ocfs2: add a mount option journal_async_commit on ocfs2 filesystem

Add a mount option to support JBD2 feature:

JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT.  When this feature is opened, journal
commit block can be written to disk without waiting for descriptor blocks,
which can improve journal commit performance.  This option will enable
'journal_checksum' internally.

Using the fs_mark benchmark, using journal_async_commit shows a 50%
improvement, the files per second go up from 215.2 to 317.5.

test script:
fs_mark  -d  /mnt/ocfs2/  -s  10240  -n  1000

default:
FSUse%        Count         Size    Files/sec     App Overhead
     0         1000        10240        215.2            17878

with journal_async_commit option:
FSUse%        Count         Size    Files/sec     App Overhead
     0         1000        10240        317.5            17881

Signed-off-by: Alex Chen <alex.chen@huawei.com>
Signed-off-by: Weiwei Wang <wangww631@huawei.comm>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 23 insertions, 0 deletions

diff --git a/Documentation/filesystems/ocfs2.txt b/Documentation/filesystems/ocfs2.txt
index 7618a287aa41..28f8c08201e2 100644
--- a/Documentation/filesystems/ocfs2.txt
+++ b/Documentation/filesystems/ocfs2.txt
@@ -100,3 +100,7 @@ coherency=full  (*)	Disallow concurrent O_DIRECT writes, cluster inode
 coherency=buffered      Allow concurrent O_DIRECT writes without EX lock among
                         nodes, which gains high performance at risk of getting
                         stale data on other nodes.
+journal_async_commit    Commit block can be written to disk without waiting
+                        for descriptor blocks. If enabled older kernels cannot
+                        mount the device. This will enable 'journal_checksum'
+                        internally.
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index 7d6b7d090452..fdbcbfed529e 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -279,6 +279,8 @@ enum ocfs2_mount_options
                                                      writes */
         OCFS2_MOUNT_HB_NONE = 1 << 13, /* No heartbeat */
         OCFS2_MOUNT_HB_GLOBAL = 1 << 14, /* Global heartbeat */
+
+        OCFS2_MOUNT_JOURNAL_ASYNC_COMMIT = 1 << 15,  /* Journal Async Commit */
 };
 
 #define OCFS2_OSB_SOFT_RO       0x0001
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 83723179e1ec..c09d6da23c3d 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -191,6 +191,7 @@ enum {
         Opt_coherency_full,
         Opt_resv_level,
         Opt_dir_resv_level,
+        Opt_journal_async_commit,
         Opt_err,
 };
 
@@ -222,6 +223,7 @@ static const match_table_t tokens = {
         {Opt_coherency_full, "coherency=full"},
         {Opt_resv_level, "resv_level=%u"},
         {Opt_dir_resv_level, "dir_resv_level=%u"},
+        {Opt_journal_async_commit, "journal_async_commit"},
         {Opt_err, NULL}
 };
 
@@ -1500,6 +1502,9 @@ static int ocfs2_parse_options(struct super_block *sb,
                             option < OCFS2_MAX_RESV_LEVEL)
                                 mopt->dir_resv_level = option;
                         break;
+                case Opt_journal_async_commit:
+                        mopt->mount_opt |= OCFS2_MOUNT_JOURNAL_ASYNC_COMMIT;
+                        break;
                 default:
                         mlog(ML_ERROR,
                              "Unrecognized mount option \"%s\" "
@@ -1606,6 +1611,9 @@ static int ocfs2_show_options(struct seq_file *s, struct dentry *root)
         if (osb->osb_dir_resv_level != osb->osb_resv_level)
                 seq_printf(s, ",dir_resv_level=%d", osb->osb_resv_level);
 
+        if (opts & OCFS2_MOUNT_JOURNAL_ASYNC_COMMIT)
+                seq_printf(s, ",journal_async_commit");
+
         return 0;
 }
 
@@ -2475,6 +2483,15 @@ static int ocfs2_check_volume(struct ocfs2_super *osb)
                 goto finally;
         }
 
+        if (osb->s_mount_opt & OCFS2_MOUNT_JOURNAL_ASYNC_COMMIT)
+                jbd2_journal_set_features(osb->journal->j_journal,
+                                JBD2_FEATURE_COMPAT_CHECKSUM, 0,
+                                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
+        else
+                jbd2_journal_clear_features(osb->journal->j_journal,
+                                JBD2_FEATURE_COMPAT_CHECKSUM, 0,
+                                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
+
         if (dirty) {
                 /* recover my local alloc if we didn't unmount cleanly. */
                 status = ocfs2_begin_local_alloc_recovery(osb,