knfsd: nfsd4: don't delegate files that have had conflicts
One more incremental delegation policy improvement: don't give out a
delegation on a file if conflicting access has previously required that a
delegation be revoked on that file. (In practice we'll forget about the
conflict when the struct nfs4_file is removed on close, so this is of limited
use for now, though it should at least solve a temporary problem with
self-conflicts on write opens from the same client.)
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 4624988..e4a4c87 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -195,6 +195,8 @@
struct nfs4_callback *cb = &stp->st_stateowner->so_client->cl_callback;
dprintk("NFSD alloc_init_deleg\n");
+ if (fp->fi_had_conflict)
+ return NULL;
if (num_delegations > max_delegations)
return NULL;
dp = kmem_cache_alloc(deleg_slab, GFP_KERNEL);
@@ -1002,6 +1004,7 @@
list_add(&fp->fi_hash, &file_hashtbl[hashval]);
fp->fi_inode = igrab(ino);
fp->fi_id = current_fileid++;
+ fp->fi_had_conflict = false;
return fp;
}
return NULL;
@@ -1328,6 +1331,7 @@
{
struct nfs4_delegation *dp = __dp;
+ dp->dl_file->fi_had_conflict = true;
nfsd4_cb_recall(dp);
return 0;
}