| Message ID | 1346451711-1931-3-git-send-email-lczerner@redhat.com |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Fri, Aug 31, 2012 at 06:21:38PM -0400, Lukas Czerner wrote: > mm now supports invalidatepage_range address space operation and there > are two file system using jbd2 also implementing punch hole feature > which can benefit from this. We need to implement the same thing for > jbd2 layer in order to allow those file system take benefit of this > functionality. > > With new function jbd2_journal_invalidatepage_range() we can now specify > length to invalidate, rather than assuming invalidate to the end of the > page. > > Signed-off-by: Lukas Czerner <lczerner@redhat.com> > --- > fs/jbd2/journal.c | 1 + > fs/jbd2/transaction.c | 19 +++++++++++++++++-- > include/linux/jbd2.h | 2 ++ > 3 files changed, 20 insertions(+), 2 deletions(-) > > diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c > index e149b99..e4618e9 100644 > --- a/fs/jbd2/journal.c > +++ b/fs/jbd2/journal.c > @@ -86,6 +86,7 @@ EXPORT_SYMBOL(jbd2_journal_force_commit_nested); > EXPORT_SYMBOL(jbd2_journal_wipe); > EXPORT_SYMBOL(jbd2_journal_blocks_per_page); > EXPORT_SYMBOL(jbd2_journal_invalidatepage); > +EXPORT_SYMBOL(jbd2_journal_invalidatepage_range); > EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers); > EXPORT_SYMBOL(jbd2_journal_force_commit); > EXPORT_SYMBOL(jbd2_journal_file_inode); > diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c > index fb1ab953..65c1374 100644 > --- a/fs/jbd2/transaction.c > +++ b/fs/jbd2/transaction.c > @@ -1993,10 +1993,20 @@ zap_buffer_unlocked: > * > */ > void jbd2_journal_invalidatepage(journal_t *journal, > - struct page *page, > - unsigned long offset) > + struct page *page, > + unsigned long offset) > +{ > + jbd2_journal_invalidatepage_range(journal, page, offset, > + PAGE_CACHE_SIZE - offset); > +} > + > +void jbd2_journal_invalidatepage_range(journal_t *journal, > + struct page *page, > + unsigned int offset, > + unsigned int length) > { > struct buffer_head *head, *bh, *next; > + unsigned int stop = offset + length; > unsigned int curr_off = 0; > int may_free = 1; > > @@ -2005,6 +2015,8 @@ void jbd2_journal_invalidatepage(journal_t *journal, > if (!page_has_buffers(page)) > return; > > + BUG_ON(stop > PAGE_CACHE_SIZE || stop < length); This misses e.g. length == (unsigned int)(-1), offset = 1. Could make it obvious with: BUG_ON(offset > PAGE_CACHE_SIZE || length > PAGE_CACHE_SIZE); BUG_ON(stop > PAGE_CACHE_SIZE); Or is that overkill? --b. > + > /* We will potentially be playing with lists other than just the > * data lists (especially for journaled data mode), so be > * cautious in our locking. */ > @@ -2014,6 +2026,9 @@ void jbd2_journal_invalidatepage(journal_t *journal, > unsigned int next_off = curr_off + bh->b_size; > next = bh->b_this_page; > > + if (next_off > stop) > + return; > + > if (offset <= curr_off) { > /* This block is wholly outside the truncation point */ > lock_buffer(bh); > diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h > index 3efc43f..21288fa 100644 > --- a/include/linux/jbd2.h > +++ b/include/linux/jbd2.h > @@ -1101,6 +1101,8 @@ extern int jbd2_journal_forget (handle_t *, struct buffer_head *); > extern void journal_sync_buffer (struct buffer_head *); > extern void jbd2_journal_invalidatepage(journal_t *, > struct page *, unsigned long); > +extern void jbd2_journal_invalidatepage_range(journal_t *, struct page *, > + unsigned int, unsigned int); > extern int jbd2_journal_try_to_free_buffers(journal_t *, struct page *, gfp_t); > extern int jbd2_journal_stop(handle_t *); > extern int jbd2_journal_flush (journal_t *); > -- > 1.7.7.6 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- 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 