Merge tag 'pull-set_blocksize' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs blocksize updates from Al Viro:
 "This gets rid of bogus set_blocksize() uses, switches it over
  to be based on a 'struct file *' and verifies that the caller
  has the device opened exclusively"

* tag 'pull-set_blocksize' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  make set_blocksize() fail unless block device is opened exclusive
  set_blocksize(): switch to passing struct file *
  btrfs_get_bdev_and_sb(): call set_blocksize() only for exclusive opens
  swsusp: don't bother with setting block size
  zram: don't bother with reopening - just use O_EXCL for open
  swapon(2): open swap with O_EXCL
  swapon(2)/swapoff(2): don't bother with block size
  pktcdvd: sort set_blocksize() calls out
  bcache_register(): don't bother with set_blocksize()

1 files changed, 2 insertions, 27 deletions

diff --git a/mm/swapfile.c b/mm/swapfile.c
index f6ca215fb92f..b3e5e384e330 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -2469,7 +2469,6 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
 	struct inode *inode;
 	struct filename *pathname;
 	int err, found = 0;
-	unsigned int old_block_size;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
@@ -2582,7 +2581,6 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
 	}
 
 	swap_file = p->swap_file;
-	old_block_size = p->old_block_size;
 	p->swap_file = NULL;
 	p->max = 0;
 	swap_map = p->swap_map;
@@ -2605,11 +2603,6 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
 	exit_swap_address_space(p->type);
 
 	inode = mapping->host;
-	if (p->bdev_file) {
-		set_blocksize(p->bdev, old_block_size);
-		fput(p->bdev_file);
-		p->bdev_file = NULL;
-	}
 
 	inode_lock(inode);
 	inode->i_flags &= ~S_SWAPFILE;
@@ -2835,21 +2828,8 @@ static struct swap_info_struct *alloc_swap_info(void)
 
 static int claim_swapfile(struct swap_info_struct *p, struct inode *inode)
 {
-	int error;
-
 	if (S_ISBLK(inode->i_mode)) {
-		p->bdev_file = bdev_file_open_by_dev(inode->i_rdev,
-				BLK_OPEN_READ | BLK_OPEN_WRITE, p, NULL);
-		if (IS_ERR(p->bdev_file)) {
-			error = PTR_ERR(p->bdev_file);
-			p->bdev_file = NULL;
-			return error;
-		}
-		p->bdev = file_bdev(p->bdev_file);
-		p->old_block_size = block_size(p->bdev);
-		error = set_blocksize(p->bdev, PAGE_SIZE);
-		if (error < 0)
-			return error;
+		p->bdev = I_BDEV(inode);
 		/*
 		 * Zoned block devices contain zones that have a sequential
 		 * write only restriction.  Hence zoned block devices are not
@@ -3090,7 +3070,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 		name = NULL;
 		goto bad_swap;
 	}
-	swap_file = file_open_name(name, O_RDWR|O_LARGEFILE, 0);
+	swap_file = file_open_name(name, O_RDWR | O_LARGEFILE | O_EXCL, 0);
 	if (IS_ERR(swap_file)) {
 		error = PTR_ERR(swap_file);
 		swap_file = NULL;
@@ -3289,11 +3269,6 @@ bad_swap:
 	p->percpu_cluster = NULL;
 	free_percpu(p->cluster_next_cpu);
 	p->cluster_next_cpu = NULL;
-	if (p->bdev_file) {
-		set_blocksize(p->bdev, p->old_block_size);
-		fput(p->bdev_file);
-		p->bdev_file = NULL;
-	}
 	inode = NULL;
 	destroy_swap_extents(p);
 	swap_cgroup_swapoff(p->type);