From nobody Sat Apr 5 15:41:20 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1737282779041242.52309174161348; Sun, 19 Jan 2025 02:32:59 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tZSbR-0001Tz-FC; Sun, 19 Jan 2025 05:32:25 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tZSbM-0001Sx-Ks; Sun, 19 Jan 2025 05:32:20 -0500 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tZSbK-0005AJ-Qk; Sun, 19 Jan 2025 05:32:20 -0500 Received: from localhost.tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by isrv.corpit.ru (Postfix) with ESMTP id 81E79DAF65; Sun, 19 Jan 2025 13:32:02 +0300 (MSK) Received: by localhost.tls.msk.ru (Postfix, from userid 1000) id EB99850B7E; Sun, 19 Jan 2025 13:32:13 +0300 (MSK) From: Michael Tokarev Date: Sun, 19 Jan 2025 13:29:05 +0300 Subject: [PATCH] vvfat: create_long_filename(): refresh To: qemu-devel@nongnu.org, =?UTF-8?q?Volker=20R=C3=BCmelin?= Cc: Pierrick Bouvier , qemu-block@nongnu.org, qemu-trivial@nongnu.org Message-Id: <20250119103213.EB99850B7E@localhost.tls.msk.ru> Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1737282785359019000 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" add comments explaining what is going on (since long file names are really = weird), rewrite the second loop to do one UTF16 char at a time instead of byte, and fix coding style. Signed-off-by: Michael Tokarev --- block/vvfat.c | 54 +++++++++++++++++++++++++++++---------------------- 1 file changed, 31 insertions(+), 23 deletions(-) on top of the previous patch diff --git a/block/vvfat.c b/block/vvfat.c index b53e3b452b..4827288756 100644 --- a/block/vvfat.c +++ b/block/vvfat.c @@ -401,7 +401,7 @@ static void init_mbr(BDRVVVFATState *s, int cyls, int h= eads, int secs) =20 static direntry_t *create_long_filename(BDRVVVFATState *s, const char *fil= ename) { - int number_of_entries, i; + unsigned nents, i; glong length; =20 gunichar2 *longname =3D g_utf8_to_utf16(filename, -1, NULL, &length, N= ULL); @@ -410,31 +410,39 @@ static direntry_t *create_long_filename(BDRVVVFATStat= e *s, const char *filename) return NULL; } =20 - number_of_entries =3D DIV_ROUND_UP(length * 2, 26); - - for(i=3D0;idirectory)); - entry->attributes=3D0xf; - entry->reserved[0]=3D0; - entry->begin=3D0; - entry->name[0]=3D(number_of_entries-i)|(i=3D=3D0?0x40:0); - } - for(i=3D0;i<26*number_of_entries;i++) { - unsigned char *entry=3Darray_get(&(s->directory),s->directory.next= -1-(i/26)); - int offset=3D(i%26); - if(offset<10) offset=3D1+offset; - else if(offset<22) offset=3D14+offset-10; - else offset=3D28+offset-22; - if (i >=3D 2 * length + 2) { - entry[offset] =3D 0xff; - } else if (i % 2 =3D=3D 0) { - entry[offset] =3D longname[i / 2] & 0xff; - } else { - entry[offset] =3D longname[i / 2] >> 8; + /* + * long file name is split into multiple directory entries, + * 13 UTF16 chars (26 bytes) in each, + * in reverse order. + */ + nents =3D DIV_ROUND_UP(length, 13); + + for (i =3D 0; i < nents; ++i) { /* allocate and basic init */ + direntry_t *entry =3D array_get_next(&s->directory); + entry->attributes =3D 0xf; + entry->reserved[0] =3D 0; + entry->begin =3D 0; + entry->name[0] =3D (nents - i) | (i =3D=3D 0 ? 0x40 : 0); + } + + /* write 13 chars of name to each entry, entries in reverse order */ + for (i =3D 0; i < nents * 13; ++i) { + unsigned char *entry =3D + array_get(&s->directory, s->directory.next - 1 - i / 13); + unsigned off =3D i % 13; + /* each entry has 3 different places for the name: */ + off =3D off < 5 ? off * 2 + 1 /* bytes 1..10, 5 chars 0..4, unalig= ned */ + : off < 11 ? (off - 5) * 2 + 14 /* bytes 14..25, 6 chars 5..10= */ + : (off - 11) * 2 + 28; /* bytes 28..31, 2 chars 11.= .12 */ + if (i <=3D length) { /* name and trailing U+0000 */ + entry[off + 0] =3D longname[i] & 0xff; + entry[off + 1] =3D longname[i] >> 8; + } else { /* fill remaining parts with U+FFFF */ + entry[off + 0] =3D entry[off + 1] =3D 0xff; } } g_free(longname); - return array_get(&(s->directory),s->directory.next-number_of_entries); + return array_get(&s->directory, s->directory.next - nents); } =20 static char is_free(const direntry_t* direntry) --=20 2.39.5