Merge tag 'for-linus-5.17-rc1' of git://git.kernel.org/pub/scm/linux/…

…kernel/git/rw/ubifs

Pull JFFS2, UBI and UBIFS updates from Richard Weinberger:
 "JFFS2:
   - Fix for a deadlock in jffs2_write_begin()

  UBI:
   - Fixes in comments

  UBIFS:
   - Expose error counters in sysfs
   - Many bugfixes found by Hulk Robot and others"

* tag 'for-linus-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs:
  jffs2: GC deadlock reading a page that is used in jffs2_write_begin()
  ubifs: read-only if LEB may always be taken in ubifs_garbage_collect
  ubifs: fix double return leb in ubifs_garbage_collect
  ubifs: fix slab-out-of-bounds in ubifs_change_lp
  ubifs: fix snprintf() length check
  ubifs: Document sysfs nodes
  ubifs: Export filesystem error counters
  ubifs: Error path in ubifs_remount_rw() seems to wrongly free write buffers
  ubifs: Make use of the helper macro kthread_run()
  ubi: Fix a mistake in comment
  ubifs: Fix spelling mistakes

Documentation/ABI/testing/sysfs-fs-ubifs

@@ -0,0 +1,35 @@
+What:		/sys/fs/ubifsX_Y/error_magic
+Date:		October 2021
+KernelVersion:	5.16
+Contact:	[email protected]
+Description:
+		Exposes magic errors: every node starts with a magic number.
+
+		This counter keeps track of the number of accesses of nodes
+		with a corrupted magic number.
+
+		The counter is reset to 0 with a remount.
+
+What:		/sys/fs/ubifsX_Y/error_node
+Date:		October 2021
+KernelVersion:	5.16
+Contact:	[email protected]
+Description:
+		Exposes node errors. Every node embeds its type.
+
+		This counter keeps track of the number of accesses of nodes
+		with a corrupted node type.
+
+		The counter is reset to 0 with a remount.
+
+What:		/sys/fs/ubifsX_Y/error_crc
+Date:		October 2021
+KernelVersion:	5.16
+Contact:	[email protected]
+Description:
+		Exposes crc errors: every node embeds a crc checksum.
+
+		This counter keeps track of the number of accesses of nodes
+		with a bad crc checksum.
+
+		The counter is reset to 0 with a remount.

MAINTAINERS

@@ -19603,6 +19603,7 @@ S:	Supported
 W:	http://www.linux-mtd.infradead.org/doc/ubifs.html
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs.git next
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs.git fixes
+F:	Documentation/ABI/testing/sysfs-fs-ubifs
 F:	Documentation/filesystems/ubifs-authentication.rst
 F:	Documentation/filesystems/ubifs.rst
 F:	fs/ubifs/

drivers/mtd/ubi/debug.c

@@ -562,7 +562,7 @@ int ubi_debugfs_init_dev(struct ubi_device *ubi)
 }
 
 /**
- * dbg_debug_exit_dev - free all debugfs files corresponding to device @ubi
+ * ubi_debugfs_exit_dev - free all debugfs files corresponding to device @ubi
  * @ubi: UBI device description object
  */
 void ubi_debugfs_exit_dev(struct ubi_device *ubi)

fs/jffs2/file.c

@@ -136,20 +136,15 @@ static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
 	struct page *pg;
 	struct inode *inode = mapping->host;
 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
+	struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
 	pgoff_t index = pos >> PAGE_SHIFT;
 	uint32_t pageofs = index << PAGE_SHIFT;
 	int ret = 0;
 
