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-rw-r--r--fs/overlayfs/Kconfig1
-rw-r--r--fs/overlayfs/Makefile1
-rw-r--r--fs/overlayfs/copy_up.c6
-rw-r--r--fs/overlayfs/dir.c2
-rw-r--r--fs/overlayfs/export.c2
-rw-r--r--fs/overlayfs/file.c133
-rw-r--r--fs/overlayfs/inode.c3
-rw-r--r--fs/overlayfs/overlayfs.h2
-rw-r--r--fs/overlayfs/super.c13
9 files changed, 122 insertions, 41 deletions
diff --git a/fs/overlayfs/Kconfig b/fs/overlayfs/Kconfig
index 2ef91be2a04e..444e2da4f60e 100644
--- a/fs/overlayfs/Kconfig
+++ b/fs/overlayfs/Kconfig
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
config OVERLAY_FS
tristate "Overlay filesystem support"
select EXPORTFS
diff --git a/fs/overlayfs/Makefile b/fs/overlayfs/Makefile
index 46e1ff8ac056..9164c585eb2f 100644
--- a/fs/overlayfs/Makefile
+++ b/fs/overlayfs/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
#
# Makefile for the overlay filesystem.
#
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 68b3303e4b46..56feaa739979 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -909,14 +909,14 @@ static bool ovl_open_need_copy_up(struct dentry *dentry, int flags)
return true;
}
-int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags)
+int ovl_maybe_copy_up(struct dentry *dentry, int flags)
{
int err = 0;
- if (ovl_open_need_copy_up(dentry, file_flags)) {
+ if (ovl_open_need_copy_up(dentry, flags)) {
err = ovl_want_write(dentry);
if (!err) {
- err = ovl_copy_up_flags(dentry, file_flags);
+ err = ovl_copy_up_flags(dentry, flags);
ovl_drop_write(dentry);
}
}
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 82c129bfe58d..93872bb50230 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -260,7 +260,7 @@ static int ovl_instantiate(struct dentry *dentry, struct inode *inode,
* hashed directory inode aliases.
*/
inode = ovl_get_inode(dentry->d_sb, &oip);
- if (WARN_ON(IS_ERR(inode)))
+ if (IS_ERR(inode))
return PTR_ERR(inode);
} else {
WARN_ON(ovl_inode_real(inode) != d_inode(newdentry));
diff --git a/fs/overlayfs/export.c b/fs/overlayfs/export.c
index 54e5d17d7f3e..cc1c9e5606ba 100644
--- a/fs/overlayfs/export.c
+++ b/fs/overlayfs/export.c
@@ -398,7 +398,7 @@ static struct dentry *ovl_lookup_real_one(struct dentry *connected,
* pointer because we hold no lock on the real dentry.
*/
take_dentry_name_snapshot(&name, real);
- this = lookup_one_len(name.name, connected, strlen(name.name));
+ this = lookup_one_len(name.name.name, connected, name.name.len);
err = PTR_ERR(this);
if (IS_ERR(this)) {
goto fail;
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index 84dd957efa24..540a8b845145 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -11,6 +11,7 @@
#include <linux/mount.h>
#include <linux/xattr.h>
#include <linux/uio.h>
+#include <linux/uaccess.h>
#include "overlayfs.h"
static char ovl_whatisit(struct inode *inode, struct inode *realinode)
@@ -29,10 +30,11 @@ static struct file *ovl_open_realfile(const struct file *file,
struct inode *inode = file_inode(file);
struct file *realfile;
const struct cred *old_cred;
+ int flags = file->f_flags | O_NOATIME | FMODE_NONOTIFY;
old_cred = ovl_override_creds(inode->i_sb);
- realfile = open_with_fake_path(&file->f_path, file->f_flags | O_NOATIME,
- realinode, current_cred());
+ realfile = open_with_fake_path(&file->f_path, flags, realinode,
+ current_cred());
revert_creds(old_cred);
pr_debug("open(%p[%pD2/%c], 0%o) -> (%p, 0%o)\n",
