4 files changed, 137 insertions, 143 deletions

diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index a8173081f831..e0139786f717 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -520,22 +520,6 @@ void jbd2_journal_commit_transaction(journal_t *journal)
         jbd_debug (3, "JBD: commit phase 2\n");
 
         /*
-         * First, drop modified flag: all accesses to the buffers
-         * will be tracked for a new trasaction only -bzzz
-         */
-        spin_lock(&journal->j_list_lock);
-        if (commit_transaction->t_buffers) {
-                new_jh = jh = commit_transaction->t_buffers->b_tnext;
-                do {
-                        J_ASSERT_JH(new_jh, new_jh->b_modified == 1 ||
-                                        new_jh->b_modified == 0);
-                        new_jh->b_modified = 0;
-                        new_jh = new_jh->b_tnext;
-                } while (new_jh != jh);
-        }
-        spin_unlock(&journal->j_list_lock);
-
-        /*
          * Now start flushing things to disk, in the order they appear
          * on the transaction lists.  Data blocks go first.
          */
@@ -584,6 +568,9 @@ void jbd2_journal_commit_transaction(journal_t *journal)
         stats.u.run.rs_blocks = commit_transaction->t_outstanding_credits;
         stats.u.run.rs_blocks_logged = 0;
 
+        J_ASSERT(commit_transaction->t_nr_buffers <=
+                 commit_transaction->t_outstanding_credits);
+
         descriptor = NULL;
         bufs = 0;
         while (commit_transaction->t_buffers) {
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 954cff001df6..53632e3e8457 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -534,7 +534,7 @@ int jbd2_log_wait_commit(journal_t *journal, tid_t tid)
         if (!tid_geq(journal->j_commit_request, tid)) {
                 printk(KERN_EMERG
                        "%s: error: j_commit_request=%d, tid=%d\n",
-                       __FUNCTION__, journal->j_commit_request, tid);
+                       __func__, journal->j_commit_request, tid);
         }
         spin_unlock(&journal->j_state_lock);
 #endif
@@ -599,7 +599,7 @@ int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr,
 
                         printk(KERN_ALERT "%s: journal block not found "
                                         "at offset %lu on %s\n",
-                                __FUNCTION__,
+                                __func__,
                                 blocknr,
                                 bdevname(journal->j_dev, b));
                         err = -EIO;
@@ -904,19 +904,10 @@ static void jbd2_stats_proc_init(journal_t *journal)
         snprintf(name, sizeof(name) - 1, "%s", bdevname(journal->j_dev, name));
         journal->j_proc_entry = proc_mkdir(name, proc_jbd2_stats);
         if (journal->j_proc_entry) {
-                struct proc_dir_entry *p;
-                p = create_proc_entry("history", S_IRUGO,
-                                journal->j_proc_entry);
-                if (p) {
-                        p->proc_fops = &jbd2_seq_history_fops;
-                        p->data = journal;
-                        p = create_proc_entry("info", S_IRUGO,
-                                                journal->j_proc_entry);
-                        if (p) {
-                                p->proc_fops = &jbd2_seq_info_fops;
-                                p->data = journal;
-                        }
-                }
+                proc_create_data("history", S_IRUGO, journal->j_proc_entry,
+                                 &jbd2_seq_history_fops, journal);
+                proc_create_data("info", S_IRUGO, journal->j_proc_entry,
+                                 &jbd2_seq_info_fops, journal);
         }
 }
 
