ldiskfs/kernel_patches/patches/ext4-export-64bit-name-hash.patch

   1 Index: linux-2.6.18-194.17.1-ext4/fs/ext4/dir.c
   2 ===================================================================
   3 --- linux-2.6.18-194.17.1-ext4.orig/fs/ext4/dir.c       2010-12-02 16:37:05.000000000 +0300
   4 +++ linux-2.6.18-194.17.1-ext4/fs/ext4/dir.c    2010-12-16 00:06:49.000000000 +0300
   5 @@ -245,19 +245,32 @@ out:
   6  /*
   7   * These functions convert from the major/minor hash to an f_pos
   8   * value.
   9 - *
  10 - * Currently we only use major hash numer.  This is unfortunate, but
  11 - * on 32-bit machines, the same VFS interface is used for lseek and
  12 - * llseek, so if we use the 64 bit offset, then the 32-bit versions of
  13 - * lseek/telldir/seekdir will blow out spectacularly, and from within
  14 - * the ext2 low-level routine, we don't know if we're being called by
  15 - * a 64-bit version of the system call or the 32-bit version of the
  16 - * system call.  Worse yet, NFSv2 only allows for a 32-bit readdir
  17 - * cookie.  Sigh.
  18 + * Whether 64-bit or 32-bit hash value is exported as file pos is
  19 + * controlled by "64bithash" mount option.
  20   */
  21 -#define hash2pos(major, minor) (major >> 1)
  22 -#define pos2maj_hash(pos)      ((pos << 1) & 0xffffffff)
  23 -#define pos2min_hash(pos)      (0)
  24 +static inline loff_t hash2pos(struct super_block *sb, __u32 major, __u32 minor)
  25 +{
  26 +       if (test_opt(sb, 64BITHASH))
  27 +               return (((__u64)(major >> 1) << 32) | (__u64)minor);
  28 +       else
  29 +               return (major >> 1);
  30 +}
  31 +
  32 +static inline __u32 pos2maj_hash(struct super_block *sb, loff_t pos)
  33 +{
  34 +       if (test_opt(sb, 64BITHASH))
  35 +               return (((pos >> 32) << 1) & 0xffffffff);
  36 +       else
  37 +               return ((pos << 1) & 0xffffffff);
  38 +}
  39 +
  40 +static inline __u32 pos2min_hash(struct super_block *sb, loff_t pos)
  41 +{
  42 +       if (test_opt(sb, 64BITHASH))
  43 +               return (pos  & 0xffffffff);
  44 +       else
  45 +               return (0);
  46 +}
  47
  48  /*
  49   * This structure holds the nodes of the red-black tree used to store
  50 @@ -318,15 +331,16 @@ static void free_rb_tree_fname(struct rb
  51  }
  52
  53
  54 -static struct dir_private_info *ext4_htree_create_dir_info(loff_t pos)
  55 +static struct dir_private_info *ext4_htree_create_dir_info(
  56 +        struct super_block *sb, loff_t pos)
  57  {
  58         struct dir_private_info *p;
  59
  60         p = kzalloc(sizeof(struct dir_private_info), GFP_KERNEL);
  61         if (!p)
  62                 return NULL;
  63 -       p->curr_hash = pos2maj_hash(pos);
  64 -       p->curr_minor_hash = pos2min_hash(pos);
  65 +       p->curr_hash = pos2maj_hash(sb, pos);
  66 +       p->curr_minor_hash = pos2min_hash(sb, pos);
  67         return p;
  68  }
  69
  70 @@ -422,7 +436,7 @@ static int call_filldir(struct file *fil
  71                        "null fname?!?\n");
  72                 return 0;
  73         }
  74 -       curr_pos = hash2pos(fname->hash, fname->minor_hash);
  75 +       curr_pos = hash2pos(sb, fname->hash, fname->minor_hash);
  76         while (fname) {
  77                 error = filldir(dirent, fname->name,
