From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33102) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1elaFz-0007iT-1V for qemu-devel@nongnu.org; Tue, 13 Feb 2018 08:04:24 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1elaFw-0006cK-IN for qemu-devel@nongnu.org; Tue, 13 Feb 2018 08:04:23 -0500 From: Max Reitz Date: Tue, 13 Feb 2018 14:03:52 +0100 Message-Id: <20180213130356.8885-4-mreitz@redhat.com> In-Reply-To: <20180213130356.8885-1-mreitz@redhat.com> References: <20180213130356.8885-1-mreitz@redhat.com> Subject: [Qemu-devel] [PATCH 3/7] gluster: Query current size in do_truncate() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, Max Reitz , sheepdog@lists.wpkg.org, Kevin Wolf , Jeff Cody , Hitoshi Mitake , Liu Yuan Instead of expecting the current size to be 0, query it and allocate only the area [current_size, offset) if preallocation is requested. Signed-off-by: Max Reitz --- block/gluster.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/block/gluster.c b/block/gluster.c index 8178541416..806b894bc8 100644 --- a/block/gluster.c +++ b/block/gluster.c @@ -968,10 +968,27 @@ static coroutine_fn int qemu_gluster_co_pwrite_zeroes(BlockDriverState *bs, static int qemu_gluster_do_truncate(struct glfs_fd *fd, int64_t offset, PreallocMode prealloc, Error **errp) { + int64_t current_length; + + current_length = glfs_lseek(fd, 0, SEEK_END); + if (current_length < 0) { + error_setg_errno(errp, errno, "Failed to determine current size"); + return -errno; + } + + if (current_length > offset && prealloc != PREALLOC_MODE_OFF) { + error_setg(errp, "Cannot use preallocation for shrinking files"); + return -ENOTSUP; + } + + if (current_length == offset) { + return 0; + } + switch (prealloc) { #ifdef CONFIG_GLUSTERFS_FALLOCATE case PREALLOC_MODE_FALLOC: - if (glfs_fallocate(fd, 0, 0, offset)) { + if (glfs_fallocate(fd, 0, current_length, offset - current_length)) { error_setg_errno(errp, errno, "Could not preallocate data"); return -errno; } @@ -983,7 +1000,7 @@ static int qemu_gluster_do_truncate(struct glfs_fd *fd, int64_t offset, error_setg_errno(errp, errno, "Could not resize file"); return -errno; } - if (glfs_zerofill(fd, 0, offset)) { + if (glfs_zerofill(fd, current_length, offset - current_length)) { error_setg_errno(errp, errno, "Could not zerofill the new area"); return -errno; } -- 2.14.3