sys_swapon: use a single error label (bd69010b) · Commits · 戴 / test

sys_swapon currently has two error labels, bad_swap and bad_swap_2. bad_swap does the same as bad_swap_2 plus destroy_swap_extents() and swap_cgroup_swapoff(); both are noops in the places where bad_swap_2 is jumped to. With a single extra test for inode (matching the one in the S_ISREG case below), all the error paths in the function can go to bad_swap. Signed-off-by:

Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by:

Eric B Munson <emunson@mgebm.net> Acked-by:

Eric B Munson <emunson@mgebm.net> Reviewed-by:

KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

mm/swapfile.c

+3 −4

Original line number	Diff line number	Diff line
		@@ -1918,13 +1918,13 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
		if (IS_ERR(name)) {
		error = PTR_ERR(name);
		name = NULL;
		goto bad_swap_2;
		goto bad_swap;
		}
		swap_file = filp_open(name, O_RDWR\|O_LARGEFILE, 0);
		if (IS_ERR(swap_file)) {
		error = PTR_ERR(swap_file);
		swap_file = NULL;
		goto bad_swap_2;
		goto bad_swap;
		}

		p->swap_file = swap_file;
		@@ -2141,13 +2141,12 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
		error = 0;
		goto out;
		bad_swap:
		if (S_ISBLK(inode->i_mode) && p->bdev) {
		if (inode && S_ISBLK(inode->i_mode) && p->bdev) {
		set_blocksize(p->bdev, p->old_block_size);
		blkdev_put(p->bdev, FMODE_READ \| FMODE_WRITE \| FMODE_EXCL);
		}
		destroy_swap_extents(p);
		swap_cgroup_swapoff(p->type);
		bad_swap_2:
		spin_lock(&swap_lock);
		p->swap_file = NULL;
		p->flags = 0;

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