[XFS] fix uninitialised variable bug in dquot release

gcc on ARM warns about an using an uninitialised variable
in xfs_qm_dqrele_all_inodes(). This is a real bug, but gcc
on x86_64 is not reporting this warning so it went unnoticed.

Fix the bug by bring the inode radix tree walk code up to
date with xfs_sync_inodes_ag().

SGI-PV: 987246

Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

1 files changed, 24 insertions, 18 deletions

diff --git a/fs/xfs/quota/xfs_qm_syscalls.c b/fs/xfs/quota/xfs_qm_syscalls.c
index 9ff28e6c5b8b..2c57a6eaff36 100644
--- a/fs/xfs/quota/xfs_qm_syscalls.c
+++ b/fs/xfs/quota/xfs_qm_syscalls.c
@@ -1036,9 +1036,6 @@ xfs_qm_dqrele_inodes_ag(
         int             nr_found;
 
         do {
-                boolean_t       inode_refed;
-                struct inode    *inode;
-
                 /*
                  * use a gang lookup to find the next inode in the tree
                  * as the tree is sparse and a gang lookup walks to find
@@ -1053,27 +1050,37 @@ xfs_qm_dqrele_inodes_ag(
                         break;
                 }
 
-                /* update the index for the next lookup */
+                /*
+                 * Update the index for the next lookup. Catch overflows
+                 * into the next AG range which can occur if we have inodes
+                 * in the last block of the AG and we are currently
+                 * pointing to the last inode.
+                 */
                 first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
+                if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino)) {
+                        read_unlock(&pag->pag_ici_lock);
+                        break;
+                }
 
-                /* skip quota inodes and those in reclaim */
-                inode = VFS_I(ip);
-                if (!inode || ip == XFS_QI_UQIP(mp) || ip == XFS_QI_GQIP(mp)) {
+                /* skip quota inodes */
+                if (ip == XFS_QI_UQIP(mp) || ip == XFS_QI_GQIP(mp)) {
                         ASSERT(ip->i_udquot == NULL);
                         ASSERT(ip->i_gdquot == NULL);
                         read_unlock(&pag->pag_ici_lock);
                         continue;
                 }
-                if (xfs_ilock_nowait(ip, XFS_ILOCK_EXCL) == 0) {
-                        inode = igrab(inode);
-                        read_unlock(&pag->pag_ici_lock);
-                        if (!inode)
-                                continue;
-                        inode_refed = B_TRUE;
-                        xfs_ilock(ip, XFS_ILOCK_EXCL);
-                } else {
+
+                /*
+                 * If we can't get a reference on the inode, it must be
+                 * in reclaim. Leave it for the reclaim code to flush.
+                 */
+                if (!igrab(VFS_I(ip))) {
                         read_unlock(&pag->pag_ici_lock);
+                        continue;
                 }
+                read_unlock(&pag->pag_ici_lock);
+
+                xfs_ilock(ip, XFS_ILOCK_EXCL);
                 if ((flags & XFS_UQUOTA_ACCT) && ip->i_udquot) {
                         xfs_qm_dqrele(ip->i_udquot);
                         ip->i_udquot = NULL;
@@ -1083,9 +1090,8 @@ xfs_qm_dqrele_inodes_ag(
                         xfs_qm_dqrele(ip->i_gdquot);
                         ip->i_gdquot = NULL;
                 }
-                xfs_iunlock(ip, XFS_ILOCK_EXCL);
-                if (inode_refed)
-                        IRELE(ip);
+                xfs_iput(ip, XFS_ILOCK_EXCL);
+
         } while (nr_found);
 }