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Diffstat (limited to 'fs/nfs/pnfs.c')
-rw-r--r--fs/nfs/pnfs.c24
1 files changed, 19 insertions, 5 deletions
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 212cbc22c59d..59ed68bf79fa 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -371,6 +371,14 @@ pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo,
memcpy(&lo->plh_stateid, &new->stateid, sizeof(new->stateid));
}
+/* lget is set to 1 if called from inside send_layoutget call chain */
+static bool
+pnfs_layoutgets_blocked(struct pnfs_layout_hdr *lo, int lget)
+{
+ return (list_empty(&lo->plh_segs) &&
+ (atomic_read(&lo->plh_outstanding) > lget));
+}
+
int
pnfs_choose_layoutget_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo,
struct nfs4_state *open_state)
@@ -379,7 +387,9 @@ pnfs_choose_layoutget_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo,
dprintk("--> %s\n", __func__);
spin_lock(&lo->plh_inode->i_lock);
- if (list_empty(&lo->plh_segs)) {
+ if (pnfs_layoutgets_blocked(lo, 1)) {
+ status = -EAGAIN;
+ } else if (list_empty(&lo->plh_segs)) {
int seq;
do {
@@ -414,10 +424,8 @@ send_layoutget(struct pnfs_layout_hdr *lo,
BUG_ON(ctx == NULL);
lgp = kzalloc(sizeof(*lgp), GFP_KERNEL);
- if (lgp == NULL) {
- put_layout_hdr(lo->plh_inode);
+ if (lgp == NULL)
return NULL;
- }
lgp->args.minlength = NFS4_MAX_UINT64;
lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
lgp->args.range.iomode = iomode;
@@ -613,10 +621,16 @@ pnfs_update_layout(struct inode *ino,
if (test_bit(lo_fail_bit(iomode), &nfsi->layout->plh_flags))
goto out_unlock;
- get_layout_hdr_locked(lo); /* Matched in nfs4_layoutget_release */
+ if (pnfs_layoutgets_blocked(lo, 0))
+ goto out_unlock;
+ atomic_inc(&lo->plh_outstanding);
+
+ get_layout_hdr_locked(lo);
spin_unlock(&ino->i_lock);
lseg = send_layoutget(lo, ctx, iomode);
+ atomic_dec(&lo->plh_outstanding);
+ put_layout_hdr(ino);
out:
dprintk("%s end, state 0x%lx lseg %p\n", __func__,
nfsi->layout->plh_flags, lseg);