nilfs2: replace BUG_ON and BUG calls triggerable from ioctl

Pekka Enberg advised me:
> It would be nice if BUG(), BUG_ON(), and panic() calls would be
> converted to proper error handling using WARN_ON() calls. The BUG()
> call in nilfs_cpfile_delete_checkpoints(), for example, looks to be
> triggerable from user-space via the ioctl() system call.

This will follow the comment and keep them to a minimum.

Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 7 deletions

diff --git a/fs/nilfs2/dat.c b/fs/nilfs2/dat.c
index 9360920f7d38..bb8a5818e7f1 100644
--- a/fs/nilfs2/dat.c
+++ b/fs/nilfs2/dat.c
@@ -135,7 +135,7 @@ int nilfs_dat_prepare_start(struct inode *dat, struct nilfs_palloc_req *req)
         int ret;
 
         ret = nilfs_dat_prepare_entry(dat, req, 0);
-        BUG_ON(ret == -ENOENT);
+        WARN_ON(ret == -ENOENT);
         return ret;
 }
 
@@ -157,7 +157,6 @@ void nilfs_dat_commit_start(struct inode *dat, struct nilfs_palloc_req *req,
                        (unsigned long long)le64_to_cpu(entry->de_start),
                        (unsigned long long)le64_to_cpu(entry->de_end),
                        (unsigned long long)le64_to_cpu(entry->de_blocknr));
-                BUG();
         }
         entry->de_blocknr = cpu_to_le64(blocknr);
         kunmap_atomic(kaddr, KM_USER0);
@@ -180,7 +179,7 @@ int nilfs_dat_prepare_end(struct inode *dat, struct nilfs_palloc_req *req)
 
         ret = nilfs_dat_prepare_entry(dat, req, 0);
         if (ret < 0) {
-                BUG_ON(ret == -ENOENT);
+                WARN_ON(ret == -ENOENT);
                 return ret;
         }
 
@@ -216,7 +215,7 @@ void nilfs_dat_commit_end(struct inode *dat, struct nilfs_palloc_req *req,
         end = start = le64_to_cpu(entry->de_start);
         if (!dead) {
                 end = nilfs_mdt_cno(dat);
-                BUG_ON(start > end);
+                WARN_ON(start > end);
         }
         entry->de_end = cpu_to_le64(end);
         blocknr = le64_to_cpu(entry->de_blocknr);
@@ -324,14 +323,16 @@ int nilfs_dat_move(struct inode *dat, __u64 vblocknr, sector_t blocknr)
                 return ret;
         kaddr = kmap_atomic(entry_bh->b_page, KM_USER0);
         entry = nilfs_palloc_block_get_entry(dat, vblocknr, entry_bh, kaddr);
-        if (entry->de_blocknr == cpu_to_le64(0)) {
+        if (unlikely(entry->de_blocknr == cpu_to_le64(0))) {
                 printk(KERN_CRIT "%s: vbn = %llu, [%llu, %llu)\n", __func__,
                        (unsigned long long)vblocknr,
                        (unsigned long long)le64_to_cpu(entry->de_start),
                        (unsigned long long)le64_to_cpu(entry->de_end));
-                BUG();
+                kunmap_atomic(kaddr, KM_USER0);
+                brelse(entry_bh);
+                return -EINVAL;
         }
-        BUG_ON(blocknr == 0);
+        WARN_ON(blocknr == 0);
         entry->de_blocknr = cpu_to_le64(blocknr);
         kunmap_atomic(kaddr, KM_USER0);