From: Trond Myklebust trond.myklebust@hammerspace.com
[ Upstream commit 51069e4aef6257b0454057359faed0ab0c9af083 ]
If we're asked to recover open state while a delegation return is outstanding, then the state manager thread cannot use a cached open, so if the server returns a delegation, we can end up deadlocked behind the pending delegreturn. To avoid this problem, let's just ask the server not to give us a delegation unless we're explicitly reclaiming one.
Fixes: be36e185bd26 ("NFSv4: nfs4_open_recover_helper() must set share access") Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/nfs/nfs4proc.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-)
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 15550d673e61..ee46ab09e330 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -2126,18 +2126,18 @@ static struct nfs4_opendata *nfs4_open_recoverdata_alloc(struct nfs_open_context }
static int nfs4_open_recover_helper(struct nfs4_opendata *opendata, - fmode_t fmode) + fmode_t fmode) { struct nfs4_state *newstate; + struct nfs_server *server = NFS_SB(opendata->dentry->d_sb); + int openflags = opendata->o_arg.open_flags; int ret;
if (!nfs4_mode_match_open_stateid(opendata->state, fmode)) return 0; - opendata->o_arg.open_flags = 0; opendata->o_arg.fmode = fmode; - opendata->o_arg.share_access = nfs4_map_atomic_open_share( - NFS_SB(opendata->dentry->d_sb), - fmode, 0); + opendata->o_arg.share_access = + nfs4_map_atomic_open_share(server, fmode, openflags); memset(&opendata->o_res, 0, sizeof(opendata->o_res)); memset(&opendata->c_res, 0, sizeof(opendata->c_res)); nfs4_init_opendata_res(opendata); @@ -2713,10 +2713,15 @@ static int _nfs4_open_expired(struct nfs_open_context *ctx, struct nfs4_state *s struct nfs4_opendata *opendata; int ret;
- opendata = nfs4_open_recoverdata_alloc(ctx, state, - NFS4_OPEN_CLAIM_FH); + opendata = nfs4_open_recoverdata_alloc(ctx, state, NFS4_OPEN_CLAIM_FH); if (IS_ERR(opendata)) return PTR_ERR(opendata); + /* + * We're not recovering a delegation, so ask for no delegation. + * Otherwise the recovery thread could deadlock with an outstanding + * delegation return. + */ + opendata->o_arg.open_flags = O_DIRECT; ret = nfs4_open_recover(opendata, state); if (ret == -ESTALE) d_drop(ctx->dentry);