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/fatent.c b/fs/fat/fatent.c
index a810377..81184d3 100644
--- a/fs/fat/fatent.c
+++ b/fs/fat/fatent.c
@@ -566,16 +566,21 @@
goto error;
}
- /*
- * Issue discard for the sectors we no longer care about,
- * batching contiguous clusters into one request
- */
- if (cluster != fatent.entry + 1) {
- int nr_clus = fatent.entry - first_cl + 1;
+ if (sbi->options.discard) {
+ /*
+ * Issue discard for the sectors we no longer
+ * care about, batching contiguous clusters
+ * into one request
+ */
+ if (cluster != fatent.entry + 1) {
+ int nr_clus = fatent.entry - first_cl + 1;
- sb_issue_discard(sb, fat_clus_to_blknr(sbi, first_cl),
- nr_clus * sbi->sec_per_clus);
- first_cl = cluster;
+ sb_issue_discard(sb,
+ fat_clus_to_blknr(sbi, first_cl),
+ nr_clus * sbi->sec_per_clus);
+
+ first_cl = cluster;
+ }
}
ops->ent_put(&fatent, FAT_ENT_FREE);