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| author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2013-02-07 10:54:07 -0500 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2013-02-11 15:33:13 -0500 |
| commit | 65b62a29f719e937b5be1df472287f4c61e53ac6 (patch) | |
| tree | ea6b552a08883d92cfedb891044fa9697cbc5619 /fs/nfs/delegation.c | |
| parent | 37380e4264dbda9753e470a30d4322097aab7152 (diff) | |
| download | lwn-65b62a29f719e937b5be1df472287f4c61e53ac6.tar.gz lwn-65b62a29f719e937b5be1df472287f4c61e53ac6.zip | |
NFSv4: Ensure delegation recall and byte range lock removal don't conflict
Add a mutex to the struct nfs4_state_owner to ensure that delegation
recall doesn't conflict with byte range lock removal.
Note that we nest the new mutex _outside_ the state manager reclaim
protection (nfsi->rwsem) in order to avoid deadlocks.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/delegation.c')
| -rw-r--r-- | fs/nfs/delegation.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index 2542cdaa1116..6390a4b5fee7 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -71,8 +71,10 @@ static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_ int status = 0; if (inode->i_flock == NULL) - goto out; + return 0; + if (inode->i_flock == NULL) + goto out; /* Protect inode->i_flock using the file locks lock */ lock_flocks(); for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) { @@ -113,12 +115,15 @@ again: get_nfs_open_context(ctx); spin_unlock(&inode->i_lock); sp = state->owner; + /* Block nfs4_proc_unlck */ + mutex_lock(&sp->so_delegreturn_mutex); seq = raw_seqcount_begin(&sp->so_reclaim_seqcount); err = nfs4_open_delegation_recall(ctx, state, stateid); if (!err) err = nfs_delegation_claim_locks(ctx, state); if (!err && read_seqcount_retry(&sp->so_reclaim_seqcount, seq)) err = -EAGAIN; + mutex_unlock(&sp->so_delegreturn_mutex); put_nfs_open_context(ctx); if (err != 0) return err; |