[PATCH] FUSE - mount options
This patch adds miscellaneous mount options to the FUSE filesystem.
The following mount options are added:
o default_permissions: check permissions with generic_permission()
o allow_other: allow other users to access files
o allow_root: allow root to access files
o kernel_cache: don't invalidate page cache on open
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 8adc1ee..0950455 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -418,7 +418,8 @@
struct fuse_conn *fc = get_fuse_conn(inode);
if (get_node_id(inode) == FUSE_ROOT_ID) {
- if (current->fsuid != fc->user_id)
+ if (!(fc->flags & FUSE_ALLOW_OTHER) &&
+ current->fsuid != fc->user_id)
return -EACCES;
} else if (time_before_eq(jiffies, fi->i_time))
return 0;
@@ -430,9 +431,31 @@
{
struct fuse_conn *fc = get_fuse_conn(inode);
- if (current->fsuid != fc->user_id)
+ if (!(fc->flags & FUSE_ALLOW_OTHER) && current->fsuid != fc->user_id)
return -EACCES;
- else {
+ else if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
+ int err = generic_permission(inode, mask, NULL);
+
+ /* If permission is denied, try to refresh file
+ attributes. This is also needed, because the root
+ node will at first have no permissions */
+ if (err == -EACCES) {
+ err = fuse_do_getattr(inode);
+ if (!err)
+ err = generic_permission(inode, mask, NULL);
+ }
+
+ /* FIXME: Need some mechanism to revoke permissions:
+ currently if the filesystem suddenly changes the
+ file mode, we will not be informed about it, and
+ continue to allow access to the file/directory.
+
+ This is actually not so grave, since the user can
+ simply keep access to the file/directory anyway by
+ keeping it open... */
+
+ return err;
+ } else {
int mode = inode->i_mode;
if ((mask & MAY_WRITE) && IS_RDONLY(inode) &&
(S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
@@ -636,6 +659,12 @@
int err;
int is_truncate = 0;
+ if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
+ err = inode_change_ok(inode, attr);
+ if (err)
+ return err;
+ }
+
if (attr->ia_valid & ATTR_SIZE) {
unsigned long limit;
is_truncate = 1;