Merge tag 'upstream-4.20-rc7' of git://git.infradead.org/linux-ubifs

Pull UBI/UBIFS fixes from Richard Weinberger:

 - Kconfig dependency fixes for our new auth feature

 - Fix for selecting the right compressor when creating a fs

 - Bugfix for a bug in UBIFS's O_TMPFILE implementation

 - Refcounting fixes for UBI

* tag 'upstream-4.20-rc7' of git://git.infradead.org/linux-ubifs:
  ubifs: Handle re-linking of inodes correctly while recovery
  ubi: Do not drop UBI device reference before using
  ubi: Put MTD device after it is not used
  ubifs: Fix default compression selection in ubifs
  ubifs: Fix memory leak on error condition
  ubifs: auth: Add CONFIG_KEYS dependency
  ubifs: CONFIG_UBIFS_FS_AUTHENTICATION should depend on UBIFS_FS
  ubifs: replay: Fix high stack usage

4 files changed, 87 insertions, 26 deletions

diff --git a/fs/ubifs/Kconfig b/fs/ubifs/Kconfig
index 529856fbccd0..bc1e082d921d 100644
--- a/fs/ubifs/Kconfig
+++ b/fs/ubifs/Kconfig
@@ -12,9 +12,10 @@ config UBIFS_FS
 	help
 	  UBIFS is a file system for flash devices which works on top of UBI.
 
+if UBIFS_FS
+
 config UBIFS_FS_ADVANCED_COMPR
 	bool "Advanced compression options"
-	depends on UBIFS_FS
 	help
 	  This option allows to explicitly choose which compressions, if any,
 	  are enabled in UBIFS. Removing compressors means inability to read
@@ -24,7 +25,6 @@ config UBIFS_FS_ADVANCED_COMPR
 
 config UBIFS_FS_LZO
 	bool "LZO compression support" if UBIFS_FS_ADVANCED_COMPR
-	depends on UBIFS_FS
 	default y
 	help
 	   LZO compressor is generally faster than zlib but compresses worse.
@@ -32,14 +32,12 @@ config UBIFS_FS_LZO
 
 config UBIFS_FS_ZLIB
 	bool "ZLIB compression support" if UBIFS_FS_ADVANCED_COMPR
-	depends on UBIFS_FS
 	default y
 	help
 	  Zlib compresses better than LZO but it is slower. Say 'Y' if unsure.
 
 config UBIFS_ATIME_SUPPORT
-	bool "Access time support" if UBIFS_FS
-	depends on UBIFS_FS
+	bool "Access time support"
 	default n
 	help
 	  Originally UBIFS did not support atime, because it looked like a bad idea due
@@ -54,7 +52,6 @@ config UBIFS_ATIME_SUPPORT
 
 config UBIFS_FS_XATTR
 	bool "UBIFS XATTR support"
-	depends on UBIFS_FS
 	default y
 	help
 	  Saying Y here includes support for extended attributes (xattrs).
@@ -65,7 +62,7 @@ config UBIFS_FS_XATTR
 
 config UBIFS_FS_ENCRYPTION
 	bool "UBIFS Encryption"
-	depends on UBIFS_FS && UBIFS_FS_XATTR && BLOCK
+	depends on UBIFS_FS_XATTR && BLOCK
 	select FS_ENCRYPTION
 	default n
 	help
@@ -76,7 +73,7 @@ config UBIFS_FS_ENCRYPTION
 
 config UBIFS_FS_SECURITY
 	bool "UBIFS Security Labels"
-	depends on UBIFS_FS && UBIFS_FS_XATTR
+	depends on UBIFS_FS_XATTR
 	default y
 	help
 	  Security labels provide an access control facility to support Linux
@@ -89,6 +86,7 @@ config UBIFS_FS_SECURITY
 
 config UBIFS_FS_AUTHENTICATION
 	bool "UBIFS authentication support"
+	depends on KEYS
 	select CRYPTO_HMAC
 	help
 	  Enable authentication support for UBIFS. This feature offers protection
@@ -96,3 +94,5 @@ config UBIFS_FS_AUTHENTICATION
 	  If you say yes here you should also select a hashing algorithm such as
 	  sha256, these are not selected automatically since there are many
 	  different options.
+
+endif # UBIFS_FS
diff --git a/fs/ubifs/lpt.c b/fs/ubifs/lpt.c
index d1d5e96350dd..b0c5f06128b5 100644
--- a/fs/ubifs/lpt.c
+++ b/fs/ubifs/lpt.c
@@ -1675,6 +1675,12 @@ int ubifs_lpt_calc_hash(struct ubifs_info *c, u8 *hash)
 	if (!ubifs_authenticated(c))
 		return 0;
 
+	if (!c->nroot) {
+		err = ubifs_read_nnode(c, NULL, 0);
+		if (err)
+			return err;
+	}
+
 	desc = ubifs_hash_get_desc(c);
 	if (IS_ERR(desc))
 		return PTR_ERR(desc);
@@ -1685,12 +1691,6 @@ int ubifs_lpt_calc_hash(struct ubifs_info *c, u8 *hash)
 		goto out;
 	}
 
-	if (!c->nroot) {
-		err = ubifs_read_nnode(c, NULL, 0);
-		if (err)
-			return err;
-	}
-
 	cnode = (struct ubifs_cnode *)c->nroot;
 
 	while (cnode) {
diff --git a/fs/ubifs/replay.c b/fs/ubifs/replay.c
index 75f961c4c044..0a0e65c07c6d 100644
--- a/fs/ubifs/replay.c
+++ b/fs/ubifs/replay.c
@@ -213,6 +213,38 @@ static int trun_remove_range(struct ubifs_info *c, struct replay_entry *r)
 }
 
