Merge commit 'v2.6.30-rc1' into sched/urgent

Merge reason: update to latest upstream to queue up fix

Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 57 insertions, 24 deletions

diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c
index 3fbffb1ea714..a8e8513a78a9 100644
--- a/fs/jbd/commit.c
+++ b/fs/jbd/commit.c
@@ -20,6 +20,7 @@
 #include <linux/slab.h>
 #include <linux/mm.h>
 #include <linux/pagemap.h>
+#include <linux/bio.h>
 
 /*
  * Default IO end handler for temporary BJ_IO buffer_heads.
@@ -171,14 +172,15 @@ static int journal_write_commit_record(journal_t *journal,
         return (ret == -EIO);
 }
 
-static void journal_do_submit_data(struct buffer_head **wbuf, int bufs)
+static void journal_do_submit_data(struct buffer_head **wbuf, int bufs,
+                                   int write_op)
 {
         int i;
 
         for (i = 0; i < bufs; i++) {
                 wbuf[i]->b_end_io = end_buffer_write_sync;
                 /* We use-up our safety reference in submit_bh() */
-                submit_bh(WRITE, wbuf[i]);
+                submit_bh(write_op, wbuf[i]);
         }
 }
 
@@ -186,7 +188,8 @@ static void journal_do_submit_data(struct buffer_head **wbuf, int bufs)
  *  Submit all the data buffers to disk
  */
 static int journal_submit_data_buffers(journal_t *journal,
-                                transaction_t *commit_transaction)
+                                       transaction_t *commit_transaction,
+                                       int write_op)
 {
         struct journal_head *jh;
         struct buffer_head *bh;
@@ -225,7 +228,7 @@ write_out_data:
                                 BUFFER_TRACE(bh, "needs blocking lock");
                                 spin_unlock(&journal->j_list_lock);
                                 /* Write out all data to prevent deadlocks */
-                                journal_do_submit_data(wbuf, bufs);
+                                journal_do_submit_data(wbuf, bufs, write_op);
                                 bufs = 0;
                                 lock_buffer(bh);
                                 spin_lock(&journal->j_list_lock);
@@ -256,7 +259,7 @@ write_out_data:
                         jbd_unlock_bh_state(bh);
                         if (bufs == journal->j_wbufsize) {
                                 spin_unlock(&journal->j_list_lock);
-                                journal_do_submit_data(wbuf, bufs);
+                                journal_do_submit_data(wbuf, bufs, write_op);
                                 bufs = 0;
                                 goto write_out_data;
                         }
@@ -286,7 +289,7 @@ write_out_data:
                 }
         }
         spin_unlock(&journal->j_list_lock);
-        journal_do_submit_data(wbuf, bufs);
+        journal_do_submit_data(wbuf, bufs, write_op);
 
         return err;
 }
@@ -315,6 +318,7 @@ void journal_commit_transaction(journal_t *journal)
         int first_tag = 0;
         int tag_flag;
         int i;
+        int write_op = WRITE;
 
         /*
          * First job: lock down the current transaction and wait for
@@ -347,6 +351,13 @@ void journal_commit_transaction(journal_t *journal)
         spin_lock(&journal->j_state_lock);
         commit_transaction->t_state = T_LOCKED;
 
+        /*
+         * Use plugged writes here, since we want to submit several before
+         * we unplug the device. We don't do explicit unplugging in here,
+         * instead we rely on sync_buffer() doing the unplug for us.
+         */
+        if (commit_transaction->t_synchronous_commit)
+                write_op = WRITE_SYNC_PLUG;
         spin_lock(&commit_transaction->t_handle_lock);
         while (commit_transaction->t_updates) {
                 DEFINE_WAIT(wait);
@@ -431,7 +442,8 @@ void journal_commit_transaction(journal_t *journal)
          * Now start flushing things to disk, in the order they appear
          * on the transaction lists.  Data blocks go first.
          */
-        err = journal_submit_data_buffers(journal, commit_transaction);
+        err = journal_submit_data_buffers(journal, commit_transaction,
+                                          write_op);
 
         /*
          * Wait for all previously submitted IO to complete.
@@ -660,7 +672,7 @@ start_journal_io:
                                 clear_buffer_dirty(bh);
                                 set_buffer_uptodate(bh);
                                 bh->b_end_io = journal_end_buffer_io_sync;
-                                submit_bh(WRITE, bh);
+                                submit_bh(write_op, bh);
                         }
                         cond_resched();
 
diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c
index 9e4fa52d7dc8..737f7246a4b5 100644
--- a/fs/jbd/journal.c
+++ b/fs/jbd/journal.c
@@ -427,7 +427,7 @@ int __log_space_left(journal_t *journal)
 }
 
