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path: root/fs/overlayfs/super.c
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Diffstat (limited to 'fs/overlayfs/super.c')
-rw-r--r--fs/overlayfs/super.c103
1 files changed, 61 insertions, 42 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 704b37311467..2e0fc93c2c06 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -64,6 +64,11 @@ static void ovl_entry_stack_free(struct ovl_entry *oe)
dput(oe->lowerstack[i].dentry);
}
+static bool ovl_metacopy_def = IS_ENABLED(CONFIG_OVERLAY_FS_METACOPY);
+module_param_named(metacopy, ovl_metacopy_def, bool, 0644);
+MODULE_PARM_DESC(ovl_metacopy_def,
+ "Default to on or off for the metadata only copy up feature");
+
static void ovl_dentry_release(struct dentry *dentry)
{
struct ovl_entry *oe = dentry->d_fsdata;
@@ -74,31 +79,14 @@ static void ovl_dentry_release(struct dentry *dentry)
}
}
-static int ovl_check_append_only(struct inode *inode, int flag)
-{
- /*
- * This test was moot in vfs may_open() because overlay inode does
- * not have the S_APPEND flag, so re-check on real upper inode
- */
- if (IS_APPEND(inode)) {
- if ((flag & O_ACCMODE) != O_RDONLY && !(flag & O_APPEND))
- return -EPERM;
- if (flag & O_TRUNC)
- return -EPERM;
- }
-
- return 0;
-}
-
static struct dentry *ovl_d_real(struct dentry *dentry,
- const struct inode *inode,
- unsigned int open_flags, unsigned int flags)
+ const struct inode *inode)
{
struct dentry *real;
- int err;
- if (flags & D_REAL_UPPER)
- return ovl_dentry_upper(dentry);
+ /* It's an overlay file */
+ if (inode && d_inode(dentry) == inode)
+ return dentry;
if (!d_is_reg(dentry)) {
if (!inode || inode == d_inode(dentry))
@@ -106,28 +94,19 @@ static struct dentry *ovl_d_real(struct dentry *dentry,
goto bug;
}
- if (open_flags) {
- err = ovl_open_maybe_copy_up(dentry, open_flags);
- if (err)
- return ERR_PTR(err);
- }
-
real = ovl_dentry_upper(dentry);
- if (real && (!inode || inode == d_inode(real))) {
- if (!inode) {
- err = ovl_check_append_only(d_inode(real), open_flags);
- if (err)
- return ERR_PTR(err);
- }
+ if (real && (inode == d_inode(real)))
+ return real;
+
+ if (real && !inode && ovl_has_upperdata(d_inode(dentry)))
return real;
- }
- real = ovl_dentry_lower(dentry);
+ real = ovl_dentry_lowerdata(dentry);
if (!real)
goto bug;
/* Handle recursion */
- real = d_real(real, inode, open_flags, 0);
+ real = d_real(real, inode);
if (!inode || inode == d_inode(real))
return real;
@@ -205,6 +184,7 @@ static struct inode *ovl_alloc_inode(struct super_block *sb)
oi->flags = 0;
oi->__upperdentry = NULL;
oi->lower = NULL;
+ oi->lowerdata = NULL;
mutex_init(&oi->lock);
return &oi->vfs_inode;
@@ -223,8 +203,11 @@ static void ovl_destroy_inode(struct inode *inode)
dput(oi->__upperdentry);
iput(oi->lower);
+ if (S_ISDIR(inode->i_mode))
+ ovl_dir_cache_free(inode);
+ else
+ iput(oi->lowerdata);
kfree(oi->redirect);
- ovl_dir_cache_free(inode);
mutex_destroy(&oi->lock);
call_rcu(&inode->i_rcu, ovl_i_callback);
@@ -376,6 +359,9 @@ static int ovl_show_options(struct seq_file *m, struct dentry *dentry)
"on" : "off");
if (ofs->config.xino != ovl_xino_def())
seq_printf(m, ",xino=%s", ovl_xino_str[ofs->config.xino]);
+ if (ofs->config.metacopy != ovl_metacopy_def)
+ seq_printf(m, ",metacopy=%s",
+ ofs->config.metacopy ? "on" : "off");
return 0;
}
@@ -413,6 +399,8 @@ enum {
OPT_XINO_ON,
OPT_XINO_OFF,
OPT_XINO_AUTO,
+ OPT_METACOPY_ON,
+ OPT_METACOPY_OFF,
OPT_ERR,
};
@@ -429,6 +417,8 @@ static const match_table_t ovl_tokens = {
{OPT_XINO_ON, "xino=on"},
{OPT_XINO_OFF, "xino=off"},
{OPT_XINO_AUTO, "xino=auto"},
