Merge tag 'fscrypt_for_linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt

Pull fscrypt updates from Ted Ts'o:
 "Clean up fscrypt's dcache revalidation support, and other
  miscellaneous cleanups"

* tag 'fscrypt_for_linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt:
  fscrypt: cache decrypted symlink target in ->i_link
  vfs: use READ_ONCE() to access ->i_link
  fscrypt: fix race where ->lookup() marks plaintext dentry as ciphertext
  fscrypt: only set dentry_operations on ciphertext dentries
  fs, fscrypt: clear DCACHE_ENCRYPTED_NAME when unaliasing directory
  fscrypt: fix race allowing rename() and link() of ciphertext dentries
  fscrypt: clean up and improve dentry revalidation
  fscrypt: use READ_ONCE() to access ->i_crypt_info
  fscrypt: remove WARN_ON_ONCE() when decryption fails
  fscrypt: drop inode argument from fscrypt_get_ctx()

4 files changed, 101 insertions, 40 deletions

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index ef755e5f6f2f..1cb67859e051 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2303,23 +2303,47 @@ extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
 
 #ifdef CONFIG_FS_ENCRYPTION
+static inline void ext4_fname_from_fscrypt_name(struct ext4_filename *dst,
+						const struct fscrypt_name *src)
+{
+	memset(dst, 0, sizeof(*dst));
+
+	dst->usr_fname = src->usr_fname;
+	dst->disk_name = src->disk_name;
+	dst->hinfo.hash = src->hash;
+	dst->hinfo.minor_hash = src->minor_hash;
+	dst->crypto_buf = src->crypto_buf;
+}
+
 static inline int ext4_fname_setup_filename(struct inode *dir,
-			const struct qstr *iname,
-			int lookup, struct ext4_filename *fname)
+					    const struct qstr *iname,
+					    int lookup,
+					    struct ext4_filename *fname)
 {
 	struct fscrypt_name name;
 	int err;
 
-	memset(fname, 0, sizeof(struct ext4_filename));
-
 	err = fscrypt_setup_filename(dir, iname, lookup, &name);
+	if (err)
+		return err;
 
-	fname->usr_fname = name.usr_fname;
-	fname->disk_name = name.disk_name;
-	fname->hinfo.hash = name.hash;
-	fname->hinfo.minor_hash = name.minor_hash;
-	fname->crypto_buf = name.crypto_buf;
-	return err;
+	ext4_fname_from_fscrypt_name(fname, &name);
+	return 0;
+}
+
+static inline int ext4_fname_prepare_lookup(struct inode *dir,
+					    struct dentry *dentry,
+					    struct ext4_filename *fname)
+{
+	struct fscrypt_name name;
+	int err;
+
+	err = fscrypt_prepare_lookup(dir, dentry, &name);
+	if (err)
+		return err;
+
+	ext4_fname_from_fscrypt_name(fname, &name);
+	return 0;
 }
 
 static inline void ext4_fname_free_filename(struct ext4_filename *fname)
@@ -2333,19 +2357,27 @@ static inline void ext4_fname_free_filename(struct ext4_filename *fname)
 	fname->usr_fname = NULL;
 	fname->disk_name.name = NULL;
 }
-#else
+#else /* !CONFIG_FS_ENCRYPTION */
 static inline int ext4_fname_setup_filename(struct inode *dir,
-		const struct qstr *iname,
-		int lookup, struct ext4_filename *fname)
+					    const struct qstr *iname,
+					    int lookup,
+					    struct ext4_filename *fname)
 {
 	fname->usr_fname = iname;
 	fname->disk_name.name = (unsigned char *) iname->name;
 	fname->disk_name.len = iname->len;
 	return 0;
 }
-static inline void ext4_fname_free_filename(struct ext4_filename *fname) { }
 
-#endif
+static inline int ext4_fname_prepare_lookup(struct inode *dir,
+					    struct dentry *dentry,
+					    struct ext4_filename *fname)
+{
+	return ext4_fname_setup_filename(dir, &dentry->d_name, 1, fname);
+}
+
+static inline void ext4_fname_free_filename(struct ext4_filename *fname) { }
+#endif /* !CONFIG_FS_ENCRYPTION */
 
 /* dir.c */
 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index e917830eae84..6d50f53b7a15 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1371,7 +1371,7 @@ static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
 }
 
 /*
- *	ext4_find_entry()
+ *	__ext4_find_entry()
  *
  * finds an entry in the specified directory with the wanted name. It
  * returns the cache buffer in which the entry was found, and the entry
@@ -1381,39 +1381,32 @@ static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
  * The returned buffer_head has ->b_count elevated.  The caller is expected
  * to brelse() it when appropriate.
  */
-static struct buffer_head * ext4_find_entry (struct inode *dir,
-					const struct qstr *d_name,
-					struct ext4_dir_entry_2 **res_dir,
-					int *inlined)
+static struct buffer_head *__ext4_find_entry(struct inode *dir,
+					     struct ext4_filename *fname,
+					     struct ext4_dir_entry_2 **res_dir,
+					     int *inlined)
 {
 	struct super_block *sb;
 	struct buffer_head *bh_use[NAMEI_RA_SIZE];
 	struct buffer_head *bh, *ret = NULL;
 	ext4_lblk_t start, block;
-	const u8 *name = d_name->name;
+	const u8 *name = fname->usr_fname->name;
 	size_t ra_max = 0;	/* Number of bh's in the readahead
 				   buffer, bh_use[] */
 	size_t ra_ptr = 0;	/* Current index into readahead
 				   buffer */
 	ext4_lblk_t  nblocks;
 	int i, namelen, retval;
-	struct ext4_filename fname;
 
