On Sun, 2 May 2010 10:59:02 -0700
Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
> On Wed, Apr 14, 2010 at 11:21 PM, NeilBrown <neilb@xxxxxxx> wrote:
> > Hi all,
> > I thought it was time I posted my patch queue for review to be sure
> > it would be ready for the next merge window.
> >
> > Apart from sundry bug fixes and minor improvements there are two big
> > themes here
> > 1/ enhancements to level conversion so e.g. we can now convert RAID0
> > to RAID5 or RAID10 (near-2 only) and back.
> > 2/ general refactoring of bits of md code - some functions
> > (e.g. do_md_stop) had become really big and were just a mess of
> > stuff that all had to be done at much the same time. It is now
> > broken into somewhat meaningful parts. There is a deeper reason
> > for doing this refactoring .... you'll find out soon. :-)
> >
> > This is all available at
> > git://neil.brown.name/md for-next
> > and should be in linux-next in a day or two.
> >
> >
> > All review, testing, and comments most welcome.
> >
>
> A few fixes/enhancements while playing with the takeover code are available at:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/djbw/md.git for-neil
Thanks - they all make sense.
I've merged them with my queue and push them to my for-next branch.
NeilBrown
>
> Dan Williams (3):
> md/raid4: permit raid0 takeover
> md: notify mdstat waiters of level change
> md: allow integers to be passed to md/level
>
> drivers/md/md.c | 25 +++++++++++++++----------
> drivers/md/raid5.c | 32 +++++++++++++++++---------------
> 2 files changed, 32 insertions(+), 25 deletions(-)
>
> I'd like to get "raid6: fix recovery performance regression" in for
> 2.6.34. I pushed it out to the url below, let me know if you just
> want me to send it directly.
>
> git://git.kernel.org/pub/scm/linux/kernel/git/djbw/md.git fixes
>
> Dan Williams (1):
> raid6: fix recovery performance regression
>
> crypto/async_tx/async_raid6_recov.c | 21 +++++++++++++--------
> 1 files changed, 13 insertions(+), 8 deletions(-)
>
> Full diff of these 4 patches below (whitespace damaged):
>
> diff --git a/crypto/async_tx/async_raid6_recov.c
> b/crypto/async_tx/async_raid6_recov.c
> index 943f2ab..3df6746 100644
> --- a/crypto/async_tx/async_raid6_recov.c
> +++ b/crypto/async_tx/async_raid6_recov.c
> @@ -324,6 +324,7 @@ struct dma_async_tx_descriptor *
> async_raid6_2data_recov(int disks, size_t bytes, int faila, int failb,
> struct page **blocks, struct async_submit_ctl *submit)
> {
> + void *scribble = submit->scribble;
> int non_zero_srcs, i;
>
> BUG_ON(faila == failb);
> @@ -332,11 +333,13 @@ async_raid6_2data_recov(int disks, size_t bytes,
> int faila, int failb,
>
> pr_debug("%s: disks: %d len: %zu\n", __func__, disks, bytes);
>
> - /* we need to preserve the contents of 'blocks' for the async
> - * case, so punt to synchronous if a scribble buffer is not available
> + /* if a dma resource is not available or a scribble buffer is not
> + * available punt to the synchronous path. In the 'dma not
> + * available' case be sure to use the scribble buffer to
> + * preserve the content of 'blocks' as the caller intended.
> */
> - if (!submit->scribble) {
> - void **ptrs = (void **) blocks;
> + if (async_dma_find_channel(DMA_PQ) == NULL || !scribble) {
> + void **ptrs = scribble ? scribble : (void **) blocks;
>
> async_tx_quiesce(&submit->depend_tx);
> for (i = 0; i < disks; i++)
> @@ -406,11 +409,13 @@ async_raid6_datap_recov(int disks, size_t bytes,
> int faila,
>
> pr_debug("%s: disks: %d len: %zu\n", __func__, disks, bytes);
>
> - /* we need to preserve the contents of 'blocks' for the async
> - * case, so punt to synchronous if a scribble buffer is not available
> + /* if a dma resource is not available or a scribble buffer is not
> + * available punt to the synchronous path. In the 'dma not
> + * available' case be sure to use the scribble buffer to
> + * preserve the content of 'blocks' as the caller intended.
