Fix i_mutex vs. readdir handling in nfsd

[safe/jmp/linux-2.6] / fs / namei.c

diff --git a/fs/namei.c b/fs/namei.c
index 1928197..78f253c 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -32,6 +32,7 @@
 #include <linux/file.h>
 #include <linux/fcntl.h>
 #include <linux/device_cgroup.h>
+#include <linux/fs_struct.h>
 #include <asm/uaccess.h>
 
 #define ACC_MODE(x) ("\000\004\002\006"[(x)&O_ACCMODE])
@@ -1247,6 +1248,8 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
        int err;
        struct qstr this;
 
+       WARN_ON_ONCE(!mutex_is_locked(&base->d_inode->i_mutex));
+
        err = __lookup_one_len(name, &this, base, len);
        if (err)
                return ERR_PTR(err);
@@ -1489,24 +1492,22 @@ int may_open(struct path *path, int acc_mode, int flag)
        if (!inode)
                return -ENOENT;
 
-       if (S_ISLNK(inode->i_mode))
+       switch (inode->i_mode & S_IFMT) {
+       case S_IFLNK:
                return -ELOOP;
-       
-       if (S_ISDIR(inode->i_mode) && (acc_mode & MAY_WRITE))
-               return -EISDIR;
-
-       /*
-        * FIFO's, sockets and device files are special: they don't
-        * actually live on the filesystem itself, and as such you
-        * can write to them even if the filesystem is read-only.
-        */
-       if (S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
-               flag &= ~O_TRUNC;
-       } else if (S_ISBLK(inode->i_mode) || S_ISCHR(inode->i_mode)) {
+       case S_IFDIR:
+               if (acc_mode & MAY_WRITE)
+                       return -EISDIR;
+               break;
+       case S_IFBLK:
+       case S_IFCHR:
                if (path->mnt->mnt_flags & MNT_NODEV)
                        return -EACCES;
-
+               /*FALLTHRU*/
+       case S_IFIFO:
+       case S_IFSOCK:
                flag &= ~O_TRUNC;
+               break;
        }
 
        error = inode_permission(inode, acc_mode);
@@ -1580,7 +1581,7 @@ static int __open_namei_create(struct nameidata *nd, struct path *path,
        struct dentry *dir = nd->path.dentry;
 
        if (!IS_POSIXACL(dir->d_inode))
-               mode &= ~current->fs->umask;
+               mode &= ~current_umask();
        error = security_path_mknod(&nd->path, path->dentry, mode, 0);
        if (error)
                goto out_unlock;
@@ -1991,7 +1992,7 @@ SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, int, mode,
                goto out_unlock;
        }
        if (!IS_POSIXACL(nd.path.dentry->d_inode))
-               mode &= ~current->fs->umask;
+               mode &= ~current_umask();
        error = may_mknod(mode);
        if (error)
                goto out_dput;
@@ -2069,7 +2070,7 @@ SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, int, mode)
                goto out_unlock;
 
        if (!IS_POSIXACL(nd.path.dentry->d_inode))
-               mode &= ~current->fs->umask;
+               mode &= ~current_umask();
        error = mnt_want_write(nd.path.mnt);
        if (error)
                goto out_dput;
@@ -2899,10 +2900,3 @@ EXPORT_SYMBOL(vfs_symlink);
 EXPORT_SYMBOL(vfs_unlink);
 EXPORT_SYMBOL(dentry_unhash);
 EXPORT_SYMBOL(generic_readlink);
-
-/* to be mentioned only in INIT_TASK */
-struct fs_struct init_fs = {
-       .count          = ATOMIC_INIT(1),
-       .lock           = __RW_LOCK_UNLOCKED(init_fs.lock),
-       .umask          = 0022,
-};