  78                                 fname->name_len, curr_pos,
  79 @@ -447,7 +461,7 @@ static int ext4_dx_readdir(struct file *
  80         int     ret;
  81
  82         if (!info) {
  83 -               info = ext4_htree_create_dir_info(filp->f_pos);
  84 +               info = ext4_htree_create_dir_info(inode->i_sb, filp->f_pos);
  85                 if (!info)
  86                         return -ENOMEM;
  87                 filp->private_data = info;
  88 @@ -461,8 +475,8 @@ static int ext4_dx_readdir(struct file *
  89                 free_rb_tree_fname(&info->root);
  90                 info->curr_node = NULL;
  91                 info->extra_fname = NULL;
  92 -               info->curr_hash = pos2maj_hash(filp->f_pos);
  93 -               info->curr_minor_hash = pos2min_hash(filp->f_pos);
  94 +               info->curr_hash = pos2maj_hash(inode->i_sb, filp->f_pos);
  95 +               info->curr_minor_hash = pos2min_hash(inode->i_sb, filp->f_pos);
  96         }
  97
  98         /*
  99 Index: linux-2.6.18-194.17.1-ext4/fs/ext4/ext4.h
 100 ===================================================================
 101 --- linux-2.6.18-194.17.1-ext4.orig/fs/ext4/ext4.h      2010-12-03 11:05:04.000000000 +0300
 102 +++ linux-2.6.18-194.17.1-ext4/fs/ext4/ext4.h   2010-12-16 00:13:32.000000000 +0300
 103 @@ -741,6 +741,7 @@ struct ext4_inode_info {
 104  #define EXT4_MOUNT_JOURNAL_CHECKSUM    0x800000 /* Journal checksums */
 105  #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT        0x1000000 /* Journal Async Commit */
 106  #define EXT4_MOUNT_I_VERSION            0x2000000 /* i_version support */
 107 +#define EXT4_MOUNT_64BITHASH           0x4000000 /* export 64-bit name hash */
 108  #define EXT4_MOUNT_DELALLOC            0x8000000 /* Delalloc support */
 109  #define EXT4_MOUNT_DATA_ERR_ABORT      0x10000000 /* Abort on file data write */
 110  #define EXT4_MOUNT_BLOCK_VALIDITY      0x20000000 /* Block validity checking */
 111 Index: linux-2.6.18-194.17.1-ext4/fs/ext4/super.c
 112 ===================================================================
 113 --- linux-2.6.18-194.17.1-ext4.orig/fs/ext4/super.c     2010-12-02 21:10:39.000000000 +0300
 114 +++ linux-2.6.18-194.17.1-ext4/fs/ext4/super.c  2010-12-15 23:57:43.000000000 +0300
 115 @@ -1479,6 +1479,7 @@ enum {
 116         Opt_iopen, Opt_noiopen, Opt_iopen_nopriv, Opt_bigendian_extents,
 117         Opt_force_over_16tb,
 118         Opt_no_mbcache,
 119 +       Opt_64bithash,
 120  };
 121
 122  static match_table_t tokens = {
 123 @@ -1552,6 +1553,7 @@ static match_table_t tokens = {
 124         {Opt_bigendian_extents, "bigendian_extents"},
 125         {Opt_force_over_16tb, "force_over_16tb"},
 126         {Opt_no_mbcache, "no_mbcache"},
 127 +       {Opt_64bithash, "64bithash"},
 128         {Opt_err, NULL},
 129  };
 130
 131 @@ -2004,6 +2006,9 @@ set_qf_format:
 132                 case Opt_no_mbcache:
 133                         set_opt(sbi->s_mount_opt, NO_MBCACHE);
 134                         break;
 135 +               case Opt_64bithash:
 136 +                       set_opt(sbi->s_mount_opt, 64BITHASH);
 137 +                       break;
 138                 default:
 139                         ext4_msg(sb, KERN_ERR,
 140                                "Unrecognized mount option \"%s\" "