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 <[email protected]>
Acked-by: Jan Kara <[email protected]>
---
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 */
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 <[email protected]>
> Acked-by: Jan Kara <[email protected]>
>
> ---
>
> 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 [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
Jan Kara <[email protected]>
SuSE CR Labs
> 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 <[email protected]>
> > Acked-by: Jan Kara <[email protected]>
> >
> > ---
> >
> > 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 [email protected]
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> --
> Jan Kara <[email protected]>
> SuSE CR Labs
> --
> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
Jan Kara <[email protected]>
SuSE CR Labs
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
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
--
Jan Kara <[email protected]>
SUSE Labs, CR