diff options
Diffstat (limited to 'fs/overlayfs')
| -rw-r--r-- | fs/overlayfs/super.c | 33 |
1 files changed, 27 insertions, 6 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index b90952f528b1..5f0d1993e6e3 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -529,8 +529,7 @@ static int ovl_remount(struct super_block *sb, int *flags, char *data) { struct ovl_fs *ufs = sb->s_fs_info; - if (!(*flags & MS_RDONLY) && - (!ufs->upper_mnt || (ufs->upper_mnt->mnt_sb->s_flags & MS_RDONLY))) + if (!(*flags & MS_RDONLY) && !ufs->upper_mnt) return -EROFS; return 0; @@ -615,9 +614,19 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config) break; default: + pr_err("overlayfs: unrecognized mount option \"%s\" or missing value\n", p); return -EINVAL; } } + + /* Workdir is useless in non-upper mount */ + if (!config->upperdir && config->workdir) { + pr_info("overlayfs: option \"workdir=%s\" is useless in a non-upper mount, ignore\n", + config->workdir); + kfree(config->workdir); + config->workdir = NULL; + } + return 0; } @@ -837,7 +846,6 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) 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; @@ -847,6 +855,13 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) if (err) goto out_free_config; + /* Upper fs should not be r/o */ + if (upperpath.mnt->mnt_sb->s_flags & MS_RDONLY) { + pr_err("overlayfs: upper fs is r/o, try multi-lower layers mount\n"); + err = -EINVAL; + goto out_put_upperpath; + } + err = ovl_mount_dir(ufs->config.workdir, &workpath); if (err) goto out_put_upperpath; @@ -869,8 +884,14 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) err = -EINVAL; stacklen = ovl_split_lowerdirs(lowertmp); - if (stacklen > OVL_MAX_STACK) + if (stacklen > OVL_MAX_STACK) { + pr_err("overlayfs: too many lower directries, limit is %d\n", + OVL_MAX_STACK); goto out_free_lowertmp; + } else if (!ufs->config.upperdir && stacklen == 1) { + pr_err("overlayfs: at least 2 lowerdir are needed while upperdir nonexistent\n"); + goto out_free_lowertmp; + } stack = kcalloc(stacklen, sizeof(struct path), GFP_KERNEL); if (!stack) @@ -932,8 +953,8 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) ufs->numlower++; } - /* 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)) + /* If the upper fs is nonexistent, we mark overlayfs r/o too */ + if (!ufs->upper_mnt) sb->s_flags |= MS_RDONLY; sb->s_d_op = &ovl_dentry_operations; |