On Thu, 13 Jul 2017, Eric Wheeler wrote:

Tang,

Please resend.  This patch seems to be malformed.

Hi Tang,

This is an important bugfix since v4.10, can you get a clean patch sent to 
the list?

Michael, if Tang can get this in on time, can this squeeze this into v4.14 
before the rc's run out?


--
Eric Wheeler

--
Eric Wheeler

On Thu, 6 Jul 2017, tang.junhui@zte.com.cn wrote:

quoted

From: Tang Junhui <redacted>

bcache called ida_simple_remove() with minor which have multiplied by
BCACHE_MINORS, it would cause minor wrong release and leakage.

In addition, when adding partition support to bcache, the name assignment
was not updated, resulting in numbers jumping (bcache0, bcache16,
bcache32...). This has been fixed implicitly by the rework.

Signed-off-by: tang.junhui <redacted>
Reviewed-by: Coly Li <redacted>
Reviewed-by: Eric Wheeler <redacted>
Cc: stable@vger.kernel.org # 4.10
Cc: Stefan Bader <redacted>
Fixes: b8c0d91 (bcache: partition support: add 16 minors per bcacheN device)
BugLink: https://bugs.launchpad.net/bugs/1667078
---
 drivers/md/bcache/bcache.h | 12 ++++++++++++
 drivers/md/bcache/super.c  | 10 ++++------
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index c3ea03c..54f9075 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h

@@ -212,6 +212,10 @@ BITMASK(GC_MARK,         struct bucket, gc_mark, 0, 2);

 #define MAX_GC_SECTORS_USED        (~(~0ULL << GC_SECTORS_USED_SIZE))
 BITMASK(GC_SECTORS_USED, struct bucket, gc_mark, 2, GC_SECTORS_USED_SIZE);
 BITMASK(GC_MOVE, struct bucket, gc_mark, 15, 1);
+#define BCACHE_MINORS_BITS                4 /* bcache partition support */
+#define BCACHE_MINORS                     (1 << BCACHE_MINORS_BITS)
+#define BCACHE_MINOR_TO_IDA                                0
+#define IDA_MINOR_TO_BCACHE                                1
 
 #include "journal.h"
 #include "stats.h"

@@ -751,6 +755,14 @@ static inline bool ptr_available(struct cache_set *c, const struct bkey *k,

         return (PTR_DEV(k, i) < MAX_CACHES_PER_SET) && PTR_CACHE(c, k, i);
 }
 
+static inline int convert_minor(int minor, int style)
+{
+        if(style == BCACHE_MINOR_TO_IDA)
+                return (minor) >> BCACHE_MINORS_BITS;
+        else
+                return  (minor) << BCACHE_MINORS_BITS;
+}
+
 /* Btree key macros */
 
 /*

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 3a19cbc..6485afe 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c

@@ -57,8 +57,7 @@ static DEFINE_IDA(bcache_minor);

 static wait_queue_head_t unregister_wait;
 struct workqueue_struct *bcache_wq;
 
-#define BTREE_MAX_PAGES                (256 * 1024 / PAGE_SIZE)
-#define BCACHE_MINORS                16 /* partition support */
+#define BTREE_MAX_PAGES                          (256 * 1024 / PAGE_SIZE)
 
 /* Superblock */
 

@@ -734,7 +733,7 @@ static void bcache_device_free(struct bcache_device *d)

         if (d->disk && d->disk->queue)
                 blk_cleanup_queue(d->disk->queue);
         if (d->disk) {
-                ida_simple_remove(&bcache_minor, d->disk->first_minor);
+                ida_simple_remove(&bcache_minor, convert_minor(d->disk->first_minor, BCACHE_MINOR_TO_IDA));
                 put_disk(d->disk);
         }
 

@@ -780,11 +779,10 @@ static int bcache_device_init(struct bcache_device *d, unsigned block_size,

         if (!d->full_dirty_stripes)
                 return -ENOMEM;
 
-        minor = ida_simple_get(&bcache_minor, 0, MINORMASK + 1, GFP_KERNEL);
+        minor = ida_simple_get(&bcache_minor, 0, convert_minor(MINORMASK, BCACHE_MINOR_TO_IDA) + 1, GFP_KERNEL);
         if (minor < 0)
                 return minor;
 
-        minor *= BCACHE_MINORS;
 
         if (!(d->bio_split = bioset_create(4, offsetof(struct bbio, bio))) ||
             !(d->disk = alloc_disk(BCACHE_MINORS))) {

@@ -796,7 +794,7 @@ static int bcache_device_init(struct bcache_device *d, unsigned block_size,

         snprintf(d->disk->disk_name, DISK_NAME_LEN, "bcache%i", minor);
 
         d->disk->major                = bcache_major;
-        d->disk->first_minor        = minor;
+        d->disk->first_minor        = convert_minor(minor, IDA_MINOR_TO_BCACHE);
         d->disk->fops                = &bcache_ops;
         d->disk->private_data        = d;
 
--
2.8.1.windows.1