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path: root/fs/overlayfs/dir.c
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Diffstat (limited to 'fs/overlayfs/dir.c')
-rw-r--r--fs/overlayfs/dir.c284
1 files changed, 188 insertions, 96 deletions
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 5c9d2d80f..1560fdc09 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -12,6 +12,8 @@
#include <linux/xattr.h>
#include <linux/security.h>
#include <linux/cred.h>
+#include <linux/posix_acl.h>
+#include <linux/posix_acl_xattr.h>
#include "overlayfs.h"
void ovl_cleanup(struct inode *wdir, struct dentry *wdentry)
@@ -138,9 +140,12 @@ static int ovl_dir_getattr(struct vfsmount *mnt, struct dentry *dentry,
int err;
enum ovl_path_type type;
struct path realpath;
+ const struct cred *old_cred;
type = ovl_path_real(dentry, &realpath);
+ old_cred = ovl_override_creds(dentry->d_sb);
err = vfs_getattr(&realpath, stat);
+ revert_creds(old_cred);
if (err)
return err;
@@ -158,6 +163,22 @@ static int ovl_dir_getattr(struct vfsmount *mnt, struct dentry *dentry,
return 0;
}
+/* Common operations required to be done after creation of file on upper */
+static void ovl_instantiate(struct dentry *dentry, struct inode *inode,
+ struct dentry *newdentry, bool hardlink)
+{
+ ovl_dentry_version_inc(dentry->d_parent);
+ ovl_dentry_update(dentry, newdentry);
+ if (!hardlink) {
+ ovl_inode_update(inode, d_inode(newdentry));
+ ovl_copyattr(newdentry->d_inode, inode);
+ } else {
+ WARN_ON(ovl_inode_real(inode, NULL) != d_inode(newdentry));
+ inc_nlink(inode);
+ }
+ d_instantiate(dentry, inode);
+}
+
static int ovl_create_upper(struct dentry *dentry, struct inode *inode,
struct kstat *stat, const char *link,
struct dentry *hardlink)
@@ -167,6 +188,9 @@ static int ovl_create_upper(struct dentry *dentry, struct inode *inode,
struct dentry *newdentry;
int err;
+ if (!hardlink && !IS_POSIXACL(udir))
+ stat->mode &= ~current_umask();
+
inode_lock_nested(udir, I_MUTEX_PARENT);
newdentry = lookup_one_len(dentry->d_name.name, upperdir,
dentry->d_name.len);
@@ -177,10 +201,7 @@ static int ovl_create_upper(struct dentry *dentry, struct inode *inode,
if (err)
goto out_dput;
- ovl_dentry_version_inc(dentry->d_parent);
- ovl_dentry_update(dentry, newdentry);
- ovl_copyattr(newdentry->d_inode, inode);
- d_instantiate(dentry, inode);
+ ovl_instantiate(dentry, inode, newdentry, !!hardlink);
newdentry = NULL;
out_dput:
dput(newdentry);
@@ -291,28 +312,60 @@ static struct dentry *ovl_check_empty_and_clear(struct dentry *dentry)
{
int err;
struct dentry *ret = NULL;
+ enum ovl_path_type type = ovl_path_type(dentry);
LIST_HEAD(list);
err = ovl_check_empty_dir(dentry, &list);
- if (err)
+ if (err) {
ret = ERR_PTR(err);
- else {
- /*
- * If no upperdentry then skip clearing whiteouts.
- *
- * Can race with copy-up, since we don't hold the upperdir
- * mutex. Doesn't matter, since copy-up can't create a
- * non-empty directory from an empty one.
- */
- if (ovl_dentry_upper(dentry))
- ret = ovl_clear_empty(dentry, &list);
+ goto out_free;
}
+ /*
+ * When removing an empty opaque directory, then it makes no sense to
+ * replace it with an exact replica of itself.
+ *
+ * If no upperdentry then skip clearing whiteouts.
