Re: [PATCH] xen/blkback: unmap all persistent grants when frontend gets disconnected
On Mon, Sep 08, 2014 at 03:21:33PM +0200, Vitaly Kuznetsov wrote: > blkback does not unmap persistent grants when frontend goes to Closed > state (e.g. when blkfront module is being removed). This leads to the > following in guest's dmesg: > > [ 343.243825] xen:grant_table: WARNING: g.e. 0x445 still in use! > [ 343.243825] xen:grant_table: WARNING: g.e. 0x42a still in use! > ... > > When load module -> use device -> unload module sequence is performed > multiple times > it is possible to hit BUG() condition in blkfront module: > > [ 343.243825] kernel BUG at drivers/block/xen-blkfront.c:954! > [ 343.243825] invalid opcode: [#1] SMP > [ 343.243825] Modules linked in: xen_blkfront(-) ata_generic pata_acpi [last > unloaded: xen_blkfront] > ... > [ 343.243825] Call Trace: > [ 343.243825] [] ? unregister_xenbus_watch+0x16f/0x1e0 > [ 343.243825] [] blkfront_remove+0x3f/0x140 [xen_blkfront] > ... > [ 343.243825] RIP [] blkif_free+0x34e/0x360 [xen_blkfront] > [ 343.243825] RSP > > We don't need to keep these grants if we're disconnecting as frontend might > already > forgot about them. Solve the issue by moving xen_blkbk_free_caches() call from > xen_blkif_free() to xen_blkif_disconnect(). > > Now we can see the following: > [ 928.590893] xen:grant_table: WARNING: g.e. 0x587 still in use! > [ 928.591861] xen:grant_table: WARNING: g.e. 0x372 still in use! > ... > [ 929.592146] xen:grant_table: freeing g.e. 0x587 > [ 929.597174] xen:grant_table: freeing g.e. 0x372 > ... > > Backend does not keep persistent grants any more, reconnect works fine. Reviewed-by: Konrad Rzeszutek Wilk David, I usually combine the 'block' related patches in one branch and send them to Jens for the merge window. Want to do it the same way or do you want to alter the workflow? > > Signed-off-by: Vitaly Kuznetsov > --- > drivers/block/xen-blkback/xenbus.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/block/xen-blkback/xenbus.c > b/drivers/block/xen-blkback/xenbus.c > index 3a8b810..54f4089 100644 > --- a/drivers/block/xen-blkback/xenbus.c > +++ b/drivers/block/xen-blkback/xenbus.c > @@ -270,6 +270,9 @@ static int xen_blkif_disconnect(struct xen_blkif *blkif) > blkif->blk_rings.common.sring = NULL; > } > > + /* Remove all persistent grants and the cache of ballooned pages. */ > + xen_blkbk_free_caches(blkif); > + > return 0; > } > > @@ -281,9 +284,6 @@ static void xen_blkif_free(struct xen_blkif *blkif) > xen_blkif_disconnect(blkif); > xen_vbd_free(>vbd); > > - /* Remove all persistent grants and the cache of ballooned pages. */ > - xen_blkbk_free_caches(blkif); > - > /* Make sure everything is drained before shutting down */ > BUG_ON(blkif->persistent_gnt_c != 0); > BUG_ON(atomic_read(>persistent_gnt_in_use) != 0); > -- > 1.9.3 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] xen/blkback: unmap all persistent grants when frontend gets disconnected
