From 681142f9211b23e6aa2984259d38b76d7bdc05a8 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Sat, 21 Nov 2009 20:28:52 +0900
Subject: 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>
---
fs/fat/fatent.c | 25 +++++++++++++++----------
1 file changed, 15 insertions(+), 10 deletions(-)
(limited to 'fs/fat/fatent.c')
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 @@ int fat_free_clusters(struct inode *inode, int cluster)
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;
-
- sb_issue_discard(sb, fat_clus_to_blknr(sbi, first_cl),
- nr_clus * sbi->sec_per_clus);
- first_cl = cluster;
+ 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;
+ }
}
ops->ent_put(&fatent, FAT_ENT_FREE);
--
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