linux-kernel - [PATCH v1 05/12] vfs: fix mknodat to retry on ESTALE errors

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 26 Apr 2012 11:57:16 -0400
From:	Jeff Layton <jlayton@...hat.com>
To:	viro@...IV.linux.org.uk
Cc:	linux-fsdevel@...r.kernel.org, linux-nfs@...r.kernel.org,
	linux-kernel@...r.kernel.org, miklos@...redi.hu, hch@...radead.org,
	michael.brantley@...haw.com
Subject: [PATCH v1 05/12] vfs: fix mknodat to retry on ESTALE errors

Signed-off-by: Jeff Layton <jlayton@...hat.com>
---
 fs/namei.c |   62 ++++++++++++++++++++++++++++++-----------------------------
 1 files changed, 32 insertions(+), 30 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 367b0f2..9ee6b4e 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2581,44 +2581,46 @@ SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, umode_t, mode,
 	struct dentry *dentry;
 	struct path path;
 	int error;
+	unsigned int try = 0;
 
 	if (S_ISDIR(mode))
 		return -EPERM;
 
-	dentry = user_path_create(dfd, filename, &path, false, false);
-	if (IS_ERR(dentry))
-		return PTR_ERR(dentry);
+	do {
+		dentry = user_path_create(dfd, filename, &path, false, try);
+		if (IS_ERR(dentry))
+			return PTR_ERR(dentry);
 
-	if (!IS_POSIXACL(path.dentry->d_inode))
-		mode &= ~current_umask();
-	error = may_mknod(mode);
-	if (error)
-		goto out_dput;
-	error = mnt_want_write(path.mnt);
-	if (error)
-		goto out_dput;
-	error = security_path_mknod(&path, dentry, mode, dev);
-	if (error)
-		goto out_drop_write;
-	switch (mode & S_IFMT) {
-		case 0: case S_IFREG:
-			error = vfs_create(path.dentry->d_inode,dentry,mode,NULL);
-			break;
-		case S_IFCHR: case S_IFBLK:
-			error = vfs_mknod(path.dentry->d_inode,dentry,mode,
-					new_decode_dev(dev));
-			break;
-		case S_IFIFO: case S_IFSOCK:
-			error = vfs_mknod(path.dentry->d_inode,dentry,mode,0);
+		if (!IS_POSIXACL(path.dentry->d_inode))
+			mode &= ~current_umask();
+		error = may_mknod(mode);
+		if (error)
+			goto out_dput;
+		error = mnt_want_write(path.mnt);
+		if (error)
+			goto out_dput;
+		error = security_path_mknod(&path, dentry, mode, dev);
+		if (error)
+			goto out_drop_write;
+		switch (mode & S_IFMT) {
+			case 0: case S_IFREG:
+				error = vfs_create(path.dentry->d_inode, dentry, mode, NULL);
+				break;
+			case S_IFCHR: case S_IFBLK:
+				error = vfs_mknod(path.dentry->d_inode, dentry, mode,
+						new_decode_dev(dev));
+				break;
+			case S_IFIFO: case S_IFSOCK:
+				error = vfs_mknod(path.dentry->d_inode, dentry, mode, 0);
 			break;
-	}
+		}
 out_drop_write:
-	mnt_drop_write(path.mnt);
+		mnt_drop_write(path.mnt);
 out_dput:
-	dput(dentry);
-	mutex_unlock(&path.dentry->d_inode->i_mutex);
-	path_put(&path);
-
+		dput(dentry);
+		mutex_unlock(&path.dentry->d_inode->i_mutex);
+		path_put(&path);
+	} while (retry_estale(error, try++));
 	return error;
 }
 
-- 
1.7.7.6

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/