On Tue, 19 Jan 2021 14:31:26 +0100 Christian Schoenebeck <qemu_...@crudebyte.com> wrote:
> On Montag, 18. Januar 2021 15:22:59 CET Greg Kurz wrote: > > The fid_list is currently open-coded. This doesn't seem to serve any > > purpose that cannot be met with QEMU's generic lists. Let's go for a > > QSIMPLEQ : this will allow to add new fids at the end of the list and > > to improve the logic in v9fs_mark_fids_unreclaim(). > > > > Signed-off-by: Greg Kurz <gr...@kaod.org> > > In general LGTM hence: > > Reviewed-by: Christian Schoenebeck <qemu_...@crudebyte.com> > > Some comments below ... > > > --- > > hw/9pfs/9p.c | 41 ++++++++++++++++++----------------------- > > hw/9pfs/9p.h | 4 ++-- > > 2 files changed, 20 insertions(+), 25 deletions(-) > > > > diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c > > index 37c3379b7462..b65f320e6518 100644 > > --- a/hw/9pfs/9p.c > > +++ b/hw/9pfs/9p.c > > @@ -260,7 +260,7 @@ static V9fsFidState *coroutine_fn get_fid(V9fsPDU *pdu, > > int32_t fid) V9fsFidState *f; > > V9fsState *s = pdu->s; > > > > - for (f = s->fid_list; f; f = f->next) { > > + QSIMPLEQ_FOREACH(f, &s->fid_list, next) { > > BUG_ON(f->clunked); > > if (f->fid == fid) { > > /* > > @@ -295,7 +295,7 @@ static V9fsFidState *alloc_fid(V9fsState *s, int32_t > > fid) { > > V9fsFidState *f; > > > > - for (f = s->fid_list; f; f = f->next) { > > + QSIMPLEQ_FOREACH(f, &s->fid_list, next) { > > /* If fid is already there return NULL */ > > BUG_ON(f->clunked); > > if (f->fid == fid) { > > @@ -311,8 +311,7 @@ static V9fsFidState *alloc_fid(V9fsState *s, int32_t > > fid) * reclaim won't close the file descriptor > > */ > > f->flags |= FID_REFERENCED; > > - f->next = s->fid_list; > > - s->fid_list = f; > > + QSIMPLEQ_INSERT_HEAD(&s->fid_list, f, next); > > Not related to this series, but I wonder why queue.h wraps everything into: > > do { > ... > } while (0); > Note, this is do { ... } while (0) *without* the trailing semi-colon, which is the corner stone of this trick. > No comment about it in git history. Looks like a leftover of its initial > import from 2009. > This is the usual way to define multi-statement macros. More details here: http://c-faq.com/cpp/multistmt.html > > v9fs_readdir_init(s->proto_version, &f->fs.dir); > > v9fs_readdir_init(s->proto_version, &f->fs_reclaim.dir); > > @@ -401,20 +400,16 @@ static int coroutine_fn put_fid(V9fsPDU *pdu, > > V9fsFidState *fidp) > > > > static V9fsFidState *clunk_fid(V9fsState *s, int32_t fid) > > { > > - V9fsFidState **fidpp, *fidp; > > + V9fsFidState *fidp; > > > > - for (fidpp = &s->fid_list; *fidpp; fidpp = &(*fidpp)->next) { > > - if ((*fidpp)->fid == fid) { > > - break; > > + QSIMPLEQ_FOREACH(fidp, &s->fid_list, next) { > > + if (fidp->fid == fid) { > > + QSIMPLEQ_REMOVE(&s->fid_list, fidp, V9fsFidState, next); > > + fidp->clunked = true; > > + return fidp; > > } > > } > > - if (*fidpp == NULL) { > > - return NULL; > > - } > > - fidp = *fidpp; > > - *fidpp = fidp->next; > > - fidp->clunked = true; > > - return fidp; > > + return NULL; > > } > > Good cleanup there! > Thanks ! > > void coroutine_fn v9fs_reclaim_fd(V9fsPDU *pdu) > > @@ -423,7 +418,7 @@ void coroutine_fn v9fs_reclaim_fd(V9fsPDU *pdu) > > V9fsState *s = pdu->s; > > V9fsFidState *f, *reclaim_list = NULL; > > > > - for (f = s->fid_list; f; f = f->next) { > > + QSIMPLEQ_FOREACH(f, &s->fid_list, next) { > > /* > > * Unlink fids cannot be reclaimed. Check > > * for them and skip them. Also skip fids > > @@ -505,7 +500,7 @@ static int coroutine_fn v9fs_mark_fids_unreclaim(V9fsPDU > > *pdu, V9fsPath *path) V9fsFidState *fidp; > > > > again: > > - for (fidp = s->fid_list; fidp; fidp = fidp->next) { > > + QSIMPLEQ_FOREACH(fidp, &s->fid_list, next) { > > if (fidp->path.size != path->size) { > > continue; > > } > > @@ -537,13 +532,13 @@ static void coroutine_fn virtfs_reset(V9fsPDU *pdu) > > V9fsFidState *fidp; > > > > /* Free all fids */ > > - while (s->fid_list) { > > + while (!QSIMPLEQ_EMPTY(&s->fid_list)) { > > /* Get fid */ > > - fidp = s->fid_list; > > + fidp = QSIMPLEQ_FIRST(&s->fid_list); > > fidp->ref++; > > > > /* Clunk fid */ > > - s->fid_list = fidp->next; > > + QSIMPLEQ_REMOVE(&s->fid_list, fidp, V9fsFidState, next); > > fidp->clunked = true; > > > > put_fid(pdu, fidp); > > @@ -3121,7 +3116,7 @@ static int coroutine_fn v9fs_complete_rename(V9fsPDU > > *pdu, V9fsFidState *fidp, * Fixup fid's pointing to the old name to > > * start pointing to the new name > > */ > > - for (tfidp = s->fid_list; tfidp; tfidp = tfidp->next) { > > + QSIMPLEQ_FOREACH(tfidp, &s->fid_list, next) { > > if (v9fs_path_is_ancestor(&fidp->path, &tfidp->path)) { > > /* replace the name */ > > v9fs_fix_path(&tfidp->path, &new_path, > > strlen(fidp->path.data)); @@ -3215,7 +3210,7 @@ static int coroutine_fn > > v9fs_fix_fid_paths(V9fsPDU *pdu, V9fsPath *olddir, * Fixup fid's pointing > > to the old name to > > * start pointing to the new name > > */ > > - for (tfidp = s->fid_list; tfidp; tfidp = tfidp->next) { > > + QSIMPLEQ_FOREACH(tfidp, &s->fid_list, next) { > > if (v9fs_path_is_ancestor(&oldpath, &tfidp->path)) { > > /* replace the name */ > > v9fs_fix_path(&tfidp->path, &newpath, strlen(oldpath.data)); > > @@ -4081,7 +4076,7 @@ int v9fs_device_realize_common(V9fsState *s, const > > V9fsTransport *t, s->ctx.fmode = fse->fmode; > > s->ctx.dmode = fse->dmode; > > > > - s->fid_list = NULL; > > + QSIMPLEQ_INIT(&s->fid_list); > > qemu_co_rwlock_init(&s->rename_lock); > > > > if (s->ops->init(&s->ctx, errp) < 0) { > > diff --git a/hw/9pfs/9p.h b/hw/9pfs/9p.h > > index 93656323d1d7..85fb6930b0ca 100644 > > --- a/hw/9pfs/9p.h > > +++ b/hw/9pfs/9p.h > > @@ -280,7 +280,7 @@ struct V9fsFidState { > > uid_t uid; > > int ref; > > bool clunked; > > - V9fsFidState *next; > > + QSIMPLEQ_ENTRY(V9fsFidState) next; > > V9fsFidState *rclm_lst; > > }; > > Is there a reason for not migrating 'rclm_lst' as well? > Yeah. I did consider doing so at first but these were too many changes. Also, the fid list and the reclaim list have quite different needs, that each deserve its own patch. > Anyway, if you decide to do that as well, then it would IMO be fine with a > separate patch later on, not worth making it more complicated with a v2 just > for that. Yes, I already have a patch to convert the reclaim list to QSLIST. I'll post it later as it is merely cosmetic, while this series changes the behavior. > > @@ -339,7 +339,7 @@ typedef struct { > > struct V9fsState { > > QLIST_HEAD(, V9fsPDU) free_list; > > QLIST_HEAD(, V9fsPDU) active_list; > > - V9fsFidState *fid_list; > > + QSIMPLEQ_HEAD(, V9fsFidState) fid_list; > > Not an issue for this series, but I wonder whether that macro's first > argument > shouldn't simply be dropped in queue.h, because there are only 2 occurences > in > the entire QEMU code base using it. It looks like nobody really needs it. > A similar macro exist for the other list types as well, with some more users. If we go for such a change, I think this should stay consistent accros list types. All users should hence be audited first. > > FileOperations *ops; > > FsContext ctx; > > char *tag; > > Best regards, > Christian Schoenebeck > >