-	pg = grab_cache_page_write_begin(mapping, index, flags);
-	if (!pg)
-		return -ENOMEM;
-	*pagep = pg;
-
 	jffs2_dbg(1, "%s()\n", __func__);
 
 	if (pageofs > inode->i_size) {
 		/* Make new hole frag from old EOF to new page */
-		struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
 		struct jffs2_raw_inode ri;
 		struct jffs2_full_dnode *fn;
 		uint32_t alloc_len;
@@ -160,7 +155,7 @@ static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
 		ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len,
 					  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
 		if (ret)
-			goto out_page;
+			goto out_err;
 
 		mutex_lock(&f->sem);
 		memset(&ri, 0, sizeof(ri));
@@ -190,7 +185,7 @@ static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
 			ret = PTR_ERR(fn);
 			jffs2_complete_reservation(c);
 			mutex_unlock(&f->sem);
-			goto out_page;
+			goto out_err;
 		}
 		ret = jffs2_add_full_dnode_to_inode(c, f, fn);
 		if (f->metadata) {
@@ -205,13 +200,26 @@ static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
 			jffs2_free_full_dnode(fn);
 			jffs2_complete_reservation(c);
 			mutex_unlock(&f->sem);
-			goto out_page;
+			goto out_err;
 		}
 		jffs2_complete_reservation(c);
 		inode->i_size = pageofs;
 		mutex_unlock(&f->sem);
 	}
 
+	/*
+	 * While getting a page and reading data in, lock c->alloc_sem until
+	 * the page is Uptodate. Otherwise GC task may attempt to read the same
+	 * page in read_cache_page(), which causes a deadlock.
+	 */
+	mutex_lock(&c->alloc_sem);
+	pg = grab_cache_page_write_begin(mapping, index, flags);
+	if (!pg) {
+		ret = -ENOMEM;
+		goto release_sem;
+	}
+	*pagep = pg;
+
 	/*
 	 * Read in the page if it wasn't already present. Cannot optimize away
 	 * the whole page write case until jffs2_write_end can handle the
@@ -221,15 +229,17 @@ static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
 		mutex_lock(&f->sem);
 		ret = jffs2_do_readpage_nolock(inode, pg);
 		mutex_unlock(&f->sem);
-		if (ret)
-			goto out_page;
+		if (ret) {
+			unlock_page(pg);
+			put_page(pg);
+			goto release_sem;
+		}
 	}
 	jffs2_dbg(1, "end write_begin(). pg->flags %lx\n", pg->flags);
-	return ret;
 
-out_page:
-	unlock_page(pg);
-	put_page(pg);
+release_sem:
+	mutex_unlock(&c->alloc_sem);
+out_err:
 	return ret;
 }
 

fs/ubifs/Makefile

@@ -5,7 +5,7 @@ ubifs-y += shrinker.o journal.o file.o dir.o super.o sb.o io.o
 ubifs-y += tnc.o master.o scan.o replay.o log.o commit.o gc.o orphan.o
 ubifs-y += budget.o find.o tnc_commit.o compress.o lpt.o lprops.o
 ubifs-y += recovery.o ioctl.o lpt_commit.o tnc_misc.o debug.o
-ubifs-y += misc.o
+ubifs-y += misc.o sysfs.o
 ubifs-$(CONFIG_FS_ENCRYPTION) += crypto.o
 ubifs-$(CONFIG_UBIFS_FS_XATTR) += xattr.o
 ubifs-$(CONFIG_UBIFS_FS_AUTHENTICATION) += auth.o

fs/ubifs/dir.c

@@ -1207,7 +1207,7 @@ static int ubifs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
  * @inode1: first inode
  * @inode2: second inode
  * @inode3: third inode
- * @inode4: fouth inode
+ * @inode4: fourth inode
  *
  * This function is used for 'ubifs_rename()' and @inode1 may be the same as
  * @inode2 whereas @inode3 and @inode4 may be %NULL.
@@ -1233,7 +1233,7 @@ static void lock_4_inodes(struct inode *inode1, struct inode *inode2,
  * @inode1: first inode
  * @inode2: second inode
  * @inode3: third inode
- * @inode4: fouth inode
+ * @inode4: fourth inode
  */
 static void unlock_4_inodes(struct inode *inode1, struct inode *inode2,
 			    struct inode *inode3, struct inode *inode4)

fs/ubifs/gc.c

@@ -692,6 +692,9 @@ int ubifs_garbage_collect(struct ubifs_info *c, int anyway)
 	for (i = 0; ; i++) {
 		int space_before, space_after;
 
