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vdisk_blockio: Make large COMPARE AND WRITE requests work for stacked block devices (merge r5811 from trunk)

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git-svn-id: http://svn.code.sf.net/p/scst/svn/branches/3.0.x@5813 d57e44dd-8a1f-0410-8b47-8ef2f437770f
This commit is contained in:
Bart Van Assche
2014-09-17 11:18:17 +00:00
parent 38f613c069
commit 51e9717728
1 changed files with 86 additions and 18 deletions
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scst/src/dev_handlers/scst_vdisk.c
+86 -18
View File
@@ -118,6 +118,9 @@ static struct scst_trace_log vdisk_local_trace_tbl[] = {
#define DEF_TST SCST_TST_1_SEP_TASK_SETS
#define DEF_TMF_ONLY 0
#define NO_CAW_LEN_LIM 0xff
#define DEF_CAW_LEN_LIM 0xfe
/*
* Since we can't control backstorage device's reordering, we have to always
* report unrestricted reordering.
@@ -200,6 +203,10 @@ struct scst_vdisk_dev {
uint8_t inq_vend_specific[MAX_INQ_VEND_SPECIFIC_LEN];
int inq_vend_specific_len;
/* Block limits INQUIRY parameters */
uint8_t caw_len_lim;
struct mutex caw_mutex;
struct scst_device *dev;
struct list_head vdev_list_entry;
@@ -3391,7 +3398,7 @@ static enum compl_status_e vdisk_exec_inquiry(struct vdisk_cmd_params *p)
buf[1] = 0xB0;
buf[3] = 0x3C;
buf[4] = 1; /* WSNZ set */
buf[5] = 0xFF; /* No MAXIMUM COMPARE AND WRITE LENGTH limit */
buf[5] = virt_dev->caw_len_lim;
/* Optimal transfer granuality is PAGE_SIZE */
put_unaligned_be16(max_t(int, PAGE_SIZE/dev->block_size, 1), &buf[6]);
@@ -5423,6 +5430,17 @@ static void blockio_end_sync_io(struct bio *bio, int error)
#endif
}
/**
* blockio_rw_sync() - read or write up to @len bytes from a block I/O device
*
* Returns:
* - A negative value if an error occurred.
* - Zero if len == 0.
* - A positive value <= len if I/O succeeded.
*
* Note:
* Increments *@loff with the number of bytes transferred upon success.
*/
static ssize_t blockio_rw_sync(struct scst_vdisk_dev *virt_dev, void *buf,
size_t len, loff_t *loff, unsigned rw)
{
@@ -5461,12 +5479,23 @@ static ssize_t blockio_rw_sync(struct scst_vdisk_dev *virt_dev, void *buf,
bytes = min_t(size_t, PAGE_SIZE - off, buf + len - p);
q = is_vmalloc ? vmalloc_to_page(p) : virt_to_page(p);
rc = bio_add_page(bio, q, bytes, off);
if (WARN_ON_ONCE(rc < bytes))
goto free;
if (rc < bytes) {
if (rc <= 0 && p == buf) {
goto free;
} else {
if (rc > 0)
p += rc;
break;
}
}
}
submit_bio(rw, bio);
wait_for_completion(&c);
ret = (unsigned long)bio->bi_private ? : len;
ret = (unsigned long)bio->bi_private;
if (likely(ret == 0)) {
ret = p - buf;
*loff += ret;
}
free:
bio_put(bio);
@@ -5475,6 +5504,7 @@ out:
return ret;
}
/* Note: Updates *@loff if reading succeeded. */
static ssize_t fileio_read_sync(struct file *fd, void *buf, size_t len,
loff_t *loff)
{
@@ -5499,6 +5529,7 @@ out:
return ret;
}
/* Note: Updates *@loff if writing succeeded. */
static ssize_t fileio_write_sync(struct file *fd, void *buf, size_t len,
loff_t *loff)
{
@@ -5523,26 +5554,46 @@ out:
return ret;
}
/* Note: Updates *@loff if reading succeeded except for NULLIO devices. */
static ssize_t vdev_read_sync(struct scst_vdisk_dev *virt_dev, void *buf,
size_t len, loff_t *loff)
{
if (virt_dev->nullio)
ssize_t read, res;
if (virt_dev->nullio) {
return len;
