From: "Pali Rohár" <pali@kernel.org> To: linux-fsdevel@vger.kernel.org, linux-ntfs-dev@lists.sourceforge.net, linux-cifs@vger.kernel.org, jfs-discussion@lists.sourceforge.net, linux-kernel@vger.kernel.org, "Alexander Viro" <viro@zeniv.linux.org.uk>, "Jan Kara" <jack@suse.cz>, "OGAWA Hirofumi" <hirofumi@mail.parknet.co.jp>, "Theodore Y . Ts'o" <tytso@mit.edu>, "Luis de Bethencourt" <luisbg@kernel.org>, "Salah Triki" <salah.triki@gmail.com>, "Andrew Morton" <akpm@linux-foundation.org>, "Dave Kleikamp" <shaggy@kernel.org>, "Anton Altaparmakov" <anton@tuxera.com>, "Pavel Machek" <pavel@ucw.cz>, "Marek Behún" <marek.behun@nic.cz>, "Christoph Hellwig" <hch@infradead.org> Subject: [RFC PATCH 11/20] hfs: Explicitly set hsb->nls_disk when hsb->nls_io is set Date: Sun, 8 Aug 2021 18:24:44 +0200 [thread overview] Message-ID: <20210808162453.1653-12-pali@kernel.org> (raw) In-Reply-To: <20210808162453.1653-1-pali@kernel.org> It does not make any sense to set hsb->nls_io (NLS iocharset used between VFS and hfs driver) when hsb->nls_disk (NLS codepage used between hfs driver and disk) is not set. Reverse engineering driver code shown what is doing in this special case: When codepage was not defined but iocharset was then hfs driver copied 8bit character from disk directly to 16bit unicode wchar_t type. Which means it did conversion from Latin1 (ISO-8859-1) to Unicode because first 256 Unicode code points matches 8bit ISO-8859-1 codepage table. So when iocharset was specified and codepage not, then codepage used implicit value "iso8859-1". So when hsb->nls_disk is not set and hsb->nls_io is then explicitly set hsb->nls_disk to "iso8859-1". Such setup is obviously incompatible with Mac OS systems as they do not support iso8859-1 encoding for hfs. So print warning into dmesg about this fact. After this change hsb->nls_disk is always set, so remove code paths for case when hsb->nls_disk was not set as they are not needed anymore. Signed-off-by: Pali Rohár <pali@kernel.org> --- fs/hfs/super.c | 31 +++++++++++++++++++++++++++++++ fs/hfs/trans.c | 38 ++++++++++++++------------------------ 2 files changed, 45 insertions(+), 24 deletions(-) diff --git a/fs/hfs/super.c b/fs/hfs/super.c index 12d9bae39363..86bc46746c7f 100644 --- a/fs/hfs/super.c +++ b/fs/hfs/super.c @@ -351,6 +351,37 @@ static int parse_options(char *options, struct hfs_sb_info *hsb) } } + if (hsb->nls_io && !hsb->nls_disk) { + /* + * Previous version of hfs driver did something unexpected: + * When codepage was not defined but iocharset was then + * hfs driver copied 8bit character from disk directly to + * 16bit unicode wchar_t type. Which means it did conversion + * from Latin1 (ISO-8859-1) to Unicode because first 256 + * Unicode code points matches 8bit ISO-8859-1 codepage table. + * So when iocharset was specified and codepage not, then + * codepage used implicit value "iso8859-1". + * + * To not change this previous default behavior as some users + * may depend on it, we load iso8859-1 NLS table explicitly + * to simplify code and make it more reable what happens. + * + * In context of hfs driver it is really strange to use + * ISO-8859-1 codepage table for storing data to disk, but + * nothing forbids it. Just it is highly incompatible with + * Mac OS systems. So via pr_warn() inform user that this + * is not probably what he wants. + */ + pr_warn("iocharset was specified but codepage not, " + "using default codepage=iso8859-1\n"); + pr_warn("this default codepage=iso8859-1 is incompatible with " + "Mac OS systems and may be changed in the future"); + hsb->nls_disk = load_nls("iso8859-1"); + if (!hsb->nls_disk) { + pr_err("unable to load iso8859-1 codepage\n"); + return 0; + } + } if (hsb->nls_disk && !hsb->nls_io) { hsb->nls_io = load_nls_default(); if (!hsb->nls_io) { diff --git a/fs/hfs/trans.c b/fs/hfs/trans.c index 39f5e343bf4d..c75682c61b06 100644 --- a/fs/hfs/trans.c +++ b/fs/hfs/trans.c @@ -48,18 +48,13 @@ int hfs_mac2asc(struct super_block *sb, char *out, const struct hfs_name *in) wchar_t ch; while (srclen > 