1 files changed, 229 insertions, 39 deletions

diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 04c80cc957a3..c755a0440a66 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -24,6 +24,13 @@ MODULE_LICENSE("GPL");
 
 spinlock_t fuse_lock;
 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);
+};
 
 #define FUSE_SUPER_MAGIC 0x65735546
 
@@ -189,6 +196,11 @@ struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
         return inode;
 }
 
+static void fuse_umount_begin(struct super_block *sb)
+{
+        fuse_abort_conn(get_fuse_conn_super(sb));
+}
+
 static void fuse_put_super(struct super_block *sb)
 {
         struct fuse_conn *fc = get_fuse_conn_super(sb);
@@ -200,14 +212,13 @@ static void fuse_put_super(struct super_block *sb)
 
         spin_lock(&fuse_lock);
         fc->mounted = 0;
-        fc->user_id = 0;
-        fc->group_id = 0;
-        fc->flags = 0;
+        fc->connected = 0;
+        spin_unlock(&fuse_lock);
+        up_write(&fc->sbput_sem);
         /* Flush all readers on this fs */
         wake_up_all(&fc->waitq);
-        up_write(&fc->sbput_sem);
-        fuse_release_conn(fc);
-        spin_unlock(&fuse_lock);
+        kobject_del(&fc->kobj);
+        kobject_put(&fc->kobj);
 }
 
 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
@@ -356,8 +367,10 @@ static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
         return 0;
 }
 
-static void free_conn(struct fuse_conn *fc)
+static void fuse_conn_release(struct kobject *kobj)
 {
+        struct fuse_conn *fc = get_fuse_conn_kobj(kobj);
+
         while (!list_empty(&fc->unused_list)) {
                 struct fuse_req *req;
                 req = list_entry(fc->unused_list.next, struct fuse_req, list);
@@ -367,33 +380,28 @@ static void free_conn(struct fuse_conn *fc)
         kfree(fc);
 }
 
-/* Must be called with the fuse lock held */
-void fuse_release_conn(struct fuse_conn *fc)
-{
-        fc->count--;
-        if (!fc->count)
-                free_conn(fc);
-}
-
 static struct fuse_conn *new_conn(void)
 {
         struct fuse_conn *fc;
 
-        fc = kmalloc(sizeof(*fc), GFP_KERNEL);
-        if (fc != NULL) {
+        fc = kzalloc(sizeof(*fc), GFP_KERNEL);
+        if (fc) {
                 int i;
-                memset(fc, 0, sizeof(*fc));
                 init_waitqueue_head(&fc->waitq);
                 INIT_LIST_HEAD(&fc->pending);
                 INIT_LIST_HEAD(&fc->processing);
+                INIT_LIST_HEAD(&fc->io);
                 INIT_LIST_HEAD(&fc->unused_list);
                 INIT_LIST_HEAD(&fc->background);
-                sema_init(&fc->outstanding_sem, 0);
+                sema_init(&fc->outstanding_sem, 1); /* One for INIT */
                 init_rwsem(&fc->sbput_sem);
+                kobj_set_kset_s(fc, connections_subsys);
+                kobject_init(&fc->kobj);
+                atomic_set(&fc->num_waiting, 0);
                 for (i = 0; i < FUSE_MAX_OUTSTANDING; i++) {
                         struct fuse_req *req = fuse_request_alloc();
                         if (!req) {
-                                free_conn(fc);
+                                kobject_put(&fc->kobj);
                                 return NULL;
                         }
                         list_add(&req->list, &fc->unused_list);
@@ -408,25 +416,32 @@ static struct fuse_conn *new_conn(void)
 static struct fuse_conn *get_conn(struct file *file, struct super_block *sb)
 {
         struct fuse_conn *fc;
+        int err;
 
+        err = -EINVAL;
         if (file->f_op != &fuse_dev_operations)
-                return ERR_PTR(-EINVAL);
+                goto out_err;
+
+        err = -ENOMEM;
         fc = new_conn();
-        if (fc == NULL)
-                return ERR_PTR(-ENOMEM);
+        if (!fc)
+                goto out_err;
+
         spin_lock(&fuse_lock);
-        if (file->private_data) {
-                free_conn(fc);
-                fc = ERR_PTR(-EINVAL);
-        } else {
-                file->private_data = fc;
-                *get_fuse_conn_super_p(sb) = fc;
-                fc->mounted = 1;
-                fc->connected = 1;
-                fc->count = 2;
-        }
+        err = -EINVAL;
+        if (file->private_data)
+                goto out_unlock;
+
+        kobject_get(&fc->kobj);
+        file->private_data = fc;
         spin_unlock(&fuse_lock);
         return fc;
+
+ out_unlock:
+        spin_unlock(&fuse_lock);
+        kobject_put(&fc->kobj);
+ out_err:
+        return ERR_PTR(err);
 }
 
 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
@@ -445,16 +460,74 @@ static struct super_operations fuse_super_operations = {
         .read_inode     = fuse_read_inode,
         .clear_inode    = fuse_clear_inode,
         .put_super      = fuse_put_super,
+        .umount_begin   = fuse_umount_begin,
         .statfs         = fuse_statfs,
         .show_options   = fuse_show_options,
 };
 
