Eric Lee / smarc-ti-linux-kernel

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Commit 02323db17e3a73dd335690b7b1a2392912b05513

Authored by Jeff Layton
Committed by Steve French
1 parent 4b660a7f5c
Exists in ti-lsk-linux-4.1.y and in 10 other branches dlt-processor-sdk-linux-03.00.00.04, processor-sdk-linux-02.00.01, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04

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 <copet_eric@emc.com>
Reported-by: <per-ola@sadata.se>
Signed-off-by: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: Steve French <smfrench@gmail.com>

Showing 1 changed file with 13 additions and 5 deletions Side-by-side Diff

... ... @@ -22,20 +22,28 @@
22 22 #ifndef _CIFSFS_H
23 23 #define _CIFSFS_H
24 24  
  25 +#include <linux/hash.h>
  26 +
25 27 #define ROOT_I 2
26 28  
27 29 /*
28 30 * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
29   - * so that it will fit.
  31 + * so that it will fit. We use hash_64 to convert the value to 31 bits, and
  32 + * then add 1, to ensure that we don't end up with a 0 as the value.
30 33 */
  34 +#if BITS_PER_LONG == 64
31 35 static inline ino_t
32 36 cifs_uniqueid_to_ino_t(u64 fileid)
33 37 {
34   - ino_t ino = (ino_t) fileid;
35   - if (sizeof(ino_t) < sizeof(u64))
36   - ino ^= fileid >> (sizeof(u64)-sizeof(ino_t)) * 8;
37   - return ino;
  38 + return (ino_t)fileid;
38 39 }
  40 +#else
  41 +static inline ino_t
  42 +cifs_uniqueid_to_ino_t(u64 fileid)
  43 +{
  44 + return (ino_t)hash_64(fileid, (sizeof(ino_t) * 8) - 1) + 1;
  45 +}
  46 +#endif
39 47  
40 48 extern struct file_system_type cifs_fs_type;
41 49 extern const struct address_space_operations cifs_addr_ops;