As a result of some of Al Viro's great work, here are a few cleanups

with fixes for adfs:
 
 - factor out filename comparison, so we can be sure that adfs_compare()
   (used for namei compare) and adfs_match() (used for lookup) have the
   same behaviour.
 - factor out filename lowering (which is not the same as tolower() which
   will lower top-bit-set characters) to ensure that we have the same
   behaviour when comparing filenames as when we hash them.
 - factor out the object fixups, so we are applying all fixups to
   directory objects in the same way, independent of the disk format.
 - factor out the object name fixup (into the previously factored out
   function) to ensure that filenames are appropriately translated -
   for example, adfs allows '/' in filenames, which being the Unix path
   separator, need to be translated to a different character, which is
   normally '.' (DOS 8.3 filenames represent the . as a / on adfs, so
   this is the expected reverse translation.)
 - remove filename truncation; Al asked about this and apparently the
   decision is to remove it.  In any case, adfs's truncation was buggy,
   so this rids us of that bug by removing the truncation feature.
 - we now have only one location which adds the "filetype" suffix to the
   filename, so there's no point that code being out of line.
 - since we translate '/' into '.', an adfs filename of "/" or "//" would
   end up being translated to "." and ".." which have special meanings.
   In this case, change the first character to "^" to avoid these special
   directory names being abused.
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Merge tag 'for-rc-adfs' of git://git.armlinux.org.uk/~rmk/linux-arm

Pull ADFS cleanups/fixes from Russell King:
 "As a result of some of Al Viro's great work, here are a few cleanups
  with fixes for adfs:

   - factor out filename comparison, so we can be sure that
     adfs_compare() (used for namei compare) and adfs_match() (used for
     lookup) have the same behaviour.

   - factor out filename lowering (which is not the same as tolower()
     which will lower top-bit-set characters) to ensure that we have the
     same behaviour when comparing filenames as when we hash them.

   - factor out the object fixups, so we are applying all fixups to
     directory objects in the same way, independent of the disk format.

   - factor out the object name fixup (into the previously factored out
     function) to ensure that filenames are appropriately translated -
     for example, adfs allows '/' in filenames, which being the Unix
     path separator, need to be translated to a different character,
     which is normally '.' (DOS 8.3 filenames represent the . as a / on
     adfs, so this is the expected reverse translation.)

   - remove filename truncation; Al asked about this and apparently the
     decision is to remove it. In any case, adfs's truncation was buggy,
     so this rids us of that bug by removing the truncation feature.

   - we now have only one location which adds the "filetype" suffix to
     the filename, so there's no point that code being out of line.

   - since we translate '/' into '.', an adfs filename of "/" or "//"
     would end up being translated to "." and ".." which have special
     meanings. In this case, change the first character to "^" to avoid
     these special directory names being abused"

* tag 'for-rc-adfs' of git://git.armlinux.org.uk/~rmk/linux-arm:
  fs/adfs: fix filename fixup handling for "/" and "//" names
  fs/adfs: move append_filetype_suffix() into adfs_object_fixup()
  fs/adfs: remove truncated filename hashing
  fs/adfs: factor out filename fixup
  fs/adfs: factor out object fixups
  fs/adfs: factor out filename case lowering
  fs/adfs: factor out filename comparison

fs/adfs/adfs.h

@@ -113,19 +113,6 @@ struct object_info {
 	__u16		filetype;
 };
 
-/* RISC OS 12-bit filetype converts to ,xyz hex filename suffix */
-static inline int append_filetype_suffix(char *buf, __u16 filetype)
-{
-	if (filetype == 0xffff)	/* no explicit 12-bit file type was set */
-		return 0;
-
-	*buf++ = ',';
-	*buf++ = hex_asc_lo(filetype >> 8);
-	*buf++ = hex_asc_lo(filetype >> 4);
-	*buf++ = hex_asc_lo(filetype >> 0);
-	return 4;
-}
-
 struct adfs_dir_ops {
 	int	(*read)(struct super_block *sb, unsigned int id, unsigned int sz, struct adfs_dir *dir);
 	int	(*setpos)(struct adfs_dir *dir, unsigned int fpos);
@@ -172,6 +159,7 @@ extern const struct dentry_operations adfs_dentry_operations;
 extern const struct adfs_dir_ops adfs_f_dir_ops;
 extern const struct adfs_dir_ops adfs_fplus_dir_ops;
 
+void adfs_object_fixup(struct adfs_dir *dir, struct object_info *obj);
 extern int adfs_dir_update(struct super_block *sb, struct object_info *obj,
 			   int wait);
 

fs/adfs/dir.c

@@ -16,6 +16,50 @@
  */
 static DEFINE_RWLOCK(adfs_dir_lock);
 
