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

* 'linux-next' of git://git.infradead.org/ubifs-2.6:
  UBIFS: fix debugging dump
  UBIFS: improve lprops dump
  UBIFS: various minor commentary fixes
  UBIFS: improve journal head debugging prints
  UBIFS: define journal head numbers in ubifs-media.h
  UBIFS: amend commentaries
  UBIFS: check ubifs_scan error codes better
  UBIFS: do not print scary error messages needlessly
  UBIFS: add inode size debugging check
  UBIFS: constify file and inode operations
  UBIFS: remove unneeded call from ubifs_sync_fs
  UBIFS: kill BKL
  UBIFS: remove unused functions
  UBIFS: suppress compilation warning

22 files changed, 345 insertions, 181 deletions

diff --git a/fs/ubifs/budget.c b/fs/ubifs/budget.c
index ee1ce68fd98b..076ca50e9933 100644
--- a/fs/ubifs/budget.c
+++ b/fs/ubifs/budget.c
@@ -715,7 +715,7 @@ long long ubifs_get_free_space_nolock(struct ubifs_info *c)
  * ubifs_get_free_space - return amount of free space.
  * @c: UBIFS file-system description object
  *
- * This function calculates and retuns amount of free space to report to
+ * This function calculates and returns amount of free space to report to
  * user-space.
  */
 long long ubifs_get_free_space(struct ubifs_info *c)
diff --git a/fs/ubifs/commit.c b/fs/ubifs/commit.c
index f3a7945527fb..4775af401167 100644
--- a/fs/ubifs/commit.c
+++ b/fs/ubifs/commit.c
@@ -510,7 +510,7 @@ int dbg_check_old_index(struct ubifs_info *c, struct ubifs_zbranch *zroot)
 	int lnum, offs, len, err = 0, uninitialized_var(last_level), child_cnt;
 	int first = 1, iip;
 	struct ubifs_debug_info *d = c->dbg;
-	union ubifs_key lower_key, upper_key, l_key, u_key;
+	union ubifs_key uninitialized_var(lower_key), upper_key, l_key, u_key;
 	unsigned long long uninitialized_var(last_sqnum);
 	struct ubifs_idx_node *idx;
 	struct list_head list;
diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index ce2cd8343618..dbc093afd946 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -210,6 +210,20 @@ const char *dbg_cstate(int cmt_state)
 	}
 }
 
+const char *dbg_jhead(int jhead)
+{
+	switch (jhead) {
+	case GCHD:
+		return "0 (GC)";
+	case BASEHD:
+		return "1 (base)";
+	case DATAHD:
+		return "2 (data)";
+	default:
+		return "unknown journal head";
+	}
+}
+
 static void dump_ch(const struct ubifs_ch *ch)
 {
 	printk(KERN_DEBUG "\tmagic          %#x\n", le32_to_cpu(ch->magic));
@@ -623,8 +637,9 @@ void dbg_dump_budg(struct ubifs_info *c)
 	/* If we are in R/O mode, journal heads do not exist */
 	if (c->jheads)
 		for (i = 0; i < c->jhead_cnt; i++)
-			printk(KERN_DEBUG "\tjhead %d\t LEB %d\n",
-			       c->jheads[i].wbuf.jhead, c->jheads[i].wbuf.lnum);
+			printk(KERN_DEBUG "\tjhead %s\t LEB %d\n",
+			       dbg_jhead(c->jheads[i].wbuf.jhead),
+			       c->jheads[i].wbuf.lnum);
 	for (rb = rb_first(&c->buds); rb; rb = rb_next(rb)) {
 		bud = rb_entry(rb, struct ubifs_bud, rb);
 		printk(KERN_DEBUG "\tbud LEB %d\n", bud->lnum);
@@ -648,9 +663,90 @@ void dbg_dump_budg(struct ubifs_info *c)
 
