1 files changed, 229 insertions, 132 deletions

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 839377e3d624..98ed6dbfe381 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -71,7 +71,6 @@ EXPORT_SYMBOL(jbd2_journal_revoke);
 
 EXPORT_SYMBOL(jbd2_journal_init_dev);
 EXPORT_SYMBOL(jbd2_journal_init_inode);
-EXPORT_SYMBOL(jbd2_journal_update_format);
 EXPORT_SYMBOL(jbd2_journal_check_used_features);
 EXPORT_SYMBOL(jbd2_journal_check_available_features);
 EXPORT_SYMBOL(jbd2_journal_set_features);
@@ -96,7 +95,6 @@ EXPORT_SYMBOL(jbd2_journal_release_jbd_inode);
 EXPORT_SYMBOL(jbd2_journal_begin_ordered_truncate);
 EXPORT_SYMBOL(jbd2_inode_cache);
 
-static int journal_convert_superblock_v1(journal_t *, journal_superblock_t *);
 static void __journal_abort_soft (journal_t *journal, int errno);
 static int jbd2_journal_create_slab(size_t slab_size);
 
@@ -746,6 +744,98 @@ struct journal_head *jbd2_journal_get_descriptor_buffer(journal_t *journal)
         return jbd2_journal_add_journal_head(bh);
 }
 
+/*
+ * Return tid of the oldest transaction in the journal and block in the journal
+ * where the transaction starts.
+ *
+ * If the journal is now empty, return which will be the next transaction ID
+ * we will write and where will that transaction start.
+ *
+ * The return value is 0 if journal tail cannot be pushed any further, 1 if
+ * it can.
+ */
+int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid,
+                              unsigned long *block)
+{
+        transaction_t *transaction;
+        int ret;
+
+        read_lock(&journal->j_state_lock);
+        spin_lock(&journal->j_list_lock);
+        transaction = journal->j_checkpoint_transactions;
+        if (transaction) {
+                *tid = transaction->t_tid;
+                *block = transaction->t_log_start;
+        } else if ((transaction = journal->j_committing_transaction) != NULL) {
+                *tid = transaction->t_tid;
+                *block = transaction->t_log_start;
+        } else if ((transaction = journal->j_running_transaction) != NULL) {
+                *tid = transaction->t_tid;
+                *block = journal->j_head;
+        } else {
+                *tid = journal->j_transaction_sequence;
+                *block = journal->j_head;
+        }
+        ret = tid_gt(*tid, journal->j_tail_sequence);
+        spin_unlock(&journal->j_list_lock);
+        read_unlock(&journal->j_state_lock);
+
+        return ret;
+}
+
+/*
+ * Update information in journal structure and in on disk journal superblock
+ * about log tail. This function does not check whether information passed in
+ * really pushes log tail further. It's responsibility of the caller to make
+ * sure provided log tail information is valid (e.g. by holding
+ * j_checkpoint_mutex all the time between computing log tail and calling this
+ * function as is the case with jbd2_cleanup_journal_tail()).
+ *
+ * Requires j_checkpoint_mutex
+ */
+void __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block)
+{
+        unsigned long freed;
+
+        BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
+
+        /*
+         * We cannot afford for write to remain in drive's caches since as
+         * soon as we update j_tail, next transaction can start reusing journal
+         * space and if we lose sb update during power failure we'd replay
+         * old transaction with possibly newly overwritten data.
+         */
+        jbd2_journal_update_sb_log_tail(journal, tid, block, WRITE_FUA);
+        write_lock(&journal->j_state_lock);
+        freed = block - journal->j_tail;
+        if (block < journal->j_tail)
+                freed += journal->j_last - journal->j_first;
+
+        trace_jbd2_update_log_tail(journal, tid, block, freed);
+        jbd_debug(1,
+                  "Cleaning journal tail from %d to %d (offset %lu), "
+                  "freeing %lu\n",
+                  journal->j_tail_sequence, tid, block, freed);
+
+        journal->j_free += freed;
+        journal->j_tail_sequence = tid;
+        journal->j_tail = block;
+        write_unlock(&journal->j_state_lock);
+}
+
+/*
+ * This is a variaon of __jbd2_update_log_tail which checks for validity of
+ * provided log tail and locks j_checkpoint_mutex. So it is safe against races
+ * with other threads updating log tail.
+ */
+void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block)
+{
+        mutex_lock(&journal->j_checkpoint_mutex);
+        if (tid_gt(tid, journal->j_tail_sequence))
+                __jbd2_update_log_tail(journal, tid, block);
+        mutex_unlock(&journal->j_checkpoint_mutex);
+}
+
 struct jbd2_stats_proc_session {
         journal_t *journal;
         struct transaction_stats_s *stats;
@@ -1114,40 +1204,45 @@ static int journal_reset(journal_t *journal)
 
