From: Amir Goldstein amir73il@gmail.com
mainline inclusion from mainline-v5.7-rc1 commit 4d314f7859dc1925ee28b4d4e74f6f3a80e6f34b category: bugfix bugzilla: NA CVE: NA
-------------------------------------------------
There is no reason to deplete the system's global get_next_ino() pool for overlay non-persistent inode numbers and there is no reason at all to allocate non-persistent inode numbers for non-directories.
For non-directories, it is much better to leave i_ino the same as real i_ino, to be consistent with st_ino/d_ino.
Signed-off-by: Amir Goldstein amir73il@gmail.com Signed-off-by: Miklos Szeredi mszeredi@redhat.com Signed-off-by: Zheng Liang zhengliang6@huawei.com Reviewed-by: Zhang Yi yi.zhang@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- fs/overlayfs/inode.c | 15 ++++++++++++--- fs/overlayfs/ovl_entry.h | 2 ++ fs/overlayfs/super.c | 1 + 3 files changed, 15 insertions(+), 3 deletions(-)
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 4ff4198a0ad44..b721387f7f1e1 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -545,6 +545,15 @@ static inline void ovl_lockdep_annotate_inode_mutex_key(struct inode *inode) #endif }
+static void ovl_next_ino(struct inode *inode) +{ + struct ovl_fs *ofs = inode->i_sb->s_fs_info; + + inode->i_ino = atomic_long_inc_return(&ofs->last_ino); + if (unlikely(!inode->i_ino)) + inode->i_ino = atomic_long_inc_return(&ofs->last_ino); +} + static void ovl_map_ino(struct inode *inode, unsigned long ino, int fsid) { int xinobits = ovl_xino_bits(inode->i_sb); @@ -556,12 +565,12 @@ static void ovl_map_ino(struct inode *inode, unsigned long ino, int fsid) * consistent with d_ino and st_ino values. An i_ino value inconsistent * with d_ino also causes nfsd readdirplus to fail. */ + inode->i_ino = ino; if (ovl_same_dev(inode->i_sb)) { - inode->i_ino = ino; if (xinobits && fsid && !(ino >> (64 - xinobits))) inode->i_ino |= (unsigned long)fsid << (64 - xinobits); - } else { - inode->i_ino = get_next_ino(); + } else if (S_ISDIR(inode->i_mode)) { + ovl_next_ino(inode); } }
diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h index ae09310f5a6fe..30523cc7b914b 100644 --- a/fs/overlayfs/ovl_entry.h +++ b/fs/overlayfs/ovl_entry.h @@ -78,6 +78,8 @@ struct ovl_fs { struct inode *indexdir_trap; /* -1: disabled, 0: same fs, 1..32: number of unused ino bits */ int xino_mode; + /* For allocation of non-persistent inode numbers */ + atomic_long_t last_ino; };
static inline struct ovl_fs *OVL_FS(struct super_block *sb) diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 1f9a717fdad55..20c20f6210a5f 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -1677,6 +1677,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
sb->s_stack_depth = 0; sb->s_maxbytes = MAX_LFS_FILESIZE; + atomic_long_set(&ofs->last_ino, 1); /* Assume underlaying fs uses 32bit inodes unless proven otherwise */ if (ofs->config.xino != OVL_XINO_OFF) { ofs->xino_mode = BITS_PER_LONG - 32;