 void dbg_dump_lprop(const struct ubifs_info *c, const struct ubifs_lprops *lp)
 {
-	printk(KERN_DEBUG "LEB %d lprops: free %d, dirty %d (used %d), "
-	       "flags %#x\n", lp->lnum, lp->free, lp->dirty,
-	       c->leb_size - lp->free - lp->dirty, lp->flags);
+	int i, spc, dark = 0, dead = 0;
+	struct rb_node *rb;
+	struct ubifs_bud *bud;
+
+	spc = lp->free + lp->dirty;
+	if (spc < c->dead_wm)
+		dead = spc;
+	else
+		dark = ubifs_calc_dark(c, spc);
+
+	if (lp->flags & LPROPS_INDEX)
+		printk(KERN_DEBUG "LEB %-7d free %-8d dirty %-8d used %-8d "
+		       "free + dirty %-8d flags %#x (", lp->lnum, lp->free,
+		       lp->dirty, c->leb_size - spc, spc, lp->flags);
+	else
+		printk(KERN_DEBUG "LEB %-7d free %-8d dirty %-8d used %-8d "
+		       "free + dirty %-8d dark %-4d dead %-4d nodes fit %-3d "
+		       "flags %#-4x (", lp->lnum, lp->free, lp->dirty,
+		       c->leb_size - spc, spc, dark, dead,
+		       (int)(spc / UBIFS_MAX_NODE_SZ), lp->flags);
+
+	if (lp->flags & LPROPS_TAKEN) {
+		if (lp->flags & LPROPS_INDEX)
+			printk(KERN_CONT "index, taken");
+		else
+			printk(KERN_CONT "taken");
+	} else {
+		const char *s;
+
+		if (lp->flags & LPROPS_INDEX) {
+			switch (lp->flags & LPROPS_CAT_MASK) {
+			case LPROPS_DIRTY_IDX:
+				s = "dirty index";
+				break;
+			case LPROPS_FRDI_IDX:
+				s = "freeable index";
+				break;
+			default:
+				s = "index";
+			}
+		} else {
+			switch (lp->flags & LPROPS_CAT_MASK) {
+			case LPROPS_UNCAT:
+				s = "not categorized";
+				break;
+			case LPROPS_DIRTY:
+				s = "dirty";
+				break;
+			case LPROPS_FREE:
+				s = "free";
+				break;
+			case LPROPS_EMPTY:
+				s = "empty";
+				break;
+			case LPROPS_FREEABLE:
+				s = "freeable";
+				break;
+			default:
+				s = NULL;
+				break;
+			}
+		}
+		printk(KERN_CONT "%s", s);
+	}
+
+	for (rb = rb_first((struct rb_root *)&c->buds); rb; rb = rb_next(rb)) {
+		bud = rb_entry(rb, struct ubifs_bud, rb);
+		if (bud->lnum == lp->lnum) {
+			int head = 0;
+			for (i = 0; i < c->jhead_cnt; i++) {
+				if (lp->lnum == c->jheads[i].wbuf.lnum) {
+					printk(KERN_CONT ", jhead %s",
+					       dbg_jhead(i));
+					head = 1;
+				}
+			}
+			if (!head)
+				printk(KERN_CONT ", bud of jhead %s",
+				       dbg_jhead(bud->jhead));
+		}
+	}
+	if (lp->lnum == c->gc_lnum)
+		printk(KERN_CONT ", GC LEB");
+	printk(KERN_CONT ")\n");
 }
 
 void dbg_dump_lprops(struct ubifs_info *c)
@@ -724,7 +820,7 @@ void dbg_dump_leb(const struct ubifs_info *c, int lnum)
 
 	printk(KERN_DEBUG "(pid %d) start dumping LEB %d\n",
 	       current->pid, lnum);
-	sleb = ubifs_scan(c, lnum, 0, c->dbg->buf);
+	sleb = ubifs_scan(c, lnum, 0, c->dbg->buf, 0);
 	if (IS_ERR(sleb)) {
 		ubifs_err("scan error %d", (int)PTR_ERR(sleb));
 		return;
@@ -909,8 +1005,10 @@ out:
 	ubifs_msg("saved lprops statistics dump");
 	dbg_dump_lstats(&d->saved_lst);
 	ubifs_get_lp_stats(c, &lst);
+
 	ubifs_msg("current lprops statistics dump");
-	dbg_dump_lstats(&d->saved_lst);
+	dbg_dump_lstats(&lst);
+
 	spin_lock(&c->space_lock);
 	dbg_dump_budg(c);
 	spin_unlock(&c->space_lock);
diff --git a/fs/ubifs/debug.h b/fs/ubifs/debug.h
index c1cd73b2e06e..29d960101ea6 100644
--- a/fs/ubifs/debug.h
+++ b/fs/ubifs/debug.h
@@ -271,6 +271,7 @@ void ubifs_debugging_exit(struct ubifs_info *c);
 /* Dump functions */
 const char *dbg_ntype(int type);
 const char *dbg_cstate(int cmt_state);
+const char *dbg_jhead(int jhead);
 const char *dbg_get_key_dump(const struct ubifs_info *c,
 			     const union ubifs_key *key);
 void dbg_dump_inode(const struct ubifs_info *c, const struct inode *inode);
@@ -321,6 +322,8 @@ void dbg_check_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap, int cat,
 int dbg_check_lprops(struct ubifs_info *c);
 int dbg_check_lpt_nodes(struct ubifs_info *c, struct ubifs_cnode *cnode,
 			int row, int col);
+int dbg_check_inode_size(struct ubifs_info *c, const struct inode *inode,
+			 loff_t size);
 
 /* Force the use of in-the-gaps method for testing */
 
@@ -425,6 +428,7 @@ void dbg_debugfs_exit_fs(struct ubifs_info *c);
 
