From b4caecd48005fbed3949dde6c1cb233142fd69e9 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 14 Jan 2015 10:42:32 +0100 Subject: fs: introduce f_op->mmap_capabilities for nommu mmap support Since "BDI: Provide backing device capability information [try #3]" the backing_dev_info structure also provides flags for the kind of mmap operation available in a nommu environment, which is entirely unrelated to it's original purpose. Introduce a new nommu-only file operation to provide this information to the nommu mmap code instead. Splitting this from the backing_dev_info structure allows to remove lots of backing_dev_info instance that aren't otherwise needed, and entirely gets rid of the concept of providing a backing_dev_info for a character device. It also removes the need for the mtd_inodefs filesystem. Signed-off-by: Christoph Hellwig Reviewed-by: Tejun Heo Acked-by: Brian Norris Signed-off-by: Jens Axboe --- fs/ramfs/file-nommu.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'fs/ramfs/file-nommu.c') diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c index bbafbde3471a..f6ab41b39612 100644 --- a/fs/ramfs/file-nommu.c +++ b/fs/ramfs/file-nommu.c @@ -34,7 +34,14 @@ static unsigned long ramfs_nommu_get_unmapped_area(struct file *file, unsigned long flags); static int ramfs_nommu_mmap(struct file *file, struct vm_area_struct *vma); +static unsigned ramfs_mmap_capabilities(struct file *file) +{ + return NOMMU_MAP_DIRECT | NOMMU_MAP_COPY | NOMMU_MAP_READ | + NOMMU_MAP_WRITE | NOMMU_MAP_EXEC; +} + const struct file_operations ramfs_file_operations = { + .mmap_capabilities = ramfs_mmap_capabilities, .mmap = ramfs_nommu_mmap, .get_unmapped_area = ramfs_nommu_get_unmapped_area, .read = new_sync_read, -- cgit v1.2.3-59-g8ed1b