ocfs2: Resolve deadlock in ocfs2_xattr_free_block.

In ocfs2_xattr_free_block, we take a cluster lock on xb_alloc_inode while we
have a transaction open. This will deadlock the downconvert thread, so fix
it.

We can clean up how xattr blocks are removed while here - this patch also
moves the mechanism of releasing xattr block (including both value, xattr
tree and xattr block) into this function.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 38e3e5e216bdb460620453bec4996371c218cc9b..b2e25a828e382846c33a9503c633735aaf53d2a4 100644 (file)
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -1427,51 +1427,6 @@ out:
 
 }
 
-static int ocfs2_xattr_free_block(handle_t *handle,
-                                 struct ocfs2_super *osb,
-                                 struct ocfs2_xattr_block *xb)
-{
-       struct inode *xb_alloc_inode;
-       struct buffer_head *xb_alloc_bh = NULL;
-       u64 blk = le64_to_cpu(xb->xb_blkno);
-       u16 bit = le16_to_cpu(xb->xb_suballoc_bit);
-       u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
-       int ret = 0;
-
-       xb_alloc_inode = ocfs2_get_system_file_inode(osb,
-                               EXTENT_ALLOC_SYSTEM_INODE,
-                               le16_to_cpu(xb->xb_suballoc_slot));
-       if (!xb_alloc_inode) {
-               ret = -ENOMEM;
-               mlog_errno(ret);
-               goto out;
-       }
-       mutex_lock(&xb_alloc_inode->i_mutex);
-
-       ret = ocfs2_inode_lock(xb_alloc_inode, &xb_alloc_bh, 1);
-       if (ret < 0) {
-               mlog_errno(ret);
-               goto out_mutex;
-       }
-       ret = ocfs2_extend_trans(handle, OCFS2_SUBALLOC_FREE);
-       if (ret < 0) {
-               mlog_errno(ret);
-               goto out_unlock;
-       }
-       ret = ocfs2_free_suballoc_bits(handle, xb_alloc_inode, xb_alloc_bh,
-                                      bit, bg_blkno, 1);
-       if (ret < 0)
-               mlog_errno(ret);
-out_unlock:
-       ocfs2_inode_unlock(xb_alloc_inode, 1);
-       brelse(xb_alloc_bh);
-out_mutex:
-       mutex_unlock(&xb_alloc_inode->i_mutex);
-       iput(xb_alloc_inode);
-out:
-       return ret;
-}
-
 static int ocfs2_remove_value_outside(struct inode*inode,
                                      struct buffer_head *bh,
                                      struct ocfs2_xattr_header *header)
@@ -1533,6 +1488,84 @@ static int ocfs2_xattr_block_remove(struct inode *inode,
        return ret;
 }
 
