[PATCH 44/50] xfs: factor out MRU hit case in xfs_filestream_select_ag

Dave Chinner
2022-06-11T01:27:37Z

Because it now stands out like a sore thumb and factoring out this
special case will simplify xfs_filestream_select_ag() again.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/xfs/xfs_filestream.c | 127 ++++++++++++++++++++++++----------------
1 file changed, 78 insertions(+), 49 deletions(-)

diff --git a/fs/xfs/xfs_filestream.c b/fs/xfs/xfs_filestream.c
index d251f78ffc95..fcc30e8ebb90 100644
--- a/fs/xfs/xfs_filestream.c
+++ b/fs/xfs/xfs_filestream.c
@@ -260,73 +260,106 @@ xfs_filestream_get_parent(
}

/*
- * Search for an allocation group with a single extent large enough for
- * the request. If one isn't found, then adjust the minimum allocation
- * size to the largest space found.
+ * 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(
+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_inode *pip = NULL;
- xfs_agnumber_t agno = NULLAGNUMBER;
struct xfs_mru_cache_elem *mru;
- int flags = 0;
int error;

- args->total = ap->total;
*blen = 0;
+ mru = xfs_mru_cache_lookup(mp->m_filestream, pip->i_ino);
+ if (!mru)
+ goto out_default_agno;

- pip = xfs_filestream_get_parent(ap->ip);
- if (!pip) {
- agno = 0;
- goto out_select;
+ *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;
}

- mru = xfs_mru_cache_lookup(mp->m_filestream, pip->i_ino);
+ 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) {
- 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);
-
- 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)) {
+ 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) %
+ *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);
+ return 0;
}
+ *agno = XFS_INO_TO_AGNO(mp, pip->i_ino);
+ 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;
+}
+
+/*
+ * Search for an allocation group with a single extent large enough for
+ * the request. If one isn't found, then adjust the minimum allocation
+ * size to the largest space found.
+ */
+int
+xfs_filestream_select_ag(
+ struct xfs_bmalloca *ap,
+ struct xfs_alloc_arg *args,
+ xfs_extlen_t *blen)
+{
+ struct xfs_mount *mp = ap->ip->i_mount;
+ struct xfs_inode *pip = NULL;
+ xfs_agnumber_t agno;
+ int flags = 0;
+ int error;
+
+ args->total = ap->total;
+ pip = xfs_filestream_get_parent(ap->ip);
+ if (!pip) {
+ agno = 0;
+ goto out_select;
}
+
+ error = xfs_filestream_select_ag_mru(ap, args, pip, &agno, blen);
+ if (error || *blen >= args->maxlen)
+ goto out_rele;
+
ap->blkno = XFS_AGB_TO_FSB(args->mp, agno, 0);
xfs_bmap_adjacent(ap);

@@ -337,16 +370,12 @@ 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;
}

-out_error:
- if (mru)
- xfs_fstrm_free_func(mp, mru);
+out_rele:
xfs_irele(pip);
out_select:
if (!error)
--
2.35.1