[LU-12945] Avoid sending PageSlab pages through tcp stack

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.14.0
• Severity: 3
• Assignee: Shaun Tancheff
• Reporter: Shaun Tancheff

Description

Oct 26 12:58:25 oss kernel: BUG: Bad page state in process socknal_sd03_00 pfn:b0641
Oct 26 12:58:25 oss kernel: page:ffffeea482c19040 count:0 mapcount:-1 mapping: (null) index:0x0
Oct 26 12:58:25 oss kernel: page flags: 0x1fffff00008000(tail)
Oct 26 12:58:25 oss kernel: page dumped because: nonzero mapcount
Oct 26 12:58:25 oss kernel: Modules linked in: osp(OE) ofd(OE) lfsck(OE) ost(OE) mgc(OE) osd_zfs(OE) lquota(OE) fid(OE) fld(OE) ksocklnd(OE) ptlrpc(OE) obdclass(OE) lnet(OE) libcfs(OE) fuse zfs(POE) snd_hda_codec_generic zunicode(POE) zlua(POE) ppdev zcommon(POE) znvpair(POE) zavl(POE) snd_hda_intel icp(POE) iosf_mbi crc32_pclmul snd_hda_codec spl(OE) snd_hda_core snd_hwdep ghash_clmulni_intel snd_seq snd_seq_device aesni_intel snd_pcm lrw gf128mul joydev glue_helper snd_timer parport_pc ablk_helper snd virtio_balloon cryptd pcspkr parport sg soundcore i2c_piix4 ip_tables xfs libcrc32c sd_mod sr_mod crc_t10dif cdrom crct10dif_generic ata_generic pata_acpi virtio_scsi virtio_net virtio_console qxl drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm ata_piix drm crct10dif_pclmul libata virtio_pci crct10dif_common
Oct 26 12:58:25 oss kernel: virtio_ring crc32c_intel serio_raw floppy virtio drm_panel_orientation_quirks dm_mirror dm_region_hash dm_log dm_mod
Oct 26 12:58:25 oss kernel: CPU: 6 PID: 4165 Comm: socknal_sd03_00 Kdump: loaded Tainted: P OE ------------ 3.10.0-957.27.3.ldiskfs.el7.x86_64 #1

When running with upstream linux debug [CONFIG_DEBUG_VM] kernel (v5.0-3279-ga10674bf2406) has added a test for PageSlab() on the memory passed to tcp_sendpages and blocks sending.

Oct 30 23:47:01 oss kernel: WARNING: CPU: 2 PID: 3642 at net/ipv4/tcp.c:966 do_tcp_sendpages+0xb56/0xcb0

Avoid sending PageSlab through the tcp stack