+ *
+ * Can race with copy-up, since we don't hold the upperdir mutex.
+ * Doesn't matter, since copy-up can't create a non-empty directory
+ * from an empty one.
+ */
+ if (OVL_TYPE_UPPER(type) && OVL_TYPE_MERGE(type))
+ ret = ovl_clear_empty(dentry, &list);
+
+out_free:
ovl_cache_free(&list);
return ret;
}
+static int ovl_set_upper_acl(struct dentry *upperdentry, const char *name,
+ const struct posix_acl *acl)
+{
+ void *buffer;
+ size_t size;
+ int err;
+
+ if (!IS_ENABLED(CONFIG_FS_POSIX_ACL) || !acl)
+ return 0;
+
+ size = posix_acl_to_xattr(NULL, acl, NULL, 0);
+ buffer = kmalloc(size, GFP_KERNEL);
+ if (!buffer)
+ return -ENOMEM;
+
+ size = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
+ err = size;
+ if (err < 0)
+ goto out_free;
+
+ err = vfs_setxattr(upperdentry, name, buffer, size, XATTR_CREATE);
+out_free:
+ kfree(buffer);
+ return err;
+}
+
static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode,
struct kstat *stat, const char *link,
struct dentry *hardlink)
@@ -324,10 +377,18 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode,
struct dentry *upper;
struct dentry *newdentry;
int err;
+ struct posix_acl *acl, *default_acl;
if (WARN_ON(!workdir))
return -EROFS;
+ if (!hardlink) {
+ err = posix_acl_create(dentry->d_parent->d_inode,
+ &stat->mode, &default_acl, &acl);
+ if (err)
+ return err;
+ }
+
err = ovl_lock_rename_workdir(workdir, upperdir);
if (err)
goto out;
@@ -347,7 +408,34 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode,
if (err)
goto out_dput2;
- if (S_ISDIR(stat->mode)) {
+ /*
+ * mode could have been mutilated due to umask (e.g. sgid directory)
+ */
+ if (!hardlink &&
+ !S_ISLNK(stat->mode) && newdentry->d_inode->i_mode != stat->mode) {
+ struct iattr attr = {
+ .ia_valid = ATTR_MODE,
+ .ia_mode = stat->mode,
+ };
+ inode_lock(newdentry->d_inode);
+ err = notify_change(newdentry, &attr, NULL);
+ inode_unlock(newdentry->d_inode);
+ if (err)
+ goto out_cleanup;
+ }
+ if (!hardlink) {
+ err = ovl_set_upper_acl(newdentry, XATTR_NAME_POSIX_ACL_ACCESS,
+ acl);
+ if (err)
+ goto out_cleanup;
+
+ err = ovl_set_upper_acl(newdentry, XATTR_NAME_POSIX_ACL_DEFAULT,
+ default_acl);
+ if (err)
+ goto out_cleanup;
+ }
+
+ if (!hardlink && S_ISDIR(stat->mode)) {
err = ovl_set_opaque(newdentry);
if (err)
goto out_cleanup;
@@ -363,10 +451,7 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode,
if (err)
goto out_cleanup;
}
- ovl_dentry_version_inc(dentry->d_parent);
- ovl_dentry_update(dentry, newdentry);
- ovl_copyattr(newdentry->d_inode, inode);
- d_instantiate(dentry, inode);
+ ovl_instantiate(dentry, inode, newdentry, !!hardlink);
newdentry = NULL;
out_dput2:
dput(upper);
@@ -375,6 +460,10 @@ out_dput:
out_unlock:
unlock_rename(workdir, upperdir);
out:
+ if (!hardlink) {
+ posix_acl_release(acl);
+ posix_acl_release(default_acl);
+ }
return err;
out_cleanup:
@@ -382,52 +471,42 @@ out_cleanup:
goto out_dput2;
}
-static int ovl_create_or_link(struct dentry *dentry, int mode, dev_t rdev,
- const char *link, struct dentry *hardlink)
+static int ovl_create_or_link(struct dentry *dentry, struct inode *inode,
+ struct kstat *stat, const char *link,
+ struct dentry *hardlink)
{
int err;
- struct inode *inode;
- struct kstat stat = {
- .mode = mode,
- .rdev = rdev,
- };
-
- err = -ENOMEM;
- inode = ovl_new_inode(dentry->d_sb, mode, dentry->d_fsdata);
