summaryrefslogtreecommitdiffstats
path: root/fs/overlayfs/super.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/overlayfs/super.c')
-rw-r--r--fs/overlayfs/super.c117
1 files changed, 99 insertions, 18 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 4b38141c2985..290983bcfbb3 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -264,6 +264,8 @@ static int ovl_sync_fs(struct super_block *sb, int wait)
if (!ovl_upper_mnt(ofs))
return 0;
+ if (!ovl_should_sync(ofs))
+ return 0;
/*
* Not called for sync(2) call or an emergency sync (SB_I_SKIP_SYNC).
* All the super blocks will be iterated, including upper_sb.
@@ -362,6 +364,8 @@ static int ovl_show_options(struct seq_file *m, struct dentry *dentry)
if (ofs->config.metacopy != ovl_metacopy_def)
seq_printf(m, ",metacopy=%s",
ofs->config.metacopy ? "on" : "off");
+ if (ofs->config.ovl_volatile)
+ seq_puts(m, ",volatile");
return 0;
}
@@ -376,9 +380,11 @@ static int ovl_remount(struct super_block *sb, int *flags, char *data)
if (*flags & SB_RDONLY && !sb_rdonly(sb)) {
upper_sb = ovl_upper_mnt(ofs)->mnt_sb;
- down_read(&upper_sb->s_umount);
- ret = sync_filesystem(upper_sb);
- up_read(&upper_sb->s_umount);
+ if (ovl_should_sync(ofs)) {
+ down_read(&upper_sb->s_umount);
+ ret = sync_filesystem(upper_sb);
+ up_read(&upper_sb->s_umount);
+ }
}
return ret;
@@ -411,6 +417,7 @@ enum {
OPT_XINO_AUTO,
OPT_METACOPY_ON,
OPT_METACOPY_OFF,
+ OPT_VOLATILE,
OPT_ERR,
};
@@ -429,6 +436,7 @@ static const match_table_t ovl_tokens = {
{OPT_XINO_AUTO, "xino=auto"},
{OPT_METACOPY_ON, "metacopy=on"},
{OPT_METACOPY_OFF, "metacopy=off"},
+ {OPT_VOLATILE, "volatile"},
{OPT_ERR, NULL}
};
@@ -573,6 +581,10 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config)
metacopy_opt = true;
break;
+ case OPT_VOLATILE:
+ config->ovl_volatile = true;
+ break;
+
default:
pr_err("unrecognized mount option \"%s\" or missing value\n",
p);
@@ -595,6 +607,11 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config)
config->index = false;
}
+ if (!config->upperdir && config->ovl_volatile) {
+ pr_info("option \"volatile\" is meaningless in a non-upper mount, ignoring it.\n");
+ config->ovl_volatile = false;
+ }
+
err = ovl_parse_redirect_mode(config, config->redirect_mode);
if (err)
return err;
@@ -705,8 +722,12 @@ retry:
goto out_unlock;
retried = true;
- ovl_workdir_cleanup(dir, mnt, work, 0);
+ err = ovl_workdir_cleanup(dir, mnt, work, 0);
dput(work);
+ if (err == -EINVAL) {
+ work = ERR_PTR(err);
+ goto out_unlock;
+ }
goto retry;
}
@@ -1199,11 +1220,50 @@ out_unlock:
return err;
}
+static struct dentry *ovl_lookup_or_create(struct dentry *parent,
+ const char *name, umode_t mode)
+{
+ size_t len = strlen(name);
+ struct dentry *child;
+
+ inode_lock_nested(parent->d_inode, I_MUTEX_PARENT);
+ child = lookup_one_len(name, parent, len);
+ if (!IS_ERR(child) && !child->d_inode)
+ child = ovl_create_real(parent->d_inode, child,
+ OVL_CATTR(mode));
+ inode_unlock(parent->d_inode);
+ dput(parent);
+
+ return child;
+}
+
+/*
+ * Creates $workdir/work/incompat/volatile/dirty file if it is not already
+ * present.
