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xfs: merge xfs_reclaim_inodes_ag into xfs_inode_walk_ag
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Merge these two inode walk loops together, since they're pretty similar
now.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
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Darrick J. Wong committed Jun 3, 2021
1 parent 9d5ee83 commit f1bc5c5
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Showing 3 changed files with 53 additions and 115 deletions.
162 changes: 48 additions & 114 deletions fs/xfs/xfs_icache.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -43,6 +43,7 @@ enum xfs_icwalk_goal {

/* Goals directly associated with tagged inodes. */
XFS_ICWALK_BLOCKGC = XFS_ICI_BLOCKGC_TAG,
XFS_ICWALK_RECLAIM = XFS_ICI_RECLAIM_TAG,
};

#define XFS_ICWALK_NULL_TAG (-1U)
Expand All @@ -67,9 +68,13 @@ static int xfs_icwalk_ag(struct xfs_perag *pag,
#define XFS_ICWALK_FLAG_DROP_GDQUOT (1U << 30)
#define XFS_ICWALK_FLAG_DROP_PDQUOT (1U << 29)

/* Stop scanning after icw_scan_limit inodes. */
#define XFS_ICWALK_FLAG_SCAN_LIMIT (1U << 28)

#define XFS_ICWALK_PRIVATE_FLAGS (XFS_ICWALK_FLAG_DROP_UDQUOT | \
XFS_ICWALK_FLAG_DROP_GDQUOT | \
XFS_ICWALK_FLAG_DROP_PDQUOT)
XFS_ICWALK_FLAG_DROP_PDQUOT | \
XFS_ICWALK_FLAG_SCAN_LIMIT)

/*
* Allocate and initialise an xfs_inode.
Expand Down Expand Up @@ -760,17 +765,6 @@ xfs_icache_inode_is_allocated(
return 0;
}

/*
* The inode lookup is done in batches to keep the amount of lock traffic and
* radix tree lookups to a minimum. The batch size is a trade off between
* lookup reduction and stack usage. This is in the reclaim path, so we can't
* be too greedy.
*
* XXX: This will be moved closer to xfs_icwalk* once we get rid of the
* separate reclaim walk functions.
*/
#define XFS_LOOKUP_BATCH 32

#ifdef CONFIG_XFS_QUOTA
/* Decide if we want to grab this inode to drop its dquots. */
static bool
Expand Down Expand Up @@ -880,7 +874,7 @@ xfs_dqrele_all_inodes(
* Return true if we grabbed it, false otherwise.
*/
static bool
xfs_reclaim_inode_grab(
xfs_reclaim_igrab(
struct xfs_inode *ip)
{
ASSERT(rcu_read_lock_held());
Expand Down Expand Up @@ -990,108 +984,13 @@ xfs_reclaim_inode(
xfs_iflags_clear(ip, XFS_IRECLAIM);
}

/*
* Walk the AGs and reclaim the inodes in them. Even if the filesystem is
* corrupted, we still want to try to reclaim all the inodes. If we don't,
* then a shut down during filesystem unmount reclaim walk leak all the
* unreclaimed inodes.
*
* Returns non-zero if any AGs or inodes were skipped in the reclaim pass
* so that callers that want to block until all dirty inodes are written back
* and reclaimed can sanely loop.
*/
static void
xfs_reclaim_inodes_ag(
struct xfs_mount *mp,
int *nr_to_scan)
{
struct xfs_perag *pag;
xfs_agnumber_t ag = 0;

while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_RECLAIM_TAG))) {
unsigned long first_index = 0;
int done = 0;
int nr_found = 0;

ag = pag->pag_agno + 1;

first_index = READ_ONCE(pag->pag_ici_reclaim_cursor);
do {
struct xfs_inode *batch[XFS_LOOKUP_BATCH];
int i;

rcu_read_lock();
nr_found = radix_tree_gang_lookup_tag(
&pag->pag_ici_root,
(void **)batch, first_index,
XFS_LOOKUP_BATCH,
XFS_ICI_RECLAIM_TAG);
if (!nr_found) {
done = 1;
rcu_read_unlock();
break;
}

