Re: [PATCH 8/9] hw/9pfs/9p-synth: Replaced qemu_mutex_lock with QEMU_LOCK_GUARD

[Greg Kurz]

On Sat, 13 Mar 2021 07:43:38 +0200
Mahmoud Mandour <ma.mandourr@gmail.com> wrote:

> Thanks for the fast review. I asked on the QEMU IRC channel
> before committing whether to put all the changes into one patch
> or split them and was instructed that it was better to split them up.
> But in any case I was open to both ways and you can decide
> on the best way to go.
> 

People only do inline replies here. Please don't top-post for the
sake of clarity.

So, the instructions to split the patches is obviously the way to go. The
question here is rather : will each subsystem maintainer pick up patches
from this series or will only one maintainer pick up all the patches after
they have been acked by the other maintainers ?

> On Thu, Mar 11, 2021 at 1:59 PM Christian Schoenebeck <
> qemu_oss@crudebyte.com> wrote:
> 
> > On Donnerstag, 11. März 2021 12:52:45 CET Greg Kurz wrote:
> > > On Thu, 11 Mar 2021 11:49:06 +0100
> > >
> > > Christian Schoenebeck <qemu_oss@crudebyte.com> wrote:
> > > > On Donnerstag, 11. März 2021 04:15:37 CET Mahmoud Mandour wrote:
> > > > > Replaced a call to qemu_mutex_lock and its respective call to
> > > > > qemu_mutex_unlock and used QEMU_LOCK_GUARD macro in their place.
> > > > > This simplifies the code by removing the call required to unlock
> > > > > and also eliminates goto paths.
> > > > >
> > > > > Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
> > > > > ---
> > > > >
> > > > >  hw/9pfs/9p-synth.c | 12 ++++--------
> > > > >  1 file changed, 4 insertions(+), 8 deletions(-)
> > > > >
> > > > > diff --git a/hw/9pfs/9p-synth.c b/hw/9pfs/9p-synth.c
> > > > > index 7eb210ffa8..473ef914b0 100644
> > > > > --- a/hw/9pfs/9p-synth.c
> > > > > +++ b/hw/9pfs/9p-synth.c
> > > > > @@ -79,11 +79,11 @@ int qemu_v9fs_synth_mkdir(V9fsSynthNode *parent,
> > int
> > > > > mode, if (!parent) {
> > > > >
> > > > >          parent = &synth_root;
> > > > >
> > > > >      }
> > > > >
> > > > > -    qemu_mutex_lock(&synth_mutex);
> > > > > +    QEMU_LOCK_GUARD(&synth_mutex);
> > > > >
> > > > >      QLIST_FOREACH(tmp, &parent->child, sibling) {
> > > > >
> > > > >          if (!strcmp(tmp->name, name)) {
> > > > >
> > > > >              ret = EEXIST;
> > > > >
> > > > > -            goto err_out;
> > > > > +            return ret;
> > > > >
> > > > >          }
> > > > >
> > > > >      }
> > > > >      /* Add the name */
> > > > >
> > > > > @@ -94,8 +94,6 @@ int qemu_v9fs_synth_mkdir(V9fsSynthNode *parent,
> > int
> > > > > mode, node->attr, node->attr->inode);
> > > > >
> > > > >      *result = node;
> > > > >      ret = 0;
> > > > >
> > > > > -err_out:
> > > > > -    qemu_mutex_unlock(&synth_mutex);
> > > > >
> > > > >      return ret;
> > > > >
> > > > >  }
> > > > >
> > > > > @@ -116,11 +114,11 @@ int qemu_v9fs_synth_add_file(V9fsSynthNode
> > > > > *parent,
> > > > > int mode, parent = &synth_root;
> > > > >
> > > > >      }
> > > > >
> > > > > -    qemu_mutex_lock(&synth_mutex);
> > > > > +    QEMU_LOCK_GUARD(&synth_mutex);
> > > > >
> > > > >      QLIST_FOREACH(tmp, &parent->child, sibling) {
> > > > >
> > > > >          if (!strcmp(tmp->name, name)) {
> > > > >
> > > > >              ret = EEXIST;
> > > > >
> > > > > -            goto err_out;
> > > > > +            return ret;
> > > > >
> > > > >          }
> > > > >
> > > > >      }
> > > > >      /* Add file type and remove write bits */
> > > > >
> > > > > @@ -136,8 +134,6 @@ int qemu_v9fs_synth_add_file(V9fsSynthNode
> > *parent,
> > > > > int
> > > > > mode, pstrcpy(node->name, sizeof(node->name), name);
> > > > >
> > > > >      QLIST_INSERT_HEAD_RCU(&parent->child, node, sibling);
> > > > >      ret = 0;
> > > > >
> > > > > -err_out:
> > > > > -    qemu_mutex_unlock(&synth_mutex);
> > > > >
> > > > >      return ret;
> > > > >
> > > > >  }
> > > >
> > > > Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
> > > >
> > > > Greg, I suggest I'll push this onto my queue as you seem to be busy.
> > >
> > > This cleanup spans over multiple subsystems but I think it makes more
> > > sense to keep all these patches together. Let's wait for everyone to
> > > ack/review and then we'll decide how to merge the patches.
> >
> > Sure, makes sense.
> >
> >
> >
> >