Fixes for 4.19

[thirdparty/kernel/stable-queue.git] / releases / 3.6.8 / reiserfs-protect-reiserfs_quota_on-with-write-lock.patch

From b9e06ef2e8706fe669b51f4364e3aeed58639eb2 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Tue, 13 Nov 2012 16:34:17 +0100
Subject: reiserfs: Protect reiserfs_quota_on() with write lock

From: Jan Kara <jack@suse.cz>

commit b9e06ef2e8706fe669b51f4364e3aeed58639eb2 upstream.

In reiserfs_quota_on() we do quite some work - for example unpacking
tail of a quota file. Thus we have to hold write lock until a moment
we call back into the quota code.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/reiserfs/super.c |   11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

--- a/fs/reiserfs/super.c
+++ b/fs/reiserfs/super.c
@@ -2211,8 +2211,11 @@ static int reiserfs_quota_on(struct supe
 	struct reiserfs_transaction_handle th;
 	int opt = type == USRQUOTA ? REISERFS_USRQUOTA : REISERFS_GRPQUOTA;
 
-	if (!(REISERFS_SB(sb)->s_mount_opt & (1 << opt)))
-		return -EINVAL;
+	reiserfs_write_lock(sb);
+	if (!(REISERFS_SB(sb)->s_mount_opt & (1 << opt))) {
+		err = -EINVAL;
+		goto out;
+	}
 
 	/* Quotafile not on the same filesystem? */
 	if (path->dentry->d_sb != sb) {
@@ -2254,8 +2257,10 @@ static int reiserfs_quota_on(struct supe
 		if (err)
 			goto out;
 	}
-	err = dquot_quota_on(sb, type, format_id, path);
+	reiserfs_write_unlock(sb);
+	return dquot_quota_on(sb, type, format_id, path);
 out:
+	reiserfs_write_unlock(sb);
 	return err;
 }