ceph: improve fragtree change detection

check if number of splits in i_fragtree is equal to number of splits
in mds reply

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

diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 09713f32ea88e15bdeaafff2d94f483a4d05f505..7ba8e1c2557bbb5e8ca979fcb661cd4ad8d8a685 100644 (file)
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -326,13 +326,15 @@ static int ceph_fill_fragtree(struct inode *inode,
        struct ceph_inode_info *ci = ceph_inode(inode);
        struct ceph_inode_frag *frag, *prev_frag = NULL;
        struct rb_node *rb_node;
-       int i;
-       u32 id, nsplits;
+       unsigned i, split_by, nsplits;
+       u32 id;
        bool update = false;
 
        mutex_lock(&ci->i_fragtree_mutex);
        nsplits = le32_to_cpu(fragtree->nsplits);
-       if (nsplits) {
+       if (nsplits != ci->i_fragtree_nsplits) {
+               update = true;
+       } else if (nsplits) {
                i = prandom_u32() % nsplits;
                id = le32_to_cpu(fragtree->splits[i].frag);
                if (!__ceph_find_frag(ci, id))
@@ -360,6 +362,13 @@ static int ceph_fill_fragtree(struct inode *inode,
        rb_node = rb_first(&ci->i_fragtree);
        for (i = 0; i < nsplits; i++) {
                id = le32_to_cpu(fragtree->splits[i].frag);
+               split_by = le32_to_cpu(fragtree->splits[i].by);
+               if (split_by == 0 || ceph_frag_bits(id) + split_by > 24) {
+                       pr_err("fill_fragtree %llx.%llx invalid split %d/%u, "
+                              "frag %x split by %d\n", ceph_vinop(inode),
+                              i, nsplits, id, split_by);
+                       continue;
+               }
                frag = NULL;
                while (rb_node) {
                        frag = rb_entry(rb_node, struct ceph_inode_frag, node);
@@ -375,6 +384,8 @@ static int ceph_fill_fragtree(struct inode *inode,
                        if (frag->split_by > 0 ||
                            !is_frag_child(frag->frag, prev_frag)) {
                                rb_erase(&frag->node, &ci->i_fragtree);
+                               if (frag->split_by > 0)
+                                       ci->i_fragtree_nsplits--;
                                kfree(frag);
                        }
                        frag = NULL;
@@ -384,7 +395,9 @@ static int ceph_fill_fragtree(struct inode *inode,
                        if (IS_ERR(frag))
                                continue;
                }
-               frag->split_by = le32_to_cpu(fragtree->splits[i].by);
+               if (frag->split_by == 0)
+                       ci->i_fragtree_nsplits++;
+               frag->split_by = split_by;
                dout(" frag %x split by %d\n", frag->frag, frag->split_by);
                prev_frag = frag;
        }
@@ -395,6 +408,8 @@ static int ceph_fill_fragtree(struct inode *inode,
                if (frag->split_by > 0 ||
                    !is_frag_child(frag->frag, prev_frag)) {
                        rb_erase(&frag->node, &ci->i_fragtree);
+                       if (frag->split_by > 0)
+                               ci->i_fragtree_nsplits--;
                        kfree(frag);
                }
        }
@@ -546,6 +561,7 @@ void ceph_destroy_inode(struct inode *inode)
                rb_erase(n, &ci->i_fragtree);
                kfree(frag);
        }
+       ci->i_fragtree_nsplits = 0;
 
        __ceph_destroy_xattrs(ci);
        if (ci->i_xattrs.blob)

diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index c9b671dfff810b8789b56724e2cc9884160acd85..a268f18d21190cee079ca429be23183f1b2cde6b 100644 (file)
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -297,6 +297,7 @@ struct ceph_inode_info {
        u64 i_files, i_subdirs;
 
        struct rb_root i_fragtree;
+       int i_fragtree_nsplits;
        struct mutex i_fragtree_mutex;
 
        struct ceph_inode_xattrs_info i_xattrs;