Tue, 4 Sep 2012, J. Bruce Fields wrote: > Date: Tue, 4 Sep 2012 10:52:13 -0400 > From: J. Bruce Fields <bfields@fieldses.org> > To: Lukas Czerner <lczerner@redhat.com> > Cc: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, tytso@mit.edu, > hughd@google.com, linux-mm@kvack.org > Subject: Re: [PATCH 02/15 v2] jbd2: implement > jbd2_journal_invalidatepage_range > > On Fri, Aug 31, 2012 at 06:21:38PM -0400, Lukas Czerner wrote: > > mm now supports invalidatepage_range address space operation and there > > are two file system using jbd2 also implementing punch hole feature > > which can benefit from this. We need to implement the same thing for > > jbd2 layer in order to allow those file system take benefit of this > > functionality. > > > > With new function jbd2_journal_invalidatepage_range() we can now specify > > length to invalidate, rather than assuming invalidate to the end of the > > page. > > > > Signed-off-by: Lukas Czerner <lczerner@redhat.com> > > --- > > fs/jbd2/journal.c | 1 + > > fs/jbd2/transaction.c | 19 +++++++++++++++++-- > > include/linux/jbd2.h | 2 ++ > > 3 files changed, 20 insertions(+), 2 deletions(-) > > > > diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c > > index e149b99..e4618e9 100644 > > --- a/fs/jbd2/journal.c > > +++ b/fs/jbd2/journal.c > > @@ -86,6 +86,7 @@ EXPORT_SYMBOL(jbd2_journal_force_commit_nested); > > EXPORT_SYMBOL(jbd2_journal_wipe); > > EXPORT_SYMBOL(jbd2_journal_blocks_per_page); > > EXPORT_SYMBOL(jbd2_journal_invalidatepage); > > +EXPORT_SYMBOL(jbd2_journal_invalidatepage_range); > > EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers); > > EXPORT_SYMBOL(jbd2_journal_force_commit); > > EXPORT_SYMBOL(jbd2_journal_file_inode); > > diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c > > index fb1ab953..65c1374 100644 > > --- a/fs/jbd2/transaction.c > > +++ b/fs/jbd2/transaction.c > > @@ -1993,10 +1993,20 @@ zap_buffer_unlocked: > > * > > */ > > void jbd2_journal_invalidatepage(journal_t *journal, > > - struct page *page, > > - unsigned long offset) > > + struct page *page, > > + unsigned long offset) > > +{ > > + jbd2_journal_invalidatepage_range(journal, page, offset, > > + PAGE_CACHE_SIZE - offset); > > +} > > + > > +void jbd2_journal_invalidatepage_range(journal_t *journal, > > + struct page *page, > > + unsigned int offset, > > + unsigned int length) > > { > > struct buffer_head *head, *bh, *next; > > + unsigned int stop = offset + length; > > unsigned int curr_off = 0; > > int may_free = 1; > > > > @@ -2005,6 +2015,8 @@ void jbd2_journal_invalidatepage(journal_t *journal, > > if (!page_has_buffers(page)) > > return; > > > > + BUG_ON(stop > PAGE_CACHE_SIZE || stop < length); > > This misses e.g. length == (unsigned int)(-1), offset = 1. Could make > it obvious with: Hmm.. So if length = -1 (e.g. UINT_MAX) and offset = 1 then: offset + length = 0 so length is bigger than (offset + length) right ? Speaking in numbers: length = 4294967295 offset = 1 stop = length + offset = 0 so (0 < 4294967295) is true and we'll BUG() on this, right ? Am I missing something ? -Lukas > > BUG_ON(offset > PAGE_CACHE_SIZE || length > PAGE_CACHE_SIZE); > BUG_ON(stop > PAGE_CACHE_SIZE); > > Or is that overkill? > > --b. > > > + > > /* We will potentially be playing with lists other than just the > > * data lists (especially for journaled data mode), so be > > * cautious in our locking. */ > > @@ -2014,6 +2026,9 @@ void jbd2_journal_invalidatepage(journal_t *journal, > > unsigned int next_off = curr_off + bh->b_size; > > next = bh->b_this_page; > > > > + if (next_off > stop) > > + return; > > + > > if (offset <= curr_off) { > > /* This block is wholly outside the truncation point */ > > lock_buffer(bh); > > diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h > > index 3efc43f..21288fa 100644 > > --- a/include/linux/jbd2.h > > +++ b/include/linux/jbd2.h > > @@ -1101,6 +1101,8 @@ extern int jbd2_journal_forget (handle_t *, struct buffer_head *); > > extern void journal_sync_buffer (struct buffer_head *); > > extern void jbd2_journal_invalidatepage(journal_t *, > > struct page *, unsigned long); > > +extern void jbd2_journal_invalidatepage_range(journal_t *, struct page *, > > + unsigned int, unsigned int); > > extern int jbd2_journal_try_to_free_buffers(journal_t *, struct page *, gfp_t); > > extern int jbd2_journal_stop(handle_t *); > > extern int jbd2_journal_flush (journal_t *); > > -- > > 1.7.7.6 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- 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 Tue, Sep 04, 2012 at 11:37:13AM -0400, Lukáš Czerner wrote: > On Tue, 4 Sep 2012, J. Bruce Fields wrote: > > > Date: Tue, 4 Sep 2012 10:52:13 -0400 > > From: J. Bruce Fields <bfields@fieldses.org> > > To: Lukas Czerner <lczerner@redhat.com> > > Cc: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, tytso@mit.edu, > > hughd@google.com, linux-mm@kvack.org > > Subject: Re: [PATCH 02/15 v2] jbd2: implement > > jbd2_journal_invalidatepage_range > > > > On Fri, Aug 31, 2012 at 06:21:38PM -0400, Lukas Czerner wrote: > > > mm now supports invalidatepage_range address space operation and there > > > are two file system using jbd2 also implementing punch hole feature > > > which can benefit from this. We need to implement the same thing for > > > jbd2 layer in order to allow those file system take benefit of this > > > functionality. > > > > > > With new function jbd2_journal_invalidatepage_range() we can now specify > > > length to invalidate, rather than assuming invalidate to the end of the > > > page. > > > > > > Signed-off-by: Lukas Czerner <lczerner@redhat.com> > > > --- > > > fs/jbd2/journal.c | 1 + > > > fs/jbd2/transaction.c | 19 +++++++++++++++++-- > > > include/linux/jbd2.h | 2 ++ > > > 3 files changed, 20 insertions(+), 2 deletions(-) > > > > > > diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c > > > index e149b99..e4618e9 100644 > > > --- a/fs/jbd2/journal.c > > > +++ b/fs/jbd2/journal.c > > > @@ -86,6 +86,7 @@ EXPORT_SYMBOL(jbd2_journal_force_commit_nested); > > > EXPORT_SYMBOL(jbd2_journal_wipe); > > > EXPORT_SYMBOL(jbd2_journal_blocks_per_page); > > > EXPORT_SYMBOL(jbd2_journal_invalidatepage); > > > +EXPORT_SYMBOL(jbd2_journal_invalidatepage_range); > > > EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers); > > > EXPORT_SYMBOL(jbd2_journal_force_commit); > > > EXPORT_SYMBOL(jbd2_journal_file_inode); > > > diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c > > > index fb1ab953..65c1374 100644 > > > --- a/fs/jbd2/transaction.c > > > +++ b/fs/jbd2/transaction.c > > > @@ -1993,10 +1993,20 @@ zap_buffer_unlocked: > > > * > > > */ > > > void jbd2_journal_invalidatepage(journal_t *journal, > > > - struct page *page, > > > - unsigned long offset) > > > + struct page *page, > > > + unsigned long offset) > > > +{ > > > + jbd2_journal_invalidatepage_range(journal, page, offset, > > > + PAGE_CACHE_SIZE - offset); > > > +} > > > + > > > +void jbd2_journal_invalidatepage_range(journal_t *journal, > > > + struct page *page, > > > + unsigned int offset, > > > + unsigned int length) > > > { > > > struct buffer_head *head, *bh, *next; > > > + unsigned int stop = offset + length; > > > unsigned int curr_off = 0; > > > int may_free = 1; > > > > > > @@ -2005,6 +2015,8 @@ void jbd2_journal_invalidatepage(journal_t *journal, > > > if (!page_has_buffers(page)) > > > return; > > > > > > + BUG_ON(stop > PAGE_CACHE_SIZE || stop < length); > > > > This misses e.g. length == (unsigned int)(-1), offset = 