On 11/10/2011 10:25 AM, Peng Tao wrote:
> As discussed earlier, it is better for block client to allocate memory for
> tracking extents state before submitting bio. So the patch does it by allocating
> a short_extent for every INVALID extent touched by write pagelist and for
> every zeroing page we created, saving them in layout header. Then in end_io we
> can just use them to create commit list items and avoid memory allocation there.
>
> Signed-off-by: Peng Tao <peng_tao@xxxxxxx>
> ---
> fs/nfs/blocklayout/blocklayout.c | 74 +++++++++++++++++++++++++++++--------
> fs/nfs/blocklayout/blocklayout.h | 9 ++++-
> fs/nfs/blocklayout/extents.c | 62 +++++++++++++++++++++++++++-----
> 3 files changed, 119 insertions(+), 26 deletions(-)
>
> diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
> index 3eaea2b..3fdfb29 100644
> --- a/fs/nfs/blocklayout/blocklayout.c
> +++ b/fs/nfs/blocklayout/blocklayout.c
> @@ -90,8 +90,9 @@ static int is_writable(struct pnfs_block_extent *be, sector_t isect)
> */
> struct parallel_io {
> struct kref refcnt;
> - void (*pnfs_callback) (void *data);
> + void (*pnfs_callback) (void *data, int num_se);
> void *data;
> + int bse_count;
> };
>
> static inline struct parallel_io *alloc_parallel(void *data)
> @@ -102,6 +103,7 @@ static inline struct parallel_io *alloc_parallel(void *data)
> if (rv) {
> rv->data = data;
> kref_init(&rv->refcnt);
> + rv->bse_count = 0;
> }
> return rv;
> }
> @@ -116,7 +118,7 @@ static void destroy_parallel(struct kref *kref)
> struct parallel_io *p = container_of(kref, struct parallel_io, refcnt);
>
> dprintk("%s enter\n", __func__);
> - p->pnfs_callback(p->data);
> + p->pnfs_callback(p->data, p->bse_count);
> kfree(p);
> }
>
> @@ -211,7 +213,7 @@ static void bl_read_cleanup(struct work_struct *work)
> }
>
> static void
> -bl_end_par_io_read(void *data)
> +bl_end_par_io_read(void *data, int unused)
> {
> struct nfs_read_data *rdata = data;
>
> @@ -312,6 +314,7 @@ static void mark_extents_written(struct pnfs_block_layout *bl,
> {
> sector_t isect, end;
> struct pnfs_block_extent *be;
> + struct pnfs_block_short_extent *se;
>
> dprintk("%s(%llu, %u)\n", __func__, offset, count);
> if (count == 0)
> @@ -324,8 +327,11 @@ static void mark_extents_written(struct pnfs_block_layout *bl,
> be = bl_find_get_extent(bl, isect, NULL);
> BUG_ON(!be); /* FIXME */
> len = min(end, be->be_f_offset + be->be_length) - isect;
> - if (be->be_state == PNFS_BLOCK_INVALID_DATA)
> - bl_mark_for_commit(be, isect, len); /* What if fails? */
> + if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
> + se = bl_pop_one_short_extent(be->be_inval);
> + BUG_ON(!se);
> + bl_mark_for_commit(be, isect, len, se);
> + }
> isect += len;
> bl_put_extent(be);
> }
> @@ -347,7 +353,8 @@ static void bl_end_io_write_zero(struct bio *bio, int err)
> end_page_writeback(page);
> page_cache_release(page);
> } while (bvec >= bio->bi_io_vec);
> - if (!uptodate) {
> +
> + if (unlikely(!uptodate)) {
> if (!wdata->pnfs_error)
> wdata->pnfs_error = -EIO;
> pnfs_set_lo_fail(wdata->lseg);
> @@ -356,7 +363,6 @@ static void bl_end_io_write_zero(struct bio *bio, int err)
> put_parallel(par);
> }
>
> -/* This is basically copied from mpage_end_io_read */
> static void bl_end_io_write(struct bio *bio, int err)
> {
> struct parallel_io *par = bio->bi_private;
> @@ -382,7 +388,7 @@ static void bl_write_cleanup(struct work_struct *work)
> dprintk("%s enter\n", __func__);
> task = container_of(work, struct rpc_task, u.tk_work);
> wdata = container_of(task, struct nfs_write_data, task);
> - if (!wdata->pnfs_error) {
> + if (likely(!wdata->pnfs_error)) {
> /* Marks for LAYOUTCOMMIT */
> mark_extents_written(BLK_LSEG2EXT(wdata->lseg),
> wdata->args.offset, wdata->args.count);
> @@ -391,10 +397,15 @@ static void bl_write_cleanup(struct work_struct *work)
> }
>
> /* Called when last of bios associated with a bl_write_pagelist call finishes */
