| Message ID | 2650722037cd756690f2e398468420bbaa26ed7f.1610170479.git.asml.silence@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | no-copy bvec | expand |
On Sat, Jan 09, 2021 at 04:03:00PM +0000, Pavel Begunkov wrote: > From: Christoph Hellwig <hch@lst.de> > > This saves one memory allocation, and ensures the bvecs aren't freed > before the AIO completion. This will allow the lower level code to be > optimized so that it can avoid allocating another bvec array. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> > --- > drivers/target/target_core_file.c | 20 ++++++-------------- > 1 file changed, 6 insertions(+), 14 deletions(-) > > diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c > index b0cb5b95e892..cce455929778 100644 > --- a/drivers/target/target_core_file.c > +++ b/drivers/target/target_core_file.c > @@ -241,6 +241,7 @@ struct target_core_file_cmd { > unsigned long len; > struct se_cmd *cmd; > struct kiocb iocb; > + struct bio_vec bvecs[]; > }; > > static void cmd_rw_aio_complete(struct kiocb *iocb, long ret, long ret2) > @@ -268,29 +269,22 @@ fd_execute_rw_aio(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, > struct target_core_file_cmd *aio_cmd; > struct iov_iter iter = {}; > struct scatterlist *sg; > - struct bio_vec *bvec; > ssize_t len = 0; > int ret = 0, i; > > - aio_cmd = kmalloc(sizeof(struct target_core_file_cmd), GFP_KERNEL); > + aio_cmd = kmalloc(struct_size(aio_cmd, bvecs, sgl_nents), GFP_KERNEL); > if (!aio_cmd) > return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; > > - bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL); > - if (!bvec) { > - kfree(aio_cmd); > - return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; > - } > - > for_each_sg(sgl, sg, sgl_nents, i) { > - bvec[i].bv_page = sg_page(sg); > - bvec[i].bv_len = sg->length; > - bvec[i].bv_offset = sg->offset; > + aio_cmd->bvecs[i].bv_page = sg_page(sg); > + aio_cmd->bvecs[i].bv_len = sg->length; > + aio_cmd->bvecs[i].bv_offset = sg->offset; > > len += sg->length; > } > > - iov_iter_bvec(&iter, is_write, bvec, sgl_nents, len); > + iov_iter_bvec(&iter, is_write, aio_cmd->bvecs, sgl_nents, len); > > aio_cmd->cmd = cmd; > aio_cmd->len = len; > @@ -307,8 +301,6 @@ fd_execute_rw_aio(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, > else > ret = call_read_iter(file, &aio_cmd->iocb, &iter); > > - kfree(bvec); > - > if (ret != -EIOCBQUEUED) > cmd_rw_aio_complete(&aio_cmd->iocb, ret, 0); > > -- > 2.24.0 > Reviewed-by: Ming Lei <ming.lei@redhat.com>
diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c index b0cb5b95e892..cce455929778 100644 --- a/drivers/target/target_core_file.c +++ b/drivers/target/target_core_file.c @@ -241,6 +241,7 @@ struct target_core_file_cmd { unsigned long len; struct se_cmd *cmd; struct kiocb iocb; + struct bio_vec bvecs[]; }; static void cmd_rw_aio_complete(struct kiocb *iocb, long ret, long ret2) @@ -268,29 +269,22 @@ fd_execute_rw_aio(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, struct target_core_file_cmd *aio_cmd; struct iov_iter iter = {}; struct scatterlist *sg; - struct bio_vec *bvec; ssize_t len = 0; int ret = 0, i; - aio_cmd = kmalloc(sizeof(struct target_core_file_cmd), GFP_KERNEL); + aio_cmd = kmalloc(struct_size(aio_cmd, bvecs, sgl_nents), GFP_KERNEL); if (!aio_cmd) return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; - bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL); - if (!bvec) { - kfree(aio_cmd); - return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; - } - for_each_sg(sgl, sg, sgl_nents, i) { - bvec[i].bv_page = sg_page(sg); - bvec[i].bv_len = sg->length; - bvec[i].bv_offset = sg->offset; + aio_cmd->bvecs[i].bv_page = sg_page(sg); + aio_cmd->bvecs[i].bv_len = sg->length; + aio_cmd->bvecs[i].bv_offset = sg->offset; len += sg->length; } - iov_iter_bvec(&iter, is_write, bvec, sgl_nents, len); + iov_iter_bvec(&iter, is_write, aio_cmd->bvecs, sgl_nents, len); aio_cmd->cmd = cmd; aio_cmd->len = len; @@ -307,8 +301,6 @@ fd_execute_rw_aio(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, else ret = call_read_iter(file, &aio_cmd->iocb, &iter); - kfree(bvec); - if (ret != -EIOCBQUEUED) cmd_rw_aio_complete(&aio_cmd->iocb, ret, 0);