| Message ID | 1428245979-5432-2-git-send-email-akinobu.mita@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 4/5/2015 5:59 PM, Akinobu Mita wrote: > The scatterlist for protection information which is passed to > sbc_dif_verify_read() or sbc_dif_verify_write() requires that > neighboring scatterlist entries are contiguous or chained so that they > can be iterated by sg_next(). > > However, the protection information for RD-MCP backends could be located > in the multiple scatterlist arrays when the ramdisk space is too large. > So if the read/write request straddles this boundary, sbc_dif_verify_read() > or sbc_dif_verify_write() can't iterate all scatterlist entries. > > This fixes it by allocating temporary scatterlist if it is needed. > > Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> > Cc: Nicholas Bellinger <nab@linux-iscsi.org> > Cc: Sagi Grimberg <sagig@dev.mellanox.co.il> > Cc: "Martin K. Petersen" <martin.petersen@oracle.com> > Cc: Christoph Hellwig <hch@lst.de> > Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> > Cc: target-devel@vger.kernel.org > Cc: linux-scsi@vger.kernel.org > --- > * No change from v1 > > drivers/target/target_core_rd.c | 39 +++++++++++++++++++++++++++++++++++---- > 1 file changed, 35 insertions(+), 4 deletions(-) > > diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c > index ac5e8d2..6e25eaa 100644 > --- a/drivers/target/target_core_rd.c > +++ b/drivers/target/target_core_rd.c > @@ -390,11 +390,12 @@ static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, dif_verify dif_verify) > struct se_device *se_dev = cmd->se_dev; > struct rd_dev *dev = RD_DEV(se_dev); > struct rd_dev_sg_table *prot_table; > + bool need_to_release = false; > struct scatterlist *prot_sg; > u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size; > - u32 prot_offset, prot_page; > + u32 prot_offset, prot_page, prot_npages; > u64 tmp; > - sense_reason_t rc; > + sense_reason_t rc = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; > > tmp = cmd->t_task_lba * se_dev->prot_length; > prot_offset = do_div(tmp, PAGE_SIZE); > @@ -404,10 +405,40 @@ static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, dif_verify dif_verify) > if (!prot_table) > return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; > > - prot_sg = &prot_table->sg_table[prot_page - > - prot_table->page_start_offset]; > + prot_npages = DIV_ROUND_UP(prot_offset + sectors * se_dev->prot_length, > + PAGE_SIZE); > + > + /* prot pages straddles multiple scatterlist tables */ > + if (prot_table->page_end_offset < prot_page + prot_npages - 1) { > + int i; > + > + prot_sg = kcalloc(prot_npages, sizeof(*prot_sg), GFP_KERNEL); > + if (!prot_sg) > + return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; > + > + need_to_release = true; > + sg_init_table(prot_sg, prot_npages); > + > + for (i = 0; i < prot_npages; i++) { > + if (prot_page + i > prot_table->page_end_offset) { > + prot_table = rd_get_prot_table(dev, > + prot_page + i); > + if (!prot_table) > + goto out; > + sg_unmark_end(&prot_sg[i - 1]); > + } > + prot_sg[i] = prot_table->sg_table[prot_page + i - > + prot_table->page_start_offset]; > + } > + } else { > + prot_sg = &prot_table->sg_table[prot_page - > + prot_table->page_start_offset]; > + } > > rc = dif_verify(cmd, cmd->t_task_lba, sectors, 0, prot_sg, prot_offset); > +out: > + if (need_to_release) > + kfree(prot_sg); > > return rc; > } > Acked-by: Sagi Grimberg <sagig@mellanox.com> -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sun, 2015-04-05 at 23:59 +0900, Akinobu Mita wrote: > The scatterlist for protection information which is passed to > sbc_dif_verify_read() or sbc_dif_verify_write() requires that > neighboring scatterlist entries are contiguous or chained so that they > can be iterated by sg_next(). > > However, the protection information for RD-MCP backends could be located > in the multiple scatterlist arrays when the ramdisk space is too large. > So if the read/write request straddles this boundary, sbc_dif_verify_read() > or sbc_dif_verify_write() can't iterate all scatterlist entries. > > This fixes it by allocating temporary scatterlist if it is needed. > > Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> > Cc: Nicholas Bellinger <nab@linux-iscsi.org> > Cc: Sagi Grimberg <sagig@dev.mellanox.co.il> > Cc: "Martin K. Petersen" <martin.petersen@oracle.com> > Cc: Christoph Hellwig <hch@lst.de> > Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> > Cc: target-devel@vger.kernel.org > Cc: linux-scsi@vger.kernel.org > --- > * No change from v1 > > drivers/target/target_core_rd.c | 39 +++++++++++++++++++++++++++++++++++---- > 1 file changed, 35 insertions(+), 4 deletions(-) > > diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c > index ac5e8d2..6e25eaa 100644 > --- a/drivers/target/target_core_rd.c > +++ b/drivers/target/target_core_rd.c > @@ -390,11 +390,12 @@ static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, dif_verify dif_verify) > struct se_device *se_dev = cmd->se_dev; > struct rd_dev *dev = RD_DEV(se_dev); > struct rd_dev_sg_table *prot_table; > + bool need_to_release = false; > struct scatterlist *prot_sg; > u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size; > - u32 prot_offset, prot_page; > + u32 prot_offset, prot_page, prot_npages; > u64 tmp; > - sense_reason_t rc; > + sense_reason_t rc = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; > > tmp = cmd->t_task_lba * se_dev->prot_length; > prot_offset = do_div(tmp, PAGE_SIZE); > @@ -404,10 +405,40 @@ static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, dif_verify dif_verify) > if (!prot_table) > return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; > > - prot_sg = &prot_table->sg_table[prot_page - > - prot_table->page_start_offset]; > + prot_npages = DIV_ROUND_UP(prot_offset + sectors * se_dev->prot_length, > + PAGE_SIZE); > + > + /* prot pages straddles multiple scatterlist tables */ > + if (prot_table->page_end_offset < prot_page + prot_npages - 1) { > + int i; > + > + prot_sg = kcalloc(prot_npages, sizeof(*prot_sg), GFP_KERNEL); > + if (!prot_sg) > + return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; > + > + need_to_release = true; > + sg_init_table(prot_sg, prot_npages); > + > + for (i = 0; i < prot_npages; i++) { > + if (prot_page + i > prot_table->page_end_offset) { > + prot_table = rd_get_prot_table(dev, > + prot_page + i); > + if (!prot_table) > + goto out; > + sg_unmark_end(&prot_sg[i - 1]); > + } > + prot_sg[i] = prot_table->sg_table[prot_page + i - > + prot_table->page_start_offset]; > + } > + } else { > + prot_sg = &prot_table->sg_table[prot_page - > + prot_table->page_start_offset]; > + } > Mmm, how about just explicitly doing sg_link() at prot_table scatterlist creation time instead..? That would save the extra allocation above, and AFAICT make for simpler code. --nab -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
2015-04-08 14:13 GMT+09:00 Nicholas A. Bellinger <nab@linux-iscsi.org>: > On Sun, 2015-04-05 at 23:59 +0900, Akinobu Mita wrote: >> The scatterlist for protection information which is passed to >> sbc_dif_verify_read() or sbc_dif_verify_write() requires that >> neighboring scatterlist entries are contiguous or chained so that they >> can be iterated by sg_next(). >> >> However, the protection information for RD-MCP backends could be located >> in the multiple scatterlist arrays when the ramdisk space is too large. >> So if the read/write request straddles this boundary, sbc_dif_verify_read() >> or sbc_dif_verify_write() can't iterate all scatterlist entries. >> >> This fixes it by allocating temporary scatterlist if it is needed. >> >> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> >> Cc: Nicholas Bellinger <nab@linux-iscsi.org> >> Cc: Sagi Grimberg <sagig@dev.mellanox.co.il> >> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> >> Cc: Christoph Hellwig <hch@lst.de> >> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> >> Cc: target-devel@vger.kernel.org >> Cc: linux-scsi@vger.kernel.org >> --- >> * No change from v1 >> >> drivers/target/target_core_rd.c | 39 +++++++++++++++++++++++++++++++++++---- >> 1 file changed, 35 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c >> index ac5e8d2..6e25eaa 100644 >> --- a/drivers/target/target_core_rd.c >> +++ b/drivers/target/target_core_rd.c >> @@ -390,11 +390,12 @@ static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, dif_verify dif_verify) >> struct se_device *se_dev = cmd->se_dev; >> struct rd_dev *dev = RD_DEV(se_dev); >> struct rd_dev_sg_table *prot_table; >> + bool need_to_release = false; >> struct scatterlist *prot_sg; >> u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size; >> - u32 prot_offset, prot_page; >> + u32 prot_offset, prot_page, prot_npages; >> u64 tmp; >> - sense_reason_t rc; >> + sense_reason_t rc = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; >> >> tmp = cmd->t_task_lba * se_dev->prot_length; >> prot_offset = do_div(tmp, PAGE_SIZE); >> @@ -404,10 +405,40 @@ static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, dif_verify