| Message ID | 20210808162453.1653-2-pali@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fs: Remove usage of broken nls_utf8 and drop it | expand |
Pali Rohár <pali@kernel.org> writes: > Currently iocharset=utf8 mount option is broken and error is printed to > dmesg when it is used. To use UTF-8 as iocharset, it is required to use > utf8=1 mount option. > > Fix iocharset=utf8 mount option to use be equivalent to the utf8=1 mount > option and remove printing error from dmesg. This change is not equivalent to utf8=1. In the case of utf8=1, vfat uses iocharset's conversion table and it can handle more than ascii. So this patch is incompatible changes, and handles less chars than utf8=1. So I think this is clean though, but this would be regression for user of utf8=1. Thanks.
On Sunday 15 August 2021 12:42:47 OGAWA Hirofumi wrote: > Pali Rohár <pali@kernel.org> writes: > > > Currently iocharset=utf8 mount option is broken and error is printed to > > dmesg when it is used. To use UTF-8 as iocharset, it is required to use > > utf8=1 mount option. > > > > Fix iocharset=utf8 mount option to use be equivalent to the utf8=1 mount > > option and remove printing error from dmesg. > > This change is not equivalent to utf8=1. In the case of utf8=1, vfat > uses iocharset's conversion table and it can handle more than ascii. > > So this patch is incompatible changes, and handles less chars than > utf8=1. So I think this is clean though, but this would be regression > for user of utf8=1. I do not think so... But please correct me, as this code around is mess. Without this change when utf8=1 is set then iocharset= encoding is used for case-insensitivity implementation (toupper / tolower conversion). For all other parts are use correct utf8* conversion functions. But you use touppper / tolower functions from iocharset= encoding on stream of utf8 bytes then you either get identity or some unpredictable garbage in utf8. So when comparing two (different) non-ASCII filenames via this method you in most cases get that filenames are different. Because converting their utf8 bytes via toupper / tolower functions from iocharset= encoding results in two different byte sequences in most cases. Even for two utf8 case-insensitive same strings. But you can play with it and I guess it is possible to find two different utf8 strings which after toupper / tolower conversion from some iocharset= encoding would lead to same byte sequence. This patch uses for utf8 tolower / touppser function simple 7-bit tolower / toupper ascii function. And so for 7-bit ascii file names there is no change. So this patch changes behavior when comparing non 7-bit ascii file names, but only in cases when previously two different file names were marked as same. As now they are marked correctly as different. So this is changed behavior, but I guess it is bug fix which is needed. If you want I can put this change into separate patch. Issue that two case-insensitive same files are marked as different is not changed by this patch and therefore this issue stay here. > Thanks. > -- > OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
To: Pali Rohár <pali@kernel.org> Cc: 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>, "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: Re: [RFC PATCH 01/20] fat: Fix iocharset=utf8 mount option From: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Gcc: nnimap+ibmpc.myhome.or.jp:Sent --text follows this line-- To: Pali Rohár <pali@kernel.org> Cc: 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>, "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: Re: [RFC PATCH 01/20] fat: Fix iocharset=utf8 mount option From: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Gcc: nnimap+ibmpc.myhome.or.jp:Sent --text follows this line-- Pali Rohár <pali@kernel.org> writes: >> This change is not equivalent to utf8=1. In the case of utf8=1, vfat >> uses iocharset's conversion table and it can handle more than ascii. >> >> So this patch is incompatible changes, and handles less chars than >> utf8=1. So I think this is clean though, but this would be regression >> for user of utf8=1. > > I do not think so... But please correct me, as this code around is mess. > > Without this change when utf8=1 is set then iocharset= encoding is used > for case-insensitivity implementation (toupper / tolower conversion). > For all other parts are use correct utf8* conversion functions. > > But you use touppper / tolower functions from iocharset= encoding on > stream of utf8 bytes then you either get identity or some unpredictable > garbage in utf8. So when comparing two (different) non-ASCII filenames > via this method you in most cases get that filenames are different. > Because converting their utf8 bytes via toupper / tolower functions from > iocharset= encoding results in two different byte sequences in most > cases. Even for two utf8 case-insensitive same strings. > > But you can play with it and I guess it is possible to find two > different utf8 strings which after toupper / tolower conversion from > some iocharset= encoding would lead to same byte sequence. > > This patch uses for utf8 tolower / touppser function simple 7-bit > tolower / toupper ascii function. And so for 7-bit ascii file names > there is no change. > > So this patch changes behavior when comparing non 7-bit ascii file > names, but only in cases when previously two different file names were > marked as same. As now they are marked correctly as different. So this > is changed behavior, but I guess it is bug fix which is needed. > If you want I can put this change into separate patch. > > Issue that two case-insensitive same files are marked as different is > not changed by this patch and therefore this issue stay here. OK, sure. utf8 looks like broken than I was thinking (although user can use iocharset=ascii and utf8=1 for this). The code might be better to clean up a bit more though, looks like good basically. One thing, please update FAT_DEFAULT_IOCHARSET help in Kconfig and Documentation/filesystems/vfat.rst (with new warning about iocharset=utf8). Thanks.
