Messages in this thread Patch in this message | | | Subject | Re: UBIFS assert failed in ubifs_dirty_inode | From | Matt Mackall <> | Date | Mon, 25 Jan 2010 23:48:48 -0600 |
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On Tue, 2010-01-26 at 06:40 +0200, Artem Bityutskiy wrote: > On Thu, 2010-01-21 at 22:03 -0500, Jeff Angielski wrote: > > I am trying use an UBIFS root filesystem on my PowerPC MPC8544 but I am > > seeing some intermitent problems with "UBIFS assert failed in > > ubifs_dirty_inode" errors. > > > > On the first boot after I program the NAND with a fresh UBI image, > > everything seems to work ok. > > > > After that, on subsequent powercycles or reboots, I sometimes see a boot > > with the following error: > > > > [ 5.984232] UBIFS assert failed in ubifs_dirty_inode at 377 (pid 1011) > > Interesting. > > The stack trace for this assertion is: > > [ 42.724193] [df121e60] [c00070f8] show_stack+0x3c/0x17c (unreliable) > [ 42.730566] [df121ea0] [c017e754] ubifs_dirty_inode+0xe0/0xe4 > [ 42.736325] [df121eb0] [c00c6fbc] __mark_inode_dirty+0x3c/0x16c > [ 42.742260] [df121ec0] [c01f9034] random_write+0x8c/0xa4 > [ 42.747584] [df121ef0] [c00a4d2c] vfs_write+0xb4/0x184 > [ 42.752730] [df121f10] [c00a53e8] sys_write+0x4c/0x90 > [ 42.757795] [df121f40] [c000fd48] ret_from_syscall+0x0/0x3c > > Which leads us to > > ~/git/linux-2.6/drivers/char/random.c, where we can find this code: > > inode->i_mtime = current_fs_time(inode->i_sb); > mark_inode_dirty(inode); > return (ssize_t)count; > > which is the reason for the assertion and for the further budgeting > screw-up. > > The thing is that UBIFS has to allocate budget every-time a clean inode > is made dirty. But the 'random' driver bypasses UBIFS budget allocation, > and instead, changes mtime directly and marks the inode as dirty > directly. > > The driver should instead call the ->setattr() method of the inode, > which should do the right thing. IOW, something like this is needed: > > diff --git a/drivers/char/random.c b/drivers/char/random.c > index 8258982..f911781 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; > > ret = write_pool(&blocking_pool, buffer, count); > if (ret) > @@ -1116,8 +1117,11 @@ 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); > + iattr->i_mtime = current_fs_time(inode->i_sb); > + iattr->ia_valid = ATTR_ATIME; > + ret = inode_setattr(inode, &attr); > + if (ret) > + return ret; > return (ssize_t)count; > } > > Note - I did not even compile-test this. Would you try that please :-)
Hmm. I'd just as soon drop it entirely. Here's a patch. Herbert, you 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@selenic.com>
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; } -- http://selenic.com : development and support for Mercurial and Linux
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