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-next>] [day] [month] [year] [list]
Message-ID: <20150929194806.5276.863.stgit@dwillia2-desk3.jf.intel.com>
Date:	Tue, 29 Sep 2015 15:48:11 -0400
From:	Dan Williams <dan.j.williams@...el.com>
To:	ross.zwisler@...ux.intel.com, david@...morbit.com
Cc:	Theodore Ts'o <tytso@....edu>, linux-nvdimm@...ts.01.org,
	Andreas Dilger <adilger.kernel@...ger.ca>,
	Jan Kara <jack@...e.com>, linux-fsdevel@...r.kernel.org,
	Matthew Wilcox <willy@...ux.intel.com>,
	linux-ext4@...r.kernel.org,
	"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
Subject: [PATCH] ext2, ext4: warn when mounting with dax enabled

Similar to XFS warn when mounting DAX while it is still considered under
development.  Also, aspects of the DAX implementation, for example
synchronization against multiple faults and faults causing block
allocation, depend on the correct implementation in the filesystem.  The
maturity of a given DAX implementation is filesystem specific.

Cc: Jan Kara <jack@...e.com>
Cc: "Theodore Ts'o" <tytso@....edu>
Cc: Andreas Dilger <adilger.kernel@...ger.ca>
Cc: Matthew Wilcox <willy@...ux.intel.com>
Cc: linux-ext4@...r.kernel.org
Cc: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
Reported-by: Dave Chinner <david@...morbit.com>
Signed-off-by: Dan Williams <dan.j.williams@...el.com>
---
Given the pending investigations [1], and rather than marking FS_DAX
broken, warn about DAX usage until we've landed fixes for the issues
that Dave has identified.

[1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002266.html

 fs/ext2/super.c |    2 ++
 fs/ext4/super.c |    6 +++++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 900e19cf9ef6..2597b0663bf2 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -566,6 +566,8 @@ static int parse_options(char *options, struct super_block *sb)
 			/* Fall through */
 		case Opt_dax:
 #ifdef CONFIG_FS_DAX
+			ext2_msg(sb, KERN_WARNING,
+		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
 			set_opt(sbi->s_mount_opt, DAX);
 #else
 			ext2_msg(sb, KERN_INFO, "dax option not supported");
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index a63c7b0a10cf..4db6eb0b6979 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1656,8 +1656,12 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
 		}
 		sbi->s_jquota_fmt = m->mount_opt;
 #endif
-#ifndef CONFIG_FS_DAX
 	} else if (token == Opt_dax) {
+#ifdef CONFIG_FS_DAX
+		ext4_msg(sb, KERN_WARNING,
+		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
+			sbi->s_mount_opt |= m->mount_opt;
+#else
 		ext4_msg(sb, KERN_INFO, "dax option not supported");
 		return -1;
 #endif

--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Powered by blists - more mailing lists