svn commit: r322221 - vendor-sys/illumos/dist/uts/common/fs/zfs
Andriy Gapon
avg at FreeBSD.org
Tue Aug 8 10:37:05 UTC 2017
Author: avg
Date: Tue Aug 8 10:37:03 2017
New Revision: 322221
URL: https://svnweb.freebsd.org/changeset/base/322221
Log:
7910 l2arc_write_buffers() may write beyond target_sz
illumos/illumos-gate at 16a7e5ac116c85d965007a5f201104b564e82210
https://github.com/illumos/illumos-gate/commit/16a7e5ac116c85d965007a5f201104b564e82210
https://www.illumos.org/issues/7910
It seems that the change in issue #6950 resurrected the problem that was
earlier fixed by the change in issue #5219.
Please also see the following FreeBSD bug report: https://bugs.freebsd.org/
bugzilla/show_bug.cgi?id=216178
Reviewed by: George Wilson <george.wilson at delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel at delphix.com>
Approved by: Robert Mustacchi <rm at joyent.com>
Author: Andriy Gapon <avg at FreeBSD.org>
Modified:
vendor-sys/illumos/dist/uts/common/fs/zfs/arc.c
Modified: vendor-sys/illumos/dist/uts/common/fs/zfs/arc.c
==============================================================================
--- vendor-sys/illumos/dist/uts/common/fs/zfs/arc.c Tue Aug 8 10:36:07 2017 (r322220)
+++ vendor-sys/illumos/dist/uts/common/fs/zfs/arc.c Tue Aug 8 10:37:03 2017 (r322221)
@@ -631,8 +631,8 @@ typedef struct arc_stats {
kstat_named_t arcstat_l2_abort_lowmem;
kstat_named_t arcstat_l2_cksum_bad;
kstat_named_t arcstat_l2_io_error;
- kstat_named_t arcstat_l2_size;
- kstat_named_t arcstat_l2_asize;
+ kstat_named_t arcstat_l2_lsize;
+ kstat_named_t arcstat_l2_psize;
kstat_named_t arcstat_l2_hdr_size;
kstat_named_t arcstat_memory_throttle_count;
kstat_named_t arcstat_meta_used;
@@ -3048,19 +3048,19 @@ arc_hdr_l2hdr_destroy(arc_buf_hdr_t *hdr)
{
l2arc_buf_hdr_t *l2hdr = &hdr->b_l2hdr;
l2arc_dev_t *dev = l2hdr->b_dev;
- uint64_t asize = arc_hdr_size(hdr);
+ uint64_t psize = arc_hdr_size(hdr);
ASSERT(MUTEX_HELD(&dev->l2ad_mtx));
ASSERT(HDR_HAS_L2HDR(hdr));
list_remove(&dev->l2ad_buflist, hdr);
- ARCSTAT_INCR(arcstat_l2_asize, -asize);
- ARCSTAT_INCR(arcstat_l2_size, -HDR_GET_LSIZE(hdr));
+ ARCSTAT_INCR(arcstat_l2_psize, -psize);
+ ARCSTAT_INCR(arcstat_l2_lsize, -HDR_GET_LSIZE(hdr));
- vdev_space_update(dev->l2ad_vdev, -asize, 0, 0);
+ vdev_space_update(dev->l2ad_vdev, -psize, 0, 0);
- (void) refcount_remove_many(&dev->l2ad_alloc, asize, hdr);
+ (void) refcount_remove_many(&dev->l2ad_alloc, psize, hdr);
arc_hdr_clear_flags(hdr, ARC_FLAG_HAS_L2HDR);
}
@@ -6522,8 +6522,8 @@ top:
list_remove(buflist, hdr);
arc_hdr_clear_flags(hdr, ARC_FLAG_HAS_L2HDR);
- ARCSTAT_INCR(arcstat_l2_asize, -arc_hdr_size(hdr));
- ARCSTAT_INCR(arcstat_l2_size, -HDR_GET_LSIZE(hdr));
+ ARCSTAT_INCR(arcstat_l2_psize, -arc_hdr_size(hdr));
+ ARCSTAT_INCR(arcstat_l2_lsize, -HDR_GET_LSIZE(hdr));
bytes_dropped += arc_hdr_size(hdr);
(void) refcount_remove_many(&dev->l2ad_alloc,
@@ -6782,7 +6782,7 @@ top:
/*
* This doesn't exist in the ARC. Destroy.
* arc_hdr_destroy() will call list_remove()
- * and decrement arcstat_l2_size.
+ * and decrement arcstat_l2_lsize.
