prepare_itcw() builds the FCX prefix block (PFX + LRE) for track-mode
I/O. Extend it to handle DASD_ECKD_CCW_WRITE_FULL_TRACK.
WRITE_FULL_TRACK needs two extra bytes appended to the LRE for that
bitmask. The prefix block is a scratch buffer copied into the TCCB by
itcw_add_dcw(), so keep it on the stack (sized for the two extra bytes)
rather than allocating it: this runs in the writeback path and must not
depend on an allocation that can fail under memory pressure.
Reviewed-by: Jan Höppner <hoeppner@linux.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
---
drivers/s390/block/dasd_eckd.c | 64 +++++++++++++++++++++++++++-------
1 file changed, 51 insertions(+), 13 deletions(-)
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index be54c356dc24..ae122fbdca3e 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -4388,11 +4388,13 @@ static int prepare_itcw(struct itcw *itcw,
unsigned int tlf,
unsigned int blk_per_trk)
{
- struct PFX_eckd_data pfxdata;
+ u8 pfxbuf[sizeof(struct PFX_eckd_data) + 2] __aligned(8);
+ struct PFX_eckd_data *pfxdata = (struct PFX_eckd_data *)pfxbuf;
struct dasd_eckd_private *basepriv, *startpriv;
struct DE_eckd_data *dedata;
struct LRE_eckd_data *lredata;
struct dcw *dcw;
+ int pfxsize;
u32 begcyl, endcyl;
u16 heads, beghead, endhead;@@ -4402,26 +4404,31 @@ static int prepare_itcw(struct itcw *itcw,
int sector = 0;
int dn, d;
+ pfxsize = sizeof(struct PFX_eckd_data);
+ /* prefix + LRE extended data */
+ if (cmd == DASD_ECKD_CCW_WRITE_FULL_TRACK)
+ pfxsize += 2;
+
+ memset(pfxbuf, 0, pfxsize);
/* setup prefix data */
basepriv = basedev->private;
startpriv = startdev->private;
- dedata = &pfxdata.define_extent;
- lredata = &pfxdata.locate_record;
+ dedata = &pfxdata->define_extent;
+ lredata = &pfxdata->locate_record;
- memset(&pfxdata, 0, sizeof(pfxdata));
- pfxdata.format = 1; /* PFX with LRE */
- pfxdata.base_address = basepriv->conf.ned->unit_addr;
- pfxdata.base_lss = basepriv->conf.ned->ID;
- pfxdata.validity.define_extent = 1;
+ pfxdata->format = 1; /* PFX with LRE */
+ pfxdata->base_address = basepriv->conf.ned->unit_addr;
+ pfxdata->base_lss = basepriv->conf.ned->ID;
+ pfxdata->validity.define_extent = 1;
/* private uid is kept up to date, conf_data may be outdated */
if (startpriv->uid.type == UA_BASE_PAV_ALIAS)
- pfxdata.validity.verify_base = 1;
+ pfxdata->validity.verify_base = 1;
if (startpriv->uid.type == UA_HYPER_PAV_ALIAS) {
- pfxdata.validity.verify_base = 1;
- pfxdata.validity.hyper_pav = 1;
+ pfxdata->validity.verify_base = 1;
+ pfxdata->validity.hyper_pav = 1;
}
switch (cmd) {@@ -4451,7 +4458,38 @@ static int prepare_itcw(struct itcw *itcw,
* data as well.
*/
if (dedata->ga_extended & 0x08 && dedata->ga_extended & 0x02)
- pfxdata.validity.time_stamp = 1; /* 'Time Stamp Valid' */
+ pfxdata->validity.time_stamp = 1; /* 'Time Stamp Valid' */
+ pfx_cmd = DASD_ECKD_CCW_PFX;
+ break;
+ case DASD_ECKD_CCW_WRITE_FULL_TRACK:
+ dedata->mask.perm = 0x3;
+ dedata->mask.auth = 0x00;
+ dedata->attributes.operation = basepriv->attrib.operation;
+ dedata->blk_size = blksize;
+ dedata->ga_extended |= 0x42;
+ rc = set_timestamp(NULL, dedata, basedev);
+ lredata->operation.orientation = 0x0;
+ lredata->operation.operation = 0x3F;
+ lredata->extended_operation = 0x11;
+ lredata->auxiliary.check_bytes = 0x2;
+ lredata->extended_parameter_length = 0x02;
+ if (count > 8) {
+ lredata->extended_parameter[0] = 0xFF;
+ lredata->extended_parameter[1] = 0xFF;
+ lredata->extended_parameter[1] <<= (16 - count);
+ } else {
+ lredata->extended_parameter[0] = 0xFF;
+ lredata->extended_parameter[0] <<= (8 - count);
+ lredata->extended_parameter[1] = 0x00;
+ }
+ sector = 0xFF;
+ /*
+ * If XRC is supported the System Time Stamp is set. The
+ * validity of the time stamp must be reflected in the prefix
+ * data as well.
+ */
+ if (dedata->ga_extended & 0x08 && dedata->ga_extended & 0x02)
+ pfxdata->validity.time_stamp = 1; /* 'Time Stamp Valid' */
pfx_cmd = DASD_ECKD_CCW_PFX;
break;
case DASD_ECKD_CCW_READ_COUNT_MT:@@ -4530,7 +4568,7 @@ static int prepare_itcw(struct itcw *itcw,
lredata->search_arg.record = rec_on_trk;
dcw = itcw_add_dcw(itcw, pfx_cmd, 0,
- &pfxdata, sizeof(pfxdata), total_data_size);
+ pfxdata, pfxsize, total_data_size);
return PTR_ERR_OR_ZERO(dcw);
}
--
2.53.0