fat: refactor shortname parsing

Nearly identical shortname parsing is performed in fat_search_long() and
__fat_readdir().  Extract this code into a function that may be called by
both.

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Steven J. Magnani 2012-07-30 14:42:16 -07:00 committed by Linus Torvalds
parent a943ed71c9
commit deb8274a0c

View file

@ -35,6 +35,11 @@
#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)
@ -333,6 +338,124 @@ static int fat_parse_long(struct inode *dir, loff_t *pos,
return 0;
}
/**
* fat_parse_short - Parse MS-DOS (short) directory entry.
* @sb: superblock
* @de: directory entry to parse
* @name: FAT_MAX_SHORT_SIZE array in which to place extracted name
* @dot_hidden: Nonzero == prepend '.' to names with ATTR_HIDDEN
*
* Returns the number of characters extracted into 'name'.
*/
static int fat_parse_short(struct super_block *sb,
const struct msdos_dir_entry *de,
unsigned char *name, int dot_hidden)
{
const struct msdos_sb_info *sbi = MSDOS_SB(sb);
int isvfat = sbi->options.isvfat;
int nocase = sbi->options.nocase;
unsigned short opt_shortname = sbi->options.shortname;
struct nls_table *nls_disk = sbi->nls_disk;
wchar_t uni_name[14];
unsigned char c, work[MSDOS_NAME];
unsigned char *ptname = name;
int chi, chl, i, j, k;
int dotoffset = 0;
int name_len = 0, uni_len = 0;
if (!isvfat && dot_hidden && (de->attr & ATTR_HIDDEN)) {
*ptname++ = '.';
dotoffset = 1;
}
memcpy(work, de->name, sizeof(work));
/* see namei.c, msdos_format_name */
if (work[0] == 0x05)
work[0] = 0xE5;
/* Filename */
for (i = 0, j = 0; i < 8;) {
c = work[i];
if (!c)
break;
chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
&uni_name[j++], opt_shortname,
de->lcase & CASE_LOWER_BASE);
if (chl <= 1) {
if (!isvfat)
ptname[i] = nocase ? c : fat_tolower(c);
i++;
if (c != ' ') {
name_len = i;
uni_len = j;
}
} else {
uni_len = j;
if (isvfat)
i += min(chl, 8-i);
else {
for (chi = 0; chi < chl && i < 8; chi++, i++)
ptname[i] = work[i];
}
if (chl)
name_len = i;
}
}
i = name_len;
j = uni_len;
fat_short2uni(nls_disk, ".", 1, &uni_name[j++]);
if (!isvfat)
ptname[i] = '.';
i++;
/* Extension */
for (k = 8; k < MSDOS_NAME;) {
c = work[k];
if (!c)
break;
chl = fat_shortname2uni(nls_disk, &work[k], MSDOS_NAME - k,
&uni_name[j++], opt_shortname,
de->lcase & CASE_LOWER_EXT);
if (chl <= 1) {
k++;
if (!isvfat)
ptname[i] = nocase ? c : fat_tolower(c);
i++;
if (c != ' ') {
name_len = i;
uni_len = j;
}
} else {
uni_len = j;
if (isvfat) {
int offset = min(chl, MSDOS_NAME-k);
k += offset;
i += offset;
} else {
for (chi = 0; chi < chl && k < MSDOS_NAME;
chi++, i++, k++) {
ptname[i] = work[k];
}
}
if (chl)
name_len = i;
}
}
if (name_len > 0) {
name_len += dotoffset;
if (sbi->options.isvfat) {
uni_name[uni_len] = 0x0000;
name_len = fat_uni_to_x8(sb, uni_name, name,
FAT_MAX_SHORT_SIZE);
}
}
return name_len;
}
/*
* Return values: negative -> error, 0 -> not found, positive -> found,
* value is the total amount of slots, including the shortname entry.
@ -344,15 +467,11 @@ int fat_search_long(struct inode *inode, const unsigned char *name,
struct msdos_sb_info *sbi = MSDOS_SB(sb);
struct buffer_head *bh = NULL;
struct msdos_dir_entry *de;
struct nls_table *nls_disk = sbi->nls_disk;
unsigned char nr_slots;
wchar_t bufuname[14];
wchar_t *unicode = NULL;
unsigned char work[MSDOS_NAME];
unsigned char bufname[FAT_MAX_SHORT_SIZE];
unsigned short opt_shortname = sbi->options.shortname;
loff_t cpos = 0;
int chl, i, j, last_u, err, len;
int err, len;
err = -ENOENT;
while (1) {
@ -380,47 +499,16 @@ int fat_search_long(struct inode *inode, const unsigned char *name,
goto end_of_dir;
}
memcpy(work, de->name, sizeof(de->name));
/* see namei.c, msdos_format_name */
if (work[0] == 0x05)
work[0] = 0xE5;
