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[PATCH v12 09/14] block: modify the comment for BDRV_REQ_PREFETCH flag
From: |
Andrey Shinkevich |
Subject: |
[PATCH v12 09/14] block: modify the comment for BDRV_REQ_PREFETCH flag |
Date: |
Thu, 22 Oct 2020 21:13:38 +0300 |
Modify the comment for the flag BDRV_REQ_PREFETCH as we are going to
use it alone and pass it to the COR-filter driver for further
processing.
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
---
include/block/block.h | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/include/block/block.h b/include/block/block.h
index ae7612f..1b6742f 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -81,9 +81,11 @@ typedef enum {
BDRV_REQ_NO_FALLBACK = 0x100,
/*
- * BDRV_REQ_PREFETCH may be used only together with BDRV_REQ_COPY_ON_READ
- * on read request and means that caller doesn't really need data to be
- * written to qiov parameter which may be NULL.
+ * BDRV_REQ_PREFETCH makes sense only in the context of copy-on-read
+ * (i.e., together with the BDRV_REQ_COPY_ON_READ flag or when a COR
+ * filter is involved), in which case it signals that the COR operation
+ * need not read the data into memory (qiov) but only ensure they are
+ * copied to the top layer (i.e., that COR operation is done).
*/
BDRV_REQ_PREFETCH = 0x200,
/* Mask of valid flags */
--
1.8.3.1
- Re: [PATCH v12 11/14] copy-on-read: add support for read flags to COR-filter, (continued)
- [PATCH v12 14/14] block: apply COR-filter to block-stream jobs, Andrey Shinkevich, 2020/10/22
- [PATCH v12 01/14] copy-on-read: support preadv/pwritev_part functions, Andrey Shinkevich, 2020/10/22
- [PATCH v12 02/14] block: add insert/remove node functions, Andrey Shinkevich, 2020/10/22
- [PATCH v12 10/14] block: include supported_read_flags into BDS structure, Andrey Shinkevich, 2020/10/22
- [PATCH v12 09/14] block: modify the comment for BDRV_REQ_PREFETCH flag,
Andrey Shinkevich <=
- [PATCH v12 13/14] stream: skip filters when writing backing file name to QCOW2 header, Andrey Shinkevich, 2020/10/22
[PATCH v12 12/14] copy-on-read: skip non-guest reads if no copy needed, Andrey Shinkevich, 2020/10/22
[PATCH v12 08/14] iotests: add #310 to test bottom node in COR driver, Andrey Shinkevich, 2020/10/22