 #define dbg_ntype(type)                        ""
 #define dbg_cstate(cmt_state)                  ""
+#define dbg_jhead(jhead)                       ""
 #define dbg_get_key_dump(c, key)               ({})
 #define dbg_dump_inode(c, inode)               ({})
 #define dbg_dump_node(c, node)                 ({})
@@ -460,6 +464,7 @@ void dbg_debugfs_exit_fs(struct ubifs_info *c);
 #define dbg_check_heap(c, heap, cat, add_pos)      ({})
 #define dbg_check_lprops(c)                        0
 #define dbg_check_lpt_nodes(c, cnode, row, col)    0
+#define dbg_check_inode_size(c, inode, size)       0
 #define dbg_force_in_the_gaps_enabled              0
 #define dbg_force_in_the_gaps()                    0
 #define dbg_failure_mode                           0
diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index 6d34dc7e33e1..2e6481a7701c 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -21,34 +21,32 @@
  */
 
 /*
- * This file implements VFS file and inode operations of regular files, device
+ * This file implements VFS file and inode operations for regular files, device
  * nodes and symlinks as well as address space operations.
  *
- * UBIFS uses 2 page flags: PG_private and PG_checked. PG_private is set if the
- * page is dirty and is used for budgeting purposes - dirty pages should not be
- * budgeted. The PG_checked flag is set if full budgeting is required for the
- * page e.g., when it corresponds to a file hole or it is just beyond the file
- * size. The budgeting is done in 'ubifs_write_begin()', because it is OK to
- * fail in this function, and the budget is released in 'ubifs_write_end()'. So
- * the PG_private and PG_checked flags carry the information about how the page
- * was budgeted, to make it possible to release the budget properly.
+ * UBIFS uses 2 page flags: @PG_private and @PG_checked. @PG_private is set if
+ * the page is dirty and is used for optimization purposes - dirty pages are
+ * not budgeted so the flag shows that 'ubifs_write_end()' should not release
+ * the budget for this page. The @PG_checked flag is set if full budgeting is
+ * required for the page e.g., when it corresponds to a file hole or it is
+ * beyond the file size. The budgeting is done in 'ubifs_write_begin()', because
+ * it is OK to fail in this function, and the budget is released in
+ * 'ubifs_write_end()'. So the @PG_private and @PG_checked flags carry
+ * information about how the page was budgeted, to make it possible to release
+ * the budget properly.
  *
- * A thing to keep in mind: inode's 'i_mutex' is locked in most VFS operations
- * we implement. However, this is not true for '->writepage()', which might be
- * called with 'i_mutex' unlocked. For example, when pdflush is performing
- * write-back, it calls 'writepage()' with unlocked 'i_mutex', although the
- * inode has 'I_LOCK' flag in this case. At "normal" work-paths 'i_mutex' is
- * locked in '->writepage', e.g. in "sys_write -> alloc_pages -> direct reclaim
- * path'. So, in '->writepage()' we are only guaranteed that the page is
- * locked.
+ * A thing to keep in mind: inode @i_mutex is locked in most VFS operations we
+ * implement. However, this is not true for 'ubifs_writepage()', which may be
+ * called with @i_mutex unlocked. For example, when pdflush is doing background
+ * write-back, it calls 'ubifs_writepage()' with unlocked @i_mutex. At "normal"
+ * work-paths the @i_mutex is locked in 'ubifs_writepage()', e.g. in the
+ * "sys_write -> alloc_pages -> direct reclaim path". So, in 'ubifs_writepage()'
+ * we are only guaranteed that the page is locked.
  *
- * Similarly, 'i_mutex' does not have to be locked in readpage(), e.g.,
- * readahead path does not have it locked ("sys_read -> generic_file_aio_read
- * -> ondemand_readahead -> readpage"). In case of readahead, 'I_LOCK' flag is
- * not set as well. However, UBIFS disables readahead.
- *
- * This, for example means that there might be 2 concurrent '->writepage()'
- * calls for the same inode, but different inode dirty pages.
+ * Similarly, @i_mutex is not always locked in 'ubifs_readpage()', e.g., the
+ * read-ahead path does not lock it ("sys_read -> generic_file_aio_read ->
+ * ondemand_readahead -> readpage"). In case of readahead, @I_LOCK flag is not
+ * set as well. However, UBIFS disables readahead.
  */
 
 #include "ubifs.h"
@@ -449,9 +447,9 @@ static int ubifs_write_begin(struct file *file, struct address_space *mapping,
 			/*
 			 * We change whole page so no need to load it. But we
 			 * have to set the @PG_checked flag to make the further
-			 * code the page is new. This might be not true, but it
-			 * is better to budget more that to read the page from
-			 * the media.
+			 * code know that the page is new. This might be not
+			 * true, but it is better to budget more than to read
+			 * the page from the media.
 			 */
 			SetPageChecked(page);
 			skipped_read = 1;
@@ -497,8 +495,8 @@ static int ubifs_write_begin(struct file *file, struct address_space *mapping,
 	}
 
 	/*
-	 * Whee, we aquired budgeting quickly - without involving
-	 * garbage-collection, committing or forceing write-back. We return
+	 * Whee, we acquired budgeting quickly - without involving
+	 * garbage-collection, committing or forcing write-back. We return
 	 * with @ui->ui_mutex locked if we are appending pages, and unlocked
 	 * otherwise. This is an optimization (slightly hacky though).
 	 */
@@ -562,7 +560,7 @@ static int ubifs_write_end(struct file *file, struct address_space *mapping,
 