         journal->j_max_transaction_buffers = journal->j_maxlen / 4;
 
-        /* Add the dynamic fields and write it to disk. */
-        jbd2_journal_update_superblock(journal, 1);
-        return jbd2_journal_start_thread(journal);
-}
-
-/**
- * void jbd2_journal_update_superblock() - Update journal sb on disk.
- * @journal: The journal to update.
- * @wait: Set to '0' if you don't want to wait for IO completion.
- *
- * Update a journal's dynamic superblock fields and write it to disk,
- * optionally waiting for the IO to complete.
- */
-void jbd2_journal_update_superblock(journal_t *journal, int wait)
-{
-        journal_superblock_t *sb = journal->j_superblock;
-        struct buffer_head *bh = journal->j_sb_buffer;
-
         /*
          * As a special case, if the on-disk copy is already marked as needing
-         * no recovery (s_start == 0) and there are no outstanding transactions
-         * in the filesystem, then we can safely defer the superblock update
-         * until the next commit by setting JBD2_FLUSHED.  This avoids
+         * no recovery (s_start == 0), then we can safely defer the superblock
+         * update until the next commit by setting JBD2_FLUSHED.  This avoids
          * attempting a write to a potential-readonly device.
          */
-        if (sb->s_start == 0 && journal->j_tail_sequence ==
-                                journal->j_transaction_sequence) {
+        if (sb->s_start == 0) {
                 jbd_debug(1, "JBD2: Skipping superblock update on recovered sb "
                         "(start %ld, seq %d, errno %d)\n",
                         journal->j_tail, journal->j_tail_sequence,
                         journal->j_errno);
-                goto out;
+                journal->j_flags |= JBD2_FLUSHED;
+        } else {
+                /* Lock here to make assertions happy... */
+                mutex_lock(&journal->j_checkpoint_mutex);
+                /*
+                 * Update log tail information. We use WRITE_FUA since new
+                 * transaction will start reusing journal space and so we
+                 * must make sure information about current log tail is on
+                 * disk before that.
+                 */
+                jbd2_journal_update_sb_log_tail(journal,
+                                                journal->j_tail_sequence,
+                                                journal->j_tail,
+                                                WRITE_FUA);
+                mutex_unlock(&journal->j_checkpoint_mutex);
         }
+        return jbd2_journal_start_thread(journal);
+}
 
