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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 7bb0a47cb615..a29a8afe9b26 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -15,6 +15,7 @@
#include <linux/seq_file.h>
#include <linux/posix_acl_xattr.h>
#include <linux/exportfs.h>
+#include <linux/file.h>
#include "overlayfs.h"
MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
@@ -174,7 +175,7 @@ static struct kmem_cache *ovl_inode_cachep;
static struct inode *ovl_alloc_inode(struct super_block *sb)
{
- struct ovl_inode *oi = kmem_cache_alloc(ovl_inode_cachep, GFP_KERNEL);
+ struct ovl_inode *oi = alloc_inode_sb(sb, ovl_inode_cachep, GFP_KERNEL);
if (!oi)
return NULL;
@@ -184,7 +185,8 @@ static struct inode *ovl_alloc_inode(struct super_block *sb)
oi->version = 0;
oi->flags = 0;
oi->__upperdentry = NULL;
- oi->lower = NULL;
+ oi->lowerpath.dentry = NULL;
+ oi->lowerpath.layer = NULL;
oi->lowerdata = NULL;
mutex_init(&oi->lock);
@@ -205,7 +207,7 @@ static void ovl_destroy_inode(struct inode *inode)
struct ovl_inode *oi = OVL_I(inode);
dput(oi->__upperdentry);
- iput(oi->lower);
+ dput(oi->lowerpath.dentry);
if (S_ISDIR(inode->i_mode))
ovl_dir_cache_free(inode);
else
@@ -300,7 +302,7 @@ static int ovl_sync_fs(struct super_block *sb, int wait)
/**
* ovl_statfs
- * @sb: The overlayfs super block
+ * @dentry: The dentry to query
* @buf: The struct kstatfs to fill in with stats
*
* Get the filesystem statistics. As writes always target the upper layer
@@ -348,6 +350,8 @@ static inline int ovl_xino_def(void)
/**
* ovl_show_options
+ * @m: the seq_file handle
+ * @dentry: The dentry to query
*
* Prints the mount options for a given superblock.
* Returns zero; does not fail.
@@ -761,7 +765,7 @@ static struct dentry *ovl_workdir_create(struct ovl_fs *ofs,
inode_lock_nested(dir, I_MUTEX_PARENT);
retry:
- work = lookup_one_len(name, ofs->workbasedir, strlen(name));
+ work = ovl_lookup_upper(ofs, name, ofs->workbasedir, strlen(name));
if (!IS_ERR(work)) {
struct iattr attr = {
@@ -778,7 +782,7 @@ retry:
goto out_unlock;
retried = true;
- err = ovl_workdir_cleanup(dir, mnt, work, 0);
+ err = ovl_workdir_cleanup(ofs, dir, mnt, work, 0);
dput(work);
if (err == -EINVAL) {
work = ERR_PTR(err);
@@ -787,7 +791,7 @@ retry:
goto retry;
}
- err = ovl_mkdir_real(dir, &work, attr.ia_mode);
+ err = ovl_mkdir_real(ofs, dir, &work, attr.ia_mode);
if (err)
goto out_dput;
@@ -809,19 +813,19 @@ retry:
* allowed as upper are limited to "normal" ones, where checking
* for the above two errors is sufficient.
*/
- err = vfs_removexattr(&init_user_ns, work,
- XATTR_NAME_POSIX_ACL_DEFAULT);
+ err = ovl_do_removexattr(ofs, work,
+ XATTR_NAME_POSIX_ACL_DEFAULT);
if (err && err != -ENODATA && err != -EOPNOTSUPP)
goto out_dput;
- err = vfs_removexattr(&init_user_ns, work,
- XATTR_NAME_POSIX_ACL_ACCESS);
+ err = ovl_do_removexattr(ofs, work,
+ XATTR_NAME_POSIX_ACL_ACCESS);
if (err && err != -ENODATA && err != -EOPNOTSUPP)
goto out_dput;
/* Clear any inherited mode bits */
inode_lock(work->d_inode);
- err = notify_change(&init_user_ns, work, &attr, NULL);
+ err = ovl_do_notify_change(ofs, work, &attr);
inode_unlock(work->d_inode);
if (err)
goto out_dput;
@@ -873,10 +877,6 @@ static int ovl_mount_dir_noesc(const char *name, struct path *path)
pr_err("filesystem on '%s' not supported\n", name);
goto out_put;
}
- if (is_idmapped_mnt(path->mnt)) {
- pr_err("idmapped layers are currently not supported\n");
- goto out_put;
- }
if (!d_is_dir(path->dentry)) {
pr_err("'%s' not a directory\n", name);
goto out_put;
@@ -909,7 +909,7 @@ static int ovl_mount_dir(const char *name, struct path *path)
return err;
}
-static int ovl_check_namelen(struct path *path, struct ovl_fs *ofs,
+static int ovl_check_namelen(const struct path *path, struct ovl_fs *ofs,
const char *name)
{
struct kstatfs statfs;
@@ -1023,7 +1023,20 @@ ovl_posix_acl_xattr_set(const struct xattr_handler *handler,
/* Check that everything is OK before copy-up */
if (value) {
- acl = posix_acl_from_xattr(&init_user_ns, value, size);
+ /* The above comment can be understood in two ways:
+ *
+ * 1. We just want to check whether the basic POSIX ACL format
+ * is ok. For example, if the header is correct and the size
+ * is sane.