- if (!inode)
- goto out;
+ const struct cred *old_cred;
+ struct cred *override_cred;
err = ovl_copy_up(dentry->d_parent);
if (err)
- goto out_iput;
-
- if (!ovl_dentry_is_opaque(dentry)) {
- err = ovl_create_upper(dentry, inode, &stat, link, hardlink);
- } else {
- const struct cred *old_cred;
- struct cred *override_cred;
-
- old_cred = ovl_override_creds(dentry->d_sb);
-
- err = -ENOMEM;
- override_cred = prepare_creds();
- if (override_cred) {
- override_cred->fsuid = old_cred->fsuid;
- override_cred->fsgid = old_cred->fsgid;
- put_cred(override_creds(override_cred));
- put_cred(override_cred);
+ return err;
- err = ovl_create_over_whiteout(dentry, inode, &stat,
- link, hardlink);
- }
- revert_creds(old_cred);
+ old_cred = ovl_override_creds(dentry->d_sb);
+ err = -ENOMEM;
+ override_cred = prepare_creds();
+ if (override_cred) {
+ override_cred->fsuid = inode->i_uid;
+ override_cred->fsgid = inode->i_gid;
+ put_cred(override_creds(override_cred));
+ put_cred(override_cred);
+
+ if (!ovl_dentry_is_opaque(dentry))
+ err = ovl_create_upper(dentry, inode, stat, link,
+ hardlink);
+ else
+ err = ovl_create_over_whiteout(dentry, inode, stat,
+ link, hardlink);
}
+ revert_creds(old_cred);
+ if (!err) {
+ struct inode *realinode = d_inode(ovl_dentry_upper(dentry));
- if (!err)
- inode = NULL;
-out_iput:
- iput(inode);
-out:
+ WARN_ON(inode->i_mode != realinode->i_mode);
+ WARN_ON(!uid_eq(inode->i_uid, realinode->i_uid));
+ WARN_ON(!gid_eq(inode->i_gid, realinode->i_gid));
+ }
return err;
}
@@ -435,13 +514,30 @@ static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev,
const char *link)
{
int err;
+ struct inode *inode;
+ struct kstat stat = {
+ .rdev = rdev,
+ };
err = ovl_want_write(dentry);
- if (!err) {
- err = ovl_create_or_link(dentry, mode, rdev, link, NULL);
- ovl_drop_write(dentry);
- }
+ if (err)
+ goto out;
+
+ err = -ENOMEM;
+ inode = ovl_new_inode(dentry->d_sb, mode);
+ if (!inode)
+ goto out_drop_write;
+
+ inode_init_owner(inode, dentry->d_parent->d_inode, mode);
+ stat.mode = inode->i_mode;
+
+ err = ovl_create_or_link(dentry, inode, &stat, link, NULL);
+ if (err)
+ iput(inode);
+out_drop_write:
+ ovl_drop_write(dentry);
+out:
return err;
}
@@ -476,7 +572,7 @@ static int ovl_link(struct dentry *old, struct inode *newdir,
struct dentry *new)
{
int err;
- struct dentry *upper;
+ struct inode *inode;
err = ovl_want_write(old);
if (err)
@@ -486,8 +582,12 @@ static int ovl_link(struct dentry *old, struct inode *newdir,
if (err)
goto out_drop_write;
- upper = ovl_dentry_upper(old);
- err = ovl_create_or_link(new, upper->d_inode->i_mode, 0, NULL, upper);
+ inode = d_inode(old);
+ ihold(inode);
+
+ err = ovl_create_or_link(new, inode, NULL, NULL, ovl_dentry_upper(old));
+ if (err)
+ iput(inode);
out_drop_write:
ovl_drop_write(old);
@@ -511,24 +611,10 @@ static int ovl_remove_and_whiteout(struct dentry *dentry, bool is_dir)
return -EROFS;
if (is_dir) {
- if (OVL_TYPE_MERGE_OR_LOWER(ovl_path_type(dentry))) {
- opaquedir = ovl_check_empty_and_clear(dentry);
- err = PTR_ERR(opaquedir);
- if (IS_ERR(opaquedir))
- goto out;
- } else {
- LIST_HEAD(list);
-
- /*
- * When removing an empty opaque directory, then it
- * makes no sense to replace it with an exact replica of
- * itself. But emptiness still needs to be checked.
