From 025f8b2e7479a807547131cc6bb4851d8950bb9b Mon Sep 17 00:00:00 2001 From: Alexander Motin Date: Wed, 13 Nov 2024 10:31:50 -0500 Subject: [PATCH] L2ARC: Move different stats updates earlier ..., before we make the header or the log block visible to others. It should fix assertion on allocated space going negative if the header is freed once the lock is dropped, while the write is still going. Reviewed-by: Brian Behlendorf Reviewed-by: Rob Norris Signed-off-by: Alexander Motin Sponsored by: iXsystems, Inc. Closes #16040 Closes #16743 --- module/zfs/arc.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/module/zfs/arc.c b/module/zfs/arc.c index 76dc0b19139d..2ece7d67704f 100644 --- a/module/zfs/arc.c +++ b/module/zfs/arc.c @@ -9287,6 +9287,14 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz) hdr->b_l2hdr.b_hits = 0; hdr->b_l2hdr.b_arcs_state = hdr->b_l1hdr.b_state->arcs_state; + arc_hdr_set_flags(hdr, ARC_FLAG_HAS_L2HDR | + ARC_FLAG_L2_WRITING); + + (void) zfs_refcount_add_many(&dev->l2ad_alloc, + arc_hdr_size(hdr), hdr); + l2arc_hdr_arcstats_increment(hdr); + vdev_space_update(dev->l2ad_vdev, asize, 0, 0); + mutex_enter(&dev->l2ad_mtx); if (pio == NULL) { /* @@ -9298,12 +9306,6 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz) } list_insert_head(&dev->l2ad_buflist, hdr); mutex_exit(&dev->l2ad_mtx); - arc_hdr_set_flags(hdr, ARC_FLAG_HAS_L2HDR | - ARC_FLAG_L2_WRITING); - - (void) zfs_refcount_add_many(&dev->l2ad_alloc, - arc_hdr_size(hdr), hdr); - l2arc_hdr_arcstats_increment(hdr); boolean_t commit = l2arc_log_blk_insert(dev, hdr); mutex_exit(hash_lock); @@ -9333,7 +9335,6 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz) write_psize += psize; write_asize += asize; dev->l2ad_hand += asize; - vdev_space_update(dev->l2ad_vdev, asize, 0, 0); if (commit) { /* l2ad_hand will be adjusted inside. */ @@ -10585,6 +10586,8 @@ l2arc_log_blk_commit(l2arc_dev_t *dev, zio_t *pio, l2arc_write_callback_t *cb) (void) zio_nowait(wzio); dev->l2ad_hand += asize; + vdev_space_update(dev->l2ad_vdev, asize, 0, 0); + /* * Include the committed log block's pointer in the list of pointers * to log blocks present in the L2ARC device. @@ -10598,7 +10601,6 @@ l2arc_log_blk_commit(l2arc_dev_t *dev, zio_t *pio, l2arc_write_callback_t *cb) zfs_refcount_add_many(&dev->l2ad_lb_asize, asize, lb_ptr_buf); zfs_refcount_add(&dev->l2ad_lb_count, lb_ptr_buf); mutex_exit(&dev->l2ad_mtx); - vdev_space_update(dev->l2ad_vdev, asize, 0, 0); /* bump the kstats */ ARCSTAT_INCR(arcstat_l2_write_bytes, asize);