The CephFS kernel client doesn't enforce quotas that are set in a directory that isn't visible in the mount point. For example, given the path '/dir1/dir2', if quotas are set in 'dir1' and the mount is done in with
mount -t ceph <server>:<port>:/dir1/ /mnt then the client can't access the 'dir1' inode from the quota realm dir2 belongs to. This patch fixes this by simply doing an MDS LOOKUPINO Op and grabbing a reference to it (so that it doesn't disappear again). This also requires an extra field in ceph_snap_realm so that we know we have to release that reference when destroying the realm. Links: https://tracker.ceph.com/issues/3848 Reported-by: Hendrik Peyerl <[email protected]> Signed-off-by: Luis Henriques <[email protected]> --- fs/ceph/caps.c | 2 +- fs/ceph/quota.c | 30 +++++++++++++++++++++++++++--- fs/ceph/snap.c | 3 +++ fs/ceph/super.h | 2 ++ 4 files changed, 33 insertions(+), 4 deletions(-) diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index bba28a5034ba..e79994ff53d6 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -1035,7 +1035,7 @@ static void drop_inode_snap_realm(struct ceph_inode_info *ci) list_del_init(&ci->i_snap_realm_item); ci->i_snap_realm_counter++; ci->i_snap_realm = NULL; - if (realm->ino == ci->i_vino.ino) + if ((realm->ino == ci->i_vino.ino) && !realm->own_inode) realm->inode = NULL; spin_unlock(&realm->inodes_with_caps_lock); ceph_put_snap_realm(ceph_sb_to_client(ci->vfs_inode.i_sb)->mdsc, diff --git a/fs/ceph/quota.c b/fs/ceph/quota.c index 9455d3aef0c3..f6b972d222e4 100644 --- a/fs/ceph/quota.c +++ b/fs/ceph/quota.c @@ -22,7 +22,16 @@ void ceph_adjust_quota_realms_count(struct inode *inode, bool inc) static inline bool ceph_has_realms_with_quotas(struct inode *inode) { struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc; - return atomic64_read(&mdsc->quotarealms_count) > 0; + struct super_block *sb = mdsc->fsc->sb; + + if (atomic64_read(&mdsc->quotarealms_count) > 0) + return true; + /* if root is the real CephFS root, we don't have quota realms */ + if (sb->s_root->d_inode && + (sb->s_root->d_inode->i_ino == CEPH_INO_ROOT)) + return false; + /* otherwise, we can't know for sure */ + return true; } void ceph_handle_quota(struct ceph_mds_client *mdsc, @@ -166,6 +175,7 @@ static bool check_quota_exceeded(struct inode *inode, enum quota_check_op op, return false; down_read(&mdsc->snap_rwsem); +restart: realm = ceph_inode(inode)->i_snap_realm; if (realm) ceph_get_snap_realm(mdsc, realm); @@ -176,8 +186,22 @@ static bool check_quota_exceeded(struct inode *inode, enum quota_check_op op, spin_lock(&realm->inodes_with_caps_lock); in = realm->inode ? igrab(realm->inode) : NULL; spin_unlock(&realm->inodes_with_caps_lock); - if (!in) - break; + if (!in) { + up_read(&mdsc->snap_rwsem); + in = ceph_lookup_inode(inode->i_sb, realm->ino); + down_read(&mdsc->snap_rwsem); + if (IS_ERR(in)) { + pr_warn("Can't lookup inode %llx (err: %ld)\n", + realm->ino, PTR_ERR(in)); + break; + } + spin_lock(&realm->inodes_with_caps_lock); + realm->inode = in; + realm->own_inode = true; + spin_unlock(&realm->inodes_with_caps_lock); + ceph_put_snap_realm(mdsc, realm); + goto restart; + } ci = ceph_inode(in); spin_lock(&ci->i_ceph_lock); diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c index f74193da0e09..c84ed8e8526a 100644 --- a/fs/ceph/snap.c +++ b/fs/ceph/snap.c @@ -117,6 +117,7 @@ static struct ceph_snap_realm *ceph_create_snap_realm( atomic_set(&realm->nref, 1); /* for caller */ realm->ino = ino; + realm->own_inode = false; INIT_LIST_HEAD(&realm->children); INIT_LIST_HEAD(&realm->child_item); INIT_LIST_HEAD(&realm->empty_item); @@ -184,6 +185,8 @@ static void __destroy_snap_realm(struct ceph_mds_client *mdsc, kfree(realm->prior_parent_snaps); kfree(realm->snaps); ceph_put_snap_context(realm->cached_context); + if (realm->own_inode && realm->inode) + iput(realm->inode); kfree(realm); } diff --git a/fs/ceph/super.h b/fs/ceph/super.h index ce51e98b08ec..3f0d74d2150f 100644 --- a/fs/ceph/super.h +++ b/fs/ceph/super.h @@ -764,6 +764,8 @@ struct ceph_snap_realm { atomic_t nref; struct rb_node node; + bool own_inode; /* true if we hold a ref to the inode */ + u64 created, seq; u64 parent_ino; u64 parent_since; /* snapid when our current parent became so */