 		/*
 		 * Return 0 to force VFS to repeat the whole operation, or the
-		 * error code if 'do_readpage()' failes.
+		 * error code if 'do_readpage()' fails.
 		 */
 		copied = do_readpage(page);
 		goto out;
@@ -1175,11 +1173,11 @@ static int do_truncation(struct ubifs_info *c, struct inode *inode,
 	ui->ui_size = inode->i_size;
 	/* Truncation changes inode [mc]time */
 	inode->i_mtime = inode->i_ctime = ubifs_current_time(inode);
-	/* The other attributes may be changed at the same time as well */
+	/* Other attributes may be changed at the same time as well */
 	do_attr_changes(inode, attr);
-
 	err = ubifs_jnl_truncate(c, inode, old_size, new_size);
 	mutex_unlock(&ui->ui_mutex);
+
 out_budg:
 	if (budgeted)
 		ubifs_release_budget(c, &req);
diff --git a/fs/ubifs/gc.c b/fs/ubifs/gc.c
index f0f5f15d384e..618c2701d3a7 100644
--- a/fs/ubifs/gc.c
+++ b/fs/ubifs/gc.c
@@ -529,7 +529,7 @@ int ubifs_garbage_collect_leb(struct ubifs_info *c, struct ubifs_lprops *lp)
 	 * We scan the entire LEB even though we only really need to scan up to
 	 * (c->leb_size - lp->free).
 	 */
-	sleb = ubifs_scan(c, lnum, 0, c->sbuf);
+	sleb = ubifs_scan(c, lnum, 0, c->sbuf, 0);
 	if (IS_ERR(sleb))
 		return PTR_ERR(sleb);
 
diff --git a/fs/ubifs/io.c b/fs/ubifs/io.c
index 762a7d6cec73..e589fedaf1ef 100644
--- a/fs/ubifs/io.c
+++ b/fs/ubifs/io.c
@@ -297,7 +297,7 @@ static enum hrtimer_restart wbuf_timer_callback_nolock(struct hrtimer *timer)
 {
 	struct ubifs_wbuf *wbuf = container_of(timer, struct ubifs_wbuf, timer);
 
-	dbg_io("jhead %d", wbuf->jhead);
+	dbg_io("jhead %s", dbg_jhead(wbuf->jhead));
 	wbuf->need_sync = 1;
 	wbuf->c->need_wbuf_sync = 1;
 	ubifs_wake_up_bgt(wbuf->c);
@@ -314,7 +314,8 @@ static void new_wbuf_timer_nolock(struct ubifs_wbuf *wbuf)
 
 	if (wbuf->no_timer)
 		return;
-	dbg_io("set timer for jhead %d, %llu-%llu millisecs", wbuf->jhead,
+	dbg_io("set timer for jhead %s, %llu-%llu millisecs",
+	       dbg_jhead(wbuf->jhead),
 	       div_u64(ktime_to_ns(wbuf->softlimit), USEC_PER_SEC),
 	       div_u64(ktime_to_ns(wbuf->softlimit) + wbuf->delta,
 		       USEC_PER_SEC));
@@ -351,8 +352,8 @@ int ubifs_wbuf_sync_nolock(struct ubifs_wbuf *wbuf)
 		/* Write-buffer is empty or not seeked */
 		return 0;
 
-	dbg_io("LEB %d:%d, %d bytes, jhead %d",
-	       wbuf->lnum, wbuf->offs, wbuf->used, wbuf->jhead);
+	dbg_io("LEB %d:%d, %d bytes, jhead %s",
+	       wbuf->lnum, wbuf->offs, wbuf->used, dbg_jhead(wbuf->jhead));
 	ubifs_assert(!(c->vfs_sb->s_flags & MS_RDONLY));
 	ubifs_assert(!(wbuf->avail & 7));
 	ubifs_assert(wbuf->offs + c->min_io_size <= c->leb_size);
@@ -401,7 +402,7 @@ int ubifs_wbuf_seek_nolock(struct ubifs_wbuf *wbuf, int lnum, int offs,
 {
 	const struct ubifs_info *c = wbuf->c;
 
-	dbg_io("LEB %d:%d, jhead %d", lnum, offs, wbuf->jhead);
+	dbg_io("LEB %d:%d, jhead %s", lnum, offs, dbg_jhead(wbuf->jhead));
 	ubifs_assert(lnum >= 0 && lnum < c->leb_cnt);
 	ubifs_assert(offs >= 0 && offs <= c->leb_size);
 	ubifs_assert(offs % c->min_io_size == 0 && !(offs & 7));
@@ -508,9 +509,9 @@ int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len)
 	struct ubifs_info *c = wbuf->c;
 	int err, written, n, aligned_len = ALIGN(len, 8), offs;
 
