From: Zhang Yi <yi.zh...@huawei.com>
Add support for FALLOC_FL_WRITE_ZEROES. It directly calls
blkdev_issue_zeroout() with flags set to 0. The underlying process will
attempt to use the fastest method for issuing zeroes. First, the block
layer will try to issue a write zeroes command if the storage device
supports it; if not, it will fall back to issuing zeroed data. Then, the
storage device driver may attempt to submit an unmap write zero command
if the device supports it; if not, the driver may fall back to
submitting a no-unmap write zeroes command.
Signed-off-by: Zhang Yi <yi.zh...@huawei.com>
---
block/fops.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/block/fops.c b/block/fops.c
index 77a5465309e7..e590c8997689 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -803,7 +803,7 @@ static ssize_t blkdev_read_iter(struct kiocb *iocb, struct
iov_iter *to)
#define BLKDEV_FALLOC_FL_SUPPORTED
\
(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \
- FALLOC_FL_ZERO_RANGE)
+ FALLOC_FL_ZERO_RANGE | FALLOC_FL_WRITE_ZEROES)
static long blkdev_fallocate(struct file *file, int mode, loff_t start,
loff_t len)
@@ -847,6 +847,9 @@ static long blkdev_fallocate(struct file *file, int mode,
loff_t start,
case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE:
flags = BLKDEV_ZERO_NOFALLBACK;
break;
+ case FALLOC_FL_WRITE_ZEROES:
+ flags = 0;
+ break;
default:
error = -EOPNOTSUPP;
goto fail;
--
2.46.1
