fat: make discard a mount option
Currently shipping discard capable SSDs and arrays have rather sub-optimal
implementations of the command and can the use of it can cause massive
slowdowns. Make issueing these commands option as it's already in btrfs
and gfs2.
Signed-off-by: Christoph Hellwig <hch@lst.de>
[hirofumi@mail.parknet.co.jp: tweaks, and add "discard" to fat_show_options]
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 76b7961..14da530 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -858,6 +858,8 @@
seq_puts(m, ",errors=panic");
else
seq_puts(m, ",errors=remount-ro");
+ if (opts->discard)
+ seq_puts(m, ",discard");
return 0;
}
@@ -871,7 +873,7 @@
Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
Opt_obsolate, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
- Opt_err_panic, Opt_err_ro, Opt_err,
+ Opt_err_panic, Opt_err_ro, Opt_discard, Opt_err,
};
static const match_table_t fat_tokens = {
@@ -899,6 +901,7 @@
{Opt_err_cont, "errors=continue"},
{Opt_err_panic, "errors=panic"},
{Opt_err_ro, "errors=remount-ro"},
+ {Opt_discard, "discard"},
{Opt_obsolate, "conv=binary"},
{Opt_obsolate, "conv=text"},
{Opt_obsolate, "conv=auto"},
@@ -1136,6 +1139,9 @@
case Opt_rodir:
opts->rodir = 1;
break;
+ case Opt_discard:
+ opts->discard = 1;
+ break;
/* obsolete mount options */
case Opt_obsolate: