1 files changed, 58 insertions, 105 deletions

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 4de1f61bba76..286f8fcb74cc 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1391,62 +1391,11 @@ static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
 }
 
 #if IS_ENABLED(CONFIG_UNICODE)
-/*
- * Test whether a case-insensitive directory entry matches the filename
- * being searched for.  If quick is set, assume the name being looked up
- * is already in the casefolded form.
- *
- * Returns: 0 if the directory entry matches, more than 0 if it
- * doesn't match or less than zero on error.
- */
-static int ext4_ci_compare(const struct inode *parent, const struct qstr *name,
-			   u8 *de_name, size_t de_name_len, bool quick)
-{
-	const struct super_block *sb = parent->i_sb;
-	const struct unicode_map *um = sb->s_encoding;
-	struct fscrypt_str decrypted_name = FSTR_INIT(NULL, de_name_len);
-	struct qstr entry = QSTR_INIT(de_name, de_name_len);
-	int ret;
-
-	if (IS_ENCRYPTED(parent)) {
-		const struct fscrypt_str encrypted_name =
-				FSTR_INIT(de_name, de_name_len);
-
-		decrypted_name.name = kmalloc(de_name_len, GFP_KERNEL);
-		if (!decrypted_name.name)
-			return -ENOMEM;
-		ret = fscrypt_fname_disk_to_usr(parent, 0, 0, &encrypted_name,
-						&decrypted_name);
-		if (ret < 0)
-			goto out;
-		entry.name = decrypted_name.name;
-		entry.len = decrypted_name.len;
-	}
-
-	if (quick)
-		ret = utf8_strncasecmp_folded(um, name, &entry);
-	else
-		ret = utf8_strncasecmp(um, name, &entry);
-	if (ret < 0) {
-		/* Handle invalid character sequence as either an error
-		 * or as an opaque byte sequence.
-		 */
-		if (sb_has_strict_encoding(sb))
-			ret = -EINVAL;
-		else if (name->len != entry.len)
-			ret = 1;
-		else
-			ret = !!memcmp(name->name, entry.name, entry.len);
-	}
-out:
-	kfree(decrypted_name.name);
-	return ret;
-}
-
 int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
 				  struct ext4_filename *name)
 {
-	struct fscrypt_str *cf_name = &name->cf_name;
+	struct qstr *cf_name = &name->cf_name;
+	unsigned char *buf;
 	struct dx_hash_info *hinfo = &name->hinfo;
 	int len;
 
@@ -1456,18 +1405,18 @@ int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
 		return 0;
 	}
 
-	cf_name->name = kmalloc(EXT4_NAME_LEN, GFP_NOFS);
-	if (!cf_name->name)
+	buf = kmalloc(EXT4_NAME_LEN, GFP_NOFS);
+	if (!buf)
 		return -ENOMEM;
 
-	len = utf8_casefold(dir->i_sb->s_encoding,
-			    iname, cf_name->name,
-			    EXT4_NAME_LEN);
+	len = utf8_casefold(dir->i_sb->s_encoding, iname, buf, EXT4_NAME_LEN);
 	if (len <= 0) {
-		kfree(cf_name->name);
-		cf_name->name = NULL;
+		kfree(buf);
+		buf = NULL;
 	}
+	cf_name->name = buf;
 	cf_name->len = (unsigned) len;
+
 	if (!IS_ENCRYPTED(dir))
 		return 0;
 
@@ -1503,22 +1452,29 @@ static bool ext4_match(struct inode *parent,
 #if IS_ENABLED(CONFIG_UNICODE)
 	if (IS_CASEFOLDED(parent) &&
 	    (!IS_ENCRYPTED(parent) || fscrypt_has_encryption_key(parent))) {
-		if (fname->cf_name.name) {
-			struct qstr cf = {.name = fname->cf_name.name,
-					  .len = fname->cf_name.len};
-			if (IS_ENCRYPTED(parent)) {
-				if (fname->hinfo.hash != EXT4_DIRENT_HASH(de) ||
-					fname->hinfo.minor_hash !=
-						EXT4_DIRENT_MINOR_HASH(de)) {
-
-					return false;
-				}
-			}
-			return !ext4_ci_compare(parent, &cf, de->name,
-							de->name_len, true);
-		}
-		return !ext4_ci_compare(parent, fname->usr_fname, de->name,
-						de->name_len, false);
+		/*
+		 * Just checking IS_ENCRYPTED(parent) below is not
+		 * sufficient to decide whether one can use the hash for
+		 * skipping the string comparison, because the key might
+		 * have been added right after
+		 * ext4_fname_setup_ci_filename().  In this case, a hash
+		 * mismatch will be a false negative.  Therefore, make
+		 * sure cf_name was properly initialized before
+		 * considering the calculated hash.
+		 */
+		if (IS_ENCRYPTED(parent) && fname->cf_name.name &&
+		    (fname->hinfo.hash != EXT4_DIRENT_HASH(de) ||
+		     fname->hinfo.minor_hash != EXT4_DIRENT_MINOR_HASH(de)))
+			return false;
+		/*
+		 * Treat comparison errors as not a match.  The
+		 * only case where it happens is on a disk
+		 * corruption or ENOMEM.
+		 */
+
+		return generic_ci_match(parent, fname->usr_fname,
+					&fname->cf_name, de->name,
+					de->name_len) > 0;
 	}
 #endif
 