dif_verify) >> if (!prot_table) >> return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; >> >> - prot_sg = &prot_table->sg_table[prot_page - >> - prot_table->page_start_offset]; >> + prot_npages = DIV_ROUND_UP(prot_offset + sectors * se_dev->prot_length, >> + PAGE_SIZE); >> + >> + /* prot pages straddles multiple scatterlist tables */ >> + if (prot_table->page_end_offset < prot_page + prot_npages - 1) { >> + int i; >> + >> + prot_sg = kcalloc(prot_npages, sizeof(*prot_sg), GFP_KERNEL); >> + if (!prot_sg) >> + return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; >> + >> + need_to_release = true; >> + sg_init_table(prot_sg, prot_npages); >> + >> + for (i = 0; i < prot_npages; i++) { >> + if (prot_page + i > prot_table->page_end_offset) { >> + prot_table = rd_get_prot_table(dev, >> + prot_page + i); >> + if (!prot_table) >> + goto out; >> + sg_unmark_end(&prot_sg[i - 1]); >> + } >> + prot_sg[i] = prot_table->sg_table[prot_page + i - >> + prot_table->page_start_offset]; >> + } >> + } else { >> + prot_sg = &prot_table->sg_table[prot_page - >> + prot_table->page_start_offset]; >> + } >> > > Mmm, how about just explicitly doing sg_link() at prot_table scatterlist > creation time instead..? Yeap, that would be an optimal solution. But some architectures don't support sg chaining (i.e. !CONFIG_ARCH_HAS_SG_CHAIN). > That would save the extra allocation above, and AFAICT make for simpler > code. Do you prefer fixing it conditionally with using #ifdef ? (i.e. sg chaining at creating time if CONFIG_ARCH_HAS_SG_CHAIN is defined, otherwise do the extra allocation above) If so, I'll resubmit the patch with such changes. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, 2015-04-08 at 23:25 +0900, Akinobu Mita wrote: > 2015-04-08 14:13 GMT+09:00 Nicholas A. Bellinger <nab@linux-iscsi.org>: > > On Sun, 2015-04-05 at 23:59 +0900, Akinobu Mita wrote: > >> The scatterlist for protection information which is passed to > >> sbc_dif_verify_read() or sbc_dif_verify_write() requires that > >> neighboring scatterlist entries are contiguous or chained so that they > >> can be iterated by sg_next(). > >> > >> However, the protection information for RD-MCP backends could be located > >> in the multiple scatterlist arrays when the ramdisk space is too large. > >> So if the read/write request straddles this boundary, sbc_dif_verify_read() > >> or sbc_dif_verify_write() can't iterate all scatterlist entries. > >> > >> This fixes it by allocating temporary scatterlist if it is needed. > >> > >> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> > >> Cc: Nicholas Bellinger <nab@linux-iscsi.org> > >> Cc: Sagi Grimberg <sagig@dev.mellanox.co.il> > >> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> > >> Cc: Christoph Hellwig <hch@lst.de> > >> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> > >> Cc: target-devel@vger.kernel.org > >> Cc: linux-scsi@vger.kernel.org > >> --- > >> * No change from v1 > >> > >> drivers/target/target_core_rd.c | 39 +++++++++++++++++++++++++++++++++++---- > >> 1 file changed, 35 insertions(+), 4 deletions(-) > >> > >> diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c > >> index ac5e8d2..6e25eaa 100644 > >> --- a/drivers/target/target_core_rd.c > >> +++ b/drivers/target/target_core_rd.c > >> @@ -390,11 +390,12 @@ static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, dif_verify dif_verify) > >> struct se_device *se_dev = cmd->se_dev; > >> struct rd_dev *dev = RD_DEV(se_dev); > >> struct rd_dev_sg_table *prot_table; > >> + bool need_to_release = false; > >> struct scatterlist *prot_sg; > >> u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size; > >> - u32 prot_offset, prot_page; > >> + u32 prot_offset, prot_page, prot_npages; > >> u64 tmp; > >> - sense_reason_t rc; > >> + sense_reason_t rc = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; > >> > >> tmp = cmd->t_task_lba * se_dev->prot_length; > >> prot_offset = do_div(tmp, PAGE_SIZE); > >> @@ -404,10 +405,40 @@ static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, dif_verify dif_verify) > >> if (!prot_table) > >> return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; > >> > >> - prot_sg = &prot_table->sg_table[prot_page - > >> - prot_table->page_start_offset]; > >> + prot_npages = DIV_ROUND_UP(prot_offset + sectors * se_dev->prot_length, > >> + PAGE_SIZE); > >> + > >> + /* prot pages straddles multiple scatterlist tables */ > >> + if (prot_table->page_end_offset < prot_page + prot_npages - 1) { > >> + int