[PATCH 08/13] xfs: updating i_next_unlinked doesn't need to return old value

Dave Chinner
2020-08-12T09:26:03Z

From: Dave Chinner <dchinner@redhat.com>

We already know what the next inode in the unlinked list is supposed
to be from the in-memory list, so we do not need to look it up first
from the current inode to be able to update in memory list
pointers...

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/xfs/xfs_inode.c | 63 +++++++++++-----------------------------------
1 file changed, 14 insertions(+), 49 deletions(-)

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index bacd5ae9f5a7..4dde1970f7cd 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1998,13 +1998,11 @@ xfs_iunlink_update_inode(
struct xfs_trans *tp,
struct xfs_inode *ip,
xfs_agnumber_t agno,
- xfs_agino_t next_agino,
- xfs_agino_t *old_next_agino)
+ xfs_agino_t next_agino)
{
struct xfs_mount *mp = tp->t_mountp;
struct xfs_dinode *dip;
struct xfs_buf *ibp;
- xfs_agino_t old_value;
int error;

ASSERT(xfs_verify_agino_or_null(mp, agno, next_agino));
@@ -2013,37 +2011,10 @@ xfs_iunlink_update_inode(
if (error)
return error;

- /* Make sure the old pointer isn't garbage. */
- old_value = be32_to_cpu(dip->di_next_unlinked);
- if (!xfs_verify_agino_or_null(mp, agno, old_value)) {
- xfs_inode_verifier_error(ip, -EFSCORRUPTED, __func__, dip,
- sizeof(*dip), __this_address);
- error = -EFSCORRUPTED;
- goto out;
- }
-
- /*
- * Since we're updating a linked list, we should never find that the
- * current pointer is the same as the new value, unless we're
- * terminating the list.
- */
- *old_next_agino = old_value;
- if (old_value == next_agino) {
- if (next_agino != NULLAGINO) {
- xfs_inode_verifier_error(ip, -EFSCORRUPTED, __func__,
- dip, sizeof(*dip), __this_address);
- error = -EFSCORRUPTED;
- }
- goto out;
- }
-
/* Ok, update the new pointer. */
xfs_iunlink_update_dinode(tp, agno, XFS_INO_TO_AGINO(mp, ip->i_ino),
ibp, dip, &ip->i_imap, next_agino);
return 0;
-out:
- xfs_trans_brelse(tp, ibp);
- return error;
}

static int
@@ -2079,19 +2050,15 @@ xfs_iunlink_insert_inode(
nip = list_first_entry_or_null(&agibp->b_pag->pag_ici_unlink_list,
struct xfs_inode, i_unlink);
if (nip) {
- xfs_agino_t old_agino;
-
ASSERT(next_agino == XFS_INO_TO_AGINO(mp, nip->i_ino));

/*
* There is already another inode in the bucket, so point this
* inode to the current head of the list.
*/
- error = xfs_iunlink_update_inode(tp, ip, agno, next_agino,
- &old_agino);
+ error = xfs_iunlink_update_inode(tp, ip, agno, next_agino);
if (error)
return error;
- ASSERT(old_agino == NULLAGINO);
} else {
ASSERT(next_agino == NULLAGINO);
}
@@ -2149,7 +2116,7 @@ xfs_iunlink_remove_inode(
struct xfs_agi *agi;
xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
- xfs_agino_t next_agino;
+ xfs_agino_t next_agino = NULLAGINO;
xfs_agino_t head_agino;
int error;

@@ -2169,23 +2136,21 @@ xfs_iunlink_remove_inode(
}

/*
- * Set our inode's next_unlinked pointer to NULL and then return
- * the old pointer value so that we can update whatever was previous
- * to us in the list to point to whatever was next in the list.
+ * Get the next agino in the list. If we are at the end of the list,
+ * then the previous inode's i_next_unlinked filed will get cleared.
*/
- error = xfs_iunlink_update_inode(tp, ip, agno, NULLAGINO, &next_agino);
+ if (ip != list_last_entry(&agibp->b_pag->pag_ici_unlink_list,
+ struct xfs_inode, i_unlink)) {
+ struct xfs_inode *nip = list_next_entry(ip, i_unlink);
+
+ next_agino = XFS_INO_TO_AGINO(mp, nip->i_ino);
+ }
+
+ /* Clear the on disk next unlinked pointer for this inode. */
+ error = xfs_iunlink_update_inode(tp, ip, agno, NULLAGINO);
if (error)
return error;

-#ifdef DEBUG
- {
- struct xfs_inode *nip = list_next_entry(ip, i_unlink);
- if (nip)
- ASSERT(next_agino == XFS_INO_TO_AGINO(mp, nip->i_ino));
- else
- ASSERT(next_agino == NULLAGINO);
- }
-#endif

if (ip != list_first_entry(&agibp->b_pag->pag_ici_unlink_list,
struct xfs_inode, i_unlink)) {
--
2.26.2.761.g0e0b3e54be