 /*
- * Called under j_state_lock.  Returns true if a transaction was started.
+ * Called under j_state_lock.  Returns true if a transaction commit was started.
  */
 int __log_start_commit(journal_t *journal, tid_t target)
 {
@@ -495,7 +495,8 @@ int journal_force_commit_nested(journal_t *journal)
 
 /*
  * Start a commit of the current running transaction (if any).  Returns true
- * if a transaction was started, and fills its tid in at *ptid
+ * if a transaction is going to be committed (or is currently already
+ * committing), and fills its tid in at *ptid
  */
 int journal_start_commit(journal_t *journal, tid_t *ptid)
 {
@@ -505,15 +506,19 @@ int journal_start_commit(journal_t *journal, tid_t *ptid)
         if (journal->j_running_transaction) {
                 tid_t tid = journal->j_running_transaction->t_tid;
 
-                ret = __log_start_commit(journal, tid);
-                if (ret && ptid)
+                __log_start_commit(journal, tid);
+                /* There's a running transaction and we've just made sure
+                 * it's commit has been scheduled. */
+                if (ptid)
                         *ptid = tid;
-        } else if (journal->j_committing_transaction && ptid) {
+                ret = 1;
+        } else if (journal->j_committing_transaction) {
                 /*
                  * If ext3_write_super() recently started a commit, then we
                  * have to wait for completion of that transaction
                  */
-                *ptid = journal->j_committing_transaction->t_tid;
+                if (ptid)
+                        *ptid = journal->j_committing_transaction->t_tid;
                 ret = 1;
         }
         spin_unlock(&journal->j_state_lock);
@@ -632,6 +637,8 @@ struct journal_head *journal_get_descriptor_buffer(journal_t *journal)
                 return NULL;
 
         bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
+        if (!bh)
+                return NULL;
         lock_buffer(bh);
         memset(bh->b_data, 0, journal->j_blocksize);
         set_buffer_uptodate(bh);
@@ -728,9 +735,7 @@ journal_t * journal_init_dev(struct block_device *bdev,
         if (!journal->j_wbuf) {
                 printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
                         __func__);
-                kfree(journal);
-                journal = NULL;
-                goto out;
+                goto out_err;
         }
         journal->j_dev = bdev;
         journal->j_fs_dev = fs_dev;
@@ -738,11 +743,19 @@ journal_t * journal_init_dev(struct block_device *bdev,
         journal->j_maxlen = len;
 
         bh = __getblk(journal->j_dev, start, journal->j_blocksize);
-        J_ASSERT(bh != NULL);
+        if (!bh) {
+                printk(KERN_ERR
+                       "%s: Cannot get buffer for journal superblock\n",
+                       __func__);
+                goto out_err;
+        }
         journal->j_sb_buffer = bh;
         journal->j_superblock = (journal_superblock_t *)bh->b_data;
-out:
+
         return journal;
+out_err:
+        kfree(journal);
+        return NULL;
 }
 
 /**
@@ -782,8 +795,7 @@ journal_t * journal_init_inode (struct inode *inode)
         if (!journal->j_wbuf) {
                 printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
                         __func__);
-                kfree(journal);
-                return NULL;
+                goto out_err;
         }
 
         err = journal_bmap(journal, 0, &blocknr);
@@ -791,16 +803,23 @@ journal_t * journal_init_inode (struct inode *inode)
         if (err) {
                 printk(KERN_ERR "%s: Cannnot locate journal superblock\n",
                        __func__);
-                kfree(journal);
-                return NULL;
+                goto out_err;
         }
 
         bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
-        J_ASSERT(bh != NULL);
+        if (!bh) {
+                printk(KERN_ERR
+                       "%s: Cannot get buffer for journal superblock\n",
+                       __func__);
+                goto out_err;
+        }
         journal->j_sb_buffer = bh;
         journal->j_superblock = (journal_superblock_t *)bh->b_data;
 
         return journal;
+out_err:
+        kfree(journal);
+        return NULL;
 }
 
 /*
diff --git a/fs/jbd/transaction.c b/fs/jbd/transaction.c
index e6a117431277..ed886e6db399 100644
--- a/fs/jbd/transaction.c
+++ b/fs/jbd/transaction.c
@@ -1440,6 +1440,8 @@ int journal_stop(handle_t *handle)
                 }
         }
 
+        if (handle->h_sync)
+                transaction->t_synchronous_commit = 1;
         current->journal_info = NULL;
         spin_lock(&journal->j_state_lock);
         spin_lock(&transaction->t_handle_lock);