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[Qemu-block] [PATCH 3/3] block/ssh: Add basic .bdrv_truncate()
From: |
Max Reitz |
Subject: |
[Qemu-block] [PATCH 3/3] block/ssh: Add basic .bdrv_truncate() |
Date: |
Wed, 14 Feb 2018 21:49:15 +0100 |
libssh2 does not seem to offer real truncation support, so we can only
grow files -- but that is better than nothing.
Signed-off-by: Max Reitz <address@hidden>
---
block/ssh.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/block/ssh.c b/block/ssh.c
index ff8576f21e..c235eec255 100644
--- a/block/ssh.c
+++ b/block/ssh.c
@@ -1219,6 +1219,29 @@ static int64_t ssh_getlength(BlockDriverState *bs)
return length;
}
+static int ssh_truncate(BlockDriverState *bs, int64_t offset,
+ PreallocMode prealloc, Error **errp)
+{
+ BDRVSSHState *s = bs->opaque;
+
+ if (prealloc != PREALLOC_MODE_OFF) {
+ error_setg(errp, "Unsupported preallocation mode '%s'",
+ PreallocMode_str(prealloc));
+ return -ENOTSUP;
+ }
+
+ if (offset < s->attrs.filesize) {
+ error_setg(errp, "ssh driver does not support shrinking files");
+ return -ENOTSUP;
+ }
+
+ if (offset == s->attrs.filesize) {
+ return 0;
+ }
+
+ return ssh_grow_file(s, offset, errp);
+}
+
static BlockDriver bdrv_ssh = {
.format_name = "ssh",
.protocol_name = "ssh",
@@ -1231,6 +1254,7 @@ static BlockDriver bdrv_ssh = {
.bdrv_co_readv = ssh_co_readv,
.bdrv_co_writev = ssh_co_writev,
.bdrv_getlength = ssh_getlength,
+ .bdrv_truncate = ssh_truncate,
.bdrv_co_flush_to_disk = ssh_co_flush,
.create_opts = &ssh_create_opts,
};
--
2.14.3