@@ -1006,13 +997,14 @@ fail:
  */
 
 /**
- *  journal_t * jbd2_journal_init_dev() - creates an initialises a journal structure
+ *  journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure
  *  @bdev: Block device on which to create the journal
  *  @fs_dev: Device which hold journalled filesystem for this journal.
  *  @start: Block nr Start of journal.
  *  @len:  Length of the journal in blocks.
  *  @blocksize: blocksize of journalling device
- *  @returns: a newly created journal_t *
+ *
+ *  Returns: a newly created journal_t *
  *
  *  jbd2_journal_init_dev creates a journal which maps a fixed contiguous
  *  range of blocks on an arbitrary block device.
@@ -1036,7 +1028,7 @@ journal_t * jbd2_journal_init_dev(struct block_device *bdev,
         journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
         if (!journal->j_wbuf) {
                 printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
-                        __FUNCTION__);
+                        __func__);
                 kfree(journal);
                 journal = NULL;
                 goto out;
@@ -1092,7 +1084,7 @@ journal_t * jbd2_journal_init_inode (struct inode *inode)
         journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
         if (!journal->j_wbuf) {
                 printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
-                        __FUNCTION__);
+                        __func__);
                 kfree(journal);
                 return NULL;
         }
@@ -1101,7 +1093,7 @@ journal_t * jbd2_journal_init_inode (struct inode *inode)
         /* If that failed, give up */
         if (err) {
                 printk(KERN_ERR "%s: Cannnot locate journal superblock\n",
-                       __FUNCTION__);
+                       __func__);
                 kfree(journal);
                 return NULL;
         }
@@ -1187,7 +1179,7 @@ int jbd2_journal_create(journal_t *journal)
                  */
                 printk(KERN_EMERG
                        "%s: creation of journal on external device!\n",
-                       __FUNCTION__);
+                       __func__);
                 BUG();
         }
 
@@ -1985,9 +1977,10 @@ static int journal_init_jbd2_journal_head_cache(void)
 
 static void jbd2_journal_destroy_jbd2_journal_head_cache(void)
 {
-        J_ASSERT(jbd2_journal_head_cache != NULL);
-        kmem_cache_destroy(jbd2_journal_head_cache);
-        jbd2_journal_head_cache = NULL;
+        if (jbd2_journal_head_cache) {
+                kmem_cache_destroy(jbd2_journal_head_cache);
+                jbd2_journal_head_cache = NULL;
+        }
 }
 
 /*
@@ -2006,7 +1999,7 @@ static struct journal_head *journal_alloc_journal_head(void)
                 jbd_debug(1, "out of memory for journal_head\n");
                 if (time_after(jiffies, last_warning + 5*HZ)) {
                         printk(KERN_NOTICE "ENOMEM in %s, retrying.\n",
-                               __FUNCTION__);
+                               __func__);
                         last_warning = jiffies;
                 }
                 while (!ret) {
@@ -2143,13 +2136,13 @@ static void __journal_remove_journal_head(struct buffer_head *bh)
                         if (jh->b_frozen_data) {
                                 printk(KERN_WARNING "%s: freeing "
                                                 "b_frozen_data\n",
-                                                __FUNCTION__);
+                                                __func__);
                                 jbd2_free(jh->b_frozen_data, bh->b_size);
                         }
                         if (jh->b_committed_data) {
                                 printk(KERN_WARNING "%s: freeing "
                                                 "b_committed_data\n",
-                                                __FUNCTION__);
+                                                __func__);
                                 jbd2_free(jh->b_committed_data, bh->b_size);
                         }
                         bh->b_private = NULL;
@@ -2314,10 +2307,12 @@ static int __init journal_init(void)
         BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024);
 
         ret = journal_init_caches();
-        if (ret != 0)
+        if (ret == 0) {
+                jbd2_create_debugfs_entry();
+                jbd2_create_jbd_stats_proc_entry();
+        } else {
                 jbd2_journal_destroy_caches();
-        jbd2_create_debugfs_entry();
-        jbd2_create_jbd_stats_proc_entry();
+        }
         return ret;
 }
 
diff --git a/fs/jbd2/revoke.c b/fs/jbd2/revoke.c
index 2e1453a5e998..257ff2625765 100644
--- a/fs/jbd2/revoke.c
+++ b/fs/jbd2/revoke.c
@@ -139,7 +139,7 @@ repeat:
 oom:
         if (!journal_oom_retry)
                 return -ENOMEM;
-        jbd_debug(1, "ENOMEM in %s, retrying\n", __FUNCTION__);
+        jbd_debug(1, "ENOMEM in %s, retrying\n", __func__);
         yield();
         goto repeat;
 }
@@ -167,138 +167,121 @@ static struct jbd2_revoke_record_s *find_revoke_record(journal_t *journal,
         return NULL;
 }
 
+void jbd2_journal_destroy_revoke_caches(void)
+{
+        if (jbd2_revoke_record_cache) {
+                kmem_cache_destroy(jbd2_revoke_record_cache);
+                jbd2_revoke_record_cache = NULL;
+        }
+        if (jbd2_revoke_table_cache) {
+                kmem_cache_destroy(jbd2_revoke_table_cache);
+                jbd2_revoke_table_cache = NULL;
+        }
+}
+
 int __init jbd2_journal_init_revoke_caches(void)
 {
+        J_ASSERT(!jbd2_revoke_record_cache);
+        J_ASSERT(!jbd2_revoke_table_cache);
+
         jbd2_revoke_record_cache = kmem_cache_create("jbd2_revoke_record",
                                            sizeof(struct jbd2_revoke_record_s),
                                            0,
                                            SLAB_HWCACHE_ALIGN|SLAB_TEMPORARY,
                                            NULL);
         if (!jbd2_revoke_record_cache)
-                return -ENOMEM;
+                goto record_cache_failure;
 
         jbd2_revoke_table_cache = kmem_cache_create("jbd2_revoke_table",
                                            sizeof(struct jbd2_revoke_table_s),
                                            0, SLAB_TEMPORARY, NULL);
-        if (!jbd2_revoke_table_cache) {
-                kmem_cache_destroy(jbd2_revoke_record_cache);
-                jbd2_revoke_record_cache = NULL;
-                return -ENOMEM;
-        }
+        if (!jbd2_revoke_table_cache)
+                goto table_cache_failure;
         return 0;
+table_cache_failure:
+        jbd2_journal_destroy_revoke_caches();
+record_cache_failure:
+                return -ENOMEM;
 }
 
-void jbd2_journal_destroy_revoke_caches(void)
+static struct jbd2_revoke_table_s *jbd2_journal_init_revoke_table(int hash_size)
 {
-        kmem_cache_destroy(jbd2_revoke_record_cache);
-        jbd2_revoke_record_cache = NULL;
-        kmem_cache_destroy(jbd2_revoke_table_cache);
-        jbd2_revoke_table_cache = NULL;
-}
-
-/* Initialise the revoke table for a given journal to a given size. */
-
-int jbd2_journal_init_revoke(journal_t *journal, int hash_size)
-{
-        int shift, tmp;
+        int shift = 0;
+        int tmp = hash_size;
+        struct jbd2_revoke_table_s *table;
 
-        J_ASSERT (journal->j_revoke_table[0] == NULL);
+        table = kmem_cache_alloc(jbd2_revoke_table_cache, GFP_KERNEL);
+        if (!table)
+                goto out;
 
-        shift = 0;
-        tmp = hash_size;
         while((tmp >>= 1UL) != 0UL)
                 shift++;
 
-        journal->j_revoke_table[0] = kmem_cache_alloc(jbd2_revoke_table_cache, GFP_KERNEL);
-        if (!journal->j_revoke_table[0])
-                return -ENOMEM;
-        journal->j_revoke = journal->j_revoke_table[0];
-
-        /* Check that the hash_size is a power of two */
-        J_ASSERT(is_power_of_2(hash_size));
-
-        journal->j_revoke->hash_size = hash_size;
-
-        journal->j_revoke->hash_shift = shift;
-
-        journal->j_revoke->hash_table =
+        table->hash_size = hash_size;
+        table->hash_shift = shift;
+        table->hash_table =
                 kmalloc(hash_size * sizeof(struct list_head), GFP_KERNEL);
-        if (!journal->j_revoke->hash_table) {
-                kmem_cache_free(jbd2_revoke_table_cache, journal->j_revoke_table[0]);
-                journal->j_revoke = NULL;
-                return -ENOMEM;
+        if (!table->hash_table) {
+                kmem_cache_free(jbd2_revoke_table_cache, table);
+                table = NULL;
+                goto out;
         }
 
         for (tmp = 0; tmp < hash_size; tmp++)
-                INIT_LIST_HEAD(&journal->j_revoke->hash_table[tmp]);
+                INIT_LIST_HEAD(&table->hash_table[tmp]);
 