> -static void bl_end_par_io_write(void *data)
> +static void bl_end_par_io_write(void *data, int num_se)
> {
> struct nfs_write_data *wdata = data;
>
> + if (unlikely(wdata->pnfs_error)) {
> + bl_free_short_extents(&BLK_LSEG2EXT(wdata->lseg)->bl_inval,
> + num_se);
> + }
> +
> wdata->task.tk_status = wdata->pnfs_error;
> wdata->verf.committed = NFS_FILE_SYNC;
> INIT_WORK(&wdata->task.u.tk_work, bl_write_cleanup);
> @@ -547,7 +558,7 @@ bl_write_pagelist(struct nfs_write_data *wdata, int sync)
> */
> par = alloc_parallel(wdata);
> if (!par)
> - return PNFS_NOT_ATTEMPTED;
> + goto out_mds;
> par->pnfs_callback = bl_end_par_io_write;
> /* At this point, have to be more careful with error handling */
>
> @@ -555,12 +566,15 @@ bl_write_pagelist(struct nfs_write_data *wdata, int sync)
> be = bl_find_get_extent(BLK_LSEG2EXT(wdata->lseg), isect, &cow_read);
> if (!be || !is_writable(be, isect)) {
> dprintk("%s no matching extents!\n", __func__);
> - wdata->pnfs_error = -EINVAL;
> - goto out;
> + goto out_mds;
> }
>
> /* First page inside INVALID extent */
> if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
> + if (likely(!bl_push_one_short_extent(be->be_inval)))
> + par->bse_count++;
> + else
> + goto out_mds;
> temp = offset >> PAGE_CACHE_SHIFT;
> npg_zero = do_div(temp, npg_per_block);
> isect = (sector_t) (((offset - npg_zero * PAGE_CACHE_SIZE) &
> @@ -598,6 +612,19 @@ fill_invalid_ext:
> wdata->pnfs_error = ret;
> goto out;
> }
> + if (likely(!bl_push_one_short_extent(be->be_inval)))
> + par->bse_count++;
> + else {
> + end_page_writeback(page);
> + page_cache_release(page);
> + wdata->pnfs_error = -ENOMEM;
> + goto out;
> + }
> + /* FIXME: This should be done in bi_end_io */
> + mark_extents_written(BLK_LSEG2EXT(wdata->lseg),
> + page->index << PAGE_CACHE_SHIFT,
> + PAGE_CACHE_SIZE);
> +
> bio = bl_add_page_to_bio(bio, npg_zero, WRITE,
> isect, page, be,
> bl_end_io_write_zero, par);
> @@ -606,10 +633,6 @@ fill_invalid_ext:
> bio = NULL;
> goto out;
> }
> - /* FIXME: This should be done in bi_end_io */
> - mark_extents_written(BLK_LSEG2EXT(wdata->lseg),
> - page->index << PAGE_CACHE_SHIFT,
> - PAGE_CACHE_SIZE);
> next_page:
> isect += PAGE_CACHE_SECTORS;
> extent_length -= PAGE_CACHE_SECTORS;
> @@ -633,6 +656,15 @@ next_page:
> wdata->pnfs_error = -EINVAL;
> goto out;
> }
> + if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
> + if (likely(!bl_push_one_short_extent(
> + be->be_inval)))
> + par->bse_count++;
> + else {
> + wdata->pnfs_error = -ENOMEM;
> + goto out;
> + }
> + }
> extent_length = be->be_length -
> (isect - be->be_f_offset);
> }
> @@ -680,6 +712,10 @@ out:
> bl_submit_bio(WRITE, bio);
> put_parallel(par);
> return PNFS_ATTEMPTED;
> +out_mds:
> + bl_put_extent(be);
> + kfree(par);
> + return PNFS_NOT_ATTEMPTED;
> }
>
> /* FIXME - range ignored */
> @@ -706,11 +742,17 @@ static void
> release_inval_marks(struct pnfs_inval_markings *marks)
> {
> struct pnfs_inval_tracking *pos, *temp;
> + struct pnfs_block_short_extent *se, *stemp;
>
> list_for_each_entry_safe(pos, temp, &marks->im_tree.mtt_stub, it_link) {
> list_del(&pos->it_link);
> kfree(pos);
> }
> +
> + list_for_each_entry_safe(se, stemp, &marks->im_extents, bse_node) {
> + list_del(&se->bse_node);
> + kfree(se);
> + }
> return;
> }
>
> diff --git a/fs/nfs/blocklayout/blocklayout.h b/fs/nfs/blocklayout/blocklayout.h
> index 60728ac..e31a2df 100644
> --- a/fs/nfs/blocklayout/blocklayout.h
> +++ b/fs/nfs/blocklayout/blocklayout.h
> @@ -70,6 +70,7 @@ struct pnfs_inval_markings {
> spinlock_t im_lock;
> struct my_tree im_tree; /* Sectors that need LAYOUTCOMMIT */
> sector_t im_block_size; /* Server blocksize in sectors */
> + struct list_head im_extents; /* Short extents for INVAL->RW conversion */
> };
>
> struct pnfs_inval_tracking {
> @@ -105,6 +106,7 @@ BL_INIT_INVAL_MARKS(struct pnfs_inval_markings *marks, sector_t blocksize)