-	dbg_io("%d bytes (%s) to jhead %d wbuf at LEB %d:%d", len,
-	       dbg_ntype(((struct ubifs_ch *)buf)->node_type), wbuf->jhead,
-	       wbuf->lnum, wbuf->offs + wbuf->used);
+	dbg_io("%d bytes (%s) to jhead %s wbuf at LEB %d:%d", len,
+	       dbg_ntype(((struct ubifs_ch *)buf)->node_type),
+	       dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs + wbuf->used);
 	ubifs_assert(len > 0 && wbuf->lnum >= 0 && wbuf->lnum < c->leb_cnt);
 	ubifs_assert(wbuf->offs >= 0 && wbuf->offs % c->min_io_size == 0);
 	ubifs_assert(!(wbuf->offs & 7) && wbuf->offs <= c->leb_size);
@@ -535,8 +536,8 @@ int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len)
 		memcpy(wbuf->buf + wbuf->used, buf, len);
 
 		if (aligned_len == wbuf->avail) {
-			dbg_io("flush jhead %d wbuf to LEB %d:%d",
-			       wbuf->jhead, wbuf->lnum, wbuf->offs);
+			dbg_io("flush jhead %s wbuf to LEB %d:%d",
+			       dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs);
 			err = ubi_leb_write(c->ubi, wbuf->lnum, wbuf->buf,
 					    wbuf->offs, c->min_io_size,
 					    wbuf->dtype);
@@ -564,8 +565,8 @@ int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len)
 	 * minimal I/O unit. We have to fill and flush write-buffer and switch
 	 * to the next min. I/O unit.
 	 */
-	dbg_io("flush jhead %d wbuf to LEB %d:%d",
-	       wbuf->jhead, wbuf->lnum, wbuf->offs);
+	dbg_io("flush jhead %s wbuf to LEB %d:%d",
+	       dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs);
 	memcpy(wbuf->buf + wbuf->used, buf, wbuf->avail);
 	err = ubi_leb_write(c->ubi, wbuf->lnum, wbuf->buf, wbuf->offs,
 			    c->min_io_size, wbuf->dtype);
@@ -698,8 +699,8 @@ int ubifs_read_node_wbuf(struct ubifs_wbuf *wbuf, void *buf, int type, int len,
 	int err, rlen, overlap;
 	struct ubifs_ch *ch = buf;
 
-	dbg_io("LEB %d:%d, %s, length %d, jhead %d", lnum, offs,
-	       dbg_ntype(type), len, wbuf->jhead);
+	dbg_io("LEB %d:%d, %s, length %d, jhead %s", lnum, offs,
+	       dbg_ntype(type), len, dbg_jhead(wbuf->jhead));
 	ubifs_assert(wbuf && lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
 	ubifs_assert(!(offs & 7) && offs < c->leb_size);
 	ubifs_assert(type >= 0 && type < UBIFS_NODE_TYPES_CNT);
diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c
index 64b5f3a309f5..d321baeca68d 100644
--- a/fs/ubifs/journal.c
+++ b/fs/ubifs/journal.c
@@ -158,7 +158,7 @@ again:
 	 * some. But the write-buffer mutex has to be unlocked because
 	 * GC also takes it.
 	 */
-	dbg_jnl("no free space  jhead %d, run GC", jhead);
+	dbg_jnl("no free space in jhead %s, run GC", dbg_jhead(jhead));
 	mutex_unlock(&wbuf->io_mutex);
 
 	lnum = ubifs_garbage_collect(c, 0);
@@ -173,7 +173,8 @@ again:
 		 * because we dropped @wbuf->io_mutex, so try once
 		 * again.
 		 */
-		dbg_jnl("GC couldn't make a free LEB for jhead %d", jhead);
+		dbg_jnl("GC couldn't make a free LEB for jhead %s",
+			dbg_jhead(jhead));
 		if (retries++ < 2) {
 			dbg_jnl("retry (%d)", retries);
 			goto again;
@@ -184,7 +185,7 @@ again:
 	}
 
 	mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
-	dbg_jnl("got LEB %d for jhead %d", lnum, jhead);
+	dbg_jnl("got LEB %d for jhead %s", lnum, dbg_jhead(jhead));
 	avail = c->leb_size - wbuf->offs - wbuf->used;
 
 	if (wbuf->lnum != -1 && avail >= len) {
@@ -255,7 +256,8 @@ static int write_node(struct ubifs_info *c, int jhead, void *node, int len,
 	*lnum = c->jheads[jhead].wbuf.lnum;
 	*offs = c->jheads[jhead].wbuf.offs + c->jheads[jhead].wbuf.used;
 
-	dbg_jnl("jhead %d, LEB %d:%d, len %d", jhead, *lnum, *offs, len);
+	dbg_jnl("jhead %s, LEB %d:%d, len %d",
+		dbg_jhead(jhead), *lnum, *offs, len);
 	ubifs_prepare_node(c, node, len, 0);
 
 	return ubifs_wbuf_write_nolock(wbuf, node, len);
@@ -285,7 +287,8 @@ static int write_head(struct ubifs_info *c, int jhead, void *buf, int len,
 
