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authorArne Jansen <[email protected]>2015-09-11 09:18:56 -0700
committerBrian Behlendorf <[email protected]>2015-09-11 11:14:38 -0700
commit4e0f33ffe018b07021f627328f0a207550d1b374 (patch)
treeb4b6b7a142ae2bd29ead4a99b6e292911a097cf3 /module
parent9965059ab9991a5fc7df9a489021e73880b3bcc0 (diff)
Illumos 6214 - zpools going south
6214 zpools going south Reviewed by: Igor Kozhukhov <[email protected]> Reviewed by: George Wilson <[email protected]> Reviewed by: Dan McDonald <[email protected]> Reviewed by: Saso Kiselkov <[email protected]> References: https://www.illumos.org/issues/6214 http://cr.illumos.org/~webrev/sensille/6214_zpools_going_south/ Porting Notes: Reintroduce b_compress to the l2arc_buf_hdr_t. In commit b9541d6 the compression flags were moved to the generic b_flags in the arc_buf_hdr_t. This is a problem because l2arc_compress_buf() may manipulate the compression flags and this can only be done safely under the hash lock which is not held. See Illumos 6214 for a detailed analysis of the race. HDR_GET_COMPRESS() macro was removed from arc_buf_info(). Ported-by: Brian Behlendorf <[email protected]> Closes #3757
Diffstat (limited to 'module')
-rw-r--r--module/zfs/arc.c35
1 files changed, 15 insertions, 20 deletions
diff --git a/module/zfs/arc.c b/module/zfs/arc.c
index 00d989028..7cd4e76f2 100644
--- a/module/zfs/arc.c
+++ b/module/zfs/arc.c
@@ -677,15 +677,6 @@ static arc_buf_hdr_t arc_eviction_hdr;
#define HDR_HAS_L1HDR(hdr) ((hdr)->b_flags & ARC_FLAG_HAS_L1HDR)
#define HDR_HAS_L2HDR(hdr) ((hdr)->b_flags & ARC_FLAG_HAS_L2HDR)
-/* For storing compression mode in b_flags */
-#define HDR_COMPRESS_OFFSET 24
-#define HDR_COMPRESS_NBITS 7
-
-#define HDR_GET_COMPRESS(hdr) ((enum zio_compress)BF32_GET(hdr->b_flags, \
- HDR_COMPRESS_OFFSET, HDR_COMPRESS_NBITS))
-#define HDR_SET_COMPRESS(hdr, cmp) BF32_SET(hdr->b_flags, \
- HDR_COMPRESS_OFFSET, HDR_COMPRESS_NBITS, (cmp))
-
/*
* Other sizes
*/
@@ -1483,7 +1474,7 @@ arc_buf_info(arc_buf_t *ab, arc_buf_info_t *abi, int state_index)
if (l2hdr) {
abi->abi_l2arc_dattr = l2hdr->b_daddr;
abi->abi_l2arc_asize = l2hdr->b_asize;
- abi->abi_l2arc_compress = HDR_GET_COMPRESS(hdr);
+ abi->abi_l2arc_compress = l2hdr->b_compress;
abi->abi_l2arc_hits = l2hdr->b_hits;
}
@@ -1954,7 +1945,7 @@ arc_buf_l2_cdata_free(arc_buf_hdr_t *hdr)
* separately compressed buffer, so there's nothing to free (it
* points to the same buffer as the arc_buf_t's b_data field).
*/
- if (HDR_GET_COMPRESS(hdr) == ZIO_COMPRESS_OFF) {
+ if (hdr->b_l2hdr.b_compress == ZIO_COMPRESS_OFF) {
hdr->b_l1hdr.b_tmp_cdata = NULL;
return;
}
@@ -1963,12 +1954,12 @@ arc_buf_l2_cdata_free(arc_buf_hdr_t *hdr)
* There's nothing to free since the buffer was all zero's and
* compressed to a zero length buffer.
*/
- if (HDR_GET_COMPRESS(hdr) == ZIO_COMPRESS_EMPTY) {
+ if (hdr->b_l2hdr.b_compress == ZIO_COMPRESS_EMPTY) {
ASSERT3P(hdr->b_l1hdr.b_tmp_cdata, ==, NULL);
return;
}
- ASSERT(L2ARC_IS_VALID_COMPRESS(HDR_GET_COMPRESS(hdr)));
+ ASSERT(L2ARC_IS_VALID_COMPRESS(hdr->b_l2hdr.b_compress));
arc_buf_free_on_write(hdr->b_l1hdr.b_tmp_cdata,
hdr->b_size, zio_data_buf_free);
@@ -4429,7 +4420,7 @@ top:
(vd = hdr->b_l2hdr.b_dev->l2ad_vdev) != NULL) {
devw = hdr->b_l2hdr.b_dev->l2ad_writing;
addr = hdr->b_l2hdr.b_daddr;
- b_compress = HDR_GET_COMPRESS(hdr);
+ b_compress = hdr->b_l2hdr.b_compress;
b_asize = hdr->b_l2hdr.b_asize;
/*
* Lock out device removal.
