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authorDuane Griffin <duaneg@dghda.com>2007-07-15 23:41:22 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-16 09:05:49 -0700
commit1e96b7ca1e8f17c5117da369daaa7cf2edfdf9b1 (patch)
treee770e898c43bc1e24bec330d97ef26c4f49189f8
parent29bc5b4f73a65ef667df50d5ed474e371471d915 (diff)
downloadlinux-bcache-1e96b7ca1e8f17c5117da369daaa7cf2edfdf9b1.tar.zst
HFS+: refactor ASCII to unicode conversion routine for later reuse
The HFS+ filesystem is case-insensitive and does automatic unicode decomposition by default, but does not provide custom dentry operations. This can lead to multiple dentries being cached for lookups on a filename with varying case and/or character (de)composition. These patches add custom dentry hash and comparison operations for case-sensitive and/or automatically decomposing HFS+ filesystems. Unicode decomposition and case-folding are performed as required to ensure equivalent filenames are hashed to the same values and compare as equal. This patch: Refactor existing HFS+ ASCII to unicode string conversion routine to split out character conversion functionality. This will be reused by the custom dentry hash and comparison routines. This approach avoids unnecessary memory allocation compared to using the string conversion routine directly in the new functions. [akpm@linux-foundation.org: avoid use-of-uninitialised] Signed-off-by: Duane Griffin <duaneg@dghda.com> Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/hfsplus/unicode.c107
1 files changed, 62 insertions, 45 deletions
diff --git a/fs/hfsplus/unicode.c b/fs/hfsplus/unicode.c
index 689c8bd721fb..5df0052b2775 100644
--- a/fs/hfsplus/unicode.c
+++ b/fs/hfsplus/unicode.c
@@ -239,58 +239,75 @@ out:
return res;
}
-int hfsplus_asc2uni(struct super_block *sb, struct hfsplus_unistr *ustr, const char *astr, int len)
+/*
+ * Convert one or more ASCII characters into a single unicode character.
+ * Returns the number of ASCII characters corresponding to the unicode char.
+ */
+static inline int asc2unichar(struct super_block *sb, const char *astr, int len,
+ wchar_t *uc)
{
- struct nls_table *nls = HFSPLUS_SB(sb).nls;
- int size, off, decompose;
+ int size = HFSPLUS_SB(sb).nls->char2uni(astr, len, uc);
+ if (size <= 0) {
+ *uc = '?';
+ size = 1;
+ }
+ switch (*uc) {
+ case 0x2400:
+ *uc = 0;
+ break;
+ case ':':
+ *uc = '/';
+ break;
+ }
+ return size;
+}
+
+/* Decomposes a single unicode character. */
+static inline u16 *decompose_unichar(wchar_t uc, int *size)
+{
+ int off;
+
+ off = hfsplus_decompose_table[(uc >> 12) & 0xf];
+ if (off == 0 || off == 0xffff)
+ return NULL;
+
+ off = hfsplus_decompose_table[off + ((uc >> 8) & 0xf)];
+ if (!off)
+ return NULL;
+
+ off = hfsplus_decompose_table[off + ((uc >> 4) & 0xf)];
+ if (!off)
+ return NULL;
+
+ off = hfsplus_decompose_table[off + (uc & 0xf)];
+ *size = off & 3;
+ if (*size == 0)
+ return NULL;
+ return hfsplus_decompose_table + (off / 4);
+}
+
+int hfsplus_asc2uni(struct super_block *sb, struct hfsplus_unistr *ustr,
+ const char *astr, int len)
+{
+ int size, dsize, decompose;
+ u16 *dstr, outlen = 0;
wchar_t c;
- u16 outlen = 0;
decompose = !(HFSPLUS_SB(sb).flags & HFSPLUS_SB_NODECOMPOSE);
-
while (outlen < HFSPLUS_MAX_STRLEN && len > 0) {
- size = nls->char2uni(astr, len, &c);
- if (size <= 0) {
- c = '?';
- size = 1;
- }
- astr += size;
- len -= size;
- switch (c) {
- case 0x2400:
- c = 0;
- break;
- case ':':
- c = '/';
- break;
- }
- if (c >= 0xc0 && decompose) {
- off = hfsplus_decompose_table[(c >> 12) & 0xf];
- if (!off)
- goto done;
- if (off == 0xffff) {
- goto done;
- }
- off = hfsplus_decompose_table[off + ((c >> 8) & 0xf)];
- if (!off)
- goto done;
- off = hfsplus_decompose_table[off + ((c >> 4) & 0xf)];
- if (!off)
- goto done;
- off = hfsplus_decompose_table[off + (c & 0xf)];
- size = off & 3;
- if (!size)
- goto done;
- off /= 4;
- if (outlen + size > HFSPLUS_MAX_STRLEN)
+ size = asc2unichar(sb, astr, len, &c);
+
+ if (decompose && (dstr = decompose_unichar(c, &dsize))) {
+ if (outlen + dsize > HFSPLUS_MAX_STRLEN)
break;
do {
- ustr->unicode[outlen++] = cpu_to_be16(hfsplus_decompose_table[off++]);
- } while (--size > 0);
- continue;
- }
- done:
- ustr->unicode[outlen++] = cpu_to_be16(c);
+ ustr->unicode[outlen++] = cpu_to_be16(*dstr++);
+ } while (--dsize > 0);
+ } else
+ ustr->unicode[outlen++] = cpu_to_be16(c);
+
+ astr += size;
+ len -= size;
}
ustr->length = cpu_to_be16(outlen);
if (len > 0)