+ {OPT_METACOPY_ON, "metacopy=on"},
+ {OPT_METACOPY_OFF, "metacopy=off"},
{OPT_ERR, NULL}
};
@@ -481,6 +471,7 @@ static int ovl_parse_redirect_mode(struct ovl_config *config, const char *mode)
static int ovl_parse_opt(char *opt, struct ovl_config *config)
{
char *p;
+ int err;
config->redirect_mode = kstrdup(ovl_redirect_mode_def(), GFP_KERNEL);
if (!config->redirect_mode)
@@ -555,6 +546,14 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config)
config->xino = OVL_XINO_AUTO;
break;
+ case OPT_METACOPY_ON:
+ config->metacopy = true;
+ break;
+
+ case OPT_METACOPY_OFF:
+ config->metacopy = false;
+ break;
+
default:
pr_err("overlayfs: unrecognized mount option \"%s\" or missing value\n", p);
return -EINVAL;
@@ -569,7 +568,20 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config)
config->workdir = NULL;
}
- return ovl_parse_redirect_mode(config, config->redirect_mode);
+ err = ovl_parse_redirect_mode(config, config->redirect_mode);
+ if (err)
+ return err;
+
+ /* metacopy feature with upper requires redirect_dir=on */
+ if (config->upperdir && config->metacopy && !config->redirect_dir) {
+ pr_warn("overlayfs: metadata only copy up requires \"redirect_dir=on\", falling back to metacopy=off.\n");
+ config->metacopy = false;
+ } else if (config->metacopy && !config->redirect_follow) {
+ pr_warn("overlayfs: metadata only copy up requires \"redirect_dir=follow\" on non-upper mount, falling back to metacopy=off.\n");
+ config->metacopy = false;
+ }
+
+ return 0;
}
#define OVL_WORKDIR_NAME "work"
@@ -1042,7 +1054,8 @@ static int ovl_make_workdir(struct ovl_fs *ofs, struct path *workpath)
if (err) {
ofs->noxattr = true;
ofs->config.index = false;
- pr_warn("overlayfs: upper fs does not support xattr, falling back to index=off.\n");
+ ofs->config.metacopy = false;
+ pr_warn("overlayfs: 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);
@@ -1064,7 +1077,6 @@ static int ovl_make_workdir(struct ovl_fs *ofs, struct path *workpath)
pr_warn("overlayfs: NFS export requires \"index=on\", falling back to nfs_export=off.\n");
ofs->config.nfs_export = false;
}
-
out:
mnt_drop_write(mnt);
return err;
@@ -1375,6 +1387,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
ofs->config.index = ovl_index_def;
ofs->config.nfs_export = ovl_nfs_export_def;
ofs->config.xino = ovl_xino_def();
+ ofs->config.metacopy = ovl_metacopy_def;
err = ovl_parse_opt((char *) data, &ofs->config);
if (err)
goto out_err;
@@ -1445,6 +1458,11 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
}
}
+ if (ofs->config.metacopy && ofs->config.nfs_export) {
+ pr_warn("overlayfs: NFS export is not supported with metadata only copy up, falling back to nfs_export=off.\n");
+ ofs->config.nfs_export = false;
+ }
+
if (ofs->config.nfs_export)
sb->s_export_op = &ovl_export_operations;
@@ -1455,7 +1473,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
sb->s_op = &ovl_super_operations;
sb->s_xattr = ovl_xattr_handlers;
sb->s_fs_info = ofs;
- sb->s_flags |= SB_POSIXACL | SB_NOREMOTELOCK;
+ sb->s_flags |= SB_POSIXACL;
err = -ENOMEM;
root_dentry = d_make_root(ovl_new_inode(sb, S_IFDIR, 0));
@@ -1474,8 +1492,9 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
/* Root is always merge -> can have whiteouts */
ovl_set_flag(OVL_WHITEOUTS, d_inode(root_dentry));
ovl_dentry_set_flag(OVL_E_CONNECTED, root_dentry);
+ ovl_set_upperdata(d_inode(root_dentry));
ovl_inode_init(d_inode(root_dentry), upperpath.dentry,
- ovl_dentry_lower(root_dentry));
+ ovl_dentry_lower(root_dentry), NULL);
sb->s_root = root_dentry;
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-23 12:41:11 +0300