[PATCH v2 10/17] UBI: move the global ech and vidh variables into struct ubi_attach_info

From: Boris Brezillon
Date: Mon Sep 05 2016 - 11:05:31 EST


Even if it works fine with those global variables, attaching the
temporary ech and vidh objects used during UBI scan to the
ubi_attach_info object sounds like a more future-proof option.

For example, attaching several UBI devices in parallel is prevented by
this use of global variable. And also because global variables should
be avoided in general.

Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
---
drivers/mtd/ubi/attach.c | 39 +++++++++++++++++++--------------------
drivers/mtd/ubi/ubi.h | 4 ++++
2 files changed, 23 insertions(+), 20 deletions(-)

diff --git a/drivers/mtd/ubi/attach.c b/drivers/mtd/ubi/attach.c
index 82b30c959a28..507f5d6b6114 100644
--- a/drivers/mtd/ubi/attach.c
+++ b/drivers/mtd/ubi/attach.c
@@ -91,10 +91,6 @@

static int self_check_ai(struct ubi_device *ubi, struct ubi_attach_info *ai);

-/* Temporary variables used during scanning */
-static struct ubi_ec_hdr *ech;
-static struct ubi_vid_hdr *vidh;
-
#define AV_FIND BIT(0)
#define AV_ADD BIT(1)
#define AV_FIND_OR_ADD (AV_FIND | AV_ADD)
@@ -958,6 +954,8 @@ static bool vol_ignored(int vol_id)
static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
int pnum, bool fast)
{
+ struct ubi_ec_hdr *ech = ai->ech;
+ struct ubi_vid_hdr *vidh = ai->vidh;
long long ec;
int err, bitflips = 0, vol_id = -1, ec_err = 0;

@@ -1394,12 +1392,12 @@ static int scan_all(struct ubi_device *ubi, struct ubi_attach_info *ai,

err = -ENOMEM;

- ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
- if (!ech)
+ ai->ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
+ if (!ai->ech)
return err;

- vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
- if (!vidh)
+ ai->vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
+ if (!ai->vidh)
goto out_ech;

for (pnum = start; pnum < ubi->peb_count; pnum++) {
@@ -1448,15 +1446,15 @@ static int scan_all(struct ubi_device *ubi, struct ubi_attach_info *ai,
if (err)
goto out_vidh;

- ubi_free_vid_hdr(ubi, vidh);
- kfree(ech);
+ ubi_free_vid_hdr(ubi, ai->vidh);
+ kfree(ai->ech);

return 0;

out_vidh:
- ubi_free_vid_hdr(ubi, vidh);
+ ubi_free_vid_hdr(ubi, ai->vidh);
out_ech:
- kfree(ech);
+ kfree(ai->ech);
return err;
}

@@ -1508,12 +1506,12 @@ static int scan_fast(struct ubi_device *ubi, struct ubi_attach_info **ai)
if (!scan_ai)
goto out;

- ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
- if (!ech)
+ scan_ai->ech = kzalloc(ubi->ec_hdr_alsize, GFP_KERNEL);
+ if (!scan_ai->ech)
goto out_ai;

- vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
- if (!vidh)
+ scan_ai->vidh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
+ if (!scan_ai->vidh)
goto out_ech;

for (pnum = 0; pnum < UBI_FM_MAX_START; pnum++) {
@@ -1525,8 +1523,8 @@ static int scan_fast(struct ubi_device *ubi, struct ubi_attach_info **ai)
goto out_vidh;
}

- ubi_free_vid_hdr(ubi, vidh);
- kfree(ech);
+ ubi_free_vid_hdr(ubi, scan_ai->vidh);
+ kfree(scan_ai->ech);

if (scan_ai->force_full_scan)
err = UBI_NO_FASTMAP;
@@ -1546,9 +1544,9 @@ static int scan_fast(struct ubi_device *ubi, struct ubi_attach_info **ai)
return err;

out_vidh:
- ubi_free_vid_hdr(ubi, vidh);
+ ubi_free_vid_hdr(ubi, scan_ai->vidh);
out_ech:
- kfree(ech);
+ kfree(scan_ai->ech);
out_ai:
destroy_ai(scan_ai);
out:
@@ -1670,6 +1668,7 @@ out_ai:
*/
static int self_check_ai(struct ubi_device *ubi, struct ubi_attach_info *ai)
{
+ struct ubi_vid_hdr *vidh = ai->vidh;
int pnum, err, vols_found = 0;
struct rb_node *rb1, *rb2;
struct ubi_ainf_volume *av;
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index f22c6c2e980f..b51d398f2356 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -724,6 +724,8 @@ struct ubi_ainf_volume {
* @ec_sum: a temporary variable used when calculating @mean_ec
* @ec_count: a temporary variable used when calculating @mean_ec
* @aeb_slab_cache: slab cache for &struct ubi_ainf_peb objects
+ * @ech: temporary EC header. Only available during scan
+ * @vidh: temporary VID header. Only available during scan
*
* This data structure contains the result of attaching an MTD device and may
* be used by other UBI sub-systems to build final UBI data structures, further
@@ -752,6 +754,8 @@ struct ubi_attach_info {
uint64_t ec_sum;
int ec_count;
struct kmem_cache *aeb_slab_cache;
+ struct ubi_ec_hdr *ech;
+ struct ubi_vid_hdr *vidh;
};

/**
--
2.7.4