From fda94a9919fd632033979ad7765a99ae3cab9289 Mon Sep 17 00:00:00 2001 From: Eric Sandeen Date: Tue, 11 Feb 2025 14:14:21 -0600 Subject: [PATCH] exfat: short-circuit zero-byte writes in exfat_file_write_iter When generic_write_checks() returns zero, it means that iov_iter_count() is zero, and there is no work to do. Simply return success like all other filesystems do, rather than proceeding down the write path, which today yields an -EFAULT in generic_perform_write() via the (fault_in_iov_iter_readable(i, bytes) == bytes) check when bytes == 0. Fixes: 11a347fb6cef ("exfat: change to get file size from DataLength") Reported-by: Noah Signed-off-by: Eric Sandeen Reviewed-by: Yuezhang Mo Signed-off-by: Namjae Jeon --- fs/exfat/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/exfat/file.c b/fs/exfat/file.c index 05b51e721783..807349d8ea05 100644 --- a/fs/exfat/file.c +++ b/fs/exfat/file.c @@ -587,7 +587,7 @@ static ssize_t exfat_file_write_iter(struct kiocb *iocb, struct iov_iter *iter) valid_size = ei->valid_size; ret = generic_write_checks(iocb, iter); - if (ret < 0) + if (ret <= 0) goto unlock; if (iocb->ki_flags & IOCB_DIRECT) { -- 2.50.1