[PATCH] fuse: add DESTROY operation
Add a DESTROY operation for block device based filesystems. With the help of
this operation, such a filesystem can flush dirty data to the device
synchronously before the umount returns.
This is needed in situations where the filesystem is assumed to be clean
immediately after unmount (e.g. ejecting removable media).
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/fuse_i.h b/fs/fuse/fuse_i.h
index 58d482d..b98b20d 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -298,6 +298,9 @@
reply, before any other request, and never cleared */
unsigned conn_error : 1;
+ /** Connection successful. Only set in INIT */
+ unsigned conn_init : 1;
+
/** Do readpages asynchronously? Only set in INIT */
unsigned async_read : 1;
@@ -368,6 +371,9 @@
/** Key for lock owner ID scrambling */
u32 scramble_key[4];
+
+ /** Reserved request for the DESTROY message */
+ struct fuse_req *destroy_req;
};
static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 1baaaeb2..437d61c 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -206,10 +206,23 @@
fuse_abort_conn(get_fuse_conn_super(vfsmnt->mnt_sb));
}
+static void fuse_send_destroy(struct fuse_conn *fc)
+{
+ struct fuse_req *req = fc->destroy_req;
+ if (req && fc->conn_init) {
+ fc->destroy_req = NULL;
+ req->in.h.opcode = FUSE_DESTROY;
+ req->force = 1;
+ request_send(fc, req);
+ fuse_put_request(fc, req);
+ }
+}
+
static void fuse_put_super(struct super_block *sb)
{
struct fuse_conn *fc = get_fuse_conn_super(sb);
+ fuse_send_destroy(fc);
spin_lock(&fc->lock);
fc->connected = 0;
fc->blocked = 0;
@@ -410,6 +423,8 @@
void fuse_conn_put(struct fuse_conn *fc)
{
if (atomic_dec_and_test(&fc->count)) {
+ if (fc->destroy_req)
+ fuse_request_free(fc->destroy_req);
mutex_destroy(&fc->inst_mutex);
kfree(fc);
}
@@ -466,6 +481,7 @@
fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
fc->minor = arg->minor;
fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
+ fc->conn_init = 1;
}
fuse_put_request(fc, req);
fc->blocked = 0;
@@ -563,6 +579,12 @@
if (!init_req)
goto err_put_root;
+ if (is_bdev) {
+ fc->destroy_req = fuse_request_alloc();
+ if (!fc->destroy_req)
+ goto err_put_root;
+ }
+
mutex_lock(&fuse_mutex);
err = -EINVAL;
if (file->private_data)
diff --git a/include/linux/fuse.h b/include/linux/fuse.h
index 162a754..534744e 100644
--- a/include/linux/fuse.h
+++ b/include/linux/fuse.h
@@ -133,6 +133,7 @@
FUSE_CREATE = 35,
FUSE_INTERRUPT = 36,
FUSE_BMAP = 37,
+ FUSE_DESTROY = 38,
};
/* The read buffer is required to be at least 8k, but may be much larger */