From: Miklos Szeredi <mszeredi@redhat.com>
To: linux-unionfs@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [RFC PATCH 27/35] Revert "ovl: don't allow writing ioctl on lower layer"
Date: Thu, 12 Apr 2018 17:08:18 +0200 [thread overview]
Message-ID: <20180412150826.20988-28-mszeredi@redhat.com> (raw)
In-Reply-To: <20180412150826.20988-1-mszeredi@redhat.com>
This reverts commit 7c6893e3c9abf6a9676e060a1e35e5caca673d57.
Overlayfs no longer relies on the vfs for checking writability of files.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
---
fs/internal.h | 2 --
fs/namespace.c | 64 +++-------------------------------------------------------
fs/open.c | 4 ++--
fs/xattr.c | 9 ++++-----
4 files changed, 9 insertions(+), 70 deletions(-)
diff --git a/fs/internal.h b/fs/internal.h
index f0eaa33890d9..d7fdd56bafd3 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -72,10 +72,8 @@ extern void __init mnt_init(void);
extern int __mnt_want_write(struct vfsmount *);
extern int __mnt_want_write_file(struct file *);
-extern int mnt_want_write_file_path(struct file *);
extern void __mnt_drop_write(struct vfsmount *);
extern void __mnt_drop_write_file(struct file *);
-extern void mnt_drop_write_file_path(struct file *);
/*
* fs_struct.c
diff --git a/fs/namespace.c b/fs/namespace.c
index 9ec9bf74116b..e2645ef331f2 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -431,18 +431,13 @@ int __mnt_want_write_file(struct file *file)
}
/**
- * mnt_want_write_file_path - get write access to a file's mount
+ * mnt_want_write_file - get write access to a file's mount
* @file: the file who's mount on which to take a write
*
* This is like mnt_want_write, but it takes a file and can
* do some optimisations if the file is open for write already
- *
- * Called by the vfs for cases when we have an open file at hand, but will do an
- * inode operation on it (important distinction for files opened on overlayfs,
- * since the file operations will come from the real underlying file, while
- * inode operations come from the overlay).
*/
-int mnt_want_write_file_path(struct file *file)
+int mnt_want_write_file(struct file *file)
{
int ret;
@@ -452,53 +447,6 @@ int mnt_want_write_file_path(struct file *file)
sb_end_write(file->f_path.mnt->mnt_sb);
return ret;
}
-
-static inline int may_write_real(struct file *file)
-{
- struct dentry *dentry = file->f_path.dentry;
- struct dentry *upperdentry;
-
- /* Writable file? */
- if (file->f_mode & FMODE_WRITER)
- return 0;
-
- /* Not overlayfs? */
- if (likely(!(dentry->d_flags & DCACHE_OP_REAL)))
- return 0;
-
- /* File refers to upper, writable layer? */
- upperdentry = d_real(dentry, NULL, 0, D_REAL_UPPER);
- if (upperdentry && file_inode(file) == d_inode(upperdentry))
- return 0;
-
- /* Lower layer: can't write to real file, sorry... */
- return -EPERM;
-}
-
-/**
- * mnt_want_write_file - get write access to a file's mount
- * @file: the file who's mount on which to take a write
- *
- * This is like mnt_want_write, but it takes a file and can
- * do some optimisations if the file is open for write already
- *
- * Mostly called by filesystems from their ioctl operation before performing
- * modification. On overlayfs this needs to check if the file is on a read-only
- * lower layer and deny access in that case.
