optimize-hurd-tests

   1 ext4: optimize Hurd tests when reading/writing inodes
   2
   3 Set a in-memory superblock flag to indicate whether the file system is
   4 designed to support the Hurd.
   5
   6 Also, add a sanity check to make sure the 64-bit feature is not set
   7 for Hurd file systems, since i_file_acl_high conflicts with a
   8 Hurd-specific field.
   9
  10 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
  11 ---
  12  fs/ext4/ext4.h  |  2 ++
  13  fs/ext4/inode.c |  9 +++------
  14  fs/ext4/super.c | 10 ++++++++++
  15  3 files changed, 15 insertions(+), 6 deletions(-)
  16
  17 diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
  18 index f4f889e..e01135d 100644
  19 --- a/fs/ext4/ext4.h
  20 +++ b/fs/ext4/ext4.h
  21 @@ -1001,6 +1001,8 @@ struct ext4_inode_info {
  22  #define EXT4_MOUNT2_STD_GROUP_SIZE     0x00000002 /* We have standard group
  23                                                       size of blocksize * 8
  24                                                       blocks */
  25 +#define EXT4_MOUNT2_HURD_COMPAT                0x00000004 /* Support HURD-castrated
  26 +                                                     file systems */
  27
  28  #define clear_opt(sb, opt)             EXT4_SB(sb)->s_mount_opt &= \
  29                                                 ~EXT4_MOUNT_##opt
  30 diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
  31 index ed2c13a..b5e182a 100644
  32 --- a/fs/ext4/inode.c
  33 +++ b/fs/ext4/inode.c
  34 @@ -4168,8 +4168,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
  35         EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode);
  36         EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);
  37
  38 -       if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
  39 -           cpu_to_le32(EXT4_OS_HURD)) {
  40 +       if (likely(!test_opt2(inode->i_sb, HURD_COMPAT))) {
  41                 inode->i_version = le32_to_cpu(raw_inode->i_disk_version);
  42                 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
  43                         if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
  44 @@ -4345,8 +4344,7 @@ static int ext4_do_update_inode(handle_t *handle,
  45                 goto out_brelse;
  46         raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
  47         raw_inode->i_flags = cpu_to_le32(ei->i_flags & 0xFFFFFFFF);
  48 -       if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
  49 -           cpu_to_le32(EXT4_OS_HURD))
  50 +       if (likely(!test_opt2(inode->i_sb, HURD_COMPAT)))
  51                 raw_inode->i_file_acl_high =
  52                         cpu_to_le16(ei->i_file_acl >> 32);
  53         raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl);
  54 @@ -4391,8 +4389,7 @@ static int ext4_do_update_inode(handle_t *handle,
  55                         raw_inode->i_block[block] = ei->i_data[block];
  56         }
  57
  58 -       if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
  59 -           cpu_to_le32(EXT4_OS_HURD)) {
  60 +       if (likely(!test_opt2(inode->i_sb, HURD_COMPAT))) {
  61                 raw_inode->i_disk_version = cpu_to_le32(inode->i_version);
  62                 if (ei->i_extra_isize) {
  63                         if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
  64 diff --git a/fs/ext4/super.c b/fs/ext4/super.c
  65 index 3c9eadf..6adee9a 100644
  66 --- a/fs/ext4/super.c
  67 +++ b/fs/ext4/super.c
  68 @@ -3580,6 +3580,16 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
  69                        "feature flags set on rev 0 fs, "
  70                        "running e2fsck is recommended");
  71
  72 +       if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
  73 +               set_opt2(sb, HURD_COMPAT);
  74 +               if (EXT4_HAS_INCOMPAT_FEATURE(sb,
  75 +                                             EXT4_FEATURE_INCOMPAT_64BIT)) {
  76 +                       ext4_msg(sb, KERN_ERR,
  77 +                                "The Hurd can't support 64-bit file systems");
  78 +                       goto failed_mount;
  79 +               }
  80 +       }
  81 +
  82         if (IS_EXT2_SB(sb)) {
  83                 if (ext2_feature_set_ok(sb))
  84                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "