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author | Shlomo Pongratz <shlomop@mellanox.com> | 2014-02-07 00:41:37 -0600 |
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committer | James Bottomley <JBottomley@Parallels.com> | 2014-03-15 10:19:18 -0700 |
commit | 5d0fddd0a72d3023bb0fa97e546f687aa6222be3 (patch) | |
tree | a08201b0fcf76e1efcf1be3741b5972be146c341 | |
parent | ac0245ff80942e33458cf32926dc1177239f4e19 (diff) | |
download | talos-op-linux-5d0fddd0a72d3023bb0fa97e546f687aa6222be3.tar.gz talos-op-linux-5d0fddd0a72d3023bb0fa97e546f687aa6222be3.zip |
[SCSI] libiscsi: Restructure iscsi_tcp r2t response logic
Restructure the iscsi_tcp_r2t_rsp routine in order to avoid allocating
r2t from r2tpool.queue and returning it back in case the parameters
rhdr->data_length and or rhdr->data_offset prohibit the requing.
Since the values of these parameters are known prior to the allocation,
we can pre-check and thus avoid futile allocations.
[jejb: checkpatch fixes]
Signed-off-by: Shlomo Pongratz <shlomop@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
-rw-r--r-- | drivers/scsi/libiscsi_tcp.c | 43 |
1 files changed, 22 insertions, 21 deletions
diff --git a/drivers/scsi/libiscsi_tcp.c b/drivers/scsi/libiscsi_tcp.c index 1d58d5336018..2f738dddd078 100644 --- a/drivers/scsi/libiscsi_tcp.c +++ b/drivers/scsi/libiscsi_tcp.c @@ -529,6 +529,8 @@ static int iscsi_tcp_r2t_rsp(struct iscsi_conn *conn, struct iscsi_task *task) struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr; struct iscsi_r2t_info *r2t; int r2tsn = be32_to_cpu(rhdr->r2tsn); + u32 data_length; + u32 data_offset; int rc; if (tcp_conn->in.datalen) { @@ -554,40 +556,39 @@ static int iscsi_tcp_r2t_rsp(struct iscsi_conn *conn, struct iscsi_task *task) return 0; } - rc = kfifo_out(&tcp_task->r2tpool.queue, (void*)&r2t, sizeof(void*)); - if (!rc) { - iscsi_conn_printk(KERN_ERR, conn, "Could not allocate R2T. " - "Target has sent more R2Ts than it " - "negotiated for or driver has leaked.\n"); - return ISCSI_ERR_PROTO; - } - - r2t->exp_statsn = rhdr->statsn; - r2t->data_length = be32_to_cpu(rhdr->data_length); - if (r2t->data_length == 0) { + data_length = be32_to_cpu(rhdr->data_length); + if (data_length == 0) { iscsi_conn_printk(KERN_ERR, conn, "invalid R2T with zero data len\n"); - kfifo_in(&tcp_task->r2tpool.queue, (void*)&r2t, - sizeof(void*)); return ISCSI_ERR_DATALEN; } - if (r2t->data_length > session->max_burst) + if (data_length > session->max_burst) ISCSI_DBG_TCP(conn, "invalid R2T with data len %u and max " "burst %u. Attempting to execute request.\n", - r2t->data_length, session->max_burst); + data_length, session->max_burst); - r2t->data_offset = be32_to_cpu(rhdr->data_offset); - if (r2t->data_offset + r2t->data_length > scsi_out(task->sc)->length) { + data_offset = be32_to_cpu(rhdr->data_offset); + if (data_offset + data_length > scsi_out(task->sc)->length) { iscsi_conn_printk(KERN_ERR, conn, "invalid R2T with data len %u at offset %u " - "and total length %d\n", r2t->data_length, - r2t->data_offset, scsi_out(task->sc)->length); - kfifo_in(&tcp_task->r2tpool.queue, (void*)&r2t, - sizeof(void*)); + "and total length %d\n", data_length, + data_offset, scsi_out(task->sc)->length); return ISCSI_ERR_DATALEN; } + rc = kfifo_out(&tcp_task->r2tpool.queue, (void *)&r2t, sizeof(void *)); + if (!rc) { + iscsi_conn_printk(KERN_ERR, conn, "Could not allocate R2T. " + "Target has sent more R2Ts than it " + "negotiated for or driver has leaked.\n"); + return ISCSI_ERR_PROTO; + } + + r2t->exp_statsn = rhdr->statsn; + r2t->data_length = data_length; + r2t->data_offset = data_offset; + r2t->ttt = rhdr->ttt; /* no flip */ r2t->datasn = 0; r2t->sent = 0; |