jiffies;
+				d->pc_timeout += msecs_to_jiffies(delay);
+				ubifs_warn("failing after %lums", delay);
 			} else {
-				d->fail_delay = 2;
-				d->fail_cnt_max = delay;
-				dbg_rcvry("failing after %u calls", delay);
+				d->pc_delay = 2;
+				delay = random32() % 10000;
+				/* Fail within 10000 operations */
+				d->pc_cnt_max = delay;
+				ubifs_warn("failing after %lu calls", delay);
 			}
 		}
-		d->fail_cnt += 1;
+
+		d->pc_cnt += 1;
 	}
+
 	/* Determine if failure delay has expired */
-	if (d->fail_delay == 1) {
-		if (time_before(jiffies, d->fail_timeout))
+	if (d->pc_delay == 1 && time_before(jiffies, d->pc_timeout))
 			return 0;
-	} else if (d->fail_delay == 2)
-		if (d->fail_cnt++ < d->fail_cnt_max)
+	if (d->pc_delay == 2 && d->pc_cnt++ < d->pc_cnt_max)
 			return 0;
+
 	if (lnum == UBIFS_SB_LNUM) {
-		if (write) {
-			if (chance(1, 2))
-				return 0;
-		} else if (chance(19, 20))
+		if (write && chance(1, 2))
+			return 0;
+		if (chance(19, 20))
 			return 0;
-		dbg_rcvry("failing in super block LEB %d", lnum);
+		ubifs_warn("failing in super block LEB %d", lnum);
 	} else if (lnum == UBIFS_MST_LNUM || lnum == UBIFS_MST_LNUM + 1) {
 		if (chance(19, 20))
 			return 0;
-		dbg_rcvry("failing in master LEB %d", lnum);
+		ubifs_warn("failing in master LEB %d", lnum);
 	} else if (lnum >= UBIFS_LOG_LNUM && lnum <= c->log_last) {
-		if (write) {
-			if (chance(99, 100))
-				return 0;
-		} else if (chance(399, 400))
+		if (write && chance(99, 100))
 			return 0;
-		dbg_rcvry("failing in log LEB %d", lnum);
+		if (chance(399, 400))
+			return 0;
+		ubifs_warn("failing in log LEB %d", lnum);
 	} else if (lnum >= c->lpt_first && lnum <= c->lpt_last) {
-		if (write) {
-			if (chance(7, 8))
-				return 0;
-		} else if (chance(19, 20))
+		if (write && chance(7, 8))
 			return 0;
-		dbg_rcvry("failing in LPT LEB %d", lnum);
+		if (chance(19, 20))
+			return 0;
+		ubifs_warn("failing in LPT LEB %d", lnum);
 	} else if (lnum >= c->orph_first && lnum <= c->orph_last) {
-		if (write) {
-			if (chance(1, 2))
-				return 0;
-		} else if (chance(9, 10))
+		if (write && chance(1, 2))
+			return 0;
+		if (chance(9, 10))
 			return 0;
-		dbg_rcvry("failing in orphan LEB %d", lnum);
+		ubifs_warn("failing in orphan LEB %d", lnum);
 	} else if (lnum == c->ihead_lnum) {
 		if (chance(99, 100))
 			return 0;
-		dbg_rcvry("failing in index head LEB %d", lnum);
+		ubifs_warn("failing in index head LEB %d", lnum);
 	} else if (c->jheads && lnum == c->jheads[GCHD].wbuf.lnum) {
 		if (chance(9, 10))
 			return 0;
-		dbg_rcvry("failing in GC head LEB %d", lnum);
+		ubifs_warn("failing in GC head LEB %d", lnum);
 	} else if (write && !RB_EMPTY_ROOT(&c->buds) &&
 		   !ubifs_search_bud(c, lnum)) {
 		if (chance(19, 20))
 			return 0;
-		dbg_rcvry("failing in non-bud LEB %d", lnum);
+		ubifs_warn("failing in non-bud LEB %d", lnum);
 	} else if (c->cmt_state == COMMIT_RUNNING_BACKGROUND ||
 		   c->cmt_state == COMMIT_RUNNING_REQUIRED) {
 		if (chance(999, 1000))
 			return 0;
-		dbg_rcvry("failing in bud LEB %d commit running", lnum);
+		ubifs_warn("failing in bud LEB %d commit running", lnum);
 	} else {
 		if (chance(9999, 10000))
 			return 0;
-		dbg_rcvry("failing in bud LEB %d commit not running", lnum);
+		ubifs_warn("failing in bud LEB %d commit not running", lnum);
 	}
-	ubifs_err("*** SETTING FAILURE MODE ON (LEB %d) ***", lnum);
-	d->failure_mode = 1;
+
+	d->pc_happened = 1;
+	ubifs_warn("========== Power cut emulated ==========");
 	dump_stack();
 	return 1;
 }
 
-static void cut_data(const void *buf, int len)
+static void cut_data(const void *buf, unsigned int len)
 {
-	int flen, i;
+	unsigned int from, to, i, ffs = chance(1, 2);
 	unsigned char *p = (void *)buf;
 
-	flen = (len * (long long)simple_rand()) >> 15;
-	for (i = flen; i < len; i++)
-		p[i] = 0xff;
-}
+	from = random32() % (len + 1);
+	if (chance(1, 2))
+		to = random32() % (len - from + 1);
+	else
+		to = len;
 
-int dbg_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
-		 int len, int check)
-{
-	if (in_failure_mode(desc))
-		return -EROFS;
-	return ubi_leb_read(desc, lnum, buf, offset, len, check);
+	if (from < to)
+		ubifs_warn("filled bytes %u-%u with %s", from, to - 1,
+			   ffs ? "0xFFs" : "random data");
+
+	if (ffs)
+		for (i = from; i < to; i++)
+			p[i] = 0xFF;
+	else
+		for (i = from; i < to; i++)
+			p[i] = random32() % 0x100;
 }
 
-int dbg_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,