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Date: Mon, 21 Jan 2013 14:21:30 +0900
From: Minchan Kim <minchan@...nel.org>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: linux-mm@...ck.org, linux-kernel@...r.kernel.org,
Nitin Gupta <ngupta@...are.org>,
Seth Jennings <sjenning@...ux.vnet.ibm.com>,
Konrad Rzeszutek Wilk <konrad@...nok.org>,
Dan Magenheimer <dan.magenheimer@...cle.com>,
Pekka Enberg <penberg@...helsinki.fi>, jmarchan@...hat.com,
Minchan Kim <minchan@...nel.org>
Subject: [PATCH v3 3/4] zram: get rid of lockdep warning
Lockdep complains about recursive deadlock of zram->init_lock.
[1] made it false positive because we can't request IO to zram
before setting disksize. Anyway, we should shut lockdep up to
avoid many reporting from user.
Cc: Jerome Marchand <jmarchan@...hat.com>
Cc: Nitin Gupta <ngupta@...are.org>
Signed-off-by: Minchan Kim <minchan@...nel.org>
---
drivers/staging/zram/zram_drv.c | 115 +++++++++++++++++++------------------
drivers/staging/zram/zram_drv.h | 12 +++-
drivers/staging/zram/zram_sysfs.c | 10 +++-
3 files changed, 79 insertions(+), 58 deletions(-)
diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c
index e95e37c..1f6938a 100644
--- a/drivers/staging/zram/zram_drv.c
+++ b/drivers/staging/zram/zram_drv.c
@@ -462,19 +462,12 @@ error:
void __zram_reset_device(struct zram *zram)
{
size_t index;
+ struct zram_meta meta;
if (!zram->init_done)
goto out;
zram->init_done = 0;
-
- /* Free various per-device buffers */
- kfree(zram->compress_workmem);
- free_pages((unsigned long)zram->compress_buffer, 1);
-
- zram->compress_workmem = NULL;
- zram->compress_buffer = NULL;
-
/* Free all pages that are still in this zram device */
for (index = 0; index < zram->disksize >> PAGE_SHIFT; index++) {
unsigned long handle = zram->table[index].handle;
@@ -484,11 +477,11 @@ void __zram_reset_device(struct zram *zram)
zs_free(zram->mem_pool, handle);
}
- vfree(zram->table);
- zram->table = NULL;
-
- zs_destroy_pool(zram->mem_pool);
- zram->mem_pool = NULL;
+ meta.compress_workmem = zram->compress_workmem;
+ meta.compress_buffer = zram->compress_buffer;
+ meta.table = zram->table;
+ meta.mem_pool = zram->mem_pool;
+ zram_meta_free(&meta);
/* Reset stats */
memset(&zram->stats, 0, sizeof(zram->stats));
@@ -505,12 +498,59 @@ void zram_reset_device(struct zram *zram)
up_write(&zram->init_lock);
}
-/* zram->init_lock should be held */
-int zram_init_device(struct zram *zram)
+void zram_meta_free(struct zram_meta *meta)
+{
+ zs_destroy_pool(meta->mem_pool);
+ kfree(meta->compress_workmem);
+ free_pages((unsigned long)meta->compress_buffer, 1);
+ vfree(meta->table);
+ kfree(meta);
+}
+
+int zram_meta_alloc(struct zram_meta *meta, u64 disksize)
{
- int ret;
size_t num_pages;
+ meta->compress_workmem = kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL);
+ if (!meta->compress_workmem) {
+ pr_err("Error allocating compressor working memory!\n");
+ goto out;
+ }
+
+ meta->compress_buffer =
+ (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 1);
+ if (!meta->compress_buffer) {
+ pr_err("Error allocating compressor buffer space\n");
+ goto free_workmem;
+ }
+
+ num_pages = disksize >> PAGE_SHIFT;
+ meta->table = vzalloc(num_pages * sizeof(*meta->table));
+ if (!meta->table) {
+ pr_err("Error allocating zram address table\n");
+ goto free_buffer;
+ }
+
+ meta->mem_pool = zs_create_pool("zram", GFP_NOIO | __GFP_HIGHMEM);
+ if (!meta->mem_pool) {
+ pr_err("Error creating memory pool\n");
+ goto free_table;
+ }
+
+ return 0;
+
+free_table:
+ vfree(meta->table);
+free_buffer:
+ free_pages((unsigned long)meta->compress_buffer, 1);
+free_workmem:
+ kfree(meta->compress_workmem);
+out:
+ return -ENOMEM;
+}
+
+void zram_init_device(struct zram *zram, struct zram_meta *meta)