+static void jbd2_write_superblock(journal_t *journal, int write_op)
+{
+        struct buffer_head *bh = journal->j_sb_buffer;
+        int ret;
+
+        trace_jbd2_write_superblock(journal, write_op);
+        if (!(journal->j_flags & JBD2_BARRIER))
+                write_op &= ~(REQ_FUA | REQ_FLUSH);
+        lock_buffer(bh);
         if (buffer_write_io_error(bh)) {
                 /*
                  * Oh, dear.  A previous attempt to write the journal
@@ -1163,48 +1258,106 @@ void jbd2_journal_update_superblock(journal_t *journal, int wait)
                 clear_buffer_write_io_error(bh);
                 set_buffer_uptodate(bh);
         }
+        get_bh(bh);
+        bh->b_end_io = end_buffer_write_sync;
+        ret = submit_bh(write_op, bh);
+        wait_on_buffer(bh);
+        if (buffer_write_io_error(bh)) {
+                clear_buffer_write_io_error(bh);
+                set_buffer_uptodate(bh);
+                ret = -EIO;
+        }
+        if (ret) {
+                printk(KERN_ERR "JBD2: Error %d detected when updating "
+                       "journal superblock for %s.\n", ret,
+                       journal->j_devname);
+        }
+}
+
+/**
+ * jbd2_journal_update_sb_log_tail() - Update log tail in journal sb on disk.
+ * @journal: The journal to update.
+ * @tail_tid: TID of the new transaction at the tail of the log
+ * @tail_block: The first block of the transaction at the tail of the log
+ * @write_op: With which operation should we write the journal sb
+ *
+ * Update a journal's superblock information about log tail and write it to
+ * disk, waiting for the IO to complete.
+ */
+void jbd2_journal_update_sb_log_tail(journal_t *journal, tid_t tail_tid,
+                                     unsigned long tail_block, int write_op)
+{
+        journal_superblock_t *sb = journal->j_superblock;
+
+        BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
+        jbd_debug(1, "JBD2: updating superblock (start %lu, seq %u)\n",
+                  tail_block, tail_tid);
+
+        sb->s_sequence = cpu_to_be32(tail_tid);
+        sb->s_start    = cpu_to_be32(tail_block);
+
+        jbd2_write_superblock(journal, write_op);
+
+        /* Log is no longer empty */
+        write_lock(&journal->j_state_lock);
+        WARN_ON(!sb->s_sequence);
+        journal->j_flags &= ~JBD2_FLUSHED;
+        write_unlock(&journal->j_state_lock);
+}
+
+/**
+ * jbd2_mark_journal_empty() - Mark on disk journal as empty.
+ * @journal: The journal to update.
+ *
+ * Update a journal's dynamic superblock fields to show that journal is empty.
+ * Write updated superblock to disk waiting for IO to complete.
+ */
+static void jbd2_mark_journal_empty(journal_t *journal)
+{
+        journal_superblock_t *sb = journal->j_superblock;
 
+        BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
         read_lock(&journal->j_state_lock);
-        jbd_debug(1, "JBD2: updating superblock (start %ld, seq %d, errno %d)\n",
-                  journal->j_tail, journal->j_tail_sequence, journal->j_errno);
+        jbd_debug(1, "JBD2: Marking journal as empty (seq %d)\n",
+                  journal->j_tail_sequence);
 
         sb->s_sequence = cpu_to_be32(journal->j_tail_sequence);
-        sb->s_start    = cpu_to_be32(journal->j_tail);
-        sb->s_errno    = cpu_to_be32(journal->j_errno);
+        sb->s_start    = cpu_to_be32(0);
         read_unlock(&journal->j_state_lock);
 
-        BUFFER_TRACE(bh, "marking dirty");
-        mark_buffer_dirty(bh);
-        if (wait) {
-                sync_dirty_buffer(bh);
-                if (buffer_write_io_error(bh)) {
-                        printk(KERN_ERR "JBD2: I/O error detected "
-                               "when updating journal superblock for %s.\n",
-                               journal->j_devname);
-                        clear_buffer_write_io_error(bh);
-                        set_buffer_uptodate(bh);
-                }
-        } else
-                write_dirty_buffer(bh, WRITE);
-
-out:
-        /* If we have just flushed the log (by marking s_start==0), then
-         * any future commit will have to be careful to update the
-         * superblock again to re-record the true start of the log. */
+        jbd2_write_superblock(journal, WRITE_FUA);
 
+        /* Log is no longer empty */
         write_lock(&journal->j_state_lock);
-        if (sb->s_start)
-                journal->j_flags &= ~JBD2_FLUSHED;
-        else
-                journal->j_flags |= JBD2_FLUSHED;
+        journal->j_flags |= JBD2_FLUSHED;
         write_unlock(&journal->j_state_lock);
 }
 
