1 files changed, 64 insertions, 33 deletions

diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index 0bee4dbffc3..004d3745dc4 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -43,8 +43,8 @@ DEFINE_SPINLOCK(dbg_lock);
 static char dbg_key_buf0[128];
 static char dbg_key_buf1[128];
 
-unsigned int ubifs_msg_flags = UBIFS_MSG_FLAGS_DEFAULT;
-unsigned int ubifs_chk_flags = UBIFS_CHK_FLAGS_DEFAULT;
+unsigned int ubifs_msg_flags;
+unsigned int ubifs_chk_flags;
 unsigned int ubifs_tst_flags;
 
 module_param_named(debug_msgs, ubifs_msg_flags, uint, S_IRUGO | S_IWUSR);
@@ -810,16 +810,24 @@ void dbg_dump_leb(const struct ubifs_info *c, int lnum)
 {
 	struct ubifs_scan_leb *sleb;
 	struct ubifs_scan_node *snod;
+	void *buf;
 
 	if (dbg_failure_mode)
 		return;
 
 	printk(KERN_DEBUG "(pid %d) start dumping LEB %d\n",
 	       current->pid, lnum);
-	sleb = ubifs_scan(c, lnum, 0, c->dbg->buf, 0);
+
+	buf = __vmalloc(c->leb_size, GFP_NOFS, PAGE_KERNEL);
+	if (!buf) {
+		ubifs_err("cannot allocate memory for dumping LEB %d", lnum);
+		return;
+	}
+
+	sleb = ubifs_scan(c, lnum, 0, buf, 0);
 	if (IS_ERR(sleb)) {
 		ubifs_err("scan error %d", (int)PTR_ERR(sleb));
-		return;
+		goto out;
 	}
 
 	printk(KERN_DEBUG "LEB %d has %d nodes ending at %d\n", lnum,
@@ -835,6 +843,9 @@ void dbg_dump_leb(const struct ubifs_info *c, int lnum)
 	printk(KERN_DEBUG "(pid %d) finish dumping LEB %d\n",
 	       current->pid, lnum);
 	ubifs_scan_destroy(sleb);
+
+out:
+	vfree(buf);
 	return;
 }
 
@@ -961,11 +972,39 @@ void dbg_dump_index(struct ubifs_info *c)
 void dbg_save_space_info(struct ubifs_info *c)
 {
 	struct ubifs_debug_info *d = c->dbg;
-
-	ubifs_get_lp_stats(c, &d->saved_lst);
+	int freeable_cnt;
 
 	spin_lock(&c->space_lock);
+	memcpy(&d->saved_lst, &c->lst, sizeof(struct ubifs_lp_stats));
+
+	/*
+	 * We use a dirty hack here and zero out @c->freeable_cnt, because it
+	 * affects the free space calculations, and UBIFS might not know about
+	 * all freeable eraseblocks. Indeed, we know about freeable eraseblocks
+	 * only when we read their lprops, and we do this only lazily, upon the
+	 * need. So at any given point of time @c->freeable_cnt might be not
+	 * exactly accurate.
+	 *
+	 * Just one example about the issue we hit when we did not zero
+	 * @c->freeable_cnt.
+	 * 1. The file-system is mounted R/O, c->freeable_cnt is %0. We save the
+	 *    amount of free space in @d->saved_free
+	 * 2. We re-mount R/W, which makes UBIFS to read the "lsave"
+	 *    information from flash, where we cache LEBs from various
+	 *    categories ('ubifs_remount_fs()' -> 'ubifs_lpt_init()'
+	 *    -> 'lpt_init_wr()' -> 'read_lsave()' -> 'ubifs_lpt_lookup()'
+	 *    -> 'ubifs_get_pnode()' -> 'update_cats()'
+	 *    -> 'ubifs_add_to_cat()').
+	 * 3. Lsave contains a freeable eraseblock, and @c->freeable_cnt
+	 *    becomes %1.
+	 * 4. We calculate the amount of free space when the re-mount is
+	 *    finished in 'dbg_check_space_info()' and it does not match
+	 *    @d->saved_free.
+	 */
+	freeable_cnt = c->freeable_cnt;
+	c->freeable_cnt = 0;
 	d->saved_free = ubifs_get_free_space_nolock(c);
+	c->freeable_cnt = freeable_cnt;
 	spin_unlock(&c->space_lock);
 }
 
