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| author | Nicholas Bellinger <nab@linux-iscsi.org> | 2011-09-16 16:55:47 -0700 |
|---|---|---|
| committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2011-09-16 23:47:07 +0000 |
| commit | 40b054970afcf067896d62cd6f7e617c62665304 (patch) | |
| tree | 5596f2b4fa1c1f41f599caf21bd5d10681ab152b | |
| parent | 2ff017f5b4299e24a7f22d9a336dd162bf52bb54 (diff) | |
| download | kernel-common-40b054970afcf067896d62cd6f7e617c62665304.tar.gz kernel-common-40b054970afcf067896d62cd6f7e617c62665304.tar.bz2 kernel-common-40b054970afcf067896d62cd6f7e617c62665304.zip | |
iscsi-target: Fix sendpage breakage with proper padding+DataDigest iovec offsets
This patch fixes a bug in the iscsit_fe_sendpage_sg() transmit codepath that
was originally introduced with the v3.1 iscsi-target merge that incorrectly
uses hardcoded cmd->iov_data_count values to determine cmd->iov_data[] offsets
for extra outgoing padding and DataDigest payload vectors.
This code is obviously incorrect for the DataDigest enabled case with sendpage
offload, and this fix ensures correct operation for padding + DataDigest,
padding only, and DataDigest only cases. The bug was introduced during a
pre-merge change in iscsit_fe_sendpage_sg() to natively use struct scatterlist
instead of the legacy v3.0 struct se_mem logic.
Cc: Andy Grover <agrover@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
| -rw-r--r-- | drivers/target/iscsi/iscsi_target_util.c | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c index 1d1b4fe33e43..f00137f377b2 100644 --- a/drivers/target/iscsi/iscsi_target_util.c +++ b/drivers/target/iscsi/iscsi_target_util.c @@ -1256,7 +1256,7 @@ int iscsit_fe_sendpage_sg( struct kvec iov; u32 tx_hdr_size, data_len; u32 offset = cmd->first_data_sg_off; - int tx_sent; + int tx_sent, iov_off; send_hdr: tx_hdr_size = ISCSI_HDR_LEN; @@ -1276,9 +1276,19 @@ send_hdr: } data_len = cmd->tx_size - tx_hdr_size - cmd->padding; - if (conn->conn_ops->DataDigest) + /* + * Set iov_off used by padding and data digest tx_data() calls below + * in order to determine proper offset into cmd->iov_data[] + */ + if (conn->conn_ops->DataDigest) { data_len -= ISCSI_CRC_LEN; - + if (cmd->padding) + iov_off = (cmd->iov_data_count - 2); + else + iov_off = (cmd->iov_data_count - 1); + } else { + iov_off = (cmd->iov_data_count - 1); + } /* * Perform sendpage() for each page in the scatterlist */ @@ -1307,8 +1317,7 @@ send_pg: send_padding: if (cmd->padding) { - struct kvec *iov_p = - &cmd->iov_data[cmd->iov_data_count-1]; + struct kvec *iov_p = &cmd->iov_data[iov_off++]; tx_sent = tx_data(conn, iov_p, 1, cmd->padding); if (cmd->padding != tx_sent) { @@ -1322,8 +1331,7 @@ send_padding: send_datacrc: if (conn->conn_ops->DataDigest) { - struct kvec *iov_d = - &cmd->iov_data[cmd->iov_data_count]; + struct kvec *iov_d = &cmd->iov_data[iov_off]; tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN); if (ISCSI_CRC_LEN != tx_sent) { |