fuse: extract fuse_fill_super_common()

[sfrench/cifs-2.6.git] / fs / fuse / inode.c

diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 5d455f4d6195ee583e07367ae81516416cc71dee..30d92e633eceade5d688bd345c118be1e2e1a6c1 100644 (file)
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -64,23 +64,6 @@ MODULE_PARM_DESC(max_user_congthresh,
 static struct file_system_type fuseblk_fs_type;
 #endif
 
-struct fuse_fs_context {
-       const char      *subtype;
-       bool            is_bdev;
-       int fd;
-       unsigned rootmode;
-       kuid_t user_id;
-       kgid_t group_id;
-       unsigned fd_present:1;
-       unsigned rootmode_present:1;
-       unsigned user_id_present:1;
-       unsigned group_id_present:1;
-       unsigned default_permissions:1;
-       unsigned allow_other:1;
-       unsigned max_read;
-       unsigned blksize;
-};
-
 struct fuse_forget_link *fuse_alloc_forget(void)
 {
        return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL);
@@ -1100,16 +1083,13 @@ void fuse_dev_free(struct fuse_dev *fud)
 }
 EXPORT_SYMBOL_GPL(fuse_dev_free);
 
-static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc)
+int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx)
 {
-       struct fuse_fs_context *ctx = fsc->fs_private;
        struct fuse_dev *fud;
-       struct fuse_conn *fc;
+       struct fuse_conn *fc = get_fuse_conn_super(sb);
        struct inode *root;
-       struct file *file;
        struct dentry *root_dentry;
        int err;
-       int is_bdev = sb->s_bdev != NULL;
 
        err = -EINVAL;
        if (sb->s_flags & SB_MANDLOCK)
@@ -1117,7 +1097,7 @@ static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc)
 
        sb->s_flags &= ~(SB_NOSEC | SB_I_VERSION);
 
-       if (is_bdev) {
+       if (ctx->is_bdev) {
 #ifdef CONFIG_BLOCK
                err = -EINVAL;
                if (!sb_set_blocksize(sb, ctx->blksize))
@@ -1140,19 +1120,6 @@ static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc)
        if (sb->s_user_ns != &init_user_ns)
                sb->s_iflags |= SB_I_UNTRUSTED_MOUNTER;
 
-       file = fget(ctx->fd);
-       err = -EINVAL;
-       if (!file)
-               goto err;
-
-       /*
-        * Require mount to happen from the same user namespace which
-        * opened /dev/fuse to prevent potential attacks.
-        */
-       if (file->f_op != &fuse_dev_operations ||
-           file->f_cred->user_ns != sb->s_user_ns)
-               goto err_fput;
-
        /*
         * If we are not in the initial user namespace posix
         * acls must be translated.
@@ -1160,17 +1127,9 @@ static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc)
        if (sb->s_user_ns != &init_user_ns)
                sb->s_xattr = fuse_no_acl_xattr_handlers;
 
-       fc = kmalloc(sizeof(*fc), GFP_KERNEL);
-       err = -ENOMEM;
-       if (!fc)
-               goto err_fput;
-
-       fuse_conn_init(fc, sb->s_user_ns);
-       fc->release = fuse_free_conn;
-
        fud = fuse_dev_alloc(fc);
        if (!fud)
-               goto err_put_conn;
+               goto err;
 
        fc->dev = sb->s_dev;
        fc->sb = sb;
@@ -1188,10 +1147,7 @@ static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc)
        fc->user_id = ctx->user_id;
        fc->group_id = ctx->group_id;
        fc->max_read = max_t(unsigned, 4096, ctx->max_read);
-       fc->destroy = is_bdev;
-
-       /* Used by get_root_inode() */
-       sb->s_fs_info = fc;
+       fc->destroy = ctx->is_bdev;
 
        err = -ENOMEM;
        root = fuse_get_root_inode(sb, ctx->rootmode);
@@ -1204,7 +1160,7 @@ static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc)
 
        mutex_lock(&fuse_mutex);
        err = -EINVAL;
-       if (file->private_data)
+       if (*ctx->fudptr)
                goto err_unlock;
 
        err = fuse_ctl_add_conn(fc);
@@ -1213,24 +1169,62 @@ static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc)
 
        list_add_tail(&fc->entry, &fuse_conn_list);
        sb->s_root = root_dentry;
-       file->private_data = fud;
+       *ctx->fudptr = fud;
        mutex_unlock(&fuse_mutex);
+       return 0;
+
+ err_unlock:
+       mutex_unlock(&fuse_mutex);
+       dput(root_dentry);
+ err_dev_free:
+       fuse_dev_free(fud);
+ err:
+       return err;
+}
+EXPORT_SYMBOL_GPL(fuse_fill_super_common);
+
+static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc)
+{
+       struct fuse_fs_context *ctx = fsc->fs_private;
+       struct file *file;
+       int err;
+       struct fuse_conn *fc;
+
+       err = -EINVAL;
+       file = fget(ctx->fd);
+       if (!file)
+               goto err;
+
+       /*
+        * Require mount to happen from the same user namespace which
+        * opened /dev/fuse to prevent potential attacks.
+        */
+       if ((file->f_op != &fuse_dev_operations) ||
+           (file->f_cred->user_ns != sb->s_user_ns))
+               goto err_fput;
+       ctx->fudptr = &file->private_data;
+
+       fc = kmalloc(sizeof(*fc), GFP_KERNEL);
+       err = -ENOMEM;
+       if (!fc)
+               goto err_fput;
+
+       fuse_conn_init(fc, sb->s_user_ns);
+       fc->release = fuse_free_conn;
+       sb->s_fs_info = fc;
+
+       err = fuse_fill_super_common(sb, ctx);
+       if (err)
+               goto err_put_conn;
        /*
         * atomic_dec_and_test() in fput() provides the necessary
         * memory barrier for file->private_data to be visible on all
         * CPUs after this
         */
        fput(file);
-
-       fuse_send_init(fc);
-
+       fuse_send_init(get_fuse_conn_super(sb));
        return 0;
 
- err_unlock:
-       mutex_unlock(&fuse_mutex);
-       dput(root_dentry);
- err_dev_free:
-       fuse_dev_free(fud);
  err_put_conn:
        fuse_conn_put(fc);
        sb->s_fs_info = NULL;