Re: [PATCH 3/3] ceph: must hold snap_rwsem when filling inode for async create

On Thu, Jun 3, 2021 at 6:52 PM Jeff Layton jlayton@kernel.org wrote:

...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

---

fs/ceph/file.c | 3 +++ fs/ceph/inode.c | 2 ++ 2 files changed, 5 insertions(+)

diff --git a/fs/ceph/file.c b/fs/ceph/file.c index a01ad342a91d..d3874c2df4b1 100644 --- 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 e1c63adb196d..df0c8a724609 100644 --- 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);
  

-- 2.31.1

Reviewed-by: Ilya Dryomov idryomov@gmail.com

Thanks,

Ilya