ceph: must hold snap_rwsem when filling inode for async create

...and add a lockdep assertion for it to ceph_fill_inode().

Cc: stable@vger.kernel.org # v5.7+
Fixes: 9a8d03ca2e2c3 ("ceph: attempt to do async create when possible")
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 77fc037..4dc9688 100644 (file)
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -578,6 +578,7 @@ static int ceph_finish_async_create(struct inode *dir, struct dentry *dentry,
        struct ceph_inode_info *ci = ceph_inode(dir);
        struct inode *inode;
        struct timespec64 now;
+       struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
        struct ceph_vino vino = { .ino = req->r_deleg_ino,
                                  .snap = CEPH_NOSNAP };
 
@@ -615,8 +616,10 @@ static int ceph_finish_async_create(struct inode *dir, struct dentry *dentry,
 
        ceph_file_layout_to_legacy(lo, &in.layout);
 
+       down_read(&mdsc->snap_rwsem);
        ret = ceph_fill_inode(inode, NULL, &iinfo, NULL, req->r_session,
                              req->r_fmode, NULL);
+       up_read(&mdsc->snap_rwsem);
        if (ret) {
                dout("%s failed to fill inode: %d\n", __func__, ret);
                ceph_dir_clear_complete(dir);

diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index e1c63ad..df0c8a7 100644 (file)
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -777,6 +777,8 @@ int ceph_fill_inode(struct inode *inode, struct page *locked_page,
        umode_t mode = le32_to_cpu(info->mode);
        dev_t rdev = le32_to_cpu(info->rdev);
 
+       lockdep_assert_held(&mdsc->snap_rwsem);
+
        dout("%s %p ino %llx.%llx v %llu had %llu\n", __func__,
             inode, ceph_vinop(inode), le64_to_cpu(info->version),
             ci->i_version);