lustre/kernel_patches/patches/jbd2-jcberr-2.6-rhel6.patch

   1 This allows the jbd transaction commit callbacks to be registered.
   2 The ext4 jbd2 code has a different commit callback (one per transaction)
   3 that could be used to provide equivalent functionality.  This would
   4 require modifying the existing ext4 commit callback (used by mballoc
   5 when freeing data blocks) to be mutiplexed so it will store 2 different
   6 callback functions and 2 different lists of callback data.
   7
   8 Index: linux+rh+chaos/include/linux/jbd2.h
   9 ===================================================================
  10 --- linux+rh+chaos.orig/include/linux/jbd2.h
  11 +++ linux+rh+chaos/include/linux/jbd2.h
  12 @@ -415,6 +415,27 @@ struct jbd2_inode {
  13         unsigned int i_flags;
  14  };
  15
  16 +#define HAVE_JOURNAL_CALLBACK_STATUS
  17 +/**
  18 + *   struct journal_callback - Base structure for callback information.
  19 + *   @jcb_list: list information for other callbacks attached to the same handle.
  20 + *   @jcb_func: Function to call with this callback structure.
  21 + *
  22 + *   This struct is a 'seed' structure for a using with your own callback
  23 + *   structs. If you are using callbacks you must allocate one of these
  24 + *   or another struct of your own definition which has this struct
  25 + *   as it's first element and pass it to journal_callback_set().
  26 + *
  27 + *   This is used internally by jbd2 to maintain callback information.
  28 + *
  29 + *   See journal_callback_set for more information.
  30 + **/
  31 +struct journal_callback {
  32 +       struct list_head jcb_list;              /* t_jcb_lock */
  33 +       void (*jcb_func)(struct journal_callback *jcb, int error);
  34 +       /* user data goes here */
  35 +};
  36 +
  37  struct jbd2_revoke_table_s;
  38
  39  /**
  40 @@ -423,6 +444,7 @@ struct jbd2_revoke_table_s;
  41   * @h_transaction: Which compound transaction is this update a part of?
  42   * @h_buffer_credits: Number of remaining buffers we are allowed to dirty.
  43   * @h_ref: Reference count on this handle
  44 + * @h_jcb: List of application registered callbacks for this handle.
  45   * @h_err: Field for caller's use to track errors through large fs operations
  46   * @h_sync: flag for sync-on-close
  47   * @h_jdata: flag to force data journaling
  48 @@ -448,6 +470,13 @@ struct handle_s
  49         /* operations */
  50         int                     h_err;
  51
  52 +       /*
  53 +        * List of application registered callbacks for this handle. The
  54 +        * function(s) will be called after the transaction that this handle is
  55 +        * part of has been committed to disk. [t_jcb_lock]
  56 +        */
  57 +       struct list_head        h_jcb;
  58 +
  59         /* Flags [no locking] */
  60         unsigned int    h_sync:         1;      /* sync-on-close */
  61         unsigned int    h_jdata:        1;      /* force data journaling */
  62 @@ -503,6 +532,8 @@ struct transaction_chp_stats_s {
  63   *    j_state_lock
  64   *    ->j_list_lock                    (journal_unmap_buffer)
  65   *
  66 + *    t_handle_lock
  67 + *    ->t_jcb_lock
  68   */
  69
  70  struct transaction_s
  71 @@ -659,6 +690,16 @@ struct transaction_s
  72          * structures associated with the transaction
  73          */
  74         struct list_head        t_private_list;
  75 +
  76 +       /*
  77 +        * Protects the callback list
  78 +        */
  79 +       spinlock_t              t_jcb_lock;
  80 +       /*
  81 +        * List of registered callback functions for this transaction.