/*
* Grab the inodes before we drop the lock. if we found
* nothing, nr == 0 and the loop will be skipped.
*/
for (i = 0; i < nr_found; i++) {
struct xfs_inode *ip = batch[i];

if (done || !xfs_reclaim_inode_grab(ip))
batch[i] = NULL;

/*
* Update the index for the next lookup. Catch
* overflows into the next AG range which can
* occur if we have inodes in the last block of
* the AG and we are currently pointing to the
* last inode.
*
* Because we may see inodes that are from the
* wrong AG due to RCU freeing and
* reallocation, only update the index if it
* lies in this AG. It was a race that lead us
* to see this inode, so another lookup from
* the same index will not find it again.
*/
if (XFS_INO_TO_AGNO(mp, ip->i_ino) !=
pag->pag_agno)
continue;
first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino))
done = 1;
}

/* unlock now we've grabbed the inodes. */
rcu_read_unlock();

for (i = 0; i < nr_found; i++) {
if (batch[i])
xfs_reclaim_inode(batch[i], pag);
}

*nr_to_scan -= XFS_LOOKUP_BATCH;
cond_resched();
} while (nr_found && !done && *nr_to_scan > 0);

if (done)
first_index = 0;
WRITE_ONCE(pag->pag_ici_reclaim_cursor, first_index);
xfs_perag_put(pag);
}
}

void
xfs_reclaim_inodes(
struct xfs_mount *mp)
{
int nr_to_scan = INT_MAX;

while (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_RECLAIM_TAG)) {
xfs_ail_push_all_sync(mp->m_ail);
xfs_reclaim_inodes_ag(mp, &nr_to_scan);
xfs_icwalk(mp, XFS_ICWALK_RECLAIM, NULL);
}
}

Expand All @@ -1107,11 +1006,16 @@ xfs_reclaim_inodes_nr(
struct xfs_mount *mp,
int nr_to_scan)
{
struct xfs_eofblocks eofb = {
.eof_flags = XFS_ICWALK_FLAG_SCAN_LIMIT,
.icw_scan_limit = nr_to_scan,
};

/* kick background reclaimer and push the AIL */
xfs_reclaim_work_queue(mp);
xfs_ail_push_all(mp->m_ail);

xfs_reclaim_inodes_ag(mp, &nr_to_scan);
xfs_icwalk(mp, XFS_ICWALK_RECLAIM, &eofb);
return 0;
}

Expand Down Expand Up @@ -1221,9 +1125,8 @@ xfs_reclaim_worker(
{
struct xfs_mount *mp = container_of(to_delayed_work(work),
struct xfs_mount, m_reclaim_work);
int nr_to_scan = INT_MAX;

xfs_reclaim_inodes_ag(mp, &nr_to_scan);
xfs_icwalk(mp, XFS_ICWALK_RECLAIM, NULL);
xfs_reclaim_work_queue(mp);
}

Expand Down Expand Up @@ -1693,6 +1596,15 @@ xfs_blockgc_free_quota(

/* XFS Inode Cache Walking Code */

/*
* The inode lookup is done in batches to keep the amount of lock traffic and
* radix tree lookups to a minimum. The batch size is a trade off between
* lookup reduction and stack usage. This is in the reclaim path, so we can't
* be too greedy.
*/
#define XFS_LOOKUP_BATCH 32