else if (virt_dev->blockio)
return blockio_rw_sync(virt_dev, buf, len, loff, READ_SYNC);
else
} else if (virt_dev->blockio) {
for (read = 0; read < len; read += res) {
res = blockio_rw_sync(virt_dev, buf + read, len - read,
loff, READ_SYNC);
if (res < 0)
return res;
}
return read;
} else {
return fileio_read_sync(virt_dev->fd, buf, len, loff);
}
}
/* Note: Updates *@loff if reading succeeded except for NULLIO devices. */
static ssize_t vdev_write_sync(struct scst_vdisk_dev *virt_dev, void *buf,
size_t len, loff_t *loff)
{
if (virt_dev->nullio)
ssize_t written, res;
if (virt_dev->nullio) {
return len;
else if (virt_dev->blockio)
return blockio_rw_sync(virt_dev, buf, len, loff, WRITE_SYNC);
else
} else if (virt_dev->blockio) {
for (written = 0; written < len; written += res) {
res = blockio_rw_sync(virt_dev, buf + written,
len - written, loff, WRITE_SYNC);
if (res < 0)
return res;
}
return written;
} else {
return fileio_write_sync(virt_dev->fd, buf, len, loff);
}
}
static enum compl_status_e vdev_exec_verify(struct vdisk_cmd_params *p)
@@ -5667,6 +5718,16 @@ static enum compl_status_e vdisk_exec_caw(struct vdisk_cmd_params *p)
if (data_len == 0)
goto out;
if (virt_dev->caw_len_lim != NO_CAW_LEN_LIM &&
(data_len > virt_dev->caw_len_lim << dev->block_shift)) {
PRINT_ERROR("COMPARE AND WRITE: data length %u exceeds"
" limit %u << %u = %u", data_len,
virt_dev->caw_len_lim, dev->block_shift,
virt_dev->caw_len_lim << dev->block_shift);
scst_set_invalid_field_in_cdb(cmd, 13, 0);
goto out;
}
length = scst_get_buf_full(cmd, &caw_buf);
read_buf = vmalloc(data_len);
if (length < 0 || !read_buf) {
@@ -5684,6 +5745,8 @@ static enum compl_status_e vdisk_exec_caw(struct vdisk_cmd_params *p)
goto out;
}
mutex_lock(&virt_dev->caw_mutex);
loff = p->loff;
read = vdev_read_sync(virt_dev, read_buf, data_len, &loff);
if (read < data_len) {
@@ -5694,7 +5757,7 @@ static enum compl_status_e vdisk_exec_caw(struct vdisk_cmd_params *p)
else
scst_set_cmd_error(cmd,
SCST_LOAD_SENSE(scst_sense_read_error));
goto out;
goto unlock;
}
if (memcmp(caw_buf, read_buf, data_len) != 0) {
@@ -5711,9 +5774,8 @@ static enum compl_status_e vdisk_exec_caw(struct vdisk_cmd_params *p)
* INFORMATION field.
*/
scst_set_cmd_error_and_inf(cmd,
SCST_LOAD_SENSE(scst_sense_miscompare_error),
p->loff + i);
goto out;
SCST_LOAD_SENSE(scst_sense_miscompare_error), i);
goto unlock;
}
loff = p->loff;
@@ -5727,12 +5789,15 @@ static enum compl_status_e vdisk_exec_caw(struct vdisk_cmd_params *p)
else
scst_set_cmd_error(cmd,
SCST_LOAD_SENSE(scst_sense_write_error));
goto out;
goto unlock;
}
if (p->fua)
vdisk_fsync(loff, scst_cmd_get_data_len(cmd), cmd->dev,
vdisk_fsync(p->loff, scst_cmd_get_data_len(cmd), cmd->dev,
cmd->cmd_gfp_mask, cmd, false);
unlock:
mutex_unlock(&virt_dev->caw_mutex);
out:
if (read_buf)
vfree(read_buf);
@@ -5938,6 +6003,8 @@ static int vdev_create(struct scst_dev_type *devt,
}
spin_lock_init(&virt_dev->flags_lock);
mutex_init(&virt_dev->caw_mutex);
virt_dev->vdev_devt = devt;
virt_dev->rd_only = DEF_RD_ONLY;
@@ -5946,6 +6013,7 @@ static int vdev_create(struct scst_dev_type *devt,
virt_dev->rotational = DEF_ROTATIONAL;
virt_dev->thin_provisioned = DEF_THIN_PROVISIONED;
virt_dev->tst = DEF_TST;
virt_dev->caw_len_lim = DEF_CAW_LEN_LIM;
virt_dev->blk_shift = DEF_DISK_BLOCK_SHIFT;