for (i = 0, j = 0, last_u = 0; i < 8;) {
if (!work[i])
break;
chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
&bufuname[j++], opt_shortname,
de->lcase & CASE_LOWER_BASE);
if (chl <= 1) {
if (work[i] != ' ')
last_u = j;
} else {
last_u = j;
}
i += chl;
}
j = last_u;
fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
for (i = 8; i < MSDOS_NAME;) {
if (!work[i])
break;
chl = fat_shortname2uni(nls_disk, &work[i],
MSDOS_NAME - i,
&bufuname[j++], opt_shortname,
de->lcase & CASE_LOWER_EXT);
if (chl <= 1) {
if (work[i] != ' ')
last_u = j;
} else {
last_u = j;
}
i += chl;
}
if (!last_u)
/* Never prepend '.' to hidden files here.
* That is done only for msdos mounts (and only when
* 'dotsOK=yes'); if we are executing here, it is in the
* context of a vfat mount.
*/
len = fat_parse_short(sb, de, bufname, 0);
if (len == 0)
continue;
/* Compare shortname */
bufuname[last_u] = 0x0000;
len = fat_uni_to_x8(sb, bufuname, bufname, sizeof(bufname));
if (fat_name_match(sbi, name, name_len, bufname, len))
goto found;
@ -469,20 +557,15 @@ static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent,
struct msdos_sb_info *sbi = MSDOS_SB(sb);
struct buffer_head *bh;
struct msdos_dir_entry *de;
struct nls_table *nls_disk = sbi->nls_disk;
unsigned char nr_slots;
wchar_t bufuname[14];
wchar_t *unicode = NULL;
unsigned char c, work[MSDOS_NAME];
unsigned char bufname[FAT_MAX_SHORT_SIZE], *ptname = bufname;
unsigned short opt_shortname = sbi->options.shortname;
unsigned char bufname[FAT_MAX_SHORT_SIZE];
int isvfat = sbi->options.isvfat;
int nocase = sbi->options.nocase;
const char *fill_name = NULL;
unsigned long inum;
unsigned long lpos, dummy, *furrfu = &lpos;
loff_t cpos;
int chi, chl, i, i2, j, last, last_u, dotoffset = 0, fill_len = 0;
int short_len = 0, fill_len = 0;
int ret = 0;
lock_super(sb);
@ -556,74 +639,10 @@ static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent,
}
}
if (sbi->options.dotsOK) {
ptname = bufname;
dotoffset = 0;
if (de->attr & ATTR_HIDDEN) {
*ptname++ = '.';
dotoffset = 1;
}
}
memcpy(work, de->name, sizeof(de->name));
/* see namei.c, msdos_format_name */
if (work[0] == 0x05)
work[0] = 0xE5;
for (i = 0, j = 0, last = 0, last_u = 0; i < 8;) {
if (!(c = work[i]))
break;
chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
&bufuname[j++], opt_shortname,
de->lcase & CASE_LOWER_BASE);
if (chl <= 1) {
ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
if (c != ' ') {
last = i;
last_u = j;
}
} else {
last_u = j;
for (chi = 0; chi < chl && i < 8; chi++) {
ptname[i] = work[i];
i++; last = i;
}
}
}
i = last;
j = last_u;
fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
ptname[i++] = '.';
for (i2 = 8; i2 < MSDOS_NAME;) {
if (!(c = work[i2]))
break;
chl = fat_shortname2uni(nls_disk, &work[i2], MSDOS_NAME - i2,
&bufuname[j++], opt_shortname,
de->lcase & CASE_LOWER_EXT);
if (chl <= 1) {
i2++;
ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
if (c != ' ') {
last = i;
last_u = j;
}
} else {
last_u = j;
for (chi = 0; chi < chl && i2 < MSDOS_NAME; chi++) {
ptname[i++] = work[i2++];
last = i;
}
}
}
if (!last)
short_len = fat_parse_short(sb, de, bufname, sbi->options.dotsOK);
if (short_len == 0)
goto record_end;
i = last + dotoffset;
j = last_u;
if (isvfat) {
bufuname[j] = 0x0000;
i = fat_uni_to_x8(sb, bufuname, bufname, sizeof(bufname));
}
if (nr_slots) {
/* hack for fat_ioctl_filldir() */
struct fat_ioctl_filldir_callback *p = dirent;
@ -631,12 +650,12 @@ static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent,
p->longname = fill_name;
p->long_len = fill_len;
p->shortname = bufname;
p->short_len = i;
p->short_len = short_len;
fill_name = NULL;
fill_len = 0;
} else {
fill_name = bufname;
fill_len = i;
fill_len = short_len;
}
start_filldir: