| Message ID | 1475055746-22401-11-git-send-email-konrad.wilk@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Sep 28, 2016 at 05:42:24AM -0400, Konrad Rzeszutek Wilk wrote: > return values. For success they used to be 1 ([SAVE,RESTORE]_BEGIN), > 0 if guest did not have any tmem (but only for SAVE_BEGIN), and > -1 for any type of failure. > > And SAVE_END (which you would think would mirror SAVE_BEGIN) > had 0 for success and -1 if guest did not any tmem enabled for it. > > This is confusing. Now the code will return 0 if the operation was > success. Various XEN_EXX values are returned if tmem is not enabled > or the operation could not performed. > > The xc_tmem.c code only needs one place to check - where we use > SAVE_BEGIN. The place where RESTORE_BEGIN is used will have errno > with the proper error value and return will be -1, so will still > fail properly. > > Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > > --- > Cc: Ian Jackson <ian.jackson@eu.citrix.com> > Cc: Wei Liu <wei.liu2@citrix.com> > > v1: First submission > --- > tools/libxc/xc_tmem.c | 14 +++++++++++--- Acked-by: Wei Liu <wei.liu2@citrix.com>
>>> On 28.09.16 at 11:42, <konrad.wilk@oracle.com> wrote: > case XEN_SYSCTL_TMEM_OP_RESTORE_BEGIN: > if ( client == NULL && (client = client_create(cli_id)) != NULL ) > - return 1; > + rc = 0; > + else > + rc = -EEXIST; > break; I don't think the same error code should be used for both a pre-existing client and creation failure. Jan
diff --git a/tools/libxc/xc_tmem.c b/tools/libxc/xc_tmem.c index 7873674..a843210 100644 --- a/tools/libxc/xc_tmem.c +++ b/tools/libxc/xc_tmem.c @@ -216,15 +216,23 @@ int xc_tmem_save(xc_interface *xch, int dom, int io_fd, int live, int field_marker) { int marker = field_marker; - int i, j; + int i, j, rc; uint32_t flags; uint32_t minusone = -1; uint32_t pool_id; struct tmem_handle *h; xen_sysctl_tmem_client_t info; - if ( xc_tmem_control(xch,0,XEN_SYSCTL_TMEM_OP_SAVE_BEGIN,dom,live,0,NULL) <= 0 ) - return 0; + rc = xc_tmem_control(xch, 0, XEN_SYSCTL_TMEM_OP_SAVE_BEGIN, + dom, live, 0, NULL); + if ( rc ) + { + /* Nothing to save - no tmem enabled. */ + if ( errno == ENOENT ) + return 0; + + return rc; + } if ( write_exact(io_fd, &marker, sizeof(marker)) ) return -1; diff --git a/xen/common/tmem.c b/xen/common/tmem.c index ab354b6..997f2b0 100644 --- a/xen/common/tmem.c +++ b/xen/common/tmem.c @@ -1656,30 +1656,31 @@ static int tmemc_save_subop(int cli_id, uint32_t pool_id, struct client *client = tmem_client_from_cli_id(cli_id); uint32_t p; struct tmem_page_descriptor *pgp, *pgp2; - int rc = -1; + int rc = -ENOENT; switch(subop) { case XEN_SYSCTL_TMEM_OP_SAVE_BEGIN: if ( client == NULL ) - return 0; + break; for (p = 0; p < MAX_POOLS_PER_DOMAIN; p++) if ( client->pools[p] != NULL ) break; + if ( p == MAX_POOLS_PER_DOMAIN ) - { - rc = 0; break; - } + client->was_frozen = client->info.flags.u.frozen; client->info.flags.u.frozen = 1; if ( arg1 != 0 ) client->info.flags.u.migrating = 1; - rc = 1; + rc = 0; break; case XEN_SYSCTL_TMEM_OP_RESTORE_BEGIN: if ( client == NULL && (client = client_create(cli_id)) != NULL ) - return 1; + rc = 0; + else + rc = -EEXIST; break; case XEN_SYSCTL_TMEM_OP_SAVE_END: if ( client == NULL )
return values. For success they used to be 1 ([SAVE,RESTORE]_BEGIN), 0 if guest did not have any tmem (but only for SAVE_BEGIN), and -1 for any type of failure. And SAVE_END (which you would think would mirror SAVE_BEGIN) had 0 for success and -1 if guest did not any tmem enabled for it. This is confusing. Now the code will return 0 if the operation was success. Various XEN_EXX values are returned if tmem is not enabled or the operation could not performed. The xc_tmem.c code only needs one place to check - where we use SAVE_BEGIN. The place where RESTORE_BEGIN is used will have errno with the proper error value and return will be -1, so will still fail properly. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> --- Cc: Ian Jackson <ian.jackson@eu.citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> v1: First submission --- tools/libxc/xc_tmem.c | 14 +++++++++++--- xen/common/tmem.c | 15 ++++++++------- 2 files changed, 19 insertions(+), 10 deletions(-)