ivampiresp/Spdk
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

bdev/split: call get buffer function before forwarding read I/O to the base bdev

Browse Source 
iSCSI target does not allocate data buffer on read, and delegate
allocation to the bdev.

When the bdev is a split vbdev, the split vbdev does not allocate
data buffer and delegate allocation to the backend bdev.

In this case, iSCSI target expects the buffer is allocated until
notifying completion to the split vbdev. However, the split vbdev
notifies completion to the backend bdev when calling the callback
of iSCSI target. The backend bdev frees the buffer immediately,
but iSCSI target still uses the buffer. If the buffer is reused
by another I/O, data corruption will occur.

For this issue, vbdev_split_submti_request() calls
spdk_bdev_io_get_buf() when the I/O is read, and its callback
vbdev_split_get_buf_cb calls _vbdev_split_submit_request() then.

This will ensure the buffer is allocated before forwarding I/O
to the backed bdev.

Signed-off-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Change-Id: Icfd0663b548479ac0bf6b5b49420f144142e3300
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/461348
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
This commit is contained in:
Shuhei Matsumoto 2019-07-11 14:23:09 +09:00 committed by Changpeng Liu
parent 5f5a5d4a58
commit 25532d08f8
1 changed files with 28 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
lib/bdev/split/vbdev_split.c
View File

@ -83,7 +83,7 @@ static int vbdev_split_config_json(struct spdk_json_write_ctx *w);
static int vbdev_split_get_ctx_size(void); static int vbdev_split_get_ctx_size(void);
static void static void
vbdev_split_submit_request(struct spdk_io_channel *_ch, struct spdk_bdev_io *bdev_io); _vbdev_split_submit_request(struct spdk_io_channel *_ch, struct spdk_bdev_io *bdev_io);
static struct spdk_bdev_module split_if = { static struct spdk_bdev_module split_if = {
.name = "split", .name = "split",
@ -126,7 +126,7 @@ vbdev_split_resubmit_io(void *arg)
{ {
struct vbdev_split_bdev_io *split_io = (struct vbdev_split_bdev_io *)arg; struct vbdev_split_bdev_io *split_io = (struct vbdev_split_bdev_io *)arg;
vbdev_split_submit_request(split_io->ch, split_io->bdev_io); _vbdev_split_submit_request(split_io->ch, split_io->bdev_io);
} }
static void static void
@ -147,7 +147,7 @@ vbdev_split_queue_io(struct vbdev_split_bdev_io *split_io)
} }
static void static void
vbdev_split_submit_request(struct spdk_io_channel *_ch, struct spdk_bdev_io *bdev_io) _vbdev_split_submit_request(struct spdk_io_channel *_ch, struct spdk_bdev_io *bdev_io)
{ {
struct vbdev_split_channel *ch = spdk_io_channel_get_ctx(_ch); struct vbdev_split_channel *ch = spdk_io_channel_get_ctx(_ch);
struct vbdev_split_bdev_io *io_ctx = (struct vbdev_split_bdev_io *)bdev_io->driver_ctx; struct vbdev_split_bdev_io *io_ctx = (struct vbdev_split_bdev_io *)bdev_io->driver_ctx;
@ -167,6 +167,31 @@ vbdev_split_submit_request(struct spdk_io_channel *_ch, struct spdk_bdev_io *bde
} }
} }
static void
vbdev_split_get_buf_cb(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io, bool success)
{
if (!success) {
spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
return;
}
_vbdev_split_submit_request(ch, bdev_io);
}
static void
vbdev_split_submit_request(struct spdk_io_channel *_ch, struct spdk_bdev_io *bdev_io)
{
switch (bdev_io->type) {
case SPDK_BDEV_IO_TYPE_READ:
spdk_bdev_io_get_buf(bdev_io, vbdev_split_get_buf_cb,
bdev_io->u.bdev.num_blocks * bdev_io->bdev->blocklen);
break;
default:
_vbdev_split_submit_request(_ch, bdev_io);
break;
}
}
static int static int
vbdev_split_dump_info_json(void *ctx, struct spdk_json_write_ctx *w) vbdev_split_dump_info_json(void *ctx, struct spdk_json_write_ctx *w)
{ {