nilfs2: issue discard request after cleaning segments

This adds a function to send discard requests for given array of
segment numbers, and calls the function when garbage collection
succeeded.

Signed-off-by: Jiro SEKIBA <jir@unicus.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

1 files changed, 7 insertions, 1 deletions

diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 8173faee31e..3f88401a375 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -481,6 +481,8 @@ static int nilfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
                 seq_printf(seq, ",order=strict");
         if (nilfs_test_opt(sbi, NORECOVERY))
                 seq_printf(seq, ",norecovery");
+        if (nilfs_test_opt(sbi, DISCARD))
+                seq_printf(seq, ",discard");
 
         return 0;
 }
@@ -550,7 +552,7 @@ static const struct export_operations nilfs_export_ops = {
 enum {
         Opt_err_cont, Opt_err_panic, Opt_err_ro,
         Opt_nobarrier, Opt_snapshot, Opt_order, Opt_norecovery,
-        Opt_err,
+        Opt_discard, Opt_err,
 };
 
 static match_table_t tokens = {
@@ -561,6 +563,7 @@ static match_table_t tokens = {
         {Opt_snapshot, "cp=%u"},
         {Opt_order, "order=%s"},
         {Opt_norecovery, "norecovery"},
+        {Opt_discard, "discard"},
         {Opt_err, NULL}
 };
 
@@ -614,6 +617,9 @@ static int parse_options(char *options, struct super_block *sb)
                 case Opt_norecovery:
                         nilfs_set_opt(sbi, NORECOVERY);
                         break;
+                case Opt_discard:
+                        nilfs_set_opt(sbi, DISCARD);
+                        break;
                 default:
                         printk(KERN_ERR
                                "NILFS: Unrecognized mount option \"%s\"\n", p);