@@ -1618,7 +1574,7 @@ static struct buffer_head *__ext4_find_entry(struct inode *dir,
 					     &has_inline_data);
 		if (inlined)
 			*inlined = has_inline_data;
-		if (has_inline_data)
+		if (has_inline_data || IS_ERR(ret))
 			goto cleanup_and_exit;
 	}
 
@@ -1765,7 +1721,6 @@ static struct buffer_head *ext4_lookup_entry(struct inode *dir,
 	struct buffer_head *bh;
 
 	err = ext4_fname_prepare_lookup(dir, dentry, &fname);
-	generic_set_encrypted_ci_d_ops(dentry);
 	if (err == -ENOENT)
 		return NULL;
 	if (err)
@@ -1873,8 +1828,7 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsi
 		}
 	}
 
-#if IS_ENABLED(CONFIG_UNICODE)
-	if (!inode && IS_CASEFOLDED(dir)) {
+	if (IS_ENABLED(CONFIG_UNICODE) && !inode && IS_CASEFOLDED(dir)) {
 		/* Eventually we want to call d_add_ci(dentry, NULL)
 		 * for negative dentries in the encoding case as
 		 * well.  For now, prevent the negative dentry
@@ -1882,7 +1836,7 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsi
 		 */
 		return NULL;
 	}
-#endif
+
 	return d_splice_alias(inode, dentry);
 }
 
@@ -2041,7 +1995,7 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
 	 * split it in half by count; each resulting block will have at least
 	 * half the space free.
 	 */
-	if (i > 0)
+	if (i >= 0)
 		split = count - move;
 	else
 		split = count/2;
@@ -2210,7 +2164,7 @@ static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
 	 * happen is that the times are slightly out of date
 	 * and/or different from the directory change time.
 	 */
-	dir->i_mtime = inode_set_ctime_current(dir);
+	inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
 	ext4_update_dx_flag(dir);
 	inode_inc_iversion(dir);
 	err2 = ext4_mark_inode_dirty(handle, dir);
@@ -2329,8 +2283,7 @@ static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
 	top = data2 + len;
 	while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) {
 		if (ext4_check_dir_entry(dir, NULL, de, bh2, data2, len,
-					 (data2 + (blocksize - csum_size) -
-					  (char *) de))) {
+					(char *)de - data2)) {
 			brelse(bh2);
 			brelse(bh);
 			return -EFSCORRUPTED;
@@ -2438,8 +2391,6 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
 
 	sb = dir->i_sb;
 	blocksize = sb->s_blocksize;
-	if (!dentry->d_name.len)
-		return -EINVAL;
 
 	if (fscrypt_is_nokey_name(dentry))
 		return -ENOKEY;
@@ -3248,7 +3199,7 @@ static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
 	 * recovery. */
 	inode->i_size = 0;
 	ext4_orphan_add(handle, inode);
-	dir->i_mtime = inode_set_ctime_current(dir);
+	inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
 	inode_set_ctime_current(inode);
 	retval = ext4_mark_inode_dirty(handle, inode);
 	if (retval)
@@ -3258,16 +3209,14 @@ static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
 	ext4_fc_track_unlink(handle, dentry);
 	retval = ext4_mark_inode_dirty(handle, dir);
 
