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authorDan Williams <dan.j.williams@intel.com>2007-11-14 19:59:35 -0500
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-11-14 21:45:39 -0500
commit6c55be8b962f1bdc592d579e81fc27b11ea53dfc (patch)
tree3413cc2c8e26afdbc498cbdbd96bc2fa9733b2a6 /drivers
parent5b23dbe8173c212d6a326e35347b038705603d39 (diff)
raid5: fix unending write sequence
<debug output from Joel's system> handling stripe 7629696, state=0x14 cnt=1, pd_idx=2 ops=0:0:0 check 5: state 0x6 toread 0000000000000000 read 0000000000000000 write fffff800ffcffcc0 written 0000000000000000 check 4: state 0x6 toread 0000000000000000 read 0000000000000000 write fffff800fdd4e360 written 0000000000000000 check 3: state 0x1 toread 0000000000000000 read 0000000000000000 write 0000000000000000 written 0000000000000000 check 2: state 0x1 toread 0000000000000000 read 0000000000000000 write 0000000000000000 written 0000000000000000 check 1: state 0x6 toread 0000000000000000 read 0000000000000000 write fffff800ff517e40 written 0000000000000000 check 0: state 0x6 toread 0000000000000000 read 0000000000000000 write fffff800fd4cae60 written 0000000000000000 locked=4 uptodate=2 to_read=0 to_write=4 failed=0 failed_num=0 for sector 7629696, rmw=0 rcw=0 </debug> These blocks were prepared to be written out, but were never handled in ops_run_biodrain(), so they remain locked forever. The operations flags are all clear which means handle_stripe() thinks nothing else needs to be done. This state suggests that the STRIPE_OP_PREXOR bit was sampled 'set' when it should not have been. This patch cleans up cases where the code looks at sh->ops.pending when it should be looking at the consistent stack-based snapshot of the operations flags. Report from Joel: Resync done. Patch fix this bug. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Joel Bertrand <joel.bertrand@systella.fr> Cc: <stable@kernel.org> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/md/raid5.c16
1 files changed, 9 insertions, 7 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 1cfc984cc7b7..a5aad8cad843 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -688,7 +688,8 @@ ops_run_prexor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
688} 688}
689 689
690static struct dma_async_tx_descriptor * 690static struct dma_async_tx_descriptor *
691ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx) 691ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx,
692 unsigned long pending)
692{ 693{
693 int disks = sh->disks; 694 int disks = sh->disks;
694 int pd_idx = sh->pd_idx, i; 695 int pd_idx = sh->pd_idx, i;
@@ -696,7 +697,7 @@ ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
696 /* check if prexor is active which means only process blocks 697 /* check if prexor is active which means only process blocks
697 * that are part of a read-modify-write (Wantprexor) 698 * that are part of a read-modify-write (Wantprexor)
698 */ 699 */
699 int prexor = test_bit(STRIPE_OP_PREXOR, &sh->ops.pending); 700 int prexor = test_bit(STRIPE_OP_PREXOR, &pending);
700 701
701 pr_debug("%s: stripe %llu\n", __FUNCTION__, 702 pr_debug("%s: stripe %llu\n", __FUNCTION__,
702 (unsigned long long)sh->sector); 703 (unsigned long long)sh->sector);
@@ -773,7 +774,8 @@ static void ops_complete_write(void *stripe_head_ref)
773} 774}
774 775
775static void 776static void
776ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx) 777ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx,
778 unsigned long pending)
777{ 779{
778 /* kernel stack size limits the total number of disks */ 780 /* kernel stack size limits the total number of disks */
779 int disks = sh->disks; 781 int disks = sh->disks;
@@ -781,7 +783,7 @@ ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
781 783
782 int count = 0, pd_idx = sh->pd_idx, i; 784 int count = 0, pd_idx = sh->pd_idx, i;
783 struct page *xor_dest; 785 struct page *xor_dest;
784 int prexor = test_bit(STRIPE_OP_PREXOR, &sh->ops.pending); 786 int prexor = test_bit(STRIPE_OP_PREXOR, &pending);
785 unsigned long flags; 787 unsigned long flags;
786 dma_async_tx_callback callback; 788 dma_async_tx_callback callback;
787 789
@@ -808,7 +810,7 @@ ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
808 } 810 }
809 811
810 /* check whether this postxor is part of a write */ 812 /* check whether this postxor is part of a write */
811 callback = test_bit(STRIPE_OP_BIODRAIN, &sh->ops.pending) ? 813 callback = test_bit(STRIPE_OP_BIODRAIN, &pending) ?
812 ops_complete_write : ops_complete_postxor; 814 ops_complete_write : ops_complete_postxor;
813 815
814 /* 1/ if we prexor'd then the dest is reused as a source 816 /* 1/ if we prexor'd then the dest is reused as a source
@@ -896,12 +898,12 @@ static void raid5_run_ops(struct stripe_head *sh, unsigned long pending)
896 tx = ops_run_prexor(sh, tx); 898 tx = ops_run_prexor(sh, tx);
897 899
898 if (test_bit(STRIPE_OP_BIODRAIN, &pending)) { 900 if (test_bit(STRIPE_OP_BIODRAIN, &pending)) {
899 tx = ops_run_biodrain(sh, tx); 901 tx = ops_run_biodrain(sh, tx, pending);
900 overlap_clear++; 902 overlap_clear++;
901 } 903 }
902 904
903 if (test_bit(STRIPE_OP_POSTXOR, &pending)) 905 if (test_bit(STRIPE_OP_POSTXOR, &pending))
904 ops_run_postxor(sh, tx); 906 ops_run_postxor(sh, tx, pending);
905 907
906 if (test_bit(STRIPE_OP_CHECK, &pending)) 908 if (test_bit(STRIPE_OP_CHECK, &pending))
907 ops_run_check(sh); 909 ops_run_check(sh);