@@ -50,7 +52,7 @@ static int ovl_change_flags(struct file *file, unsigned int flags)
int err;
/* No atime modificaton on underlying */
- flags |= O_NOATIME;
+ flags |= O_NOATIME | FMODE_NONOTIFY;
/* If some flag changed that cannot be changed then something's amiss */
if (WARN_ON((file->f_flags ^ flags) & ~OVL_SETFL_MASK))
@@ -116,11 +118,10 @@ static int ovl_real_fdget(const struct file *file, struct fd *real)
static int ovl_open(struct inode *inode, struct file *file)
{
- struct dentry *dentry = file_dentry(file);
struct file *realfile;
int err;
- err = ovl_open_maybe_copy_up(dentry, file->f_flags);
+ err = ovl_maybe_copy_up(file_dentry(file), file->f_flags);
if (err)
return err;
@@ -145,11 +146,47 @@ static int ovl_release(struct inode *inode, struct file *file)
static loff_t ovl_llseek(struct file *file, loff_t offset, int whence)
{
- struct inode *realinode = ovl_inode_real(file_inode(file));
+ struct inode *inode = file_inode(file);
+ struct fd real;
+ const struct cred *old_cred;
+ ssize_t ret;
+
+ /*
+ * The two special cases below do not need to involve real fs,
+ * so we can optimizing concurrent callers.
+ */
+ if (offset == 0) {
+ if (whence == SEEK_CUR)
+ return file->f_pos;
+
+ if (whence == SEEK_SET)
+ return vfs_setpos(file, 0, 0);
+ }
+
+ ret = ovl_real_fdget(file, &real);
+ if (ret)
+ return ret;
+
+ /*
+ * Overlay file f_pos is the master copy that is preserved
+ * through copy up and modified on read/write, but only real
+ * fs knows how to SEEK_HOLE/SEEK_DATA and real fs may impose
+ * limitations that are more strict than ->s_maxbytes for specific
+ * files, so we use the real file to perform seeks.
+ */
+ inode_lock(inode);
+ real.file->f_pos = file->f_pos;
+
+ old_cred = ovl_override_creds(inode->i_sb);
+ ret = vfs_llseek(real.file, offset, whence);
+ revert_creds(old_cred);
+
+ file->f_pos = real.file->f_pos;
+ inode_unlock(inode);
+
+ fdput(real);
- return generic_file_llseek_size(file, offset, whence,
- realinode->i_sb->s_maxbytes,
- i_size_read(realinode));
+ return ret;
}
static void ovl_file_accessed(struct file *file)
@@ -372,10 +409,68 @@ static long ovl_real_ioctl(struct file *file, unsigned int cmd,
return ret;
}
-static long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+static unsigned int ovl_get_inode_flags(struct inode *inode)
+{
+ unsigned int flags = READ_ONCE(inode->i_flags);
+ unsigned int ovl_iflags = 0;
+
+ if (flags & S_SYNC)
+ ovl_iflags |= FS_SYNC_FL;
+ if (flags & S_APPEND)
+ ovl_iflags |= FS_APPEND_FL;
+ if (flags & S_IMMUTABLE)
+ ovl_iflags |= FS_IMMUTABLE_FL;
+ if (flags & S_NOATIME)
+ ovl_iflags |= FS_NOATIME_FL;
+
+ return ovl_iflags;
+}
+
+static long ovl_ioctl_set_flags(struct file *file, unsigned long arg)
{
long ret;
struct inode *inode = file_inode(file);
+ unsigned int flags;
+ unsigned int old_flags;
+
+ if (!inode_owner_or_capable(inode))
+ return -EACCES;
+
+ if (get_user(flags, (int __user *) arg))
+ return -EFAULT;
+
+ ret = mnt_want_write_file(file);
+ if (ret)
+ return ret;
+
+ inode_lock(inode);
+
+ /* Check the capability before cred override */
+ ret = -EPERM;
+ old_flags = ovl_get_inode_flags(inode);
+ if (((flags ^ old_flags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) &&
+ !capable(CAP_LINUX_IMMUTABLE))
+ goto unlock;
+
+ ret = ovl_maybe_copy_up(file_dentry(file), O_WRONLY);
+ if (ret)
+ goto unlock;
+
