[SG] Get rid of __sg_mark_end()
sg_mark_end() overwrites the page_link information, but all users want
__sg_mark_end() behaviour where we just set the end bit. That is the most
natural way to use the sg list, since you'll fill it in and then mark the
end point.
So change sg_mark_end() to only set the termination bit. Add a sg_magic
debug check as well, and clear a chain pointer if it is set.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 56f2646..54fd385 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -1369,7 +1369,7 @@
} /* segments in rq */
if (sg)
- __sg_mark_end(sg);
+ sg_mark_end(sg);
return nsegs;
}
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 61fdaf0..88de771 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -785,7 +785,7 @@
* end-of-list
*/
if (!left)
- sg_mark_end(sgl, this);
+ sg_mark_end(&sgl[this - 1]);
/*
* don't allow subsequent mempool allocs to sleep, it would
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index d5e1876..2597350 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -188,21 +188,23 @@
/**
* sg_mark_end - Mark the end of the scatterlist
- * @sgl: Scatterlist
- * @nents: Number of entries in sgl
+ * @sg: SG entryScatterlist
*
* Description:
- * Marks the last entry as the termination point for sg_next()
+ * Marks the passed in sg entry as the termination point for the sg
+ * table. A call to sg_next() on this entry will return NULL.
*
**/
-static inline void sg_mark_end(struct scatterlist *sgl, unsigned int nents)
+static inline void sg_mark_end(struct scatterlist *sg)
{
- sgl[nents - 1].page_link = 0x02;
-}
-
-static inline void __sg_mark_end(struct scatterlist *sg)
-{
+#ifdef CONFIG_DEBUG_SG
+ BUG_ON(sg->sg_magic != SG_MAGIC);
+#endif
+ /*
+ * Set termination bit, clear potential chain bit
+ */
sg->page_link |= 0x02;
+ sg->page_link &= ~0x01;
}
/**
@@ -218,7 +220,6 @@
static inline void sg_init_table(struct scatterlist *sgl, unsigned int nents)
{
memset(sgl, 0, sizeof(*sgl) * nents);
- sg_mark_end(sgl, nents);
#ifdef CONFIG_DEBUG_SG
{
unsigned int i;
@@ -226,6 +227,7 @@
sgl[i].sg_magic = SG_MAGIC;
}
#endif
+ sg_mark_end(&sgl[nents - 1]);
}
/**
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 64b50ff..32d5826 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2095,7 +2095,7 @@
{
int nsg = __skb_to_sgvec(skb, sg, offset, len);
- __sg_mark_end(&sg[nsg - 1]);
+ sg_mark_end(&sg[nsg - 1]);
return nsg;
}
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index eec02b2..d438dfb 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1083,7 +1083,7 @@
sg_set_buf(&sg[block++], key->key, key->keylen);
nbytes += key->keylen;
- __sg_mark_end(&sg[block - 1]);
+ sg_mark_end(&sg[block - 1]);
/* Now store the Hash into the packet */
err = crypto_hash_init(desc);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 4b90328..06be2a1 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -781,7 +781,7 @@
sg_set_buf(&sg[block++], key->key, key->keylen);
nbytes += key->keylen;
- __sg_mark_end(&sg[block - 1]);
+ sg_mark_end(&sg[block - 1]);
/* Now store the hash into the packet */
err = crypto_hash_init(desc);
diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c
index c387cf6..e09a95a 100644
--- a/net/rxrpc/rxkad.c
+++ b/net/rxrpc/rxkad.c
@@ -702,7 +702,7 @@
nsg++;
}
- __sg_mark_end(&sg[nsg - 1]);
+ sg_mark_end(&sg[nsg - 1]);
ASSERTCMP(sg[0].length + sg[1].length, ==, buflen);
}
diff --git a/net/sunrpc/auth_gss/gss_krb5_crypto.c b/net/sunrpc/auth_gss/gss_krb5_crypto.c
index ab7cbd6..0dd7923 100644
--- a/net/sunrpc/auth_gss/gss_krb5_crypto.c
+++ b/net/sunrpc/auth_gss/gss_krb5_crypto.c
@@ -211,8 +211,8 @@
if (thislen == 0)
return 0;
- __sg_mark_end(&desc->infrags[desc->fragno - 1]);
- __sg_mark_end(&desc->outfrags[desc->fragno - 1]);
+ sg_mark_end(&desc->infrags[desc->fragno - 1]);
+ sg_mark_end(&desc->outfrags[desc->fragno - 1]);
ret = crypto_blkcipher_encrypt_iv(&desc->desc, desc->outfrags,
desc->infrags, thislen);
@@ -293,7 +293,7 @@
if (thislen == 0)
return 0;
- __sg_mark_end(&desc->frags[desc->fragno - 1]);
+ sg_mark_end(&desc->frags[desc->fragno - 1]);
ret = crypto_blkcipher_decrypt_iv(&desc->desc, desc->frags,
desc->frags, thislen);
