From: Dave Hansen <haveblue@us.ibm.com>
To: viro@ftp.linux.org.uk
Cc: serue@us.ibm.com, linux-kernel@vger.kernel.org,
Dave Hansen <haveblue@us.ibm.com>
Subject: [RFC][PATCH 22/27] sys_mknodat(): elevate write count for vfs_mknod/create()
Date: Wed, 12 Jul 2006 11:17:25 -0700 [thread overview]
Message-ID: <20060712181725.C28CC70F@localhost.localdomain> (raw)
In-Reply-To: <20060712181709.5C1A4353@localhost.localdomain>
This takes care of all of the direct callers of vfs_mknod().
Since a few of these cases also handle normal file creation
as well, this also covers some calls to vfs_create().
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
---
lxc-dave/fs/namei.c | 12 ++++++++++++
lxc-dave/fs/nfsd/vfs.c | 4 ++++
lxc-dave/net/unix/af_unix.c | 4 ++++
3 files changed, 20 insertions(+)
diff -puN fs/namei.c~C-elevate-writers-vfs_mknod-try2 fs/namei.c
--- lxc/fs/namei.c~C-elevate-writers-vfs_mknod-try2 2006-07-12 11:09:34.000000000 -0700
+++ lxc-dave/fs/namei.c 2006-07-12 11:09:39.000000000 -0700
@@ -1879,14 +1879,26 @@ asmlinkage long sys_mknodat(int dfd, con
if (!IS_ERR(dentry)) {
switch (mode & S_IFMT) {
case 0: case S_IFREG:
+ error = mnt_want_write(nd.mnt);
+ if (error)
+ break;
error = vfs_create(nd.dentry->d_inode,dentry,mode,&nd);
+ mnt_drop_write(nd.mnt);
break;
case S_IFCHR: case S_IFBLK:
+ error = mnt_want_write(nd.mnt);
+ if (error)
+ break;
error = vfs_mknod(nd.dentry->d_inode,dentry,mode,
new_decode_dev(dev));
+ mnt_drop_write(nd.mnt);
break;
case S_IFIFO: case S_IFSOCK:
+ error = mnt_want_write(nd.mnt);
+ if (error)
+ break;
error = vfs_mknod(nd.dentry->d_inode,dentry,mode,0);
+ mnt_drop_write(nd.mnt);
break;
case S_IFDIR:
error = -EPERM;
diff -puN fs/nfsd/vfs.c~C-elevate-writers-vfs_mknod-try2 fs/nfsd/vfs.c
--- lxc/fs/nfsd/vfs.c~C-elevate-writers-vfs_mknod-try2 2006-07-12 11:09:34.000000000 -0700
+++ lxc-dave/fs/nfsd/vfs.c 2006-07-12 11:09:39.000000000 -0700
@@ -1155,6 +1155,9 @@ nfsd_create(struct svc_rqst *rqstp, stru
/*
* Get the dir op function pointer.
*/
+ err = mnt_want_write(fhp->fh_export->ex_mnt);
+ if (err)
+ goto out_nfserr;
err = nfserr_perm;
switch (type) {
case S_IFREG:
@@ -1173,6 +1176,7 @@ nfsd_create(struct svc_rqst *rqstp, stru
printk("nfsd: bad file type %o in nfsd_create\n", type);
err = -EINVAL;
}
+ mnt_drop_write(fhp->fh_export->ex_mnt);
if (err < 0)
goto out_nfserr;
diff -puN net/unix/af_unix.c~C-elevate-writers-vfs_mknod-try2 net/unix/af_unix.c
--- lxc/net/unix/af_unix.c~C-elevate-writers-vfs_mknod-try2 2006-07-12 11:09:33.000000000 -0700
+++ lxc-dave/net/unix/af_unix.c 2006-07-12 11:09:39.000000000 -0700
@@ -822,7 +822,11 @@ static int unix_bind(struct socket *sock
*/
mode = S_IFSOCK |
(SOCK_INODE(sock)->i_mode & ~current->fs->umask);
+ err = mnt_want_write(nd.mnt);
+ if (err)
+ goto out_mknod_dput;
err = vfs_mknod(nd.dentry->d_inode, dentry, mode, 0);
+ mnt_drop_write(nd.mnt);
if (err)
goto out_mknod_dput;
mutex_unlock(&nd.dentry->d_inode->i_mutex);
_
next prev parent reply other threads:[~2006-07-12 18:20 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-07-12 18:17 [RFC][PATCH 00/27] Mount writer count and read-only bind mounts (v4) Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 01/27] prepare for write access checks: collapse if() Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 02/27] r/o bind mount prepwork: move open_namei()'s vfs_create() Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 04/27] reintroduce list of vfsmounts over superblock Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 03/27] unlink: monitor i_nlink Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 05/27] Add vfsmount writer count Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 06/27] record when sb_writer_count elevated for inode Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 07/27] kill open files traverse on remount ro Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 08/27] increment sb writer count when nlink hits zero Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 09/27] elevate writer count for chown and friends Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 10/27] elevate mnt writers for callers of vfs_mkdir() Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 11/27] elevate write count during entire ncp_ioctl() Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 12/27] sys_symlinkat() elevate write count around vfs_symlink() Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 13/27] elevate mount count for extended attributes Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 14/27] sys_linkat(): elevate write count around vfs_link() Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 15/27] mount_is_safe(): add comment Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 16/27] unix_find_other() elevate write count for touch_atime() Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 17/27] elevate write count over calls to vfs_rename() Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 18/27] tricky: elevate write count files are open()ed Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 19/27] elevate writer count for do_sys_truncate() Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 21/27] elevate write count for do_sys_utime() and touch_atime() Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 20/27] elevate write count for do_utimes() Dave Hansen
2006-07-12 18:17 ` Dave Hansen [this message]
2006-07-12 18:17 ` [RFC][PATCH 23/27] elevate mnt writers for vfs_unlink() callers Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 24/27] do_rmdir(): elevate write count Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 25/27] elevate writer count for custom 'struct file' Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 26/27] Originally from: Herbert Poetzl <herbert@13thfloor.at> Dave Hansen
2006-07-12 18:17 ` [RFC][PATCH 27/27] honor r/w changes at do_remount() time Dave Hansen
2006-07-13 7:04 ` [RFC][PATCH 00/27] Mount writer count and read-only bind mounts (v4) Ram Pai
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