forge/linux-pinenote
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

IB/srp: add support for indirect tables that don't fit in SRP_CMD

Browse source 
This allows us to guarantee the ability to submit up to 8 MB requests
based on the current value of SCSI_MAX_SG_CHAIN_SEGMENTS. While FMR will
usually condense the requests into 8 SG entries, it is imperative that
the target support external tables in case the FMR mapping fails or is
not supported.

We add a safety valve to allow targets without the needed support to
reap the benefits of the large tables, but fail in a manner that lets
the user know that the data didn't make it to the device. The user must
add "allow_ext_sg=1" to the target parameters to indicate that the
target has the needed support.

If indirect_sg_entries is not specified in the modules options, then
the sg_tablesize for the target will default to cmd_sg_entries unless
overridden by the target options.

Signed-off-by: David Dillow <dillowda@ornl.gov>
This commit is contained in:
David Dillow 2011-01-16 13:57:10 -05:00
parent 8f26c9ff9c
commit c07d424d61
2 changed files with 110 additions and 12 deletions
Download patch file Download diff file Expand all files Collapse all files

5
drivers/infiniband/ulp/srp/ib_srp.h
View file

@ -117,6 +117,8 @@ struct srp_request {
struct srp_iu *cmd;
struct ib_pool_fmr **fmr_list;
u64 *map_page;
struct srp_direct_buf *indirect_desc;
dma_addr_t indirect_dma_addr;
short nfmr;
short index;
};
@ -137,6 +139,8 @@ struct srp_target_port {
enum srp_target_state state;
unsigned int max_iu_len;
unsigned int cmd_sg_cnt;
unsigned int indirect_size;
bool allow_ext_sg;
/* Everything above this point is used in the hot path of
* command processing. Try to keep them packed into cachelines.
@ -151,6 +155,7 @@ struct srp_target_port {
struct Scsi_Host *scsi_host;
char target_name[32];
unsigned int scsi_id;
unsigned int sg_tablesize;
struct ib_sa_path_rec path;
__be16 orig_dgid[8];