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Date: Tue, 2 Apr 2013 15:10:20 -0700
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org,
Trond Myklebust <Trond.Myklebust@...app.com>,
Benny Halevy <bhalevy@...ian.com>
Subject: [ 038/124] NFSv4.1: Fix a race in pNFS layoutcommit
3.8-stable review patch. If anyone has any objections, please let me know.
------------------
From: Trond Myklebust <Trond.Myklebust@...app.com>
commit a073dbff359f4741013ae4b8395f5364c5e00b48 upstream.
We need to clear the NFS_LSEG_LAYOUTCOMMIT bits atomically with the
NFS_INO_LAYOUTCOMMIT bit, otherwise we may end up with situations
where the two are out of sync.
The first half of the problem is to ensure that pnfs_layoutcommit_inode
clears the NFS_LSEG_LAYOUTCOMMIT bit through pnfs_list_write_lseg.
We still need to keep the reference to those segments until the RPC call
is finished, so in order to make it clear _where_ those references come
from, we add a helper pnfs_list_write_lseg_done() that cleans up after
pnfs_list_write_lseg.
Signed-off-by: Trond Myklebust <Trond.Myklebust@...app.com>
Acked-by: Benny Halevy <bhalevy@...ian.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
fs/nfs/nfs4proc.c | 14 --------------
fs/nfs/pnfs.c | 19 ++++++++++++++++++-
2 files changed, 18 insertions(+), 15 deletions(-)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -6366,22 +6366,8 @@ nfs4_layoutcommit_done(struct rpc_task *
static void nfs4_layoutcommit_release(void *calldata)
{
struct nfs4_layoutcommit_data *data = calldata;
- struct pnfs_layout_segment *lseg, *tmp;
- unsigned long *bitlock = &NFS_I(data->args.inode)->flags;
pnfs_cleanup_layoutcommit(data);
- /* Matched by references in pnfs_set_layoutcommit */
- list_for_each_entry_safe(lseg, tmp, &data->lseg_list, pls_lc_list) {
- list_del_init(&lseg->pls_lc_list);
- if (test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT,
- &lseg->pls_flags))
- pnfs_put_lseg(lseg);
- }
-
- clear_bit_unlock(NFS_INO_LAYOUTCOMMITTING, bitlock);
- smp_mb__after_clear_bit();
- wake_up_bit(bitlock, NFS_INO_LAYOUTCOMMITTING);
-
put_rpccred(data->cred);
kfree(data);
}
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1747,11 +1747,27 @@ static void pnfs_list_write_lseg(struct
list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list) {
if (lseg->pls_range.iomode == IOMODE_RW &&
- test_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
+ test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
list_add(&lseg->pls_lc_list, listp);
}
}
+static void pnfs_list_write_lseg_done(struct inode *inode, struct list_head *listp)
+{
+ struct pnfs_layout_segment *lseg, *tmp;
+ unsigned long *bitlock = &NFS_I(inode)->flags;
+
+ /* Matched by references in pnfs_set_layoutcommit */
+ list_for_each_entry_safe(lseg, tmp, listp, pls_lc_list) {
+ list_del_init(&lseg->pls_lc_list);
+ pnfs_put_lseg(lseg);
+ }
+
+ clear_bit_unlock(NFS_INO_LAYOUTCOMMITTING, bitlock);
+ smp_mb__after_clear_bit();
+ wake_up_bit(bitlock, NFS_INO_LAYOUTCOMMITTING);
+}
+
void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg)
{
pnfs_layout_io_set_failed(lseg->pls_layout, lseg->pls_range.iomode);
@@ -1796,6 +1812,7 @@ void pnfs_cleanup_layoutcommit(struct nf
if (nfss->pnfs_curr_ld->cleanup_layoutcommit)
nfss->pnfs_curr_ld->cleanup_layoutcommit(data);
+ pnfs_list_write_lseg_done(data->args.inode, &data->lseg_list);
}
/*
--
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