Staging: Fixed pohmelfs regression because of per-bdi writeback.

commit 182374a0bddeef46769d2f8ab56fcccc433b96f3 upstream.

Since pohmelfs isn't tied to a single block device, it needs to setup a
backing dev like nfs/btrfs/etc do.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 21 insertions, 2 deletions

diff --git a/drivers/staging/pohmelfs/inode.c b/drivers/staging/pohmelfs/inode.c
index f69b7783027f..cd2581107607 100644
--- a/drivers/staging/pohmelfs/inode.c
+++ b/drivers/staging/pohmelfs/inode.c
@@ -36,6 +36,7 @@
 #define POHMELFS_MAGIC_NUM      0x504f482e
 
 static struct kmem_cache *pohmelfs_inode_cache;
+static atomic_t psb_bdi_num = ATOMIC_INIT(0);
 
 /*
  * Removes inode from all trees, drops local name cache and removes all queued
@@ -1331,6 +1332,8 @@ static void pohmelfs_put_super(struct super_block *sb)
         pohmelfs_crypto_exit(psb);
         pohmelfs_state_exit(psb);
 
+        bdi_destroy(&psb->bdi);
+
         kfree(psb);
         sb->s_fs_info = NULL;
 }
@@ -1815,11 +1818,22 @@ static int pohmelfs_fill_super(struct super_block *sb, void *data, int silent)
         if (!psb)
                 goto err_out_exit;
 
+        err = bdi_init(&psb->bdi);
+        if (err)
+                goto err_out_free_sb;
+
+        err = bdi_register(&psb->bdi, NULL, "pfs-%d", atomic_inc_return(&psb_bdi_num));
+        if (err) {
+                bdi_destroy(&psb->bdi);
+                goto err_out_free_sb;
+        }
+
         sb->s_fs_info = psb;
         sb->s_op = &pohmelfs_sb_ops;
         sb->s_magic = POHMELFS_MAGIC_NUM;
         sb->s_maxbytes = MAX_LFS_FILESIZE;
         sb->s_blocksize = PAGE_SIZE;
+        sb->s_bdi = &psb->bdi;
 
         psb->sb = sb;
 
@@ -1863,11 +1877,11 @@ static int pohmelfs_fill_super(struct super_block *sb, void *data, int silent)
 
         err = pohmelfs_parse_options((char *) data, psb, 0);
         if (err)
-                goto err_out_free_sb;
+                goto err_out_free_bdi;
 
         err = pohmelfs_copy_crypto(psb);
         if (err)
-                goto err_out_free_sb;
+                goto err_out_free_bdi;
 
         err = pohmelfs_state_init(psb);
         if (err)
@@ -1916,6 +1930,8 @@ err_out_state_exit:
 err_out_free_strings:
         kfree(psb->cipher_string);
         kfree(psb->hash_string);
+err_out_free_bdi:
+        bdi_destroy(&psb->bdi);
 err_out_free_sb:
         kfree(psb);
 err_out_exit:
diff --git a/drivers/staging/pohmelfs/netfs.h b/drivers/staging/pohmelfs/netfs.h
index 623a07d29dea..01cba006e07a 100644
--- a/drivers/staging/pohmelfs/netfs.h
+++ b/drivers/staging/pohmelfs/netfs.h
@@ -18,6 +18,7 @@
 
 #include <linux/types.h>
 #include <linux/connector.h>
+#include <linux/backing-dev.h>
 
 #define POHMELFS_CN_IDX                 5
 #define POHMELFS_CN_VAL                 0
@@ -624,6 +625,8 @@ struct pohmelfs_sb {
 
         struct super_block      *sb;
 
+        struct backing_dev_info bdi;
+
         /*
          * Algorithm strings.
          */