Message ID | 1462341450-5507-4-git-send-email-hare@suse.de (mailing list archive) |
---|---|
State | Not Applicable, archived |
Delegated to: | Mike Snitzer |
Headers | show |
On Wed, May 04, 2016 at 07:57:27AM +0200, Hannes Reinecke wrote: > The 'udev_sync' attribute is pointless without a cookie, so we > can as well use the existence of the 'cookie' argument for > the same function. Well, I've already said that we should leave the cookies inside dm_simplecmd, and if we do that, we need the udev_sync code. One reason to do this is that cookies aren't just used for synchronization. They are the mechanism by which udev flags are sent to device-mapper. Now it just so happens that we currently aren't sending any udev_flags when we are not asking for synchronization, but that doesn't mean it will always be the case. So there could be a use knowing whether or not we need synchronization, even in cases where we know that we defintely need a cookie to pass flags to udev. While again, we could do this by checking udev_flags as well and then passing in a cookie and it wouldn't break anything, I just don't see the point of passing in a pointer to a value that must be zero when we pass it, and we're not allowed to use the result when we get it back. -Ben > > Signed-off-by: Hannes Reinecke <hare@suse.com> > --- > libmultipath/devmapper.c | 21 ++++++++++++--------- > 1 file changed, 12 insertions(+), 9 deletions(-) > > diff --git a/libmultipath/devmapper.c b/libmultipath/devmapper.c > index ab71fda..9facbb9 100644 > --- a/libmultipath/devmapper.c > +++ b/libmultipath/devmapper.c > @@ -207,12 +207,10 @@ dm_prereq (void) > #define do_deferred(x) ((x) == DEFERRED_REMOVE_ON || (x) == DEFERRED_REMOVE_IN_PROGRESS) > > static int > -dm_simplecmd (int task, const char *name, int no_flush, int need_sync, > +dm_simplecmd (int task, const char *name, int no_flush, > uint16_t udev_flags, int deferred_remove, uint32_t *cookie) > { > int r = 0; > - int udev_wait_flag = (need_sync && (task == DM_DEVICE_RESUME || > - task == DM_DEVICE_REMOVE)); > struct dm_task *dmt; > > if (!(dmt = dm_task_create (task))) > @@ -231,7 +229,7 @@ dm_simplecmd (int task, const char *name, int no_flush, int need_sync, > if (do_deferred(deferred_remove)) > dm_task_deferred_remove(dmt); > #endif > - if (udev_wait_flag && > + if (cookie && > !dm_task_set_cookie(dmt, cookie, > DM_UDEV_DISABLE_LIBRARY_FALLBACK | udev_flags)) { > dm_udev_complete(*cookie); > @@ -239,7 +237,7 @@ dm_simplecmd (int task, const char *name, int no_flush, int need_sync, > } > r = dm_task_run (dmt); > > - if (udev_wait_flag) { > + if (cookie) { > if (!r) > dm_udev_complete(*cookie); > else > @@ -254,22 +252,27 @@ extern int > dm_simplecmd_flush (int task, const char *name, uint16_t udev_flags) { > uint32_t cookie = 0; > > - return dm_simplecmd(task, name, 0, 1, udev_flags, 0, &cookie); > + if (task == DM_DEVICE_RESUME || > + task == DM_DEVICE_REMOVE) > + return dm_simplecmd(task, name, 0, udev_flags, 0, &cookie); > + else > + return dm_simplecmd(task, name, 0, udev_flags, 0, NULL); > } > > extern int > dm_simplecmd_noflush (int task, const char *name, int needsync, uint16_t udev_flags) { > uint32_t cookie = 0; > > - return dm_simplecmd(task, name, 1, needsync, udev_flags, 0, &cookie); > + return dm_simplecmd(task, name, 1, udev_flags, 0, > + needsync ? &cookie : NULL); > } > > static int > dm_device_remove (const char *name, int needsync, int deferred_remove) { > uint32_t cookie = 0; > > - return dm_simplecmd(DM_DEVICE_REMOVE, name, 0, needsync, 0, > - deferred_remove, &cookie); > + return dm_simplecmd(DM_DEVICE_REMOVE, name, 0, 0, > + deferred_remove, needsync ? &cookie : NULL); > } > > static int > -- > 2.6.6 -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel
diff --git a/libmultipath/devmapper.c b/libmultipath/devmapper.c index ab71fda..9facbb9 100644 --- a/libmultipath/devmapper.c +++ b/libmultipath/devmapper.c @@ -207,12 +207,10 @@ dm_prereq (void) #define do_deferred(x) ((x) == DEFERRED_REMOVE_ON || (x) == DEFERRED_REMOVE_IN_PROGRESS) static int -dm_simplecmd (int task, const char *name, int no_flush, int need_sync, +dm_simplecmd (int task, const char *name, int no_flush, uint16_t udev_flags, int deferred_remove, uint32_t *cookie) { int r = 0; - int udev_wait_flag = (need_sync && (task == DM_DEVICE_RESUME || - task == DM_DEVICE_REMOVE)); struct dm_task *dmt; if (!(dmt = dm_task_create (task))) @@ -231,7 +229,7 @@ dm_simplecmd (int task, const char *name, int no_flush, int need_sync, if (do_deferred(deferred_remove)) dm_task_deferred_remove(dmt); #endif - if (udev_wait_flag && + if (cookie && !dm_task_set_cookie(dmt, cookie, DM_UDEV_DISABLE_LIBRARY_FALLBACK | udev_flags)) { dm_udev_complete(*cookie); @@ -239,7 +237,7 @@ dm_simplecmd (int task, const char *name, int no_flush, int need_sync, } r = dm_task_run (dmt); - if (udev_wait_flag) { + if (cookie) { if (!r) dm_udev_complete(*cookie); else @@ -254,22 +252,27 @@ extern int dm_simplecmd_flush (int task, const char *name, uint16_t udev_flags) { uint32_t cookie = 0; - return dm_simplecmd(task, name, 0, 1, udev_flags, 0, &cookie); + if (task == DM_DEVICE_RESUME || + task == DM_DEVICE_REMOVE) + return dm_simplecmd(task, name, 0, udev_flags, 0, &cookie); + else + return dm_simplecmd(task, name, 0, udev_flags, 0, NULL); } extern int dm_simplecmd_noflush (int task, const char *name, int needsync, uint16_t udev_flags) { uint32_t cookie = 0; - return dm_simplecmd(task, name, 1, needsync, udev_flags, 0, &cookie); + return dm_simplecmd(task, name, 1, udev_flags, 0, + needsync ? &cookie : NULL); } static int dm_device_remove (const char *name, int needsync, int deferred_remove) { uint32_t cookie = 0; - return dm_simplecmd(DM_DEVICE_REMOVE, name, 0, needsync, 0, - deferred_remove, &cookie); + return dm_simplecmd(DM_DEVICE_REMOVE, name, 0, 0, + deferred_remove, needsync ? &cookie : NULL); } static int
The 'udev_sync' attribute is pointless without a cookie, so we can as well use the existence of the 'cookie' argument for the same function. Signed-off-by: Hannes Reinecke <hare@suse.com> --- libmultipath/devmapper.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-)