NFSv4.1: Always clear the NFS_INO_LAYOUTCOMMIT in layoutreturn

Note that clearing NFS_INO_LAYOUTCOMMIT is tricky, since it requires
you to also clear the NFS_LSEG_LAYOUTCOMMIT bits from the layout
segments.
The only two sites that need to do this are the ones that call
pnfs_return_layout() without first doing a layout commit.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Benny Halevy <bhalevy@tonian.com>
Cc: stable@vger.kernel.org

2 files changed, 27 insertions, 9 deletions

diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
index 49eeb044c109..4fb234d3aefb 100644
--- a/fs/nfs/nfs4filelayout.c
+++ b/fs/nfs/nfs4filelayout.c
@@ -129,7 +129,6 @@ static void filelayout_fenceme(struct inode *inode, struct pnfs_layout_hdr *lo)
 {
         if (!test_and_clear_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
                 return;
-        clear_bit(NFS_INO_LAYOUTCOMMIT, &NFS_I(inode)->flags);
         pnfs_return_layout(inode);
 }
 
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 3d900916fd41..5044142c1216 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -417,6 +417,16 @@ should_free_lseg(struct pnfs_layout_range *lseg_range,
                lo_seg_intersecting(lseg_range, recall_range);
 }
 
+static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
+                struct list_head *tmp_list)
+{
+        if (!atomic_dec_and_test(&lseg->pls_refcount))
+                return false;
+        pnfs_layout_remove_lseg(lseg->pls_layout, lseg);
+        list_add(&lseg->pls_list, tmp_list);
+        return true;
+}
+
 /* Returns 1 if lseg is removed from list, 0 otherwise */
 static int mark_lseg_invalid(struct pnfs_layout_segment *lseg,
                              struct list_head *tmp_list)
@@ -430,11 +440,8 @@ static int mark_lseg_invalid(struct pnfs_layout_segment *lseg,
                  */
                 dprintk("%s: lseg %p ref %d\n", __func__, lseg,
                         atomic_read(&lseg->pls_refcount));
-                if (atomic_dec_and_test(&lseg->pls_refcount)) {
-                        pnfs_layout_remove_lseg(lseg->pls_layout, lseg);
-                        list_add(&lseg->pls_list, tmp_list);
+                if (pnfs_lseg_dec_and_remove_zero(lseg, tmp_list))
                         rv = 1;
-                }
         }
         return rv;
 }
@@ -777,6 +784,21 @@ send_layoutget(struct pnfs_layout_hdr *lo,
         return lseg;
 }
 
+static void pnfs_clear_layoutcommit(struct inode *inode,
+                struct list_head *head)
+{
+        struct nfs_inode *nfsi = NFS_I(inode);
+        struct pnfs_layout_segment *lseg, *tmp;
+
+        if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
+                return;
+        list_for_each_entry_safe(lseg, tmp, &nfsi->layout->plh_segs, pls_list) {
+                if (!test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
+                        continue;
+                pnfs_lseg_dec_and_remove_zero(lseg, head);
+        }
+}
+
 /*
  * Initiates a LAYOUTRETURN(FILE), and removes the pnfs_layout_hdr
  * when the layout segment list is empty.
@@ -808,6 +830,7 @@ _pnfs_return_layout(struct inode *ino)
         /* Reference matched in nfs4_layoutreturn_release */
         pnfs_get_layout_hdr(lo);
         empty = list_empty(&lo->plh_segs);
+        pnfs_clear_layoutcommit(ino, &tmp_list);
         pnfs_mark_matching_lsegs_invalid(lo, &tmp_list, NULL);
         /* Don't send a LAYOUTRETURN if list was initially empty */
         if (empty) {
@@ -820,8 +843,6 @@ _pnfs_return_layout(struct inode *ino)
         spin_unlock(&ino->i_lock);
         pnfs_free_lseg_list(&tmp_list);
 
-        WARN_ON(test_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags));
-
         lrp = kzalloc(sizeof(*lrp), GFP_KERNEL);
         if (unlikely(lrp == NULL)) {
                 status = -ENOMEM;
@@ -1458,7 +1479,6 @@ static void pnfs_ld_handle_write_error(struct nfs_write_data *data)
         dprintk("pnfs write error = %d\n", hdr->pnfs_error);
         if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
             PNFS_LAYOUTRET_ON_ERROR) {
-                clear_bit(NFS_INO_LAYOUTCOMMIT, &NFS_I(hdr->inode)->flags);
                 pnfs_return_layout(hdr->inode);
         }
         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
@@ -1613,7 +1633,6 @@ static void pnfs_ld_handle_read_error(struct nfs_read_data *data)
         dprintk("pnfs read error = %d\n", hdr->pnfs_error);
         if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
             PNFS_LAYOUTRET_ON_ERROR) {
-                clear_bit(NFS_INO_LAYOUTCOMMIT, &NFS_I(hdr->inode)->flags);
                 pnfs_return_layout(hdr->inode);
         }
         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))