i; > >> + > >> + prot_sg = kcalloc(prot_npages, sizeof(*prot_sg), GFP_KERNEL); > >> + if (!prot_sg) > >> + return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; > >> + > >> + need_to_release = true; > >> + sg_init_table(prot_sg, prot_npages); > >> + > >> + for (i = 0; i < prot_npages; i++) { > >> + if (prot_page + i > prot_table->page_end_offset) { > >> + prot_table = rd_get_prot_table(dev, > >> + prot_page + i); > >> + if (!prot_table) > >> + goto out; > >> + sg_unmark_end(&prot_sg[i - 1]); > >> + } > >> + prot_sg[i] = prot_table->sg_table[prot_page + i - > >> + prot_table->page_start_offset]; > >> + } > >> + } else { > >> + prot_sg = &prot_table->sg_table[prot_page - > >> + prot_table->page_start_offset]; > >> + } > >> > > > > Mmm, how about just explicitly doing sg_link() at prot_table scatterlist > > creation time instead..? > > Yeap, that would be an optimal solution. But some architectures don't > support sg chaining (i.e. !CONFIG_ARCH_HAS_SG_CHAIN). > > > That would save the extra allocation above, and AFAICT make for simpler > > code. > > Do you prefer fixing it conditionally with using #ifdef ? (i.e. > sg chaining at creating time if CONFIG_ARCH_HAS_SG_CHAIN is defined, > otherwise do the extra allocation above) If so, I'll resubmit the > patch with such changes. Yes please. It would be nice to use sg_link() for the typical case when available, as long as the #idefs aren't too ugly and limited to target_core_rd.c code. --nab -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c index ac5e8d2..6e25eaa 100644 --- a/drivers/target/target_core_rd.c +++ b/drivers/target/target_core_rd.c @@ -390,11 +390,12 @@ static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, dif_verify dif_verify) struct se_device *se_dev = cmd->se_dev; struct rd_dev *dev = RD_DEV(se_dev); struct rd_dev_sg_table *prot_table; + bool need_to_release = false; struct scatterlist *prot_sg; u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size; - u32 prot_offset, prot_page; + u32 prot_offset, prot_page, prot_npages; u64 tmp; - sense_reason_t rc; + sense_reason_t rc = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; tmp = cmd->t_task_lba * se_dev->prot_length; prot_offset = do_div(tmp, PAGE_SIZE); @@ -404,10 +405,40 @@ static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, dif_verify dif_verify) if (!prot_table) return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; - prot_sg = &prot_table->sg_table[prot_page - - prot_table->page_start_offset]; + prot_npages = DIV_ROUND_UP(prot_offset + sectors * se_dev->prot_length, + PAGE_SIZE); + + /* prot pages straddles multiple scatterlist tables */ + if (prot_table->page_end_offset < prot_page + prot_npages - 1) { + int i; + + prot_sg = kcalloc(prot_npages, sizeof(*prot_sg), GFP_KERNEL); + if (!prot_sg) + return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + + need_to_release = true; + sg_init_table(prot_sg, prot_npages); + + for (i = 0; i < prot_npages; i++) { + if (prot_page + i > prot_table->page_end_offset) { + prot_table = rd_get_prot_table(dev, + prot_page + i); + if (!prot_table) + goto out; + sg_unmark_end(&prot_sg[i - 1]); + } + prot_sg[i] = prot_table->sg_table[prot_page + i - + prot_table->page_start_offset]; + } + } else { + prot_sg = &prot_table->sg_table[prot_page - + prot_table->page_start_offset]; + } rc = dif_verify(cmd, cmd->t_task_lba, sectors, 0, prot_sg, prot_offset); +out: + if (need_to_release) + kfree(prot_sg); return rc; }
The scatterlist for protection information which is passed to sbc_dif_verify_read() or sbc_dif_verify_write() requires that neighboring scatterlist entries are contiguous or chained so that they can be iterated by sg_next(). However, the protection information for RD-MCP backends could be located in the multiple scatterlist arrays when the ramdisk space is too large. So if the read/write request straddles this boundary, sbc_dif_verify_read() or sbc_dif_verify_write() can't iterate all scatterlist entries. This fixes it by allocating temporary scatterlist if it is needed. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Nicholas Bellinger <nab@linux-iscsi.org> Cc: Sagi Grimberg <sagig@dev.mellanox.co.il> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Christoph Hellwig <hch@lst.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: target-devel@vger.kernel.org Cc: linux-scsi@vger.kernel.org --- * No change from v1 drivers/target/target_core_rd.c | 39 +++++++++++++++++++++++++++++++++++---- 1 file changed, 35 insertions(+), 4 deletions(-)