+ */
+static int ovl_create_volatile_dirty(struct ovl_fs *ofs)
+{
+ unsigned int ctr;
+ struct dentry *d = dget(ofs->workbasedir);
+ static const char *const volatile_path[] = {
+ OVL_WORKDIR_NAME, "incompat", "volatile", "dirty"
+ };
+ const char *const *name = volatile_path;
+
+ for (ctr = ARRAY_SIZE(volatile_path); ctr; ctr--, name++) {
+ d = ovl_lookup_or_create(d, *name, ctr > 1 ? S_IFDIR : S_IFREG);
+ if (IS_ERR(d))
+ return PTR_ERR(d);
+ }
+ dput(d);
+ return 0;
+}
+
static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
struct path *workpath)
{
struct vfsmount *mnt = ovl_upper_mnt(ofs);
- struct dentry *temp;
+ struct dentry *temp, *workdir;
bool rename_whiteout;
bool d_type;
int fh_type;
@@ -1213,10 +1273,13 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
if (err)
return err;
- ofs->workdir = ovl_workdir_create(ofs, OVL_WORKDIR_NAME, false);
- if (!ofs->workdir)
+ workdir = ovl_workdir_create(ofs, OVL_WORKDIR_NAME, false);
+ err = PTR_ERR(workdir);
+ if (IS_ERR_OR_NULL(workdir))
goto out;
+ ofs->workdir = workdir;
+
err = ovl_setup_trap(sb, ofs->workdir, &ofs->workdir_trap, "workdir");
if (err)
goto out;
@@ -1256,7 +1319,7 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
/*
* Check if upper/work fs supports trusted.overlay.* xattr
*/
- err = ovl_do_setxattr(ofs->workdir, OVL_XATTR_OPAQUE, "0", 1, 0);
+ err = ovl_do_setxattr(ofs, ofs->workdir, OVL_XATTR_OPAQUE, "0", 1);
if (err) {
ofs->noxattr = true;
ofs->config.index = false;
@@ -1264,7 +1327,7 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
pr_warn("upper fs does not support xattr, falling back to index=off and metacopy=off.\n");
err = 0;
} else {
- vfs_removexattr(ofs->workdir, OVL_XATTR_OPAQUE);
+ ovl_do_removexattr(ofs, ofs->workdir, OVL_XATTR_OPAQUE);
}
/*
@@ -1279,6 +1342,18 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
goto out;
}
+ /*
+ * For volatile mount, create a incompat/volatile/dirty file to keep
+ * track of it.
+ */
+ if (ofs->config.ovl_volatile) {
+ err = ovl_create_volatile_dirty(ofs);
+ if (err < 0) {
+ pr_err("Failed to create volatile/dirty file.\n");
+ goto out;
+ }
+ }
+
/* Check if upper/work fs supports file handles */
fh_type = ovl_can_decode_fh(ofs->workdir->d_sb);
if (ofs->config.index && !fh_type) {
@@ -1347,6 +1422,7 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs,
struct ovl_entry *oe, struct path *upperpath)
{
struct vfsmount *mnt = ovl_upper_mnt(ofs);
+ struct dentry *indexdir;
int err;
err = mnt_want_write(mnt);
@@ -1354,8 +1430,8 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs,
return err;
/* Verify lower root is upper root origin */
- err = ovl_verify_origin(upperpath->dentry, oe->lowerstack[0].dentry,
- true);
+ err = ovl_verify_origin(ofs, upperpath->dentry,
+ oe->lowerstack[0].dentry, true);
if (err) {
pr_err("failed to verify upper root origin\n");
goto out;
@@ -1366,9 +1442,12 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs,
ofs->workdir_trap = NULL;
dput(ofs->workdir);
ofs->workdir = NULL;
- ofs->indexdir = ovl_workdir_create(ofs, OVL_INDEXDIR_NAME, true);
- if (ofs->indexdir) {
- ofs->workdir = dget(ofs->indexdir);
+ indexdir = ovl_workdir_create(ofs, OVL_INDEXDIR_NAME, true);
+ if (IS_ERR(indexdir)) {
+ err = PTR_ERR(indexdir);
+ } else if (indexdir) {
+ ofs->indexdir = indexdir;
+ ofs->workdir = dget(indexdir);
err = ovl_setup_trap(sb, ofs->indexdir, &ofs->indexdir_trap,
"indexdir");
@@ -1383,13 +1462,15 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs,
* "trusted.overlay.upper" to indicate that index may have
* directory entries.
*/
- if (ovl_check_origin_xattr(ofs->indexdir)) {
- err = ovl_verify_set_fh(ofs->indexdir, OVL_XATTR_ORIGIN,
+ if (ovl_check_origin_xattr(ofs, ofs->indexdir)) {
+ err = ovl_verify_set_fh(ofs, ofs->indexdir,
+ OVL_XATTR_ORIGIN,
upperpath->dentry, true, false);
if (err)
pr_err("failed to verify index dir 'origin' xattr\n");
}
- err = ovl_verify_upper(ofs->indexdir, upperpath->dentry, true);
+ err = ovl_verify_upper(ofs, ofs->indexdir, upperpath->dentry,
+ true);
if (err)
pr_err("failed to verify index dir 'upper' xattr\n");
@@ -1755,7 +1836,7 @@ static struct dentry *ovl_get_root(struct super_block *sb,
ino = d_inode(upperdentry)->i_ino;
fsid = 0;
ovl_dentry_set_upper_alias(root);
- if (ovl_is_impuredir(upperdentry))
+ if (ovl_is_impuredir(sb, upperdentry))
ovl_set_flag(OVL_IMPURE, d_inode(root));
}
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-21 10:49:43 +0100