[PATCH v2 2/3] NFSv4.1: Always clear the NFS_INO_LAYOUTCOMMIT in layoutreturn

Trond Myklebust
2013-03-21T14:13:06Z

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
---
fs/nfs/nfs4filelayout.c | 1 -
fs/nfs/pnfs.c | 35 +++++++++++++++++++++++++++--------
2 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
index 49eeb04..4fb234d 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 c6bbb53..b9d0682 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 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 (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;
+ 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))
--
1.8.1.4