From: Jeff Layton <firstname.lastname@example.org> To: Lu Fengqi <email@example.com>, firstname.lastname@example.org Cc: email@example.com, "Darrick J. Wong" <firstname.lastname@example.org> Subject: Re: [PATCH] inode: always initialize mapping->wb_err Date: Sat, 26 May 2018 07:42:46 -0400 [thread overview] Message-ID: <email@example.com> (raw) In-Reply-To: <firstname.lastname@example.org> On Sat, 2018-05-26 at 10:42 +0800, Lu Fengqi wrote: > Creating a file reuses the inode object by kmem_cache_alloc without > initializing maping->wb_err. If it contains an unseen writeback error, > fsync will report an error on the file, even if no error has ever occurred > after the file was created. > > Before commit b4678df184b3 ("errseq: Always report a writeback error > once"), any errors that occur before the file descriptor is opened will be > ignored, causing the issue not to be found. Afterward, any unseen writeback > error will be reported once, including, of course, the uninitialized > maping->wb_err, which exposes this problem. > > Signed-off-by: Lu Fengqi <email@example.com> > --- > fs/inode.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/fs/inode.c b/fs/inode.c > index 13ceb98c3bd3..bf02dc9d1837 100644 > --- a/fs/inode.c > +++ b/fs/inode.c > @@ -182,6 +182,7 @@ int inode_init_always(struct super_block *sb, struct inode *inode) > mapping_set_gfp_mask(mapping, GFP_HIGHUSER_MOVABLE); > mapping->private_data = NULL; > mapping->writeback_index = 0; > + mapping->wb_err = 0; > inode->i_private = NULL; > inode->i_mapping = mapping; > INIT_HLIST_HEAD(&inode->i_dentry); /* buggered by rcu freeing */ (cc'ing Darrick) I think Darrick had a similar patch that also fixed up some related inode reuse issues in xfs. Darrick, were you planning to get that merged for v4.17? -- Jeff Layton <firstname.lastname@example.org>
next prev parent reply other threads:[~2018-05-26 11:42 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-05-26 2:42 Lu Fengqi 2018-05-26 11:42 ` Jeff Layton [this message] 2018-05-26 12:29 ` Lu Fengqi 2018-05-29 17:49 ` Darrick J. Wong
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