From: Zhang Yi <yi.zhang@xxxxxxxxxx> 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.zhang@xxxxxxxxxx> --- block/fops.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/block/fops.c b/block/fops.c index 13a67940d040..56486de0960b 100644 --- a/block/fops.c +++ b/block/fops.c @@ -777,7 +777,7 @@ 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) @@ -836,6 +836,15 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start, len >> SECTOR_SHIFT, GFP_KERNEL, BLKDEV_ZERO_NOFALLBACK); break; + case FALLOC_FL_WRITE_ZEROES: + error = truncate_bdev_range(bdev, file_to_blk_mode(file), start, end); + if (error) + goto fail; + + error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT, + len >> SECTOR_SHIFT, GFP_KERNEL, + 0); + break; default: error = -EOPNOTSUPP; } -- 2.39.2
