Messages in this thread Patch in this message | | | Subject | [patch 2/3] fuse: allow private mappings of "direct_io" files | From | Miklos Szeredi <> | Date | Mon, 30 Mar 2009 22:03:11 +0200 |
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From: Miklos Szeredi <mszeredi@suse.cz>
Allow MAP_PRIVATE mmaps of "direct_io" files. This is necessary for execute support.
MAP_SHARED mappings require some sort of coherency between the underlying file and the mapping. With "direct_io" it is difficult to provide this, so for the moment just disallow shared (read-write and read-only) mappings altogether.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> --- fs/fuse/file.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
Index: linux-2.6/fs/fuse/file.c =================================================================== --- linux-2.6.orig/fs/fuse/file.c 2009-03-30 18:47:55.000000000 +0200 +++ linux-2.6/fs/fuse/file.c 2009-03-30 19:07:11.000000000 +0200 @@ -1291,6 +1291,15 @@ static int fuse_file_mmap(struct file *f return 0; } +static int fuse_direct_mmap(struct file *file, struct vm_area_struct *vma) +{ + /* Can't provide the coherency needed for MAP_SHARED */ + if (vma->vm_flags & VM_MAYSHARE) + return -ENODEV; + + return generic_file_mmap(file, vma); +} + static int convert_fuse_file_lock(const struct fuse_file_lock *ffl, struct file_lock *fl) { @@ -1925,6 +1934,7 @@ static const struct file_operations fuse .llseek = fuse_file_llseek, .read = fuse_direct_read, .write = fuse_direct_write, + .mmap = fuse_direct_mmap, .open = fuse_open, .flush = fuse_flush, .release = fuse_release, @@ -1934,7 +1944,7 @@ static const struct file_operations fuse .unlocked_ioctl = fuse_file_ioctl, .compat_ioctl = fuse_file_compat_ioctl, .poll = fuse_file_poll, - /* no mmap and splice_read */ + /* no splice_read */ }; static const struct address_space_operations fuse_file_aops = {
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