ovl: rearrange copy up

Split up and rearrange copy up functions to make them better readable.

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

diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 58c06bd..15668d3 100644 (file)
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -317,6 +317,7 @@ static int ovl_set_origin(struct dentry *dentry, struct dentry *lower,
 }
 
 struct ovl_copy_up_ctx {
+       struct dentry *parent;
        struct dentry *dentry;
        struct path lowerpath;
        struct kstat stat;
@@ -493,39 +494,16 @@ out_cleanup:
  * is possible that the copy up will lock the old parent.  At that point
  * the file will have already been copied up anyway.
  */
-static int ovl_copy_up_one(struct dentry *parent, struct ovl_copy_up_ctx *c)
+static int ovl_do_copy_up(struct ovl_copy_up_ctx *c)
 {
-       DEFINE_DELAYED_CALL(done);
        int err;
-       struct path parentpath;
-       struct dentry *lowerdentry = c->lowerpath.dentry;
        struct ovl_fs *ofs = c->dentry->d_sb->s_fs_info;
 
-       c->workdir = ovl_workdir(c->dentry);
-       if (WARN_ON(!c->workdir))
-               return -EROFS;
-
-       ovl_do_check_copy_up(lowerdentry);
-
-       ovl_path_upper(parent, &parentpath);
-       c->upperdir = parentpath.dentry;
-
        /* Mark parent "impure" because it may now contain non-pure upper */
-       err = ovl_set_impure(parent, c->upperdir);
-       if (err)
-               return err;
-
-       err = vfs_getattr(&parentpath, &c->pstat,
-                         STATX_ATIME | STATX_MTIME, AT_STATX_SYNC_AS_STAT);
+       err = ovl_set_impure(c->parent, c->upperdir);
        if (err)
                return err;
 
-       if (S_ISLNK(c->stat.mode)) {
-               c->link = vfs_get_link(lowerdentry, &done);
-               if (IS_ERR(c->link))
-                       return PTR_ERR(c->link);
-       }
-
        /* Should we copyup with O_TMPFILE or with workdir? */
        if (S_ISREG(c->stat.mode) && ofs->tmpfile) {
                err = ovl_copy_up_start(c->dentry);
@@ -558,6 +536,52 @@ static int ovl_copy_up_one(struct dentry *parent, struct ovl_copy_up_ctx *c)
 out_unlock:
        unlock_rename(c->workdir, c->upperdir);
 out_done:
+
+       return err;
+}
+
+static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
+                          int flags)
+{
+       int err;
+       DEFINE_DELAYED_CALL(done);
+       struct path parentpath;
+       struct ovl_copy_up_ctx ctx = {
+               .parent = parent,
+               .dentry = dentry,
+               .workdir = ovl_workdir(dentry),
+       };
+
+       if (WARN_ON(!ctx.workdir))
+               return -EROFS;
+
+       ovl_path_lower(dentry, &ctx.lowerpath);
+       err = vfs_getattr(&ctx.lowerpath, &ctx.stat,
+                         STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
+       if (err)
+               return err;
+
+       ovl_path_upper(parent, &parentpath);
+       ctx.upperdir = parentpath.dentry;
+
+       err = vfs_getattr(&parentpath, &ctx.pstat,
+                         STATX_ATIME | STATX_MTIME, AT_STATX_SYNC_AS_STAT);
+       if (err)
+               return err;
+
+       /* maybe truncate regular file. this has no effect on dirs */
+       if (flags & O_TRUNC)
+               ctx.stat.size = 0;
+
+       if (S_ISLNK(ctx.stat.mode)) {
+               ctx.link = vfs_get_link(ctx.lowerpath.dentry, &done);
+               if (IS_ERR(ctx.link))
+                       return PTR_ERR(ctx.link);
+       }
+       ovl_do_check_copy_up(ctx.lowerpath.dentry);
+
+       err = ovl_do_copy_up(&ctx);
+
        do_delayed_call(&done);
 
        return err;
@@ -571,7 +595,6 @@ int ovl_copy_up_flags(struct dentry *dentry, int flags)
        while (!err) {
                struct dentry *next;
                struct dentry *parent;
-               struct ovl_copy_up_ctx ctx = { };
                enum ovl_path_type type = ovl_path_type(dentry);
 
                if (OVL_TYPE_UPPER(type))
@@ -590,16 +613,7 @@ int ovl_copy_up_flags(struct dentry *dentry, int flags)
                        next = parent;
                }
 
-               ovl_path_lower(next, &ctx.lowerpath);
-               err = vfs_getattr(&ctx.lowerpath, &ctx.stat,
-                                 STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
-               /* maybe truncate regular file. this has no effect on dirs */
-               if (flags & O_TRUNC)
-                       ctx.stat.size = 0;
-               if (!err) {
-                       ctx.dentry = next;
-                       err = ovl_copy_up_one(parent, &ctx);
-               }
+               err = ovl_copy_up_one(parent, next, flags);
 
                dput(parent);
                dput(next);