- */
-int mnt_want_write_file(struct file *file)
-{
- int ret;
-
- ret = may_write_real(file);
- if (!ret) {
- sb_start_write(file_inode(file)->i_sb);
- ret = __mnt_want_write_file(file);
- if (ret)
- sb_end_write(file_inode(file)->i_sb);
- }
- return ret;
-}
EXPORT_SYMBOL_GPL(mnt_want_write_file);
/**
@@ -536,15 +484,9 @@ void __mnt_drop_write_file(struct file *file)
__mnt_drop_write(file->f_path.mnt);
}
-void mnt_drop_write_file_path(struct file *file)
-{
- mnt_drop_write(file->f_path.mnt);
-}
-
void mnt_drop_write_file(struct file *file)
{
- __mnt_drop_write(file->f_path.mnt);
- sb_end_write(file_inode(file)->i_sb);
+ mnt_drop_write(file->f_path.mnt);
}
EXPORT_SYMBOL(mnt_drop_write_file);
diff --git a/fs/open.c b/fs/open.c
index 442088ca30f9..00b1f18475ba 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -670,12 +670,12 @@ SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group)
if (!f.file)
goto out;
- error = mnt_want_write_file_path(f.file);
+ error = mnt_want_write_file(f.file);
if (error)
goto out_fput;
audit_file(f.file);
error = chown_common(&f.file->f_path, user, group);
- mnt_drop_write_file_path(f.file);
+ mnt_drop_write_file(f.file);
out_fput:
fdput(f);
out:
diff --git a/fs/xattr.c b/fs/xattr.c
index 61cd28ba25f3..78eaffbdbee0 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -23,7 +23,6 @@
#include <linux/posix_acl_xattr.h>
#include <linux/uaccess.h>
-#include "internal.h"
static const char *
strcmp_prefix(const char *a, const char *a_prefix)
@@ -503,10 +502,10 @@ SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name,
if (!f.file)
return error;
audit_file(f.file);
- error = mnt_want_write_file_path(f.file);
+ error = mnt_want_write_file(f.file);
if (!error) {
error = setxattr(f.file->f_path.dentry, name, value, size, flags);
- mnt_drop_write_file_path(f.file);
+ mnt_drop_write_file(f.file);
}
fdput(f);
return error;
@@ -735,10 +734,10 @@ SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name)
if (!f.file)
return error;
audit_file(f.file);
- error = mnt_want_write_file_path(f.file);
+ error = mnt_want_write_file(f.file);
if (!error) {
error = removexattr(f.file->f_path.dentry, name);
- mnt_drop_write_file_path(f.file);
+ mnt_drop_write_file(f.file);
}
fdput(f);
return error;
--
2.14.3
next prev parent reply other threads:[~2018-04-12 15:09 UTC|newest]
Thread overview: 79+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-12 15:07 [RFC PATCH 00/35] overlayfs: stack file operations Miklos Szeredi
2018-04-12 15:07 ` [RFC PATCH 01/35] vfs: clean up dedup Miklos Szeredi
2018-04-12 16:25 ` Matthew Wilcox
2018-04-12 17:24 ` Miklos Szeredi
2018-04-12 15:07 ` [RFC PATCH 02/35] vfs: add path_open() Miklos Szeredi
2018-04-12 16:38 ` Matthew Wilcox
2018-04-12 15:07 ` [RFC PATCH 03/35] vfs: optionally don't account file in nr_files Miklos Szeredi
2018-04-12 15:07 ` [RFC PATCH 04/35] ovl: copy up times Miklos Szeredi
2018-04-13 8:25 ` Amir Goldstein
2018-04-13 14:23 ` Vivek Goyal
2018-04-12 15:07 ` [RFC PATCH 05/35] ovl: copy up inode flags Miklos Szeredi
2018-04-12 15:07 ` [RFC PATCH 06/35] Revert "Revert "ovl: get_write_access() in truncate"" Miklos Szeredi
2018-04-12 15:07 ` [RFC PATCH 07/35] ovl: copy up file size as well Miklos Szeredi
2018-04-24 18:10 ` Vivek Goyal
2018-04-12 15:07 ` [RFC PATCH 08/35] ovl: deal with overlay files in ovl_d_real() Miklos Szeredi
2018-04-12 15:08 ` [RFC PATCH 09/35] ovl: stack file ops Miklos Szeredi
2018-04-26 14:13 ` Vivek Goyal
2018-04-26 14:43 ` Miklos Szeredi
2018-04-26 14:56 ` Vivek Goyal
2018-04-26 15:01 ` Miklos Szeredi
2018-04-26 15:13 ` Vivek Goyal
2018-04-26 15:21 ` Miklos Szeredi
2018-04-12 15:08 ` [RFC PATCH 10/35] ovl: add helper to return real file Miklos Szeredi
2018-04-12 15:08 ` [RFC PATCH 11/35] ovl: readd read_iter Miklos Szeredi
2018-04-13 13:35 ` Amir Goldstein
2018-04-12 15:08 ` [RFC PATCH 12/35] ovl: readd write_iter Miklos Szeredi
2018-04-12 15:08 ` [RFC PATCH 13/35] ovl: readd fsync Miklos Szeredi
2018-04-23 13:36 ` Vivek Goyal
2018-04-23 13:39 ` Miklos Szeredi
2018-04-23 13:53 ` Vivek Goyal
2018-04-23 14:09 ` Miklos Szeredi
2018-04-12 15:08 ` [RFC PATCH 14/35] ovl: readd mmap Miklos Szeredi
2018-04-12 15:08 ` [RFC PATCH 15/35] ovl: readd fallocate Miklos Szeredi
2018-04-12 15:08 ` [RFC PATCH 16/35] ovl: readd lsattr/chattr support Miklos Szeredi
2018-04-13 14:48 ` Amir Goldstein
2018-04-17 19:51 ` Amir Goldstein
2018-04-22 8:35 ` Amir Goldstein
2018-04-22 15:18 ` Amir Goldstein
2018-04-23 10:21 ` Miklos Szeredi
2018-04-23 10:28 ` Miklos Szeredi
2018-04-23 6:11 ` Ritesh Harjani
2018-04-12 15:08 ` [RFC PATCH 17/35] ovl: readd fiemap Miklos Szeredi
2018-04-12 15:08 ` [RFC PATCH 18/35] ovl: readd O_DIRECT support Miklos Szeredi
2018-04-12 15:08 ` [RFC PATCH 19/35] ovl: readd reflink/copyfile/dedup support Miklos Szeredi
2018-04-17 20:31 ` Amir Goldstein
2018-04-18 8:39 ` Amir Goldstein
2018-05-03 16:04 ` Miklos Szeredi
2018-05-03 19:48 ` Amir Goldstein
2018-04-12 15:08 ` [RFC PATCH 20/35] vfs: don't open real Miklos Szeredi
2018-04-12 15:08 ` [RFC PATCH 21/35] vfs: add f_op->pre_mmap() Miklos Szeredi
2018-04-12 15:08 ` [RFC PATCH 22/35] ovl: copy-up on MAP_SHARED Miklos Szeredi
2018-04-12 15:08 ` [RFC PATCH 23/35] vfs: simplify dentry_open() Miklos Szeredi
2018-04-12 15:08 ` [RFC PATCH 24/35] Revert "ovl: fix relatime for directories" Miklos Szeredi
2018-04-13 14:02 ` Amir Goldstein
2018-04-13 15:55 ` Vivek Goyal
2018-04-12 15:08 ` [RFC PATCH 25/35] Revert "vfs: update ovl inode before relatime check" Miklos Szeredi
2018-04-12 15:08 ` [RFC PATCH 26/35] Revert "ovl: fix may_write_real() for overlayfs directories" Miklos Szeredi
2018-04-12 15:08 ` Miklos Szeredi [this message]
2018-04-12 15:08 ` [RFC PATCH 28/35] Revert "vfs: add flags to d_real()" Miklos Szeredi
2018-04-12 15:08 ` [RFC PATCH 29/35] Revert "vfs: do get_write_access() on upper layer of overlayfs" Miklos Szeredi
2018-04-12 15:08 ` [RFC PATCH 30/35] Revert "vfs: make argument of d_real_inode() const" Miklos Szeredi
2018-04-12 15:08 ` [RFC PATCH 31/35] Revert "vfs: add d_real_inode() helper" Miklos Szeredi
2018-04-18 8:19 ` Amir Goldstein
2018-04-18 11:42 ` Miklos Szeredi
2018-04-18 13:38 ` Steven Rostedt
2018-04-18 13:49 ` Miklos Szeredi
2018-04-18 13:56 ` Steven Rostedt
2018-04-19 19:54 ` Vivek Goyal
2018-04-20 9:14 ` Miklos Szeredi
2018-04-12 15:08 ` [RFC PATCH 32/35] Partially revert "locks: fix file locking on overlayfs" Miklos Szeredi
2018-04-12 15:08 ` [RFC PATCH 33/35] Revert "fsnotify: support overlayfs" Miklos Szeredi
2018-04-12 15:08 ` [RFC PATCH 34/35] vfs: simplify d_op->d_real() Miklos Szeredi
2018-04-12 15:08 ` [RFC PATCH 35/35] ovl: fix documentation of non-standard behavior Miklos Szeredi
2018-04-13 11:23 ` Amir Goldstein
2018-04-25 14:49 ` [RFC PATCH 00/35] overlayfs: stack file operations J. R. Okajima
2018-04-25 19:44 ` Miklos Szeredi
2018-05-04 15:23 ` Miklos Szeredi
2018-05-05 16:37 ` Amir Goldstein
2018-05-08 14:25 ` Miklos Szeredi
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