+		/* Maybe continue after find and break before find */
+		lp.lnum = -1;
+
 		cond_resched();
 
 		/* Give the commit an opportunity to run */
@@ -753,8 +756,19 @@ int ubifs_garbage_collect(struct ubifs_info *c, int anyway)
 				 * caller instead of the original '-EAGAIN'.
 				 */
 				err = ubifs_return_leb(c, lp.lnum);
-				if (err)
+				if (err) {
 					ret = err;
+					/*
+					 * An LEB may always be "taken",
+					 * so setting ubifs to read-only,
+					 * and then executing sync wbuf will
+					 * return -EROFS and enter the "out"
+					 * error branch.
+					 */
+					ubifs_ro_mode(c, ret);
+				}
+				/*  Maybe double return LEB if goto out */
+				lp.lnum = -1;
 				break;
 			}
 			goto out;
@@ -843,7 +857,8 @@ int ubifs_garbage_collect(struct ubifs_info *c, int anyway)
 	ubifs_wbuf_sync_nolock(wbuf);
 	ubifs_ro_mode(c, ret);
 	mutex_unlock(&wbuf->io_mutex);
-	ubifs_return_leb(c, lp.lnum);
+	if (lp.lnum != -1)
+		ubifs_return_leb(c, lp.lnum);
 	return ret;
 }
 

fs/ubifs/io.c

@@ -194,6 +194,24 @@ int ubifs_is_mapped(const struct ubifs_info *c, int lnum)
 	return err;
 }
 
+static void record_magic_error(struct ubifs_stats_info *stats)
+{
+	if (stats)
+		stats->magic_errors++;
+}
+
+static void record_node_error(struct ubifs_stats_info *stats)
+{
+	if (stats)
+		stats->node_errors++;
+}
+
+static void record_crc_error(struct ubifs_stats_info *stats)
+{
+	if (stats)
+		stats->crc_errors++;
+}
+
 /**
  * ubifs_check_node - check node.
  * @c: UBIFS file-system description object
@@ -238,6 +256,7 @@ int ubifs_check_node(const struct ubifs_info *c, const void *buf, int len,
 		if (!quiet)
 			ubifs_err(c, "bad magic %#08x, expected %#08x",
 				  magic, UBIFS_NODE_MAGIC);
+		record_magic_error(c->stats);
 		err = -EUCLEAN;
 		goto out;
 	}
@@ -246,6 +265,7 @@ int ubifs_check_node(const struct ubifs_info *c, const void *buf, int len,
 	if (type < 0 || type >= UBIFS_NODE_TYPES_CNT) {
 		if (!quiet)
 			ubifs_err(c, "bad node type %d", type);
+		record_node_error(c->stats);
 		goto out;
 	}
 
@@ -270,6 +290,7 @@ int ubifs_check_node(const struct ubifs_info *c, const void *buf, int len,
 		if (!quiet)
 			ubifs_err(c, "bad CRC: calculated %#08x, read %#08x",
 				  crc, node_crc);
+		record_crc_error(c->stats);
 		err = -EUCLEAN;
 		goto out;
 	}

fs/ubifs/replay.c

@@ -106,7 +106,7 @@ static int set_bud_lprops(struct ubifs_info *c, struct bud_entry *b)
 		 * property values should be @lp->free == @c->leb_size and
 		 * @lp->dirty == 0, but that is not the case. The reason is that
 		 * the LEB had been garbage collected before it became the bud,
-		 * and there was not commit inbetween. The garbage collector
+		 * and there was no commit in between. The garbage collector
 		 * resets the free and dirty space without recording it
 		 * anywhere except lprops, so if there was no commit then
 		 * lprops does not have that information.

