Chunk 2:
Since all branches of do_mount() (mounting, binding, remounting)
do the same thing (lookup of directory) we can take that lookup in the
beginning of do_mount() and pass to do_loopback() and do_remount()
nameidata instead of name.
Please, apply
Al
diff -urN S6-pre1-do_remount/fs/super.c S6-pre1-do_mount/fs/super.c
--- S6-pre1-do_remount/fs/super.c Tue Jun 5 08:14:29 2001
+++ S6-pre1-do_mount/fs/super.c Tue Jun 5 08:15:33 2001
@@ -1151,9 +1151,9 @@
/*
* do loopback mount.
*/
-static int do_loopback(char *old_name, char *new_name)
+static int do_loopback(struct nameidata *nd, char *old_name)
{
- struct nameidata old_nd, new_nd;
+ struct nameidata old_nd;
int err = 0;
if (!old_name || !*old_name)
return -EINVAL;
@@ -1161,31 +1161,25 @@
err = path_walk(old_name, &old_nd);
if (err)
goto out;
- if (path_init(new_name, LOOKUP_POSITIVE, &new_nd))
- err = path_walk(new_name, &new_nd);
+ err = mount_is_safe(nd);
if (err)
goto out1;
- err = mount_is_safe(&new_nd);
- if (err)
- goto out2;
err = -EINVAL;
- if (S_ISDIR(new_nd.dentry->d_inode->i_mode) !=
+ if (S_ISDIR(nd->dentry->d_inode->i_mode) !=
S_ISDIR(old_nd.dentry->d_inode->i_mode))
- goto out2;
+ goto out1;
err = -ENOMEM;
down(&mount_sem);
/* there we go */
- down(&new_nd.dentry->d_inode->i_zombie);
- if (IS_DEADDIR(new_nd.dentry->d_inode))
+ down(&nd->dentry->d_inode->i_zombie);
+ if (IS_DEADDIR(nd->dentry->d_inode))
err = -ENOENT;
- else if (add_vfsmnt(&new_nd, old_nd.dentry, old_nd.mnt->mnt_devname))
+ else if (add_vfsmnt(nd, old_nd.dentry, old_nd.mnt->mnt_devname))
err = 0;
- up(&new_nd.dentry->d_inode->i_zombie);
+ up(&nd->dentry->d_inode->i_zombie);
up(&mount_sem);
-out2:
- path_release(&new_nd);
out1:
path_release(&old_nd);
out:
@@ -1198,25 +1192,15 @@
* on it - tough luck.
*/
-static int do_remount(const char *dir,int flags,char *data)
+static int do_remount(struct nameidata *nd, int flags, char *data)
{
- struct nameidata nd;
- int retval = 0;
-
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- if (path_init(dir, LOOKUP_FOLLOW|LOOKUP_POSITIVE, &nd))
- retval = path_walk(dir, &nd);
- if (retval)
- return retval;
-
- retval = -EINVAL;
- if (nd.dentry == nd.mnt->mnt_root)
- retval = do_remount_sb(nd.mnt->mnt_sb, flags, data);
+ if (nd->dentry != nd->mnt->mnt_root)
+ return -EINVAL;
- path_release(&nd);
- return retval;
+ return do_remount_sb(nd->mnt->mnt_sb, flags, data);
}
static int copy_mount_options (const void *data, unsigned long *where)
@@ -1286,38 +1270,41 @@
if (dev_name && !memchr(dev_name, 0, PAGE_SIZE))
return -EINVAL;
- /* OK, looks good, now let's see what do they want */
+ /* ... and get the mountpoint */
+ if (path_init(dir_name, LOOKUP_FOLLOW|LOOKUP_POSITIVE, &nd))
+ retval = path_walk(dir_name, &nd);
+ if (retval)
+ return retval;
/* just change the flags? - capabilities are checked in do_remount() */
- if (flags & MS_REMOUNT)
- return do_remount(dir_name, flags & ~MS_REMOUNT,
- (char *) data_page);
+ if (flags & MS_REMOUNT) {
+ retval = do_remount(&nd, flags&~MS_REMOUNT, (char *)data_page);
+ goto nd_out;
+ }
/* "mount --bind"? Equivalent to older "mount -t bind" */
/* No capabilities? What if users do thousands of these? */
- if (flags & MS_BIND)
- return do_loopback(dev_name, dir_name);
+ if (flags & MS_BIND) {
+ retval = do_loopback(&nd, dev_name);
+ goto nd_out;
+ }
/* For the rest we need the type */
+ retval = -EINVAL;
if (!type_page || !memchr(type_page, 0, PAGE_SIZE))
- return -EINVAL;
+ goto nd_out;
+ retval = -EPERM;
/* for the rest we _really_ need capabilities... */
if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
+ goto nd_out;
+ retval = -ENODEV;
/* ... filesystem driver... */
fstype = get_fs_type(type_page);
if (!fstype)
- return -ENODEV;
-
- /* ... and mountpoint. Do the lookup first to force automounting. */
- if (path_init(dir_name,
- LOOKUP_FOLLOW|LOOKUP_POSITIVE|LOOKUP_DIRECTORY, &nd))
- retval = path_walk(dir_name, &nd);
- if (retval)
- goto fs_out;
+ goto nd_out;
/* get superblock, locks mount_sem on success */
if (fstype->fs_flags & FS_NOMOUNT)
@@ -1331,7 +1318,7 @@
retval = PTR_ERR(sb);
if (IS_ERR(sb))
- goto dput_out;
+ goto fs_out;
/* Something was mounted here while we slept */
while(d_mountpoint(nd.dentry) && follow_down(&nd.mnt, &nd.dentry))
@@ -1346,6 +1333,9 @@
retval = -ENOENT;
if (!nd.dentry->d_inode)
goto fail;
+ retval = -ENOTDIR;
+ if (!S_ISDIR(nd.dentry->d_inode->i_mode))
+ goto fail;
down(&nd.dentry->d_inode->i_zombie);
if (!IS_DEADDIR(nd.dentry->d_inode)) {
retval = -ENOMEM;
@@ -1357,10 +1347,10 @@
retval = 0;
unlock_out:
up(&mount_sem);
-dput_out:
- path_release(&nd);
fs_out:
put_filesystem(fstype);
+nd_out:
+ path_release(&nd);
return retval;
fail:
-
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