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From: Dave Hansen <haveblue@us.ibm.com>
To: linux-fsdevel@vger.kernel.org
Cc: herbert@13thfloor.at, viro@ftp.linux.org.uk, hch@infradead.org,
	trond.myklebust@fys.uio.no, Dave Hansen <haveblue@us.ibm.com>
Subject: [RFC][PATCH 22/27] sys_mknodat(): elevate write count for vfs_mknod/create()
Date: Wed, 07 Jun 2006 17:10:35 -0700	[thread overview]
Message-ID: <20060608001035.559326ED@localhost.localdomain> (raw)
In-Reply-To: <20060608001013.0D041507@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>
---

 ipc/mqueue.c                |    0 
 lxc-dave/fs/namei.c         |   48 ++++++++++++++++++++++++++++----------------
 lxc-dave/fs/nfsd/vfs.c      |    4 +++
 lxc-dave/net/unix/af_unix.c |    4 +++
 4 files changed, 39 insertions(+), 17 deletions(-)

diff -puN fs/namei.c~elevate-writers-vfs_mknod-try2 fs/namei.c
--- lxc/fs/namei.c~elevate-writers-vfs_mknod-try2	2006-06-07 16:53:25.000000000 -0700
+++ lxc-dave/fs/namei.c	2006-06-07 16:53:25.000000000 -0700
@@ -1852,26 +1852,40 @@ asmlinkage long sys_mknodat(int dfd, con
 
 	if (!IS_POSIXACL(nd.dentry->d_inode))
 		mode &= ~current->fs->umask;
-	if (!IS_ERR(dentry)) {
-		switch (mode & S_IFMT) {
-		case 0: case S_IFREG:
-			error = vfs_create(nd.dentry->d_inode,dentry,mode,&nd);
-			break;
-		case S_IFCHR: case S_IFBLK:
-			error = vfs_mknod(nd.dentry->d_inode,dentry,mode,
-					new_decode_dev(dev));
-			break;
-		case S_IFIFO: case S_IFSOCK:
-			error = vfs_mknod(nd.dentry->d_inode,dentry,mode,0);
+	if (IS_ERR(dentry))
+		goto out_unlock;
+	error = mnt_want_write(nd.mnt);
+	if (error)
+		goto out_dput;
+	switch (mode & S_IFMT) {
+	case 0: case S_IFREG:
+		error = vfs_create(nd.dentry->d_inode,dentry,mode,&nd);
+		break;
+	case S_IFCHR: case S_IFBLK:
+		error = mnt_want_write(nd.mnt);
+		if (error)
 			break;
-		case S_IFDIR:
-			error = -EPERM;
+		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;
-		default:
-			error = -EINVAL;
-		}
-		dput(dentry);
+		error = vfs_mknod(nd.dentry->d_inode,dentry,mode,0);
+		mnt_drop_write(nd.mnt);
+		break;
+	case S_IFDIR:
+		error = -EPERM;
+		break;
+	default:
+		error = -EINVAL;
 	}
+	mnt_drop_write(nd.mnt);
+out_dput:
+	dput(dentry);
+out_unlock:
 	mutex_unlock(&nd.dentry->d_inode->i_mutex);
 	path_release(&nd);
 out:
diff -puN fs/nfsd/vfs.c~elevate-writers-vfs_mknod-try2 fs/nfsd/vfs.c
--- lxc/fs/nfsd/vfs.c~elevate-writers-vfs_mknod-try2	2006-06-07 16:53:25.000000000 -0700
+++ lxc-dave/fs/nfsd/vfs.c	2006-06-07 16:53:25.000000000 -0700
@@ -1153,6 +1153,9 @@ 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:
@@ -1171,6 +1174,7 @@ 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~elevate-writers-vfs_mknod-try2 net/unix/af_unix.c
--- lxc/net/unix/af_unix.c~elevate-writers-vfs_mknod-try2	2006-06-07 16:53:25.000000000 -0700
+++ lxc-dave/net/unix/af_unix.c	2006-06-07 16:53:25.000000000 -0700
@@ -789,7 +789,11 @@ 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);
diff -puN ipc/mqueue.c~elevate-writers-vfs_mknod-try2 ipc/mqueue.c
diff -L xattr.patch -puN /dev/null /dev/null
_