1. Could make > > it obvious with: > > Hmm.. So if length = -1 (e.g. UINT_MAX) and offset = 1 then: > > offset + length = 0 > > so > > length is bigger than (offset + length) right ? Speaking in numbers: > > length = 4294967295 > offset = 1 > stop = length + offset = 0 > > so (0 < 4294967295) is true and we'll BUG() on this, right ? > > Am I missing something ? Gah, no, I just wasn't thinking straight: the only way offset or length could individually be greater than PAGE_CACHE_SIZE while their sum is less would be if their sum overflows, in which case the second condition (stop < length) would trigger. So the two conditions are enough. --b. -- 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
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index e149b99..e4618e9 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -86,6 +86,7 @@ EXPORT_SYMBOL(jbd2_journal_force_commit_nested); EXPORT_SYMBOL(jbd2_journal_wipe); EXPORT_SYMBOL(jbd2_journal_blocks_per_page); EXPORT_SYMBOL(jbd2_journal_invalidatepage); +EXPORT_SYMBOL(jbd2_journal_invalidatepage_range); EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers); EXPORT_SYMBOL(jbd2_journal_force_commit); EXPORT_SYMBOL(jbd2_journal_file_inode); diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index fb1ab953..65c1374 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -1993,10 +1993,20 @@ zap_buffer_unlocked: * */ void jbd2_journal_invalidatepage(journal_t *journal, - struct page *page, - unsigned long offset) + struct page *page, + unsigned long offset) +{ + jbd2_journal_invalidatepage_range(journal, page, offset, + PAGE_CACHE_SIZE - offset); +} + +void jbd2_journal_invalidatepage_range(journal_t *journal, + struct page *page, + unsigned int offset, + unsigned int length) { struct buffer_head *head, *bh, *next; + unsigned int stop = offset + length; unsigned int curr_off = 0; int may_free = 1; @@ -2005,6 +2015,8 @@ void jbd2_journal_invalidatepage(journal_t *journal, if (!page_has_buffers(page)) return; + BUG_ON(stop > PAGE_CACHE_SIZE || stop < length); + /* We will potentially be playing with lists other than just the * data lists (especially for journaled data mode), so be * cautious in our locking. */ @@ -2014,6 +2026,9 @@ void jbd2_journal_invalidatepage(journal_t *journal, unsigned int next_off = curr_off + bh->b_size; next = bh->b_this_page; + if (next_off > stop) + return; + if (offset <= curr_off) { /* This block is wholly outside the truncation point */ lock_buffer(bh); diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index 3efc43f..21288fa 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -1101,6 +1101,8 @@ extern int jbd2_journal_forget (handle_t *, struct buffer_head *); extern void journal_sync_buffer (struct buffer_head *); extern void jbd2_journal_invalidatepage(journal_t *, struct page *, unsigned long); +extern void jbd2_journal_invalidatepage_range(journal_t *, struct page *, + unsigned int, unsigned int); extern int jbd2_journal_try_to_free_buffers(journal_t *, struct page *, gfp_t); extern int jbd2_journal_stop(handle_t *); extern int jbd2_journal_flush (journal_t *);
mm now supports invalidatepage_range address space operation and there are two file system using jbd2 also implementing punch hole feature which can benefit from this. We need to implement the same thing for jbd2 layer in order to allow those file system take benefit of this functionality. With new function jbd2_journal_invalidatepage_range() we can now specify length to invalidate, rather than assuming invalidate to the end of the page. Signed-off-by: Lukas Czerner <lczerner@redhat.com> --- fs/jbd2/journal.c | 1 + fs/jbd2/transaction.c | 19 +++++++++++++++++-- include/linux/jbd2.h | 2 ++ 3 files changed, 20 insertions(+), 2 deletions(-)