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Message-Id: <1340993528-12111-1-git-send-email-steve@digidescorp.com>
Date: Fri, 29 Jun 2012 13:12:08 -0500
From: "Steven J. Magnani" <steve@...idescorp.com>
To: OGAWA Hirofumi <hirofumi@...l.parknet.co.jp>
Cc: linux-kernel@...r.kernel.org,
"Steven J. Magnani" <steve@...idescorp.com>
Subject: [PATCH] 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@...idescorp.com>
---
diff -uprN linux-3.5-rc4/fs/fat/dir.c new/fs/fat/dir.c
--- linux-3.5-rc4/fs/fat/dir.c 2012-06-29 11:20:12.766348728 -0500
+++ new/fs/fat/dir.c 2012-06-29 13:08:53.020677428 -0500
@@ -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(int allowed, unsigned char c)
+{
+ return (allowed && (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 +338,106 @@ parse_long:
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);
+ struct nls_table *nls_disk = sbi->nls_disk;
+ unsigned short opt_shortname = sbi->options.shortname;
+ int nocase = sbi->options.nocase;
+ 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 (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) {
+ ptname[i++] = fat_tolower(!nocase, c);
+ if (c != ' ') {
+ name_len = i;
+ uni_len = j;
+ }
+ } else {
+ uni_len = j;
+ for (chi = 0; chi < chl && i < 8; chi++) {
+ ptname[i] = work[i];
+ i++;
+ name_len = i;
+ }
+ }
+ }
+
+ i = name_len;
+ j = uni_len;
+ fat_short2uni(nls_disk, ".", 1, &uni_name[j++]);
+ ptname[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++;
+ ptname[i++] = fat_tolower(!nocase, c);
+ if (c != ' ') {
+ name_len = i;
+ uni_len = j;
+ }
+ } else {
+ uni_len = j;
+ for (chi = 0; chi < chl && k < MSDOS_NAME; chi++) {
+ ptname[i++] = work[k++];
+ 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 +449,11 @@ int fat_search_long(struct inode *inode,
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 +481,16 @@ parse_record:
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 +539,15 @@ static int __fat_readdir(struct inode *i
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 +621,10 @@ parse_record:
}
}
- 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 +632,12 @@ parse_record:
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:
--
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