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, 15 insertions, 40 deletions

diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index b75b2e1f0e4..c5c183ac41f 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -382,18 +382,13 @@ static int ocfs2_truncate_file(struct inode *inode,
 
         down_write(&OCFS2_I(inode)->ip_alloc_sem);
 
-        /* This forces other nodes to sync and drop their pages. Do
-         * this even if we have a truncate without allocation change -
-         * ocfs2 cluster sizes can be much greater than page size, so
-         * we have to truncate them anyway.  */
-        status = ocfs2_data_lock(inode, 1);
-        if (status < 0) {
-                up_write(&OCFS2_I(inode)->ip_alloc_sem);
-
-                mlog_errno(status);
-                goto bail;
-        }
-
+        /*
+         * The inode lock forced other nodes to sync and drop their
+         * pages, which (correctly) happens even if we have a truncate
+         * without allocation change - ocfs2 cluster sizes can be much
+         * greater than page size, so we have to truncate them
+         * anyway.
+         */
         unmap_mapping_range(inode->i_mapping, new_i_size + PAGE_SIZE - 1, 0, 1);
         truncate_inode_pages(inode->i_mapping, new_i_size);
 
@@ -403,7 +398,7 @@ static int ocfs2_truncate_file(struct inode *inode,
                 if (status)
                         mlog_errno(status);
 
-                goto bail_unlock_data;
+                goto bail_unlock_sem;
         }
 
         /* alright, we're going to need to do a full blown alloc size
@@ -413,25 +408,23 @@ static int ocfs2_truncate_file(struct inode *inode,
         status = ocfs2_orphan_for_truncate(osb, inode, di_bh, new_i_size);
         if (status < 0) {
                 mlog_errno(status);
-                goto bail_unlock_data;
+                goto bail_unlock_sem;
         }
 
         status = ocfs2_prepare_truncate(osb, inode, di_bh, &tc);
         if (status < 0) {
                 mlog_errno(status);
-                goto bail_unlock_data;
+                goto bail_unlock_sem;
         }
 
         status = ocfs2_commit_truncate(osb, inode, di_bh, tc);
         if (status < 0) {
                 mlog_errno(status);
-                goto bail_unlock_data;
+                goto bail_unlock_sem;
         }
 
         /* TODO: orphan dir cleanup here. */
-bail_unlock_data:
-        ocfs2_data_unlock(inode, 1);
-
+bail_unlock_sem:
         up_write(&OCFS2_I(inode)->ip_alloc_sem);
 
 bail:
@@ -917,7 +910,7 @@ static int ocfs2_extend_file(struct inode *inode,
                              struct buffer_head *di_bh,
                              u64 new_i_size)
 {
-        int ret = 0, data_locked = 0;
+        int ret = 0;
         struct ocfs2_inode_info *oi = OCFS2_I(inode);
 
         BUG_ON(!di_bh);
@@ -943,20 +936,6 @@ static int ocfs2_extend_file(struct inode *inode,
             && ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
                 goto out_update_size;
 
-        /* 
-         * protect the pages that ocfs2_zero_extend is going to be
-         * pulling into the page cache.. we do this before the
-         * metadata extend so that we don't get into the situation
-         * where we've extended the metadata but can't get the data
-         * lock to zero.
-         */
-        ret = ocfs2_data_lock(inode, 1);
-        if (ret < 0) {
-                mlog_errno(ret);
-                goto out;
-        }
-        data_locked = 1;
-
         /*
          * The alloc sem blocks people in read/write from reading our
          * allocation until we're done changing it. We depend on
@@ -980,7 +959,7 @@ static int ocfs2_extend_file(struct inode *inode,
                         up_write(&oi->ip_alloc_sem);
 
                         mlog_errno(ret);
-                        goto out_unlock;
+                        goto out;
                 }
         }
 
@@ -991,7 +970,7 @@ static int ocfs2_extend_file(struct inode *inode,
 
         if (ret < 0) {
                 mlog_errno(ret);
-                goto out_unlock;
+                goto out;
         }
 
 out_update_size:
@@ -999,10 +978,6 @@ out_update_size:
         if (ret < 0)
                 mlog_errno(ret);
 
-out_unlock:
-        if (data_locked)
-                ocfs2_data_unlock(inode, 1);
-
 out:
         return ret;
 }