ocfs2: Remove data locks

The meta lock now covers both meta data and data, so this just removes the
now-redundant data lock.

Combining locks saves us a round of lock mastery per inode and one less lock
to ping between nodes during read/write.

We don't lose much - since meta locks were always held before a data lock
(and at the same level) ordered writeout mode (the default) ensured that
flushing for the meta data lock also pushed out data anyways.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

1 files changed, 2 insertions, 42 deletions

diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 56f7790cad46..5fc27cfaee50 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -305,21 +305,12 @@ static int ocfs2_readpage(struct file *file, struct page *page)
                 goto out_alloc;
         }
 
-        ret = ocfs2_data_lock_with_page(inode, 0, page);
-        if (ret != 0) {
-                if (ret == AOP_TRUNCATED_PAGE)
-                        unlock = 0;
-                mlog_errno(ret);
-                goto out_alloc;
-        }
-
         if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
                 ret = ocfs2_readpage_inline(inode, page);
         else
                 ret = block_read_full_page(page, ocfs2_get_block);
         unlock = 0;
 
-        ocfs2_data_unlock(inode, 0);
 out_alloc:
         up_read(&OCFS2_I(inode)->ip_alloc_sem);
 out_meta_unlock:
@@ -638,34 +629,12 @@ static ssize_t ocfs2_direct_IO(int rw,
         if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
                 return 0;
 
-        if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) {
-                /*
-                 * We get PR data locks even for O_DIRECT.  This
-                 * allows concurrent O_DIRECT I/O but doesn't let
-                 * O_DIRECT with extending and buffered zeroing writes
-                 * race.  If they did race then the buffered zeroing
-                 * could be written back after the O_DIRECT I/O.  It's
-                 * one thing to tell people not to mix buffered and
-                 * O_DIRECT writes, but expecting them to understand
-                 * that file extension is also an implicit buffered
-                 * write is too much.  By getting the PR we force
-                 * writeback of the buffered zeroing before
-                 * proceeding.
-                 */
-                ret = ocfs2_data_lock(inode, 0);
-                if (ret < 0) {
-                        mlog_errno(ret);
-                        goto out;
-                }
-                ocfs2_data_unlock(inode, 0);
-        }
-
         ret = blockdev_direct_IO_no_locking(rw, iocb, inode,
                                             inode->i_sb->s_bdev, iov, offset,
                                             nr_segs, 
                                             ocfs2_direct_IO_get_blocks,
                                             ocfs2_dio_end_io);
-out:
+
         mlog_exit(ret);
         return ret;
 }
@@ -1769,25 +1738,17 @@ static int ocfs2_write_begin(struct file *file, struct address_space *mapping,
          */
         down_write(&OCFS2_I(inode)->ip_alloc_sem);
 
-        ret = ocfs2_data_lock(inode, 1);
-        if (ret) {
-                mlog_errno(ret);
-                goto out_fail;
-        }
-
         ret = ocfs2_write_begin_nolock(mapping, pos, len, flags, pagep,
                                        fsdata, di_bh, NULL);
         if (ret) {
                 mlog_errno(ret);
-                goto out_fail_data;
+                goto out_fail;
         }
 
         brelse(di_bh);
 
         return 0;
 
-out_fail_data:
-        ocfs2_data_unlock(inode, 1);
 out_fail:
         up_write(&OCFS2_I(inode)->ip_alloc_sem);
 
@@ -1908,7 +1869,6 @@ static int ocfs2_write_end(struct file *file, struct address_space *mapping,
 
         ret = ocfs2_write_end_nolock(mapping, pos, len, copied, page, fsdata);
 
-        ocfs2_data_unlock(inode, 1);
         up_write(&OCFS2_I(inode)->ip_alloc_sem);
         ocfs2_meta_unlock(inode, 1);