fat: use same logic in fat_search_long() and __fat_readdir()

This uses uses stack for shortname, and uses __getname() for longname in
fat_search_long() and __fat_readdir().  By this, it removes unneeded
__getname() for shortname.

Signed-off-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>

1 files changed, 26 insertions, 16 deletions

diff --git a/fs/fat/dir.c b/fs/fat/dir.c
index a4410740627f..96a1cad30da4 100644
--- a/fs/fat/dir.c
+++ b/fs/fat/dir.c
@@ -325,6 +325,19 @@ parse_long:
 }
 
 /*
+ * Maximum buffer size of short name.
+ * [(MSDOS_NAME + '.') * max one char + nul]
+ * For msdos style, ['.' (hidden) + MSDOS_NAME + '.' + nul]
+ */
+#define FAT_MAX_SHORT_SIZE      ((MSDOS_NAME + 1) * NLS_MAX_CHARSET_SIZE + 1)
+/*
+ * Maximum buffer size of unicode chars from slots.
+ * [(max longname slots * 13 (size in a slot) + nul) * sizeof(wchar_t)]
+ */
+#define FAT_MAX_UNI_CHARS       ((MSDOS_SLOTS - 1) * 13 + 1)
+#define FAT_MAX_UNI_SIZE        (FAT_MAX_UNI_CHARS * sizeof(wchar_t))
+
+/*
  * Return values: negative -> error, 0 -> not found, positive -> found,
  * value is the total amount of slots, including the shortname entry.
  */
@@ -340,15 +353,11 @@ int fat_search_long(struct inode *inode, const unsigned char *name,
         wchar_t bufuname[14];
         wchar_t *unicode = NULL;
         unsigned char work[MSDOS_NAME];
-        unsigned char *bufname = NULL;
+        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;
 
-        bufname = __getname();
-        if (!bufname)
-                return -ENOMEM;
-
         err = -ENOENT;
         while (1) {
                 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
@@ -414,14 +423,17 @@ parse_record:
 
                 /* Compare shortname */
                 bufuname[last_u] = 0x0000;
-                len = fat_uni_to_x8(sbi, bufuname, bufname, PATH_MAX);
+                len = fat_uni_to_x8(sbi, bufuname, bufname, sizeof(bufname));
                 if (fat_name_match(sbi, name, name_len, bufname, len))
                         goto found;
 
                 if (nr_slots) {
+                        void *longname = unicode + FAT_MAX_UNI_CHARS;
+                        int size = PATH_MAX - FAT_MAX_UNI_SIZE;
+
                         /* Compare longname */
-                        len = fat_uni_to_x8(sbi, unicode, bufname, PATH_MAX);
-                        if (fat_name_match(sbi, name, name_len, bufname, len))
+                        len = fat_uni_to_x8(sbi, unicode, longname, size);
+                        if (fat_name_match(sbi, name, name_len, longname, len))
                                 goto found;
                 }
         }
@@ -435,8 +447,6 @@ found:
         sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
         err = 0;
 end_of_dir:
-        if (bufname)
-                __putname(bufname);
         if (unicode)
                 __putname(unicode);
 
@@ -466,7 +476,8 @@ static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent,
         unsigned char nr_slots;
         wchar_t bufuname[14];
         wchar_t *unicode = NULL;
-        unsigned char c, work[MSDOS_NAME], bufname[56], *ptname = bufname;
+        unsigned char c, work[MSDOS_NAME];
+        unsigned char bufname[FAT_MAX_SHORT_SIZE], *ptname = bufname;
         unsigned short opt_shortname = sbi->options.shortname;
         int isvfat = sbi->options.isvfat;
         int nocase = sbi->options.nocase;
@@ -620,11 +631,10 @@ parse_record:
         fill_name = bufname;
         fill_len = i;
         if (!short_only && nr_slots) {
-                /* convert the unicode long name. 261 is maximum size
-                 * of unicode buffer. (13 * slots + nul) */
-                void *longname = unicode + 261;
-                int buf_size = PATH_MAX - (261 * sizeof(unicode[0]));
-                int long_len = fat_uni_to_x8(sbi, unicode, longname, buf_size);
+                void *longname = unicode + FAT_MAX_UNI_CHARS;
+                int long_len, size = PATH_MAX - FAT_MAX_UNI_SIZE;
+
+                long_len = fat_uni_to_x8(sbi, unicode, longname, size);
 
                 if (!both) {
                         fill_name = longname;