/*
* Decide if we want to grab this inode in anticipation of doing work towards
* the goal.
Expand All @@ -1707,6 +1619,8 @@ xfs_icwalk_igrab(
return xfs_dqrele_igrab(ip);
case XFS_ICWALK_BLOCKGC:
return xfs_blockgc_igrab(ip);
case XFS_ICWALK_RECLAIM:
return xfs_reclaim_igrab(ip);
default:
return false;
}
Expand All @@ -1720,6 +1634,7 @@ static inline int
xfs_icwalk_process_inode(
enum xfs_icwalk_goal goal,
struct xfs_inode *ip,
struct xfs_perag *pag,
struct xfs_eofblocks *eofb)
{
int error = 0;
Expand All @@ -1731,6 +1646,9 @@ xfs_icwalk_process_inode(
case XFS_ICWALK_BLOCKGC:
error = xfs_blockgc_scan_inode(ip, eofb);
break;
case XFS_ICWALK_RECLAIM:
xfs_reclaim_inode(ip, pag);
break;
}
return error;
}
Expand All @@ -1755,7 +1673,10 @@ xfs_icwalk_ag(
restart:
done = false;
skipped = 0;
first_index = 0;
if (goal == XFS_ICWALK_RECLAIM)
first_index = READ_ONCE(pag->pag_ici_reclaim_cursor);
else
first_index = 0;
nr_found = 0;
do {
struct xfs_inode *batch[XFS_LOOKUP_BATCH];
Expand All @@ -1776,6 +1697,7 @@ xfs_icwalk_ag(
XFS_LOOKUP_BATCH, tag);

if (!nr_found) {
done = true;
rcu_read_unlock();
break;
}
Expand Down Expand Up @@ -1815,7 +1737,8 @@ xfs_icwalk_ag(
for (i = 0; i < nr_found; i++) {
if (!batch[i])
continue;
error = xfs_icwalk_process_inode(goal, batch[i], eofb);
error = xfs_icwalk_process_inode(goal, batch[i], pag,
eofb);
if (error == -EAGAIN) {
skipped++;
continue;
Expand All @@ -1830,8 +1753,19 @@ xfs_icwalk_ag(

cond_resched();

if (eofb && (eofb->eof_flags & XFS_ICWALK_FLAG_SCAN_LIMIT)) {
eofb->icw_scan_limit -= XFS_LOOKUP_BATCH;
if (eofb->icw_scan_limit <= 0)
break;
}
} while (nr_found && !done);

if (goal == XFS_ICWALK_RECLAIM) {
if (done)
first_index = 0;
WRITE_ONCE(pag->pag_ici_reclaim_cursor, first_index);
}

if (skipped) {
delay(1);
goto restart;
Expand Down
1 change: 1 addition & 0 deletions fs/xfs/xfs_icache.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,7 @@ struct xfs_eofblocks {
kgid_t eof_gid;
prid_t eof_prid;
__u64 eof_min_file_size;
int icw_scan_limit;
};

/*
Expand Down
5 changes: 4 additions & 1 deletion fs/xfs/xfs_trace.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3898,6 +3898,7 @@ DECLARE_EVENT_CLASS(xfs_eofblocks_class,
__field(uint32_t, gid)
__field(prid_t, prid)
__field(__u64, min_file_size)
__field(int, scan_limit)
__field(unsigned long, caller_ip)
),
TP_fast_assign(
Expand All @@ -3909,15 +3910,17 @@ DECLARE_EVENT_CLASS(xfs_eofblocks_class,
eofb->eof_gid) : 0;
__entry->prid = eofb ? eofb->eof_prid : 0;
__entry->min_file_size = eofb ? eofb->eof_min_file_size : 0;
__entry->scan_limit = eofb ? eofb->icw_scan_limit : 0;
__entry->caller_ip = caller_ip;
),
TP_printk("dev %d:%d flags 0x%x uid %u gid %u prid %u minsize %llu caller %pS",
TP_printk("dev %d:%d flags 0x%x uid %u gid %u prid %u minsize %llu scan_limit %d caller %pS",
MAJOR(__entry->dev), MINOR(__entry->dev),
__entry->flags,
__entry->uid,
__entry->gid,
__entry->prid,
__entry->min_file_size,
__entry->scan_limit,
(char *)__entry->caller_ip)
);
#define DEFINE_EOFBLOCKS_EVENT(name) \
Expand Down

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