On Tue, Dec 29 2009, Rafael J. Wysocki wrote: > On Tuesday 29 December 2009, Evgeniy Polyakov wrote: > > On Tue, Dec 29, 2009 at 04:28:52PM +0100, Rafael J. Wysocki (rjw@xxxxxxx) wrote: > > > This message has been generated automatically as a part of a report > > > of regressions introduced between 2.6.31 and 2.6.32. > > > > > > The following bug entry is on the current list of known regressions > > > introduced between 2.6.31 and 2.6.32. Please verify if it still should > > > be listed and let me know (either way). > > > > > > > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=14894 > > > Subject : pohmelfs: NULL pointer dereference > > > Submitter : Alexander Beregalov <a.beregalov@xxxxxxxxx> > > > Date : 2009-12-02 1:11 (28 days old) > > > References : http://marc.info/?l=linux-kernel&m=125971633107940&w=4 > > > Handled-By : Evgeniy Polyakov <zbr@xxxxxxxxxxx> > > > > Yes, I saw this regression and there is a patch to handle this, but it > > kind of disables sync at all. Jens Axboe, who introduced per-bdi > > writeback patches, did not yet reply. > > Well, Jens, what's your opinion about that? Since pohmelfs isn't tied to a single block device, it needs to setup a backing dev like nfs/btrfs/etc do. Here's a completely untested patch. diff --git a/drivers/staging/pohmelfs/inode.c b/drivers/staging/pohmelfs/inode.c index f69b778..cd25811 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 623a07d..01cba00 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. */ -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
