Re: [PATCH 09/10] block: add FALLOC_FL_WRITE_ZEROES support
From: Christoph Hellwig <hch@lst.de>
Date: 2025-06-11 06:11:04
Also in:
dm-devel, linux-block, linux-fsdevel, linux-nvme, linux-scsi, linux-xfs, lkml
On Wed, Jun 04, 2025 at 10:08:49AM +0800, Zhang Yi wrote:
quoted hunk ↗ jump to hunk
@@ -856,6 +856,13 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start, /* Fail if we don't recognize the flags. */ if (mode & ~BLKDEV_FALLOC_FL_SUPPORTED) return -EOPNOTSUPP; + /* + * Don't allow writing zeroes if the device does not enable the + * unmap write zeroes operation. + */ + if (!bdev_write_zeroes_unmap(bdev) && + (mode & FALLOC_FL_WRITE_ZEROES))
Cosmetic nitpick, but I'd turn the check around to check the mode first as that's easier to read. The whole check also fits onto a single line: if ((mode & FALLOC_FL_WRITE_ZEROES) && !bdev_write_zeroes_unmap(bdev)) Otherwise looks good: Reviewed-by: Christoph Hellwig <hch@lst.de>