> {
> spin_lock_init(&marks->im_lock);
> INIT_LIST_HEAD(&marks->im_tree.mtt_stub);
> + INIT_LIST_HEAD(&marks->im_extents);
> marks->im_block_size = blocksize;
> marks->im_tree.mtt_step_size = min((sector_t)PAGE_CACHE_SECTORS,
> blocksize);
> @@ -199,6 +201,11 @@ void clean_pnfs_block_layoutupdate(struct pnfs_block_layout *bl,
> int bl_add_merge_extent(struct pnfs_block_layout *bl,
> struct pnfs_block_extent *new);
> int bl_mark_for_commit(struct pnfs_block_extent *be,
> - sector_t offset, sector_t length);
> + sector_t offset, sector_t length,
> + struct pnfs_block_short_extent *new);
> +int bl_push_one_short_extent(struct pnfs_inval_markings *marks);
> +struct pnfs_block_short_extent *
> +bl_pop_one_short_extent(struct pnfs_inval_markings *marks);
> +void bl_free_short_extents(struct pnfs_inval_markings *marks, int num_to_free);
>
> #endif /* FS_NFS_NFS4BLOCKLAYOUT_H */
> diff --git a/fs/nfs/blocklayout/extents.c b/fs/nfs/blocklayout/extents.c
> index d0f52ed..db66e68 100644
> --- a/fs/nfs/blocklayout/extents.c
> +++ b/fs/nfs/blocklayout/extents.c
> @@ -369,20 +369,18 @@ static void add_to_commitlist(struct pnfs_block_layout *bl,
>
> /* Note the range described by offset, length is guaranteed to be contained
> * within be.
> + * new will be freed, either by this function or add_to_commitlist if they
> + * decide not to use it, or after LAYOUTCOMMIT uses it in the commitlist.
> */
> int bl_mark_for_commit(struct pnfs_block_extent *be,
> - sector_t offset, sector_t length)
> + sector_t offset, sector_t length,
> + struct pnfs_block_short_extent *new)
> {
> sector_t new_end, end = offset + length;
> - struct pnfs_block_short_extent *new;
> struct pnfs_block_layout *bl = container_of(be->be_inval,
> struct pnfs_block_layout,
> bl_inval);
>
> - new = kmalloc(sizeof(*new), GFP_NOFS);
> - if (!new)
> - return -ENOMEM;
> -
> mark_written_sectors(be->be_inval, offset, length);
> /* We want to add the range to commit list, but it must be
> * block-normalized, and verified that the normalized range has
> @@ -412,9 +410,6 @@ int bl_mark_for_commit(struct pnfs_block_extent *be,
> new->bse_mdev = be->be_mdev;
>
> spin_lock(&bl->bl_ext_lock);
> - /* new will be freed, either by add_to_commitlist if it decides not
> - * to use it, or after LAYOUTCOMMIT uses it in the commitlist.
> - */
> add_to_commitlist(bl, new);
> spin_unlock(&bl->bl_ext_lock);
> return 0;
> @@ -862,3 +857,52 @@ clean_pnfs_block_layoutupdate(struct pnfs_block_layout *bl,
> }
> }
> }
> +
> +int bl_push_one_short_extent(struct pnfs_inval_markings *marks)
> +{
> + struct pnfs_block_short_extent *new;
> +
> + new = kmalloc(sizeof(*new), GFP_NOFS);
> + if (unlikely(!new))
> + return -ENOMEM;
> +
> + spin_lock(&marks->im_lock);
> + list_add(&new->bse_node, &marks->im_extents);
> + spin_unlock(&marks->im_lock);
> +
> + return 0;
> +}
> +
> +struct pnfs_block_short_extent *
> +bl_pop_one_short_extent(struct pnfs_inval_markings *marks)
> +{
> + struct pnfs_block_short_extent *rv = NULL;
> +
> + spin_lock(&marks->im_lock);
> + if (!list_empty(&marks->im_extents)) {
> + rv = list_entry((&marks->im_extents)->next,
> + struct pnfs_block_short_extent, bse_node);
> + list_del_init(&rv->bse_node);
> + }
> + spin_unlock(&marks->im_lock);
> +
> + return rv;
> +}
> +
> +void bl_free_short_extents(struct pnfs_inval_markings *marks, int num_to_free)
> +{
> + struct pnfs_block_short_extent *se = NULL, *tmp;
> +
> + BUG_ON(num_to_free <= 0);
Why is it a bug if num_to_free is <= 0? Couldn't you do:
if (num_to_free <= 0)
return;
instead?
- Bryan
> +
> + spin_lock(&marks->im_lock);
> + list_for_each_entry_safe(se, tmp, &marks->im_extents, bse_node) {
> + list_del(&se->bse_node);
> + kfree(se);
> + if (--num_to_free == 0)
> + break;
> + }
> + spin_unlock(&marks->im_lock);
> +
> + BUG_ON(num_to_free > 0);
> +}
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
