fuse: add atomic open+truncate support
This patch allows fuse filesystems to implement open(..., O_TRUNC) as a single
request, instead of separate truncate and open requests.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 6ef3973..3c13981 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -531,6 +531,8 @@
fc->async_read = 1;
if (!(arg->flags & FUSE_POSIX_LOCKS))
fc->no_lock = 1;
+ if (arg->flags & FUSE_ATOMIC_O_TRUNC)
+ fc->atomic_o_trunc = 1;
} else {
ra_pages = fc->max_read / PAGE_CACHE_SIZE;
fc->no_lock = 1;
@@ -553,7 +555,8 @@
arg->major = FUSE_KERNEL_VERSION;
arg->minor = FUSE_KERNEL_MINOR_VERSION;
arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
- arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_FILE_OPS;
+ arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_FILE_OPS |
+ FUSE_ATOMIC_O_TRUNC;
req->in.h.opcode = FUSE_INIT;
req->in.numargs = 1;
req->in.args[0].size = sizeof(*arg);