+
+/**
+ * jbd2_journal_update_sb_errno() - Update error in the journal.
+ * @journal: The journal to update.
+ *
+ * Update a journal's errno.  Write updated superblock to disk waiting for IO
+ * to complete.
+ */
+static void jbd2_journal_update_sb_errno(journal_t *journal)
+{
+        journal_superblock_t *sb = journal->j_superblock;
+
+        read_lock(&journal->j_state_lock);
+        jbd_debug(1, "JBD2: updating superblock error (errno %d)\n",
+                  journal->j_errno);
+        sb->s_errno    = cpu_to_be32(journal->j_errno);
+        read_unlock(&journal->j_state_lock);
+
+        jbd2_write_superblock(journal, WRITE_SYNC);
+}
+
 /*
  * Read the superblock for a given journal, performing initial
  * validation of the format.
  */
-
 static int journal_get_superblock(journal_t *journal)
 {
         struct buffer_head *bh;
@@ -1398,14 +1551,11 @@ int jbd2_journal_destroy(journal_t *journal)
 
         if (journal->j_sb_buffer) {
                 if (!is_journal_aborted(journal)) {
-                        /* We can now mark the journal as empty. */
-                        journal->j_tail = 0;
-                        journal->j_tail_sequence =
-                                ++journal->j_transaction_sequence;
-                        jbd2_journal_update_superblock(journal, 1);
-                } else {
+                        mutex_lock(&journal->j_checkpoint_mutex);
+                        jbd2_mark_journal_empty(journal);
+                        mutex_unlock(&journal->j_checkpoint_mutex);
+                } else
                         err = -EIO;
-                }
                 brelse(journal->j_sb_buffer);
         }
 
@@ -1552,61 +1702,6 @@ void jbd2_journal_clear_features(journal_t *journal, unsigned long compat,
 EXPORT_SYMBOL(jbd2_journal_clear_features);
 
 /**
- * int jbd2_journal_update_format () - Update on-disk journal structure.
- * @journal: Journal to act on.
- *
- * Given an initialised but unloaded journal struct, poke about in the
- * on-disk structure to update it to the most recent supported version.
- */
-int jbd2_journal_update_format (journal_t *journal)
-{
-        journal_superblock_t *sb;
-        int err;
-
-        err = journal_get_superblock(journal);
-        if (err)
-                return err;
-
-        sb = journal->j_superblock;
-
-        switch (be32_to_cpu(sb->s_header.h_blocktype)) {
-        case JBD2_SUPERBLOCK_V2:
-                return 0;
-        case JBD2_SUPERBLOCK_V1:
-                return journal_convert_superblock_v1(journal, sb);
-        default:
-                break;
-        }
-        return -EINVAL;
-}
-
-static int journal_convert_superblock_v1(journal_t *journal,
-                                         journal_superblock_t *sb)
-{
-        int offset, blocksize;
-        struct buffer_head *bh;
-
-        printk(KERN_WARNING
-                "JBD2: Converting superblock from version 1 to 2.\n");
-
-        /* Pre-initialise new fields to zero */
-        offset = ((char *) &(sb->s_feature_compat)) - ((char *) sb);
-        blocksize = be32_to_cpu(sb->s_blocksize);
-        memset(&sb->s_feature_compat, 0, blocksize-offset);
-
-        sb->s_nr_users = cpu_to_be32(1);
-        sb->s_header.h_blocktype = cpu_to_be32(JBD2_SUPERBLOCK_V2);
-        journal->j_format_version = 2;
-
-        bh = journal->j_sb_buffer;
-        BUFFER_TRACE(bh, "marking dirty");
-        mark_buffer_dirty(bh);
-        sync_dirty_buffer(bh);
-        return 0;
-}
-
-
-/**
  * int jbd2_journal_flush () - Flush journal
  * @journal: Journal to act on.
  *
@@ -1619,7 +1714,6 @@ int jbd2_journal_flush(journal_t *journal)
 {
         int err = 0;
         transaction_t *transaction = NULL;
-        unsigned long old_tail;
 
         write_lock(&journal->j_state_lock);
 
@@ -1654,6 +1748,7 @@ int jbd2_journal_flush(journal_t *journal)
         if (is_journal_aborted(journal))
                 return -EIO;
 