+ * 2. We want to know whether the ACL_{GROUP,USER} entries can
+ * be mapped according to the underlying filesystem.
+ *
+ * Currently, we only check 1. If we wanted to check 2. we
+ * would need to pass the mnt_userns and the fs_userns of the
+ * underlying filesystem. But frankly, I think checking 1. is
+ * enough to start the copy-up.
+ */
+ acl = vfs_set_acl_prepare(&init_user_ns, &init_user_ns, value, size);
if (IS_ERR(acl))
return PTR_ERR(acl);
}
@@ -1256,8 +1269,9 @@ out:
* Returns 1 if RENAME_WHITEOUT is supported, 0 if not supported and
* negative values if error is encountered.
*/
-static int ovl_check_rename_whiteout(struct dentry *workdir)
+static int ovl_check_rename_whiteout(struct ovl_fs *ofs)
{
+ struct dentry *workdir = ofs->workdir;
struct inode *dir = d_inode(workdir);
struct dentry *temp;
struct dentry *dest;
@@ -1267,12 +1281,12 @@ static int ovl_check_rename_whiteout(struct dentry *workdir)
inode_lock_nested(dir, I_MUTEX_PARENT);
- temp = ovl_create_temp(workdir, OVL_CATTR(S_IFREG | 0));
+ temp = ovl_create_temp(ofs, workdir, OVL_CATTR(S_IFREG | 0));
err = PTR_ERR(temp);
if (IS_ERR(temp))
goto out_unlock;
- dest = ovl_lookup_temp(workdir);
+ dest = ovl_lookup_temp(ofs, workdir);
err = PTR_ERR(dest);
if (IS_ERR(dest)) {
dput(temp);
@@ -1281,14 +1295,14 @@ static int ovl_check_rename_whiteout(struct dentry *workdir)
/* Name is inline and stable - using snapshot as a copy helper */
take_dentry_name_snapshot(&name, temp);
- err = ovl_do_rename(dir, temp, dir, dest, RENAME_WHITEOUT);
+ err = ovl_do_rename(ofs, dir, temp, dir, dest, RENAME_WHITEOUT);
if (err) {
if (err == -EINVAL)
err = 0;
goto cleanup_temp;
}
- whiteout = lookup_one_len(name.name.name, workdir, name.name.len);
+ whiteout = ovl_lookup_upper(ofs, name.name.name, workdir, name.name.len);
err = PTR_ERR(whiteout);
if (IS_ERR(whiteout))
goto cleanup_temp;
@@ -1297,11 +1311,11 @@ static int ovl_check_rename_whiteout(struct dentry *workdir)
/* Best effort cleanup of whiteout and temp file */
if (err)
- ovl_cleanup(dir, whiteout);
+ ovl_cleanup(ofs, dir, whiteout);
dput(whiteout);
cleanup_temp:
- ovl_cleanup(dir, temp);
+ ovl_cleanup(ofs, dir, temp);
release_dentry_name_snapshot(&name);
dput(temp);
dput(dest);
@@ -1312,16 +1326,17 @@ out_unlock:
return err;
}
-static struct dentry *ovl_lookup_or_create(struct dentry *parent,
+static struct dentry *ovl_lookup_or_create(struct ovl_fs *ofs,
+ 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);
+ child = ovl_lookup_upper(ofs, name, parent, len);
if (!IS_ERR(child) && !child->d_inode)
- child = ovl_create_real(parent->d_inode, child,
+ child = ovl_create_real(ofs, parent->d_inode, child,
OVL_CATTR(mode));
inode_unlock(parent->d_inode);
dput(parent);
@@ -1343,7 +1358,7 @@ static int ovl_create_volatile_dirty(struct ovl_fs *ofs)
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);
+ d = ovl_lookup_or_create(ofs, d, *name, ctr > 1 ? S_IFDIR : S_IFREG);
if (IS_ERR(d))
return PTR_ERR(d);
}
@@ -1352,10 +1367,11 @@ static int ovl_create_volatile_dirty(struct ovl_fs *ofs)