-        journal->j_revoke_table[1] = kmem_cache_alloc(jbd2_revoke_table_cache, GFP_KERNEL);
-        if (!journal->j_revoke_table[1]) {
-                kfree(journal->j_revoke_table[0]->hash_table);
-                kmem_cache_free(jbd2_revoke_table_cache, journal->j_revoke_table[0]);
-                return -ENOMEM;
+out:
+        return table;
+}
+
+static void jbd2_journal_destroy_revoke_table(struct jbd2_revoke_table_s *table)
+{
+        int i;
+        struct list_head *hash_list;
+
+        for (i = 0; i < table->hash_size; i++) {
+                hash_list = &table->hash_table[i];
+                J_ASSERT(list_empty(hash_list));
         }
 
-        journal->j_revoke = journal->j_revoke_table[1];
+        kfree(table->hash_table);
+        kmem_cache_free(jbd2_revoke_table_cache, table);
+}
 
-        /* Check that the hash_size is a power of two */
+/* Initialise the revoke table for a given journal to a given size. */
+int jbd2_journal_init_revoke(journal_t *journal, int hash_size)
+{
+        J_ASSERT(journal->j_revoke_table[0] == NULL);
         J_ASSERT(is_power_of_2(hash_size));
 
-        journal->j_revoke->hash_size = hash_size;
-
-        journal->j_revoke->hash_shift = shift;
+        journal->j_revoke_table[0] = jbd2_journal_init_revoke_table(hash_size);
+        if (!journal->j_revoke_table[0])
+                goto fail0;
 
-        journal->j_revoke->hash_table =
-                kmalloc(hash_size * sizeof(struct list_head), GFP_KERNEL);
-        if (!journal->j_revoke->hash_table) {
-                kfree(journal->j_revoke_table[0]->hash_table);
-                kmem_cache_free(jbd2_revoke_table_cache, journal->j_revoke_table[0]);
-                kmem_cache_free(jbd2_revoke_table_cache, journal->j_revoke_table[1]);
-                journal->j_revoke = NULL;
-                return -ENOMEM;
-        }
+        journal->j_revoke_table[1] = jbd2_journal_init_revoke_table(hash_size);
+        if (!journal->j_revoke_table[1])
+                goto fail1;
 
-        for (tmp = 0; tmp < hash_size; tmp++)
-                INIT_LIST_HEAD(&journal->j_revoke->hash_table[tmp]);
+        journal->j_revoke = journal->j_revoke_table[1];
 
         spin_lock_init(&journal->j_revoke_lock);
 
         return 0;
-}
 
-/* Destoy a journal's revoke table.  The table must already be empty! */
+fail1:
+        jbd2_journal_destroy_revoke_table(journal->j_revoke_table[0]);
+fail0:
+        return -ENOMEM;
+}
 
+/* Destroy a journal's revoke table.  The table must already be empty! */
 void jbd2_journal_destroy_revoke(journal_t *journal)
 {
-        struct jbd2_revoke_table_s *table;
-        struct list_head *hash_list;
-        int i;
-
-        table = journal->j_revoke_table[0];
-        if (!table)
-                return;
-
-        for (i=0; i<table->hash_size; i++) {
-                hash_list = &table->hash_table[i];
-                J_ASSERT (list_empty(hash_list));
-        }
-
-        kfree(table->hash_table);
-        kmem_cache_free(jbd2_revoke_table_cache, table);
-        journal->j_revoke = NULL;
-
-        table = journal->j_revoke_table[1];
-        if (!table)
-                return;
-
-        for (i=0; i<table->hash_size; i++) {
-                hash_list = &table->hash_table[i];
-                J_ASSERT (list_empty(hash_list));
-        }
-
-        kfree(table->hash_table);
-        kmem_cache_free(jbd2_revoke_table_cache, table);
         journal->j_revoke = NULL;
+        if (journal->j_revoke_table[0])
+                jbd2_journal_destroy_revoke_table(journal->j_revoke_table[0]);
+        if (journal->j_revoke_table[1])
+                jbd2_journal_destroy_revoke_table(journal->j_revoke_table[1]);
 }
 