+static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
+{
+        int i;
+        struct fuse_init_out *arg = &req->misc.init_out;
+
+        if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
+                fc->conn_error = 1;
+        else {
+                fc->minor = arg->minor;
+                fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
+        }
+
+        /* After INIT reply is received other requests can go
+           out.  So do (FUSE_MAX_OUTSTANDING - 1) number of
+           up()s on outstanding_sem.  The last up() is done in
+           fuse_putback_request() */
+        for (i = 1; i < FUSE_MAX_OUTSTANDING; i++)
+                up(&fc->outstanding_sem);
+
+        fuse_put_request(fc, req);
+}
+
+static void fuse_send_init(struct fuse_conn *fc)
+{
+        /* This is called from fuse_read_super() so there's guaranteed
+           to be exactly one request available */
+        struct fuse_req *req = fuse_get_request(fc);
+        struct fuse_init_in *arg = &req->misc.init_in;
+
+        arg->major = FUSE_KERNEL_VERSION;
+        arg->minor = FUSE_KERNEL_MINOR_VERSION;
+        req->in.h.opcode = FUSE_INIT;
+        req->in.numargs = 1;
+        req->in.args[0].size = sizeof(*arg);
+        req->in.args[0].value = arg;
+        req->out.numargs = 1;
+        /* Variable length arguement used for backward compatibility
+           with interface version < 7.5.  Rest of init_out is zeroed
+           by do_get_request(), so a short reply is not a problem */
+        req->out.argvar = 1;
+        req->out.args[0].size = sizeof(struct fuse_init_out);
+        req->out.args[0].value = &req->misc.init_out;
+        req->end = process_init_reply;
+        request_send_background(fc, req);
+}
+
+static unsigned long long conn_id(void)
+{
+        static unsigned long long ctr = 1;
+        unsigned long long val;
+        spin_lock(&fuse_lock);
+        val = ctr++;
+        spin_unlock(&fuse_lock);
+        return val;
+}
+
 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 {
         struct fuse_conn *fc;
         struct inode *root;
         struct fuse_mount_data d;
         struct file *file;
+        struct dentry *root_dentry;
         int err;
 
         if (!parse_fuse_opt((char *) data, &d))
@@ -482,23 +555,42 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
         if (fc->max_read / PAGE_CACHE_SIZE < fc->bdi.ra_pages)
                 fc->bdi.ra_pages = fc->max_read / PAGE_CACHE_SIZE;
 
+        /* Used by get_root_inode() */
+        sb->s_fs_info = fc;
+
         err = -ENOMEM;
         root = get_root_inode(sb, d.rootmode);
-        if (root == NULL)
+        if (!root)
                 goto err;
 
-        sb->s_root = d_alloc_root(root);
-        if (!sb->s_root) {
+        root_dentry = d_alloc_root(root);
+        if (!root_dentry) {
                 iput(root);
                 goto err;
         }
+
+        err = kobject_set_name(&fc->kobj, "%llu", conn_id());
+        if (err)
+                goto err_put_root;
+
+        err = kobject_add(&fc->kobj);
+        if (err)
+                goto err_put_root;
+
+        sb->s_root = root_dentry;
+        spin_lock(&fuse_lock);
+        fc->mounted = 1;
+        fc->connected = 1;
+        spin_unlock(&fuse_lock);
+
         fuse_send_init(fc);
+
         return 0;
 
+ err_put_root:
+        dput(root_dentry);
  err:
-        spin_lock(&fuse_lock);
-        fuse_release_conn(fc);
-        spin_unlock(&fuse_lock);
+        kobject_put(&fc->kobj);
         return err;
 }
 
@@ -516,6 +608,69 @@ 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 void fuse_inode_init_once(void *foo, kmem_cache_t *cachep,
                                  unsigned long flags)
 {
@@ -553,6 +708,34 @@ static void fuse_fs_cleanup(void)
         kmem_cache_destroy(fuse_inode_cachep);
 }
 
+static int fuse_sysfs_init(void)
+{
+        int err;
+
+        kset_set_kset_s(&fuse_subsys, fs_subsys);
+        err = subsystem_register(&fuse_subsys);
+        if (err)
+                goto out_err;
+
+        kset_set_kset_s(&connections_subsys, fuse_subsys);
+        err = subsystem_register(&connections_subsys);
+        if (err)
+                goto out_fuse_unregister;
+
+        return 0;
+
+ out_fuse_unregister:
+        subsystem_unregister(&fuse_subsys);
+ out_err:
+        return err;
+}
+
+static void fuse_sysfs_cleanup(void)
+{
+        subsystem_unregister(&connections_subsys);
+        subsystem_unregister(&fuse_subsys);
+}
+
 static int __init fuse_init(void)
 {
         int res;
@@ -569,8 +752,14 @@ static int __init fuse_init(void)
         if (res)
                 goto err_fs_cleanup;
 
+        res = fuse_sysfs_init();
+        if (res)
+                goto err_dev_cleanup;
+
         return 0;
 
+ err_dev_cleanup:
+        fuse_dev_cleanup();
  err_fs_cleanup:
         fuse_fs_cleanup();
  err:
@@ -581,6 +770,7 @@ static void __exit fuse_exit(void)
 {
         printk(KERN_DEBUG "fuse exit\n");
 
+        fuse_sysfs_cleanup();
         fuse_fs_cleanup();
         fuse_dev_cleanup();
 }