  82 +        * Called when the transaction is committed. [t_jcb_lock]
  83 +        */
  84 +       struct list_head        t_jcb;
  85  };
  86
  87  struct transaction_run_stats_s {
  88 @@ -1115,6 +1156,9 @@ extern int         jbd2_journal_stop(handle_t *
  89  extern int      jbd2_journal_flush (journal_t *);
  90  extern void     jbd2_journal_lock_updates (journal_t *);
  91  extern void     jbd2_journal_unlock_updates (journal_t *);
  92 +extern void     jbd2_journal_callback_set(handle_t *handle,
  93 +                                      void (*fn)(struct journal_callback *,int),
  94 +                                      struct journal_callback *jcb);
  95
  96  extern journal_t * jbd2_journal_init_dev(struct block_device *bdev,
  97                                 struct block_device *fs_dev,
  98 Index: linux+rh+chaos/fs/jbd2/checkpoint.c
  99 ===================================================================
 100 --- linux+rh+chaos.orig/fs/jbd2/checkpoint.c
 101 +++ linux+rh+chaos/fs/jbd2/checkpoint.c
 102 @@ -759,6 +759,7 @@ void __jbd2_journal_drop_transaction(jou
 103         J_ASSERT(transaction->t_checkpoint_list == NULL);
 104         J_ASSERT(transaction->t_checkpoint_io_list == NULL);
 105         J_ASSERT(transaction->t_updates == 0);
 106 +       J_ASSERT(list_empty(&transaction->t_jcb));
 107         J_ASSERT(journal->j_committing_transaction != transaction);
 108         J_ASSERT(journal->j_running_transaction != transaction);
 109
 110 Index: linux+rh+chaos/fs/jbd2/commit.c
 111 ===================================================================
 112 --- linux+rh+chaos.orig/fs/jbd2/commit.c
 113 +++ linux+rh+chaos/fs/jbd2/commit.c
 114 @@ -857,6 +857,30 @@ wait_for_iobuf:
 115             transaction can be removed from any checkpoint list it was on
 116             before. */
 117
 118 +       /*
 119 +        * Call any callbacks that had been registered for handles in this
 120 +        * transaction.  It is up to the callback to free any allocated
 121 +        * memory.
 122 +        *
 123 +        * The spinlocking (t_jcb_lock) here is surely unnecessary...
 124 +        */
 125 +       spin_lock(&commit_transaction->t_jcb_lock);
 126 +       if (!list_empty(&commit_transaction->t_jcb)) {
 127 +               struct list_head *p, *n;
 128 +               int error = is_journal_aborted(journal);
 129 +
 130 +               list_for_each_safe(p, n, &commit_transaction->t_jcb) {
 131 +                       struct journal_callback *jcb;
 132 +
 133 +                       jcb = list_entry(p, struct journal_callback, jcb_list);
 134 +                       list_del(p);
 135 +                       spin_unlock(&commit_transaction->t_jcb_lock);
 136 +                       jcb->jcb_func(jcb, error);
 137 +                       spin_lock(&commit_transaction->t_jcb_lock);
 138 +               }
 139 +       }
 140 +       spin_unlock(&commit_transaction->t_jcb_lock);
 141 +
 142         jbd_debug(3, "JBD: commit phase 6\n");
 143
 144         J_ASSERT(list_empty(&commit_transaction->t_inode_list));
 145 Index: linux+rh+chaos/fs/jbd2/journal.c
 146 ===================================================================
 147 --- linux+rh+chaos.orig/fs/jbd2/journal.c
 148 +++ linux+rh+chaos/fs/jbd2/journal.c
 149 @@ -90,6 +90,8 @@ EXPORT_SYMBOL(jbd2_journal_file_inode);
 150  EXPORT_SYMBOL(jbd2_journal_init_jbd_inode);
 151  EXPORT_SYMBOL(jbd2_journal_release_jbd_inode);
 152  EXPORT_SYMBOL(jbd2_journal_begin_ordered_truncate);
 153 +EXPORT_SYMBOL(jbd2_journal_callback_set);
 154 +EXPORT_SYMBOL(jbd2_journal_bmap);
