;
; Bind Mount Extensions
;
; This part adds mnt_may_create() and mnt_may_unlink() checks
; and uses them in lookup_create(), sys_rmdir() and sys_unlink()
; it also adds a RDONLY check to generic_write_checks() and
; for pipe_writev()
;
; Copyright (C) 2003-2005 Herbert Pötzl <[EMAIL PROTECTED]>
;
; Changelog:
;
; 0.01 - broken out part from bme0.05
;
; this patch is free software; you can redistribute it and/or
; modify it under the terms of the GNU General Public License
; as published by the Free Software Foundation; either version 2
; of the License, or (at your option) any later version.
;
; this patch is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
; GNU General Public License for more details.
;
diff -NurpP --minimal linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01/fs/namei.c
linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01/fs/namei.c
--- linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01/fs/namei.c 2005-02-13
17:16:55 +0100
+++ linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01/fs/namei.c
2005-02-19 06:31:50 +0100
@@ -1168,6 +1168,24 @@ static inline int may_create(struct inod
return permission(dir,MAY_WRITE | MAY_EXEC, nd);
}
+static inline int mnt_may_create(struct vfsmount *mnt, struct inode *dir,
struct dentry *child) {
+ if (child->d_inode)
+ return -EEXIST;
+ if (IS_DEADDIR(dir))
+ return -ENOENT;
+ if (MNT_IS_RDONLY(mnt))
+ return -EROFS;
+ return 0;
+}
+
+static inline int mnt_may_unlink(struct vfsmount *mnt, struct inode *dir,
struct dentry *child) {
+ if (!child->d_inode)
+ return -ENOENT;
+ if (MNT_IS_RDONLY(mnt))
+ return -EROFS;
+ return 0;
+}
+
/*
* Special case: O_CREAT|O_EXCL implies O_NOFOLLOW for security
* reasons.
@@ -1518,23 +1536,28 @@ do_link:
struct dentry *lookup_create(struct nameidata *nd, int is_dir)
{
struct dentry *dentry;
+ int error;
down(&nd->dentry->d_inode->i_sem);
- dentry = ERR_PTR(-EEXIST);
+ error = -EEXIST;
if (nd->last_type != LAST_NORM)
- goto fail;
+ goto out;
nd->flags &= ~LOOKUP_PARENT;
dentry = lookup_hash(&nd->last, nd->dentry);
if (IS_ERR(dentry))
+ goto ret;
+ error = mnt_may_create(nd->mnt, nd->dentry->d_inode, dentry);
+ if (error)
goto fail;
+ error = -ENOENT;
if (!is_dir && nd->last.name[nd->last.len] && !dentry->d_inode)
- goto enoent;
+ goto fail;
+ret:
return dentry;
-enoent:
- dput(dentry);
- dentry = ERR_PTR(-ENOENT);
fail:
- return dentry;
+ dput(dentry);
+out:
+ return ERR_PTR(error);
}
int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
@@ -1763,7 +1786,11 @@ asmlinkage long sys_rmdir(const char __u
dentry = lookup_hash(&nd.last, nd.dentry);
error = PTR_ERR(dentry);
if (!IS_ERR(dentry)) {
+ error = mnt_may_unlink(nd.mnt, nd.dentry->d_inode, dentry);
+ if (error)
+ goto exit2;
error = vfs_rmdir(nd.dentry->d_inode, dentry);
+ exit2:
dput(dentry);
}
up(&nd.dentry->d_inode->i_sem);
@@ -1835,6 +1862,9 @@ asmlinkage long sys_unlink(const char __
/* Why not before? Because we want correct error value */
if (nd.last.name[nd.last.len])
goto slashes;
+ error = mnt_may_unlink(nd.mnt, nd.dentry->d_inode, dentry);
+ if (error)
+ goto exit2;
inode = dentry->d_inode;
if (inode)
atomic_inc(&inode->i_count);
diff -NurpP --minimal linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01/fs/pipe.c
linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01/fs/pipe.c
--- linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01/fs/pipe.c 2005-02-13
17:16:58 +0100
+++ linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01/fs/pipe.c
2005-02-19 06:31:50 +0100
@@ -334,7 +334,7 @@ out:
wake_up_interruptible(PIPE_WAIT(*inode));
kill_fasync(PIPE_FASYNC_READERS(*inode), SIGIO, POLL_IN);
}
- if (ret > 0)
+ if ((ret > 0) && !MNT_IS_RDONLY(filp->f_vfsmnt))
inode_update_time(inode, 1); /* mtime and ctime */
return ret;
}
diff -NurpP --minimal
linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01/mm/filemap.c
linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01/mm/filemap.c
--- linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01/mm/filemap.c 2005-02-13
17:17:15 +0100
+++ linux-2.6.11-rc4-bme0.06-bm0.01-at0.01-cc0.01-co0.01/mm/filemap.c
2005-02-19 06:31:50 +0100
@@ -1810,6 +1810,8 @@ inline int generic_write_checks(struct f
}
if (!isblk) {
+ if (MNT_IS_RDONLY(file->f_vfsmnt))
+ return -EROFS;
/* FIXME: this is for backwards compatibility with 2.4 */
if (file->f_flags & O_APPEND)
*pos = i_size_read(inode);
-
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