From: Gunnar Beutner <gunnar@beutner.name>
Date: Tue, 11 Oct 2011 16:50:52 +0000 (-0700)
Subject: Fixed invalid resource re-use in file_find()
X-Git-Tag: spl-0.6.0-rc6~3
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=763b2f3b57af1febb0fd72c4976992e672a350b4;p=spl

Fixed invalid resource re-use in file_find()

File descriptors are a per-process resource. The same descriptor
in different processes can refer to different files. find_file()
incorrectly assumed that file descriptors are globally unique.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes ZFS issue #386
---

diff --git a/include/sys/vnode.h b/include/sys/vnode.h
index 7d655e5..36605ca 100644
--- a/include/sys/vnode.h
+++ b/include/sys/vnode.h
@@ -158,6 +158,7 @@ typedef struct vnode {
 
 typedef struct vn_file {
 	int		f_fd;		/* linux fd for lookup */
+	struct task_struct *f_task;	/* linux task this fd belongs to */
 	struct file	*f_file;	/* linux file struct */
 	atomic_t	f_ref;		/* ref count */
 	kmutex_t	f_lock;		/* struct lock */
diff --git a/module/spl/spl-vnode.c b/module/spl/spl-vnode.c
index c466431..1b5cc5a 100644
--- a/module/spl/spl-vnode.c
+++ b/module/spl/spl-vnode.c
@@ -511,7 +511,7 @@ file_find(int fd)
 	ASSERT(spin_is_locked(&vn_file_lock));
 
         list_for_each_entry(fp, &vn_file_list,  f_list) {
-		if (fd == fp->f_fd) {
+		if (fd == fp->f_fd && fp->f_task == current) {
 			ASSERT(atomic_read(&fp->f_ref) != 0);
                         return fp;
 		}
@@ -550,6 +550,7 @@ vn_getf(int fd)
 	mutex_enter(&fp->f_lock);
 
 	fp->f_fd = fd;
+	fp->f_task = current;
 	fp->f_offset = 0;
 	atomic_inc(&fp->f_ref);