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authorDan Williams <dan.j.williams@intel.com>2007-11-14 16:59:35 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-11-14 18:45:39 -0800
commit6c55be8b962f1bdc592d579e81fc27b11ea53dfc (patch)
tree3413cc2c8e26afdbc498cbdbd96bc2fa9733b2a6 /drivers/md
parent5b23dbe8173c212d6a326e35347b038705603d39 (diff)
downloadop-kernel-dev-6c55be8b962f1bdc592d579e81fc27b11ea53dfc.zip
op-kernel-dev-6c55be8b962f1bdc592d579e81fc27b11ea53dfc.tar.gz
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/md')
-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 1cfc984..a5aad8c 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)
}
static struct dma_async_tx_descriptor *
-ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
+ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx,
+ unsigned long pending)
{
int disks = sh->disks;
int pd_idx = sh->pd_idx, i;
@@ -696,7 +697,7 @@ ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
/* check if prexor is active which means only process blocks
* that are part of a read-modify-write (Wantprexor)
*/
- int prexor = test_bit(STRIPE_OP_PREXOR, &sh->ops.pending);
+ int prexor = test_bit(STRIPE_OP_PREXOR, &pending);
pr_debug("%s: stripe %llu\n", __FUNCTION__,
(unsigned long long)sh->sector);
@@ -773,7 +774,8 @@ static void ops_complete_write(void *stripe_head_ref)
}
static void
-ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
+ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx,
+ unsigned long pending)
{
/* kernel stack size limits the total number of disks */
int disks = sh->disks;
@@ -781,7 +783,7 @@ ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
int count = 0, pd_idx = sh->pd_idx, i;
struct page *xor_dest;
- int prexor = test_bit(STRIPE_OP_PREXOR, &sh->ops.pending);
+ int prexor = test_bit(STRIPE_OP_PREXOR, &pending);
unsigned long flags;
dma_async_tx_callback callback;
@@ -808,7 +810,7 @@ ops_run_postxor(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
}
/* check whether this postxor is part of a write */
- callback = test_bit(STRIPE_OP_BIODRAIN, &sh->ops.pending) ?
+ callback = test_bit(STRIPE_OP_BIODRAIN, &pending) ?
ops_complete_write : ops_complete_postxor;
/* 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)
tx = ops_run_prexor(sh, tx);
if (test_bit(STRIPE_OP_BIODRAIN, &pending)) {
- tx = ops_run_biodrain(sh, tx);
+ tx = ops_run_biodrain(sh, tx, pending);
overlap_clear++;
}
if (test_bit(STRIPE_OP_POSTXOR, &pending))
- ops_run_postxor(sh, tx);
+ ops_run_postxor(sh, tx, pending);
if (test_bit(STRIPE_OP_CHECK, &pending))
ops_run_check(sh);
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