 	*lnum = c->jheads[jhead].wbuf.lnum;
 	*offs = c->jheads[jhead].wbuf.offs + c->jheads[jhead].wbuf.used;
-	dbg_jnl("jhead %d, LEB %d:%d, len %d", jhead, *lnum, *offs, len);
+	dbg_jnl("jhead %s, LEB %d:%d, len %d",
+		dbg_jhead(jhead), *lnum, *offs, len);
 
 	err = ubifs_wbuf_write_nolock(wbuf, buf, len);
 	if (err)
diff --git a/fs/ubifs/key.h b/fs/ubifs/key.h
index 5fa27ea031ba..0f530c684f0b 100644
--- a/fs/ubifs/key.h
+++ b/fs/ubifs/key.h
@@ -229,23 +229,6 @@ static inline void xent_key_init(const struct ubifs_info *c,
 }
 
 /**
- * xent_key_init_hash - initialize extended attribute entry key without
- *                      re-calculating hash function.
- * @c: UBIFS file-system description object
- * @key: key to initialize
- * @inum: host inode number
- * @hash: extended attribute entry name hash
- */
-static inline void xent_key_init_hash(const struct ubifs_info *c,
-				      union ubifs_key *key, ino_t inum,
-				      uint32_t hash)
-{
-	ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
-	key->u32[0] = inum;
-	key->u32[1] = hash | (UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS);
-}
-
-/**
  * xent_key_init_flash - initialize on-flash extended attribute entry key.
  * @c: UBIFS file-system description object
  * @k: key to initialize
@@ -295,22 +278,15 @@ static inline void data_key_init(const struct ubifs_info *c,
 }
 
 /**
- * data_key_init_flash - initialize on-flash data key.
+ * highest_data_key - get the highest possible data key for an inode.
  * @c: UBIFS file-system description object
- * @k: key to initialize
+ * @key: key to initialize
  * @inum: inode number
- * @block: block number
  */
-static inline void data_key_init_flash(const struct ubifs_info *c, void *k,
-				       ino_t inum, unsigned int block)
+static inline void highest_data_key(const struct ubifs_info *c,
+				   union ubifs_key *key, ino_t inum)
 {
-	union ubifs_key *key = k;
-
-	ubifs_assert(!(block & ~UBIFS_S_KEY_BLOCK_MASK));
-	key->j32[0] = cpu_to_le32(inum);
-	key->j32[1] = cpu_to_le32(block |
-				  (UBIFS_DATA_KEY << UBIFS_S_KEY_BLOCK_BITS));
-	memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
+	data_key_init(c, key, inum, UBIFS_S_KEY_BLOCK_MASK);
 }
 
 /**
@@ -554,4 +530,5 @@ static inline unsigned long long key_max_inode_size(const struct ubifs_info *c)
 		return 0;
 	}
 }
+
 #endif /* !__UBIFS_KEY_H__ */
diff --git a/fs/ubifs/log.c b/fs/ubifs/log.c
index 56e33772a1ee..c345e125f42c 100644
--- a/fs/ubifs/log.c
+++ b/fs/ubifs/log.c
@@ -169,8 +169,8 @@ void ubifs_add_bud(struct ubifs_info *c, struct ubifs_bud *bud)
 	 */
 	c->bud_bytes += c->leb_size - bud->start;
 
-	dbg_log("LEB %d:%d, jhead %d, bud_bytes %lld", bud->lnum,
-		bud->start, bud->jhead, c->bud_bytes);
+	dbg_log("LEB %d:%d, jhead %s, bud_bytes %lld", bud->lnum,
+		bud->start, dbg_jhead(bud->jhead), c->bud_bytes);
 	spin_unlock(&c->buds_lock);
 }
 
@@ -355,16 +355,16 @@ static void remove_buds(struct ubifs_info *c)
 			 * heads (non-closed buds).
 			 */
 			c->cmt_bud_bytes += wbuf->offs - bud->start;
-			dbg_log("preserve %d:%d, jhead %d, bud bytes %d, "
+			dbg_log("preserve %d:%d, jhead %s, bud bytes %d, "
 				"cmt_bud_bytes %lld", bud->lnum, bud->start,
-				bud->jhead, wbuf->offs - bud->start,
+				dbg_jhead(bud->jhead), wbuf->offs - bud->start,
 				c->cmt_bud_bytes);
 			bud->start = wbuf->offs;
 		} else {
 			c->cmt_bud_bytes += c->leb_size - bud->start;
-			dbg_log("remove %d:%d, jhead %d, bud bytes %d, "
+			dbg_log("remove %d:%d, jhead %s, bud bytes %d, "
 				"cmt_bud_bytes %lld", bud->lnum, bud->start,
-				bud->jhead, c->leb_size - bud->start,
+				dbg_jhead(bud->jhead), c->leb_size - bud->start,
 				c->cmt_bud_bytes);
 			rb_erase(p1, &c->buds);
 			/*
@@ -429,7 +429,8 @@ int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum)
 		if (lnum == -1 || offs == c->leb_size)
 			continue;
 
