[PATCH 37/42] xfs: factor out MRU hit case in xfs_filestream_select_ag

Dave Chinner
2023-01-18T22:45:37Z

Because it now stands out like a sore thumb. Factoring out this case
starts the process of simplifying xfs_filestream_select_ag() again.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/xfs/xfs_filestream.c | 133 +++++++++++++++++++++++++---------------
1 file changed, 83 insertions(+), 50 deletions(-)

diff --git a/fs/xfs/xfs_filestream.c b/fs/xfs/xfs_filestream.c
index 95e28aae35ab..147296a1079e 100644
--- a/fs/xfs/xfs_filestream.c
+++ b/fs/xfs/xfs_filestream.c
@@ -259,10 +259,85 @@ xfs_filestream_get_parent(
return dir ? XFS_I(dir) : NULL;
}

+/*
+ * Lookup the mru cache for an existing association. If one exists and we can
+ * use it, return with the agno and blen indicating that the allocation will
+ * proceed with that association.
+ *
+ * If we have no association, or we cannot use the current one and have to
+ * destroy it, return with blen = 0 and agno pointing at the next agno to try.
+ */
+int
+xfs_filestream_select_ag_mru(
+ struct xfs_bmalloca *ap,
+ struct xfs_alloc_arg *args,
+ struct xfs_inode *pip,
+ xfs_agnumber_t *agno,
+ xfs_extlen_t *blen)
+{
+ struct xfs_mount *mp = ap->ip->i_mount;
+ struct xfs_perag *pag;
+ struct xfs_mru_cache_elem *mru;
+ int error;
+
+ mru = xfs_mru_cache_lookup(mp->m_filestream, pip->i_ino);
+ if (!mru)
+ goto out_default_agno;
+
+ *agno = container_of(mru, struct xfs_fstrm_item, mru)->ag;
+ xfs_mru_cache_done(mp->m_filestream);
+
+ trace_xfs_filestream_lookup(mp, ap->ip->i_ino, *agno);
+
+ ap->blkno = XFS_AGB_TO_FSB(args->mp, *agno, 0);
+ xfs_bmap_adjacent(ap);
+
+ pag = xfs_perag_grab(mp, *agno);
+ if (!pag)
+ goto out_default_agno;
+
+ error = xfs_bmap_longest_free_extent(pag, args->tp, blen);
+ xfs_perag_rele(pag);
+ if (error) {
+ if (error != -EAGAIN)
+ return error;
+ *blen = 0;
+ }
+
+ /*
+ * We are done if there's still enough contiguous free space to succeed.
+ */
+ if (*blen >= args->maxlen)
+ return 0;
+
+ /* Changing parent AG association now, so remove the existing one. */
+ mru = xfs_mru_cache_remove(mp->m_filestream, pip->i_ino);
+ if (mru) {
+ struct xfs_fstrm_item *item =
+ container_of(mru, struct xfs_fstrm_item, mru);
+ *agno = (item->ag + 1) % mp->m_sb.sb_agcount;
+ xfs_fstrm_free_func(mp, mru);
+ return 0;
+ }
+
+out_default_agno:
+ if (xfs_is_inode32(mp)) {
+ xfs_agnumber_t rotorstep = xfs_rotorstep;
+ *agno = (mp->m_agfrotor / rotorstep) %
+ mp->m_sb.sb_agcount;
+ mp->m_agfrotor = (mp->m_agfrotor + 1) %
+ (mp->m_sb.sb_agcount * rotorstep);
+ return 0;
+ }
+ *agno = XFS_INO_TO_AGNO(mp, pip->i_ino);
+ return 0;
+
+}
+
/*
* Search for an allocation group with a single extent large enough for
- * the request. If one isn't found, then the largest available free extent is
- * returned as the best length possible.
+ * the request. If one isn't found, then adjust the minimum allocation
+ * size to the largest space found.
*/
int
xfs_filestream_select_ag(
@@ -271,12 +346,10 @@ xfs_filestream_select_ag(
xfs_extlen_t *blen)
{
struct xfs_mount *mp = ap->ip->i_mount;
- struct xfs_perag *pag;
struct xfs_inode *pip = NULL;
- xfs_agnumber_t agno = NULLAGNUMBER;
- struct xfs_mru_cache_elem *mru;
+ xfs_agnumber_t agno;
int flags = 0;
- int error = 0;
+ int error;

args->total = ap->total;
*blen = 0;
@@ -287,48 +360,10 @@ xfs_filestream_select_ag(
goto out_select;
}

- mru = xfs_mru_cache_lookup(mp->m_filestream, pip->i_ino);
- if (mru) {
- agno = container_of(mru, struct xfs_fstrm_item, mru)->ag;
- xfs_mru_cache_done(mp->m_filestream);
- mru = NULL;
-
- trace_xfs_filestream_lookup(mp, ap->ip->i_ino, agno);
- xfs_irele(pip);
-
- ap->blkno = XFS_AGB_TO_FSB(args->mp, agno, 0);
- xfs_bmap_adjacent(ap);
-
- pag = xfs_perag_grab(mp, agno);
- if (pag) {
- error = xfs_bmap_longest_free_extent(pag, args->tp, blen);
- xfs_perag_rele(pag);
- if (error) {
- if (error != -EAGAIN)
- goto out_error;
- *blen = 0;
- }
- }
- if (*blen >= args->maxlen)
- goto out_select;
- } else if (xfs_is_inode32(mp)) {
- xfs_agnumber_t rotorstep = xfs_rotorstep;
- agno = (mp->m_agfrotor / rotorstep) %
- mp->m_sb.sb_agcount;
- mp->m_agfrotor = (mp->m_agfrotor + 1) %
- (mp->m_sb.sb_agcount * rotorstep);
- } else {
- agno = XFS_INO_TO_AGNO(mp, pip->i_ino);
- }
+ error = xfs_filestream_select_ag_mru(ap, args, pip, &agno, blen);
+ if (error || *blen >= args->maxlen)
+ goto out_rele;

- /* Changing parent AG association now, so remove the existing one. */
- mru = xfs_mru_cache_remove(mp->m_filestream, pip->i_ino);
- if (mru) {
- struct xfs_fstrm_item *item =
- container_of(mru, struct xfs_fstrm_item, mru);
- agno = (item->ag + 1) % mp->m_sb.sb_agcount;
- xfs_fstrm_free_func(mp, mru);
- }
ap->blkno = XFS_AGB_TO_FSB(args->mp, agno, 0);
xfs_bmap_adjacent(ap);

@@ -347,8 +382,6 @@ xfs_filestream_select_ag(

*blen = ap->length;
error = xfs_filestream_pick_ag(pip, &agno, flags, blen);
- if (error)
- goto out_error;
if (agno == NULLAGNUMBER) {
agno = 0;
*blen = 0;
@@ -356,7 +389,7 @@ xfs_filestream_select_ag(

out_select:
ap->blkno = XFS_AGB_TO_FSB(mp, agno, 0);
-out_error:
+out_rele:
xfs_irele(pip);
return error;

--
2.39.0