Re: [PATCH] Fix races in 2.4.2-ac22 SysV shared memory

[Linus Torvalds]

On Fri, 23 Mar 2001, Stephen C. Tweedie wrote:
>
> The patch below is for two races in sysV shared memory.

	+       spin_lock (&info->lock);
	+
	+       /* The shmem_swp_entry() call may have blocked, and
	+        * shmem_writepage may have been moving a page between the page
	+        * cache and swap cache.  We need to recheck the page cache
	+        * under the protection of the info->lock spinlock. */
	+
	+       page = find_lock_page(mapping, idx);

Ehh.. Sleeping with the spin-lock held? Sounds like a truly bad idea.

		Linus