ovl: support [S|G]ETFLAGS and FS[S|G]ETXATTR ioctls for directories

[S|G]ETFLAGS and FS[S|G]ETXATTR ioctls are applicable to both files and
directories, so add ioctl operations to dir as well.

We teach ovl_real_fdget() to get the realfile of directories which use
a different type of file->private_data.

Ifdef away compat ioctl implementation to conform to standard practice.

With this change, xfstest generic/079 which tests these ioctls on files
and directories passes.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index 3582c3a..443986c 100644 (file)
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -136,6 +136,13 @@ static int ovl_real_fdget_meta(const struct file *file, struct fd *real,
 
 static int ovl_real_fdget(const struct file *file, struct fd *real)
 {
+       if (d_is_dir(file_dentry(file))) {
+               real->flags = 0;
+               real->file = ovl_dir_real_file(file, false);
+
+               return PTR_ERR_OR_ZERO(real->file);
+       }
+
        return ovl_real_fdget_meta(file, real, false);
 }
 
@@ -648,7 +655,7 @@ static long ovl_ioctl_set_fsxflags(struct file *file, unsigned int cmd,
                                   ovl_fsxflags_to_iflags(fa.fsx_xflags));
 }
 
-static long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
        long ret;
 
@@ -673,8 +680,8 @@ static long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
        return ret;
 }
 
-static long ovl_compat_ioctl(struct file *file, unsigned int cmd,
-                            unsigned long arg)
+#ifdef CONFIG_COMPAT
+long ovl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
        switch (cmd) {
        case FS_IOC32_GETFLAGS:
@@ -691,6 +698,7 @@ static long ovl_compat_ioctl(struct file *file, unsigned int cmd,
 
        return ovl_ioctl(file, cmd, arg);
 }
+#endif
 
 enum ovl_copyop {
        OVL_COPY,
@@ -792,7 +800,9 @@ const struct file_operations ovl_file_operations = {
        .fallocate      = ovl_fallocate,
        .fadvise        = ovl_fadvise,
        .unlocked_ioctl = ovl_ioctl,
+#ifdef CONFIG_COMPAT
        .compat_ioctl   = ovl_compat_ioctl,
+#endif
        .splice_read    = ovl_splice_read,
        .splice_write   = ovl_splice_write,
 

diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 7bce246..f8880aa 100644 (file)
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -416,6 +416,7 @@ static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index,
 
 /* readdir.c */
 extern const struct file_operations ovl_dir_operations;
+struct file *ovl_dir_real_file(const struct file *file, bool want_upper);
 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
 void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
 void ovl_cache_free(struct list_head *list);
@@ -503,6 +504,8 @@ struct dentry *ovl_create_temp(struct dentry *workdir, struct ovl_cattr *attr);
 extern const struct file_operations ovl_file_operations;
 int __init ovl_aio_request_cache_init(void);
 void ovl_aio_request_cache_destroy(void);
+long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
+long ovl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 
 /* copy_up.c */
 int ovl_copy_up(struct dentry *dentry);

diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 5960020..01620eb 100644 (file)
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -840,7 +840,7 @@ out_unlock:
        return res;
 }
 
-static struct file *ovl_dir_open_realfile(struct file *file,
+static struct file *ovl_dir_open_realfile(const struct file *file,
                                          struct path *realpath)
 {
        struct file *res;
@@ -853,19 +853,22 @@ static struct file *ovl_dir_open_realfile(struct file *file,
        return res;
 }
 
-static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
-                        int datasync)
+/*
+ * Like ovl_real_fdget(), returns upperfile if dir was copied up since open.
+ * Unlike ovl_real_fdget(), this caches upperfile in file->private_data.
+ *
+ * TODO: use same abstract type for file->private_data of dir and file so
+ * upperfile could also be cached for files as well.
+ */
+struct file *ovl_dir_real_file(const struct file *file, bool want_upper)
 {
+
        struct ovl_dir_file *od = file->private_data;
        struct dentry *dentry = file->f_path.dentry;
        struct file *realfile = od->realfile;
 
-       /* Nothing to sync for lower */
        if (!OVL_TYPE_UPPER(ovl_path_type(dentry)))
-               return 0;
-
-       if (!ovl_should_sync(OVL_FS(dentry->d_sb)))
-               return 0;
+               return want_upper ? NULL : realfile;
 
        /*
         * Need to check if we started out being a lower dir, but got copied up
@@ -884,7 +887,7 @@ static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
                        if (!od->upperfile) {
                                if (IS_ERR(realfile)) {
                                        inode_unlock(inode);
-                                       return PTR_ERR(realfile);
+                                       return realfile;
                                }
                                smp_store_release(&od->upperfile, realfile);
                        } else {
@@ -897,6 +900,25 @@ static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
                }
        }
 
+       return realfile;
+}
+
+static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
+                        int datasync)
+{
+       struct file *realfile;
+       int err;
+
+       if (!ovl_should_sync(OVL_FS(file->f_path.dentry->d_sb)))
+               return 0;
+
+       realfile = ovl_dir_real_file(file, true);
+       err = PTR_ERR_OR_ZERO(realfile);
+
+       /* Nothing to sync for lower */
+       if (!realfile || err)
+               return err;
+
        return vfs_fsync_range(realfile, start, end, datasync);
 }
 
@@ -949,6 +971,10 @@ const struct file_operations ovl_dir_operations = {
        .llseek         = ovl_dir_llseek,
        .fsync          = ovl_dir_fsync,
        .release        = ovl_dir_release,
+       .unlocked_ioctl = ovl_ioctl,
+#ifdef CONFIG_COMPAT
+       .compat_ioctl   = ovl_compat_ioctl,
+#endif
 };
 
 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list)