| Message ID | 4A3F3B32.9090606@gmail.com |
|---|---|
| State | Accepted, archived |
| Headers | show |
Ted, I don't think this got merged... Honza > resend this patch: > > At committing phase, we call jbd2_journal_write_metadata_buffer to > prepare log block's buffer_head, in this function, new_bh->b_data is set > to b_frozen_data or bh_in->b_data. We call "jbd_unlock_bh_state(bh_in)" > too early, since at this point , we haven't file bh_in to BJ_shadow > list, and we may set new_bh->b_data to bh_in->b_data, at this time, > another thread may call get write access of bh_in, modify bh_in->b_data > and dirty it. So , if new_bh->b_data is set to bh_in->b_data, the > committing transaction may flush the newly modified buffer content to > disk, preserve work done in jbd2_journal_get_write_access is useless. > jbd also has this problem. > > here is the patch based on kernel version 2.6.30: > > Signed-off-by: dingdinghua <dingdinghua@nrchpc.ac.cn> > Acked-by: Jan Kara <jack@suse.cz> > > --- > > diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c > index 737f724..ff5dcb5 100644 > --- a/fs/jbd/journal.c > +++ b/fs/jbd/journal.c > @@ -287,6 +287,7 @@ int journal_write_metadata_buffer(transaction_t *transaction, > struct page *new_page; > unsigned int new_offset; > struct buffer_head *bh_in = jh2bh(jh_in); > + journal_t *journal = transaction->t_journal; > > /* > * The buffer really shouldn't be locked: only the current committing > @@ -300,6 +301,11 @@ int journal_write_metadata_buffer(transaction_t *transaction, > J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in)); > > new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL); > + /* keep subsequent assertions sane */ > + new_bh->b_state = 0; > + init_buffer(new_bh, NULL, NULL); > + atomic_set(&new_bh->b_count, 1); > + new_jh = journal_add_journal_head(new_bh); /* This sleeps */ > > /* > * If a new transaction has already done a buffer copy-out, then > @@ -361,14 +367,6 @@ repeat: > kunmap_atomic(mapped_data, KM_USER0); > } > > - /* keep subsequent assertions sane */ > - new_bh->b_state = 0; > - init_buffer(new_bh, NULL, NULL); > - atomic_set(&new_bh->b_count, 1); > - jbd_unlock_bh_state(bh_in); > - > - new_jh = journal_add_journal_head(new_bh); /* This sleeps */ > - > set_bh_page(new_bh, new_page, new_offset); > new_jh->b_transaction = NULL; > new_bh->b_size = jh2bh(jh_in)->b_size; > @@ -385,7 +383,11 @@ repeat: > * copying is moved to the transaction's shadow queue. > */ > JBUFFER_TRACE(jh_in, "file as BJ_Shadow"); > - journal_file_buffer(jh_in, transaction, BJ_Shadow); > + spin_lock(&journal->j_list_lock); > + __journal_file_buffer(jh_in, transaction, BJ_Shadow); > + spin_unlock(&journal->j_list_lock); > + jbd_unlock_bh_state(bh_in); > + > JBUFFER_TRACE(new_jh, "file as BJ_IO"); > journal_file_buffer(new_jh, transaction, BJ_IO); > > diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c > index 18bfd5d..4a0b48f 100644 > --- a/fs/jbd2/journal.c > +++ b/fs/jbd2/journal.c > @@ -297,6 +297,8 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction, > unsigned int new_offset; > struct buffer_head *bh_in = jh2bh(jh_in); > struct jbd2_buffer_trigger_type *triggers; > + journal_t *journal = transaction->t_journal; > + > > /* > * The buffer really shouldn't be locked: only the current committing > @@ -310,6 +312,11 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction, > J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in)); > > new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL); > + /* keep subsequent assertions sane */ > + new_bh->b_state = 0; > + init_buffer(new_bh, NULL, NULL); > + atomic_set(&new_bh->b_count, 1); > + new_jh = jbd2_journal_add_journal_head(new_bh); /* This sleeps */ > > /* > * If a new transaction has already done a buffer copy-out, then > @@ -388,14 +395,6 @@ repeat: > kunmap_atomic(mapped_data, KM_USER0); > } > > - /* keep subsequent assertions sane */ > - new_bh->b_state = 0; > - init_buffer(new_bh, NULL, NULL); > - atomic_set(&new_bh->b_count, 1); > - jbd_unlock_bh_state(bh_in); > - > - new_jh = jbd2_journal_add_journal_head(new_bh); /* This sleeps */ > - > set_bh_page(new_bh, new_page, new_offset); > new_jh->b_transaction = NULL; > new_bh->b_size = jh2bh(jh_in)->b_size; > @@ -412,7 +411,11 @@ repeat: > * copying is moved to the transaction's shadow queue. > */ > JBUFFER_TRACE(jh_in, "file as BJ_Shadow"); > - jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow); > + spin_lock(&journal->j_list_lock); > + __jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow); > + spin_unlock(&journal->j_list_lock); > + jbd_unlock_bh_state(bh_in); > + > JBUFFER_TRACE(new_jh, "file as BJ_IO"); > jbd2_journal_file_buffer(new_jh, transaction, BJ_IO); > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
> Ted, I don't think this got merged... Ah, I see, jbd2 part got merged by you, I'm not sure about the jbd part since I didn't see Andrew reply. I guess I'll create a tree for ext3/jbd changes and merge this patch (and other ext3/jbd fixes I have here) through it. Honza > > resend this patch: > > > > At committing phase, we call jbd2_journal_write_metadata_buffer to > > prepare log block's buffer_head, in this function, new_bh->b_data is set > > to b_frozen_data or bh_in->b_data. We call "jbd_unlock_bh_state(bh_in)" > > too early, since at this point , we haven't file bh_in to BJ_shadow > > list, and we may set new_bh->b_data to bh_in->b_data, at this time, > > another thread may call get write access of bh_in, modify bh_in->b_data > > and dirty it. So , if new_bh->b_data is set to bh_in->b_data, the > > committing transaction may flush the newly modified buffer content to > > disk, preserve work done in jbd2_journal_get_write_access is useless. > > jbd also has this problem. > > > > here is the patch based on kernel version 2.6.30: > > > > Signed-off-by: dingdinghua <dingdinghua@nrchpc.ac.cn> > > Acked-by: Jan Kara <jack@suse.cz> > > > > --- > > > > diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c > > index 737f724..ff5dcb5 100644 > > --- a/fs/jbd/journal.c > > +++ b/fs/jbd/journal.c > > @@ -287,6 +287,7 @@ int journal_write_metadata_buffer(transaction_t *transaction, > > struct page *new_page; > > unsigned int new_offset; > > struct buffer_head *bh_in = jh2bh(jh_in); > > + journal_t *journal = transaction->t_journal; > > > > /* > > * The buffer really shouldn't be locked: only the current committing > > @@ -300,6 +301,11 @@ int journal_write_metadata_buffer(transaction_t *transaction, > > J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in)); > > > > new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL); > > + /* keep subsequent assertions sane */ > > + new_bh->b_state = 0; > > + init_buffer(new_bh, NULL, NULL); > > + atomic_set(&new_bh->b_count, 1); > > + new_jh = journal_add_journal_head(new_bh); /* This sleeps */ > > > > /* > > * If a new transaction has already done a buffer copy-out, then > > @@ -361,14 +367,6 @@ repeat: > > kunmap_atomic(mapped_data, KM_USER0); > > } > > > > - /* keep subsequent assertions sane */ > > - new_bh->b_state = 0; > > - init_buffer(new_bh, NULL, NULL); > > - atomic_set(&new_bh->b_count, 1); > > - jbd_unlock_bh_state(bh_in); > > - > > - new_jh = journal_add_journal_head(new_bh); /* This sleeps */ > > - > > set_bh_page(new_bh, new_page, new_offset); > > new_jh->b_transaction = NULL; > > new_bh->b_size = jh2bh(jh_in)->b_size; > > @@ -385,7 +383,11 @@ repeat: > > * copying is moved to the transaction's shadow queue. > > */ > > JBUFFER_TRACE(jh_in, "file as BJ_Shadow"); > > - journal_file_buffer(jh_in, transaction, BJ_Shadow); > > + spin_lock(&journal->j_list_lock); > > + __journal_file_buffer(jh_in, transaction, BJ_Shadow); > > + spin_unlock(&journal->j_list_lock); > > + jbd_unlock_bh_state(bh_in); > > + > > JBUFFER_TRACE(new_jh, "file as BJ_IO"); > > journal_file_buffer(new_jh, transaction, BJ_IO); > > > > diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c > > index 18bfd5d..4a0b48f 100644 > > --- a/fs/jbd2/journal.c > > +++ b/fs/jbd2/journal.c > > @@ -297,6 +297,8 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction, > > unsigned int new_offset; > > struct buffer_head *bh_in = jh2bh(jh_in); > > struct jbd2_buffer_trigger_type *triggers; > > + journal_t *journal = transaction->t_journal; > > + > > > > /* > > * The buffer really shouldn't be locked: only the current committing > > @@ -310,6 +312,11 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction, > > J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in)); > > > > new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL); > > + /* keep subsequent assertions sane */ > > + new_bh->b_state = 0; > > + init_buffer(new_bh, NULL, NULL); > > + atomic_set(&new_bh->b_count, 1); > > + new_jh = jbd2_journal_add_journal_head(new_bh); /* This sleeps */ > > > > /* > > * If a new transaction has already done a buffer copy-out, then > > @@ -388,14 +395,6 @@ repeat: > > kunmap_atomic(mapped_data, KM_USER0); > > } > > > > - /* keep subsequent assertions sane */ > > - new_bh->b_state = 0; > > - init_buffer(new_bh, NULL, NULL); > > - atomic_set(&new_bh->b_count, 1); > > - jbd_unlock_bh_state(bh_in); > > - > > - new_jh = jbd2_journal_add_journal_head(new_bh); /* This sleeps */ > > - > > set_bh_page(new_bh, new_page, new_offset); > > new_jh->b_transaction = NULL; > > new_bh->b_size = jh2bh(jh_in)->b_size; > > @@ -412,7 +411,11 @@ repeat: > > * copying is moved to the transaction's shadow queue. > > */ > > JBUFFER_TRACE(jh_in, "file as BJ_Shadow"); > > - jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow); > > + spin_lock(&journal->j_list_lock); > > + __jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow); > > + spin_unlock(&journal->j_list_lock); > > + jbd_unlock_bh_state(bh_in); > > + > > JBUFFER_TRACE(new_jh, "file as BJ_IO"); > > jbd2_journal_file_buffer(new_jh, transaction, BJ_IO); > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > Jan Kara <jack@suse.cz> > SuSE CR Labs > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Jul 15, 2009 at 08:13:43PM +0200, Jan Kara wrote: > > Ted, I don't think this got merged... > Ah, I see, jbd2 part got merged by you, I'm not sure about the jbd > part since I didn't see Andrew reply. I guess I'll create a tree for > ext3/jbd changes and merge this patch (and other ext3/jbd fixes I have > here) through it. I did get a note from Andrew saying he had grabbed the patch. It probably hasn't been published in his mmotm tree yet. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu 16-07-09 21:36:12, Theodore Tso wrote: > On Wed, Jul 15, 2009 at 08:13:43PM +0200, Jan Kara wrote: > > > Ted, I don't think this got merged... > > Ah, I see, jbd2 part got merged by you, I'm not sure about the jbd > > part since I didn't see Andrew reply. I guess I'll create a tree for > > ext3/jbd changes and merge this patch (and other ext3/jbd fixes I have > > here) through it. > > I did get a note from Andrew saying he had grabbed the patch. It > probably hasn't been published in his mmotm tree yet. Thanks for info. Yes, I can see the patch in mmotm now. Honza
diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c index 737f724..ff5dcb5 100644 --- a/fs/jbd/journal.c +++ b/fs/jbd/journal.c @@ -287,6 +287,7 @@ int journal_write_metadata_buffer(transaction_t *transaction, struct page *new_page; unsigned int new_offset; struct buffer_head *bh_in = jh2bh(jh_in); + journal_t *journal = transaction->t_journal; /* * The buffer really shouldn't be locked: only the current committing @@ -300,6 +301,11 @@ int journal_write_metadata_buffer(transaction_t *transaction, J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in)); new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL); + /* keep subsequent assertions sane */ + new_bh->b_state = 0; + init_buffer(new_bh, NULL, NULL); + atomic_set(&new_bh->b_count, 1); + new_jh = journal_add_journal_head(new_bh); /* This sleeps */ /* * If a new transaction has already done a buffer copy-out, then @@ -361,14 +367,6 @@ repeat: kunmap_atomic(mapped_data, KM_USER0); } - /* keep subsequent assertions sane */ - new_bh->b_state = 0; - init_buffer(new_bh, NULL, NULL); - atomic_set(&new_bh->b_count, 1); - jbd_unlock_bh_state(bh_in); - - new_jh = journal_add_journal_head(new_bh); /* This sleeps */ - set_bh_page(new_bh, new_page, new_offset); new_jh->b_transaction = NULL; new_bh->b_size = jh2bh(jh_in)->b_size; @@ -385,7 +383,11 @@ repeat: * copying is moved to the transaction's shadow queue. */ JBUFFER_TRACE(jh_in, "file as BJ_Shadow"); - journal_file_buffer(jh_in, transaction, BJ_Shadow); + spin_lock(&journal->j_list_lock); + __journal_file_buffer(jh_in, transaction, BJ_Shadow); + spin_unlock(&journal->j_list_lock); + jbd_unlock_bh_state(bh_in); + JBUFFER_TRACE(new_jh, "file as BJ_IO"); journal_file_buffer(new_jh, transaction, BJ_IO); diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 18bfd5d..4a0b48f 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -297,6 +297,8 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction, unsigned int new_offset; struct buffer_head *bh_in = jh2bh(jh_in); struct jbd2_buffer_trigger_type *triggers; + journal_t *journal = transaction->t_journal; + /* * The buffer really shouldn't be locked: only the current committing @@ -310,6 +312,11 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction, J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in)); new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL); + /* keep subsequent assertions sane */ + new_bh->b_state = 0; + init_buffer(new_bh, NULL, NULL); + atomic_set(&new_bh->b_count, 1); + new_jh = jbd2_journal_add_journal_head(new_bh); /* This sleeps */ /* * If a new transaction has already done a buffer copy-out, then @@ -388,14 +395,6 @@ repeat: kunmap_atomic(mapped_data, KM_USER0); } - /* keep subsequent assertions sane */ - new_bh->b_state = 0; - init_buffer(new_bh, NULL, NULL); - atomic_set(&new_bh->b_count, 1); - jbd_unlock_bh_state(bh_in); - - new_jh = jbd2_journal_add_journal_head(new_bh); /* This sleeps */ - set_bh_page(new_bh, new_page, new_offset); new_jh->b_transaction = NULL; new_bh->b_size = jh2bh(jh_in)->b_size; @@ -412,7 +411,11 @@ repeat: * copying is moved to the transaction's shadow queue. */ JBUFFER_TRACE(jh_in, "file as BJ_Shadow"); - jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow); + spin_lock(&journal->j_list_lock); + __jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow); + spin_unlock(&journal->j_list_lock); + jbd_unlock_bh_state(bh_in); + JBUFFER_TRACE(new_jh, "file as BJ_IO"); jbd2_journal_file_buffer(new_jh, transaction, BJ_IO); -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in