md: convert to kvmalloc

The code really just wants a big flat buffer, so just do that.

Link: http://lkml.kernel.org/r/20181217131929.11727-3-kent.overstreet@gmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

diff --git a/drivers/md/raid5-ppl.c b/drivers/md/raid5-ppl.c
index 3a7c363..0b096dd 100644 (file)
--- a/drivers/md/raid5-ppl.c
+++ b/drivers/md/raid5-ppl.c
@@ -16,7 +16,6 @@
 #include <linux/blkdev.h>
 #include <linux/slab.h>
 #include <linux/crc32c.h>
-#include <linux/flex_array.h>
 #include <linux/async_tx.h>
 #include <linux/raid/md_p.h>
 #include "md.h"
@@ -165,7 +164,7 @@ ops_run_partial_parity(struct stripe_head *sh, struct raid5_percpu *percpu,
                       struct dma_async_tx_descriptor *tx)
 {
        int disks = sh->disks;
-       struct page **srcs = flex_array_get(percpu->scribble, 0);
+       struct page **srcs = percpu->scribble;
        int count = 0, pd_idx = sh->pd_idx, i;
        struct async_submit_ctl submit;
 
@@ -196,8 +195,7 @@ ops_run_partial_parity(struct stripe_head *sh, struct raid5_percpu *percpu,
        }
 
        init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, tx,
-                         NULL, sh, flex_array_get(percpu->scribble, 0)
-                         + sizeof(struct page *) * (sh->disks + 2));
+                         NULL, sh, (void *) (srcs + sh->disks + 2));
 
        if (count == 1)
                tx = async_memcpy(sh->ppl_page, srcs[0], 0, 0, PAGE_SIZE,

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index cecea90..77ffd09 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -54,7 +54,6 @@
 #include <linux/slab.h>
 #include <linux/ratelimit.h>
 #include <linux/nodemask.h>
-#include <linux/flex_array.h>
 
 #include <trace/events/block.h>
 #include <linux/list_sort.h>
@@ -1394,22 +1393,16 @@ static void ops_complete_compute(void *stripe_head_ref)
 }
 
 /* return a pointer to the address conversion region of the scribble buffer */
-static addr_conv_t *to_addr_conv(struct stripe_head *sh,
-                                struct raid5_percpu *percpu, int i)
+static struct page **to_addr_page(struct raid5_percpu *percpu, int i)
 {
-       void *addr;
-
-       addr = flex_array_get(percpu->scribble, i);
-       return addr + sizeof(struct page *) * (sh->disks + 2);
+       return percpu->scribble + i * percpu->scribble_obj_size;
 }
 
 /* return a pointer to the address conversion region of the scribble buffer */
-static struct page **to_addr_page(struct raid5_percpu *percpu, int i)
+static addr_conv_t *to_addr_conv(struct stripe_head *sh,
+                                struct raid5_percpu *percpu, int i)
 {
-       void *addr;
-
-       addr = flex_array_get(percpu->scribble, i);
-       return addr;
+       return (void *) (to_addr_page(percpu, i) + sh->disks + 2);
 }
 
 static struct dma_async_tx_descriptor *
@@ -2238,21 +2231,23 @@ static int grow_stripes(struct r5conf *conf, int num)
  * calculate over all devices (not just the data blocks), using zeros in place
  * of the P and Q blocks.
  */
-static struct flex_array *scribble_alloc(int num, int cnt, gfp_t flags)
+static int scribble_alloc(struct raid5_percpu *percpu,
+                         int num, int cnt, gfp_t flags)
 {
-       struct flex_array *ret;
-       size_t len;
+       size_t obj_size =
+               sizeof(struct page *) * (num+2) +
+               sizeof(addr_conv_t) * (num+2);
+       void *scribble;
 
