[PATCH v2 3/4] f2fs: handle error of f2fs_iget correctly

From: Chao Yu
Date: Fri Aug 07 2015 - 05:58:43 EST


In recover_orphan_inode, whenever f2fs_iget fail, we will make kernel panic,
but it's not reasonable, because f2fs_iget can fail due to a lot of reasons
including out of memory.

So we change error handling method as below:
a) when finding no entry for the orphan inode, bug_on for catching bugs;
b) for other reasons, report it to caller.

Signed-off-by: Chao Yu <chao2.yu@xxxxxxxxxxx>
---
fs/f2fs/checkpoint.c | 31 ++++++++++++++++++++++++-------
fs/f2fs/f2fs.h | 2 +-
fs/f2fs/super.c | 4 +++-
3 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index c311176..0958c83 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -468,22 +468,34 @@ void remove_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino)
__remove_ino_entry(sbi, ino, ORPHAN_INO);
}

-static void recover_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino)
+static int recover_orphan_inode(struct f2fs_sb_info *sbi, nid_t ino)
{
- struct inode *inode = f2fs_iget(sbi->sb, ino);
- f2fs_bug_on(sbi, IS_ERR(inode));
+ struct inode *inode;
+
+ inode = f2fs_iget(sbi->sb, ino);
+ if (IS_ERR(inode)) {
+ /*
+ * there should be a bug that we can't find the entry
+ * to orphan inode.
+ */
+ f2fs_bug_on(sbi, PTR_ERR(inode) == -ENOENT);
+ return PTR_ERR(inode);
+ }
+
clear_nlink(inode);

/* truncate all the data during iput */
iput(inode);
+ return 0;
}

-void recover_orphan_inodes(struct f2fs_sb_info *sbi)
+int recover_orphan_inodes(struct f2fs_sb_info *sbi)
{
block_t start_blk, orphan_blocks, i, j;
+ int err;

if (!is_set_ckpt_flags(F2FS_CKPT(sbi), CP_ORPHAN_PRESENT_FLAG))
- return;
+ return 0;

set_sbi_flag(sbi, SBI_POR_DOING);

@@ -499,14 +511,19 @@ void recover_orphan_inodes(struct f2fs_sb_info *sbi)
orphan_blk = (struct f2fs_orphan_block *)page_address(page);
for (j = 0; j < le32_to_cpu(orphan_blk->entry_count); j++) {
nid_t ino = le32_to_cpu(orphan_blk->ino[j]);
- recover_orphan_inode(sbi, ino);
+ err = recover_orphan_inode(sbi, ino);
+ if (err) {
+ f2fs_put_page(page, 1);
+ clear_sbi_flag(sbi, SBI_POR_DOING);
+ return err;
+ }
}
f2fs_put_page(page, 1);
}
/* clear Orphan Flag */
clear_ckpt_flags(F2FS_CKPT(sbi), CP_ORPHAN_PRESENT_FLAG);
clear_sbi_flag(sbi, SBI_POR_DOING);
- return;
+ return 0;
}

static void write_orphan_inodes(struct f2fs_sb_info *sbi, block_t start_blk)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index f18d31e..d0e9b70 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1748,7 +1748,7 @@ int acquire_orphan_inode(struct f2fs_sb_info *);
void release_orphan_inode(struct f2fs_sb_info *);
void add_orphan_inode(struct f2fs_sb_info *, nid_t);
void remove_orphan_inode(struct f2fs_sb_info *, nid_t);
-void recover_orphan_inodes(struct f2fs_sb_info *);
+int recover_orphan_inodes(struct f2fs_sb_info *);
int get_valid_checkpoint(struct f2fs_sb_info *);
void update_dirty_page(struct inode *, struct page *);
void add_dirty_dir_inode(struct inode *);
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index a79b6b5..4db5cd9 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1245,7 +1245,9 @@ try_onemore:
f2fs_join_shrinker(sbi);

/* if there are nt orphan nodes free them */
- recover_orphan_inodes(sbi);
+ err = recover_orphan_inodes(sbi);
+ if (err)
+ goto free_node_inode;

/* read root inode and dentry */
root = f2fs_iget(sb, F2FS_ROOT_INO(sbi));
--
2.4.2


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