diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/overlayfs/super.c | 83 |
1 files changed, 47 insertions, 36 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 592370f..35bb0ad 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -516,8 +516,10 @@ static int ovl_show_options(struct seq_file *m, struct dentry *dentry) struct ovl_fs *ufs = sb->s_fs_info; seq_printf(m, ",lowerdir=%s", ufs->config.lowerdir); - seq_printf(m, ",upperdir=%s", ufs->config.upperdir); - seq_printf(m, ",workdir=%s", ufs->config.workdir); + if (ufs->config.upperdir) { + seq_printf(m, ",upperdir=%s", ufs->config.upperdir); + seq_printf(m, ",workdir=%s", ufs->config.workdir); + } return 0; } @@ -768,8 +770,8 @@ static bool ovl_workdir_ok(struct dentry *workdir, struct dentry *upperdir) static int ovl_fill_super(struct super_block *sb, void *data, int silent) { struct path lowerpath; - struct path upperpath; - struct path workpath; + struct path upperpath = { NULL, NULL }; + struct path workpath = { NULL, NULL }; struct dentry *root_dentry; struct ovl_entry *oe; struct ovl_fs *ufs; @@ -786,31 +788,38 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) if (err) goto out_free_config; - /* FIXME: workdir is not needed for a R/O mount */ err = -EINVAL; - if (!ufs->config.upperdir || !ufs->config.lowerdir || - !ufs->config.workdir) { - pr_err("overlayfs: missing upperdir or lowerdir or workdir\n"); + if (!ufs->config.lowerdir) { + pr_err("overlayfs: missing 'lowerdir'\n"); goto out_free_config; } - err = ovl_mount_dir(ufs->config.upperdir, &upperpath); - if (err) - goto out_free_config; + sb->s_stack_depth = 0; + if (ufs->config.upperdir) { + /* FIXME: workdir is not needed for a R/O mount */ + if (!ufs->config.workdir) { + pr_err("overlayfs: missing 'workdir'\n"); + goto out_free_config; + } - err = ovl_mount_dir(ufs->config.workdir, &workpath); - if (err) - goto out_put_upperpath; + err = ovl_mount_dir(ufs->config.upperdir, &upperpath); + if (err) + goto out_free_config; - if (upperpath.mnt != workpath.mnt) { - pr_err("overlayfs: workdir and upperdir must reside under the same mount\n"); - goto out_put_workpath; - } - if (!ovl_workdir_ok(workpath.dentry, upperpath.dentry)) { - pr_err("overlayfs: workdir and upperdir must be separate subtrees\n"); - goto out_put_workpath; + err = ovl_mount_dir(ufs->config.workdir, &workpath); + if (err) + goto out_put_upperpath; + + if (upperpath.mnt != workpath.mnt) { + pr_err("overlayfs: workdir and upperdir must reside under the same mount\n"); + goto out_put_workpath; + } + if (!ovl_workdir_ok(workpath.dentry, upperpath.dentry)) { + pr_err("overlayfs: workdir and upperdir must be separate subtrees\n"); + goto out_put_workpath; + } + sb->s_stack_depth = upperpath.mnt->mnt_sb->s_stack_depth; } - sb->s_stack_depth = upperpath.mnt->mnt_sb->s_stack_depth; err = ovl_lower_dir(ufs->config.lowerdir, &lowerpath, &ufs->lower_namelen, &sb->s_stack_depth); @@ -824,19 +833,21 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) goto out_put_lowerpath; } - ufs->upper_mnt = clone_private_mount(&upperpath); - err = PTR_ERR(ufs->upper_mnt); - if (IS_ERR(ufs->upper_mnt)) { - pr_err("overlayfs: failed to clone upperpath\n"); - goto out_put_lowerpath; - } + if (ufs->config.upperdir) { + ufs->upper_mnt = clone_private_mount(&upperpath); + err = PTR_ERR(ufs->upper_mnt); + if (IS_ERR(ufs->upper_mnt)) { + pr_err("overlayfs: failed to clone upperpath\n"); + goto out_put_lowerpath; + } - ufs->workdir = ovl_workdir_create(ufs->upper_mnt, workpath.dentry); - err = PTR_ERR(ufs->workdir); - if (IS_ERR(ufs->workdir)) { - pr_err("overlayfs: failed to create directory %s/%s\n", - ufs->config.workdir, OVL_WORKDIR_NAME); - goto out_put_upper_mnt; + ufs->workdir = ovl_workdir_create(ufs->upper_mnt, workpath.dentry); + err = PTR_ERR(ufs->workdir); + if (IS_ERR(ufs->workdir)) { + pr_err("overlayfs: failed to create directory %s/%s\n", + ufs->config.workdir, OVL_WORKDIR_NAME); + goto out_put_upper_mnt; + } } ufs->lower_mnt = kcalloc(1, sizeof(struct vfsmount *), GFP_KERNEL); @@ -858,8 +869,8 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) ufs->lower_mnt[0] = mnt; ufs->numlower = 1; - /* If the upper fs is r/o, we mark overlayfs r/o too */ - if (ufs->upper_mnt->mnt_sb->s_flags & MS_RDONLY) + /* If the upper fs is r/o or nonexistent, we mark overlayfs r/o too */ + if (!ufs->upper_mnt || (ufs->upper_mnt->mnt_sb->s_flags & MS_RDONLY)) sb->s_flags |= MS_RDONLY; sb->s_d_op = &ovl_dentry_operations; |
