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| author | Varun Prakash <varun@chelsio.com> | 2017-07-29 18:31:49 +0300 |
|---|---|---|
| committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2017-07-31 01:35:34 +0300 |
| commit | d96adb9b076a12d30500347e2e667689062f44a0 (patch) | |
| tree | f9c294b8c5824a197899a712869eb425a1c8c688 /drivers/target | |
| parent | 310d40a973c560a24c79f84cb5f16dc540a05686 (diff) | |
| download | linux-d96adb9b076a12d30500347e2e667689062f44a0.tar.xz | |
cxgbit: fix sg_nents calculation
The current logic of calculating sg_nents can fail
if data_offset % PAGE_SIZE is not zero.
For example -
PAGE_SIZE = 4096
data_len = 3072
data_offset = 3072
As per current logic
sg_nents = max(1UL, DIV_ROUND_UP(data_len, PAGE_SIZE));
sg_nents = max(1UL, DIV_ROUND_UP(3072, 4096));
sg_nents = 1
But as data_offset % PAGE_SIZE = 3072 we should skip 3072 bytes
skip = 3K
sg_nents = max(1UL, DIV_ROUND_UP(3K(skip) + 3K(data_len), 4K(PAGE_SIZE));
sg_nents = 2;
This patch fixes this issue by adding skip to data_len.
Signed-off-by: Varun Prakash <varun@chelsio.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target')
| -rw-r--r-- | drivers/target/iscsi/cxgbit/cxgbit_target.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/target/iscsi/cxgbit/cxgbit_target.c b/drivers/target/iscsi/cxgbit/cxgbit_target.c index dda13f1af38e..514986b57c2d 100644 --- a/drivers/target/iscsi/cxgbit/cxgbit_target.c +++ b/drivers/target/iscsi/cxgbit/cxgbit_target.c @@ -827,7 +827,7 @@ cxgbit_put_login_tx(struct iscsi_conn *conn, struct iscsi_login *login, static void cxgbit_skb_copy_to_sg(struct sk_buff *skb, struct scatterlist *sg, - unsigned int nents) + unsigned int nents, u32 skip) { struct skb_seq_state st; const u8 *buf; @@ -846,7 +846,7 @@ cxgbit_skb_copy_to_sg(struct sk_buff *skb, struct scatterlist *sg, } consumed += sg_pcopy_from_buffer(sg, nents, (void *)buf, - buf_len, consumed); + buf_len, skip + consumed); } } @@ -912,7 +912,7 @@ cxgbit_handle_immediate_data(struct iscsi_cmd *cmd, struct iscsi_scsi_req *hdr, struct scatterlist *sg = &cmd->se_cmd.t_data_sg[0]; u32 sg_nents = max(1UL, DIV_ROUND_UP(pdu_cb->dlen, PAGE_SIZE)); - cxgbit_skb_copy_to_sg(csk->skb, sg, sg_nents); + cxgbit_skb_copy_to_sg(csk->skb, sg, sg_nents, 0); } cmd->write_data_done += pdu_cb->dlen; @@ -1069,11 +1069,13 @@ static int cxgbit_handle_iscsi_dataout(struct cxgbit_sock *csk) cmd->se_cmd.data_length); if (!(pdu_cb->flags & PDUCBF_RX_DATA_DDPD)) { + u32 skip = data_offset % PAGE_SIZE; + sg_off = data_offset / PAGE_SIZE; sg_start = &cmd->se_cmd.t_data_sg[sg_off]; - sg_nents = max(1UL, DIV_ROUND_UP(data_len, PAGE_SIZE)); + sg_nents = max(1UL, DIV_ROUND_UP(skip + data_len, PAGE_SIZE)); - cxgbit_skb_copy_to_sg(csk->skb, sg_start, sg_nents); + cxgbit_skb_copy_to_sg(csk->skb, sg_start, sg_nents, skip); } check_payload: |