From 49a4bda22e186c4d0eb07f4a36b5b1a378f9398d Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Thu, 1 May 2014 06:28:46 -0400 Subject: [PATCH] nfs4: queue free_lock_state job submission to nfsiod We got a report of the following warning in Fedora: BUG: sleeping function called from invalid context at mm/slub.c:969 in_atomic(): 1, irqs_disabled(): 0, pid: 533, name: bash 3 locks held by bash/533: #0: (&sp->so_delegreturn_mutex){+.+...}, at: [] nfs4_proc_lock+0x262/0x910 [nfsv4] #1: (&nfsi->rwsem){.+.+.+}, at: [] nfs4_proc_lock+0x26a/0x910 [nfsv4] #2: (&sb->s_type->i_lock_key#23){+.+...}, at: [] flock_lock_file_wait+0x8c/0x3a0 CPU: 0 PID: 533 Comm: bash Not tainted 3.15.0-0.rc1.git1.1.fc21.x86_64 #1 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 0000000000000000 00000000d664ff3c ffff880078b69a70 ffffffff817e82e0 0000000000000000 ffff880078b69a98 ffffffff810cf1a4 0000000000000050 0000000000000050 ffff88007cc01a00 ffff880078b69ad8 ffffffff8121449e Call Trace: [] dump_stack+0x4d/0x66 [] __might_sleep+0x184/0x240 [] kmem_cache_alloc_trace+0x4e/0x330 [] ? nfs4_release_lockowner+0x74/0x110 [nfsv4] [] nfs4_release_lockowner+0x74/0x110 [nfsv4] [] nfs4_put_lock_state+0x90/0xb0 [nfsv4] [] nfs4_fl_release_lock+0x15/0x20 [nfsv4] [] locks_free_lock+0x45/0x90 [] flock_lock_file_wait+0x11c/0x3a0 [] ? nfs4_proc_lock+0x26a/0x910 [nfsv4] [] do_vfs_lock+0x1e/0x30 [nfsv4] [] nfs4_proc_lock+0x279/0x910 [nfsv4] [] ? local_clock+0x16/0x30 [] ? lock_release_holdtime.part.28+0xf/0x200 [] do_unlk+0x8c/0xc0 [nfs] [] nfs_flock+0xa5/0xf0 [nfs] [] locks_remove_file+0xb6/0x1e0 [] ? kfree+0xd8/0x2d0 [] __fput+0xd3/0x210 [] ____fput+0xe/0x10 [] task_work_run+0xcd/0xf0 [] do_notify_resume+0x61/0x90 [] int_signal+0x12/0x17 The problem is that NFSv4 is trying to do an allocation from fl_release_private (in order to send a RELEASE_LOCKOWNER call). That function can be called while holding the inode->i_lock, and it's currently set up to do __GFP_WAIT allocations. v4.1 code has a similar problem. This patch adds a work_struct to the nfs4_lock_state and has the code queue the free_lock_state operation to nfsiod. Reported-by: Josh Stone Signed-off-by: Jeff Layton Signed-off-by: Trond Myklebust --- fs/nfs/nfs4_fs.h | 13 +++++++------ fs/nfs/nfs4state.c | 24 ++++++++++++++++++------ 2 files changed, 25 insertions(+), 12 deletions(-) diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index 19f567c39670..5e2a8afc72cb 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -130,15 +130,16 @@ enum { */ struct nfs4_lock_state { - struct list_head ls_locks; /* Other lock stateids */ - struct nfs4_state * ls_state; /* Pointer to open state */ + struct list_head ls_locks; /* Other lock stateids */ + struct nfs4_state * ls_state; /* Pointer to open state */ #define NFS_LOCK_INITIALIZED 0 #define NFS_LOCK_LOST 1 - unsigned long ls_flags; + unsigned long ls_flags; struct nfs_seqid_counter ls_seqid; - nfs4_stateid ls_stateid; - atomic_t ls_count; - fl_owner_t ls_owner; + nfs4_stateid ls_stateid; + atomic_t ls_count; + fl_owner_t ls_owner; + struct work_struct ls_release; }; /* bits for nfs4_state->flags */ diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index 544040835482..a770c8e469a7 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -799,6 +799,18 @@ __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner) return NULL; } +static void +free_lock_state_work(struct work_struct *work) +{ + struct nfs4_lock_state *lsp = container_of(work, + struct nfs4_lock_state, ls_release); + struct nfs4_state *state = lsp->ls_state; + struct nfs_server *server = state->owner->so_server; + struct nfs_client *clp = server->nfs_client; + + clp->cl_mvops->free_lock_state(server, lsp); +} + /* * Return a compatible lock_state. If no initialized lock_state structure * exists, return an uninitialized one. @@ -820,6 +832,7 @@ static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, f if (lsp->ls_seqid.owner_id < 0) goto out_free; INIT_LIST_HEAD(&lsp->ls_locks); + INIT_WORK(&lsp->ls_release, free_lock_state_work); return lsp; out_free: kfree(lsp); @@ -883,13 +896,12 @@ void nfs4_put_lock_state(struct nfs4_lock_state *lsp) if (list_empty(&state->lock_states)) clear_bit(LK_STATE_IN_USE, &state->flags); spin_unlock(&state->state_lock); - server = state->owner->so_server; - if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) { - struct nfs_client *clp = server->nfs_client; - - clp->cl_mvops->free_lock_state(server, lsp); - } else + if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) + queue_work(nfsiod_workqueue, &lsp->ls_release); + else { + server = state->owner->so_server; nfs4_free_lock_state(server, lsp); + } } static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src) -- 2.30.2