Hi Trond, I'm having some trouble with xfstests generic/464 after applying this patch. Here is the oops I'm getting, I'm able to reproduce it fairly easily against all NFS versions: [ 41.182015] BUG: unable to handle kernel NULL pointer dereference at 0000000000000048 [ 41.182051] #PF error: [normal kernel read fault] [ 41.182071] PGD 0 P4D 0 [ 41.182086] Oops: 0000 [#1] PREEMPT SMP PTI [ 41.182104] CPU: 1 PID: 14515 Comm: kworker/1:6 Not tainted 5.1.0-rc3-ANNA+ #5292 [ 41.182131] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 41.182174] Workqueue: nfsiod rpc_async_release [sunrpc] [ 41.182209] RIP: 0010:__put_nfs_open_context+0xd/0x110 [nfs] [ 41.182227] Code: f8 ba a8 00 00 00 be c0 0c 00 00 e8 5d c0 58 f7 48 89 c3 48 85 c0 74 c5 e9 15 ff ff ff 0f 1f 44 00 00 41 56 41 55 41 54 55 53 <48> 8b 47 48 48 8b 68 30 4c 8b 60 68 f0 ff 0f 0f 88 14 53 01 00 74 [ 41.182267] RSP: 0018:ffffae5f04b6be30 EFLAGS: 00010246 [ 41.182279] RAX: 0000000000000000 RBX: ffffa22aae71a680 RCX: 0000000000000000 [ 41.182295] RDX: ffffffffb9205dc8 RSI: 0000000000000000 RDI: 0000000000000000 [ 41.182311] RBP: 0000000000000801 R08: ffffa22aa5ca0000 R09: ffffa22aba267800 [ 41.182327] R10: 0000000000000000 R11: 0000000000000000 R12: ffffce5effd1c200 [ 41.182351] R13: 0000000000000000 R14: ffffa22aad2aa6c0 R15: 0ffffce5effd1c20 [ 41.182378] FS: 0000000000000000(0000) GS:ffffa22abcb00000(0000) knlGS:0000000000000000 [ 41.182411] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 41.182435] CR2: 0000000000000048 CR3: 00000000af972005 CR4: 0000000000160ee0 [ 41.182468] Call Trace: [ 41.182495] nfs_commitdata_release+0x15/0x30 [nfs] [ 41.182536] rpc_free_task+0x39/0x70 [sunrpc] [ 41.182571] rpc_async_release+0x29/0x40 [sunrpc] [ 41.182594] process_one_work+0x1eb/0x410 [ 41.182611] worker_thread+0x2d/0x3d0 [ 41.182621] ? process_one_work+0x410/0x410 [ 41.182632] kthread+0x112/0x130 [ 41.182641] ? kthread_park+0x80/0x80 [ 41.182652] ret_from_fork+0x35/0x40 [ 41.182662] Modules linked in: nfsv3 nfs fscache rpcrdma ib_isert iscsi_target_mod ib_iser libiscsi scsi_transport_iscsi ib_srpt target_core_mod ib_srp scsi_transport_srp ib_ipoib rdma_ucm ib_uverbs ib_umad rdma_cm cfg80211 ib_cm iw_cm rfkill 8021q mrp ib_core crct10dif_pclmul crc32_pclmul joydev mousedev crc32c_intel ghash_clmulni_intel aesni_intel input_leds led_class psmouse aes_x86_64 evdev crypto_simd cryptd glue_helper mac_hid intel_agp intel_gtt i2c_piix4 pcspkr nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables x_tables ata_generic pata_acpi serio_raw atkbd libps2 ata_piix libata scsi_mod floppy i8042 serio xfs virtio_balloon virtio_gpu drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm virtio_net net_failover failover agpgart virtio_pci virtio_blk virtio_ring virtio [ 41.182827] CR2: 0000000000000048 [ 41.182836] ---[ end trace 19c8b9d2801d26ce ]--- Let me know if you need any more information! Anna On Fri, 2019-03-29 at 17:59 -0400, Trond Myklebust wrote: > The lock context already references and tracks the open context, so > take the opportunity to save some space in struct nfs_page. > > Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> > --- > fs/nfs/pagelist.c | 7 +------ > include/linux/nfs_page.h | 3 +-- > 2 files changed, 2 insertions(+), 8 deletions(-) > > diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c > index ce6440b79328..5d5ac5df93e2 100644 > --- a/fs/nfs/pagelist.c > +++ b/fs/nfs/pagelist.c > @@ -325,7 +325,6 @@ __nfs_create_request(struct nfs_lock_context *l_ctx, > struct page *page, > req->wb_offset = offset; > req->wb_pgbase = pgbase; > req->wb_bytes = count; > - req->wb_context = get_nfs_open_context(ctx); > kref_init(&req->wb_kref); > req->wb_nio = 0; > return req; > @@ -414,8 +413,8 @@ void nfs_unlock_and_release_request(struct nfs_page *req) > static void nfs_clear_request(struct nfs_page *req) > { > struct page *page = req->wb_page; > - struct nfs_open_context *ctx = req->wb_context; > struct nfs_lock_context *l_ctx = req->wb_lock_context; > + struct nfs_open_context *ctx = l_ctx->open_context; > > if (page != NULL) { > put_page(page); > @@ -430,10 +429,6 @@ static void nfs_clear_request(struct nfs_page *req) > nfs_put_lock_context(l_ctx); > req->wb_lock_context = NULL; > } > - if (ctx != NULL) { > - put_nfs_open_context(ctx); > - req->wb_context = NULL; > - } > } > > /** > diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h > index 1ea13e94feb7..0bbd587fac6a 100644 > --- a/include/linux/nfs_page.h > +++ b/include/linux/nfs_page.h > @@ -42,7 +42,6 @@ struct nfs_inode; > struct nfs_page { > struct list_head wb_list; /* Defines state of page: */ > struct page *wb_page; /* page to read in/write out > */ > - struct nfs_open_context *wb_context; /* File state context info */ > struct nfs_lock_context *wb_lock_context; /* lock context info > */ > pgoff_t wb_index; /* Offset >> PAGE_SHIFT */ > unsigned int wb_offset, /* Offset & ~PAGE_MASK */ > @@ -203,7 +202,7 @@ loff_t req_offset(struct nfs_page *req) > static inline struct nfs_open_context * > nfs_req_openctx(struct nfs_page *req) > { > - return req->wb_context; > + return req->wb_lock_context->open_context; > } > > #endif /* _LINUX_NFS_PAGE_H */