[PATCH] fuse: add control filesystem
[linux-block.git] / fs / fuse / inode.c
index 7627022446b27b0cd067006df2b818dc1b5d9bf5..13a7e8ab7a78259c132b3df8882ac0d0087b5d87 100644 (file)
@@ -11,7 +11,6 @@
 #include <linux/pagemap.h>
 #include <linux/slab.h>
 #include <linux/file.h>
-#include <linux/mount.h>
 #include <linux/seq_file.h>
 #include <linux/init.h>
 #include <linux/module.h>
@@ -23,13 +22,8 @@ MODULE_DESCRIPTION("Filesystem in Userspace");
 MODULE_LICENSE("GPL");
 
 static kmem_cache_t *fuse_inode_cachep;
-static struct subsystem connections_subsys;
-
-struct fuse_conn_attr {
-       struct attribute attr;
-       ssize_t (*show)(struct fuse_conn *, char *);
-       ssize_t (*store)(struct fuse_conn *, const char *, size_t);
-};
+struct list_head fuse_conn_list;
+DEFINE_MUTEX(fuse_mutex);
 
 #define FUSE_SUPER_MAGIC 0x65735546
 
@@ -204,22 +198,19 @@ static void fuse_put_super(struct super_block *sb)
 {
        struct fuse_conn *fc = get_fuse_conn_super(sb);
 
-       down_write(&fc->sbput_sem);
-       while (!list_empty(&fc->background))
-               fuse_release_background(fc,
-                                       list_entry(fc->background.next,
-                                                  struct fuse_req, bg_entry));
-
        spin_lock(&fc->lock);
-       fc->mounted = 0;
        fc->connected = 0;
+       fc->blocked = 0;
        spin_unlock(&fc->lock);
-       up_write(&fc->sbput_sem);
        /* Flush all readers on this fs */
        kill_fasync(&fc->fasync, SIGIO, POLL_IN);
        wake_up_all(&fc->waitq);
-       kobject_del(&fc->kobj);
-       kobject_put(&fc->kobj);
+       wake_up_all(&fc->blocked_waitq);
+       mutex_lock(&fuse_mutex);
+       list_del(&fc->entry);
+       fuse_ctl_remove_conn(fc);
+       mutex_unlock(&fuse_mutex);
+       fuse_conn_put(fc);
 }
 
 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
@@ -236,8 +227,9 @@ static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr
        /* fsid is left zero */
 }
 
-static int fuse_statfs(struct super_block *sb, struct kstatfs *buf)
+static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
 {
+       struct super_block *sb = dentry->d_sb;
        struct fuse_conn *fc = get_fuse_conn_super(sb);
        struct fuse_req *req;
        struct fuse_statfs_out outarg;
@@ -368,11 +360,6 @@ static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
        return 0;
 }
 
-static void fuse_conn_release(struct kobject *kobj)
-{
-       kfree(get_fuse_conn_kobj(kobj));
-}
-
 static struct fuse_conn *new_conn(void)
 {
        struct fuse_conn *fc;
@@ -380,15 +367,12 @@ static struct fuse_conn *new_conn(void)
        fc = kzalloc(sizeof(*fc), GFP_KERNEL);
        if (fc) {
                spin_lock_init(&fc->lock);
+               atomic_set(&fc->count, 1);
                init_waitqueue_head(&fc->waitq);
                init_waitqueue_head(&fc->blocked_waitq);
                INIT_LIST_HEAD(&fc->pending);
                INIT_LIST_HEAD(&fc->processing);
                INIT_LIST_HEAD(&fc->io);
-               INIT_LIST_HEAD(&fc->background);
-               init_rwsem(&fc->sbput_sem);
-               kobj_set_kset_s(fc, connections_subsys);
-               kobject_init(&fc->kobj);
                atomic_set(&fc->num_waiting, 0);
                fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
                fc->bdi.unplug_io_fn = default_unplug_io_fn;
@@ -398,6 +382,18 @@ static struct fuse_conn *new_conn(void)
        return fc;
 }
 
+void fuse_conn_put(struct fuse_conn *fc)
+{
+       if (atomic_dec_and_test(&fc->count))
+               kfree(fc);
+}
+
+struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
+{
+       atomic_inc(&fc->count);
+       return fc;
+}
+
 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
 {
        struct fuse_attr attr;
@@ -467,10 +463,9 @@ static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
        request_send_background(fc, req);
 }
 
-static unsigned long long conn_id(void)
+static u64 conn_id(void)
 {
-       /* BKL is held for ->get_sb() */
-       static unsigned long long ctr = 1;
+       static u64 ctr = 1;
        return ctr++;
 }
 
@@ -527,25 +522,21 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
        if (!init_req)
                goto err_put_root;
 
-       err = kobject_set_name(&fc->kobj, "%llu", conn_id());
-       if (err)
-               goto err_free_req;
-
-       err = kobject_add(&fc->kobj);
-       if (err)
-               goto err_free_req;
-
-       /* Setting file->private_data can't race with other mount()
-          instances, since BKL is held for ->get_sb() */
+       mutex_lock(&fuse_mutex);
        err = -EINVAL;
        if (file->private_data)
-               goto err_kobject_del;
+               goto err_unlock;
+
+       fc->id = conn_id();
+       err = fuse_ctl_add_conn(fc);
+       if (err)
+               goto err_unlock;
 