On Mon, Sep 08, 2014 at 03:21:33PM +0200, Vitaly Kuznetsov wrote: blkback does not unmap persistent grants when frontend goes to Closed state (e.g. when blkfront module is being removed). This leads to the following in guest's dmesg: [ 343.243825] xen:grant_table: WARNING: g.e. 0x445 still in use! [ 343.243825] xen:grant_table: WARNING: g.e. 0x42a still in use! ... When load module - use device - unload module sequence is performed multiple times it is possible to hit BUG() condition in blkfront module: [ 343.243825] kernel BUG at drivers/block/xen-blkfront.c:954! [ 343.243825] invalid opcode: [#1] SMP [ 343.243825] Modules linked in: xen_blkfront(-) ata_generic pata_acpi [last unloaded: xen_blkfront] ... [ 343.243825] Call Trace: [ 343.243825] [814111ef] ? unregister_xenbus_watch+0x16f/0x1e0 [ 343.243825] [a0016fbf] blkfront_remove+0x3f/0x140 [xen_blkfront] ... [ 343.243825] RIP [a0016aae] blkif_free+0x34e/0x360 [xen_blkfront] [ 343.243825] RSP 88001eb8fdc0 We don't need to keep these grants if we're disconnecting as frontend might already forgot about them. Solve the issue by moving xen_blkbk_free_caches() call from xen_blkif_free() to xen_blkif_disconnect(). Now we can see the following: [ 928.590893] xen:grant_table: WARNING: g.e. 0x587 still in use! [ 928.591861] xen:grant_table: WARNING: g.e. 0x372 still in use! ... [ 929.592146] xen:grant_table: freeing g.e. 0x587 [ 929.597174] xen:grant_table: freeing g.e. 0x372 ... Backend does not keep persistent grants any more, reconnect works fine. Reviewed-by: Konrad Rzeszutek Wilk konrad.w...@oracle.com David, I usually combine the 'block' related patches in one branch and send them to Jens for the merge window. Want to do it the same way or do you want to alter the workflow? Signed-off-by: Vitaly Kuznetsov vkuzn...@redhat.com --- drivers/block/xen-blkback/xenbus.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index 3a8b810..54f4089 100644 --- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -270,6 +270,9 @@ static int xen_blkif_disconnect(struct xen_blkif *blkif) blkif-blk_rings.common.sring = NULL; } + /* Remove all persistent grants and the cache of ballooned pages. */ + xen_blkbk_free_caches(blkif); + return 0; } @@ -281,9 +284,6 @@ static void xen_blkif_free(struct xen_blkif *blkif) xen_blkif_disconnect(blkif); xen_vbd_free(blkif-vbd); - /* Remove all persistent grants and the cache of ballooned pages. */ - xen_blkbk_free_caches(blkif); - /* Make sure everything is drained before shutting down */ BUG_ON(blkif-persistent_gnt_c != 0); BUG_ON(atomic_read(blkif-persistent_gnt_in_use) != 0); -- 1.9.3 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH] xen/blkback: unmap all persistent grants when frontend gets disconnected
blkback does not unmap persistent grants when frontend goes to Closed state (e.g. when blkfront module is being removed). This leads to the following in guest's dmesg: [ 343.243825] xen:grant_table: WARNING: g.e. 0x445 still in use! [ 343.243825] xen:grant_table: WARNING: g.e. 0x42a still in use! ... When load module -> use device -> unload module sequence is performed multiple times it is possible to hit BUG() condition in blkfront module: [ 343.243825] kernel BUG at drivers/block/xen-blkfront.c:954! [ 343.243825] invalid opcode: [#1] SMP [ 343.243825] Modules linked in: xen_blkfront(-) ata_generic pata_acpi [last unloaded: xen_blkfront] ... [ 343.243825] Call Trace: [ 343.243825] [] ? unregister_xenbus_watch+0x16f/0x1e0 [ 343.243825] [] blkfront_remove+0x3f/0x140 [xen_blkfront] ... [ 343.243825] RIP [] blkif_free+0x34e/0x360 [xen_blkfront] [ 343.243825] RSP We don't need to keep these grants if we're disconnecting as frontend might already forgot about them. Solve the issue by moving xen_blkbk_free_caches() call from xen_blkif_free() to xen_blkif_disconnect(). Now we can see the following: [ 928.590893] xen:grant_table: WARNING: g.e. 0x587 still in use! [ 928.591861] xen:grant_table: WARNING: g.e. 0x372 still in use! ... [ 929.592146] xen:grant_table: freeing g.e. 0x587 [ 929.597174] xen:grant_table: freeing g.e. 0x372 ... Backend does not keep persistent grants any more, reconnect works fine. Signed-off-by: Vitaly Kuznetsov --- drivers/block/xen-blkback/xenbus.