Merge branch 'linus' into stackprotector

Conflicts:
	arch/x86/include/asm/pda.h
	kernel/fork.c

1 files changed, 118 insertions, 21 deletions

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index aa1d0d6489a1..d1c5f787b365 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -410,6 +410,7 @@ out_nfserr:
 static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf)
 {
 	ssize_t buflen;
+	ssize_t ret;
 
 	buflen = vfs_getxattr(dentry, key, NULL, 0);
 	if (buflen <= 0)
@@ -419,7 +420,10 @@ static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf)
 	if (!*buf)
 		return -ENOMEM;
 
-	return vfs_getxattr(dentry, key, *buf, buflen);
+	ret = vfs_getxattr(dentry, key, *buf, buflen);
+	if (ret < 0)
+		kfree(*buf);
+	return ret;
 }
 #endif
 
@@ -667,6 +671,7 @@ __be32
 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
 			int access, struct file **filp)
 {
+	const struct cred *cred = current_cred();
 	struct dentry	*dentry;
 	struct inode	*inode;
 	int		flags = O_RDONLY|O_LARGEFILE;
@@ -721,7 +726,7 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
 		DQUOT_INIT(inode);
 	}
 	*filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_path.mnt),
-				flags);
+			    flags, cred);
 	if (IS_ERR(*filp))
 		host_err = PTR_ERR(*filp);
 out_nfserr:
@@ -1165,7 +1170,7 @@ nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp,
 	 * send along the gid on create when it tries to implement
 	 * setgid directories via NFS:
 	 */
-	if (current->fsuid != 0)
+	if (current_fsuid() != 0)
 		iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
 	if (iap->ia_valid)
 		return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
@@ -1814,6 +1819,113 @@ out:
 }
 
 /*
+ * We do this buffering because we must not call back into the file
+ * system's ->lookup() method from the filldir callback. That may well
+ * deadlock a number of file systems.
+ *
+ * This is based heavily on the implementation of same in XFS.
+ */
+struct buffered_dirent {
+	u64		ino;
+	loff_t		offset;
+	int		namlen;
+	unsigned int	d_type;
+	char		name[];
+};
+
+struct readdir_data {
+	char		*dirent;
+	size_t		used;
+	int		full;
+};
+
+static int nfsd_buffered_filldir(void *__buf, const char *name, int namlen,
+				 loff_t offset, u64 ino, unsigned int d_type)
+{
+	struct readdir_data *buf = __buf;
+	struct buffered_dirent *de = (void *)(buf->dirent + buf->used);
+	unsigned int reclen;
+
+	reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
+	if (buf->used + reclen > PAGE_SIZE) {
+		buf->full = 1;
+		return -EINVAL;
+	}
+
+	de->namlen = namlen;
+	de->offset = offset;
+	de->ino = ino;
+	de->d_type = d_type;
+	memcpy(de->name, name, namlen);
+	buf->used += reclen;
+
+	return 0;
+}
+
+static int nfsd_buffered_readdir(struct file *file, filldir_t func,
+				 struct readdir_cd *cdp, loff_t *offsetp)
+{
+	struct readdir_data buf;
+	struct buffered_dirent *de;
+	int host_err;
+	int size;
+	loff_t offset;
+
+	buf.dirent = (void *)__get_free_page(GFP_KERNEL);
+	if (!buf.dirent)
+		return -ENOMEM;
+
+	offset = *offsetp;
+
+	while (1) {
+		unsigned int reclen;
+
+		cdp->err = nfserr_eof; /* will be cleared on successful read */
+		buf.used = 0;
+		buf.full = 0;
+
+		host_err = vfs_readdir(file, nfsd_buffered_filldir, &buf);
+		if (buf.full)
+			host_err = 0;
+
+		if (host_err < 0)
+			break;
+
+		size = buf.used;
+
+		if (!size)
+			break;
+
+		de = (struct buffered_dirent *)buf.dirent;
+		while (size > 0) {
+			offset = de->offset;
+
+			if (func(cdp, de->name, de->namlen, de->offset,
+				 de->ino, de->d_type))
+				goto done;
+
+			if (cdp->err != nfs_ok)
+				goto done;
+
+			reclen = ALIGN(sizeof(*de) + de->namlen,
+				       sizeof(u64));
+			size -= reclen;
+			de = (struct buffered_dirent *)((char *)de + reclen);
+		}
+		offset = vfs_llseek(file, 0, SEEK_CUR);
+	}
+
+ done:
+	free_page((unsigned long)(buf.dirent));
+
+	if (host_err)
+		return nfserrno(host_err);
+
+	*offsetp = offset;
+	return cdp->err;
+}
+
+/*
  * Read entries from a directory.
  * The  NFSv3/4 verifier we ignore for now.
  */
@@ -1822,7 +1934,6 @@ nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
 	     struct readdir_cd *cdp, filldir_t func)
 {
 	__be32		err;
-	int 		host_err;
 	struct file	*file;
 	loff_t		offset = *offsetp;
 
@@ -1836,21 +1947,7 @@ nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
 		goto out_close;
 	}
 
-	/*
-	 * Read the directory entries. This silly loop is necessary because
-	 * readdir() is not guaranteed to fill up the entire buffer, but
-	 * may choose to do less.
-	 */
-
-	do {
-		cdp->err = nfserr_eof; /* will be cleared on successful read */
-		host_err = vfs_readdir(file, func, cdp);
-	} while (host_err >=0 && cdp->err == nfs_ok);
-	if (host_err)
-		err = nfserrno(host_err);
-	else
-		err = cdp->err;
-	*offsetp = vfs_llseek(file, 0, 1);
+	err = nfsd_buffered_readdir(file, func, cdp, offsetp);
 
 	if (err == nfserr_eof || err == nfserr_toosmall)
 		err = nfs_ok; /* can still be found in ->err */
@@ -1905,7 +2002,7 @@ nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
 		IS_APPEND(inode)?	" append" : "",
 		__mnt_is_readonly(exp->ex_path.mnt)?	" ro" : "");
 	dprintk("      owner %d/%d user %d/%d\n",
-		inode->i_uid, inode->i_gid, current->fsuid, current->fsgid);
+		inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid());
 #endif
 
 	/* Normally we reject any write/sattr etc access on a read-only file
@@ -1948,7 +2045,7 @@ nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
 	 * with NFSv3.
 	 */
 	if ((acc & NFSD_MAY_OWNER_OVERRIDE) &&
-	    inode->i_uid == current->fsuid)
+	    inode->i_uid == current_fsuid())
 		return 0;
 
 	/* This assumes  NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */