[PATCH 2/3] xfs: hoist AGI repair context to a heap object

Darrick J. Wong
2024-03-27T02:06:25Z

Save ~460 bytes of stack space by moving all the repair context to a
heap object. We're going to add even more context data in the next
patch, which is why we really need to do this now.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/scrub/agheader_repair.c | 105 ++++++++++++++++++++++++----------------
1 file changed, 63 insertions(+), 42 deletions(-)

diff --git a/fs/xfs/scrub/agheader_repair.c b/fs/xfs/scrub/agheader_repair.c
index 427054b65b238..d210bd7d5eb13 100644
--- a/fs/xfs/scrub/agheader_repair.c
+++ b/fs/xfs/scrub/agheader_repair.c
@@ -796,15 +796,29 @@ enum {
XREP_AGI_MAX
};

+struct xrep_agi {
+ struct xfs_scrub *sc;
+
+ /* AGI buffer, tracked separately */
+ struct xfs_buf *agi_bp;
+
+ /* context for finding btree roots */
+ struct xrep_find_ag_btree fab[XREP_AGI_MAX];
+
+ /* old AGI contents in case we have to revert */
+ struct xfs_agi old_agi;
+};
+
/*
* Given the inode btree roots described by *fab, find the roots, check them
* for sanity, and pass the root data back out via *fab.
*/
STATIC int
xrep_agi_find_btrees(
- struct xfs_scrub *sc,
- struct xrep_find_ag_btree *fab)
+ struct xrep_agi *ragi)
{
+ struct xfs_scrub *sc = ragi->sc;
+ struct xrep_find_ag_btree *fab = ragi->fab;
struct xfs_buf *agf_bp;
struct xfs_mount *mp = sc->mp;
int error;
@@ -837,10 +851,11 @@ xrep_agi_find_btrees(
*/
STATIC void
xrep_agi_init_header(
- struct xfs_scrub *sc,
- struct xfs_buf *agi_bp,
- struct xfs_agi *old_agi)
+ struct xrep_agi *ragi)
{
+ struct xfs_scrub *sc = ragi->sc;
+ struct xfs_buf *agi_bp = ragi->agi_bp;
+ struct xfs_agi *old_agi = &ragi->old_agi;
struct xfs_agi *agi = agi_bp->b_addr;
struct xfs_perag *pag = sc->sa.pag;
struct xfs_mount *mp = sc->mp;
@@ -868,10 +883,12 @@ xrep_agi_init_header(
/* Set btree root information in an AGI. */
STATIC void
xrep_agi_set_roots(
- struct xfs_scrub *sc,
- struct xfs_agi *agi,
- struct xrep_find_ag_btree *fab)
+ struct xrep_agi *ragi)
{
+ struct xfs_scrub *sc = ragi->sc;
+ struct xfs_agi *agi = ragi->agi_bp->b_addr;
+ struct xrep_find_ag_btree *fab = ragi->fab;
+
agi->agi_root = cpu_to_be32(fab[XREP_AGI_INOBT].root);
agi->agi_level = cpu_to_be32(fab[XREP_AGI_INOBT].height);

@@ -884,9 +901,10 @@ xrep_agi_set_roots(
/* Update the AGI counters. */
STATIC int
xrep_agi_calc_from_btrees(
- struct xfs_scrub *sc,
- struct xfs_buf *agi_bp)
+ struct xrep_agi *ragi)
{
+ struct xfs_scrub *sc = ragi->sc;
+ struct xfs_buf *agi_bp = ragi->agi_bp;
struct xfs_btree_cur *cur;
struct xfs_agi *agi = agi_bp->b_addr;
struct xfs_mount *mp = sc->mp;
@@ -931,9 +949,10 @@ xrep_agi_calc_from_btrees(
/* Trigger reinitialization of the in-core data. */
STATIC int
xrep_agi_commit_new(
- struct xfs_scrub *sc,
- struct xfs_buf *agi_bp)
+ struct xrep_agi *ragi)
{
+ struct xfs_scrub *sc = ragi->sc;
+ struct xfs_buf *agi_bp = ragi->agi_bp;
struct xfs_perag *pag;
struct xfs_agi *agi = agi_bp->b_addr;

