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;