fs/ubifs/super.c

@@ -1264,6 +1264,10 @@ static int mount_ubifs(struct ubifs_info *c)
 	if (err)
 		return err;
 
+	err = ubifs_sysfs_register(c);
+	if (err)
+		goto out_debugging;
+
 	err = check_volume_empty(c);
 	if (err)
 		goto out_free;
@@ -1367,15 +1371,14 @@ static int mount_ubifs(struct ubifs_info *c)
 	sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, c->vi.vol_id);
 	if (!c->ro_mount) {
 		/* Create background thread */
-		c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
+		c->bgt = kthread_run(ubifs_bg_thread, c, "%s", c->bgt_name);
 		if (IS_ERR(c->bgt)) {
 			err = PTR_ERR(c->bgt);
 			c->bgt = NULL;
 			ubifs_err(c, "cannot spawn \"%s\", error %d",
 				  c->bgt_name, err);
 			goto out_wbufs;
 		}
-		wake_up_process(c->bgt);
 	}
 
 	err = ubifs_read_master(c);
@@ -1641,6 +1644,8 @@ static int mount_ubifs(struct ubifs_info *c)
 	vfree(c->sbuf);
 	kfree(c->bottom_up_buf);
 	kfree(c->sup_node);
+	ubifs_sysfs_unregister(c);
+out_debugging:
 	ubifs_debugging_exit(c);
 	return err;
 }
@@ -1684,6 +1689,7 @@ static void ubifs_umount(struct ubifs_info *c)
 	kfree(c->bottom_up_buf);
 	kfree(c->sup_node);
 	ubifs_debugging_exit(c);
+	ubifs_sysfs_unregister(c);
 }
 
 /**
@@ -1780,15 +1786,14 @@ static int ubifs_remount_rw(struct ubifs_info *c)
 		goto out;
 
 	/* Create background thread */
-	c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
+	c->bgt = kthread_run(ubifs_bg_thread, c, "%s", c->bgt_name);
 	if (IS_ERR(c->bgt)) {
 		err = PTR_ERR(c->bgt);
 		c->bgt = NULL;
 		ubifs_err(c, "cannot spawn \"%s\", error %d",
 			  c->bgt_name, err);
 		goto out;
 	}
-	wake_up_process(c->bgt);
 
 	c->orph_buf = vmalloc(c->leb_size);
 	if (!c->orph_buf) {
@@ -1853,7 +1858,6 @@ static int ubifs_remount_rw(struct ubifs_info *c)
 		kthread_stop(c->bgt);
 		c->bgt = NULL;
 	}
-	free_wbufs(c);
 	kfree(c->write_reserve_buf);
 	c->write_reserve_buf = NULL;
 	vfree(c->ileb_buf);
@@ -2436,14 +2440,20 @@ static int __init ubifs_init(void)
 
 	dbg_debugfs_init();
 
+	err = ubifs_sysfs_init();
+	if (err)
+		goto out_dbg;
+
 	err = register_filesystem(&ubifs_fs_type);
 	if (err) {
 		pr_err("UBIFS error (pid %d): cannot register file system, error %d",
 		       current->pid, err);
-		goto out_dbg;
+		goto out_sysfs;
 	}
 	return 0;
 
+out_sysfs:
+	ubifs_sysfs_exit();
 out_dbg:
 	dbg_debugfs_exit();
 	ubifs_compressors_exit();
@@ -2462,6 +2472,7 @@ static void __exit ubifs_exit(void)
 	WARN_ON(atomic_long_read(&ubifs_clean_zn_cnt) != 0);
 
 	dbg_debugfs_exit();
+	ubifs_sysfs_exit();
 	ubifs_compressors_exit();
 	unregister_shrinker(&ubifs_shrinker_info);