NFSv4.1/pnfs: Fix a close/delegreturn hang when return-on-close is set
The helper pnfs_roc() has already verified that we have no delegations,
and no further open files, hence no outstanding I/O and it has marked
all the return-on-close lsegs as being invalid.
Furthermore, it sets the NFS_LAYOUT_RETURN bit, thus serialising the
close/delegreturn with all future layoutget calls on this inode.
The checks in pnfs_roc_drain() for valid layout segments are therefore
redundant: those cannot exist until another layoutget completes.
The other check for whether or not NFS_LAYOUT_RETURN is set, actually
causes a hang, since we already know that we hold that flag.
To fix, we therefore strip out all the functionality in pnfs_roc_drain()
except the retrieval of the barrier state, and then rename the function
accordingly.
Reported-by: Christoph Hellwig <hch@infradead.org>
Fixes: 5c4a79fb2b1c ("Don't prevent layoutgets when doing return-on-close")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 6151f39..6aabbb6 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1141,25 +1141,14 @@
spin_unlock(&ino->i_lock);
}
-bool pnfs_roc_drain(struct inode *ino, u32 *barrier, struct rpc_task *task)
+void pnfs_roc_get_barrier(struct inode *ino, u32 *barrier)
{
struct nfs_inode *nfsi = NFS_I(ino);
struct pnfs_layout_hdr *lo;
- struct pnfs_layout_segment *lseg;
nfs4_stateid stateid;
u32 current_seqid;
- bool layoutreturn = false;
spin_lock(&ino->i_lock);
- list_for_each_entry(lseg, &nfsi->layout->plh_segs, pls_list) {
- if (!test_bit(NFS_LSEG_ROC, &lseg->pls_flags))
- continue;
- if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags))
- continue;
- rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
- spin_unlock(&ino->i_lock);
- return true;
- }
lo = nfsi->layout;
current_seqid = be32_to_cpu(lo->plh_stateid.seqid);
@@ -1168,18 +1157,7 @@
*/
*barrier = current_seqid + atomic_read(&lo->plh_outstanding);
stateid = lo->plh_stateid;
- if (test_and_clear_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE,
- &lo->plh_flags))
- layoutreturn = pnfs_prepare_layoutreturn(lo);
- if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
- rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
-
spin_unlock(&ino->i_lock);
- if (layoutreturn) {
- pnfs_send_layoutreturn(lo, stateid, IOMODE_ANY, false);
- return true;
- }
- return false;
}
/*
