From 5a6765cf8cad21d22dc172b4089b655c9270d16a Mon Sep 17 00:00:00 2001
From: cao <cao.xuewen@zte.com.cn>
Date: Fri, 21 Oct 2016 02:24:01 +0800
Subject: [PATCH] Fix coverity defects: CID 147472
CID 147472: Type: 'Constant' variable guards dead code
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: cao.xuewen <cao.xuewen@zte.com.cn>
Closes #5288
---
include/sys/dmu.h | 2 ++
module/zfs/dmu.c | 9 +++++++--
module/zfs/zfs_vnops.c | 8 ++++++--
3 files changed, 15 insertions(+), 4 deletions(-)
diff --git a/include/sys/dmu.h b/include/sys/dmu.h
index ec89e90184..9d61d94ee0 100644
--- a/include/sys/dmu.h
+++ b/include/sys/dmu.h
@@ -744,6 +744,7 @@ struct arc_buf *dmu_request_arcbuf(dmu_buf_t *handle, int size);
void dmu_return_arcbuf(struct arc_buf *buf);
void dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, struct arc_buf *buf,
dmu_tx_t *tx);
+#ifdef HAVE_UIO_ZEROCOPY
int dmu_xuio_init(struct xuio *uio, int niov);
void dmu_xuio_fini(struct xuio *uio);
int dmu_xuio_add(struct xuio *uio, struct arc_buf *abuf, offset_t off,
@@ -751,6 +752,7 @@ int dmu_xuio_add(struct xuio *uio, struct arc_buf *abuf, offset_t off,
int dmu_xuio_cnt(struct xuio *uio);
struct arc_buf *dmu_xuio_arcbuf(struct xuio *uio, int i);
void dmu_xuio_clear(struct xuio *uio, int i);
+#endif /* HAVE_UIO_ZEROCOPY */
void xuio_stat_wbuf_copied(void);
void xuio_stat_wbuf_nocopy(void);
diff --git a/module/zfs/dmu.c b/module/zfs/dmu.c
index 80185706cd..7da49af7b5 100644
--- a/module/zfs/dmu.c
+++ b/module/zfs/dmu.c
@@ -987,6 +987,7 @@ static xuio_stats_t xuio_stats = {
atomic_add_64(&xuio_stats.stat.value.ui64, (val))
#define XUIOSTAT_BUMP(stat) XUIOSTAT_INCR(stat, 1)
+#ifdef HAVE_UIO_ZEROCOPY
int
dmu_xuio_init(xuio_t *xuio, int nblk)
{
@@ -1071,6 +1072,7 @@ dmu_xuio_clear(xuio_t *xuio, int i)
ASSERT(i < priv->cnt);
priv->bufs[i] = NULL;
}
+#endif /* HAVE_UIO_ZEROCOPY */
static void
xuio_stat_init(void)
@@ -1111,7 +1113,9 @@ dmu_read_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size)
{
dmu_buf_t **dbp;
int numbufs, i, err;
+#ifdef HAVE_UIO_ZEROCOPY
xuio_t *xuio = NULL;
+#endif
/*
* NB: we could do this block-at-a-time, but it's nice
@@ -1132,6 +1136,7 @@ dmu_read_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size)
bufoff = uio->uio_loffset - db->db_offset;
tocpy = MIN(db->db_size - bufoff, size);
+#ifdef HAVE_UIO_ZEROCOPY
if (xuio) {
dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
arc_buf_t *dbuf_abuf = dbi->db_buf;
@@ -1146,10 +1151,10 @@ dmu_read_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size)
XUIOSTAT_BUMP(xuiostat_rbuf_nocopy);
else
XUIOSTAT_BUMP(xuiostat_rbuf_copied);
- } else {
+ } else
+#endif
err = uiomove((char *)db->db_data + bufoff, tocpy,
UIO_READ, uio);
- }
if (err)
break;
diff --git a/module/zfs/zfs_vnops.c b/module/zfs/zfs_vnops.c
index 116bb2730f..8ac14df003 100644
--- a/module/zfs/zfs_vnops.c
+++ b/module/zfs/zfs_vnops.c
@@ -596,14 +596,16 @@ zfs_write(struct inode *ip, uio_t *uio, int ioflag, cred_t *cr)
arc_buf_t *abuf;
const iovec_t *aiov = NULL;
xuio_t *xuio = NULL;
- int i_iov = 0;
- const iovec_t *iovp = uio->uio_iov;
int write_eof;
int count = 0;
sa_bulk_attr_t bulk[4];
uint64_t mtime[2], ctime[2];
uint32_t uid;
+#ifdef HAVE_UIO_ZEROCOPY
+ int i_iov = 0;
+ const iovec_t *iovp = uio->uio_iov;
ASSERTV(int iovcnt = uio->uio_iovcnt);
+#endif
/*
* Fasttrack empty write
@@ -726,6 +728,7 @@ zfs_write(struct inode *ip, uio_t *uio, int ioflag, cred_t *cr)
}
if (xuio && abuf == NULL) {
+#ifdef HAVE_UIO_ZEROCOPY
ASSERT(i_iov < iovcnt);
ASSERT3U(uio->uio_segflg, !=, UIO_BVEC);
aiov = &iovp[i_iov];
@@ -735,6 +738,7 @@ zfs_write(struct inode *ip, uio_t *uio, int ioflag, cred_t *cr)
((char *)aiov->iov_base - (char *)abuf->b_data +
aiov->iov_len == arc_buf_size(abuf)));
i_iov++;
+#endif
} else if (abuf == NULL && n >= max_blksz &&
woff >= zp->z_size &&
P2PHASE(woff, max_blksz) == 0 &&