On Thu, 2011-01-27 at 14:53 +1100, Dave Chinner wrote: > From: Dave Chinner <dchinner@xxxxxxxxxx> > > After test 139, kmemleak shows: > > unreferenced object 0xffff880078b405d8 (size 400): > comm "xfs_io", pid 4904, jiffies 4294909383 (age 1186.728s) > hex dump (first 32 bytes): > 60 c1 17 79 00 88 ff ff 60 c1 17 79 00 88 ff ff `..y....`..y.... > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > backtrace: > [<ffffffff81afb04d>] kmemleak_alloc+0x2d/0x60 > [<ffffffff8115c6cf>] kmem_cache_alloc+0x13f/0x2b0 > [<ffffffff814aaa97>] kmem_zone_alloc+0x77/0xf0 > [<ffffffff814aab2e>] kmem_zone_zalloc+0x1e/0x50 > [<ffffffff8147cd6b>] xfs_efi_init+0x4b/0xb0 > [<ffffffff814a4ee8>] xfs_trans_get_efi+0x58/0x90 > [<ffffffff81455fab>] xfs_bmap_finish+0x8b/0x1d0 > [<ffffffff814851b4>] xfs_itruncate_finish+0x2c4/0x5d0 > [<ffffffff814a970f>] xfs_setattr+0x8df/0xa70 > [<ffffffff814b5c7b>] xfs_vn_setattr+0x1b/0x20 > [<ffffffff8117dc00>] notify_change+0x170/0x2e0 > [<ffffffff81163bf6>] do_truncate+0x66/0xa0 > [<ffffffff81163d0b>] sys_ftruncate+0xdb/0xe0 > [<ffffffff8103a002>] system_call_fastpath+0x16/0x1b > [<ffffffffffffffff>] 0xffffffffffffffff > > The cause of the leak is that the "remove" parameter of IOP_UNPIN() > is never set when a CIL push is aborted. This means that the EFI > item is never freed if it was in the push being cancelled. The > problem is specific to delayed logging, but has uncovered a couple > of problems with the handling of IOP_UNPIN(remove). > > Firstly, we cannot safely call xfs_trans_del_item() from IOP_UNPIN() > in the CIL commit failure path or the iclog write failure path > because for delayed loging we have no transaction context. Hence we > must only call xfs_trans_del_item() if the log item being unpinned > has an active log item descriptor. > > Secondly, xfs_trans_uncommit() does not handle log item descriptor > freeing during the traversal of log items on a transaction. It can > reference a freed log item descriptor when unpinning an EFI item. > Hence it needs to use a safe list traversal method to allow items to > be removed from the transaction during IOP_UNPIN(). > > Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx> OK, this looks good. Reviewed-by: Alex Elder <aelder@xxxxxxx> _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