}
static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
- struct path *workpath)
+ const struct path *workpath)
{
struct vfsmount *mnt = ovl_upper_mnt(ofs);
- struct dentry *temp, *workdir;
+ struct dentry *workdir;
+ struct file *tmpfile;
bool rename_whiteout;
bool d_type;
int fh_type;
@@ -1391,16 +1407,16 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
pr_warn("upper fs needs to support d_type.\n");
/* Check if upper/work fs supports O_TMPFILE */
- temp = ovl_do_tmpfile(ofs->workdir, S_IFREG | 0);
- ofs->tmpfile = !IS_ERR(temp);
+ tmpfile = ovl_do_tmpfile(ofs, ofs->workdir, S_IFREG | 0);
+ ofs->tmpfile = !IS_ERR(tmpfile);
if (ofs->tmpfile)
- dput(temp);
+ fput(tmpfile);
else
pr_warn("upper fs does not support tmpfile.\n");
/* Check if upper/work fs supports RENAME_WHITEOUT */
- err = ovl_check_rename_whiteout(ofs->workdir);
+ err = ovl_check_rename_whiteout(ofs);
if (err < 0)
goto out;
@@ -1411,13 +1427,14 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
/*
* Check if upper/work fs supports (trusted|user).overlay.* xattr
*/
- err = ovl_do_setxattr(ofs, ofs->workdir, OVL_XATTR_OPAQUE, "0", 1);
+ err = ovl_setxattr(ofs, ofs->workdir, OVL_XATTR_OPAQUE, "0", 1);
if (err) {
+ pr_warn("failed to set xattr on upper\n");
ofs->noxattr = true;
if (ofs->config.index || ofs->config.metacopy) {
ofs->config.index = false;
ofs->config.metacopy = false;
- pr_warn("upper fs does not support xattr, falling back to index=off,metacopy=off.\n");
+ pr_warn("...falling back to index=off,metacopy=off.\n");
}
/*
* xattr support is required for persistent st_ino.
@@ -1425,11 +1442,13 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
*/
if (ofs->config.xino == OVL_XINO_AUTO) {
ofs->config.xino = OVL_XINO_OFF;
- pr_warn("upper fs does not support xattr, falling back to xino=off.\n");
+ pr_warn("...falling back to xino=off.\n");
}
+ if (err == -EPERM && !ofs->config.userxattr)
+ pr_info("try mounting with 'userxattr' option\n");
err = 0;
} else {
- ovl_do_removexattr(ofs, ofs->workdir, OVL_XATTR_OPAQUE);
+ ovl_removexattr(ofs, ofs->workdir, OVL_XATTR_OPAQUE);
}
/*
@@ -1478,7 +1497,7 @@ out:
}
static int ovl_get_workdir(struct super_block *sb, struct ovl_fs *ofs,
- struct path *upperpath)
+ const struct path *upperpath)
{
int err;
struct path workpath = { };
@@ -1521,7 +1540,7 @@ out:
}
static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs,
- struct ovl_entry *oe, struct path *upperpath)
+ struct ovl_entry *oe, const struct path *upperpath)
{
struct vfsmount *mnt = ovl_upper_mnt(ofs);
struct dentry *indexdir;
@@ -2033,7 +2052,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
sb->s_stack_depth = 0;
sb->s_maxbytes = MAX_LFS_FILESIZE;
atomic_long_set(&ofs->last_ino, 1);
- /* Assume underlaying fs uses 32bit inodes unless proven otherwise */
+ /* Assume underlying fs uses 32bit inodes unless proven otherwise */
if (ofs->config.xino != OVL_XINO_OFF) {
ofs->xino_mode = BITS_PER_LONG - 32;
if (!ofs->xino_mode) {
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.