@@ -982,12 +1021,15 @@ int dbg_check_space_info(struct ubifs_info *c)
 {
 	struct ubifs_debug_info *d = c->dbg;
 	struct ubifs_lp_stats lst;
-	long long avail, free;
+	long long free;
+	int freeable_cnt;
 
 	spin_lock(&c->space_lock);
-	avail = ubifs_calc_available(c, c->min_idx_lebs);
+	freeable_cnt = c->freeable_cnt;
+	c->freeable_cnt = 0;
+	free = ubifs_get_free_space_nolock(c);
+	c->freeable_cnt = freeable_cnt;
 	spin_unlock(&c->space_lock);
-	free = ubifs_get_free_space(c);
 
 	if (free != d->saved_free) {
 		ubifs_err("free space changed from %lld to %lld",
@@ -2690,16 +2732,8 @@ int ubifs_debugging_init(struct ubifs_info *c)
 	if (!c->dbg)
 		return -ENOMEM;
 
-	c->dbg->buf = vmalloc(c->leb_size);
-	if (!c->dbg->buf)
-		goto out;
-
 	failure_mode_init(c);
 	return 0;
-
-out:
-	kfree(c->dbg);
-	return -ENOMEM;
 }
 
 /**
@@ -2709,7 +2743,6 @@ out:
 void ubifs_debugging_exit(struct ubifs_info *c)
 {
 	failure_mode_exit(c);
-	vfree(c->dbg->buf);
 	kfree(c->dbg);
 }
 
@@ -2804,40 +2837,38 @@ int dbg_debugfs_init_fs(struct ubifs_info *c)
 	struct ubifs_debug_info *d = c->dbg;
 
 	sprintf(d->dfs_dir_name, "ubi%d_%d", c->vi.ubi_num, c->vi.vol_id);
-	d->dfs_dir = debugfs_create_dir(d->dfs_dir_name, dfs_rootdir);
-	if (IS_ERR(d->dfs_dir)) {
-		err = PTR_ERR(d->dfs_dir);
-		ubifs_err("cannot create \"%s\" debugfs directory, error %d\n",
-			  d->dfs_dir_name, err);
+	fname = d->dfs_dir_name;
+	dent = debugfs_create_dir(fname, dfs_rootdir);
+	if (IS_ERR_OR_NULL(dent))
 		goto out;
-	}
+	d->dfs_dir = dent;
 
 	fname = "dump_lprops";
-	dent = debugfs_create_file(fname, S_IWUGO, d->dfs_dir, c, &dfs_fops);
-	if (IS_ERR(dent))
+	dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, c, &dfs_fops);
+	if (IS_ERR_OR_NULL(dent))
 		goto out_remove;
 	d->dfs_dump_lprops = dent;
 
 	fname = "dump_budg";
-	dent = debugfs_create_file(fname, S_IWUGO, d->dfs_dir, c, &dfs_fops);
-	if (IS_ERR(dent))
+	dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, c, &dfs_fops);
+	if (IS_ERR_OR_NULL(dent))
 		goto out_remove;
 	d->dfs_dump_budg = dent;
 
 	fname = "dump_tnc";
-	dent = debugfs_create_file(fname, S_IWUGO, d->dfs_dir, c, &dfs_fops);
-	if (IS_ERR(dent))
+	dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, c, &dfs_fops);
+	if (IS_ERR_OR_NULL(dent))
 		goto out_remove;
 	d->dfs_dump_tnc = dent;
 
 	return 0;
 
 out_remove:
-	err = PTR_ERR(dent);
-	ubifs_err("cannot create \"%s\" debugfs directory, error %d\n",
-		  fname, err);
 	debugfs_remove_recursive(d->dfs_dir);
 out:
+	err = dent ? PTR_ERR(dent) : -ENODEV;
+	ubifs_err("cannot create \"%s\" debugfs directory, error %d\n",
+		  fname, err);
 	return err;
 }