When file system is mounted read-only workdir is not needed.
Signed-off-by: Seunghun Lee <way...@gmail.com>
---
fs/overlayfs/super.c | 35 +++++++++++++++++++++++------------
1 file changed, 23 insertions(+), 12 deletions(-)
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 84f3144..4e50617 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -30,6 +30,7 @@ struct ovl_config {
char *lowerdir;
char *upperdir;
char *workdir;
+ bool is_rw;
};
/* private information held for overlayfs's superblock */
@@ -515,10 +516,11 @@ 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);
- if (ufs->config.upperdir) {
+ if (ufs->config.upperdir)
seq_printf(m, ",upperdir=%s", ufs->config.upperdir);
+ if (ufs->config.is_rw)
seq_printf(m, ",workdir=%s", ufs->config.workdir);
- }
+
return 0;
}
@@ -822,16 +824,27 @@ 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 */
+ err = ovl_mount_dir(ufs->config.upperdir, &upperpath);
+ if (err)
+ goto out_free_config;
+
+ sb->s_stack_depth = upperpath.mnt->mnt_sb->s_stack_depth;
+ }
+
+ /* If the upper fs is r/o or nonexistent, we mark overlayfs r/o too */
+ if (!upperpath.mnt || (upperpath.mnt->mnt_sb->s_flags & MS_RDONLY)) {
+ ufs->config.is_rw = false;
+ sb->s_flags |= MS_RDONLY;
+ } else {
+ ufs->config.is_rw = true;
+ }
+
+ if (ufs->config.is_rw) {
if (!ufs->config.workdir) {
pr_err("overlayfs: missing 'workdir'\n");
goto out_free_config;
}
- err = ovl_mount_dir(ufs->config.upperdir, &upperpath);
- if (err)
- goto out_free_config;
-
err = ovl_mount_dir(ufs->config.workdir, &workpath);
if (err)
goto out_put_upperpath;
@@ -844,8 +857,8 @@ static int ovl_fill_super(struct super_block *sb, void
*data, int silent)
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;
}
+
err = -ENOMEM;
lowertmp = kstrdup(ufs->config.lowerdir, GFP_KERNEL);
if (!lowertmp)
@@ -884,7 +897,9 @@ static int ovl_fill_super(struct super_block *sb, void
*data, int silent)
pr_err("overlayfs: failed to clone upperpath\n");
goto out_put_lowerpath;
}
+ }
+ if (ufs->config.is_rw) {
ufs->workdir = ovl_workdir_create(ufs->upper_mnt,
workpath.dentry);
err = PTR_ERR(ufs->workdir);
if (IS_ERR(ufs->workdir)) {
@@ -914,10 +929,6 @@ 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))
- sb->s_flags |= MS_RDONLY;
-
sb->s_d_op = &ovl_dentry_operations;
err = -ENOMEM;
--
2.2.1
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