-		dbg_log("add ref to LEB %d:%d for jhead %d", lnum, offs, i);
+		dbg_log("add ref to LEB %d:%d for jhead %s",
+			lnum, offs, dbg_jhead(i));
 		ref = buf + len;
 		ref->ch.node_type = UBIFS_REF_NODE;
 		ref->lnum = cpu_to_le32(lnum);
@@ -695,7 +696,7 @@ int ubifs_consolidate_log(struct ubifs_info *c)
 	lnum = c->ltail_lnum;
 	write_lnum = lnum;
 	while (1) {
-		sleb = ubifs_scan(c, lnum, 0, c->sbuf);
+		sleb = ubifs_scan(c, lnum, 0, c->sbuf, 0);
 		if (IS_ERR(sleb)) {
 			err = PTR_ERR(sleb);
 			goto out_free;
diff --git a/fs/ubifs/lprops.c b/fs/ubifs/lprops.c
index 4cdd284dea56..4d4ca388889b 100644
--- a/fs/ubifs/lprops.c
+++ b/fs/ubifs/lprops.c
@@ -281,7 +281,7 @@ void ubifs_add_to_cat(struct ubifs_info *c, struct ubifs_lprops *lprops,
 	case LPROPS_FREE:
 		if (add_to_lpt_heap(c, lprops, cat))
 			break;
-		/* No more room on heap so make it uncategorized */
+		/* No more room on heap so make it un-categorized */
 		cat = LPROPS_UNCAT;
 		/* Fall through */
 	case LPROPS_UNCAT:
@@ -375,8 +375,8 @@ void ubifs_replace_cat(struct ubifs_info *c, struct ubifs_lprops *old_lprops,
  * @lprops: LEB properties
  *
  * A LEB may have fallen off of the bottom of a heap, and ended up as
- * uncategorized even though it has enough space for us now. If that is the case
- * this function will put the LEB back onto a heap.
+ * un-categorized even though it has enough space for us now. If that is the
+ * case this function will put the LEB back onto a heap.
  */
 void ubifs_ensure_cat(struct ubifs_info *c, struct ubifs_lprops *lprops)
 {
@@ -436,10 +436,10 @@ int ubifs_categorize_lprops(const struct ubifs_info *c,
 /**
  * change_category - change LEB properties category.
  * @c: UBIFS file-system description object
- * @lprops: LEB properties to recategorize
+ * @lprops: LEB properties to re-categorize
  *
  * LEB properties are categorized to enable fast find operations. When the LEB
- * properties change they must be recategorized.
+ * properties change they must be re-categorized.
  */
 static void change_category(struct ubifs_info *c, struct ubifs_lprops *lprops)
 {
@@ -461,21 +461,18 @@ static void change_category(struct ubifs_info *c, struct ubifs_lprops *lprops)
 }
 
 /**
- * calc_dark - calculate LEB dark space size.
+ * ubifs_calc_dark - calculate LEB dark space size.
  * @c: the UBIFS file-system description object
  * @spc: amount of free and dirty space in the LEB
  *
- * This function calculates amount of dark space in an LEB which has @spc bytes
- * of free and dirty space. Returns the calculations result.
+ * This function calculates and returns amount of dark space in an LEB which
+ * has @spc bytes of free and dirty space.
  *
- * Dark space is the space which is not always usable - it depends on which
- * nodes are written in which order. E.g., if an LEB has only 512 free bytes,
- * it is dark space, because it cannot fit a large data node. So UBIFS cannot
- * count on this LEB and treat these 512 bytes as usable because it is not true
- * if, for example, only big chunks of uncompressible data will be written to
- * the FS.
+ * UBIFS is trying to account the space which might not be usable, and this
+ * space is called "dark space". For example, if an LEB has only %512 free
+ * bytes, it is dark space, because it cannot fit a large data node.
  */
-static int calc_dark(struct ubifs_info *c, int spc)
+int ubifs_calc_dark(const struct ubifs_info *c, int spc)
 {
 	ubifs_assert(!(spc & 7));
 
@@ -518,7 +515,7 @@ static int is_lprops_dirty(struct ubifs_info *c, struct ubifs_lprops *lprops)
  * @free: new free space amount
  * @dirty: new dirty space amount
  * @flags: new flags
- * @idx_gc_cnt: change to the count of idx_gc list
+ * @idx_gc_cnt: change to the count of @idx_gc list
  *
  * This function changes LEB properties (@free, @dirty or @flag). However, the
  * property which has the %LPROPS_NC value is not changed. Returns a pointer to
@@ -535,7 +532,7 @@ const struct ubifs_lprops *ubifs_change_lp(struct ubifs_info *c,
 {
 	/*
 	 * This is the only function that is allowed to change lprops, so we
-	 * discard the const qualifier.
+	 * discard the "const" qualifier.
 	 */
 	struct ubifs_lprops *lprops = (struct ubifs_lprops *)lp;
 
