From ef83b6e8f40bb24b92ad73b5889732346e54a793 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 29 Sep 2015 15:48:11 -0400 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: Cc: "Theodore Ts'o" Cc: Matthew Wilcox Cc: linux-ext4@vger.kernel.org Cc: Kirill A. Shutemov Reported-by: Dave Chinner Acked-by: Jan Kara Signed-off-by: Dan Williams --- 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 3a71cea68420..748d35afc902 100644 --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -569,6 +569,8 @@ 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 753f4e68b820..c9ab67da6e5a 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1664,8 +1664,12 @@ 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