ceph: check OSD caps before read/write

Signed-off-by: Yan, Zheng <zyan@redhat.com>

1 files changed, 203 insertions, 0 deletions

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index feeaf3b65fa0..b96027727248 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -1598,3 +1598,206 @@ int ceph_mmap(struct file *file, struct vm_area_struct *vma)
 	vma->vm_ops = &ceph_vmops;
 	return 0;
 }
+
+enum {
+	POOL_READ	= 1,
+	POOL_WRITE	= 2,
+};
+
+static int __ceph_pool_perm_get(struct ceph_inode_info *ci, u32 pool)
+{
+	struct ceph_fs_client *fsc = ceph_inode_to_client(&ci->vfs_inode);
+	struct ceph_mds_client *mdsc = fsc->mdsc;
+	struct ceph_osd_request *rd_req = NULL, *wr_req = NULL;
+	struct rb_node **p, *parent;
+	struct ceph_pool_perm *perm;
+	struct page **pages;
+	int err = 0, err2 = 0, have = 0;
+
+	down_read(&mdsc->pool_perm_rwsem);
+	p = &mdsc->pool_perm_tree.rb_node;
+	while (*p) {
+		perm = rb_entry(*p, struct ceph_pool_perm, node);
+		if (pool < perm->pool)
+			p = &(*p)->rb_left;
+		else if (pool > perm->pool)
+			p = &(*p)->rb_right;
+		else {
+			have = perm->perm;
+			break;
+		}
+	}
+	up_read(&mdsc->pool_perm_rwsem);
+	if (*p)
+		goto out;
+
+	dout("__ceph_pool_perm_get pool %u no perm cached\n", pool);
+
+	down_write(&mdsc->pool_perm_rwsem);
+	parent = NULL;
+	while (*p) {
+		parent = *p;
+		perm = rb_entry(parent, struct ceph_pool_perm, node);
+		if (pool < perm->pool)
+			p = &(*p)->rb_left;
+		else if (pool > perm->pool)
+			p = &(*p)->rb_right;
+		else {
+			have = perm->perm;
+			break;
+		}
+	}
+	if (*p) {
+		up_write(&mdsc->pool_perm_rwsem);
+		goto out;
+	}
+
+	rd_req = ceph_osdc_alloc_request(&fsc->client->osdc,
+					 ci->i_snap_realm->cached_context,
+					 1, false, GFP_NOFS);
+	if (!rd_req) {
+		err = -ENOMEM;
+		goto out_unlock;
+	}
+
+	rd_req->r_flags = CEPH_OSD_FLAG_READ;
+	osd_req_op_init(rd_req, 0, CEPH_OSD_OP_STAT, 0);
+	rd_req->r_base_oloc.pool = pool;
+	snprintf(rd_req->r_base_oid.name, sizeof(rd_req->r_base_oid.name),
+		 "%llx.00000000", ci->i_vino.ino);
+	rd_req->r_base_oid.name_len = strlen(rd_req->r_base_oid.name);
+
+	wr_req = ceph_osdc_alloc_request(&fsc->client->osdc,
+					 ci->i_snap_realm->cached_context,
+					 1, false, GFP_NOFS);
+	if (!wr_req) {
+		err = -ENOMEM;
+		goto out_unlock;
+	}
+
+	wr_req->r_flags = CEPH_OSD_FLAG_WRITE |
+			  CEPH_OSD_FLAG_ACK | CEPH_OSD_FLAG_ONDISK;
+	osd_req_op_init(wr_req, 0, CEPH_OSD_OP_CREATE, CEPH_OSD_OP_FLAG_EXCL);
+	wr_req->r_base_oloc.pool = pool;
+	wr_req->r_base_oid = rd_req->r_base_oid;
+
+	/* one page should be large enough for STAT data */
+	pages = ceph_alloc_page_vector(1, GFP_KERNEL);
+	if (IS_ERR(pages)) {
+		err = PTR_ERR(pages);
+		goto out_unlock;
+	}
+
+	osd_req_op_raw_data_in_pages(rd_req, 0, pages, PAGE_SIZE,
