From f0f408c65fc606cb5a4dfce2f5b051519820d967 Mon Sep 17 00:00:00 2001 From: Amjad Alsharafi Date: Sat, 20 Jul 2024 18:13:30 +0800 Subject: [PATCH] vvfat: Fix bug in writing to middle of file Before this commit, the behavior when calling `commit_one_file` for example with `offset=0x2000` (second cluster), what will happen is that we won't fetch the next cluster from the fat, and instead use the first cluster for the read operation. This is due to off-by-one error here, where `i=0x2000 !< offset=0x2000`, thus not fetching the next cluster. Signed-off-by: Amjad Alsharafi Reviewed-by: Kevin Wolf Tested-by: Kevin Wolf Message-ID: Signed-off-by: Kevin Wolf (cherry picked from commit b881cf00c99e03bc8a3648581f97736ff275b18b) Signed-off-by: zhujun2 --- block/vvfat.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/block/vvfat.c b/block/vvfat.c index 5dacc6cfac..2d9c4ff6a4 100644 --- a/block/vvfat.c +++ b/block/vvfat.c @@ -2521,8 +2521,9 @@ static int commit_one_file(BDRVVVFATState* s, return -1; } - for (i = s->cluster_size; i < offset; i += s->cluster_size) + for (i = 0; i < offset; i += s->cluster_size) { c = modified_fat_get(s, c); + } fd = qemu_open_old(mapping->path, O_RDWR | O_CREAT | O_BINARY, 0666); if (fd < 0) { -- 2.41.0.windows.1