@@ -575,7 +572,7 @@ const struct ubifs_lprops *ubifs_change_lp(struct ubifs_info *c,
 		if (old_spc < c->dead_wm)
 			c->lst.total_dead -= old_spc;
 		else
-			c->lst.total_dark -= calc_dark(c, old_spc);
+			c->lst.total_dark -= ubifs_calc_dark(c, old_spc);
 
 		c->lst.total_used -= c->leb_size - old_spc;
 	}
@@ -616,7 +613,7 @@ const struct ubifs_lprops *ubifs_change_lp(struct ubifs_info *c,
 		if (new_spc < c->dead_wm)
 			c->lst.total_dead += new_spc;
 		else
-			c->lst.total_dark += calc_dark(c, new_spc);
+			c->lst.total_dark += ubifs_calc_dark(c, new_spc);
 
 		c->lst.total_used += c->leb_size - new_spc;
 	}
@@ -1096,7 +1093,7 @@ static int scan_check_cb(struct ubifs_info *c,
 		}
 	}
 
-	sleb = ubifs_scan(c, lnum, 0, c->dbg->buf);
+	sleb = ubifs_scan(c, lnum, 0, c->dbg->buf, 0);
 	if (IS_ERR(sleb)) {
 		/*
 		 * After an unclean unmount, empty and freeable LEBs
@@ -1107,7 +1104,7 @@ static int scan_check_cb(struct ubifs_info *c,
 				  "- continuing checking");
 			lst->empty_lebs += 1;
 			lst->total_free += c->leb_size;
-			lst->total_dark += calc_dark(c, c->leb_size);
+			lst->total_dark += ubifs_calc_dark(c, c->leb_size);
 			return LPT_SCAN_CONTINUE;
 		}
 
@@ -1117,7 +1114,7 @@ static int scan_check_cb(struct ubifs_info *c,
 				  "- continuing checking");
 			lst->total_free  += lp->free;
 			lst->total_dirty += lp->dirty;
-			lst->total_dark  +=  calc_dark(c, c->leb_size);
+			lst->total_dark  +=  ubifs_calc_dark(c, c->leb_size);
 			return LPT_SCAN_CONTINUE;
 		}
 		data->err = PTR_ERR(sleb);
@@ -1235,7 +1232,7 @@ static int scan_check_cb(struct ubifs_info *c,
 		if (spc < c->dead_wm)
 			lst->total_dead += spc;
 		else
-			lst->total_dark += calc_dark(c, spc);
+			lst->total_dark += ubifs_calc_dark(c, spc);
 	}
 
 	ubifs_scan_destroy(sleb);
diff --git a/fs/ubifs/master.c b/fs/ubifs/master.c
index a88f33801b98..28beaeedadc0 100644
--- a/fs/ubifs/master.c
+++ b/fs/ubifs/master.c
@@ -29,7 +29,8 @@
  * @c: UBIFS file-system description object
  *
  * This function scans the master node LEBs and search for the latest master
- * node. Returns zero in case of success and a negative error code in case of
+ * node. Returns zero in case of success, %-EUCLEAN if there master area is
+ * corrupted and requires recovery, and a negative error code in case of
  * failure.
  */
 static int scan_for_master(struct ubifs_info *c)
@@ -40,7 +41,7 @@ static int scan_for_master(struct ubifs_info *c)
 
 	lnum = UBIFS_MST_LNUM;
 
-	sleb = ubifs_scan(c, lnum, 0, c->sbuf);
+	sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1);
 	if (IS_ERR(sleb))
 		return PTR_ERR(sleb);
 	nodes_cnt = sleb->nodes_cnt;
@@ -48,7 +49,7 @@ static int scan_for_master(struct ubifs_info *c)
 		snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node,
 				  list);
 		if (snod->type != UBIFS_MST_NODE)
-			goto out;
+			goto out_dump;
 		memcpy(c->mst_node, snod->node, snod->len);
 		offs = snod->offs;
 	}
@@ -56,7 +57,7 @@ static int scan_for_master(struct ubifs_info *c)
 
 	lnum += 1;
 
-	sleb = ubifs_scan(c, lnum, 0, c->sbuf);
+	sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1);
 	if (IS_ERR(sleb))
 		return PTR_ERR(sleb);
 	if (sleb->nodes_cnt != nodes_cnt)
@@ -65,7 +66,7 @@ static int scan_for_master(struct ubifs_info *c)
 		goto out;
 	snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, list);
 	if (snod->type != UBIFS_MST_NODE)
-		goto out;
+		goto out_dump;
 	if (snod->offs != offs)
 		goto out;
 	if (memcmp((void *)c->mst_node + UBIFS_CH_SZ,
@@ -78,6 +79,12 @@ static int scan_for_master(struct ubifs_info *c)
 
 out:
 	ubifs_scan_destroy(sleb);
+	return -EUCLEAN;
+
+out_dump:
+	ubifs_err("unexpected node type %d master LEB %d:%d",
+		  snod->type, lnum, snod->offs);<