From: "Darrick J. Wong" Subject: Re: [PATCH v2] jbd2: gate checksum calculations on crc driver presence, not sb flags Date: Sun, 4 Oct 2015 23:21:31 -0700 Message-ID: <20151005062131.GA29098@birch.djwong.org> References: <20151003034601.GN10390@birch.djwong.org> <56120E06.4040103@kyup.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Jan Kara , "Theodore Ts'o" , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, SiteGround Operations , linux-ext4 To: Nikolay Borisov Return-path: Content-Disposition: inline In-Reply-To: <56120E06.4040103@kyup.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Mon, Oct 05, 2015 at 08:43:34AM +0300, Nikolay Borisov wrote: > It is just me or am I not seeing this feature test helper in this patch ? > > On 10/03/2015 06:46 AM, Darrick J. Wong wrote: > > Change the journal's checksum functions to gate on whether or not the > > crc32c driver is loaded, and gate the loading on the superblock bits. > > This prevents a journal crash if someone loads a journal in no-csum > > mode and then randomizes the superblock, thus flipping on the feature > > bits. > > > > v2: Create a feature-test helper, use it everywhere. > > > > Tested-By: Nikolay Borisov > > Reported-by: Nikolay Borisov > > Signed-off-by: Darrick J. Wong > > --- > > fs/jbd2/journal.c | 6 +++--- > > include/linux/jbd2.h | 13 +++++++++---- > > 2 files changed, 12 insertions(+), 7 deletions(-) > > > > diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c > > index 8270fe9..00f7dbd 100644 > > --- a/fs/jbd2/journal.c > > +++ b/fs/jbd2/journal.c > > @@ -124,7 +124,7 @@ EXPORT_SYMBOL(__jbd2_debug); > > /* Checksumming functions */ > > static int jbd2_verify_csum_type(journal_t *j, journal_superblock_t *sb) > > { > > - if (!jbd2_journal_has_csum_v2or3(j)) > > + if (!jbd2_journal_has_csum_v2or3_feature(j)) > > return 1; > > > > return sb->s_checksum_type == JBD2_CRC32C_CHKSUM; > > @@ -1531,7 +1531,7 @@ static int journal_get_superblock(journal_t *journal) > > goto out; > > } > > > > - if (jbd2_journal_has_csum_v2or3(journal) && > > + if (jbd2_journal_has_csum_v2or3_feature(journal) && > > JBD2_HAS_COMPAT_FEATURE(journal, JBD2_FEATURE_COMPAT_CHECKSUM)) { > > /* Can't have checksum v1 and v2 on at the same time! */ > > printk(KERN_ERR "JBD2: Can't enable checksumming v1 and v2/3 " > > @@ -1545,7 +1545,7 @@ static int journal_get_superblock(journal_t *journal) > > } > > > > /* Load the checksum driver */ > > - if (jbd2_journal_has_csum_v2or3(journal)) { > > + if (jbd2_journal_has_csum_v2or3_feature(journal)) { > > journal->j_chksum_driver = crypto_alloc_shash("crc32c", 0, 0); > > if (IS_ERR(journal->j_chksum_driver)) { > > printk(KERN_ERR "JBD2: Cannot load crc32c driver.\n"); > > diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h > > index df07e78..6da6f89 100644 > > --- a/include/linux/jbd2.h > > +++ b/include/linux/jbd2.h > > @@ -1338,13 +1338,18 @@ static inline int tid_geq(tid_t x, tid_t y) > > extern int jbd2_journal_blocks_per_page(struct inode *inode); > > extern size_t journal_tag_bytes(journal_t *journal); > > > > +static inline bool jbd2_journal_has_csum_v2or3_feature(journal_t *j) Here ^^^^^^^^^^^^^^^ --D > > +{ > > + return JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2) || > > + JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V3); > > +} > > + > > static inline int jbd2_journal_has_csum_v2or3(journal_t *journal) > > { > > - if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2) || > > - JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V3)) > > - return 1; > > + WARN_ON_ONCE(jbd2_journal_has_csum_v2or3_feature(journal) && > > + journal->j_chksum_driver == NULL); > > > > - return 0; > > + return journal->j_chksum_driver != NULL; > > } > > > > /* > >