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index 3a8b810..54f4089 100644 --- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -270,6 +270,9 @@ static int xen_blkif_disconnect(struct xen_blkif *blkif) blkif->blk_rings.common.sring = NULL; } + /* Remove all persistent grants and the cache of ballooned pages. */ + xen_blkbk_free_caches(blkif); + return 0; } @@ -281,9 +284,6 @@ static void xen_blkif_free(struct xen_blkif *blkif) xen_blkif_disconnect(blkif); xen_vbd_free(>vbd); - /* Remove all persistent grants and the cache of ballooned pages. */ - xen_blkbk_free_caches(blkif); - /* Make sure everything is drained before shutting down */ BUG_ON(blkif->persistent_gnt_c != 0); BUG_ON(atomic_read(>persistent_gnt_in_use) != 0); -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH] xen/blkback: unmap all persistent grants when frontend gets disconnected
blkback does not unmap persistent grants when frontend goes to Closed state (e.g. when blkfront module is being removed). This leads to the following in guest's dmesg: [ 343.243825] xen:grant_table: WARNING: g.e. 0x445 still in use! [ 343.243825] xen:grant_table: WARNING: g.e. 0x42a still in use! ... When load module - use device - unload module sequence is performed multiple times it is possible to hit BUG() condition in blkfront module: [ 343.243825] kernel BUG at drivers/block/xen-blkfront.c:954! [ 343.243825] invalid opcode: [#1] SMP [ 343.243825] Modules linked in: xen_blkfront(-) ata_generic pata_acpi [last unloaded: xen_blkfront] ... [ 343.243825] Call Trace: [ 343.243825] [814111ef] ? unregister_xenbus_watch+0x16f/0x1e0 [ 343.243825] [a0016fbf] blkfront_remove+0x3f/0x140 [xen_blkfront] ... [ 343.243825] RIP [a0016aae] blkif_free+0x34e/0x360 [xen_blkfront] [ 343.243825] RSP 88001eb8fdc0 We don't need to keep these grants if we're disconnecting as frontend might already forgot about them. Solve the issue by moving xen_blkbk_free_caches() call from xen_blkif_free() to xen_blkif_disconnect(). Now we can see the following: [ 928.590893] xen:grant_table: WARNING: g.e. 0x587 still in use! [ 928.591861] xen:grant_table: WARNING: g.e. 0x372 still in use! ... [ 929.592146] xen:grant_table: freeing g.e. 0x587 [ 929.597174] xen:grant_table: freeing g.e. 0x372 ... Backend does not keep persistent grants any more, reconnect works fine. Signed-off-by: Vitaly Kuznetsov vkuzn...@redhat.com --- drivers/block/xen-blkback/xenbus.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index 3a8b810..54f4089 100644 --- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -270,6 +270,9 @@ static int xen_blkif_disconnect(struct xen_blkif *blkif) blkif-blk_rings.common.sring = NULL; } + /* Remove all persistent grants and the cache of ballooned pages. */ + xen_blkbk_free_caches(blkif); + return 0; } @@ -281,9 +284,6 @@ static void xen_blkif_free(struct xen_blkif *blkif) xen_blkif_disconnect(blkif); xen_vbd_free(blkif-vbd); - /* Remove all persistent grants and the cache of ballooned pages. */ - xen_blkbk_free_caches(blkif); - /* Make sure everything is drained before shutting down */ BUG_ON(blkif-persistent_gnt_c != 0); BUG_ON(atomic_read(blkif-persistent_gnt_in_use) != 0); -- 1.9.3 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
