diff options
| -rw-r--r-- | fs/overlayfs/overlayfs.h | 1 | ||||
| -rw-r--r-- | fs/overlayfs/ovl_entry.h | 2 | ||||
| -rw-r--r-- | fs/overlayfs/super.c | 8 | ||||
| -rw-r--r-- | fs/overlayfs/util.c | 7 |
4 files changed, 18 insertions, 0 deletions
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 741dc0b6931f..c851158324e2 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -151,6 +151,7 @@ int ovl_want_write(struct dentry *dentry); void ovl_drop_write(struct dentry *dentry); struct dentry *ovl_workdir(struct dentry *dentry); const struct cred *ovl_override_creds(struct super_block *sb); +struct super_block *ovl_same_sb(struct super_block *sb); struct ovl_entry *ovl_alloc_entry(unsigned int numlower); bool ovl_dentry_remote(struct dentry *dentry); bool ovl_dentry_weird(struct dentry *dentry); diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h index 59614faa14c3..b2023ddb8532 100644 --- a/fs/overlayfs/ovl_entry.h +++ b/fs/overlayfs/ovl_entry.h @@ -29,6 +29,8 @@ struct ovl_fs { const struct cred *creator_cred; bool tmpfile; wait_queue_head_t copyup_wq; + /* sb common to all layers */ + struct super_block *same_sb; }; /* private information held for every overlayfs dentry */ diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 6faefa54cb5e..9828b7de8999 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -914,11 +914,19 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) ufs->lower_mnt[ufs->numlower] = mnt; ufs->numlower++; + + /* Check if all lower layers are on same sb */ + if (i == 0) + ufs->same_sb = mnt->mnt_sb; + else if (ufs->same_sb != mnt->mnt_sb) + ufs->same_sb = NULL; } /* If the upper fs is nonexistent, we mark overlayfs r/o too */ if (!ufs->upper_mnt) sb->s_flags |= MS_RDONLY; + else if (ufs->upper_mnt->mnt_sb != ufs->same_sb) + ufs->same_sb = NULL; if (remote) sb->s_d_op = &ovl_reval_dentry_operations; diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index 35b8959db5ee..2bd4c264ccbe 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -41,6 +41,13 @@ const struct cred *ovl_override_creds(struct super_block *sb) return override_creds(ofs->creator_cred); } +struct super_block *ovl_same_sb(struct super_block *sb) +{ + struct ovl_fs *ofs = sb->s_fs_info; + + return ofs->same_sb; +} + struct ovl_entry *ovl_alloc_entry(unsigned int numlower) { size_t size = offsetof(struct ovl_entry, lowerstack[numlower]); |