+void adfs_object_fixup(struct adfs_dir *dir, struct object_info *obj)
+{
+	unsigned int dots, i;
+
+	/*
+	 * RISC OS allows the use of '/' in directory entry names, so we need
+	 * to fix these up.  '/' is typically used for FAT compatibility to
+	 * represent '.', so do the same conversion here.  In any case, '.'
+	 * will never be in a RISC OS name since it is used as the pathname
+	 * separator.  Handle the case where we may generate a '.' or '..'
+	 * name, replacing the first character with '^' (the RISC OS "parent
+	 * directory" character.)
+	 */
+	for (i = dots = 0; i < obj->name_len; i++)
+		if (obj->name[i] == '/') {
+			obj->name[i] = '.';
+			dots++;
+		}
+
+	if (obj->name_len <= 2 && dots == obj->name_len)
+		obj->name[0] = '^';
+
+	obj->filetype = -1;
+
+	/*
+	 * object is a file and is filetyped and timestamped?
+	 * RISC OS 12-bit filetype is stored in load_address[19:8]
+	 */
+	if ((0 == (obj->attr & ADFS_NDA_DIRECTORY)) &&
+	    (0xfff00000 == (0xfff00000 & obj->loadaddr))) {
+		obj->filetype = (__u16) ((0x000fff00 & obj->loadaddr) >> 8);
+
+		/* optionally append the ,xyz hex filetype suffix */
+		if (ADFS_SB(dir->sb)->s_ftsuffix) {
+			__u16 filetype = obj->filetype;
+
+			obj->name[obj->name_len++] = ',';
+			obj->name[obj->name_len++] = hex_asc_lo(filetype >> 8);
+			obj->name[obj->name_len++] = hex_asc_lo(filetype >> 4);
+			obj->name[obj->name_len++] = hex_asc_lo(filetype >> 0);
+		}
+	}
+}
+
 static int
 adfs_readdir(struct file *file, struct dir_context *ctx)
 {
@@ -100,37 +144,36 @@ out:
 	return ret;
 }
 
-static int
+static unsigned char adfs_tolower(unsigned char c)
-adfs_match(const struct qstr *name, struct object_info *obj)
 {
-	int i;
+	if (c >= 'A' && c <= 'Z')
-
+		c += 'a' - 'A';
-	if (name->len != obj->name_len)
+	return c;
-		return 0;
-
-	for (i = 0; i < name->len; i++) {
-		char c1, c2;
-
-		c1 = name->name[i];
-		c2 = obj->name[i];
-
-		if (c1 >= 'A' && c1 <= 'Z')
-			c1 += 'a' - 'A';
-		if (c2 >= 'A' && c2 <= 'Z')
-			c2 += 'a' - 'A';
-
-		if (c1 != c2)
-			return 0;
-	}
-	return 1;
 }
 
-static int
+static int __adfs_compare(const unsigned char *qstr, u32 qlen,
-adfs_dir_lookup_byname(struct inode *inode, const struct qstr *name, struct object_info *obj)
+			  const char *str, u32 len)
+{
+	u32 i;
+
+	if (qlen != len)
+		return 1;
+
+	for (i = 0; i < qlen; i++)
+		if (adfs_tolower(qstr[i]) != adfs_tolower(str[i]))
+			return 1;
+
+	return 0;
+}
+
+static int adfs_dir_lookup_byname(struct inode *inode, const struct qstr *qstr,
+				  struct object_info *obj)
 {
 	struct super_block *sb = inode->i_sb;
 	const struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
+	const unsigned char *name;
 	struct adfs_dir dir;
+	u32 name_len;
 	int ret;
 
 	ret = ops->read(sb, inode->i_ino, inode->i_size, &dir);
@@ -153,8 +196,10 @@ adfs_dir_lookup_byname(struct inode *inode, const struct qstr *name, struct obje
 		goto unlock_out;
 
 	ret = -ENOENT;
+	name = qstr->name;
+	name_len = qstr->len;
 	while (ops->getnext(&dir, obj) == 0) {
-		if (adfs_match(name, obj)) {
+		if (!__adfs_compare(name, name_len, obj->name, obj->name_len)) {
 			ret = 0;
 			break;
 		}
@@ -179,30 +224,18 @@ const struct file_operations adfs_dir_operations = {
 static int
 adfs_hash(const struct dentry *parent, struct qstr *qstr)
 {
-	const unsigned int name_len = ADFS_SB(parent->d_sb)->s_namelen;
 	const unsigned char *name;
 	unsigned long hash;
-	int i;
+	u32 len;
 
-	if (qstr->len < name_len)
+	if (qstr->len > ADFS_SB(parent->d_sb)->s_namelen)
-		return 0;
+		return -ENAMETOOLONG;
 
