[PATCH] FUSE: add access call
Add a new access call, which will only be called if ->permission is invoked
from sys_access(). In all other cases permission checking is delayed until
the actual filesystem operation.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 61b58fd..4bc1afc 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -461,6 +461,38 @@
return fuse_do_getattr(inode);
}
+static int fuse_access(struct inode *inode, int mask)
+{
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ struct fuse_req *req;
+ struct fuse_access_in inarg;
+ int err;
+
+ if (fc->no_access)
+ return 0;
+
+ req = fuse_get_request(fc);
+ if (!req)
+ return -EINTR;
+
+ memset(&inarg, 0, sizeof(inarg));
+ inarg.mask = mask;
+ req->in.h.opcode = FUSE_ACCESS;
+ req->in.h.nodeid = get_node_id(inode);
+ req->inode = inode;
+ req->in.numargs = 1;
+ req->in.args[0].size = sizeof(inarg);
+ req->in.args[0].value = &inarg;
+ request_send(fc, req);
+ err = req->out.h.error;
+ fuse_put_request(fc, req);
+ if (err == -ENOSYS) {
+ fc->no_access = 1;
+ err = 0;
+ }
+ return err;
+}
+
static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd)
{
struct fuse_conn *fc = get_fuse_conn(inode);
@@ -493,6 +525,9 @@
int mode = inode->i_mode;
if ((mask & MAY_EXEC) && !S_ISDIR(mode) && !(mode & S_IXUGO))
return -EACCES;
+
+ if (nd && (nd->flags & LOOKUP_ACCESS))
+ return fuse_access(inode, mask);
return 0;
}
}
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 5cb456f5..c4e8c3b 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -266,6 +266,9 @@
/** Is removexattr not implemented by fs? */
unsigned no_removexattr : 1;
+ /** Is access not implemented by fs? */
+ unsigned no_access : 1;
+
/** Backing dev info */
struct backing_dev_info bdi;
};
diff --git a/include/linux/fuse.h b/include/linux/fuse.h
index 6e91c9a..507913b 100644
--- a/include/linux/fuse.h
+++ b/include/linux/fuse.h
@@ -99,7 +99,8 @@
FUSE_OPENDIR = 27,
FUSE_READDIR = 28,
FUSE_RELEASEDIR = 29,
- FUSE_FSYNCDIR = 30
+ FUSE_FSYNCDIR = 30,
+ FUSE_ACCESS = 34
};
/* Conservative buffer size for the client */
@@ -222,6 +223,11 @@
__u32 padding;
};
+struct fuse_access_in {
+ __u32 mask;
+ __u32 padding;
+};
+
struct fuse_init_in_out {
__u32 major;
__u32 minor;