-#if IS_ENABLED(CONFIG_UNICODE)
 	/* VFS negative dentries are incompatible with Encoding and
 	 * Case-insensitiveness. Eventually we'll want avoid
 	 * invalidating the dentries here, alongside with returning the
 	 * negative dentries at ext4_lookup(), when it is better
 	 * supported by the VFS for the CI case.
 	 */
-	if (IS_CASEFOLDED(dir))
+	if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir))
 		d_invalidate(dentry);
-#endif
 
 end_rmdir:
 	brelse(bh);
@@ -3323,7 +3272,7 @@ int __ext4_unlink(struct inode *dir, const struct qstr *d_name,
 		retval = ext4_delete_entry(handle, dir, de, bh);
 		if (retval)
 			goto out_handle;
-		dir->i_mtime = inode_set_ctime_current(dir);
+		inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
 		ext4_update_dx_flag(dir);
 		retval = ext4_mark_inode_dirty(handle, dir);
 		if (retval)
@@ -3369,16 +3318,15 @@ static int ext4_unlink(struct inode *dir, struct dentry *dentry)
 		goto out_trace;
 
 	retval = __ext4_unlink(dir, &dentry->d_name, d_inode(dentry), dentry);
-#if IS_ENABLED(CONFIG_UNICODE)
+
 	/* VFS negative dentries are incompatible with Encoding and
 	 * Case-insensitiveness. Eventually we'll want avoid
 	 * invalidating the dentries here, alongside with returning the
 	 * negative dentries at ext4_lookup(), when it is  better
 	 * supported by the VFS for the CI case.
 	 */
-	if (IS_CASEFOLDED(dir))
+	if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir))
 		d_invalidate(dentry);
-#endif
 
 out_trace:
 	trace_ext4_unlink_exit(dentry, retval);
@@ -3635,10 +3583,14 @@ struct ext4_renament {
 	int dir_inlined;
 };
 
-static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent)
+static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent, bool is_cross)
 {
 	int retval;
 
+	ent->is_dir = true;
+	if (!is_cross)
+		return 0;
+
 	ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
 					      &retval, &ent->parent_de,
 					      &ent->dir_inlined);
@@ -3656,6 +3608,9 @@ static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
 {
 	int retval;
 
+	if (!ent->dir_bh)
+		return 0;
+
 	ent->parent_de->inode = cpu_to_le32(dir_ino);
 	BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
 	if (!ent->dir_inlined) {
@@ -3691,7 +3646,7 @@ static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
 	if (ext4_has_feature_filetype(ent->dir->i_sb))
 		ent->de->file_type = file_type;
 	inode_inc_iversion(ent->dir);
-	ent->dir->i_mtime = inode_set_ctime_current(ent->dir);
+	inode_set_mtime_to_ts(ent->dir, inode_set_ctime_current(ent->dir));
 	retval = ext4_mark_inode_dirty(handle, ent->dir);
 	BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
 	if (!ent->inlined) {
@@ -3944,7 +3899,7 @@ static int ext4_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 			if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
 				goto end_rename;
 		}
-		retval = ext4_rename_dir_prepare(handle, &old);
+		retval = ext4_rename_dir_prepare(handle, &old, new.dir != old.dir);
 		if (retval)
 			goto end_rename;
 	}
@@ -4006,9 +3961,9 @@ static int ext4_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 		ext4_dec_count(new.inode);
 		inode_set_ctime_current(new.inode);
 	}
-	old.dir->i_mtime = inode_set_ctime_current(old.dir);
+	inode_set_mtime_to_ts(old.dir, inode_set_ctime_current(old.dir));
 	ext4_update_dx_flag(old.dir);
-	if (old.dir_bh) {
+	if (old.is_dir) {
 		retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
 		if (retval)
 			goto end_rename;
@@ -4031,7 +3986,7 @@ static int ext4_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 	if (unlikely(retval))
 		goto end_rename;
 
-	if (S_ISDIR(old.inode->i_mode)) {
+	if (old.is_dir) {
 		/*
 		 * We disable fast commits here that's because the
 		 * replay code is not yet capable of changing dot dot
@@ -4158,14 +4113,12 @@ static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
 		ext4_handle_sync(handle);
 
 	if (S_ISDIR(old.inode->i_mode)) {
-		old.is_dir = true;
-		retval = ext4_rename_dir_prepare(handle, &old);
+		retval = ext4_rename_dir_prepare(handle, &old, new.dir != old.dir);
 		if (retval)
 			goto end_rename;
 	}
 	if (S_ISDIR(new.inode->i_mode)) {
-		new.is_dir = true;
-		retval = ext4_rename_dir_prepare(handle, &new);
+		retval = ext4_rename_dir_prepare(handle, &new, new.dir != old.dir);
 		if (retval)
 			goto end_rename;
 	}