*/
arc_change_state(arc_anon, hdr, hash_lock);
arc_hdr_destroy(hdr);
@@ -6824,7 +6824,7 @@ static uint64_t
l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz)
{
arc_buf_hdr_t *hdr, *hdr_prev, *head;
- uint64_t write_asize, write_psize, write_sz, headroom;
+ uint64_t write_asize, write_psize, write_lsize, headroom;
boolean_t full;
l2arc_write_callback_t *cb;
zio_t *pio, *wzio;
@@ -6833,7 +6833,7 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint
ASSERT3P(dev->l2ad_vdev, !=, NULL);
pio = NULL;
- write_sz = write_asize = write_psize = 0;
+ write_lsize = write_asize = write_psize = 0;
full = B_FALSE;
head = kmem_cache_alloc(hdr_l2only_cache, KM_PUSHPAGE);
arc_hdr_set_flags(head, ARC_FLAG_L2_WRITE_HEAD | ARC_FLAG_HAS_L2HDR);
@@ -6890,7 +6890,22 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint
continue;
}
- if ((write_asize + HDR_GET_LSIZE(hdr)) > target_sz) {
+ /*
+ * We rely on the L1 portion of the header below, so
+ * it's invalid for this header to have been evicted out
+ * of the ghost cache, prior to being written out. The
+ * ARC_FLAG_L2_WRITING bit ensures this won't happen.
+ */
+ ASSERT(HDR_HAS_L1HDR(hdr));
+
+ ASSERT3U(HDR_GET_PSIZE(hdr), >, 0);
+ ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL);
+ ASSERT3U(arc_hdr_size(hdr), >, 0);
+ uint64_t psize = arc_hdr_size(hdr);
+ uint64_t asize = vdev_psize_to_asize(dev->l2ad_vdev,
+ psize);
+
+ if ((write_asize + asize) > target_sz) {
full = B_TRUE;
mutex_exit(hash_lock);
break;
@@ -6923,21 +6938,8 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint
list_insert_head(&dev->l2ad_buflist, hdr);
mutex_exit(&dev->l2ad_mtx);
- /*
- * We rely on the L1 portion of the header below, so
- * it's invalid for this header to have been evicted out
- * of the ghost cache, prior to being written out. The
- * ARC_FLAG_L2_WRITING bit ensures this won't happen.
- */
- ASSERT(HDR_HAS_L1HDR(hdr));
+ (void) refcount_add_many(&dev->l2ad_alloc, psize, hdr);
- ASSERT3U(HDR_GET_PSIZE(hdr), >, 0);
- ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL);
- ASSERT3U(arc_hdr_size(hdr), >, 0);
- uint64_t size = arc_hdr_size(hdr);
-
- (void) refcount_add_many(&dev->l2ad_alloc, size, hdr);
-
/*
* Normally the L2ARC can use the hdr's data, but if
* we're sharing data between the hdr and one of its
@@ -6952,20 +6954,18 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint
* lifetime of the ZIO and be cleaned up afterwards, we
* add it to the l2arc_free_on_write queue.
*/
- uint64_t asize = vdev_psize_to_asize(dev->l2ad_vdev,
- size);
abd_t *to_write;
- if (!HDR_SHARED_DATA(hdr) && size == asize) {
+ if (!HDR_SHARED_DATA(hdr) && psize == asize) {
to_write = hdr->b_l1hdr.b_pabd;
} else {
to_write = abd_alloc_for_io(asize,
HDR_ISTYPE_METADATA(hdr));
- abd_copy(to_write, hdr->b_l1hdr.b_pabd, size);
- if (asize != size) {
- abd_zero_off(to_write, size,
- asize - size);
+ abd_copy(to_write, hdr->b_l1hdr.b_pabd, psize);
+ if (asize != psize) {
+ abd_zero_off(to_write, psize,
+ asize - psize);
}
- l2arc_free_abd_on_write(to_write, size,
+ l2arc_free_abd_on_write(to_write, asize,
arc_buf_type(hdr));
}
wzio = zio_write_phys(pio, dev->l2ad_vdev,
@@ -6974,12 +6974,12 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint
ZIO_PRIORITY_ASYNC_WRITE,
ZIO_FLAG_CANFAIL, B_FALSE);
- write_sz += HDR_GET_LSIZE(hdr);
+ write_lsize += HDR_GET_LSIZE(hdr);
DTRACE_PROBE2(l2arc__write, vdev_t *, dev->l2ad_vdev,
zio_t *, wzio);
- write_asize += size;
- write_psize += asize;
+ write_psize += psize;
+ write_asize += asize;
dev->l2ad_hand += asize;
mutex_exit(hash_lock);
@@ -6995,7 +6995,7 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint
/* No buffers selected for writing? */
if (pio == NULL) {
- ASSERT0(write_sz);
+ ASSERT0(write_lsize);
ASSERT(!HDR_HAS_L1HDR(head));
kmem_cache_free(hdr_l2only_cache, head);
return (0);
@@ -7003,10 +7003,10 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint
ASSERT3U(write_asize, <=, target_sz);
ARCSTAT_BUMP(arcstat_l2_writes_sent);
- ARCSTAT_INCR(arcstat_l2_write_bytes, write_asize);
- ARCSTAT_INCR(arcstat_l2_size, write_sz);
- ARCSTAT_INCR(arcstat_l2_asize, write_asize);
- vdev_space_update(dev->l2ad_vdev, write_asize, 0, 0);
+ ARCSTAT_INCR(arcstat_l2_write_bytes, write_psize);
+ ARCSTAT_INCR(arcstat_l2_lsize, write_lsize);
+ ARCSTAT_INCR(arcstat_l2_psize, write_psize);
+ vdev_space_update(dev->l2ad_vdev, write_psize, 0, 0);
/*
* Bump device hand to the device start if it is approaching the end.
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