From: Domenico Andreoli <domenico.andreoli@linux.com>
To: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>,
Linux PM <linux-pm@vger.kernel.org>,
Linux Memory Management List <linux-mm@kvack.org>,
linux-fsdevel@vger.kernel.org, mkleinsoft@gmail.com,
Christoph Hellwig <hch@lst.de>,
Andrew Morton <akpm@linux-foundation.org>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Len Brown <len.brown@intel.com>, Pavel Machek <pavel@ucw.cz>
Subject: [PATCH v2] hibernate: Allow uswsusp to write to swap
Date: Wed, 4 Mar 2020 18:06:46 +0100 [thread overview]
Message-ID: <20200304170646.GA31552@dumbo> (raw)
From: Domenico Andreoli <domenico.andreoli@linux.com>
It turns out that there is one use case for programs being able to
write to swap devices, and that is the userspace hibernation code.
Quick fix: disable the S_SWAPFILE check if hibernation is configured.
Fixes: dc617f29dbe5 ("vfs: don't allow writes to swap files")
Reported-by: Domenico Andreoli <domenico.andreoli@linux.com>
Reported-by: Marian Klein <mkleinsoft@gmail.com>
Signed-off-by: Domenico Andreoli <domenico.andreoli@linux.com>
v2:
- use hibernation_available() instead of IS_ENABLED(CONFIG_HIBERNATE)
- make Fixes: point to the right commit
---
fs/block_dev.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
Index: b/fs/block_dev.c
===================================================================
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -34,6 +34,7 @@
#include <linux/task_io_accounting_ops.h>
#include <linux/falloc.h>
#include <linux/uaccess.h>
+#include <linux/suspend.h>
#include "internal.h"
struct bdev_inode {
@@ -2001,7 +2002,8 @@ ssize_t blkdev_write_iter(struct kiocb *
if (bdev_read_only(I_BDEV(bd_inode)))
return -EPERM;
- if (IS_SWAPFILE(bd_inode))
+ /* uswsusp needs write permission to the swap */
+ if (IS_SWAPFILE(bd_inode) && !hibernation_available())
return -ETXTBSY;
if (!iov_iter_count(from))
next reply other threads:[~2020-03-04 17:06 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-04 17:06 Domenico Andreoli [this message]
2020-03-22 7:14 ` [PATCH v2] hibernate: Allow uswsusp to write to swap Rafael J. Wysocki
2020-03-22 11:23 ` Domenico Andreoli
2020-03-23 15:21 ` Darrick J. Wong
2020-03-24 2:19 ` Andrew Morton
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