1 files changed, 23 insertions, 24 deletions

diff --git a/fs/nilfs2/cpfile.c b/fs/nilfs2/cpfile.c
index cadd36b14d07..7d49813f66d6 100644
--- a/fs/nilfs2/cpfile.c
+++ b/fs/nilfs2/cpfile.c
@@ -295,10 +295,6 @@ int nilfs_cpfile_delete_checkpoints(struct inode *cpfile,
                 return -EINVAL;
         }
 
-        /* cannot delete the latest checkpoint */
-        if (start == nilfs_mdt_cno(cpfile) - 1)
-                return -EPERM;
-
         down_write(&NILFS_MDT(cpfile)->mi_sem);
 
         ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
@@ -384,9 +380,10 @@ static void nilfs_cpfile_checkpoint_to_cpinfo(struct inode *cpfile,
 }
 
 static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 *cnop,
-                                          struct nilfs_cpinfo *ci, size_t nci)
+                                          void *buf, unsigned cisz, size_t nci)
 {
         struct nilfs_checkpoint *cp;
+        struct nilfs_cpinfo *ci = buf;
         struct buffer_head *bh;
         size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size;
         __u64 cur_cno = nilfs_mdt_cno(cpfile), cno = *cnop;
@@ -410,17 +407,22 @@ static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 *cnop,
                 kaddr = kmap_atomic(bh->b_page, KM_USER0);
                 cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
                 for (i = 0; i < ncps && n < nci; i++, cp = (void *)cp + cpsz) {
-                        if (!nilfs_checkpoint_invalid(cp))
-                                nilfs_cpfile_checkpoint_to_cpinfo(
-                                        cpfile, cp, &ci[n++]);
+                        if (!nilfs_checkpoint_invalid(cp)) {
+                                nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp,
+                                                                  ci);
+                                ci = (void *)ci + cisz;
+                                n++;
+                        }
                 }
                 kunmap_atomic(kaddr, KM_USER0);
                 brelse(bh);
         }
 
         ret = n;
-        if (n > 0)
-                *cnop = ci[n - 1].ci_cno + 1;
+        if (n > 0) {
+                ci = (void *)ci - cisz;
+                *cnop = ci->ci_cno + 1;
+        }
 
  out:
         up_read(&NILFS_MDT(cpfile)->mi_sem);
@@ -428,11 +430,12 @@ static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 *cnop,
 }
 
 static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop,
-                                          struct nilfs_cpinfo *ci, size_t nci)
+                                          void *buf, unsigned cisz, size_t nci)
 {
         struct buffer_head *bh;
         struct nilfs_cpfile_header *header;
         struct nilfs_checkpoint *cp;
+        struct nilfs_cpinfo *ci = buf;
         __u64 curr = *cnop, next;
         unsigned long curr_blkoff, next_blkoff;
         void *kaddr;
@@ -472,7 +475,9 @@ static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop,
                 if (unlikely(nilfs_checkpoint_invalid(cp) ||
                              !nilfs_checkpoint_snapshot(cp)))
                         break;
-                nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, &ci[n++]);
+                nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, ci);
+                ci = (void *)ci + cisz;
+                n++;
                 next = le64_to_cpu(cp->cp_snapshot_list.ssl_next);
                 if (next == 0)
                         break; /* reach end of the snapshot list */
@@ -511,13 +516,13 @@ static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop,
  */
 
 ssize_t nilfs_cpfile_get_cpinfo(struct inode *cpfile, __u64 *cnop, int mode,
-                                struct nilfs_cpinfo *ci, size_t nci)
+                                void *buf, unsigned cisz, size_t nci)
 {
         switch (mode) {
         case NILFS_CHECKPOINT:
-                return nilfs_cpfile_do_get_cpinfo(cpfile, cnop, ci, nci);
+                return nilfs_cpfile_do_get_cpinfo(cpfile, cnop, buf, cisz, nci);
         case NILFS_SNAPSHOT:
-                return nilfs_cpfile_do_get_ssinfo(cpfile, cnop, ci, nci);
+                return nilfs_cpfile_do_get_ssinfo(cpfile, cnop, buf, cisz, nci);
         default:
                 return -EINVAL;
         }
@@ -533,20 +538,14 @@ int nilfs_cpfile_delete_checkpoint(struct inode *cpfile, __u64 cno)
         struct nilfs_cpinfo ci;
         __u64 tcno = cno;
         ssize_t nci;
-        int ret;
 
-        nci = nilfs_cpfile_do_get_cpinfo(cpfile, &tcno, &ci, 1);
+        nci = nilfs_cpfile_do_get_cpinfo(cpfile, &tcno, &ci, sizeof(ci), 1);
         if (nci < 0)
                 return nci;
         else if (nci == 0 || ci.ci_cno != cno)
                 return -ENOENT;
-
-        /* cannot delete the latest checkpoint nor snapshots */
-        ret = nilfs_cpinfo_snapshot(&ci);
-        if (ret < 0)
-                return ret;
-        else if (ret > 0 || cno == nilfs_mdt_cno(cpfile) - 1)
-                return -EPERM;
+        else if (nilfs_cpinfo_snapshot(&ci))
+                return -EBUSY;
 
         return nilfs_cpfile_delete_checkpoints(cpfile, cno, cno + 1);
 }