 /**
+ * inode_still_linked - check whether inode in question will be re-linked.
+ * @c: UBIFS file-system description object
+ * @rino: replay entry to test
+ *
+ * O_TMPFILE files can be re-linked, this means link count goes from 0 to 1.
+ * This case needs special care, otherwise all references to the inode will
+ * be removed upon the first replay entry of an inode with link count 0
+ * is found.
+ */
+static bool inode_still_linked(struct ubifs_info *c, struct replay_entry *rino)
+{
+	struct replay_entry *r;
+
+	ubifs_assert(c, rino->deletion);
+	ubifs_assert(c, key_type(c, &rino->key) == UBIFS_INO_KEY);
+
+	/*
+	 * Find the most recent entry for the inode behind @rino and check
+	 * whether it is a deletion.
+	 */
+	list_for_each_entry_reverse(r, &c->replay_list, list) {
+		ubifs_assert(c, r->sqnum >= rino->sqnum);
+		if (key_inum(c, &r->key) == key_inum(c, &rino->key))
+			return r->deletion == 0;
+
+	}
+
+	ubifs_assert(c, 0);
+	return false;
+}
+
+/**
  * apply_replay_entry - apply a replay entry to the TNC.
  * @c: UBIFS file-system description object
  * @r: replay entry to apply
@@ -239,6 +271,11 @@ static int apply_replay_entry(struct ubifs_info *c, struct replay_entry *r)
 			{
 				ino_t inum = key_inum(c, &r->key);
 
+				if (inode_still_linked(c, r)) {
+					err = 0;
+					break;
+				}
+
 				err = ubifs_tnc_remove_ino(c, inum);
 				break;
 			}
@@ -533,6 +570,28 @@ static int is_last_bud(struct ubifs_info *c, struct ubifs_bud *bud)
 	return data == 0xFFFFFFFF;
 }
 
+/* authenticate_sleb_hash and authenticate_sleb_hmac are split out for stack usage */
+static int authenticate_sleb_hash(struct ubifs_info *c, struct shash_desc *log_hash, u8 *hash)
+{
+	SHASH_DESC_ON_STACK(hash_desc, c->hash_tfm);
+
+	hash_desc->tfm = c->hash_tfm;
+	hash_desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+	ubifs_shash_copy_state(c, log_hash, hash_desc);
+	return crypto_shash_final(hash_desc, hash);
+}
+
+static int authenticate_sleb_hmac(struct ubifs_info *c, u8 *hash, u8 *hmac)
+{
+	SHASH_DESC_ON_STACK(hmac_desc, c->hmac_tfm);
+
+	hmac_desc->tfm = c->hmac_tfm;
+	hmac_desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+	return crypto_shash_digest(hmac_desc, hash, c->hash_len, hmac);
+}
+
 /**
  * authenticate_sleb - authenticate one scan LEB
  * @c: UBIFS file-system description object
@@ -574,21 +633,12 @@ static int authenticate_sleb(struct ubifs_info *c, struct ubifs_scan_leb *sleb,
 
 		if (snod->type == UBIFS_AUTH_NODE) {
 			struct ubifs_auth_node *auth = snod->node;
-			SHASH_DESC_ON_STACK(hash_desc, c->hash_tfm);
-			SHASH_DESC_ON_STACK(hmac_desc, c->hmac_tfm);
-
-			hash_desc->tfm = c->hash_tfm;
-			hash_desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 
-			ubifs_shash_copy_state(c, log_hash, hash_desc);
-			err = crypto_shash_final(hash_desc, hash);
+			err = authenticate_sleb_hash(c, log_hash, hash);
 			if (err)
 				goto out;
 
-			hmac_desc->tfm = c->hmac_tfm;
-			hmac_desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
-			err = crypto_shash_digest(hmac_desc, hash, c->hash_len,
-						  hmac);
+			err = authenticate_sleb_hmac(c, hash, hmac);
 			if (err)
 				goto out;
 
diff --git a/fs/ubifs/sb.c b/fs/ubifs/sb.c
index 75a69dd26d6e..3da90c951c23 100644
--- a/fs/ubifs/sb.c
+++ b/fs/ubifs/sb.c
@@ -63,6 +63,17 @@
 /* Default time granularity in nanoseconds */
 #define DEFAULT_TIME_GRAN 1000000000
 
+static int get_default_compressor(struct ubifs_info *c)
+{
+	if (ubifs_compr_present(c, UBIFS_COMPR_LZO))
+		return UBIFS_COMPR_LZO;
+
+	if (ubifs_compr_present(c, UBIFS_COMPR_ZLIB))
+		return UBIFS_COMPR_ZLIB;
+
+	return UBIFS_COMPR_NONE;
+}
+
 /**
  * create_default_filesystem - format empty UBI volume.
  * @c: UBIFS file-system description object
@@ -207,7 +218,7 @@ static int create_default_filesystem(struct ubifs_info *c)
 	if (c->mount_opts.override_compr)
 		sup->default_compr = cpu_to_le16(c->mount_opts.compr_type);
 	else
-		sup->default_compr = cpu_to_le16(UBIFS_COMPR_LZO);
+		sup->default_compr = cpu_to_le16(get_default_compressor(c));
 
 	generate_random_uuid(sup->uuid);