+        mutex_lock(&journal->j_checkpoint_mutex);
         jbd2_cleanup_journal_tail(journal);
 
         /* Finally, mark the journal as really needing no recovery.
@@ -1661,14 +1756,9 @@ int jbd2_journal_flush(journal_t *journal)
          * the magic code for a fully-recovered superblock.  Any future
          * commits of data to the journal will restore the current
          * s_start value. */
+        jbd2_mark_journal_empty(journal);
+        mutex_unlock(&journal->j_checkpoint_mutex);
         write_lock(&journal->j_state_lock);
-        old_tail = journal->j_tail;
-        journal->j_tail = 0;
-        write_unlock(&journal->j_state_lock);
-        jbd2_journal_update_superblock(journal, 1);
-        write_lock(&journal->j_state_lock);
-        journal->j_tail = old_tail;
-
         J_ASSERT(!journal->j_running_transaction);
         J_ASSERT(!journal->j_committing_transaction);
         J_ASSERT(!journal->j_checkpoint_transactions);
@@ -1708,8 +1798,12 @@ int jbd2_journal_wipe(journal_t *journal, int write)
                 write ? "Clearing" : "Ignoring");
 
         err = jbd2_journal_skip_recovery(journal);
-        if (write)
-                jbd2_journal_update_superblock(journal, 1);
+        if (write) {
+                /* Lock to make assertions happy... */
+                mutex_lock(&journal->j_checkpoint_mutex);
+                jbd2_mark_journal_empty(journal);
+                mutex_unlock(&journal->j_checkpoint_mutex);
+        }
 
  no_recovery:
         return err;
@@ -1759,7 +1853,7 @@ static void __journal_abort_soft (journal_t *journal, int errno)
         __jbd2_journal_abort_hard(journal);
 
         if (errno)
-                jbd2_journal_update_superblock(journal, 1);
+                jbd2_journal_update_sb_errno(journal);
 }
 
 /**
@@ -2017,7 +2111,7 @@ static struct kmem_cache *jbd2_journal_head_cache;
 static atomic_t nr_journal_heads = ATOMIC_INIT(0);
 #endif
 
-static int journal_init_jbd2_journal_head_cache(void)
+static int jbd2_journal_init_journal_head_cache(void)
 {
         int retval;
 
@@ -2035,7 +2129,7 @@ static int journal_init_jbd2_journal_head_cache(void)
         return retval;
 }
 
-static void jbd2_journal_destroy_jbd2_journal_head_cache(void)
+static void jbd2_journal_destroy_journal_head_cache(void)
 {
         if (jbd2_journal_head_cache) {
                 kmem_cache_destroy(jbd2_journal_head_cache);
@@ -2323,7 +2417,7 @@ static void __exit jbd2_remove_jbd_stats_proc_entry(void)
 
 struct kmem_cache *jbd2_handle_cache, *jbd2_inode_cache;
 
-static int __init journal_init_handle_cache(void)
+static int __init jbd2_journal_init_handle_cache(void)
 {
         jbd2_handle_cache = KMEM_CACHE(jbd2_journal_handle, SLAB_TEMPORARY);
         if (jbd2_handle_cache == NULL) {
@@ -2358,17 +2452,20 @@ static int __init journal_init_caches(void)
 
         ret = jbd2_journal_init_revoke_caches();
         if (ret == 0)
-                ret = journal_init_jbd2_journal_head_cache();
+                ret = jbd2_journal_init_journal_head_cache();
+        if (ret == 0)
+                ret = jbd2_journal_init_handle_cache();
         if (ret == 0)
-                ret = journal_init_handle_cache();
+                ret = jbd2_journal_init_transaction_cache();
         return ret;
 }
 
 static void jbd2_journal_destroy_caches(void)
 {
         jbd2_journal_destroy_revoke_caches();
-        jbd2_journal_destroy_jbd2_journal_head_cache();
+        jbd2_journal_destroy_journal_head_cache();
         jbd2_journal_destroy_handle_cache();
+        jbd2_journal_destroy_transaction_cache();
         jbd2_journal_destroy_slabs();
 }