xfs: maintain a sequence count for inode fork manipulations

Add a simple 32-bit unsigned integer as the sequence count for
modifications to the extent list in the inode fork.  This will be
used to optimize away extent list lookups in the writeback code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
This commit is contained in:
Christoph Hellwig 2018-07-17 16:51:51 -07:00 committed by Darrick J. Wong
parent 9e037cb797
commit 745b3f76d1
2 changed files with 7 additions and 0 deletions

View file

@ -624,6 +624,8 @@ xfs_iext_insert(
struct xfs_iext_leaf *new = NULL;
int nr_entries, i;
ifp->if_seq++;
if (ifp->if_height == 0)
xfs_iext_alloc_root(ifp, cur);
else if (ifp->if_height == 1)
@ -864,6 +866,8 @@ xfs_iext_remove(
ASSERT(ifp->if_u1.if_root != NULL);
ASSERT(xfs_iext_valid(ifp, cur));
ifp->if_seq++;
nr_entries = xfs_iext_leaf_nr_entries(ifp, leaf, cur->pos) - 1;
for (i = cur->pos; i < nr_entries; i++)
leaf->recs[i] = leaf->recs[i + 1];
@ -970,6 +974,8 @@ xfs_iext_update_extent(
{
struct xfs_ifork *ifp = xfs_iext_state_to_fork(ip, state);
ifp->if_seq++;
if (cur->pos == 0) {
struct xfs_bmbt_irec old;

View file

@ -14,6 +14,7 @@ struct xfs_dinode;
*/
struct xfs_ifork {
int if_bytes; /* bytes in if_u1 */
unsigned int if_seq; /* cow fork mod counter */
struct xfs_btree_block *if_broot; /* file's incore btree root */
short if_broot_bytes; /* bytes allocated for root */
unsigned char if_flags; /* per-fork flags */