@@ -956,33 +975,36 @@ xrep_agi_commit_new(
/* Repair the AGI. */
int
xrep_agi(
- struct xfs_scrub *sc)
+ struct xfs_scrub *sc)
{
- struct xrep_find_ag_btree fab[XREP_AGI_MAX] = {
- [XREP_AGI_INOBT] = {
- .rmap_owner = XFS_RMAP_OWN_INOBT,
- .buf_ops = &xfs_inobt_buf_ops,
- .maxlevels = M_IGEO(sc->mp)->inobt_maxlevels,
- },
- [XREP_AGI_FINOBT] = {
- .rmap_owner = XFS_RMAP_OWN_INOBT,
- .buf_ops = &xfs_finobt_buf_ops,
- .maxlevels = M_IGEO(sc->mp)->inobt_maxlevels,
- },
- [XREP_AGI_END] = {
- .buf_ops = NULL
- },
- };
- struct xfs_agi old_agi;
- struct xfs_mount *mp = sc->mp;
- struct xfs_buf *agi_bp;
- struct xfs_agi *agi;
- int error;
+ struct xrep_agi *ragi;
+ struct xfs_mount *mp = sc->mp;
+ int error;

/* We require the rmapbt to rebuild anything. */
if (!xfs_has_rmapbt(mp))
return -EOPNOTSUPP;

+ sc->buf = kzalloc(sizeof(struct xrep_agi), XCHK_GFP_FLAGS);
+ if (!sc->buf)
+ return -ENOMEM;
+ ragi = sc->buf;
+ ragi->sc = sc;
+
+ ragi->fab[XREP_AGI_INOBT] = (struct xrep_find_ag_btree){
+ .rmap_owner = XFS_RMAP_OWN_INOBT,
+ .buf_ops = &xfs_inobt_buf_ops,
+ .maxlevels = M_IGEO(sc->mp)->inobt_maxlevels,
+ };
+ ragi->fab[XREP_AGI_FINOBT] = (struct xrep_find_ag_btree){
+ .rmap_owner = XFS_RMAP_OWN_INOBT,
+ .buf_ops = &xfs_finobt_buf_ops,
+ .maxlevels = M_IGEO(sc->mp)->inobt_maxlevels,
+ };
+ ragi->fab[XREP_AGI_END] = (struct xrep_find_ag_btree){
+ .buf_ops = NULL,
+ };
+
/*
* Make sure we have the AGI buffer, as scrub might have decided it
* was corrupt after xfs_ialloc_read_agi failed with -EFSCORRUPTED.
@@ -990,14 +1012,13 @@ xrep_agi(
error = xfs_trans_read_buf(mp, sc->tp, mp->m_ddev_targp,
XFS_AG_DADDR(mp, sc->sa.pag->pag_agno,
XFS_AGI_DADDR(mp)),
- XFS_FSS_TO_BB(mp, 1), 0, &agi_bp, NULL);
+ XFS_FSS_TO_BB(mp, 1), 0, &ragi->agi_bp, NULL);
if (error)
return error;
- agi_bp->b_ops = &xfs_agi_buf_ops;
- agi = agi_bp->b_addr;
+ ragi->agi_bp->b_ops = &xfs_agi_buf_ops;

/* Find the AGI btree roots. */
- error = xrep_agi_find_btrees(sc, fab);
+ error = xrep_agi_find_btrees(ragi);
if (error)
return error;

@@ -1006,18 +1027,18 @@ xrep_agi(
return error;

/* Start rewriting the header and implant the btrees we found. */
- xrep_agi_init_header(sc, agi_bp, &old_agi);
- xrep_agi_set_roots(sc, agi, fab);
- error = xrep_agi_calc_from_btrees(sc, agi_bp);
+ xrep_agi_init_header(ragi);
+ xrep_agi_set_roots(ragi);
+ error = xrep_agi_calc_from_btrees(ragi);
if (error)
goto out_revert;

/* Reinitialize in-core state. */
- return xrep_agi_commit_new(sc, agi_bp);
+ return xrep_agi_commit_new(ragi);

out_revert:
/* Mark the incore AGI state stale and revert the AGI. */
clear_bit(XFS_AGSTATE_AGI_INIT, &sc->sa.pag->pag_opstate);
- memcpy(agi, &old_agi, sizeof(old_agi));
+ memcpy(ragi->agi_bp->b_addr, &ragi->old_agi, sizeof(struct xfs_agi));
return error;
}