On Tue, 2010-01-26 at 20:44 -0500, Jeff Angielski wrote:Artem Bityutskiy wrote:On Mon, 2010-01-25 at 23:48 -0600, Matt Mackall wrote:Matt's patch did not compile as written. I tried to implement what I think he was trying to do and created this patch (it seems to match the guts of what inode_setattr() was looking for):Hmm. I'd just as soon drop it entirely. Here's a patch. Herbert, youIt may brake other FSes expectations, theoretically, as well.
want to send this through your crypto tree?
random: drop weird m_time/a_time manipulation
No other driver does anything remotely like this that I know of except
for the tty drivers, and I can't see any reason for random/urandom to do
it. In fact, it's a (trivial, harmless) timing information leak. And
obviously, it generates power- and flash-cycle wasting I/O, especially
if combined with something like hwrngd. Also, it breaks ubifs's
expectations.
Signed-off-by: Matt Mackall <mpm@xxxxxxxxxxx>
diff -r 29db0c391ce8 drivers/char/random.c
--- a/drivers/char/random.c Sun Jan 17 11:01:16 2010 -0800
+++ b/drivers/char/random.c Mon Jan 25 23:32:00 2010 -0600
@@ -1051,12 +1051,6 @@
/* like a named pipe */
}
- /*
- * If we gave the user some bytes, update the access time.
- */
- if (count)
- file_accessed(file);
-
return (count ? count : retval);
}
@@ -1116,8 +1110,6 @@
if (ret)
return ret;
- inode->i_mtime = current_fs_time(inode->i_sb);
- mark_inode_dirty(inode);
return (ssize_t)count;
}
Anyway, I'm perfectly fine if this is removed.
Jeff, could you please try Matt's patch and report back if you still
have issues or not. If no, you can use this as a temporary work-around
until a proper fix hits upstream or ubifs-2.6.git.
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 8258982..70f16c7 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1108,6 +1108,7 @@ static ssize_t random_write(struct file *file, const char __user *buffer,
{
size_t ret;
struct inode *inode = file->f_path.dentry->d_inode;
+ struct iattr attr;
ret = write_pool(&blocking_pool, buffer, count);
if (ret)
@@ -1116,8 +1117,12 @@ static ssize_t random_write(struct file *file, const char __user *buffer,
if (ret)
return ret;
- inode->i_mtime = current_fs_time(inode->i_sb);
- mark_inode_dirty(inode);
+ attr.ia_mtime = current_fs_time(inode->i_sb);
+ attr.ia_valid = ATTR_MTIME;
+ ret = inode_setattr(inode, &attr);
+ if (ret)
+ return ret;
+
return (ssize_t)count;
}
However, this patch does not fix the problem. I still see the same errors. Matt, is this what you were trying to do?
That doesn't look anything like my patch? And mine was test compiled.