xfs: unwind xfs_extent_busy_clear

The current structure of xfs_extent_busy_clear that locks the first busy
extent in each AG and unlocks when switching to a new AG makes sparse
unhappy as the lock critical section tracking can't cope with taking the
lock conditionally and inside a loop.

Rewrite xfs_extent_busy_clear so that it has an outer loop only advancing
when moving to a new AG, and an inner loop that consumes busy extents for
the given AG to make life easier for sparse and to also make this logic
more obvious to humans.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
This commit is contained in:
Christoph Hellwig 2024-04-05 08:07:09 +02:00 committed by Chandan Babu R
parent e78a3ce283
commit c37d6ed874

View File

@ -540,21 +540,6 @@ xfs_extent_busy_clear_one(
return true;
}
static void
xfs_extent_busy_put_pag(
struct xfs_perag *pag,
bool wakeup)
__releases(pag->pagb_lock)
{
if (wakeup) {
pag->pagb_gen++;
wake_up_all(&pag->pagb_wait);
}
spin_unlock(&pag->pagb_lock);
xfs_perag_put(pag);
}
/*
* Remove all extents on the passed in list from the busy extents tree.
* If do_discard is set skip extents that need to be discarded, and mark
@ -566,27 +551,33 @@ xfs_extent_busy_clear(
struct list_head *list,
bool do_discard)
{
struct xfs_extent_busy *busyp, *n;
struct xfs_perag *pag = NULL;
xfs_agnumber_t agno = NULLAGNUMBER;
bool wakeup = false;
struct xfs_extent_busy *busyp, *next;
list_for_each_entry_safe(busyp, n, list, list) {
if (busyp->agno != agno) {
if (pag)
xfs_extent_busy_put_pag(pag, wakeup);
agno = busyp->agno;
pag = xfs_perag_get(mp, agno);
spin_lock(&pag->pagb_lock);
wakeup = false;
busyp = list_first_entry_or_null(list, typeof(*busyp), list);
if (!busyp)
return;
do {
bool wakeup = false;
struct xfs_perag *pag;
pag = xfs_perag_get(mp, busyp->agno);
spin_lock(&pag->pagb_lock);
do {
next = list_next_entry(busyp, list);
if (xfs_extent_busy_clear_one(pag, busyp, do_discard))
wakeup = true;
busyp = next;
} while (!list_entry_is_head(busyp, list, list) &&
busyp->agno == pag->pag_agno);
if (wakeup) {
pag->pagb_gen++;
wake_up_all(&pag->pagb_wait);
}
if (xfs_extent_busy_clear_one(pag, busyp, do_discard))
wakeup = true;
}
if (pag)
xfs_extent_busy_put_pag(pag, wakeup);
spin_unlock(&pag->pagb_lock);
xfs_perag_put(pag);
} while (!list_entry_is_head(busyp, list, list));
}
/*