-	/*
+	len = qstr->len;
-	 * Truncate the name in place, avoids
-	 * having to define a compare function.
-	 */
-	qstr->len = i = name_len;
 	name = qstr->name;
 	hash = init_name_hash(parent);
-	while (i--) {
+	while (len--)
-		char c;
+		hash = partial_name_hash(adfs_tolower(*name++), hash);
-
-		c = *name++;
-		if (c >= 'A' && c <= 'Z')
-			c += 'a' - 'A';
-
-		hash = partial_name_hash(c, hash);
-	}
 	qstr->hash = end_name_hash(hash);
 
 	return 0;
@@ -212,30 +245,10 @@ adfs_hash(const struct dentry *parent, struct qstr *qstr)
  * Compare two names, taking note of the name length
  * requirements of the underlying filesystem.
  */
-static int
+static int adfs_compare(const struct dentry *dentry, unsigned int len,
-adfs_compare(const struct dentry *dentry,
+			const char *str, const struct qstr *qstr)
-		unsigned int len, const char *str, const struct qstr *name)
 {
-	int i;
+	return __adfs_compare(qstr->name, qstr->len, str, len);
-
-	if (len != name->len)
-		return 1;
-
-	for (i = 0; i < name->len; i++) {
-		char a, b;
-
-		a = str[i];
-		b = name->name[i];
-
-		if (a >= 'A' && a <= 'Z')
-			a += 'a' - 'A';
-		if (b >= 'A' && b <= 'Z')
-			b += 'a' - 'A';
-
-		if (a != b)
-			return 1;
-	}
-	return 0;
 }
 
 const struct dentry_operations adfs_dentry_operations = {

fs/adfs/dir_f.c

@@ -47,21 +47,6 @@ static inline void adfs_writeval(unsigned char *p, int len, unsigned int val)
 	}
 }
 
-static inline int adfs_readname(char *buf, char *ptr, int maxlen)
-{
-	char *old_buf = buf;
-
-	while ((unsigned char)*ptr >= ' ' && maxlen--) {
-		if (*ptr == '/')
-			*buf++ = '.';
-		else
-			*buf++ = *ptr;
-		ptr++;
-	}
-
-	return buf - old_buf;
-}
-
 #define ror13(v) ((v >> 13) | (v << 19))
 
 #define dir_u8(idx)				\
@@ -216,29 +201,23 @@ static inline void
 adfs_dir2obj(struct adfs_dir *dir, struct object_info *obj,
 	struct adfs_direntry *de)
 {
-	obj->name_len =	adfs_readname(obj->name, de->dirobname, ADFS_F_NAME_LEN);
+	unsigned int name_len;
+
+	for (name_len = 0; name_len < ADFS_F_NAME_LEN; name_len++) {
+		if (de->dirobname[name_len] < ' ')
+			break;
+
+		obj->name[name_len] = de->dirobname[name_len];
+	}
+
+	obj->name_len =	name_len;
 	obj->file_id  = adfs_readval(de->dirinddiscadd, 3);
 	obj->loadaddr = adfs_readval(de->dirload, 4);
 	obj->execaddr = adfs_readval(de->direxec, 4);
 	obj->size     = adfs_readval(de->dirlen,  4);
 	obj->attr     = de->newdiratts;
-	obj->filetype = -1;
 
-	/*
+	adfs_object_fixup(dir, obj);
-	 * object is a file and is filetyped and timestamped?
-	 * RISC OS 12-bit filetype is stored in load_address[19:8]
-	 */
-	if ((0 == (obj->attr & ADFS_NDA_DIRECTORY)) &&
-		(0xfff00000 == (0xfff00000 & obj->loadaddr))) {
-		obj->filetype = (__u16) ((0x000fff00 & obj->loadaddr) >> 8);
-
-		/* optionally append the ,xyz hex filetype suffix */
-		if (ADFS_SB(dir->sb)->s_ftsuffix)
-			obj->name_len +=
-				append_filetype_suffix(
-					&obj->name[obj->name_len],
-					obj->filetype);
-	}
 }
 
 /*

fs/adfs/dir_fplus.c

@@ -169,7 +169,7 @@ adfs_fplus_getnext(struct adfs_dir *dir, struct object_info *obj)
 		(struct adfs_bigdirheader *) dir->bh_fplus[0]->b_data;
 	struct adfs_bigdirentry bde;
 	unsigned int offset;
-	int i, ret = -ENOENT;
+	int ret = -ENOENT;
 
 	if (dir->pos >= le32_to_cpu(h->bigdirentries))
 		goto out;
@@ -193,27 +193,7 @@ adfs_fplus_getnext(struct adfs_dir *dir, struct object_info *obj)
 	offset += le32_to_cpu(bde.bigdirobnameptr);
 
 	dir_memcpy(dir, offset, obj->name, obj->name_len);
-	for (i = 0; i < obj->name_len; i++)
+	adfs_object_fixup(dir, obj);
-		if (obj->name[i] == '/')
-			obj->name[i] = '.';
-
-	obj->filetype = -1;
-
-	/*
-	 * object is a file and is filetyped and timestamped?
-	 * RISC OS 12-bit filetype is stored in load_address[19:8]
-	 */
-	if ((0 == (obj->attr & ADFS_NDA_DIRECTORY)) &&
-		(0xfff00000 == (0xfff00000 & obj->loadaddr))) {
-		obj->filetype = (__u16) ((0x000fff00 & obj->loadaddr) >> 8);
-
-		/* optionally append the ,xyz hex filetype suffix */
-		if (ADFS_SB(dir->sb)->s_ftsuffix)
-			obj->name_len +=
-				append_filetype_suffix(
-					&obj->name[obj->name_len],
-					obj->filetype);
-	}
 
 	dir->pos += 1;
 	ret = 0;