+ ret = ovl_real_ioctl(file, FS_IOC_SETFLAGS, arg);
+
+ ovl_copyflags(ovl_inode_real(inode), inode);
+unlock:
+ inode_unlock(inode);
+
+ mnt_drop_write_file(file);
+
+ return ret;
+
+}
+
+static long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ long ret;
switch (cmd) {
case FS_IOC_GETFLAGS:
@@ -383,23 +478,7 @@ static long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
break;
case FS_IOC_SETFLAGS:
- if (!inode_owner_or_capable(inode))
- return -EACCES;
-
- ret = mnt_want_write_file(file);
- if (ret)
- return ret;
-
- ret = ovl_copy_up_with_data(file_dentry(file));
- if (!ret) {
- ret = ovl_real_ioctl(file, cmd, arg);
-
- inode_lock(inode);
- ovl_copyflags(ovl_inode_real(inode), inode);
- inode_unlock(inode);
- }
-
- mnt_drop_write_file(file);
+ ret = ovl_ioctl_set_flags(file, arg);
break;
default:
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 3b7ed5d2279c..b48273e846ad 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -832,7 +832,7 @@ struct inode *ovl_get_inode(struct super_block *sb,
int fsid = bylower ? oip->lowerpath->layer->fsid : 0;
bool is_dir, metacopy = false;
unsigned long ino = 0;
- int err = -ENOMEM;
+ int err = oip->newinode ? -EEXIST : -ENOMEM;
if (!realinode)
realinode = d_inode(lowerdentry);
@@ -917,6 +917,7 @@ out:
return inode;
out_err:
+ pr_warn_ratelimited("overlayfs: failed to get inode (%i)\n", err);
inode = ERR_PTR(err);
goto out;
}
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 9c6018287d57..d26efed9f80a 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -421,7 +421,7 @@ extern const struct file_operations ovl_file_operations;
int ovl_copy_up(struct dentry *dentry);
int ovl_copy_up_with_data(struct dentry *dentry);
int ovl_copy_up_flags(struct dentry *dentry, int flags);
-int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags);
+int ovl_maybe_copy_up(struct dentry *dentry, int flags);
int ovl_copy_xattr(struct dentry *old, struct dentry *new);
int ovl_set_attr(struct dentry *upper, struct kstat *stat);
struct ovl_fh *ovl_encode_real_fh(struct dentry *real, bool is_upper);
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 0116735cc321..5ec4fc2f5d7e 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -190,11 +190,13 @@ static struct inode *ovl_alloc_inode(struct super_block *sb)
return &oi->vfs_inode;
}
-static void ovl_i_callback(struct rcu_head *head)
+static void ovl_free_inode(struct inode *inode)
{
- struct inode *inode = container_of(head, struct inode, i_rcu);
+ struct ovl_inode *oi = OVL_I(inode);
- kmem_cache_free(ovl_inode_cachep, OVL_I(inode));
+ kfree(oi->redirect);
+ mutex_destroy(&oi->lock);
+ kmem_cache_free(ovl_inode_cachep, oi);
}
static void ovl_destroy_inode(struct inode *inode)
@@ -207,10 +209,6 @@ static void ovl_destroy_inode(struct inode *inode)
ovl_dir_cache_free(inode);
else
iput(oi->lowerdata);
- kfree(oi->redirect);
- mutex_destroy(&oi->lock);
-
- call_rcu(&inode->i_rcu, ovl_i_callback);
}
static void ovl_free_fs(struct ovl_fs *ofs)
@@ -377,6 +375,7 @@ static int ovl_remount(struct super_block *sb, int *flags, char *data)
static const struct super_operations ovl_super_operations = {
.alloc_inode = ovl_alloc_inode,
+ .free_inode = ovl_free_inode,
.destroy_inode = ovl_destroy_inode,
.drop_inode = generic_delete_inode,
.put_super = ovl_put_super,
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2025-05-06 17:19:52 +0200