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authorFred Isaman <iisaman@netapp.com>2011-02-03 18:28:52 +0000
committerTrond Myklebust <Trond.Myklebust@netapp.com>2011-03-11 15:38:40 -0500
commitf49f9baac8f63de9cbc17a0a84e04060496e8e76 (patch)
treee3e544247ec5e85c47915d34737f278772d15c73 /fs/nfs/callback_proc.c
parent9f52c2525e09854ed6aa4cbd83915a56226d86c1 (diff)
pnfs: fix pnfs lock inversion of i_lock and cl_lock
The pnfs code was using throughout the lock order i_lock, cl_lock. This conflicts with the nfs delegation code. Rework the pnfs code to avoid taking both locks simultaneously. Currently the code takes the double lock to add/remove the layout to a nfs_client list, while atomically checking that the list of lsegs is empty. To avoid this, we rely on existing serializations. When a layout is initialized with lseg count equal zero, LAYOUTGET's openstateid serialization is in effect, making it safe to assume it stays zero unless we change it. And once a layout's lseg count drops to zero, it is set as DESTROYED and so will stay at zero. Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/callback_proc.c')
-rw-r--r--fs/nfs/callback_proc.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index 89587573fe5..2f41dccea18 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -188,10 +188,10 @@ static u32 initiate_bulk_draining(struct nfs_client *clp,
rv = NFS4ERR_DELAY;
list_del_init(&lo->plh_bulk_recall);
spin_unlock(&ino->i_lock);
+ pnfs_free_lseg_list(&free_me_list);
put_layout_hdr(lo);
iput(ino);
}
- pnfs_free_lseg_list(&free_me_list);
return rv;
}