ldiskfs/kernel_patches/patches/sles12sp2/ext4-disable-mb-cache.patch

   1 mbcache provides absolutely no value for Lustre xattrs (because
   2 they are unique and cannot be shared between files) and as we can
   3 see it has a noticable overhead in some cases. In the past there
   4 was a CONFIG_MBCACHE option that would allow it to be disabled,
   5 but this was removed in newer kernels, so we will need to patch
   6 ldiskfs to fix this.
   7
   8 Index: linux-3.10.0-123.13.2.el7.x86_64/fs/ext4/ext4.h
   9 ===================================================================
  10 --- linux-3.10.0-123.13.2.el7.x86_64.orig/fs/ext4/ext4.h
  11 +++ linux-3.10.0-123.13.2.el7.x86_64/fs/ext4/ext4.h
  12 @@ -944,6 +944,7 @@ struct ext4_inode_info {
  13  /*
  14   * Mount flags set via mount options or defaults
  15   */
  16 +#define EXT4_MOUNT_NO_MBCACHE          0x00001 /* Disable mbcache */
  17  #define EXT4_MOUNT_GRPID               0x00004 /* Create files with directory's group */
  18  #define EXT4_MOUNT_DEBUG               0x00008 /* Some debugging messages */
  19  #define EXT4_MOUNT_ERRORS_CONT         0x00010 /* Continue on errors */
  20 Index: linux-3.10.0-123.13.2.el7.x86_64/fs/ext4/super.c
  21 ===================================================================
  22 --- linux-3.10.0-123.13.2.el7.x86_64.orig/fs/ext4/super.c
  23 +++ linux-3.10.0-123.13.2.el7.x86_64/fs/ext4/super.c
  24 @@ -1157,6 +1157,7 @@ enum {
  25         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
  26         Opt_inode_readahead_blks, Opt_journal_ioprio,
  27         Opt_dioread_nolock, Opt_dioread_lock,
  28 +       Opt_no_mbcache,
  29         Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
  30         Opt_max_dir_size_kb,
  31  };
  32 @@ -1231,6 +1232,7 @@ static const match_table_t tokens = {
  33         {Opt_discard, "discard"},
  34         {Opt_nodiscard, "nodiscard"},
  35         {Opt_init_itable, "init_itable=%u"},
  36 +       {Opt_no_mbcache, "no_mbcache"},
  37         {Opt_init_itable, "init_itable"},
  38         {Opt_noinit_itable, "noinit_itable"},
  39         {Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
  40 @@ -1390,6 +1392,7 @@ static const struct mount_opts {
  41         {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
  42         {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
  43         {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
  44 +       {Opt_no_mbcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
  45         {Opt_commit, 0, MOPT_GTE0},
  46         {Opt_max_batch_time, 0, MOPT_GTE0},
  47         {Opt_min_batch_time, 0, MOPT_GTE0},
  48 Index: linux-3.10.0-123.13.2.el7.x86_64/fs/ext4/xattr.c
  49 ===================================================================
  50 --- linux-3.10.0-123.13.2.el7.x86_64.orig/fs/ext4/xattr.c
  51 +++ linux-3.10.0-123.13.2.el7.x86_64/fs/ext4/xattr.c
  52 @@ -80,7 +80,7 @@
  53  # define ea_bdebug(bh, fmt, ...)       no_printk(fmt, ##__VA_ARGS__)
  54  #endif
  55
  56 -static void ext4_xattr_cache_insert(struct mb_cache *, struct buffer_head *);
  57 +static void _ext4_xattr_cache_insert(struct mb_cache *, struct buffer_head *);
  58  static struct buffer_head *ext4_xattr_cache_find(struct inode *,
  59                                                  struct ext4_xattr_header *,
  60                                                  struct mb_cache_entry **);
  61 @@ -401,7 +401,8 @@ bad_block:
  62                 error = -EFSCORRUPTED;
  63                 goto cleanup;
  64         }
  65 -       ext4_xattr_cache_insert(ext4_mb_cache, bh);
  66 +       if (!test_opt(inode->i_sb, NO_MBCACHE))
  67 +               _ext4_xattr_cache_insert(ext4_mb_cache, bh);
  68         entry = BFIRST(bh);
  69         error = ext4_xattr_find_entry(&entry, name_index, name, bh->b_size, 1,
  70                                       inode);
  71 @@ -565,7 +566,8 @@ ext4_xattr_block_list(struct dentry *den
  72                 error = -EFSCORRUPTED;
  73                 goto cleanup;
  74         }
  75 -       ext4_xattr_cache_insert(ext4_mb_cache, bh);
  76 +       if (!test_opt(inode->i_sb, NO_MBCACHE))
  77 +               _ext4_xattr_cache_insert(ext4_mb_cache, bh);
  78         error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size);
  79
  80  cleanup:
