https://bugzilla.kernel.org/show_bug.cgi?id=15827 Summary: ext4_get_blocks may be called while ext4_truncate() is in progress Product: File System Version: 2.5 Kernel Version: v2.6.29-rc5 Platform: All OS/Version: Linux Tree: Mainline Status: NEW Severity: high Priority: P1 Component: ext4 AssignedTo: fs_ext4@xxxxxxxxxxxxxxxxxxxx ReportedBy: dmonakhov@xxxxxxxxxx Regression: No Created an attachment (id=26081) --> (https://bugzilla.kernel.org/attachment.cgi?id=26081) dmesg output During truncate we may need to restart new transaction, to avoid deadlock on i_data_sem it was dropped commit 487caeef9fc08c0565e082c40a8aaf58dad92bbb Author: Jan Kara <jack@xxxxxxx> Date: Mon Aug 17 22:17:20 2009 -0400 Jan given a good explanation why this approach would work, I have better explanation why this can't work work. Yes we have blocked all writers beyond i_size, but writers(flush, page_mkwrite) before i_size still may change node blocks, so 'path' which was lookup by truncate is not longer valid. So we are in big big troubles. I've add created inode's history tracer patch which spotted the issue. See attachments. --- Comment #1 from Dmitry Monakhov <dmonakhov@xxxxxxxxxx> 2010-04-21 15:41:13 --- Created an attachment (id=26082) --> (https://bugzilla.kernel.org/attachment.cgi?id=26082) debug patch against ext4.git/next + patches from bug #15792 The debug patch is rather ugly, but still useful. -- Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are watching the assignee of the bug. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
