lkml.org 
[lkml]   [2021]   [Jan]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v3 4/7] target/file: allocate the bvec array as part of struct target_core_file_cmd
Date
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
\
 
 \ /
  Last update: 2021-01-09 17:10    [W:0.078 / U:0.912 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site