@@ -6037,6 +6028,8 @@ l2arc_read_done(zio_t *zio)
if (cb->l2rcb_compress != ZIO_COMPRESS_OFF)
l2arc_decompress_zio(zio, hdr, cb->l2rcb_compress);
ASSERT(zio->io_data != NULL);
+ ASSERT3U(zio->io_size, ==, hdr->b_size);
+ ASSERT3U(BP_GET_LSIZE(&cb->l2rcb_bp), ==, hdr->b_size);
/*
* Check this survived the L2ARC journey.
@@ -6073,7 +6066,7 @@ l2arc_read_done(zio_t *zio)
ASSERT(!pio || pio->io_child_type == ZIO_CHILD_LOGICAL);
zio_nowait(zio_read(pio, cb->l2rcb_spa, &cb->l2rcb_bp,
- buf->b_data, zio->io_size, arc_read_done, buf,
+ buf->b_data, hdr->b_size, arc_read_done, buf,
zio->io_priority, cb->l2rcb_flags, &cb->l2rcb_zb));
}
}
@@ -6381,7 +6374,7 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz,
* can't access without holding the ARC list locks
* (which we want to avoid during compression/writing)
*/
- HDR_SET_COMPRESS(hdr, ZIO_COMPRESS_OFF);
+ hdr->b_l2hdr.b_compress = ZIO_COMPRESS_OFF;
hdr->b_l2hdr.b_asize = hdr->b_size;
hdr->b_l2hdr.b_hits = 0;
hdr->b_l1hdr.b_tmp_cdata = hdr->b_l1hdr.b_buf->b_data;
@@ -6587,7 +6580,7 @@ l2arc_compress_buf(arc_buf_hdr_t *hdr)
l2hdr = &hdr->b_l2hdr;
ASSERT(HDR_HAS_L1HDR(hdr));
- ASSERT(HDR_GET_COMPRESS(hdr) == ZIO_COMPRESS_OFF);
+ ASSERT3U(l2hdr->b_compress, ==, ZIO_COMPRESS_OFF);
ASSERT(hdr->b_l1hdr.b_tmp_cdata != NULL);
len = l2hdr->b_asize;
@@ -6605,7 +6598,7 @@ l2arc_compress_buf(arc_buf_hdr_t *hdr)
if (csize == 0) {
/* zero block, indicate that there's nothing to write */
zio_data_buf_free(cdata, len);
- HDR_SET_COMPRESS(hdr, ZIO_COMPRESS_EMPTY);
+ l2hdr->b_compress = ZIO_COMPRESS_EMPTY;
l2hdr->b_asize = 0;
hdr->b_l1hdr.b_tmp_cdata = NULL;
ARCSTAT_BUMP(arcstat_l2_compress_zeros);
@@ -6615,7 +6608,7 @@ l2arc_compress_buf(arc_buf_hdr_t *hdr)
* Compression succeeded, we'll keep the cdata around for
* writing and release it afterwards.
*/
- HDR_SET_COMPRESS(hdr, ZIO_COMPRESS_LZ4);
+ l2hdr->b_compress = ZIO_COMPRESS_LZ4;
l2hdr->b_asize = csize;
hdr->b_l1hdr.b_tmp_cdata = cdata;
ARCSTAT_BUMP(arcstat_l2_compress_successes);
@@ -6702,9 +6695,11 @@ l2arc_decompress_zio(zio_t *zio, arc_buf_hdr_t *hdr, enum zio_compress c)
static void
l2arc_release_cdata_buf(arc_buf_hdr_t *hdr)
{
- enum zio_compress comp = HDR_GET_COMPRESS(hdr);
+ enum zio_compress comp;
ASSERT(HDR_HAS_L1HDR(hdr));
+ ASSERT(HDR_HAS_L2HDR(hdr));
+ comp = hdr->b_l2hdr.b_compress;
ASSERT(comp == ZIO_COMPRESS_OFF || L2ARC_IS_VALID_COMPRESS(comp));
if (comp == ZIO_COMPRESS_OFF) {