diff mbox series

[016/158] mm, swap: disallow swapon() on zoned block devices

Message ID 20191201014956.tXC37Qp6P%akpm@linux-foundation.org (mailing list archive)
State New, archived
Headers show
Series [001/158] scripts/spelling.txt: add more spellings to spelling.txt | expand

Commit Message

Andrew Morton Dec. 1, 2019, 1:49 a.m. UTC
From: Naohiro Aota <naohiro.aota@wdc.com>
Subject: mm, swap: disallow swapon() on zoned block devices

A zoned block device consists of a number of zones.  Zones are either
conventional and accepting random writes or sequential and requiring that
writes be issued in LBA order from each zone write pointer position.  For
the write restriction, zoned block devices are not suitable for a swap
device.  Disallow swapon on them.

[akpm@linux-foundation.org: reflow and reword comment, per Christoph]
Link: http://lkml.kernel.org/r/20191015085814.637837-1-naohiro.aota@wdc.com
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Theodore Y. Ts'o" <tytso@mit.edu>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/swapfile.c |    7 +++++++
 1 file changed, 7 insertions(+)
diff mbox series

Patch

--- a/mm/swapfile.c~mm-swap-disallow-swapon-on-zoned-block-devices
+++ a/mm/swapfile.c
@@ -2887,6 +2887,13 @@  static int claim_swapfile(struct swap_in
 		error = set_blocksize(p->bdev, PAGE_SIZE);
 		if (error < 0)
 			return error;
+		/*
+		 * Zoned block devices contain zones that have a sequential
+		 * write only restriction.  Hence zoned block devices are not
+		 * suitable for swapping.  Disallow them here.
+		 */
+		if (blk_queue_is_zoned(p->bdev->bd_queue))
+			return -EINVAL;
 		p->flags |= SWP_BLKDEV;
 	} else if (S_ISREG(inode->i_mode)) {
 		p->bdev = inode->i_sb->s_bdev;