On Sun, Aug 08, 2021 at 06:24:34PM +0200, Pali Rohár wrote: > Currently iocharset=utf8 mount option is broken and error is printed to > dmesg when it is used. To use UTF-8 as iocharset, it is required to use > utf8=1 mount option. > > Fix iocharset=utf8 mount option to use be equivalent to the utf8=1 mount > option and remove printing error from dmesg. > > FAT by definition is case-insensitive but current Linux implementation is > case-sensitive for non-ASCII characters when UTF-8 is used. This patch does > not change this UTF-8 behavior. Only more comments in fat_utf8_strnicmp() > function are added about it. > > After this patch iocharset=utf8 starts working, so there is no need to have > separate config option FAT_DEFAULT_UTF8 as FAT_DEFAULT_IOCHARSET for utf8 > also starts working. So remove redundant config option FAT_DEFAULT_UTF8. > > Signed-off-by: Pali Rohár <pali@kernel.org> > --- > fs/fat/Kconfig | 15 --------------- > fs/fat/dir.c | 17 +++++++---------- > fs/fat/fat.h | 22 ++++++++++++++++++++++ > fs/fat/inode.c | 28 +++++++++++----------------- > fs/fat/namei_vfat.c | 26 +++++++++++++++++++------- > 5 files changed, 59 insertions(+), 49 deletions(-) > > diff --git a/fs/fat/Kconfig b/fs/fat/Kconfig > index 66532a71e8fd..a31594137d5e 100644 > --- a/fs/fat/Kconfig > +++ b/fs/fat/Kconfig > @@ -100,18 +100,3 @@ config FAT_DEFAULT_IOCHARSET > > Enable any character sets you need in File Systems/Native Language > Support. > - > -config FAT_DEFAULT_UTF8 > - bool "Enable FAT UTF-8 option by default" > - depends on VFAT_FS > - default n > - help > - Set this if you would like to have "utf8" mount option set > - by default when mounting FAT filesystems. > - > - Even if you say Y here can always disable UTF-8 for > - particular mount by adding "utf8=0" to mount options. > - > - Say Y if you use UTF-8 encoding for file names, N otherwise. > - > - See <file:Documentation/filesystems/vfat.rst> for more information. > diff --git a/fs/fat/dir.c b/fs/fat/dir.c > index c4a274285858..49fe8dc6e5f0 100644 > --- a/fs/fat/dir.c > +++ b/fs/fat/dir.c > @@ -33,11 +33,6 @@ > #define FAT_MAX_UNI_CHARS ((MSDOS_SLOTS - 1) * 13 + 1) > #define FAT_MAX_UNI_SIZE (FAT_MAX_UNI_CHARS * sizeof(wchar_t)) > > -static inline unsigned char fat_tolower(unsigned char c) > -{ > - return ((c >= 'A') && (c <= 'Z')) ? c+32 : c; > -} > - > static inline loff_t fat_make_i_pos(struct super_block *sb, > struct buffer_head *bh, > struct msdos_dir_entry *de) > @@ -258,10 +253,12 @@ static inline int fat_name_match(struct msdos_sb_info *sbi, > if (a_len != b_len) > return 0; > > - if (sbi->options.name_check != 's') > - return !nls_strnicmp(sbi->nls_io, a, b, a_len); > - else > + if (sbi->options.name_check == 's') > return !memcmp(a, b, a_len); > + else if (sbi->options.utf8) > + return !fat_utf8_strnicmp(a, b, a_len); > + else > + return !nls_strnicmp(sbi->nls_io, a, b, a_len); > } > > enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, }; > @@ -384,7 +381,7 @@ static int fat_parse_short(struct super_block *sb, > de->lcase & CASE_LOWER_BASE); > if (chl <= 1) { > if (!isvfat) > - ptname[i] = nocase ? c : fat_tolower(c); > + ptname[i] = nocase ? c : fat_ascii_to_lower(c); > i++; > if (c != ' ') { > name_len = i; > @@ -421,7 +418,7 @@ static int fat_parse_short(struct super_block *sb, > if (chl <= 1) { > k++; > if (!isvfat) > - ptname[i] = nocase ? c : fat_tolower(c); > + ptname[i] = nocase ? c : fat_ascii_to_lower(c); > i++; > if (c != ' ') { > name_len = i; > diff --git a/fs/fat/fat.h b/fs/fat/fat.h > index 02d4d4234956..0cd15fb3b042 100644 > --- a/fs/fat/fat.h > +++ b/fs/fat/fat.h > @@ -310,6 +310,28 @@ static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len) > #endif > } > > +static inline unsigned char fat_ascii_to_lower(unsigned char c) > +{ > + return ((c >= 'A') && (c <= 'Z')) ? c+32 : c; > +} > + > +static inline int fat_utf8_strnicmp(const unsigned char *a, > + const unsigned char *b, > + int len) > +{ > + int i; > + > + /* > + * FIXME: UTF-8 doesn't provide FAT semantics > + * Case-insensitive support is only for 7-bit ASCII characters > + */ > + for (i = 0; i < len; i++) { > + if (fat_ascii_to_lower(a[i]) != fat_ascii_to_lower(b[i])) > + return 1; > + } > + return 0; > +} > + > /* fat/cache.c */ > extern void fat_cache_inval_inode(struct inode *inode); > extern int fat_get_cluster(struct inode *inode, int cluster, > diff --git a/fs/fat/inode.c b/fs/fat/inode.c > index de0c9b013a85..f8c8a739f8f0 100644 > --- a/fs/fat/inode.c > +++ b/fs/fat/inode.c > @@ -957,7 +957,9 @@ static int fat_show_options(struct seq_file *m, struct dentry *root) > /* strip "cp" prefix from displayed option */ > seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]); > if (isvfat) { > - if (sbi->nls_io) > + if (opts->utf8) > + seq_printf(m, ",iocharset=utf8"); checkpatch will probably warn you about this. WARNING: Prefer seq_puts to seq_printf > + else if (sbi->nls_io) > seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); > > switch (opts->shortname) { > @@ -994,8 +996,6 @@ static int fat_show_options(struct seq_file *m, struct dentry *root) > if (opts->nocase) > seq_puts(m, ",nocase"); > } else { > - if (opts->utf8) > - seq_puts(m, ",utf8"); > if (opts->unicode_xlate) > seq_puts(m, ",uni_xlate"); > if (!opts->numtail) > @@ -1157,8 +1157,6 @@ static int parse_options(struct super_block *sb, char *options, int is_vfat, > opts->errors = FAT_ERRORS_RO; > *debug = 0; > > - opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat; > - > if (!options) > goto out; > > @@ -1319,10 +1317,14 @@ static int parse_options(struct super_block *sb, char *options, int is_vfat, > | VFAT_SFN_CREATE_WIN95; > break; > case Opt_utf8_no: /* 0 or no or false */ > - opts->utf8 = 0; > + fat_reset_iocharset(opts); > break; > case Opt_utf8_yes: /* empty or 1 or yes or true */ > - opts->utf8 = 1; > + fat_reset_iocharset(opts); > + iocharset = kstrdup("utf8", GFP_KERNEL); > + if (!iocharset) > + return -ENOMEM; > + opts->iocharset = iocharset; > break; > case Opt_uni_xl_no: /* 0 or no or false */ > opts->unicode_xlate = 0; > @@ -1360,18 +1362,11 @@ static int parse_options(struct super_block *sb, char *options, int is_vfat, > } > > out: > - /* UTF-8 doesn't provide FAT semantics */ > - if (!strcmp(opts->iocharset, "utf8")) { > - fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset" > - " for FAT filesystems, filesystem will be " > - "case sensitive!"); > - } > + opts->utf8 = !strcmp(opts->iocharset, "utf8") && is_vfat; > > /* If user doesn't specify allow_utime, it's initialized from dmask. */ > if (opts->allow_utime == (unsigned short)-1) > opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH); > - if (opts->unicode_xlate) > - opts->utf8 = 0; > if (opts->nfs == FAT_NFS_NOSTALE_RO) { > sb->s_flags |= SB_RDONLY; > sb->s_export_op = &fat_export_ops_nostale; > @@ -1832,8 +1827,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, > goto out_fail; > } > > - /* FIXME: utf8 is using iocharset