-       len = sizeof(struct page *) * (num+2) + sizeof(addr_conv_t) * (num+2);
-       ret = flex_array_alloc(len, cnt, flags);
-       if (!ret)
-               return NULL;
-       /* always prealloc all elements, so no locking is required */
-       if (flex_array_prealloc(ret, 0, cnt, flags)) {
-               flex_array_free(ret);
-               return NULL;
-       }
-       return ret;
+       scribble = kvmalloc_array(cnt, obj_size, flags);
+       if (!scribble)
+               return -ENOMEM;
+
+       kvfree(percpu->scribble);
+
+       percpu->scribble = scribble;
+       percpu->scribble_obj_size = obj_size;
+       return 0;
 }
 
 static int resize_chunks(struct r5conf *conf, int new_disks, int new_sectors)
@@ -2270,23 +2265,18 @@ static int resize_chunks(struct r5conf *conf, int new_disks, int new_sectors)
                return 0;
        mddev_suspend(conf->mddev);
        get_online_cpus();
+
        for_each_present_cpu(cpu) {
                struct raid5_percpu *percpu;
-               struct flex_array *scribble;
 
                percpu = per_cpu_ptr(conf->percpu, cpu);
-               scribble = scribble_alloc(new_disks,
-                                         new_sectors / STRIPE_SECTORS,
-                                         GFP_NOIO);
-
-               if (scribble) {
-                       flex_array_free(percpu->scribble);
-                       percpu->scribble = scribble;
-               } else {
-                       err = -ENOMEM;
+               err = scribble_alloc(percpu, new_disks,
+                                    new_sectors / STRIPE_SECTORS,
+                                    GFP_NOIO);
+               if (err)
                        break;
-               }
        }
+
        put_online_cpus();
        mddev_resume(conf->mddev);
        if (!err) {
@@ -6742,25 +6732,26 @@ raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks)
 static void free_scratch_buffer(struct r5conf *conf, struct raid5_percpu *percpu)
 {
        safe_put_page(percpu->spare_page);
-       if (percpu->scribble)
-               flex_array_free(percpu->scribble);
        percpu->spare_page = NULL;
+       kvfree(percpu->scribble);
        percpu->scribble = NULL;
 }
 
 static int alloc_scratch_buffer(struct r5conf *conf, struct raid5_percpu *percpu)
 {
-       if (conf->level == 6 && !percpu->spare_page)
+       if (conf->level == 6 && !percpu->spare_page) {
                percpu->spare_page = alloc_page(GFP_KERNEL);
-       if (!percpu->scribble)
-               percpu->scribble = scribble_alloc(max(conf->raid_disks,
-                                                     conf->previous_raid_disks),
-                                                 max(conf->chunk_sectors,
-                                                     conf->prev_chunk_sectors)
-                                                  / STRIPE_SECTORS,
-                                                 GFP_KERNEL);
-
-       if (!percpu->scribble || (conf->level == 6 && !percpu->spare_page)) {
+               if (!percpu->spare_page)
+                       return -ENOMEM;
+       }
+
+       if (scribble_alloc(percpu,
+                          max(conf->raid_disks,
+                              conf->previous_raid_disks),
+                          max(conf->chunk_sectors,
+                              conf->prev_chunk_sectors)
+                          / STRIPE_SECTORS,
+                          GFP_KERNEL)) {
                free_scratch_buffer(conf, percpu);
                return -ENOMEM;
        }

diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index 8474c22..cf991f1 100644 (file)
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -638,10 +638,11 @@ struct r5conf {
        /* per cpu variables */
        struct raid5_percpu {
                struct page     *spare_page; /* Used when checking P/Q in raid6 */
-               struct flex_array *scribble;   /* space for constructing buffer
-                                             * lists and performing address
-                                             * conversions
-                                             */
+               void            *scribble;  /* space for constructing buffer
+                                            * lists and performing address
+                                            * conversions
+                                            */
+               int scribble_obj_size;
        } __percpu *percpu;
        int scribble_disks;
        int scribble_sectors;