From a6a0a7fb0e327d17594c971b4a39de14e025b415 Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Fri, 9 May 2025 15:40:19 -0500 Subject: [PATCH] file-posix, gluster: Handle zero block status hint better Although the previous patch to change 'bool want_zero' into a bitmask made no semantic change, it is now time to differentiate. When the caller specifically wants to know what parts of the file read as zero, we need to use lseek and actually reporting holes, rather than short-circuiting and advertising full allocation. This change will be utilized in later patches to let mirroring optimize for the case when the destination already reads as zeroes. Signed-off-by: Eric Blake Reviewed-by: Stefan Hajnoczi Message-ID: <20250509204341.3553601-17-eblake@redhat.com> --- block/file-posix.c | 3 ++- block/gluster.c | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/block/file-posix.c b/block/file-posix.c index 805a1a2949..ec95b74869 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -3289,7 +3289,8 @@ static int coroutine_fn raw_co_block_status(BlockDriverState *bs, return ret; } - if (mode != BDRV_WANT_PRECISE) { + if (!(mode & BDRV_WANT_ZERO)) { + /* There is no backing file - all bytes are allocated in this file. */ *pnum = bytes; *map = offset; *file = bs; diff --git a/block/gluster.c b/block/gluster.c index 1a2ef53e9b..89abd40f31 100644 --- a/block/gluster.c +++ b/block/gluster.c @@ -1478,7 +1478,7 @@ static int coroutine_fn qemu_gluster_co_block_status(BlockDriverState *bs, return ret; } - if (mode != BDRV_WANT_PRECISE) { + if (!(mode & BDRV_WANT_ZERO)) { *pnum = bytes; *map = offset; *file = bs; -- 2.39.5