ovl: treat special files like a regular fs

No sense in opening special files on the underlying layers, they work just
as well if opened on the overlay.

Side effect is that it's no longer possible to connect one side of a pipe
opened on overlayfs with the other side opened on the underlying layer.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 617b616ab03b4c1179e2c3600a64b1a8bb8c85b3..4ef0d539b09710f4a706d6fa3302473cb76c5438 100644 (file)
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -537,7 +537,7 @@ static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev,
                goto out;
 
        err = -ENOMEM;
-       inode = ovl_new_inode(dentry->d_sb, mode);
+       inode = ovl_new_inode(dentry->d_sb, mode, rdev);
        if (!inode)
                goto out_drop_write;
 

diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index a572e38349f6675bde908308510963fcff46f895..a10e948d24fab3f5f08403efaac6ed351697b2b8 100644 (file)
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -333,7 +333,7 @@ static const struct inode_operations ovl_symlink_inode_operations = {
        .update_time    = ovl_update_time,
 };
 
-static void ovl_fill_inode(struct inode *inode, umode_t mode)
+static void ovl_fill_inode(struct inode *inode, umode_t mode, dev_t rdev)
 {
        inode->i_ino = get_next_ino();
        inode->i_mode = mode;
@@ -342,8 +342,11 @@ static void ovl_fill_inode(struct inode *inode, umode_t mode)
        inode->i_acl = inode->i_default_acl = ACL_DONT_CACHE;
 #endif
 
-       mode &= S_IFMT;
-       switch (mode) {
+       switch (mode & S_IFMT) {
+       case S_IFREG:
+               inode->i_op = &ovl_file_inode_operations;
+               break;
+
        case S_IFDIR:
                inode->i_op = &ovl_dir_inode_operations;
                inode->i_fop = &ovl_dir_operations;
@@ -354,26 +357,19 @@ static void ovl_fill_inode(struct inode *inode, umode_t mode)
                break;
 
        default:
-               WARN(1, "illegal file type: %i\n", mode);
-               /* Fall through */
-
-       case S_IFREG:
-       case S_IFSOCK:
-       case S_IFBLK:
-       case S_IFCHR:
-       case S_IFIFO:
                inode->i_op = &ovl_file_inode_operations;
+               init_special_inode(inode, mode, rdev);
                break;
        }
 }
 
-struct inode *ovl_new_inode(struct super_block *sb, umode_t mode)
+struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev)
 {
        struct inode *inode;
 
        inode = new_inode(sb);
        if (inode)
-               ovl_fill_inode(inode, mode);
+               ovl_fill_inode(inode, mode, rdev);
 
        return inode;
 }
@@ -397,7 +393,7 @@ struct inode *ovl_get_inode(struct super_block *sb, struct inode *realinode)
        inode = iget5_locked(sb, (unsigned long) realinode,
                             ovl_inode_test, ovl_inode_set, realinode);
        if (inode && inode->i_state & I_NEW) {
-               ovl_fill_inode(inode, realinode->i_mode);
+               ovl_fill_inode(inode, realinode->i_mode, realinode->i_rdev);
                set_nlink(inode, realinode->i_nlink);
                unlock_new_inode(inode);
        }

diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index e218e741cb9917f52d201d8ce6738f18b03c5b60..95d0d86c2d54c2ea4474d4e8c88ca94dd79dd22c 100644 (file)
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -195,7 +195,7 @@ int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags);
 int ovl_update_time(struct inode *inode, struct timespec *ts, int flags);
 bool ovl_is_private_xattr(const char *name);
 
-struct inode *ovl_new_inode(struct super_block *sb, umode_t mode);
+struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
 struct inode *ovl_get_inode(struct super_block *sb, struct inode *realinode);
 static inline void ovl_copyattr(struct inode *from, struct inode *to)
 {

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 0e100856c7b8c252b4555b14747197fb6ee5303a..e296312005ccd3a5889ac48c984ba6dfd35ae047 100644 (file)
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -304,7 +304,7 @@ static struct dentry *ovl_d_real(struct dentry *dentry,
 {
        struct dentry *real;
 
-       if (d_is_dir(dentry)) {
+       if (!d_is_reg(dentry)) {
                if (!inode || inode == d_inode(dentry))
                        return dentry;
                goto bug;
@@ -575,7 +575,8 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
                if (upperdentry && !d_is_dir(upperdentry)) {
                        inode = ovl_get_inode(dentry->d_sb, realinode);
                } else {
-                       inode = ovl_new_inode(dentry->d_sb, realinode->i_mode);
+                       inode = ovl_new_inode(dentry->d_sb, realinode->i_mode,
+                                             realinode->i_rdev);
                        if (inode)
                                ovl_inode_init(inode, realinode, !!upperdentry);
                }
@@ -1324,7 +1325,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
        sb->s_fs_info = ufs;
        sb->s_flags |= MS_POSIXACL | MS_NOREMOTELOCK;
 
-       root_dentry = d_make_root(ovl_new_inode(sb, S_IFDIR));
+       root_dentry = d_make_root(ovl_new_inode(sb, S_IFDIR, 0));
        if (!root_dentry)
                goto out_free_oe;