1 files changed, 18 insertions, 12 deletions

diff --git a/fs/nilfs2/cpfile.c b/fs/nilfs2/cpfile.c
index a4c9550fd774..50dff147744f 100644
--- a/fs/nilfs2/cpfile.c
+++ b/fs/nilfs2/cpfile.c
@@ -431,7 +431,7 @@ static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop,
         __u64 curr = *cnop, next;
         unsigned long curr_blkoff, next_blkoff;
         void *kaddr;
-        int n, ret;
+        int n = 0, ret;
 
         down_read(&NILFS_MDT(cpfile)->mi_sem);
 
@@ -455,27 +455,33 @@ static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop,
 
         curr_blkoff = nilfs_cpfile_get_blkoff(cpfile, curr);
         ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr, 0, &bh);
-        if (ret < 0)
+        if (unlikely(ret < 0)) {
+                if (ret == -ENOENT)
+                        ret = 0; /* No snapshots (started from a hole block) */
                 goto out;
+        }
         kaddr = kmap_atomic(bh->b_page, KM_USER0);
-        for (n = 0; n < nci; n++) {
-                cp = nilfs_cpfile_block_get_checkpoint(
-                        cpfile, curr, bh, kaddr);
-                nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, &ci[n]);
-                next = le64_to_cpu(cp->cp_snapshot_list.ssl_next);
-                if (next == 0) {
-                        curr = ~(__u64)0; /* Terminator */
-                        n++;
+        while (n < nci) {
+                cp = nilfs_cpfile_block_get_checkpoint(cpfile, curr, bh, kaddr);
+                curr = ~(__u64)0; /* Terminator */
+                if (unlikely(nilfs_checkpoint_invalid(cp) ||
+                             !nilfs_checkpoint_snapshot(cp)))
                         break;
-                }
+                nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, &ci[n++]);
+                next = le64_to_cpu(cp->cp_snapshot_list.ssl_next);
+                if (next == 0)
+                        break; /* reach end of the snapshot list */
+
                 next_blkoff = nilfs_cpfile_get_blkoff(cpfile, next);
                 if (curr_blkoff != next_blkoff) {
                         kunmap_atomic(kaddr, KM_USER0);
                         brelse(bh);
                         ret = nilfs_cpfile_get_checkpoint_block(cpfile, next,
                                                                 0, &bh);
-                        if (ret < 0)
+                        if (unlikely(ret < 0)) {
+                                WARN_ON(ret == -ENOENT);
                                 goto out;
+                        }
                         kaddr = kmap_atomic(bh->b_page, KM_USER0);
                 }
                 curr = next;