 155
 156  static int journal_convert_superblock_v1(journal_t *, journal_superblock_t *);
 157  static void __journal_abort_soft (journal_t *journal, int errno);
 158 Index: linux+rh+chaos/fs/jbd2/transaction.c
 159 ===================================================================
 160 --- linux+rh+chaos.orig/fs/jbd2/transaction.c
 161 +++ linux+rh+chaos/fs/jbd2/transaction.c
 162 @@ -52,7 +52,9 @@ jbd2_get_transaction(journal_t *journal,
 163         transaction->t_start_time = ktime_get();
 164         transaction->t_tid = journal->j_transaction_sequence++;
 165         transaction->t_expires = jiffies + journal->j_commit_interval;
 166 +       INIT_LIST_HEAD(&transaction->t_jcb);
 167         spin_lock_init(&transaction->t_handle_lock);
 168 +       spin_lock_init(&transaction->t_jcb_lock);
 169         INIT_LIST_HEAD(&transaction->t_inode_list);
 170         INIT_LIST_HEAD(&transaction->t_private_list);
 171
 172 @@ -257,6 +259,7 @@ static handle_t *new_handle(int nblocks)
 173         memset(handle, 0, sizeof(*handle));
 174         handle->h_buffer_credits = nblocks;
 175         handle->h_ref = 1;
 176 +       INIT_LIST_HEAD(&handle->h_jcb);
 177
 178         lockdep_init_map(&handle->h_lockdep_map, "jbd2_handle",
 179                                                 &jbd2_handle_key, 0);
 180 @@ -1216,6 +1219,36 @@ drop:
 181  }
 182
 183  /**
 184 + * void jbd2_journal_callback_set() -  Register a callback function for this handle.
 185 + * @handle: handle to attach the callback to.
 186 + * @func: function to callback.
 187 + * @jcb:  structure with additional information required by func() , and
 188 + *     some space for jbd2 internal information.
 189 + *
 190 + * The function will be
 191 + * called when the transaction that this handle is part of has been
 192 + * committed to disk with the original callback data struct and the
 193 + * error status of the journal as parameters.  There is no guarantee of
 194 + * ordering between handles within a single transaction, nor between
 195 + * callbacks registered on the same handle.
 196 + *
 197 + * The caller is responsible for allocating the journal_callback struct.
 198 + * This is to allow the caller to add as much extra data to the callback
 199 + * as needed, but reduce the overhead of multiple allocations.  The caller
 200 + * allocated struct must start with a struct journal_callback at offset 0,
 201 + * and has the caller-specific data afterwards.
 202 + */
 203 +void jbd2_journal_callback_set(handle_t *handle,
 204 +                     void (*func)(struct journal_callback *jcb, int error),
 205 +                     struct journal_callback *jcb)
 206 +{
 207 +       spin_lock(&handle->h_transaction->t_jcb_lock);
 208 +       list_add_tail(&jcb->jcb_list, &handle->h_jcb);
 209 +       spin_unlock(&handle->h_transaction->t_jcb_lock);
 210 +       jcb->jcb_func = func;
 211 +}
 212 +
 213 +/**
 214   * int jbd2_journal_stop() - complete a transaction
 215   * @handle: tranaction to complete.
 216   *
 217 @@ -1321,6 +1354,11 @@ int jbd2_journal_stop(handle_t *handle)
 218                         wake_up(&journal->j_wait_transaction_locked);
 219         }
 220
 221 +       /* Move callbacks from the handle to the transaction. */
 222 +       spin_lock(&transaction->t_jcb_lock);
 223 +       list_splice(&handle->h_jcb, &transaction->t_jcb);
 224 +       spin_unlock(&transaction->t_jcb_lock);
 225 +
 226         /*
 227          * If the handle is marked SYNC, we need to set another commit
 228          * going!  We also want to force a commit if the current