xfs: introduce the xfs_iext_cursor abstraction
Add a new xfs_iext_cursor structure to hide the direct extent map
index manipulations. In addition to the existing lookup/get/insert/
remove and update routines new primitives to get the first and last
extent cursor, as well as moving up and down by one extent are
provided. Also new are convenience to increment/decrement the
cursor and retreive the new extent, as well as to peek into the
previous/next extent without updating the cursor and last but not
least a macro to iterate over all extents in a fork.
[darrick: rename for_each_iext to for_each_xfs_iext]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index da0abc8..ad48e2f 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -390,7 +390,7 @@ xfs_iomap_prealloc_size(
struct xfs_inode *ip,
loff_t offset,
loff_t count,
- xfs_extnum_t idx)
+ struct xfs_iext_cursor *icur)
{
struct xfs_mount *mp = ip->i_mount;
struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
@@ -415,7 +415,7 @@ xfs_iomap_prealloc_size(
*/
if ((mp->m_flags & XFS_MOUNT_DFLT_IOSIZE) ||
XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, mp->m_dalign) ||
- !xfs_iext_get_extent(ifp, idx - 1, &prev) ||
+ !xfs_iext_peek_prev_extent(ifp, icur, &prev) ||
prev.br_startoff + prev.br_blockcount < offset_fsb)
return mp->m_writeio_blocks;
@@ -533,7 +533,7 @@ xfs_file_iomap_begin_delay(
xfs_fileoff_t end_fsb;
int error = 0, eof = 0;
struct xfs_bmbt_irec got;
- xfs_extnum_t idx;
+ struct xfs_iext_cursor icur;
xfs_fsblock_t prealloc_blocks = 0;
ASSERT(!XFS_IS_REALTIME_INODE(ip));
@@ -558,7 +558,7 @@ xfs_file_iomap_begin_delay(
goto out_unlock;
}
- eof = !xfs_iext_lookup_extent(ip, ifp, offset_fsb, &idx, &got);
+ eof = !xfs_iext_lookup_extent(ip, ifp, offset_fsb, &icur, &got);
if (!eof && got.br_startoff <= offset_fsb) {
if (xfs_is_reflink_inode(ip)) {
bool shared;
@@ -592,7 +592,8 @@ xfs_file_iomap_begin_delay(
end_fsb = min(XFS_B_TO_FSB(mp, offset + count), maxbytes_fsb);
if (eof) {
- prealloc_blocks = xfs_iomap_prealloc_size(ip, offset, count, idx);
+ prealloc_blocks = xfs_iomap_prealloc_size(ip, offset, count,
+ &icur);
if (prealloc_blocks) {
xfs_extlen_t align;
xfs_off_t end_offset;
@@ -614,7 +615,8 @@ xfs_file_iomap_begin_delay(
retry:
error = xfs_bmapi_reserve_delalloc(ip, XFS_DATA_FORK, offset_fsb,
- end_fsb - offset_fsb, prealloc_blocks, &got, &idx, eof);
+ end_fsb - offset_fsb, prealloc_blocks, &got, &icur,
+ eof);
switch (error) {
case 0:
break;