2009-10-28 18:51:35

by Kay Sievers

Subject: Driver-Core: devtmpfs - do not remove non-kernel-created directories

From: Kay Sievers <[email protected]>
Subject: Driver-Core: devtmpfs - do not remove non-kernel-created directories

Signed-off-by: Kay Sievers <[email protected]>
---
drivers/base/devtmpfs.c | 39 ++++++++++++++++-----------------------
1 file changed, 16 insertions(+), 23 deletions(-)

--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -76,37 +76,26 @@ static int dev_mkdir(const char *name, m
dentry = lookup_create(&nd, 1);
if (!IS_ERR(dentry)) {
err = vfs_mkdir(nd.path.dentry->d_inode, dentry, mode);
+ if (!err)
+ /* mark as kernel-created inode */
+ dentry->d_inode->i_private = &dev_mnt;
dput(dentry);
} else {
err = PTR_ERR(dentry);
}
- mutex_unlock(&nd.path.dentry->d_inode->i_mutex);

+ mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
path_put(&nd.path);
return err;
}

static int create_path(const char *nodepath)
{
- struct nameidata nd;
- int err = 0;
+ int err;

read_lock(&dirlock);
- err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,
- nodepath, LOOKUP_PARENT, &nd);
- if (err == 0) {
- struct dentry *dentry;
-
- /* create directory right away */
- dentry = lookup_create(&nd, 1);
- if (!IS_ERR(dentry)) {
- err = vfs_mkdir(nd.path.dentry->d_inode,
- dentry, 0755);
- dput(dentry);
- }
- mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
- path_put(&nd.path);
- } else if (err == -ENOENT) {
+ err = dev_mkdir(nodepath, 0755);
+ if (err == -ENOENT) {
char *path;
char *s;

@@ -129,7 +118,6 @@ static int create_path(const char *nodep
kfree(path);
}
read_unlock(&dirlock);
-
return err;
}

@@ -211,16 +199,21 @@ static int dev_rmdir(const char *name)
mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len);
if (!IS_ERR(dentry)) {
- if (dentry->d_inode)
- err = vfs_rmdir(nd.path.dentry->d_inode, dentry);
- else
+ if (dentry->d_inode) {
+ if (dentry->d_inode->i_private == &dev_mnt)
+ err = vfs_rmdir(nd.path.dentry->d_inode,
+ dentry);
+ else
+ err = -EPERM;
+ } else {
err = -ENOENT;
+ }
dput(dentry);
} else {
err = PTR_ERR(dentry);
}
- mutex_unlock(&nd.path.dentry->d_inode->i_mutex);

+ mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
path_put(&nd.path);
return err;
}

2009-10-29 19:29:07

by Greg KH

Subject: patch driver-core-devtmpfs-do-not-remove-non-kernel-created-directories.patch added to gregkh-2.6 tree

This is a note to let you know that I've just added the patch titled

Subject: Driver Core: devtmpfs: do not remove non-kernel-created directories

to my gregkh-2.6 tree. Its filename is

driver-core-devtmpfs-do-not-remove-non-kernel-created-directories.patch

This tree can be found at
http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/patches/


>From [email protected] Thu Oct 29 12:00:12 2009
From: Kay Sievers <[email protected]>
Date: Wed, 28 Oct 2009 19:51:26 +0100
Subject: Driver Core: devtmpfs: do not remove non-kernel-created directories
To: Greg KH <[email protected]>
Cc: linux-kernel <[email protected]>
Message-ID: <[email protected]>


From: Kay Sievers <[email protected]>

Signed-off-by: Kay Sievers <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
drivers/base/devtmpfs.c | 39 ++++++++++++++++-----------------------
1 file changed, 16 insertions(+), 23 deletions(-)

--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -76,37 +76,26 @@ static int dev_mkdir(const char *name, m
dentry = lookup_create(&nd, 1);
if (!IS_ERR(dentry)) {
err = vfs_mkdir(nd.path.dentry->d_inode, dentry, mode);
+ if (!err)
+ /* mark as kernel-created inode */
+ dentry->d_inode->i_private = &dev_mnt;
dput(dentry);
} else {
err = PTR_ERR(dentry);
}
- mutex_unlock(&nd.path.dentry->d_inode->i_mutex);

+ mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
path_put(&nd.path);
return err;
}

static int create_path(const char *nodepath)
{
- struct nameidata nd;
- int err = 0;
+ int err;

read_lock(&dirlock);
- err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,
- nodepath, LOOKUP_PARENT, &nd);
- if (err == 0) {
- struct dentry *dentry;
-
- /* create directory right away */
- dentry = lookup_create(&nd, 1);
- if (!IS_ERR(dentry)) {
- err = vfs_mkdir(nd.path.dentry->d_inode,
- dentry, 0755);
- dput(dentry);
- }
- mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
- path_put(&nd.path);
- } else if (err == -ENOENT) {
+ err = dev_mkdir(nodepath, 0755);
+ if (err == -ENOENT) {
char *path;
char *s;

@@ -129,7 +118,6 @@ static int create_path(const char *nodep
kfree(path);
}
read_unlock(&dirlock);
-
return err;
}

@@ -211,16 +199,21 @@ static int dev_rmdir(const char *name)
mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len);
if (!IS_ERR(dentry)) {
- if (dentry->d_inode)
- err = vfs_rmdir(nd.path.dentry->d_inode, dentry);
- else
+ if (dentry->d_inode) {
+ if (dentry->d_inode->i_private == &dev_mnt)
+ err = vfs_rmdir(nd.path.dentry->d_inode,
+ dentry);
+ else
+ err = -EPERM;
+ } else {
err = -ENOENT;
+ }
dput(dentry);
} else {
err = PTR_ERR(dentry);
}
- mutex_unlock(&nd.path.dentry->d_inode->i_mutex);

+ mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
path_put(&nd.path);
return err;
}