f2fs: add nodiscard mount option

This patch adds 'nodiscard' mount option.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
index 3a5ce24..ecd8080 100644 (file)
--- a/Documentation/filesystems/f2fs.txt
+++ b/Documentation/filesystems/f2fs.txt
@@ -109,7 +109,9 @@ background_gc=%s       Turn on/off cleaning operations, namely garbage
 disable_roll_forward   Disable the roll-forward recovery routine
 norecovery             Disable the roll-forward recovery routine, mounted read-
                        only (i.e., -o ro,disable_roll_forward)
-discard                Issue discard/TRIM commands when a segment is cleaned.
+discard/nodiscard      Enable/disable real-time discard in f2fs, if discard is
+                       enabled, f2fs will issue discard/TRIM commands when a
+                      segment is cleaned.
 no_heap                Disable heap-style segment allocation which finds free
                        segments for data from the beginning of main area, while
                       for node from the end of main area.

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 8c698e1..e0a975d 100644 (file)
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -76,6 +76,7 @@ enum {
        Opt_disable_roll_forward,
        Opt_norecovery,
        Opt_discard,
+       Opt_nodiscard,
        Opt_noheap,
        Opt_user_xattr,
        Opt_nouser_xattr,
@@ -106,6 +107,7 @@ static match_table_t f2fs_tokens = {
        {Opt_disable_roll_forward, "disable_roll_forward"},
        {Opt_norecovery, "norecovery"},
        {Opt_discard, "discard"},
+       {Opt_nodiscard, "nodiscard"},
        {Opt_noheap, "no_heap"},
        {Opt_user_xattr, "user_xattr"},
        {Opt_nouser_xattr, "nouser_xattr"},
@@ -426,6 +428,8 @@ static int parse_options(struct super_block *sb, char *options)
                                        "the device does not support discard");
                        }
                        break;
+               case Opt_nodiscard:
+                       clear_opt(sbi, DISCARD);
                case Opt_noheap:
                        set_opt(sbi, NOHEAP);
                        break;