zram: move comp allocation out of init_lock
While fixing lockdep spew of ->init_lock reported by Sasha Levin [1],
Minchan Kim noted [2] that it's better to move compression backend
allocation (using GPF_KERNEL) out of the ->init_lock lock, same way as
with zram_meta_alloc(), in order to prevent the same lockdep spew.
[1] https://lkml.org/lkml/2014/2/27/337
[2] https://lkml.org/lkml/2014/3/3/32
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reported-by: Minchan Kim <minchan@kernel.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit d61f98c70e8b0d324e8e83be2ed546d6295e63f3)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index f15564e..fe0daa9 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -579,9 +579,10 @@
struct device_attribute *attr, const char *buf, size_t len)
{
u64 disksize;
+ struct zcomp *comp;
struct zram_meta *meta;
struct zram *zram = dev_to_zram(dev);
- int err;
+ int err = -EINVAL;
disksize = memparse(buf, NULL);
if (!disksize)
@@ -592,30 +593,32 @@
if (!meta)
return -ENOMEM;
- down_write(&zram->init_lock);
- if (init_done(zram)) {
- pr_info("Cannot change disksize for initialized device\n");
- err = -EBUSY;
- goto out_free_meta;
- }
-
- zram->comp = zcomp_create(zram->compressor, zram->max_comp_streams);
- if (!zram->comp) {
+ comp = zcomp_create(zram->compressor, zram->max_comp_streams);
+ if (!comp) {
pr_info("Cannot initialise %s compressing backend\n",
zram->compressor);
- err = -EINVAL;
- goto out_free_meta;
+ goto out_cleanup;
+ }
+
+ down_write(&zram->init_lock);
+ if (init_done(zram)) {
+ up_write(&zram->init_lock);
+ pr_info("Cannot change disksize for initialized device\n");
+ err = -EBUSY;
+ goto out_cleanup;
}
zram->meta = meta;
+ zram->comp = comp;
zram->disksize = disksize;
set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT);
up_write(&zram->init_lock);
return len;
-out_free_meta:
- up_write(&zram->init_lock);
+out_cleanup:
+ if (comp)
+ zcomp_destroy(comp);
zram_meta_free(meta);
return err;
}