Merge tag 'for-linus-v3.6-rc4' of git://oss.sgi.com/xfs/xfs

Pull xfs bugfixes from Ben Myers:
 - fix uninitialised variable in xfs_rtbuf_get()
 - unlock the AGI buffer when looping in xfs_dialloc
 - check for possible overflow in xfs_ioc_trim

* tag 'for-linus-v3.6-rc4' of git://oss.sgi.com/xfs/xfs:
  xfs: check for possible overflow in xfs_ioc_trim
  xfs: unlock the AGI buffer when looping in xfs_dialloc
  xfs: fix uninitialised variable in xfs_rtbuf_get()

3 files changed, 14 insertions, 11 deletions

diff --git a/fs/xfs/xfs_discard.c b/fs/xfs/xfs_discard.c
index f9c3fe304a17..69cf4fcde03e 100644
--- a/fs/xfs/xfs_discard.c
+++ b/fs/xfs/xfs_discard.c
@@ -179,12 +179,14 @@ xfs_ioc_trim(
 	 * used by the fstrim application.  In the end it really doesn't
 	 * matter as trimming blocks is an advisory interface.
 	 */
+	if (range.start >= XFS_FSB_TO_B(mp, mp->m_sb.sb_dblocks) ||
+	    range.minlen > XFS_FSB_TO_B(mp, XFS_ALLOC_AG_MAX_USABLE(mp)))
+		return -XFS_ERROR(EINVAL);
+
 	start = BTOBB(range.start);
 	end = start + BTOBBT(range.len) - 1;
 	minlen = BTOBB(max_t(u64, granularity, range.minlen));
 
-	if (XFS_BB_TO_FSB(mp, start) >= mp->m_sb.sb_dblocks)
-		return -XFS_ERROR(EINVAL);
 	if (end > XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks) - 1)
 		end = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks)- 1;
 
diff --git a/fs/xfs/xfs_ialloc.c b/fs/xfs/xfs_ialloc.c
index 21e37b55f7e5..5aceb3f8ecd6 100644
--- a/fs/xfs/xfs_ialloc.c
+++ b/fs/xfs/xfs_ialloc.c
@@ -962,23 +962,22 @@ xfs_dialloc(
 		if (!pag->pagi_freecount && !okalloc)
 			goto nextag;
 
+		/*
+		 * Then read in the AGI buffer and recheck with the AGI buffer
+		 * lock held.
+		 */
 		error = xfs_ialloc_read_agi(mp, tp, agno, &agbp);
 		if (error)
 			goto out_error;
 
-		/*
-		 * Once the AGI has been read in we have to recheck
-		 * pagi_freecount with the AGI buffer lock held.
-		 */
 		if (pag->pagi_freecount) {
 			xfs_perag_put(pag);
 			goto out_alloc;
 		}
 
-		if (!okalloc) {
-			xfs_trans_brelse(tp, agbp);
-			goto nextag;
-		}
+		if (!okalloc)
+			goto nextag_relse_buffer;
+
 
 		error = xfs_ialloc_ag_alloc(tp, agbp, &ialloced);
 		if (error) {
@@ -1007,6 +1006,8 @@ xfs_dialloc(
 			return 0;
 		}
 
+nextag_relse_buffer:
+		xfs_trans_brelse(tp, agbp);
 nextag:
 		xfs_perag_put(pag);
 		if (++agno == mp->m_sb.sb_agcount)
diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index 92d4331cd4f1..ca28a4ba4b54 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -857,7 +857,7 @@ xfs_rtbuf_get(
 	xfs_buf_t	*bp;		/* block buffer, result */
 	xfs_inode_t	*ip;		/* bitmap or summary inode */
 	xfs_bmbt_irec_t	map;
-	int		nmap;
+	int		nmap = 1;
 	int		error;		/* error value */
 
 	ip = issum ? mp->m_rsumip : mp->m_rbmip;