linux-kernel - [34-longterm 011/260] ext4: stop issuing discards if not supported by device

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1293952756-15010-12-git-send-email-paul.gortmaker@windriver.com>
Date:	Sun,  2 Jan 2011 02:15:07 -0500
From:	Paul Gortmaker <paul.gortmaker@...driver.com>
To:	stable@...nel.org, linux-kernel@...r.kernel.org
Cc:	stable-review@...nel.org, Eric Sandeen <sandeen@...hat.com>,
	"Theodore Ts'o" <tytso@....edu>,
	Paul Gortmaker <paul.gortmaker@...driver.com>
Subject: [34-longterm 011/260] ext4: stop issuing discards if not supported by device

From: Eric Sandeen <sandeen@...hat.com>

commit a30eec2a8650a77f754e84b2e15f062fe652baa7 upstream.

Turn off issuance of discard requests if the device does
not support it - similar to the action we take for barriers.
This will save a little computation time if a non-discardable
device is mounted with -o discard, and also makes it obvious
that it's not doing what was asked at mount time ...

Signed-off-by: Eric Sandeen <sandeen@...hat.com>
Signed-off-by: "Theodore Ts'o" <tytso@....edu>
Signed-off-by: Paul Gortmaker <paul.gortmaker@...driver.com>
---
 fs/ext4/mballoc.c |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 8639d5a6..4f2d3a9 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2534,6 +2534,7 @@ static void release_blocks_on_commit(journal_t *journal, transaction_t *txn)
 			 entry->count, entry->group, entry);
 
 		if (test_opt(sb, DISCARD)) {
+			int ret;
 			ext4_fsblk_t discard_block;
 
 			discard_block = entry->start_blk +
@@ -2541,7 +2542,12 @@ static void release_blocks_on_commit(journal_t *journal, transaction_t *txn)
 			trace_ext4_discard_blocks(sb,
 					(unsigned long long)discard_block,
 					entry->count);
-			sb_issue_discard(sb, discard_block, entry->count);
+			ret = sb_issue_discard(sb, discard_block, entry->count);
+			if (ret == EOPNOTSUPP) {
+				ext4_warning(sb,
+					"discard not supported, disabling");
+				clear_opt(EXT4_SB(sb)->s_mount_opt, DISCARD);
+			}
 		}
 
 		err = ext4_mb_load_buddy(sb, entry->group, &e4b);
-- 
1.7.3.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/