On Sat, 2019-10-05 at 14:07 +0000, Trond Myklebust wrote: > On Sat, 2019-10-05 at 09:51 +0800, zhangxiaoxu (A) wrote: > > ping. > > > > On 2019/9/26 14:29, ZhangXiaoxu wrote: > > > When xfstests testing, there are some WARNING as below: > > > > > > WARNING: CPU: 0 PID: 6235 at fs/nfs/inode.c:122 > > > nfs_clear_inode+0x9c/0xd8 > > > Modules linked in: > > > CPU: 0 PID: 6235 Comm: umount.nfs > > > Hardware name: linux,dummy-virt (DT) > > > pstate: 60000005 (nZCv daif -PAN -UAO) > > > pc : nfs_clear_inode+0x9c/0xd8 > > > lr : nfs_evict_inode+0x60/0x78 > > > sp : fffffc000f68fc00 > > > x29: fffffc000f68fc00 x28: fffffe00c53155c0 > > > x27: fffffe00c5315000 x26: fffffc0009a63748 > > > x25: fffffc000f68fd18 x24: fffffc000bfaaf40 > > > x23: fffffc000936d3c0 x22: fffffe00c4ff5e20 > > > x21: fffffc000bfaaf40 x20: fffffe00c4ff5d10 > > > x19: fffffc000c056000 x18: 000000000000003c > > > x17: 0000000000000000 x16: 0000000000000000 > > > x15: 0000000000000040 x14: 0000000000000228 > > > x13: fffffc000c3a2000 x12: 0000000000000045 > > > x11: 0000000000000000 x10: 0000000000000000 > > > x9 : 0000000000000000 x8 : 0000000000000000 > > > x7 : 0000000000000000 x6 : fffffc00084b027c > > > x5 : fffffc0009a64000 x4 : fffffe00c0e77400 > > > x3 : fffffc000c0563a8 x2 : fffffffffffffffb > > > x1 : 000000000000764e x0 : 0000000000000001 > > > Call trace: > > > nfs_clear_inode+0x9c/0xd8 > > > nfs_evict_inode+0x60/0x78 > > > evict+0x108/0x380 > > > dispose_list+0x70/0xa0 > > > evict_inodes+0x194/0x210 > > > generic_shutdown_super+0xb0/0x220 > > > nfs_kill_super+0x40/0x88 > > > deactivate_locked_super+0xb4/0x120 > > > deactivate_super+0x144/0x160 > > > cleanup_mnt+0x98/0x148 > > > __cleanup_mnt+0x38/0x50 > > > task_work_run+0x114/0x160 > > > do_notify_resume+0x2f8/0x308 > > > work_pending+0x8/0x14 > > > > > > The nrequest should be increased/decreased only if PG_INODE_REF > > > flag > > > was setted. > > > > > > But in the nfs_inode_remove_request function, it maybe decrease > > > when > > > no PG_INODE_REF flag, this maybe lead nrequests count error. > > > > > > Reported-by: Hulk Robot <hulkci@xxxxxxxxxx> > > > Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@xxxxxxxxxx> > > > --- > > > fs/nfs/write.c | 5 +++-- > > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > > > diff --git a/fs/nfs/write.c b/fs/nfs/write.c > > > index 85ca495..52cab65 100644 > > > --- a/fs/nfs/write.c > > > +++ b/fs/nfs/write.c > > > @@ -786,7 +786,6 @@ static void nfs_inode_remove_request(struct > > > nfs_page *req) > > > struct nfs_inode *nfsi = NFS_I(inode); > > > struct nfs_page *head; > > > > > > - atomic_long_dec(&nfsi->nrequests); > > > if (nfs_page_group_sync_on_bit(req, PG_REMOVE)) { > > > head = req->wb_head; > > > > > > @@ -799,8 +798,10 @@ static void nfs_inode_remove_request(struct > > > nfs_page *req) > > > spin_unlock(&mapping->private_lock); > > > } > > > > > > - if (test_and_clear_bit(PG_INODE_REF, &req->wb_flags)) > > > + if (test_and_clear_bit(PG_INODE_REF, &req->wb_flags)) { > > > nfs_release_request(req); > > > + atomic_long_dec(&nfsi->nrequests); > > > + } > > > } > > > > > > static void > > > > > Hmm... What about nfs_page_group_init()? That also bumps nfsi- > > nrequests. Ah... Never mind, that's just copying the PG_INODE_REF flag to the new subrequest. However nfs_lock_and_join_requests() looks like it does need to change to something like the following: /* Postpone destruction of this request */ - if (test_and_clear_bit(PG_REMOVE, &head->wb_flags)) { - set_bit(PG_INODE_REF, &head->wb_flags); + if (test_and_clear_bit(PG_REMOVE, &head->wb_flags) && + !test_and_set_bit(PG_INODE_REF, &head->wb_flags)) { kref_get(&head->wb_kref); atomic_long_inc(&NFS_I(inode)->nrequests); } Do you agree? -- Trond Myklebust Linux NFS client maintainer, Hammerspace trond.myklebust@xxxxxxxxxxxxxxx