9pfs: remove side-effects in local_init()

If this function fails, it should not modify *ctx.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit 00c90bd1c2)
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
stable-2.8
Greg Kurz 2017-02-26 23:41:48 +01:00 committed by Michael Roth
parent 2c4f0f6c11
commit e103f9e7b4
1 changed files with 19 additions and 18 deletions

View File

@ -1169,9 +1169,25 @@ static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
static int local_init(FsContext *ctx)
{
int err = 0;
struct statfs stbuf;
#ifdef FS_IOC_GETVERSION
/*
* use ioc_getversion only if the ioctl is definied
*/
if (statfs(ctx->fs_root, &stbuf) < 0) {
return -1;
}
switch (stbuf.f_type) {
case EXT2_SUPER_MAGIC:
case BTRFS_SUPER_MAGIC:
case REISERFS_SUPER_MAGIC:
case XFS_SUPER_MAGIC:
ctx->exops.get_st_gen = local_ioc_getversion;
break;
}
#endif
if (ctx->export_flags & V9FS_SM_PASSTHROUGH) {
ctx->xops = passthrough_xattr_ops;
} else if (ctx->export_flags & V9FS_SM_MAPPED) {
@ -1186,23 +1202,8 @@ static int local_init(FsContext *ctx)
ctx->xops = passthrough_xattr_ops;
}
ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT;
#ifdef FS_IOC_GETVERSION
/*
* use ioc_getversion only if the iocl is definied
*/
err = statfs(ctx->fs_root, &stbuf);
if (!err) {
switch (stbuf.f_type) {
case EXT2_SUPER_MAGIC:
case BTRFS_SUPER_MAGIC:
case REISERFS_SUPER_MAGIC:
case XFS_SUPER_MAGIC:
ctx->exops.get_st_gen = local_ioc_getversion;
break;
}
}
#endif
return err;
return 0;
}
static int local_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse)