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: [<ffffffffa033da62>] nfs4_proc_lock+0x262/0x910 [nfsv4]
#1: (&nfsi->rwsem){.+.+.+}, at: [<ffffffffa033da6a>] nfs4_proc_lock+0x26a/0x910 [nfsv4]
#2: (&sb->s_type->i_lock_key#23){+.+...}, at: [<ffffffff812998dc>] 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:
[<ffffffff817e82e0>] dump_stack+0x4d/0x66
[<ffffffff810cf1a4>] __might_sleep+0x184/0x240
[<ffffffff8121449e>] kmem_cache_alloc_trace+0x4e/0x330
[<ffffffffa0331124>] ? nfs4_release_lockowner+0x74/0x110 [nfsv4]
[<ffffffffa0331124>] nfs4_release_lockowner+0x74/0x110 [nfsv4]
[<ffffffffa0352340>] nfs4_put_lock_state+0x90/0xb0 [nfsv4]
[<ffffffffa0352375>] nfs4_fl_release_lock+0x15/0x20 [nfsv4]
[<ffffffff81297515>] locks_free_lock+0x45/0x90
[<ffffffff8129996c>] flock_lock_file_wait+0x11c/0x3a0
[<ffffffffa033da6a>] ? nfs4_proc_lock+0x26a/0x910 [nfsv4]
[<ffffffffa033301e>] do_vfs_lock+0x1e/0x30 [nfsv4]
[<ffffffffa033da79>] nfs4_proc_lock+0x279/0x910 [nfsv4]
[<ffffffff810dbb26>] ? local_clock+0x16/0x30
[<ffffffff810f5a3f>] ? lock_release_holdtime.part.28+0xf/0x200
[<ffffffffa02f820c>] do_unlk+0x8c/0xc0 [nfs]
[<ffffffffa02f85c5>] nfs_flock+0xa5/0xf0 [nfs]
[<ffffffff8129a6f6>] locks_remove_file+0xb6/0x1e0
[<ffffffff812159d8>] ? kfree+0xd8/0x2d0
[<ffffffff8123bc63>] __fput+0xd3/0x210
[<ffffffff8123bdee>] ____fput+0xe/0x10
[<ffffffff810bfb6d>] task_work_run+0xcd/0xf0
[<ffffffff81019cd1>] do_notify_resume+0x61/0x90
[<ffffffff817fbea2>] 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 <jistone@xxxxxxxxxx>
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxxxxxxx>
---
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 3888dd0b43a1..75aadf8c0429 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 f43e5016343e..1919483bcf17 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)
--
1.9.0
--
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