From 56939e014a6c212b317414faa307029e2e80c3b9 Mon Sep 17 00:00:00 2001 From: Domenico Andreoli Date: Mon, 23 Mar 2020 08:22:15 -0700 Subject: hibernate: Allow uswsusp to write to swap 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 Reported-by: Marian Klein Signed-off-by: Domenico Andreoli Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/block_dev.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'fs/block_dev.c') diff --git a/fs/block_dev.c b/fs/block_dev.c index 69bf2fb6f7cd..84fe0162ff13 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -34,6 +34,7 @@ #include #include #include +#include #include "internal.h" struct bdev_inode { @@ -2001,7 +2002,8 @@ ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) 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)) -- cgit v1.2.3