On Tue, 29 May 2012 21:43:12 +1000
ronnie sahlberg <ronniesahlberg@xxxxxxxxx> wrote:
> Tomo,
>
> Please find attached a patch that adds support for the opcode
> GET_LBA_STATUS for thin-provisioned luns.
>
>
> This patch uses the new lseek() SEEK_DATA/SEEK_HOLE to find what is
> mapped and what is not on a sparse backend file.
> These two new features are very new and only available on very recent
> linux kernels and select filesystems.
>
>
> Linux 3.2 and BTRFS (mint13 for example) support these two new seek types.
> If SEEK_DATA/SEEK_HOLE is not available we emulate these as always
> returning that the specified offset is mapped, and that the next
> "hole" is at end-of-file, i.e. as if the file was not sparse at all.
>
>>From abd7df828a2b7ac6146a2e315138719a7f9f193f Mon Sep 17 00:00:00 2001
> From: Ronnie Sahlberg <ronniesahlberg@xxxxxxxxx>
> Date: Tue, 29 May 2012 21:16:37 +1000
> Subject: [PATCH] SBC: Add GET_LBA_STATUS support
>
> Signed-off-by: Ronnie Sahlberg <ronniesahlberg@xxxxxxxxx>
> ---
> usr/sbc.c | 108 +++++++++++++++++++++++++++++++++++++++++++++++++----------
> usr/scsi.h | 1 +
> 2 files changed, 90 insertions(+), 19 deletions(-)
>
> diff --git a/usr/sbc.c b/usr/sbc.c
> index cf2b609..b7eaab0 100644
> --- a/usr/sbc.c
> +++ b/usr/sbc.c
> @@ -23,6 +23,9 @@
> * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
> * 02110-1301 USA
> */
> +#define _FILE_OFFSET_BITS 64
> +#define __USE_GNU
> +
> #include <errno.h>
> #include <stdio.h>
> #include <stdlib.h>
> @@ -30,6 +33,7 @@
> #include <stdint.h>
> #include <unistd.h>
> #include <linux/fs.h>
> +#include <sys/types.h>
>
> #include "list.h"
> #include "util.h"
> @@ -45,6 +49,23 @@
>
> static unsigned int blk_shift = DEFAULT_BLK_SHIFT;
>
> +static off_t find_next_data(struct scsi_lu *dev, off_t offset)
> +{
> +#ifdef SEEK_DATA
> + return lseek(dev->fd, offset, SEEK_DATA);
> +#else
Why not use lseek64 like other places in tgt?
> + return offset;
> +#endif
> +}
> +static off_t find_next_hole(struct scsi_lu *dev, off_t offset)
> +{
> +#ifdef SEEK_HOLE
> + return lseek(dev->fd, offset, SEEK_HOLE);
> +#else
> + return dev->size;
> +#endif
> +}
> +
> static int sbc_mode_page_update(struct scsi_cmd *cmd, uint8_t *data, int *changed)
> {
> uint8_t pcode = data[0] & 0x3f;
> @@ -437,27 +458,76 @@ static int sbc_service_action(int host_no, struct scsi_cmd *cmd)
> goto sense;
> }
>
> - if (cmd->scb[1] != SAI_READ_CAPACITY_16)
> - goto sense;
> + if (cmd->scb[1] == SAI_READ_CAPACITY_16) {
> + if (scsi_get_in_length(cmd) < 12)
> + goto overflow;
>
> - if (scsi_get_in_length(cmd) < 12)
> - goto overflow;
> + len = min_t(int, len, scsi_get_in_length(cmd));
>
> - len = min_t(int, len, scsi_get_in_length(cmd));
> -
> - data = scsi_get_in_buffer(cmd);
> - memset(data, 0, len);
> -
> - bshift = cmd->dev->blk_shift;
> - size = cmd->dev->size >> bshift;
> -
> - *((uint64_t *)(data)) = __cpu_to_be64(size - 1);
> - data[2] = __cpu_to_be32(1UL << bshift);
> -
> - val = (cmd->dev->attrs.lbppbe << 16) | cmd->dev->attrs.la_lba;
> - if (cmd->dev->attrs.thinprovisioning)
> - val |= (3 << 14); /* set LBPME and LBPRZ */
> - data[3] = __cpu_to_be32(val);
> + data = scsi_get_in_buffer(cmd);
> + memset(data, 0, len);
> +
> + bshift = cmd->dev->blk_shift;
> + size = cmd->dev->size >> bshift;
> +
> + *((uint64_t *)(data)) = __cpu_to_be64(size - 1);
> + data[2] = __cpu_to_be32(1UL << bshift);
> +
> + val = (cmd->dev->attrs.lbppbe << 16) | cmd->dev->attrs.la_lba;
> + if (cmd->dev->attrs.thinprovisioning)
> + val |= (3 << 14); /* set LBPME and LBPRZ */
> + data[3] = __cpu_to_be32(val);
> + } else if (cmd->scb[1] == SAI_GET_LBA_STATUS) {
> + uint64_t offset;
> + uint32_t pdl;
> + int type;
> + char *buf;
> +
> + if (scsi_get_in_length(cmd) < 24)
> + goto overflow;
> +
> + len = scsi_get_in_length(cmd);
> + buf = scsi_get_in_buffer(cmd);
> + memset(buf, 0, len);
> +
> + offset = __be64_to_cpu(*(uint64_t *)&cmd->scb[2])
> + << cmd->dev->blk_shift;
> + pdl = 4;
> + *(uint32_t *)&buf[0] = __cpu_to_be32(pdl);
> +
> + type = 0;
> + while (len >= 4 + pdl + 16) {
> + off_t next_offset;
> +
> + *(uint32_t *)&buf[0] = __cpu_to_be32(pdl + 16);
> +
> + if (offset >= cmd->dev->size)
> + break;
> +
> + next_offset = (type == 0) ?
> + find_next_hole(cmd->dev, offset) :
> + find_next_data(cmd->dev, offset);
> + if (next_offset == offset) {
> + type = 1 - type;
> + continue;
> + }
> +
> + *(uint64_t *)&buf[4 + pdl + 0] =
> + __cpu_to_be64(offset
> + >> cmd->dev->blk_shift);
> + *(uint64_t *)&buf[4 + pdl + 8] =
> + __cpu_to_be32((next_offset - offset)
> + >> cmd->dev->blk_shift);
> + buf[4 + pdl + 12] = type;
> +
> + pdl += 16;
> + type = 1 - type;
> + offset = next_offset;
> + }
> + len = 4 + pdl;
> + } else {
> + goto sense;
> + }
>
> overflow:
> scsi_set_in_resid_by_actual(cmd, len);
> diff --git a/usr/scsi.h b/usr/scsi.h
> index 0a02c36..2b994f9 100644
> --- a/usr/scsi.h
> +++ b/usr/scsi.h
> @@ -80,6 +80,7 @@
> #define WRITE_SAME_16 0x93
> #define SERVICE_ACTION_IN 0x9e
> #define SAI_READ_CAPACITY_16 0x10
> +#define SAI_GET_LBA_STATUS 0x12
> #define REPORT_LUNS 0xa0
> #define MOVE_MEDIUM 0xa5
> #define EXCHANGE_MEDIUM 0xa6
> --
> 1.7.3.1
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