Hi Christoph,
On Tue, 2014-06-10 at 17:53 +0200, Christophe Vu-Brugier wrote:
> A similar check is performed at the end of sbc_parse_cdb() and is now
> enforced if the SYNCHRONIZE CACHE command has a non zero logical block
> address or number of blocks.
>
> Signed-off-by: Christophe Vu-Brugier <cvubrugier@xxxxxxxx>
> ---
> I think that the check performed in sbc_check_valid_sectors() was
> wrong because it used cmd->data_length instead of using the number of
> sectors from the CDB.
>
> drivers/target/target_core_sbc.c | 47 ++++++++--------------------------------
> 1 file changed, 9 insertions(+), 38 deletions(-)
>
> diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
> index e022959..aaec147 100644
> --- a/drivers/target/target_core_sbc.c
> +++ b/drivers/target/target_core_sbc.c
> @@ -176,24 +176,6 @@ static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
> return cmd->se_dev->dev_attrib.block_size * sectors;
> }
>
> -static int sbc_check_valid_sectors(struct se_cmd *cmd)
> -{
> - struct se_device *dev = cmd->se_dev;
> - unsigned long long end_lba;
> - u32 sectors;
> -
> - sectors = cmd->data_length / dev->dev_attrib.block_size;
> - end_lba = dev->transport->get_blocks(dev) + 1;
> -
> - if (cmd->t_task_lba + sectors > end_lba) {
> - pr_err("target: lba %llu, sectors %u exceeds end lba %llu\n",
> - cmd->t_task_lba, sectors, end_lba);
> - return -EINVAL;
> - }
> -
> - return 0;
> -}
> -
> static inline u32 transport_get_sectors_6(unsigned char *cdb)
> {
> /*
> @@ -680,6 +662,7 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
> unsigned int size;
> u32 sectors = 0;
> sense_reason_t ret;
> + bool lba_check = false;
>
> switch (cdb[0]) {
> case READ_6:
> @@ -877,15 +860,6 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
> break;
> case SYNCHRONIZE_CACHE:
> case SYNCHRONIZE_CACHE_16:
> - if (!ops->execute_sync_cache) {
> - size = 0;
> - cmd->execute_cmd = sbc_emulate_noop;
> - break;
> - }
> -
> - /*
> - * Extract LBA and range to be flushed for emulated SYNCHRONIZE_CACHE
> - */
> if (cdb[0] == SYNCHRONIZE_CACHE) {
> sectors = transport_get_sectors_10(cdb);
> cmd->t_task_lba = transport_lba_32(cdb);
> @@ -893,18 +867,15 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
> sectors = transport_get_sectors_16(cdb);
> cmd->t_task_lba = transport_lba_64(cdb);
> }
> -
> size = sbc_get_size(cmd, sectors);
> -
> - /*
> - * Check to ensure that LBA + Range does not exceed past end of
> - * device for IBLOCK and FILEIO ->do_sync_cache() backend calls
> - */
> - if (cmd->t_task_lba || sectors) {
> - if (sbc_check_valid_sectors(cmd) < 0)
> - return TCM_ADDRESS_OUT_OF_RANGE;
> + if (cmd->t_task_lba || sectors)
> + lba_check = true;
> + if (ops->execute_sync_cache)
> + cmd->execute_cmd = ops->execute_sync_cache;
> + else {
> + size = 0;
> + cmd->execute_cmd = sbc_emulate_noop;
> }
> - cmd->execute_cmd = ops->execute_sync_cache;
> break;
> case UNMAP:
> if (!ops->execute_unmap)
> @@ -971,7 +942,7 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
> if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) && !cmd->execute_cmd)
> return TCM_UNSUPPORTED_SCSI_OPCODE;
>
> - if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
> + if ((cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) || lba_check) {
> unsigned long long end_lba;
>
> if (sectors > dev->dev_attrib.fabric_max_sectors) {
So one potential issue here..
