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Commit 411ae722 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

pNFS: Wait for stale layoutget calls to complete in pnfs_update_layout() 



If the old layout was recalled, and we returned NFS4ERR_NOMATCHINGLAYOUT
then we need to wait for all outstanding layoutget calls to complete
before we can send a new one.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent 056f9ad6

fs/nfs/pnfs.c

+31 −5
Original line number Diff line number Diff line
@@ -1740,6 +1740,17 @@ static bool pnfs_prepare_to_retry_layoutget(struct pnfs_layout_hdr *lo) 
				   TASK_UNINTERRUPTIBLE);

}



static void nfs_layoutget_begin(struct pnfs_layout_hdr *lo)

{

	atomic_inc(&lo->plh_outstanding);

}



static void nfs_layoutget_end(struct pnfs_layout_hdr *lo)

{

	if (atomic_dec_and_test(&lo->plh_outstanding))

		wake_up_var(&lo->plh_outstanding);

}



static void pnfs_clear_first_layoutget(struct pnfs_layout_hdr *lo)

{

	unsigned long *bitlock = &lo->plh_flags;
@@ -1839,6 +1850,21 @@ pnfs_update_layout(struct inode *ino, 
		goto out_unlock;

	}



	/*

	 * If the layout segment list is empty, but there are outstanding

	 * layoutget calls, then they might be subject to a layoutrecall.

	 */

	if (list_empty(&lo->plh_segs) &&

	    atomic_read(&lo->plh_outstanding) != 0) {

		spin_unlock(&ino->i_lock);

		if (wait_var_event_killable(&lo->plh_outstanding,

					atomic_read(&lo->plh_outstanding) == 0

					|| !list_empty(&lo->plh_segs)))

			goto out_put_layout_hdr;

		pnfs_put_layout_hdr(lo);

		goto lookup_again;

	}



	lseg = pnfs_find_lseg(lo, &arg, strict_iomode);

	if (lseg) {

		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
@@ -1912,7 +1938,7 @@ pnfs_update_layout(struct inode *ino, 
				PNFS_UPDATE_LAYOUT_BLOCKED);

		goto out_unlock;

	}

	atomic_inc(&lo->plh_outstanding);

	nfs_layoutget_begin(lo);

	spin_unlock(&ino->i_lock);



	_add_to_server_list(lo, server);
@@ -1929,14 +1955,14 @@ pnfs_update_layout(struct inode *ino, 
	if (!lgp) {

		trace_pnfs_update_layout(ino, pos, count, iomode, lo, NULL,

					 PNFS_UPDATE_LAYOUT_NOMEM);

		atomic_dec(&lo->plh_outstanding);

		nfs_layoutget_end(lo);

		goto out_put_layout_hdr;

	}



	lseg = nfs4_proc_layoutget(lgp, &timeout);

	trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,

				 PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET);

	atomic_dec(&lo->plh_outstanding);

	nfs_layoutget_end(lo);

	if (IS_ERR(lseg)) {

		switch(PTR_ERR(lseg)) {

		case -EBUSY:
@@ -2031,7 +2057,7 @@ _pnfs_grab_empty_layout(struct inode *ino, struct nfs_open_context *ctx) 
		goto out_unlock;

	if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET, &lo->plh_flags))

		goto out_unlock;

	atomic_inc(&lo->plh_outstanding);

	nfs_layoutget_begin(lo);

	spin_unlock(&ino->i_lock);

	_add_to_server_list(lo, NFS_SERVER(ino));

	return lo;
@@ -2172,8 +2198,8 @@ void nfs4_lgopen_release(struct nfs4_layoutget *lgp) 
		struct inode *inode = lgp->args.inode;

		if (inode) {

			struct pnfs_layout_hdr *lo = NFS_I(inode)->layout;

			atomic_dec(&lo->plh_outstanding);

			pnfs_clear_first_layoutget(lo);

			nfs_layoutget_end(lo);

		}

		pnfs_layoutget_free(lgp);

	}