  parent reply	other threads:[~2006-06-08  0:10 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-06-08  0:10 [RFC][PATCH 00/27] Read-only bind mounts Dave Hansen
2006-06-08  0:10 ` [RFC][PATCH 01/27] Add vfsmount writer count Dave Hansen
2006-06-08 10:33   ` Herbert Poetzl
2006-06-08  0:10 ` [RFC][PATCH 02/27] vfs_rmdir: change if() into goto Dave Hansen
2006-06-08 10:37   ` Herbert Poetzl
2006-06-08  0:10 ` [RFC][PATCH 03/27] do_rmdir(): elevate write count Dave Hansen
2006-06-08 10:42   ` Herbert Poetzl
2006-06-08 15:04     ` Dave Hansen
2006-06-08  0:10 ` [RFC][PATCH 04/27] elevate mnt writers for vfs_unlink() callers Dave Hansen
2006-06-08  0:10 ` [RFC][PATCH 05/27] elevate mnt writers for nfsd caller of vfs_mkdir() Dave Hansen
2006-06-08  0:10 ` [RFC][PATCH 06/27] elevate write count during entire ncp_ioctl() Dave Hansen
2006-06-08 10:44   ` Herbert Poetzl
2006-06-08 15:07     ` Dave Hansen
2006-06-08  0:10 ` [RFC][PATCH 07/27] sys_mkdirat(): collapse if() Dave Hansen
2006-06-08 10:46   ` Herbert Poetzl
2006-06-08 15:10     ` Dave Hansen
2006-06-08 15:54       ` Herbert Poetzl
2006-06-08  0:10 ` [RFC][PATCH 09/27] elevate mnt writers for sys_mkdirat() call of vfs_mkdir() Dave Hansen
2006-06-08  0:10 ` [RFC][PATCH 08/27] sys_mkdirat(): one more goto Dave Hansen
2006-06-08 10:48   ` Herbert Poetzl
2006-06-08  0:10 ` [RFC][PATCH 10/27] sys_symlinkat() collapse if()s Dave Hansen
2006-06-08  0:10 ` [RFC][PATCH 11/27] sys_symlinkat() collapse one more if () Dave Hansen
2006-06-08 10:49   ` Herbert Poetzl
2006-06-08  0:10 ` [RFC][PATCH 12/27] sys_symlinkat() elevate write count around vfs_symlink() Dave Hansen
2006-06-08  0:10 ` [RFC][PATCH 13/27] sys_linkat(): elevate write count around vfs_link() Dave Hansen
2006-06-08  0:10 ` [RFC][PATCH 14/27] tricky: elevate write count files are open()ed Dave Hansen
2006-06-08 10:54   ` Herbert Poetzl
2006-06-08 15:12     ` Dave Hansen
2006-06-08 16:07       ` Herbert Poetzl
2006-06-08  0:10 ` [RFC][PATCH 15/27] elevate writer count for do_sys_truncate() Dave Hansen
2006-06-08  0:10 ` [RFC][PATCH 16/27] elevate write count for do_sys_utime() Dave Hansen
2006-06-08  0:10 ` [RFC][PATCH 17/27] elevate write count for do_utimes() Dave Hansen
2006-06-08  0:10 ` [RFC][PATCH 19/27] sys_faccessat() elevate writer count Dave Hansen
2006-06-08 11:03   ` Herbert Poetzl
2006-06-08 15:15     ` Dave Hansen
2006-06-08  0:10 ` [RFC][PATCH 18/27] sys_faccessat(): collapse if() Dave Hansen
2006-06-08 11:05   ` Herbert Poetzl
2006-06-08  0:10 ` [RFC][PATCH 20/27] unix_find_other() elevate write count for touch_atime() Dave Hansen
2006-06-08 11:07   ` Herbert Poetzl
2006-06-08  0:10 ` [RFC][PATCH 21/27] mount_is_safe(): add comment Dave Hansen
2006-06-08  0:10 ` Dave Hansen [this message]
2006-06-08 11:16   ` [RFC][PATCH 22/27] sys_mknodat(): elevate write count for vfs_mknod/create() Herbert Poetzl
2006-06-08 15:23     ` Dave Hansen
2006-06-08  0:10 ` [RFC][PATCH 23/27] elevate write count over calls to vfs_rename() Dave Hansen
2006-06-08 11:23   ` Herbert Poetzl
2006-06-08 15:24     ` Dave Hansen
2006-06-12 18:18   ` Al Viro
2006-06-12 18:29     ` Dave Hansen
2006-06-12 19:03       ` Al Viro
2006-06-08  0:10 ` [RFC][PATCH 24/27] elevate mount count for extended attributes Dave Hansen
2006-06-08  0:10 ` [RFC][PATCH 25/27] /proc/mounts: prep for flags from sb or mnt Dave Hansen
2006-06-08 11:25   ` Herbert Poetzl
2006-06-08  0:10 ` [RFC][PATCH 26/27] /proc/mounts: treat ro/rw like the rest Dave Hansen
2006-06-08 11:26   ` Herbert Poetzl
2006-06-08  0:10 ` [RFC][PATCH 27/27] create and pass read-only mnt flag into do_loopback() Dave Hansen

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