[PATCH v2 2/4] isofs: report the Joliet name length in statfs

[Matthias Goergens <matthias.goergens@gmail.com>]

isofs_statfs() reports NAME_MAX as the longest name, but a Joliet name
can now be up to JOLIET_NAME_MAX bytes long.  glibc answers
pathconf(_PC_NAME_MAX) from f_namelen, so a program sizing a buffer from
it should get room for every name readdir returns.  vfat has reported
255 times NLS_MAX_CHARSET_SIZE, 1530, since commit f68e542f3478 ("fat:
Fix statfs->f_namelen"), which followed a report of readdir_r()
overflowing a buffer sized that way, and exfat reports the same.
Windows reports a maximum component length of 110 for CDFS.

Report JOLIET_NAME_MAX on Joliet mounts.  Rock Ridge and plain ISO 9660
mounts keep NAME_MAX.

Signed-off-by: Matthias Goergens <matthias.goergens@gmail.com>
---
 fs/isofs/inode.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c
index b766b5c9c593..23c51eaf8356 100644
--- a/fs/isofs/inode.c
+++ b/fs/isofs/inode.c
@@ -1012,7 +1012,8 @@ static int isofs_statfs (struct dentry *dentry, struct kstatfs *buf)
 	buf->f_files = ISOFS_SB(sb)->s_ninodes;
 	buf->f_ffree = 0;
 	buf->f_fsid = u64_to_fsid(id);
-	buf->f_namelen = NAME_MAX;
+	buf->f_namelen = ISOFS_SB(sb)->s_joliet_level ?
+			 JOLIET_NAME_MAX : NAME_MAX;
 	return 0;
 }
 
-- 
2.55.0