+{
if (zram->disksize > 2 * (totalram_pages << PAGE_SHIFT)) {
pr_info(
"There is little point creating a zram of greater than "
@@ -525,51 +565,16 @@ int zram_init_device(struct zram *zram)
);
}
- zram->compress_workmem = kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL);
- if (!zram->compress_workmem) {
- pr_err("Error allocating compressor working memory!\n");
- ret = -ENOMEM;
- goto fail_no_table;
- }
-
- zram->compress_buffer =
- (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1);
- if (!zram->compress_buffer) {
- pr_err("Error allocating compressor buffer space\n");
- ret = -ENOMEM;
- goto fail_no_table;
- }
-
- num_pages = zram->disksize >> PAGE_SHIFT;
- zram->table = vzalloc(num_pages * sizeof(*zram->table));
- if (!zram->table) {
- pr_err("Error allocating zram address table\n");
- ret = -ENOMEM;
- goto fail_no_table;
- }
-
/* zram devices sort of resembles non-rotational disks */
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue);
- zram->mem_pool = zs_create_pool("zram", GFP_NOIO | __GFP_HIGHMEM);
- if (!zram->mem_pool) {
- pr_err("Error creating memory pool\n");
- ret = -ENOMEM;
- goto fail;
- }
-
+ zram->mem_pool = meta->mem_pool;
+ zram->compress_workmem = meta->compress_workmem;
+ zram->compress_buffer = meta->compress_buffer;
+ zram->table = meta->table;
zram->init_done = 1;
pr_debug("Initialization done!\n");
- return 0;
-
-fail_no_table:
- /* To prevent accessing table entries during cleanup */
- zram->disksize = 0;
-fail:
- __zram_reset_device(zram);
- pr_err("Initialization failed: err=%d\n", ret);
- return ret;
}
static void zram_slot_free_notify(struct block_device *bdev,
diff --git a/drivers/staging/zram/zram_drv.h b/drivers/staging/zram/zram_drv.h
index 5b671d1..fbe7db0 100644
--- a/drivers/staging/zram/zram_drv.h
+++ b/drivers/staging/zram/zram_drv.h
@@ -83,11 +83,19 @@ struct zram_stats {
u32 bad_compress; /* % of pages with compression ratio>=75% */
};
+struct zram_meta {
+ void *compress_workmem;
+ void *compress_buffer;
+ struct table *table;
+ struct zs_pool *mem_pool;
+};
+
struct zram {
struct zs_pool *mem_pool;
void *compress_workmem;
void *compress_buffer;
struct table *table;
+
spinlock_t stat64_lock; /* protect 64-bit stats */
struct rw_semaphore lock; /* protect compression buffers and table
* against concurrent read and writes */
@@ -111,7 +119,9 @@ unsigned int zram_get_num_devices(void);
extern struct attribute_group zram_disk_attr_group;
#endif
-extern int zram_init_device(struct zram *zram);
extern void zram_reset_device(struct zram *zram);
+extern int zram_meta_alloc(struct zram_meta *meta, u64 disksize);
+extern void zram_meta_free(struct zram_meta *meta);
+extern void zram_init_device(struct zram *zram, struct zram_meta *meta);
#endif
diff --git a/drivers/staging/zram/zram_sysfs.c b/drivers/staging/zram/zram_sysfs.c
index 369db12..31433ef 100644
--- a/drivers/staging/zram/zram_sysfs.c
+++ b/drivers/staging/zram/zram_sysfs.c
@@ -56,22 +56,28 @@ static ssize_t disksize_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t len)
{
u64 disksize;
+ struct zram_meta meta;
struct zram *zram = dev_to_zram(dev);
disksize = memparse(buf, NULL);
if (!disksize)
return -EINVAL;
+ disksize = PAGE_ALIGN(disksize);
+ if (zram_meta_alloc(&meta, disksize))
+ return -ENOMEM;
+
down_write(&zram->init_lock);
if (zram->init_done) {
up_write(&zram->init_lock);
+ zram_meta_free(&meta);
pr_info("Cannot change disksize for initialized device\n");
return -EBUSY;
}
- zram->disksize = PAGE_ALIGN(disksize);
+ zram->disksize = disksize;
set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT);
- zram_init_device(zram);
+ zram_init_device(zram, &meta);
up_write(&zram->init_lock);
return len;
--
1.7.9.5
--
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