Messages in this thread | | | Date | Thu, 28 Oct 2010 14:08:53 -0400 | From | Vivek Goyal <> | Subject | Re: [PATCH 1/2] amiga floppy: Stop sharing request queue across multiple gendisks |
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On Thu, Oct 28, 2010 at 07:38:33PM +0200, Geert Uytterhoeven wrote: > On Thu, Sep 23, 2010 at 21:54, Vivek Goyal <vgoyal@redhat.com> wrote: > > o Use one request queue per gendisk instead of sharing request queue > > > > o Don't have hardware. No compile testing or run time testing done. Completely > > untested. > > > > Signed-off-by: Vivek Goyal <vgoyal@redhat.com> > > --- > > drivers/block/amiflop.c | 59 ++++++++++++++++++++++++++++++++++++++-------- > > 1 files changed, 48 insertions(+), 11 deletions(-) > > > > diff --git a/drivers/block/amiflop.c b/drivers/block/amiflop.c > > index 76f114f..ead8b77 100644 > > --- a/drivers/block/amiflop.c > > +++ b/drivers/block/amiflop.c > > @@ -114,8 +114,6 @@ static unsigned long int fd_def_df0 = FD_DD_3; /* default for df0 if it does > > module_param(fd_def_df0, ulong, 0); > > MODULE_LICENSE("GPL"); > > > > -static struct request_queue *floppy_queue; > > - > > /* > > * Macros > > */ > > @@ -164,6 +162,7 @@ static volatile int selected = -1; /* currently selected drive */ > > static int writepending; > > static int writefromint; > > static char *raw_buf; > > +static int fdc_queue; > > > > static DEFINE_SPINLOCK(amiflop_lock); > > > > @@ -1334,6 +1333,42 @@ static int get_track(int drive, int track) > > return -1; > > } > > > > +/* > > + * Round-robin between our available drives, doing one request from each > > + */ > > +static struct request *set_next_request(void) > > +{ > > + struct request_queue *q; > > + int cnt = FD_MAX_UNITS; > > + struct request *rq; > > + > > + /* Find next queue we can dispatch from */ > > + fdc_queue = fdc_queue + 1; > > + if (fdc_queue == FD_MAX_UNITS) > > + fdc_queue = 0; > > + > > + for(cnt = FD_MAX_UNITS; cnt > 0, cnt--) { > > + > > + if (unit[fdc_queue].type->code == FD_NODRIVE) { > > + if (++fdc_queue == FD_MAX_UNITS) > > + fdc_queue = 0; > > + cotinue; > > + } > > + > > + q = unit[fdc_queue].gendisk->queue; > > + if (q) { > > + rq = blk_fetch_request(q); > > + if (rq) > > + break; > > + } > > + > > + if (++fdc_queue == FD_MAX_UNITS) > > + fdc_queue = 0; > > + } > > + > > + return rq; > > +} > > drivers/block/amiflop.c:1344: warning: ‘rq’ may be used uninitialized > in this function > drivers/block/ataflop.c:1402: warning: ‘rq’ may be used uninitialized > in this function > > Should `rq' just be initialized to NULL? I looked at > floppy.c:set_next_request(), but it's > completely different. >
I think we should explicitly initialize rq=NULL so that we don't return a garbage value if we can't find any rq to dispatch.
I will send a patch to fix that.
Thanks Vivek -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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