Now that lba_check = true is set for SYNCHRONIZE_CACHE and causes the
fabric_max_sectors + hw_max_sectors checks to kick in from above, it's
possible for a SYNCHRONIZE_CACHE to fail when the sector size exceeds
these *_max_sectors checks.
IIRC, this is why these checks where separate to begin with..
So instead of adding lba_check, how about adding a goto to jump to the
shared end_lba check, bypassing the two _*max_sectors checks..?
Here is an updated version of your original patch that is being applied
to target-pending/for-next now.
Please review.
--nab
>From d1794cacd8b35fe91050de6edb0b61329a61b059 Mon Sep 17 00:00:00 2001
From: Christophe Vu-Brugier <cvubrugier@xxxxxxxx>
Date: Tue, 10 Jun 2014 17:53:21 +0200
Subject: [PATCH] target/sbc: Remove sbc_check_valid_sectors()
A similar check is performed at the end of sbc_parse_cdb() and is now
enforced if the SYNCHRONIZE CACHE command's backend supports
->execute_sync_cache().
(Add check_lba goto to avoid *_max_sectors checks - nab)
Signed-off-by: Christophe Vu-Brugier <cvubrugier@xxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/target_core_sbc.c | 45 +++++---------------------------------
1 file changed, 6 insertions(+), 39 deletions(-)
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 06f8ecd..56dfec8 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -176,24 +176,6 @@ static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
return cmd->se_dev->dev_attrib.block_size * sectors;
}
-static int sbc_check_valid_sectors(struct se_cmd *cmd)
-{
- struct se_device *dev = cmd->se_dev;
- unsigned long long end_lba;
- u32 sectors;
-
- sectors = cmd->data_length / dev->dev_attrib.block_size;
- end_lba = dev->transport->get_blocks(dev) + 1;
-
- if (cmd->t_task_lba + sectors > end_lba) {
- pr_err("target: lba %llu, sectors %u exceeds end lba %llu\n",
- cmd->t_task_lba, sectors, end_lba);
- return -EINVAL;
- }
-
- return 0;
-}
-
static inline u32 transport_get_sectors_6(unsigned char *cdb)
{
/*
@@ -888,15 +870,6 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
break;
case SYNCHRONIZE_CACHE:
case SYNCHRONIZE_CACHE_16:
- if (!ops->execute_sync_cache) {
- size = 0;
- cmd->execute_cmd = sbc_emulate_noop;
- break;
- }
-
- /*
- * Extract LBA and range to be flushed for emulated SYNCHRONIZE_CACHE
- */
if (cdb[0] == SYNCHRONIZE_CACHE) {
sectors = transport_get_sectors_10(cdb);
cmd->t_task_lba = transport_lba_32(cdb);
@@ -904,18 +877,12 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
sectors = transport_get_sectors_16(cdb);
cmd->t_task_lba = transport_lba_64(cdb);
}
-
- size = sbc_get_size(cmd, sectors);
-
- /*
- * Check to ensure that LBA + Range does not exceed past end of
- * device for IBLOCK and FILEIO ->do_sync_cache() backend calls
- */
- if (cmd->t_task_lba || sectors) {
- if (sbc_check_valid_sectors(cmd) < 0)
- return TCM_ADDRESS_OUT_OF_RANGE;
+ if (ops->execute_sync_cache) {
+ cmd->execute_cmd = ops->execute_sync_cache;
+ goto check_lba;
}
- cmd->execute_cmd = ops->execute_sync_cache;
+ size = 0;
+ cmd->execute_cmd = sbc_emulate_noop;
break;
case UNMAP:
if (!ops->execute_unmap)
@@ -999,7 +966,7 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
dev->dev_attrib.hw_max_sectors);
return TCM_INVALID_CDB_FIELD;
}
-
+check_lba:
end_lba = dev->transport->get_blocks(dev) + 1;
if (cmd->t_task_lba + sectors > end_lba) {
pr_err("cmd exceeds last lba %llu "
--
1.7.10.4
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