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| author | Fred Isaman <iisaman@netapp.com> | 2011-02-03 21:28:52 +0300 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2011-03-11 23:38:40 +0300 |
| commit | f49f9baac8f63de9cbc17a0a84e04060496e8e76 (patch) | |
| tree | e3e544247ec5e85c47915d34737f278772d15c73 /fs/nfs/callback_proc.c | |
| parent | 9f52c2525e09854ed6aa4cbd83915a56226d86c1 (diff) | |
| download | linux-f49f9baac8f63de9cbc17a0a84e04060496e8e76.tar.xz | |
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.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c index 89587573fe50..2f41dccea18e 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; } |