 
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index b9b0b6f899b9..d6e006e67804 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -618,6 +618,12 @@ repeat:
                 goto done;
 
         /*
+         * this is the first time this transaction is touching this buffer,
+         * reset the modified flag
+         */
+       jh->b_modified = 0;
+
+        /*
          * If there is already a copy-out version of this buffer, then we don't
          * need to make another one
          */
@@ -690,7 +696,7 @@ repeat:
                                 if (!frozen_buffer) {
                                         printk(KERN_EMERG
                                                "%s: OOM for frozen_buffer\n",
-                                               __FUNCTION__);
+                                               __func__);
                                         JBUFFER_TRACE(jh, "oom!");
                                         error = -ENOMEM;
                                         jbd_lock_bh_state(bh);
@@ -829,9 +835,16 @@ int jbd2_journal_get_create_access(handle_t *handle, struct buffer_head *bh)
 
         if (jh->b_transaction == NULL) {
                 jh->b_transaction = transaction;
+
+                /* first access by this transaction */
+                jh->b_modified = 0;
+
                 JBUFFER_TRACE(jh, "file as BJ_Reserved");
                 __jbd2_journal_file_buffer(jh, transaction, BJ_Reserved);
         } else if (jh->b_transaction == journal->j_committing_transaction) {
+                /* first access by this transaction */
+                jh->b_modified = 0;
+
                 JBUFFER_TRACE(jh, "set next transaction");
                 jh->b_next_transaction = transaction;
         }
@@ -901,7 +914,7 @@ repeat:
                 committed_data = jbd2_alloc(jh2bh(jh)->b_size, GFP_NOFS);
                 if (!committed_data) {
                         printk(KERN_EMERG "%s: No memory for committed data\n",
-                                __FUNCTION__);
+                                __func__);
                         err = -ENOMEM;
                         goto out;
                 }
@@ -1230,6 +1243,7 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh)
         struct journal_head *jh;
         int drop_reserve = 0;
         int err = 0;
+        int was_modified = 0;
 
         BUFFER_TRACE(bh, "entry");
 
@@ -1248,6 +1262,9 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh)
                 goto not_jbd;
         }
 
+        /* keep track of wether or not this transaction modified us */
+        was_modified = jh->b_modified;
+
         /*
          * The buffer's going from the transaction, we must drop
          * all references -bzzz
@@ -1265,7 +1282,12 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh)
 
                 JBUFFER_TRACE(jh, "belongs to current transaction: unfile");
 
-                drop_reserve = 1;
+                /*
+                 * we only want to drop a reference if this transaction
+                 * modified the buffer
+                 */
+                if (was_modified)
+                        drop_reserve = 1;
 
                 /*
                  * We are no longer going to journal this buffer.
@@ -1305,7 +1327,13 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh)
                 if (jh->b_next_transaction) {
                         J_ASSERT(jh->b_next_transaction == transaction);
                         jh->b_next_transaction = NULL;
-                        drop_reserve = 1;
+
+                        /*
+                         * only drop a reference if this transaction modified
+                         * the buffer
+                         */
+                        if (was_modified)
+                                drop_reserve = 1;
                 }
         }
 
@@ -1434,7 +1462,8 @@ int jbd2_journal_stop(handle_t *handle)
         return err;
 }
 
-/**int jbd2_journal_force_commit() - force any uncommitted transactions
+/**
+ * int jbd2_journal_force_commit() - force any uncommitted transactions
  * @journal: journal to force
  *
  * For synchronous operations: force any uncommitted transactions
@@ -2077,7 +2106,7 @@ void __jbd2_journal_refile_buffer(struct journal_head *jh)
         jh->b_transaction = jh->b_next_transaction;
         jh->b_next_transaction = NULL;
         __jbd2_journal_file_buffer(jh, jh->b_transaction,
-                                was_dirty ? BJ_Metadata : BJ_Reserved);
+                                jh->b_modified ? BJ_Metadata : BJ_Reserved);
         J_ASSERT_JH(jh, jh->b_transaction->t_state == T_RUNNING);
 
         if (was_dirty)