 	*res_dir = NULL;
 	sb = dir->i_sb;
-	namelen = d_name->len;
+	namelen = fname->usr_fname->len;
 	if (namelen > EXT4_NAME_LEN)
 		return NULL;
 
-	retval = ext4_fname_setup_filename(dir, d_name, 1, &fname);
-	if (retval == -ENOENT)
-		return NULL;
-	if (retval)
-		return ERR_PTR(retval);
-
 	if (ext4_has_inline_data(dir)) {
 		int has_inline_data = 1;
-		ret = ext4_find_inline_entry(dir, &fname, res_dir,
+		ret = ext4_find_inline_entry(dir, fname, res_dir,
 					     &has_inline_data);
 		if (has_inline_data) {
 			if (inlined)
@@ -1433,7 +1426,7 @@ static struct buffer_head * ext4_find_entry (struct inode *dir,
 		goto restart;
 	}
 	if (is_dx(dir)) {
-		ret = ext4_dx_find_entry(dir, &fname, res_dir);
+		ret = ext4_dx_find_entry(dir, fname, res_dir);
 		/*
 		 * On success, or if the error was file not found,
 		 * return.  Otherwise, fall back to doing a search the
@@ -1497,7 +1490,7 @@ restart:
 			goto cleanup_and_exit;
 		}
 		set_buffer_verified(bh);
-		i = search_dirblock(bh, dir, &fname,
+		i = search_dirblock(bh, dir, fname,
 			    block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
 		if (i == 1) {
 			EXT4_I(dir)->i_dir_start_lookup = block;
@@ -1528,10 +1521,50 @@ cleanup_and_exit:
 	/* Clean up the read-ahead blocks */
 	for (; ra_ptr < ra_max; ra_ptr++)
 		brelse(bh_use[ra_ptr]);
-	ext4_fname_free_filename(&fname);
 	return ret;
 }
 
+static struct buffer_head *ext4_find_entry(struct inode *dir,
+					   const struct qstr *d_name,
+					   struct ext4_dir_entry_2 **res_dir,
+					   int *inlined)
+{
+	int err;
+	struct ext4_filename fname;
+	struct buffer_head *bh;
+
+	err = ext4_fname_setup_filename(dir, d_name, 1, &fname);
+	if (err == -ENOENT)
+		return NULL;
+	if (err)
+		return ERR_PTR(err);
+
+	bh = __ext4_find_entry(dir, &fname, res_dir, inlined);
+
+	ext4_fname_free_filename(&fname);
+	return bh;
+}
+
+static struct buffer_head *ext4_lookup_entry(struct inode *dir,
+					     struct dentry *dentry,
+					     struct ext4_dir_entry_2 **res_dir)
+{
+	int err;
+	struct ext4_filename fname;
+	struct buffer_head *bh;
+
+	err = ext4_fname_prepare_lookup(dir, dentry, &fname);
+	if (err == -ENOENT)
+		return NULL;
+	if (err)
+		return ERR_PTR(err);
+
+	bh = __ext4_find_entry(dir, &fname, res_dir, NULL);
+
+	ext4_fname_free_filename(&fname);
+	return bh;
+}
+
 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 			struct ext4_filename *fname,
 			struct ext4_dir_entry_2 **res_dir)
@@ -1590,16 +1623,11 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsi
 	struct inode *inode;
 	struct ext4_dir_entry_2 *de;
 	struct buffer_head *bh;
-	int err;
-
-	err = fscrypt_prepare_lookup(dir, dentry, flags);
-	if (err)
-		return ERR_PTR(err);
 
 	if (dentry->d_name.len > EXT4_NAME_LEN)
 		return ERR_PTR(-ENAMETOOLONG);
 
-	bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
+	bh = ext4_lookup_entry(dir, dentry, &de);
 	if (IS_ERR(bh))
 		return ERR_CAST(bh);
 	inode = NULL;
diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c
index 2a39c7cb1441..c916017db334 100644
--- a/fs/ext4/readpage.c
+++ b/fs/ext4/readpage.c
@@ -244,7 +244,7 @@ int ext4_mpage_readpages(struct address_space *mapping,
 			struct fscrypt_ctx *ctx = NULL;
 
 			if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode)) {
-				ctx = fscrypt_get_ctx(inode, GFP_NOFS);
+				ctx = fscrypt_get_ctx(GFP_NOFS);
 				if (IS_ERR(ctx))
 					goto set_error_page;
 			}
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 3681cb737e9d..f71b5254a990 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1113,6 +1113,7 @@ static int ext4_drop_inode(struct inode *inode)
 
 static void ext4_free_in_core_inode(struct inode *inode)
 {
+	fscrypt_free_inode(inode);
 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 }