The patch titled
Subject: autofs: improve ioctl sbi checks
has been added to the -mm tree. Its filename is
autofs-improve-ioctl-sbi-checks.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/autofs-improve-ioctl-sbi-checks.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/autofs-improve-ioctl-sbi-checks.patch
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------------------------------------------------------
From: Ian Kent <raven@xxxxxxxxxx>
Subject: autofs: improve ioctl sbi checks
Al Viro made some suggestions to improve the implementation of commit
0633da48f0 "fix autofs_sbi() does not check super block type".
The check is unnecessary in all cases except for ioctl usage so placing
the check in the super block accessor function adds a small overhead to
the common case where it isn't needed.
So it's sufficient to do this in the ioctl code only.
Also the check in the ioctl code is needlessly complex.
Link: http://lkml.kernel.org/r/154296970987.9889.1597442413573683096.stgit@pluto-themaw-net
Signed-off-by: Ian Kent <raven@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/fs/autofs/autofs_i.h~autofs-improve-ioctl-sbi-checks
+++ a/fs/autofs/autofs_i.h
@@ -126,8 +126,7 @@ struct autofs_sb_info {
static inline struct autofs_sb_info *autofs_sbi(struct super_block *sb)
{
- return sb->s_magic != AUTOFS_SUPER_MAGIC ?
- NULL : (struct autofs_sb_info *)(sb->s_fs_info);
+ return (struct autofs_sb_info *)(sb->s_fs_info);
}
static inline struct autofs_info *autofs_dentry_ino(struct dentry *dentry)
--- a/fs/autofs/dev-ioctl.c~autofs-improve-ioctl-sbi-checks
+++ a/fs/autofs/dev-ioctl.c
@@ -14,6 +14,8 @@
#include "autofs_i.h"
+extern struct file_system_type autofs_fs_type;
+
/*
* This module implements an interface for routing autofs ioctl control
* commands via a miscellaneous device file.
@@ -151,22 +153,6 @@ out:
return err;
}
-/*
- * Get the autofs super block info struct from the file opened on
- * the autofs mount point.
- */
-static struct autofs_sb_info *autofs_dev_ioctl_sbi(struct file *f)
-{
- struct autofs_sb_info *sbi = NULL;
- struct inode *inode;
-
- if (f) {
- inode = file_inode(f);
- sbi = autofs_sbi(inode->i_sb);
- }
- return sbi;
-}
-
/* Return autofs dev ioctl version */
static int autofs_dev_ioctl_version(struct file *fp,
struct autofs_sb_info *sbi,
@@ -658,6 +644,8 @@ static int _autofs_dev_ioctl(unsigned in
if (cmd != AUTOFS_DEV_IOCTL_VERSION_CMD &&
cmd != AUTOFS_DEV_IOCTL_OPENMOUNT_CMD &&
cmd != AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD) {
+ struct super_block *sb;
+
fp = fget(param->ioctlfd);
if (!fp) {
if (cmd == AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD)
@@ -666,12 +654,13 @@ static int _autofs_dev_ioctl(unsigned in
goto out;
}
- sbi = autofs_dev_ioctl_sbi(fp);
- if (!sbi || sbi->magic != AUTOFS_SBI_MAGIC) {
+ sb = file_inode(fp)->i_sb;
+ if (sb->s_type != &autofs_fs_type) {
err = -EINVAL;
fput(fp);
goto out;
}
+ sbi = autofs_sbi(sb);
/*
* Admin needs to be able to set the mount catatonic in
--- a/fs/autofs/init.c~autofs-improve-ioctl-sbi-checks
+++ a/fs/autofs/init.c
@@ -16,7 +16,7 @@ static struct dentry *autofs_mount(struc
return mount_nodev(fs_type, flags, data, autofs_fill_super);
}
-static struct file_system_type autofs_fs_type = {
+struct file_system_type autofs_fs_type = {
.owner = THIS_MODULE,
.name = "autofs",
.mount = autofs_mount,
_
Patches currently in -mm which might be from raven@xxxxxxxxxx are
autofs-improve-ioctl-sbi-checks.patch
autofs-fix-possible-inode-leak-in-autofs_fill_super.patch
autofs-simplify-parse_options-function-call.patch
autofs-change-catatonic-setting-to-a-bit-flag.patch
autofs-add-strictexpire-mount-option.patch
