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>
diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index cfb2789..108d281 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -489,14 +489,14 @@
ret = nilfs_mdt_mark_block_dirty(dat,
bdescs[i].bd_offset);
if (ret < 0) {
- BUG_ON(ret == -ENOENT);
+ WARN_ON(ret == -ENOENT);
return ret;
}
} else {
ret = nilfs_bmap_mark(bmap, bdescs[i].bd_offset,
bdescs[i].bd_level);
if (ret < 0) {
- BUG_ON(ret == -ENOENT);
+ WARN_ON(ret == -ENOENT);
return ret;
}
}
@@ -519,7 +519,8 @@
struct nilfs_sb_info *sbi = nilfs_get_writer(nilfs);
int ret;
- BUG_ON(!sbi);
+ if (unlikely(!sbi))
+ return -EROFS;
ret = nilfs_segctor_add_segments_to_be_freed(
NILFS_SC(sbi), buf, nmembs);
nilfs_put_writer(nilfs);
@@ -539,6 +540,7 @@
void __user *argp)
{
struct nilfs_argv argv[5];
+ const char *msg;
int dir, ret;
if (copy_from_user(argv, argp, sizeof(argv)))
@@ -546,31 +548,50 @@
dir = _IOC_WRITE;
ret = nilfs_ioctl_move_blocks(nilfs, &argv[0], dir);
- if (ret < 0)
- goto out_move_blks;
+ if (ret < 0) {
+ msg = "cannot read source blocks";
+ goto failed;
+ }
ret = nilfs_ioctl_delete_checkpoints(nilfs, &argv[1], dir);
- if (ret < 0)
- goto out_del_cps;
+ if (ret < 0) {
+ /*
+ * can safely abort because checkpoints can be removed
+ * independently.
+ */
+ msg = "cannot delete checkpoints";
+ goto failed;
+ }
ret = nilfs_ioctl_free_vblocknrs(nilfs, &argv[2], dir);
- if (ret < 0)
- goto out_free_vbns;
+ if (ret < 0) {
+ /*
+ * can safely abort because DAT file is updated atomically
+ * using a copy-on-write technique.
+ */
+ msg = "cannot delete virtual blocks from DAT file";
+ goto failed;
+ }
ret = nilfs_ioctl_mark_blocks_dirty(nilfs, &argv[3], dir);
- if (ret < 0)
- goto out_free_vbns;
+ if (ret < 0) {
+ /*
+ * can safely abort because the operation is nondestructive.
+ */
+ msg = "cannot mark copying blocks dirty";
+ goto failed;
+ }
ret = nilfs_ioctl_free_segments(nilfs, &argv[4], dir);
- if (ret < 0)
- goto out_free_segs;
-
+ if (ret < 0) {
+ /*
+ * can safely abort because this operation is atomic.
+ */
+ msg = "cannot set segments to be freed";
+ goto failed;
+ }
return 0;
- out_free_segs:
- BUG(); /* XXX: not implemented yet */
- out_free_vbns:
- BUG();/* XXX: not implemented yet */
- out_del_cps:
- BUG();/* XXX: not implemented yet */
- out_move_blks:
+ failed:
nilfs_remove_all_gcinode(nilfs);
+ printk(KERN_ERR "NILFS: GC failed during preparation: %s: err=%d\n",
+ msg, ret);
return ret;
}