From 02323db17e3a73dd335690b7b1a2392912b05513 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 2 May 2014 13:50:02 -0400 Subject: cifs: fix cifs_uniqueid_to_ino_t not to ever return 0 Currently, when the top and bottom 32-bit words are equivalent and the host is a 32-bit arch, cifs_uniqueid_to_ino_t returns 0 as the ino_t value. All we're doing to hash the value down to 32 bits is xor'ing the top and bottom 32-bit words and that obviously results in 0 if they are equivalent. The kernel doesn't really care if it returns this value, but some userland apps (like "ls") will ignore dirents that have a zero d_ino value. Change this function to use hash_64 to convert this value to a 31 bit value and then add 1 to ensure that it doesn't ever return 0. Also, there's no need to check the sizeof(ino_t) at runtime so create two different cifs_uniqueid_to_ino_t functions based on whether BITS_PER_LONG is 64 for not. This should fix: https://bugzilla.kernel.org/show_bug.cgi?id=19282 Reported-by: Eric Reported-by: Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/cifsfs.h | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) (limited to 'fs/cifs') diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h index 26a754f49ba..89eab9a55f1 100644 --- a/fs/cifs/cifsfs.h +++ b/fs/cifs/cifsfs.h @@ -22,20 +22,28 @@ #ifndef _CIFSFS_H #define _CIFSFS_H +#include + #define ROOT_I 2 /* * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down - * so that it will fit. + * so that it will fit. We use hash_64 to convert the value to 31 bits, and + * then add 1, to ensure that we don't end up with a 0 as the value. */ +#if BITS_PER_LONG == 64 static inline ino_t cifs_uniqueid_to_ino_t(u64 fileid) { - ino_t ino = (ino_t) fileid; - if (sizeof(ino_t) < sizeof(u64)) - ino ^= fileid >> (sizeof(u64)-sizeof(ino_t)) * 8; - return ino; + return (ino_t)fileid; } +#else +static inline ino_t +cifs_uniqueid_to_ino_t(u64 fileid) +{ + return (ino_t)hash_64(fileid, (sizeof(ino_t) * 8) - 1) + 1; +} +#endif extern struct file_system_type cifs_fs_type; extern const struct address_space_operations cifs_addr_ops; -- cgit v1.2.3-70-g09d2