From 4b19de6d1cb07c8bcb6778e771f9cfd5bcfdfd3e Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Thu, 2 Oct 2008 14:50:16 -0700 Subject: mm: tiny-shmem nommu fix The previous patch db203d53d474aa068984e409d807628f5841da1b ("mm: tiny-shmem fix lock ordering: mmap_sem vs i_mutex") to fix the lock ordering in tiny-shmem breaks shared anonymous and IPC memory on NOMMU architectures because it was using the expanding truncate to signal ramfs to allocate a physically contiguous RAM backing the inode (otherwise it is unusable for "memory mapping" it to userspace). However do_truncate is what caused the lock ordering error, due to it taking i_mutex. In this case, we can actually just call ramfs directly to allocate memory for the mapping, rather than go via truncate. Acked-by: David Howells Acked-by: Hugh Dickins Signed-off-by: Nick Piggin Cc: Matt Mackall Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/ramfs.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/ramfs.h b/include/linux/ramfs.h index b160fb18e8d..37aaf2b3986 100644 --- a/include/linux/ramfs.h +++ b/include/linux/ramfs.h @@ -6,6 +6,7 @@ extern int ramfs_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *data, struct vfsmount *mnt); #ifndef CONFIG_MMU +extern int ramfs_nommu_expand_for_mapping(struct inode *inode, size_t newsize); extern unsigned long ramfs_nommu_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, -- cgit v1.2.3