NFSv4.1 do not send LAYOUTRETURN on emtpy plh_segs list

mark_matching_lsegs_invalid() resets the mds_threshold counters and can
dereference the layout hdr on an initial empty plh_segs list. It returns 0 both
in the case of an initial empty list and in a non-emtpy list that was cleared
by calls to mark_lseg_invalid.

Don't send a LAYOUTRETURN if the list was initially empty.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Andy Adamson 2012-06-20 15:03:34 -04:00 committed by Trond Myklebust
parent 366d50521c
commit 293b3b065c

View File

@ -651,7 +651,14 @@ send_layoutget(struct pnfs_layout_hdr *lo,
return NULL;
}
/* Initiates a LAYOUTRETURN(FILE) */
/*
* Initiates a LAYOUTRETURN(FILE), and removes the pnfs_layout_hdr
* when the layout segment list is empty.
*
* Note that a pnfs_layout_hdr can exist with an empty layout segment
* list when LAYOUTGET has failed, or when LAYOUTGET succeeded, but the
* deviceid is marked invalid.
*/
int
_pnfs_return_layout(struct inode *ino)
{
@ -660,7 +667,7 @@ _pnfs_return_layout(struct inode *ino)
LIST_HEAD(tmp_list);
struct nfs4_layoutreturn *lrp;
nfs4_stateid stateid;
int status = 0;
int status = 0, empty;
dprintk("NFS: %s for inode %lu\n", __func__, ino->i_ino);
@ -668,13 +675,21 @@ _pnfs_return_layout(struct inode *ino)
lo = nfsi->layout;
if (!lo || pnfs_test_layout_returned(lo)) {
spin_unlock(&ino->i_lock);
dprintk("%s: no layout to return\n", __func__);
return status;
dprintk("NFS: %s no layout to return\n", __func__);
goto out;
}
stateid = nfsi->layout->plh_stateid;
/* Reference matched in nfs4_layoutreturn_release */
get_layout_hdr(lo);
empty = list_empty(&lo->plh_segs);
mark_matching_lsegs_invalid(lo, &tmp_list, NULL);
/* Don't send a LAYOUTRETURN if list was initially empty */
if (empty) {
spin_unlock(&ino->i_lock);
put_layout_hdr(lo);
dprintk("NFS: %s no layout segments to return\n", __func__);
goto out;
}
lo->plh_block_lgets++;
pnfs_mark_layout_returned(lo);
spin_unlock(&ino->i_lock);