3 files changed, 22 insertions, 10 deletions

diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index fbeecdc194dc..0ce143bd7d56 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -558,7 +558,7 @@ static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
         buf->f_bavail = sbi->free_clusters;
         buf->f_fsid.val[0] = (u32)id;
         buf->f_fsid.val[1] = (u32)(id >> 32);
-        buf->f_namelen = sbi->options.isvfat ? 260 : 12;
+        buf->f_namelen = sbi->options.isvfat ? FAT_LFN_LEN : 12;
 
         return 0;
 }
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
index f565f24019b5..c1ef50154868 100644
--- a/fs/fat/namei_vfat.c
+++ b/fs/fat/namei_vfat.c
@@ -502,14 +502,14 @@ xlate_to_uni(const unsigned char *name, int len, unsigned char *outname,
                 *outlen = utf8s_to_utf16s(name, len, (wchar_t *)outname);
                 if (*outlen < 0)
                         return *outlen;
-                else if (*outlen > 255)
+                else if (*outlen > FAT_LFN_LEN)
                         return -ENAMETOOLONG;
 
                 op = &outname[*outlen * sizeof(wchar_t)];
         } else {
                 if (nls) {
                         for (i = 0, ip = name, op = outname, *outlen = 0;
-                             i < len && *outlen <= 255;
+                             i < len && *outlen <= FAT_LFN_LEN;
                              *outlen += 1)
                         {
                                 if (escape && (*ip == ':')) {
@@ -549,7 +549,7 @@ xlate_to_uni(const unsigned char *name, int len, unsigned char *outname,
                                 return -ENAMETOOLONG;
                 } else {
                         for (i = 0, ip = name, op = outname, *outlen = 0;
-                             i < len && *outlen <= 255;
+                             i < len && *outlen <= FAT_LFN_LEN;
                              i++, *outlen += 1)
                         {
                                 *op++ = *ip++;
@@ -701,6 +701,15 @@ static int vfat_find(struct inode *dir, struct qstr *qname,
         return fat_search_long(dir, qname->name, len, sinfo);
 }
 
+/*
+ * (nfsd's) anonymous disconnected dentry?
+ * NOTE: !IS_ROOT() is not anonymous (I.e. d_splice_alias() did the job).
+ */
+static int vfat_d_anon_disconn(struct dentry *dentry)
+{
+        return IS_ROOT(dentry) && (dentry->d_flags & DCACHE_DISCONNECTED);
+}
+
 static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry,
                                   struct nameidata *nd)
 {
@@ -729,11 +738,11 @@ static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry,
         }
 
         alias = d_find_alias(inode);
-        if (alias && !(alias->d_flags & DCACHE_DISCONNECTED)) {
+        if (alias && !vfat_d_anon_disconn(alias)) {
                 /*
-                 * This inode has non DCACHE_DISCONNECTED dentry. This
-                 * means, the user did ->lookup() by an another name
-                 * (longname vs 8.3 alias of it) in past.
+                 * This inode has non anonymous-DCACHE_DISCONNECTED
+                 * dentry. This means, the user did ->lookup() by an
+                 * another name (longname vs 8.3 alias of it) in past.
                  *
                  * Switch to new one for reason of locality if possible.
                  */
@@ -743,7 +752,9 @@ static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry,
                 iput(inode);
                 unlock_super(sb);
                 return alias;
-        }
+        } else
+                dput(alias);
+
 out:
         unlock_super(sb);
         dentry->d_op = sb->s_root->d_op;
diff --git a/include/linux/msdos_fs.h b/include/linux/msdos_fs.h
index ce38f1caa5e1..34066e65fdeb 100644
--- a/include/linux/msdos_fs.h
+++ b/include/linux/msdos_fs.h
@@ -15,6 +15,7 @@
 #define MSDOS_DPB_BITS  4               /* log2(MSDOS_DPB) */
 #define MSDOS_DPS       (SECTOR_SIZE / sizeof(struct msdos_dir_entry))
 #define MSDOS_DPS_BITS  4               /* log2(MSDOS_DPS) */
+#define MSDOS_LONGNAME  256             /* maximum name length */
 #define CF_LE_W(v)      le16_to_cpu(v)
 #define CF_LE_L(v)      le32_to_cpu(v)
 #define CT_LE_W(v)      cpu_to_le16(v)
@@ -47,8 +48,8 @@
 #define DELETED_FLAG    0xe5    /* marks file as deleted when in name[0] */
 #define IS_FREE(n)      (!*(n) || *(n) == DELETED_FLAG)
 
+#define FAT_LFN_LEN     255     /* maximum long name length */
 #define MSDOS_NAME      11      /* maximum name length */
-#define MSDOS_LONGNAME  256     /* maximum name length */
 #define MSDOS_SLOTS     21      /* max # of slots for short and long names */
 #define MSDOS_DOT       ".          "   /* ".", padded to MSDOS_NAME chars */
 #define MSDOS_DOTDOT    "..         "   /* "..", padded to MSDOS_NAME chars */