- */
- err = ovl_check_empty_dir(dentry, &list);
- ovl_cache_free(&list);
- if (err)
- goto out;
- }
+ opaquedir = ovl_check_empty_and_clear(dentry);
+ err = PTR_ERR(opaquedir);
+ if (IS_ERR(opaquedir))
+ goto out;
}
err = ovl_lock_rename_workdir(workdir, upperdir);
@@ -633,6 +719,8 @@ static int ovl_do_remove(struct dentry *dentry, bool is_dir)
{
enum ovl_path_type type;
int err;
+ const struct cred *old_cred;
+
err = ovl_check_sticky(dentry);
if (err)
@@ -647,14 +735,18 @@ static int ovl_do_remove(struct dentry *dentry, bool is_dir)
goto out_drop_write;
type = ovl_path_type(dentry);
- if (OVL_TYPE_PURE_UPPER(type)) {
- err = ovl_remove_upper(dentry, is_dir);
- } else {
- const struct cred *old_cred = ovl_override_creds(dentry->d_sb);
+ old_cred = ovl_override_creds(dentry->d_sb);
+ if (OVL_TYPE_PURE_UPPER(type))
+ err = ovl_remove_upper(dentry, is_dir);
+ else
err = ovl_remove_and_whiteout(dentry, is_dir);
-
- revert_creds(old_cred);
+ revert_creds(old_cred);
+ if (!err) {
+ if (is_dir)
+ clear_nlink(dentry->d_inode);
+ else
+ drop_nlink(dentry->d_inode);
}
out_drop_write:
ovl_drop_write(dentry);
@@ -760,8 +852,7 @@ static int ovl_rename2(struct inode *olddir, struct dentry *old,
old_opaque = !OVL_TYPE_PURE_UPPER(old_type);
new_opaque = !OVL_TYPE_PURE_UPPER(new_type);
- if (old_opaque || new_opaque)
- old_cred = ovl_override_creds(old->d_sb);
+ old_cred = ovl_override_creds(old->d_sb);
if (overwrite && OVL_TYPE_MERGE_OR_LOWER(new_type) && new_is_dir) {
opaquedir = ovl_check_empty_and_clear(new);
@@ -891,8 +982,7 @@ out_dput_old:
out_unlock:
unlock_rename(new_upperdir, old_upperdir);
out_revert_creds:
- if (old_opaque || new_opaque)
- revert_creds(old_cred);
+ revert_creds(old_cred);
out_drop_write:
ovl_drop_write(old);
out:
@@ -913,8 +1003,10 @@ const struct inode_operations ovl_dir_inode_operations = {
.mknod = ovl_mknod,
.permission = ovl_permission,
.getattr = ovl_dir_getattr,
- .setxattr = ovl_setxattr,
- .getxattr = ovl_getxattr,
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
.listxattr = ovl_listxattr,
- .removexattr = ovl_removexattr,
+ .removexattr = generic_removexattr,
+ .get_acl = ovl_get_acl,
+ .update_time = ovl_update_time,
};