affs: add mount option to avoid filename truncates

Normal behavior for filenames exceeding specific filesystem limits is to
refuse operation.

AFFS standard name length being only 30 characters against 255 for usual
Linux filesystems, original implementation does filename truncate by
default with a define value AFFS_NO_TRUNCATE which can be enabled but
needs module compilation.

This patch adds 'nofilenametruncate' mount option so that user can
easily activate that feature and avoid a lot of problems (eg overwrite
files ...)

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 23 insertions, 9 deletions

diff --git a/fs/affs/namei.c b/fs/affs/namei.c
index c36cbb4537a2..6dae1ccd176d 100644
--- a/fs/affs/namei.c
+++ b/fs/affs/namei.c
@@ -60,13 +60,13 @@ affs_get_toupper(struct super_block *sb)
  * Note: the dentry argument is the parent dentry.
  */
 static inline int
-__affs_hash_dentry(struct qstr *qstr, toupper_t toupper)
+__affs_hash_dentry(struct qstr *qstr, toupper_t toupper, bool notruncate)
 {
 	const u8 *name = qstr->name;
 	unsigned long hash;
 	int i;
 
-	i = affs_check_name(qstr->name, qstr->len);
+	i = affs_check_name(qstr->name, qstr->len, notruncate);
 	if (i)
 		return i;
 
@@ -82,16 +82,22 @@ __affs_hash_dentry(struct qstr *qstr, toupper_t toupper)
 static int
 affs_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
 {
-	return __affs_hash_dentry(qstr, affs_toupper);
+	return __affs_hash_dentry(qstr, affs_toupper,
+				  affs_nofilenametruncate(dentry));
+
 }
+
 static int
 affs_intl_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
 {
-	return __affs_hash_dentry(qstr, affs_intl_toupper);
+	return __affs_hash_dentry(qstr, affs_intl_toupper,
+				  affs_nofilenametruncate(dentry));
+
 }
 
 static inline int __affs_compare_dentry(unsigned int len,
-		const char *str, const struct qstr *name, toupper_t toupper)
+		const char *str, const struct qstr *name, toupper_t toupper,
+		bool notruncate)
 {
 	const u8 *aname = str;
 	const u8 *bname = name->name;
@@ -101,7 +107,7 @@ static inline int __affs_compare_dentry(unsigned int len,
 	 * must be valid. 'name' must be validated first.
 	 */
 
-	if (affs_check_name(name->name, name->len))
+	if (affs_check_name(name->name, name->len, notruncate))
 		return 1;
 
 	/*
@@ -126,13 +132,18 @@ static int
 affs_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
 		unsigned int len, const char *str, const struct qstr *name)
 {
-	return __affs_compare_dentry(len, str, name, affs_toupper);
+
+	return __affs_compare_dentry(len, str, name, affs_toupper,
+				     affs_nofilenametruncate(parent));
 }
+
 static int
 affs_intl_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
 		unsigned int len, const char *str, const struct qstr *name)
 {
-	return __affs_compare_dentry(len, str, name, affs_intl_toupper);
+	return __affs_compare_dentry(len, str, name, affs_intl_toupper,
+				     affs_nofilenametruncate(parent));
+
 }
 
 /*
@@ -411,7 +422,10 @@ affs_rename(struct inode *old_dir, struct dentry *old_dentry,
 		 (u32)old_dir->i_ino, (int)old_dentry->d_name.len, old_dentry->d_name.name,
 		 (u32)new_dir->i_ino, (int)new_dentry->d_name.len, new_dentry->d_name.name);
 
-	retval = affs_check_name(new_dentry->d_name.name,new_dentry->d_name.len);
+	retval = affs_check_name(new_dentry->d_name.name,
+				 new_dentry->d_name.len,
+				 affs_nofilenametruncate(old_dentry));
+
 	if (retval)
 		return retval;