+       list_add_tail(&fc->entry, &fuse_conn_list);
        sb->s_root = root_dentry;
-       fc->mounted = 1;
        fc->connected = 1;
-       kobject_get(&fc->kobj);
-       file->private_data = fc;
+       file->private_data = fuse_conn_get(fc);
+       mutex_unlock(&fuse_mutex);
        /*
         * atomic_dec_and_test() in fput() provides the necessary
         * memory barrier for file->private_data to be visible on all
@@ -557,23 +548,22 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 
        return 0;
 
- err_kobject_del:
-       kobject_del(&fc->kobj);
- err_free_req:
+ err_unlock:
+       mutex_unlock(&fuse_mutex);
        fuse_request_free(init_req);
  err_put_root:
        dput(root_dentry);
  err:
        fput(file);
-       kobject_put(&fc->kobj);
+       fuse_conn_put(fc);
        return err;
 }
 
-static struct super_block *fuse_get_sb(struct file_system_type *fs_type,
-                                      int flags, const char *dev_name,
-                                      void *raw_data)
+static int fuse_get_sb(struct file_system_type *fs_type,
+                      int flags, const char *dev_name,
+                      void *raw_data, struct vfsmount *mnt)
 {
-       return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super);
+       return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
 }
 
 static struct file_system_type fuse_fs_type = {
@@ -583,68 +573,8 @@ static struct file_system_type fuse_fs_type = {
        .kill_sb        = kill_anon_super,
 };
 
-static ssize_t fuse_conn_waiting_show(struct fuse_conn *fc, char *page)
-{
-       return sprintf(page, "%i\n", atomic_read(&fc->num_waiting));
-}
-
-static ssize_t fuse_conn_abort_store(struct fuse_conn *fc, const char *page,
-                                    size_t count)
-{
-       fuse_abort_conn(fc);
-       return count;
-}
-
-static struct fuse_conn_attr fuse_conn_waiting =
-       __ATTR(waiting, 0400, fuse_conn_waiting_show, NULL);
-static struct fuse_conn_attr fuse_conn_abort =
-       __ATTR(abort, 0600, NULL, fuse_conn_abort_store);
-
-static struct attribute *fuse_conn_attrs[] = {
-       &fuse_conn_waiting.attr,
-       &fuse_conn_abort.attr,
-       NULL,
-};
-
-static ssize_t fuse_conn_attr_show(struct kobject *kobj,
-                                  struct attribute *attr,
-                                  char *page)
-{
-       struct fuse_conn_attr *fca =
-               container_of(attr, struct fuse_conn_attr, attr);
-
-       if (fca->show)
-               return fca->show(get_fuse_conn_kobj(kobj), page);
-       else
-               return -EACCES;
-}
-
-static ssize_t fuse_conn_attr_store(struct kobject *kobj,
-                                   struct attribute *attr,
-                                   const char *page, size_t count)
-{
-       struct fuse_conn_attr *fca =
-               container_of(attr, struct fuse_conn_attr, attr);
-
-       if (fca->store)
-               return fca->store(get_fuse_conn_kobj(kobj), page, count);
-       else
-               return -EACCES;
-}
-
-static struct sysfs_ops fuse_conn_sysfs_ops = {
-       .show   = &fuse_conn_attr_show,
-       .store  = &fuse_conn_attr_store,
-};
-
-static struct kobj_type ktype_fuse_conn = {
-       .release        = fuse_conn_release,
-       .sysfs_ops      = &fuse_conn_sysfs_ops,
-       .default_attrs  = fuse_conn_attrs,
-};
-
 static decl_subsys(fuse, NULL, NULL);
-static decl_subsys(connections, &ktype_fuse_conn, NULL);
+static decl_subsys(connections, NULL, NULL);
 
 static void fuse_inode_init_once(void *foo, kmem_cache_t *cachep,
                                 unsigned long flags)
@@ -718,6 +648,7 @@ static int __init fuse_init(void)
        printk("fuse init (API version %i.%i)\n",
               FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
 
+       INIT_LIST_HEAD(&fuse_conn_list);
        res = fuse_fs_init();
        if (res)
                goto err;
@@ -730,8 +661,14 @@ static int __init fuse_init(void)
        if (res)
                goto err_dev_cleanup;
 
+       res = fuse_ctl_init();
+       if (res)
+               goto err_sysfs_cleanup;
+
        return 0;
 
+ err_sysfs_cleanup:
+       fuse_sysfs_cleanup();
  err_dev_cleanup:
        fuse_dev_cleanup();
  err_fs_cleanup:
@@ -744,6 +681,7 @@ static void __exit fuse_exit(void)
 {
        printk(KERN_DEBUG "fuse exit\n");
 
+       fuse_ctl_cleanup();
        fuse_sysfs_cleanup();
        fuse_fs_cleanup();
        fuse_dev_cleanup();