fuse: separate out fuse_conn_init() from new_conn()

Separate out fuse_conn_init() from new_conn() and while at it
initialize fuse_conn->entry during conn initialization.

This will be used by CUSE.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

2 files changed, 67 insertions, 57 deletions

diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index c08e7e890923..eb488d48b833 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -650,6 +650,11 @@ void fuse_invalidate_entry_cache(struct dentry *entry);
 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
 
 /**
+ * Initialize fuse_conn
+ */
+int fuse_conn_init(struct fuse_conn *fc, struct super_block *sb);
+
+/**
  * Release reference to fuse_conn
  */
 void fuse_conn_put(struct fuse_conn *fc);
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index ee91639c6d35..6c9fa03aa367 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -462,70 +462,69 @@ static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
         return 0;
 }
 
-static struct fuse_conn *new_conn(struct super_block *sb)
+int fuse_conn_init(struct fuse_conn *fc, struct super_block *sb)
 {
-        struct fuse_conn *fc;
         int err;
 
-        fc = kzalloc(sizeof(*fc), GFP_KERNEL);
-        if (fc) {
-                spin_lock_init(&fc->lock);
-                mutex_init(&fc->inst_mutex);
-                atomic_set(&fc->count, 1);
-                init_waitqueue_head(&fc->waitq);
-                init_waitqueue_head(&fc->blocked_waitq);
-                init_waitqueue_head(&fc->reserved_req_waitq);
-                INIT_LIST_HEAD(&fc->pending);
-                INIT_LIST_HEAD(&fc->processing);
-                INIT_LIST_HEAD(&fc->io);
-                INIT_LIST_HEAD(&fc->interrupts);
-                INIT_LIST_HEAD(&fc->bg_queue);
-                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;
-                /* fuse does it's own writeback accounting */
-                fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB;
-                fc->khctr = 0;
-                fc->polled_files = RB_ROOT;
-                fc->dev = sb->s_dev;
-                err = bdi_init(&fc->bdi);
-                if (err)
-                        goto error_kfree;
-                if (sb->s_bdev) {
-                        err = bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
-                                           MAJOR(fc->dev), MINOR(fc->dev));
-                } else {
-                        err = bdi_register_dev(&fc->bdi, fc->dev);
-                }
-                if (err)
-                        goto error_bdi_destroy;
-                /*
-                 * For a single fuse filesystem use max 1% of dirty +
-                 * writeback threshold.
-                 *
-                 * This gives about 1M of write buffer for memory maps on a
-                 * machine with 1G and 10% dirty_ratio, which should be more
-                 * than enough.
-                 *
-                 * Privileged users can raise it by writing to
-                 *
-                 *    /sys/class/bdi/<bdi>/max_ratio
-                 */
-                bdi_set_max_ratio(&fc->bdi, 1);
-                fc->reqctr = 0;
-                fc->blocked = 1;
-                fc->attr_version = 1;
-                get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
+        memset(fc, 0, sizeof(*fc));
+        spin_lock_init(&fc->lock);
+        mutex_init(&fc->inst_mutex);
+        atomic_set(&fc->count, 1);
+        init_waitqueue_head(&fc->waitq);
+        init_waitqueue_head(&fc->blocked_waitq);
+        init_waitqueue_head(&fc->reserved_req_waitq);
+        INIT_LIST_HEAD(&fc->pending);
+        INIT_LIST_HEAD(&fc->processing);
+        INIT_LIST_HEAD(&fc->io);
+        INIT_LIST_HEAD(&fc->interrupts);
+        INIT_LIST_HEAD(&fc->bg_queue);
+        INIT_LIST_HEAD(&fc->entry);
+        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;
+        /* fuse does it's own writeback accounting */
+        fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB;
+        fc->khctr = 0;
+        fc->polled_files = RB_ROOT;
+        fc->dev = sb->s_dev;
+        err = bdi_init(&fc->bdi);
+        if (err)
+                goto error_mutex_destroy;
+        if (sb->s_bdev) {
+                err = bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
+                                   MAJOR(fc->dev), MINOR(fc->dev));
+        } else {
+                err = bdi_register_dev(&fc->bdi, fc->dev);
         }
-        return fc;
+        if (err)
+                goto error_bdi_destroy;
+        /*
+         * For a single fuse filesystem use max 1% of dirty +
+         * writeback threshold.
+         *
+         * This gives about 1M of write buffer for memory maps on a
+         * machine with 1G and 10% dirty_ratio, which should be more
+         * than enough.
+         *
+         * Privileged users can raise it by writing to
+         *
+         *    /sys/class/bdi/<bdi>/max_ratio
+         */
+        bdi_set_max_ratio(&fc->bdi, 1);
+        fc->reqctr = 0;
+        fc->blocked = 1;
+        fc->attr_version = 1;
+        get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
+
+        return 0;
 
-error_bdi_destroy:
+ error_bdi_destroy:
         bdi_destroy(&fc->bdi);
-error_kfree:
+ error_mutex_destroy:
         mutex_destroy(&fc->inst_mutex);
-        kfree(fc);
-        return NULL;
+        return err;
 }
+EXPORT_SYMBOL_GPL(fuse_conn_init);
 
 void fuse_conn_put(struct fuse_conn *fc)
 {
@@ -828,10 +827,16 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
         if (file->f_op != &fuse_dev_operations)
                 return -EINVAL;
 
-        fc = new_conn(sb);
+        fc = kmalloc(sizeof(*fc), GFP_KERNEL);
         if (!fc)
                 return -ENOMEM;
 
+        err = fuse_conn_init(fc, sb);
+        if (err) {
+                kfree(fc);
+                return err;
+        }
+
         fc->flags = d.flags;
         fc->user_id = d.user_id;
         fc->group_id = d.group_id;