On Wed, Sep 17, 2008 at 12:22:54PM -0700, Andrew Morton wrote: > On Sat, 13 Sep 2008 11:32:49 -0400 > "Theodore Ts'o" <tytso@xxxxxxx> wrote: > > > From: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> > > > > For blocksize < pagesize we need to remove blocks that got allocated in > > block_write_begin() if we fail with ENOSPC for later blocks. > > block_write_begin() internally does this if it allocated page > > locally. This makes sure we don't have blocks outside inode.i_size > > during ENOSPC. > > > > Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> > > Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx> > > Cc: linux-ext4@xxxxxxxxxxxxxxx > > --- > > fs/ext3/inode.c | 7 +++++++ > > 1 files changed, 7 insertions(+), 0 deletions(-) > > > > diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c > > index 507d868..bff22b9 100644 > > --- a/fs/ext3/inode.c > > +++ b/fs/ext3/inode.c > > @@ -1178,6 +1178,13 @@ write_begin_failed: > > ext3_journal_stop(handle); > > unlock_page(page); > > page_cache_release(page); > > + /* > > + * block_write_begin may have instantiated a few blocks > > + * outside i_size. Trim these off again. Don't need > > + * i_size_read because we hold i_mutex. > > + */ > > + if (pos + len > inode->i_size) > > + vmtruncate(inode, inode->i_size); > > } > > if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries)) > > goto retry; > > Well we used to do this trimming in core VFS, but Nick broke it. We > still do it if the fs doesn't implement ->write_begin(). We still do it in block_write_begin if the pages are allocated by block_write_begin. > > Should we do this trimming in pagecache_write_begin() in both cases? pagecache_write_begin is not used in the write_begin call path for ext3/ext4. generic_file_buffered_write generic_perform_write ext3_write_begin block_write_begin -aneesh -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
