[PATCH 4/5] ext4: use EXT4_BAD_INO for buddy cache to avoid colliding with valid inode #
From: Theodore Ts'o <tytso@mit.edu>
Date: 2011-08-01 13:13:21
Subsystem:
ext4 file system, filesystems (vfs and infrastructure), the rest · Maintainers:
"Theodore Ts'o", Alexander Viro, Christian Brauner, Linus Torvalds
From: Yu Jian <redacted> Signed-off-by: Yu Jian <redacted> Signed-off-by: Andreas Dilger <redacted> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> --- fs/ext4/mballoc.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 262fa47..8beccd8 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c@@ -2342,7 +2342,11 @@ static int ext4_mb_init_backend(struct super_block *sb) ext4_msg(sb, KERN_ERR, "can't get new inode"); goto err_freesgi; } - sbi->s_buddy_cache->i_ino = get_next_ino(); + /* To avoid potentially colliding with an valid on-disk inode number, + * use EXT4_BAD_INO for the buddy cache inode number. This inode is + * not in the inode hash, so it should never be found by iget(), but + * this will avoid confusion if it ever shows up during debugging. */ + sbi->s_buddy_cache->i_ino = EXT4_BAD_INO; EXT4_I(sbi->s_buddy_cache)->i_disksize = 0; for (i = 0; i < ngroups; i++) { desc = ext4_get_group_desc(sb, i, NULL);
--
1.7.4.1.22.gec8e1.dirty