LDLINUX:vfat: Oh, NO, I did fix the above bug in a wrong way!

I shouldn't count on the 'dname' parameter, we should ZERO the
'long_name' buffer at every time we met a new long name entry,
and that's the right way to fix the bug.

And we shouldn't count the 'id == 0' to check if we have a long
name matched first or not. Say we have one entry of a long name
entry, it will always be 'id == 0' even it doesn't matches. So,
add a new flag variable to do this.

Signed-off-by: Liu Aleaxander <Aleaxander@gmail.com>

diff --git a/core/fs/fat/fat.c b/core/fs/fat/fat.c
index 9cb9f99..7ed714b 100644 (file)
--- a/core/fs/fat/fat.c
+++ b/core/fs/fat/fat.c
@@ -411,6 +411,7 @@ static struct inode *vfat_find_entry(char *dname, struct inode *dir)
     int slots;
     int entries;
     int checksum;
+    int long_match = 0;
     
     slots = (strlen(dname) + 12) / 13 ;
     slots |= 0x40;
@@ -438,6 +439,9 @@ static struct inode *vfat_find_entry(char *dname, struct inode *dir)
                    /* get the initial checksum value */
                    vfat_csum = long_de->checksum;
                    id &= 0x3f;
+
+                   /* ZERO the long_name buffer */
+                   memset(long_name, 0, sizeof long_name);
                } else {
                    if (long_de->checksum != vfat_csum)
                        goto not_match;
@@ -448,8 +452,7 @@ static struct inode *vfat_find_entry(char *dname, struct inode *dir)
                /* got the long entry name */
                long_entry_name(long_de);
                memcpy(long_name + id * 13, entry_name, 13);
-               long_name[strlen(dname)] = '\0';
-               
+                               
                /* 
                 * If we got the last entry, check it.
                 * Or, go on with the next entry.
@@ -457,6 +460,7 @@ static struct inode *vfat_find_entry(char *dname, struct inode *dir)
                if (id == 0) {
                    if (strcmp(long_name, dname))
                        goto not_match;
+                   long_match = 1;
                }
                
                de++;
@@ -468,12 +472,14 @@ static struct inode *vfat_find_entry(char *dname, struct inode *dir)
                if (de->attr & 0x08) /* ignore volume labels */
                    goto not_match;
                
-               /* If we have a long name match, then vfat_next must be 0 */
-               if (vfat_next == 0) {
+               if (long_match == 1) {
                    /* 
                     * We already have a VFAT long name match. However, the 
                     * match is only valid if the checksum matches.
+                    *
+                    * Well, let's trun the long_match flag off first.
                     */
+                    long_match = 0;
                    checksum = get_checksum(de->name);
                    if (checksum == vfat_csum)
                        goto found;  /* Got it */