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[Qemu-devel] [PATCH 10/13] vvfat: correctly generate numeric-tail of sho
From: |
Hervé Poussineau |
Subject: |
[Qemu-devel] [PATCH 10/13] vvfat: correctly generate numeric-tail of short file names |
Date: |
Mon, 15 May 2017 22:31:10 +0200 |
More specifically:
- try without numeric-tail only if LFN didn't have invalid short chars
- start at ~1 (instead of ~0)
- handle case if numeric tail is more than one char (ie > 10)
Windows 9x Scandisk doesn't see anymore mismatches between short file names and
long file names for non-ASCII filenames.
Specification: "FAT: General overview of on-disk format" v1.03, page 31
Signed-off-by: Hervé Poussineau <address@hidden>
---
block/vvfat.c | 67 +++++++++++++++++++++++++++++++----------------------------
1 file changed, 35 insertions(+), 32 deletions(-)
diff --git a/block/vvfat.c b/block/vvfat.c
index 37cfaa85fc..98978df404 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -602,11 +602,14 @@ static uint8_t to_valid_short_char(uint8_t c)
}
}
-static direntry_t *create_short_filename(BDRVVVFATState *s, long_file_name
*lfn)
+static direntry_t *create_short_filename(BDRVVVFATState *s, long_file_name
*lfn,
+ unsigned int directory_start)
{
int i, j = 0;
direntry_t *entry = array_get_next(&(s->directory));
uint8_t c;
+ bool lossy_conversion = false;
+ char tail[11];
if (!entry) {
return NULL;
@@ -621,6 +624,8 @@ static direntry_t *create_short_filename(BDRVVVFATState *s,
long_file_name *lfn)
} else if (lfn->name[i + 1] == 0 &&
(lfn->name[i] == '.' || lfn->name[i] == 0)) {
break;
+ } else {
+ lossy_conversion = true;
}
}
/* search last extension */
@@ -637,10 +642,37 @@ static direntry_t *create_short_filename(BDRVVVFATState
*s, long_file_name *lfn)
entry->name[j++] = c;
} else if (lfn->name[i + 1] == 0 && lfn->name[i] == 0) {
break;
+ } else {
+ lossy_conversion = true;
}
}
}
- return entry;
+
+ /* numeric-tail generation */
+ for (j = 0; j < 8; j++) {
+ if (entry->name[j] == ' ') {
+ break;
+ }
+ }
+ for (i = lossy_conversion ? 1 : 0; i < 999999; i++) {
+ direntry_t *entry1;
+ if (i > 0) {
+ int len = sprintf(tail, "~%d", i);
+ memcpy(entry->name + MIN(j, 8 - len), tail, len);
+ }
+ for (entry1 = array_get(&(s->directory), directory_start);
+ entry1 < entry; entry1++) {
+ if (!is_long_name(entry1) &&
+ !memcmp(entry1->name, entry->name, 11)) {
+ break; /* found dupe */
+ }
+ }
+ if (entry1 == entry) {
+ /* no dupe found */
+ return entry;
+ }
+ }
+ return NULL;
}
/* fat functions */
@@ -754,36 +786,7 @@ static inline direntry_t*
create_short_and_long_name(BDRVVVFATState* s,
}
entry_long = create_long_filename(s, filename, &lfn);
- entry = create_short_filename(s, &lfn);
-
- /* mangle duplicates */
- while(1) {
- direntry_t* entry1=array_get(&(s->directory),directory_start);
- int j;
-
- for(;entry1<entry;entry1++)
- if(!is_long_name(entry1) && !memcmp(entry1->name,entry->name,11))
- break; /* found dupe */
- if(entry1==entry) /* no dupe found */
- break;
-
- /* use all 8 characters of name */
- if(entry->name[7]==' ') {
- int j;
- for(j=6;j>0 && entry->name[j]==' ';j--)
- entry->name[j]='~';
- }
-
- /* increment number */
- for(j=7;j>0 && entry->name[j]=='9';j--)
- entry->name[j]='0';
- if(j>0) {
- if(entry->name[j]<'0' || entry->name[j]>'9')
- entry->name[j]='0';
- else
- entry->name[j]++;
- }
- }
+ entry = create_short_filename(s, &lfn, directory_start);
/* calculate checksum; propagate to long name */
if(entry_long) {
--
2.11.0
- [Qemu-devel] [PATCH 00/13] vvfat: misc fixes for read-only mode, Hervé Poussineau, 2017/05/15
- [Qemu-devel] [PATCH 01/13] vvfat: fix qemu-img map and qemu-img convert, Hervé Poussineau, 2017/05/15
- [Qemu-devel] [PATCH 07/13] vvfat: always create . and .. entries at first and in that order, Hervé Poussineau, 2017/05/15
- [Qemu-devel] [PATCH 08/13] vvfat: correctly create long names for non-ASCII filenames, Hervé Poussineau, 2017/05/15
- [Qemu-devel] [PATCH 10/13] vvfat: correctly generate numeric-tail of short file names,
Hervé Poussineau <=
- [Qemu-devel] [PATCH 06/13] vvfat: fix field names in FAT12/FAT16 boot sector, Hervé Poussineau, 2017/05/15
- [Qemu-devel] [PATCH 09/13] vvfat: correctly create base short names for non-ASCII filenames, Hervé Poussineau, 2017/05/15
- [Qemu-devel] [PATCH 05/13] vvfat: introduce offset_to_bootsector, offset_to_fat and offset_to_root_dir, Hervé Poussineau, 2017/05/15
- [Qemu-devel] [PATCH 04/13] vvfat: rename useless enumeration values, Hervé Poussineau, 2017/05/15