> */
> - if (!scribble) {
> - void **ptrs = (void **) blocks;
> + if (async_dma_find_channel(DMA_PQ) == NULL || !scribble) {
> + void **ptrs = scribble ? scribble : (void **) blocks;
>
> async_tx_quiesce(&submit->depend_tx);
> for (i = 0; i < disks; i++)
> diff --git a/drivers/md/md.c b/drivers/md/md.c
> index f177de0..e3ec0fd 100644
> --- a/drivers/md/md.c
> +++ b/drivers/md/md.c
> @@ -2935,9 +2935,10 @@ level_show(mddev_t *mddev, char *page)
> static ssize_t
> level_store(mddev_t *mddev, const char *buf, size_t len)
> {
> - char level[16];
> + char clevel[16];
> ssize_t rv = len;
> struct mdk_personality *pers;
> + long level;
> void *priv;
> mdk_rdev_t *rdev;
>
> @@ -2970,19 +2971,22 @@ level_store(mddev_t *mddev, const char *buf, size_t len)
> }
>
> /* Now find the new personality */
> - if (len == 0 || len >= sizeof(level))
> + if (len == 0 || len >= sizeof(clevel))
> return -EINVAL;
> - strncpy(level, buf, len);
> - if (level[len-1] == '\n')
> + strncpy(clevel, buf, len);
> + if (clevel[len-1] == '\n')
> len--;
> - level[len] = 0;
> + clevel[len] = 0;
> + if (strict_strtol(clevel, 10, &level))
> + level = LEVEL_NONE;
>
> - request_module("md-%s", level);
> + if (request_module("md-%s", clevel) != 0)
> + request_module("md-level-%s", clevel);
> spin_lock(&pers_lock);
> - pers = find_pers(LEVEL_NONE, level);
> + pers = find_pers(level, clevel);
> if (!pers || !try_module_get(pers->owner)) {
> spin_unlock(&pers_lock);
> - printk(KERN_WARNING "md: personality %s not loaded\n", level);
> + printk(KERN_WARNING "md: personality %s not loaded\n", clevel);
> return -EINVAL;
> }
> spin_unlock(&pers_lock);
> @@ -2995,7 +2999,7 @@ level_store(mddev_t *mddev, const char *buf, size_t len)
> if (!pers->takeover) {
> module_put(pers->owner);
> printk(KERN_WARNING "md: %s: %s does not support personality takeover\n",
> - mdname(mddev), level);
> + mdname(mddev), clevel);
> return -EINVAL;
> }
>
> @@ -3011,7 +3015,7 @@ level_store(mddev_t *mddev, const char *buf, size_t len)
> mddev->delta_disks = 0;
> module_put(pers->owner);
> printk(KERN_WARNING "md: %s: %s would not accept array\n",
> - mdname(mddev), level);
> + mdname(mddev), clevel);
> return PTR_ERR(priv);
> }
>
> @@ -3075,6 +3079,7 @@ level_store(mddev_t *mddev, const char *buf, size_t len)
> set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
> md_wakeup_thread(mddev->thread);
> sysfs_notify(&mddev->kobj, NULL, "level");
> + md_new_event(mddev);
> return rv;
> }
>
> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> index 042651b..d09c263 100644
> --- a/drivers/md/raid5.c
> +++ b/drivers/md/raid5.c
> @@ -5607,10 +5607,17 @@ static void raid5_quiesce(mddev_t *mddev, int state)
> }
>
>
> -static void *raid5_takeover_raid0(mddev_t *mddev)
> +static void *raid45_takeover_raid0(mddev_t *mddev, int level)
> {
> + struct raid0_private_data *raid0_priv = mddev->private;
>
> - mddev->new_level = 5;
> + /* for raid0 takeover only one zone is supported */
> + if (raid0_priv->nr_strip_zones > 1) {
> + printk(KERN_ERR "md: cannot takeover raid0 with more than one zone.\n");
> + return ERR_PTR(-EINVAL);
> + }
> +
> + mddev->new_level = level;
> mddev->new_layout = ALGORITHM_PARITY_N;
> mddev->new_chunk_sectors = mddev->chunk_sectors;
> mddev->raid_disks += 1;
> @@ -5746,22 +5753,13 @@ static int raid6_check_reshape(mddev_t *mddev)
> static void *raid5_takeover(mddev_t *mddev)
> {
> /* raid5 can take over:
> - * raid0 - if all devices are the same - make it a raid4 layout
> + * raid0 - if there is only one strip zone - make it a raid4 layout
> * raid1 - if there are two drives. We need to know the chunk size
> * raid4 - trivial - just use a raid4 layout.
> * raid6 - Providing it is a *_6 layout
> */
> - if (mddev->level == 0) {
> - /* for raid0 takeover only one zone is supported */
> - struct raid0_private_data *raid0_priv
> - = mddev->private;
> - if (raid0_priv->nr_strip_zones > 1) {
> - printk(KERN_ERR "md: cannot takeover raid 0 with more than one zone.\n");
> - return ERR_PTR(-EINVAL);
> - }
> - return raid5_takeover_raid0(mddev);
> - }
> -
> + if (mddev->level == 0)
> + return raid45_takeover_raid0(mddev, 5);
> if (mddev->level == 1)
> return raid5_takeover_raid1(mddev);
> if (mddev->level == 4) {
> @@ -5777,8 +5775,12 @@ static void *raid5_takeover(mddev_t *mddev)
>
> static void *raid4_takeover(mddev_t *mddev)
> {
> - /* raid4 can take over raid5 if layout is right.
> + /* raid4 can take over:
> + * raid0 - if there is only one strip zone
> + * raid5 - if layout is right
> */
> + if (mddev->level == 0)
> + return raid45_takeover_raid0(mddev, 4);
> if (mddev->level == 5 &&
> mddev->layout == ALGORITHM_PARITY_N) {
> mddev->new_layout = 0;
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