Commit b4b5798c authored Dec 21, 2017 by Dan Williams

ext2: auto disable dax instead of failing mount



Bring the ext2 filesystem in line with xfs that only warns and continues
when the "-o dax" option is specified to mount and the backing device
does not support dax. This is in preparation for removing dax support
from devices that do not enable get_user_pages() operations on dax
mappings. In other words 'gup' support is required and configurations
that were using so called 'page-less' dax will be converted back to
using the page cache.

Removing the broken 'page-less' dax support is a pre-requisite for
removing the "EXPERIMENTAL" warning when mounting a filesystem in dax
mode.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

parent 24f3478d

fs/ext2/super.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -959,8 +959,11 @@ static int ext2_fill_super(struct super_block sb, void data, int silent)

		if (sbi->s_mount_opt & EXT2_MOUNT_DAX) {
		err = bdev_dax_supported(sb, blocksize);
		if (err)
		goto failed_mount;
		if (err) {
		ext2_msg(sb, KERN_ERR,
		"DAX unsupported by block device. Turning off DAX.");
		sbi->s_mount_opt &= ~EXT2_MOUNT_DAX;
		}
		}

		/* If the blocksize doesn't match, re-read the thing.. */

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