| Message ID | 1428150268-30260-2-git-send-email-akinobu.mita@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 4/4/2015 3:24 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: Asias He <asias@redhat.com> > 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 > --- > 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 4d614c9..19c893d 100644 > --- a/drivers/target/target_core_rd.c > +++ b/drivers/target/target_core_rd.c > @@ -387,11 +387,12 @@ static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, bool is_write) > 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; > sense_reason_t (*dif_verify)(struct se_cmd *, sector_t, unsigned int, > unsigned int, struct scatterlist *, int) = > is_write ? sbc_dif_verify_write : sbc_dif_verify_read; > @@ -404,10 +405,40 @@ static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, bool is_write) > 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); I think it is safe to free prot_sg if you just make sure to initialize it to NULL at declaration time, no need for 'need_to_release'. -- 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
2015-04-05 19:10 GMT+09:00 Sagi Grimberg <sagig@dev.mellanox.co.il>: > On 4/4/2015 3:24 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: Asias He <asias@redhat.com> >> 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 >> --- >> 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 4d614c9..19c893d 100644 >> --- a/drivers/target/target_core_rd.c >> +++ b/drivers/target/target_core_rd.c >> @@ -387,11 +387,12 @@ static sense_reason_t rd_do_prot_rw(struct se_cmd >> *cmd, bool is_write) >> 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; >> sense_reason_t (*dif_verify)(struct se_cmd *, sector_t, unsigned >> int, >> unsigned int, struct scatterlist *, int) = >> is_write ? sbc_dif_verify_write : sbc_dif_verify_read; >> @@ -404,10 +405,40 @@ static sense_reason_t rd_do_prot_rw(struct se_cmd >> *cmd, bool is_write) >> 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); > > > I think it is safe to free prot_sg if you just make sure to initialize > it to NULL at declaration time, no need for 'need_to_release'. 'need_to_release' is required to avoid kfree when 'prot_sg' is initialized to a pointer in the real prot space (i.e. "else" case above). -- 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 4d614c9..19c893d 100644 --- a/drivers/target/target_core_rd.c +++ b/drivers/target/target_core_rd.c @@ -387,11 +387,12 @@ static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, bool is_write) 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; sense_reason_t (*dif_verify)(struct se_cmd *, sector_t, unsigned int, unsigned int, struct scatterlist *, int) = is_write ? sbc_dif_verify_write : sbc_dif_verify_read; @@ -404,10 +405,40 @@ static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, bool is_write) 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: Asias He <asias@redhat.com> 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 --- drivers/target/target_core_rd.c | 39 +++++++++++++++++++++++++++++++++++---- 1 file changed, 35 insertions(+), 4 deletions(-)