+				     0, false, true);
+	ceph_osdc_build_request(rd_req, 0, NULL, CEPH_NOSNAP,
+				&ci->vfs_inode.i_mtime);
+	err = ceph_osdc_start_request(&fsc->client->osdc, rd_req, false);
+
+	ceph_osdc_build_request(wr_req, 0, NULL, CEPH_NOSNAP,
+				&ci->vfs_inode.i_mtime);
+	err2 = ceph_osdc_start_request(&fsc->client->osdc, wr_req, false);
+
+	if (!err)
+		err = ceph_osdc_wait_request(&fsc->client->osdc, rd_req);
+	if (!err2)
+		err2 = ceph_osdc_wait_request(&fsc->client->osdc, wr_req);
+
+	if (err >= 0 || err == -ENOENT)
+		have |= POOL_READ;
+	else if (err != -EPERM)
+		goto out_unlock;
+
+	if (err2 == 0 || err2 == -EEXIST)
+		have |= POOL_WRITE;
+	else if (err2 != -EPERM) {
+		err = err2;
+		goto out_unlock;
+	}
+
+	perm = kmalloc(sizeof(*perm), GFP_NOFS);
+	if (!perm) {
+		err = -ENOMEM;
+		goto out_unlock;
+	}
+
+	perm->pool = pool;
+	perm->perm = have;
+	rb_link_node(&perm->node, parent, p);
+	rb_insert_color(&perm->node, &mdsc->pool_perm_tree);
+	err = 0;
+out_unlock:
+	up_write(&mdsc->pool_perm_rwsem);
+
+	if (rd_req)
+		ceph_osdc_put_request(rd_req);
+	if (wr_req)
+		ceph_osdc_put_request(wr_req);
+out:
+	if (!err)
+		err = have;
+	dout("__ceph_pool_perm_get pool %u result = %d\n", pool, err);
+	return err;
+}
+
+int ceph_pool_perm_check(struct ceph_inode_info *ci, int need)
+{
+	u32 pool;
+	int ret, flags;
+
+	if (ceph_test_mount_opt(ceph_inode_to_client(&ci->vfs_inode),
+				NOPOOLPERM))
+		return 0;
+
+	spin_lock(&ci->i_ceph_lock);
+	flags = ci->i_ceph_flags;
+	pool = ceph_file_layout_pg_pool(ci->i_layout);
+	spin_unlock(&ci->i_ceph_lock);
+check:
+	if (flags & CEPH_I_POOL_PERM) {
+		if ((need & CEPH_CAP_FILE_RD) && !(flags & CEPH_I_POOL_RD)) {
+			dout("ceph_pool_perm_check pool %u no read perm\n",
+			     pool);
+			return -EPERM;
+		}
+		if ((need & CEPH_CAP_FILE_WR) && !(flags & CEPH_I_POOL_WR)) {
+			dout("ceph_pool_perm_check pool %u no write perm\n",
+			     pool);
+			return -EPERM;
+		}
+		return 0;
+	}
+
+	ret = __ceph_pool_perm_get(ci, pool);
+	if (ret < 0)
+		return ret;
+
+	flags = CEPH_I_POOL_PERM;
+	if (ret & POOL_READ)
+		flags |= CEPH_I_POOL_RD;
+	if (ret & POOL_WRITE)
+		flags |= CEPH_I_POOL_WR;
+
+	spin_lock(&ci->i_ceph_lock);
+	if (pool == ceph_file_layout_pg_pool(ci->i_layout)) {
+		ci->i_ceph_flags = flags;
+        } else {
+		pool = ceph_file_layout_pg_pool(ci->i_layout);
+		flags = ci->i_ceph_flags;
+	}
+	spin_unlock(&ci->i_ceph_lock);
+	goto check;
+}
+
+void ceph_pool_perm_destroy(struct ceph_mds_client *mdsc)
+{
+	struct ceph_pool_perm *perm;
+	struct rb_node *n;
+
+	while (!RB_EMPTY_ROOT(&mdsc->pool_perm_tree)) {
+		n = rb_first(&mdsc->pool_perm_tree);
+		perm = rb_entry(n, struct ceph_pool_perm, node);
+		rb_erase(n, &mdsc->pool_perm_tree);
+		kfree(perm);
+	}
+}