0) { - if (nls_disk) { - size = nls_disk->char2uni(src, srclen, &ch); - if (size <= 0) { - ch = '?'; - size = 1; - } - src += size; - srclen -= size; - } else { - ch = *src++; - srclen--; + size = nls_disk->char2uni(src, srclen, &ch); + if (size <= 0) { + ch = '?'; + size = 1; } + src += size; + srclen -= size; if (ch == '/') ch = ':'; size = nls_io->uni2char(ch, dst, dstlen); @@ -119,20 +114,15 @@ void hfs_asc2mac(struct super_block *sb, struct hfs_name *out, const struct qstr srclen -= size; if (ch == ':') ch = '/'; - if (nls_disk) { - size = nls_disk->uni2char(ch, dst, dstlen); - if (size < 0) { - if (size == -ENAMETOOLONG) - goto out; - *dst = '?'; - size = 1; - } - dst += size; - dstlen -= size; - } else { - *dst++ = ch > 0xff ? '?' : ch; - dstlen--; + size = nls_disk->uni2char(ch, dst, dstlen); + if (size < 0) { + if (size == -ENAMETOOLONG) + goto out; + *dst = '?'; + size = 1; } + dst += size; + dstlen -= size; } } else { char ch; -- 2.20.1
next prev parent reply other threads:[~2021-08-08 16:26 UTC|newest] Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-08-08 16:24 [RFC PATCH 00/20] fs: Remove usage of broken nls_utf8 and drop it Pali Rohár 2021-08-08 16:24 ` [RFC PATCH 01/20] fat: Fix iocharset=utf8 mount option Pali Rohár 2021-08-15 3:42 ` OGAWA Hirofumi 2021-08-15 9:42 ` Pali Rohár 2021-08-15 11:23 ` OGAWA Hirofumi 2021-08-23 3:51 ` Kari Argillander 2021-08-08 16:24 ` [RFC PATCH 02/20] hfsplus: Add iocharset= mount option as alias for nls= Pali Rohár 2021-08-09 17:51 ` Viacheslav Dubeyko 2021-08-09 20:49 ` Kari Argillander 2021-08-09 21:25 ` Pali Rohár 2021-08-08 16:24 ` [RFC PATCH 03/20] udf: Fix iocharset=utf8 mount option Pali Rohár 2021-08-12 14:17 ` Jan Kara 2021-08-12 15:51 ` Pali Rohár 2021-08-13 13:48 ` Jan Kara 2021-08-19 8:34 ` Pali Rohár 2021-08-19 10:41 ` Jan Kara 2021-08-08 16:24 ` [RFC PATCH 04/20] isofs: joliet: " Pali Rohár 2021-08-12 14:18 ` Jan Kara 2021-08-08 16:24 ` [RFC PATCH 05/20] ntfs: Undeprecate iocharset= " Pali Rohár 2021-08-09 20:52 ` Kari Argillander 2021-08-19 1:21 ` Kari Argillander 2021-08-19 8:12 ` Pali Rohár 2021-08-19 10:23 ` Kari Argillander 2021-08-19 22:04 ` Pali Rohár 2021-08-19 23:18 ` Kari Argillander 2021-08-08 16:24 ` [RFC PATCH 06/20] ntfs: Fix error processing when load_nls() fails Pali Rohár 2021-08-08 16:24 ` [RFC PATCH 07/20] befs: Fix printing iocharset= mount option Pali Rohár 2021-08-08 16:24 ` [RFC PATCH 08/20] befs: Rename enum value Opt_charset to Opt_iocharset to match " Pali Rohár 2021-08-08 16:24 ` [RFC PATCH 09/20] befs: Fix error processing when load_nls() fails Pali Rohár 2021-08-08 16:24 ` [RFC PATCH 10/20] befs: Allow to use native UTF-8 mode Pali Rohár 2021-08-08 16:24 ` Pali Rohár [this message] 2021-08-09 17:31 ` [RFC PATCH 11/20] hfs: Explicitly set hsb->nls_disk when hsb->nls_io is set Viacheslav Dubeyko 2021-08-09 17:37 ` Matthew Wilcox 2021-08-09 17:47 ` Pali Rohár 2021-08-09 20:43 ` Steve French 2021-08-09 18:00 ` Viacheslav Dubeyko 2021-08-08 16:24 ` [RFC PATCH 12/20] hfs: Do not use broken utf8 NLS table for iocharset=utf8 mount option Pali Rohár 2021-08-09 17:49 ` Viacheslav Dubeyko 2021-08-08 16:24 ` [RFC PATCH 13/20] hfsplus: " Pali Rohár 2021-08-09 17:42 ` Viacheslav Dubeyko 2021-08-08 16:24 ` [RFC PATCH 14/20] jfs: Remove custom iso8859-1 implementation Pali Rohár 2021-08-08 16:24 ` [RFC PATCH 15/20] jfs: Fix buffer overflow in jfs_strfromUCS_le() function Pali Rohár 2021-08-08 16:24 ` [RFC PATCH 16/20] jfs: Do not use broken utf8 NLS table for iocharset=utf8 mount option Pali Rohár 2021-08-08 16:24 ` [RFC PATCH 17/20] ntfs: " Pali Rohár 2021-08-08 16:24 ` [RFC PATCH 18/20] cifs: " Pali Rohár 2021-08-08 16:24 ` [RFC PATCH 19/20] cifs: Remove usage of load_nls_default() calls Pali Rohár 2021-08-08 16:24 ` [RFC PATCH 20/20] nls: Drop broken nls_utf8 module Pali Rohár 2021-09-03 21:26 ` [RFC PATCH 00/20] fs: Remove usage of broken nls_utf8 and drop it Kari Argillander 2021-09-03 21:37 ` Pali Rohár 2021-09-03 22:06 ` Kari Argillander
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