From: Zhang Yi Date: Thu, 19 Jun 2025 11:18:05 +0000 (+0800) Subject: block: add FALLOC_FL_WRITE_ZEROES support X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=912b6038fe5c985fac06285f8019fd74cab67e81;p=thirdparty%2Fkernel%2Fstable.git block: add FALLOC_FL_WRITE_ZEROES support Add support for FALLOC_FL_WRITE_ZEROES, if the block device enables the unmap write zeroes operation, it will issue a write zeroes command. Signed-off-by: Zhang Yi Link: https://lore.kernel.org/20250619111806.3546162-9-yi.zhang@huaweicloud.com Reviewed-by: Christoph Hellwig Reviewed-by: "Martin K. Petersen" Signed-off-by: Christian Brauner --- diff --git a/block/fops.c b/block/fops.c index e1c921549d289..474656a0de70a 100644 --- a/block/fops.c +++ b/block/fops.c @@ -841,7 +841,7 @@ reexpand: #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) @@ -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 ((mode & FALLOC_FL_WRITE_ZEROES) && + !bdev_write_zeroes_unmap_sectors(bdev)) + return -EOPNOTSUPP; /* Don't go off the end of the device. */ isize = bdev_nr_bytes(bdev); @@ -886,6 +893,9 @@ 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;