  81 @@ -678,7 +680,9 @@ ext4_xattr_release_block(handle_t *handl
  82                  * This must happen under buffer lock for
  83                  * ext4_xattr_block_set() to reliably detect freed block
  84                  */
  85 -               mb_cache_entry_delete_block(ext4_mb_cache, hash, bh->b_blocknr);
  86 +               if (!test_opt(inode->i_sb, NO_MBCACHE))
  87 +                       mb_cache_entry_delete_block(ext4_mb_cache,
  88 +                                                   hash, bh->b_blocknr);
  89                 get_bh(bh);
  90                 unlock_buffer(bh);
  91                 ext4_free_blocks(handle, inode, bh, 0, 1,
  92 @@ -690,9 +694,10 @@ ext4_xattr_release_block(handle_t *handl
  93
  94
  95                 if (ref == EXT4_XATTR_REFCOUNT_MAX - 1) {
  96 -                       struct mb_cache_entry *ce;
  97 +                       struct mb_cache_entry *ce = NULL;
  98
  99 -                       ce = mb_cache_entry_get(ext4_mb_cache, hash,
 100 +                       if (!test_opt(inode->i_sb, NO_MBCACHE))
 101 +                               ce = mb_cache_entry_get(ext4_mb_cache, hash,
 102                                                 bh->b_blocknr);
 103                         if (ce) {
 104                                 ce->e_reusable = 1;
 105 @@ -1107,7 +1112,8 @@ ext4_xattr_block_set(handle_t *handle, s
 106                          * ext4_xattr_block_set() to reliably detect modified
 107                          * block
 108                          */
 109 -                       mb_cache_entry_delete_block(ext4_mb_cache, hash,
 110 +                       if (!test_opt(inode->i_sb, NO_MBCACHE))
 111 +                               mb_cache_entry_delete_block(ext4_mb_cache, hash,
 112                                                     bs->bh->b_blocknr);
 113                         ea_bdebug(bs->bh, "modifying in-place");
 114                         error = ext4_xattr_set_entry(i, s, handle, inode);
 115 @@ -1115,8 +1121,9 @@ ext4_xattr_block_set(handle_t *handle, s
 116                                 if (!IS_LAST_ENTRY(s->first))
 117                                         ext4_xattr_rehash(header(s->base),
 118                                                           s->here);
 119 -                               ext4_xattr_cache_insert(ext4_mb_cache,
 120 -                                       bs->bh);
 121 +                               if (!test_opt(inode->i_sb, NO_MBCACHE))
 122 +                                       _ext4_xattr_cache_insert(ext4_mb_cache,
 123 +                                                               bs->bh);
 124                         }
 125                         unlock_buffer(bs->bh);
 126                         if (error == -EFSCORRUPTED)
 127 @@ -1277,7 +1284,8 @@ getblk_failed:
 128                         memcpy(new_bh->b_data, s->base, new_bh->b_size);
 129                         set_buffer_uptodate(new_bh);
 130                         unlock_buffer(new_bh);
 131 -                       ext4_xattr_cache_insert(ext4_mb_cache, new_bh);
 132 +                       if (!test_opt(inode->i_sb, NO_MBCACHE))
 133 +                               _ext4_xattr_cache_insert(ext4_mb_cache, new_bh);
 134                         error = ext4_handle_dirty_xattr_block(handle,
 135                                                               inode, new_bh);
 136                         if (error)
 137 @@ -2068,7 +2076,7 @@ ext4_xattr_inode_array_free(struct inode
 138   * Returns 0, or a negative error number on failure.
 139   */
 140  static void
 141 -ext4_xattr_cache_insert(struct mb_cache *ext4_mb_cache, struct buffer_head *bh)
 142 +_ext4_xattr_cache_insert(struct mb_cache *ext4_mb_cache, struct buffer_head *bh)
 143  {
 144         struct ext4_xattr_header *header = BHDR(bh);
 145         __u32 hash = le32_to_cpu(header->h_hash);
 146 @@ -2140,6 +2148,8 @@ ext4_xattr_cache_find(struct inode *inod
 147         struct mb_cache_entry *ce;
 148         struct mb_cache *ext4_mb_cache = EXT4_GET_MB_CACHE(inode);
 149
 150 +       if (test_opt(inode->i_sb, NO_MBCACHE))
 151 +               return NULL;
 152         if (!header->h_hash)
 153                 return NULL;  /* never share */
 154         ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);