On Fri, May 01, 2009 at 07:47:34AM +0200, Ingo Molnar wrote: > > * Frederic Weisbecker <fweisbec@xxxxxxxxx> wrote: > > > reiserfs_read_bitmap_block() uses sb_bread() to read the bitmap block. This > > helper might sleep. > > > > Then, when the bkl was used, it was released at this point. We can then > > relax the write lock too here. > > > > [ Impact: release the reiserfs write lock when it is not needed ] > > > > Cc: Jeff Mahoney <jeffm@xxxxxxxx> > > Cc: Chris Mason <chris.mason@xxxxxxxxxx> > > Cc: Alexander Beregalov <a.beregalov@xxxxxxxxx> > > Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx> > > --- > > fs/reiserfs/bitmap.c | 2 ++ > > 1 files changed, 2 insertions(+), 0 deletions(-) > > > > diff --git a/fs/reiserfs/bitmap.c b/fs/reiserfs/bitmap.c > > index 1470334..6854957 100644 > > --- a/fs/reiserfs/bitmap.c > > +++ b/fs/reiserfs/bitmap.c > > @@ -1249,7 +1249,9 @@ struct buffer_head *reiserfs_read_bitmap_block(struct super_block *sb, > > else if (bitmap == 0) > > block = (REISERFS_DISK_OFFSET_IN_BYTES >> sb->s_blocksize_bits) + 1; > > > > + reiserfs_write_unlock(sb); > > bh = sb_bread(sb, block); > > + reiserfs_write_lock(sb); > > if (bh == NULL) > > reiserfs_warning(sb, "sh-2029: %s: bitmap block (#%u) " > > "reading failed", __func__, block); > > Note, there's a side-effect here: the access to sb->b_blocksize is > moved outside of the lock. Previously it was accessed via the BKL. > On a mounted filesystem sb->b_blocksize is not supposed to change, > so it's probably not an issue - but wanted to mention it. > > Ingo Indeed. Well I guess it can't be dynamically changed. This is something that can be chosen with mkfs on filesystem creation but I guess it can't be changed, at least not while the filesystem is mounted. I hope... Frederic. -- To unsubscribe from this list: send the line "unsubscribe reiserfs-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