+static int ocfs2_xattr_free_block(struct inode *inode,
+                                 u64 block)
+{
+       struct inode *xb_alloc_inode;
+       struct buffer_head *xb_alloc_bh = NULL;
+       struct buffer_head *blk_bh = NULL;
+       struct ocfs2_xattr_block *xb;
+       struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+       handle_t *handle;
+       int ret = 0;
+       u64 blk, bg_blkno;
+       u16 bit;
+
+       ret = ocfs2_read_block(osb, block, &blk_bh,
+                              OCFS2_BH_CACHED, inode);
+       if (ret < 0) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       /*Verify the signature of xattr block*/
+       if (memcmp((void *)blk_bh->b_data, OCFS2_XATTR_BLOCK_SIGNATURE,
+                  strlen(OCFS2_XATTR_BLOCK_SIGNATURE))) {
+               ret = -EFAULT;
+               goto out;
+       }
+
+       ret = ocfs2_xattr_block_remove(inode, blk_bh);
+       if (ret < 0) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
+       blk = le64_to_cpu(xb->xb_blkno);
+       bit = le16_to_cpu(xb->xb_suballoc_bit);
+       bg_blkno = ocfs2_which_suballoc_group(blk, bit);
+
+       xb_alloc_inode = ocfs2_get_system_file_inode(osb,
+                               EXTENT_ALLOC_SYSTEM_INODE,
+                               le16_to_cpu(xb->xb_suballoc_slot));
+       if (!xb_alloc_inode) {
+               ret = -ENOMEM;
+               mlog_errno(ret);
+               goto out;
+       }
+       mutex_lock(&xb_alloc_inode->i_mutex);
+
+       ret = ocfs2_inode_lock(xb_alloc_inode, &xb_alloc_bh, 1);
+       if (ret < 0) {
+               mlog_errno(ret);
+               goto out_mutex;
+       }
+
+       handle = ocfs2_start_trans(osb, OCFS2_SUBALLOC_FREE);
+       if (IS_ERR(handle)) {
+               ret = PTR_ERR(handle);
+               mlog_errno(ret);
+               goto out_unlock;
+       }
+
+       ret = ocfs2_free_suballoc_bits(handle, xb_alloc_inode, xb_alloc_bh,
+                                      bit, bg_blkno, 1);
+       if (ret < 0)
+               mlog_errno(ret);
+
+       ocfs2_commit_trans(osb, handle);
+out_unlock:
+       ocfs2_inode_unlock(xb_alloc_inode, 1);
+       brelse(xb_alloc_bh);
+out_mutex:
+       mutex_unlock(&xb_alloc_inode->i_mutex);
+       iput(xb_alloc_inode);
+out:
+       brelse(blk_bh);
+       return ret;
+}
+
 /*
  * ocfs2_xattr_remove()
  *
@@ -1540,9 +1573,6 @@ static int ocfs2_xattr_block_remove(struct inode *inode,
  */
 int ocfs2_xattr_remove(struct inode *inode, struct buffer_head *di_bh)
 {
-       struct ocfs2_xattr_block *xb;
-       struct buffer_head *blk_bh = NULL;
-       struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
        struct ocfs2_inode_info *oi = OCFS2_I(inode);
        struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
        handle_t *handle;
@@ -1561,22 +1591,10 @@ int ocfs2_xattr_remove(struct inode *inode, struct buffer_head *di_bh)
                        goto out;
                }
        }
-       if (di->i_xattr_loc) {
-               ret = ocfs2_read_block(OCFS2_SB(inode->i_sb),
-                                      le64_to_cpu(di->i_xattr_loc),
-                                      &blk_bh, OCFS2_BH_CACHED, inode);
-               if (ret < 0) {
-                       mlog_errno(ret);
-                       return ret;
-               }
-               /*Verify the signature of xattr block*/
-               if (memcmp((void *)blk_bh->b_data, OCFS2_XATTR_BLOCK_SIGNATURE,
-                          strlen(OCFS2_XATTR_BLOCK_SIGNATURE))) {
-                       ret = -EFAULT;
-                       goto out;
-               }
 
-               ret = ocfs2_xattr_block_remove(inode, blk_bh);
+       if (di->i_xattr_loc) {
+               ret = ocfs2_xattr_free_block(inode,
+                                            le64_to_cpu(di->i_xattr_loc));
                if (ret < 0) {
                        mlog_errno(ret);
                        goto out;
@@ -1597,11 +1615,7 @@ int ocfs2_xattr_remove(struct inode *inode, struct buffer_head *di_bh)
                goto out_commit;
        }
 
-       if (di->i_xattr_loc) {
-               xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
-               ocfs2_xattr_free_block(handle, osb, xb);
-               di->i_xattr_loc = cpu_to_le64(0);
-       }
+       di->i_xattr_loc = 0;
 
        spin_lock(&oi->ip_lock);
        oi->ip_dyn_features &= ~(OCFS2_INLINE_XATTR_FL | OCFS2_HAS_XATTR_FL);
@@ -1614,8 +1628,6 @@ int ocfs2_xattr_remove(struct inode *inode, struct buffer_head *di_bh)
 out_commit:
        ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
 out:
-       brelse(blk_bh);
-
        return ret;
 }