for upper/lower conversion */ > - if (sbi->options.isvfat) { > + if (sbi->options.isvfat && !sbi->options.utf8) { > sbi->nls_io = load_nls(sbi->options.iocharset); > if (!sbi->nls_io) { > fat_msg(sb, KERN_ERR, "IO charset %s not found", > diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c > index 5369d82e0bfb..efb3cb9ea8a8 100644 > --- a/fs/fat/namei_vfat.c > +++ b/fs/fat/namei_vfat.c > @@ -134,6 +134,7 @@ static int vfat_hash(const struct dentry *dentry, struct qstr *qstr) > static int vfat_hashi(const struct dentry *dentry, struct qstr *qstr) > { > struct nls_table *t = MSDOS_SB(dentry->d_sb)->nls_io; > + int utf8 = MSDOS_SB(dentry->d_sb)->options.utf8; > const unsigned char *name; > unsigned int len; > unsigned long hash; > @@ -142,8 +143,17 @@ static int vfat_hashi(const struct dentry *dentry, struct qstr *qstr) > len = vfat_striptail_len(qstr); > > hash = init_name_hash(dentry); > - while (len--) > - hash = partial_name_hash(nls_tolower(t, *name++), hash); > + if (utf8) { > + /* > + * FIXME: UTF-8 doesn't provide FAT semantics > + * Case-insensitive support is only for 7-bit ASCII characters > + */ > + while (len--) > + hash = partial_name_hash(fat_ascii_to_lower(*name++), hash); > + } else { > + while (len--) > + hash = partial_name_hash(nls_tolower(t, *name++), hash); > + } > qstr->hash = end_name_hash(hash); > > return 0; > @@ -156,16 +166,18 @@ static int vfat_cmpi(const struct dentry *dentry, > unsigned int len, const char *str, const struct qstr *name) > { > struct nls_table *t = MSDOS_SB(dentry->d_sb)->nls_io; > + int utf8 = MSDOS_SB(dentry->d_sb)->options.utf8; > unsigned int alen, blen; > > /* A filename cannot end in '.' or we treat it like it has none */ > alen = vfat_striptail_len(name); > blen = __vfat_striptail_len(len, str); > - if (alen == blen) { > - if (nls_strnicmp(t, name->name, str, alen) == 0) > - return 0; > - } > - return 1; > + if (alen != blen) > + return 1; > + else if (utf8) > + return fat_utf8_strnicmp(name->name, str, alen); > + else > + return nls_strnicmp(t, name->name, str, alen); > } > > /* > -- > 2.20.1 >
diff --git a/fs/fat/Kconfig b/fs/fat/Kconfig index 66532a71e8fd..a31594137d5e 100644 --- a/fs/fat/Kconfig +++ b/fs/fat/Kconfig @@ -100,18 +100,3 @@ config FAT_DEFAULT_IOCHARSET Enable any character sets you need in File Systems/Native Language Support. - -config FAT_DEFAULT_UTF8 - bool "Enable FAT UTF-8 option by default" - depends on VFAT_FS - default n - help - Set this if you would like to have "utf8" mount option set - by default when mounting FAT filesystems. - - Even if you say Y here can always disable UTF-8 for - particular mount by adding "utf8=0" to mount options. - - Say Y if you use UTF-8 encoding for file names, N otherwise. - - See <file:Documentation/filesystems/vfat.rst> for more information. diff --git a/fs/fat/dir.c b/fs/fat/dir.c index c4a274285858..49fe8dc6e5f0 100644 --- a/fs/fat/dir.c +++ b/fs/fat/dir.c @@ -33,11 +33,6 @@ #define FAT_MAX_UNI_CHARS ((MSDOS_SLOTS - 1) * 13 + 1) #define FAT_MAX_UNI_SIZE (FAT_MAX_UNI_CHARS * sizeof(wchar_t)) -static inline unsigned char fat_tolower(unsigned char c) -{ - return ((c >= 'A') && (c <= 'Z')) ? c+32 : c; -} - static inline loff_t fat_make_i_pos(struct super_block *sb, struct buffer_head *bh, struct msdos_dir_entry *de) @@ -258,10 +253,12 @@ static inline int fat_name_match(struct msdos_sb_info *sbi, if (a_len != b_len) return 0; - if (sbi->options.name_check != 's') - return !nls_strnicmp(sbi->nls_io, a, b, a_len); - else + if (sbi->options.name_check == 's') return !memcmp(a, b, a_len); + else if (sbi->options.utf8) + return !fat_utf8_strnicmp(a, b, a_len); + else + return !nls_strnicmp(sbi->nls_io, a, b, a_len); } enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, }; @@ -384,7 +381,7 @@ static int fat_parse_short(struct super_block *sb, de->lcase & CASE_LOWER_BASE); if (chl <= 1) { if (!isvfat) - ptname[i] = nocase ? c : fat_tolower(c); + ptname[i] = nocase ? c : fat_ascii_to_lower(c); i++; if (c != ' ') { name_len = i; @@ -421,7 +418,7 @@ static int fat_parse_short(struct super_block *sb, if (chl <= 1) { k++; if (!isvfat) - ptname[i] = nocase ? c : fat_tolower(c); + ptname[i] = nocase ? c : fat_ascii_to_lower(c); i++; if (c != ' ') { name_len = i; diff --git a/fs/fat/fat.h b/fs/fat/fat.h index 02d4d4234956..0cd15fb3b042 100644 --- a/fs/fat/fat.h +++ b/fs/fat/fat.h @@ -310,6 +310,28 @@ static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len) #endif } +static inline unsigned char fat_ascii_to_lower(unsigned char c) +{ + return ((c >= 'A') && (c <= 'Z')) ? c+32 : c; +} + +static inline int fat_utf8_strnicmp(const unsigned char *a, + const unsigned char *b, + int len) +{ + int i; + + /* + * FIXME: UTF-8 doesn't provide FAT semantics + * Case-insensitive support is only for 7-bit ASCII characters + */ + for (i = 0; i < len; i++) { + if (fat_ascii_to_lower(a[i]) != fat_ascii_to_lower(b[i])) + return 1; + } + return 0; +} + /* fat/cache.c */ extern void fat_cache_inval_inode(struct inode *inode); extern int fat_get_cluster(struct inode *inode, int cluster, diff --git a/fs/fat/inode.c b/fs/fat/inode.c index de0c9b013a85..f8c8a739f8f0 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -957,7 +957,9 @@ static int fat_show_options(struct seq_file *m, struct dentry *root) /* strip "cp" prefix from displayed option */ seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]); if (isvfat) { - if (sbi->nls_io) + if (opts->utf8) + seq_printf(m, ",iocharset=utf8"); + else if (sbi->nls_io) seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); switch (opts->shortname) { @@ -994,8 +996,6 @@ static int fat_show_options(struct seq_file *m, struct dentry *root) if (opts->nocase) seq_puts(m, ",nocase"); } else { - if (opts->utf8) - seq_puts(m, ",utf8"); if (opts->unicode_xlate) seq_puts(m, ",uni_xlate"); if (!opts->numtail) @@ -1157,8 +1157,6 @@ static int parse_options(struct super_block *sb, char *options, int is_vfat, opts->errors = FAT_ERRORS_RO; *debug = 0; - opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat; - if (!options) goto out; @@ -1319,10 +1317,14 @@ static int parse_options(struct super_block *sb, char *options, int is_vfat, | VFAT_SFN_CREATE_WIN95; break; case Opt_utf8_no: /* 0 or no or false */ - opts->utf8 = 0; + fat_reset_iocharset(opts); break; case Opt_utf8_yes: /* empty or 1 or yes or true */ - opts->utf8 = 1; + fat_reset_iocharset(opts); + iocharset = kstrdup("utf8", GFP_KERNEL); + if (!iocharset) + return -ENOMEM; + opts->iocharset = iocharset; break; case Opt_uni_xl_no: /* 0 or no or false */ opts->unicode_xlate = 0; @@ -1360,18 +1362,11 @@ static int parse_options(struct super_block *sb, char *options, int is_vfat, } out: - /* UTF-8 doesn't provide FAT semantics */ - if (!strcmp(opts->iocharset, "utf8")) { - fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset" - " for FAT filesystems, filesystem will be " - "case sensitive!"); - } + opts->utf8 = !strcmp(opts->iocharset, "utf8") && is_vfat; /* If user doesn't specify allow_utime, it's initialized from dmask. */ if (opts->allow_utime == (unsigned short)-1) opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH); - if (opts->unicode_xlate) - opts->utf8 = 0; if (opts->nfs == FAT_NFS_NOSTALE_RO) { sb->s_flags |= SB_RDONLY; sb->s_export_op = &fat_export_ops_nostale; @@ -1832,8 +1827,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, goto out_fail; } - /* FIXME: utf8 is using iocharset for upper/lower conversion */ - if (sbi->options.isvfat) { + if (sbi->options.isvfat && !sbi->options.utf8) { sbi->nls_io = load_nls(sbi->options.iocharset); if (!sbi->nls_io) { fat_msg(sb, KERN_ERR, "IO charset %s not found", diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c index 5369d82e0bfb..efb3cb9ea8a8 100644 --- a/fs/fat/namei_vfat.c +++ b/fs/fat/namei_vfat.c @@ -134,6 +134,7 @@ static int vfat_hash(const struct dentry *dentry, struct qstr *qstr) static int vfat_hashi(const struct dentry *dentry, struct qstr *qstr) { struct nls_table *t = MSDOS_SB(dentry->d_sb)->nls_io; + int utf8 = MSDOS_SB(dentry->d_sb)->options.utf8; const unsigned char *name; unsigned int len; unsigned long hash; @@ -142,8 +143,17 @@ static int vfat_hashi(const struct dentry *dentry, struct qstr *qstr) len = vfat_striptail_len(qstr); hash = init_name_hash(dentry); - while (len--) - hash = partial_name_hash(nls_tolower(t, *name++), hash); + if (utf8) { + /* + * FIXME: UTF-8 doesn't provide FAT semantics + * Case-insensitive support is only for 7-bit ASCII characters + */ + while (len--) + hash = partial_name_hash(fat_ascii_to_lower(*name++), hash); + } else { + while (len--) + hash = partial_name_hash(nls_tolower(t, *name++), hash); + } qstr->hash = end_name_hash(hash); return 0; @@ -156,16 +166,18 @@ static int vfat_cmpi(const struct dentry *dentry, unsigned int len, const char *str, const struct qstr *name) { struct nls_table *t = MSDOS_SB(dentry->d_sb)->nls_io; + int utf8 = MSDOS_SB(dentry->d_sb)->options.utf8; unsigned int alen, blen; /* A filename cannot end in '.' or we treat it like it has none */ alen = vfat_striptail_len(name); blen = __vfat_striptail_len(len, str); - if (alen == blen) { - if (nls_strnicmp(t, name->name, str, alen) == 0) - return 0; - } - return 1; + if (alen != blen) + return 1; + else if (utf8) + return fat_utf8_strnicmp(name->name, str, alen); + else + return nls_strnicmp(t, name->name, str, alen); } /*
Currently iocharset=utf8 mount option is broken and error is printed to dmesg when it is used. To use UTF-8 as iocharset, it is required to use utf8=1 mount option. Fix iocharset=utf8 mount option to use be equivalent to the utf8=1 mount option and remove printing error from dmesg. FAT by definition is case-insensitive but current Linux implementation is case-sensitive for non-ASCII characters when UTF-8 is used. This patch does not change this UTF-8 behavior. Only more comments in fat_utf8_strnicmp() function are added about it. After this patch iocharset=utf8 starts working, so there is no need to have separate config option FAT_DEFAULT_UTF8 as FAT_DEFAULT_IOCHARSET for utf8 also starts working. So remove redundant config option FAT_DEFAULT_UTF8. Signed-off-by: Pali Rohár <pali@kernel.org> --- fs/fat/Kconfig | 15 --------------- fs/fat/dir.c | 17 +++++++---------- fs/fat/fat.h | 22 ++++++++++++++++++++++ fs/fat/inode.c | 28 +++++++++++----------------- fs/fat/namei_vfat.c | 26 +++++++++++++++++++------- 5 files changed, 59 insertions(+), 49 deletions(-)