ext4: Enable delalloc by default.

Enable delalloc by default to ensure it gets sufficient testing and
because it makes the filesystem much more efficient.  Add a nodealalloc
option to disable delayed allocation, and update ext4_show_options to
show delayed allocation off if it is disabled.

If the data=journal mount option is used, disable delayed allocation
since the delalloc code doesn't support data=journal yet.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>

1 files changed, 22 insertions, 1 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 25e2f2488cd2..4e104dd0ec21 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -756,6 +756,9 @@ static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
                 seq_puts(seq, ",nomballoc");
         if (test_opt(sb, I_VERSION))
                 seq_puts(seq, ",i_version");
+        if (!test_opt(sb, DELALLOC))
+                seq_puts(seq, ",nodelalloc");
+
 
         if (sbi->s_stripe)
                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
@@ -903,7 +906,7 @@ enum {
         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
         Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
         Opt_grpquota, Opt_extents, Opt_noextents, Opt_i_version,
-        Opt_mballoc, Opt_nomballoc, Opt_stripe, Opt_delalloc,
+        Opt_mballoc, Opt_nomballoc, Opt_stripe, Opt_delalloc, Opt_nodelalloc,
 };
 
 static match_table_t tokens = {
@@ -963,6 +966,7 @@ static match_table_t tokens = {
         {Opt_stripe, "stripe=%u"},
         {Opt_resize, "resize"},
         {Opt_delalloc, "delalloc"},
+        {Opt_nodelalloc, "nodelalloc"},
         {Opt_err, NULL},
 };
 
@@ -1328,6 +1332,9 @@ set_qf_format:
                         set_opt(sbi->s_mount_opt, I_VERSION);
                         sb->s_flags |= MS_I_VERSION;
                         break;
+                case Opt_nodelalloc:
+                        clear_opt(sbi->s_mount_opt, DELALLOC);
+                        break;
                 case Opt_mballoc:
                         set_opt(sbi->s_mount_opt, MBALLOC);
                         break;
@@ -1984,6 +1991,13 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
          */
         set_opt(sbi->s_mount_opt, MBALLOC);
 
+        /*
+         * enable delayed allocation by default
+         * Use -o nodelalloc to turn it off
+         */
+        set_opt(sbi->s_mount_opt, DELALLOC);
+
+
         if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
                             NULL, 0))
                 goto failed_mount;
@@ -2422,6 +2436,13 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
                 test_opt(sb,DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA ? "ordered":
                 "writeback");
 
+        if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
+                printk(KERN_WARNING "EXT4-fs: Ignoring delalloc option - "
+                                "requested data journaling mode\n");
+                clear_opt(sbi->s_mount_opt, DELALLOC);
+        } else if (test_opt(sb, DELALLOC))
+                printk(KERN_INFO "EXT4-fs: delayed allocation enabled\n");
+
         ext4_ext_init(sb);
         ext4_mb_init(sb, needs_recovery);