On Sat, Nov 24, 2007 at 12:47:21AM +0100, Rafael J. Wysocki wrote: > On Thursday, 22 of November 2007, Jeremy Fitzhardinge wrote: > > It seems that a process blocked in a write to an xfs filesystem due to > > xfs_freeze cannot be frozen by the freezer. > > The freezer doesn't handle tasks in TASK_UNINTERRUPTIBLE and I don't know how > to make it handle them without at least partially defeating its purpose.
So how do you handle threads that are blocked on I/O or a lock during the system freeze process, then? > > I see this if I suspend my laptop while doing something xfs-filesystem > > intensive, like a kernel build. My suspend scripts freeze the XFS > > filesystem (as Dave said I should), which presumably blocks some writer, > > and then the freezer times out and fails to complete. > > > > Here's part of the process dump the freezer does when it times out: > > > > cc1 D 00000000 0 18138 18137 > > dd5f1e24 00200082 00000002 00000000 ecdeeb00 ecdeec64 c200f280 > > 00000001 > > 009c09a0 dd5f1e0c dd5f1e0c 0000000f 00000000 00000000 00000000 > > dd5f1e74 > > c7beb480 dd5f1e88 dd5f1ea8 c0228d97 e8889540 dd5f1e38 c015b75d > > dd5f1e44 > > Call Trace: > > [<c0228d97>] xfs_write+0xf4/0x6d9 > > [<c0226038>] xfs_file_aio_write+0x53/0x5b > > [<c0171c15>] do_sync_write+0xae/0xec > > [<c0172343>] vfs_write+0xa4/0x120 > > [<c01728d7>] sys_write+0x3b/0x60 > > [<c0106fae>] sysenter_past_esp+0x6b/0xa1 > > ======================= > > > > > > I haven't looked at how to fix this yet. I only just worked out why I > > was getting suspend failures. > > Well, you can add freezer_do_not_count()/freezer_count() annotations to > xfs_write() (and whatever else is blocked as a result of the XFS being > frozen). May as well annotate the whole VFS, then, because once the transaction subsystem is frozen any operation that modifies the filesystem will get blocked like this. Cheers, Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
