Merge branch 'for-linus' of git://oss.sgi.com:8090/xfs/xfs-2.6

* 'for-linus' of git://oss.sgi.com:8090/xfs/xfs-2.6:
  [XFS] Fix memory corruption with small buffer reads
  [XFS] Fix inode list allocation size in writeback.
  [XFS] Don't allow memory reclaim to wait on the filesystem in inode
  [XFS] Fix fsync() b0rkage.
  [XFS] Include linux/random.h in all builds, not just debug builds.

1 files changed, 42 insertions, 70 deletions

diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 70702a60b4bb..e475e3717eb3 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -856,18 +856,14 @@ xfs_readlink(
 /*
  * xfs_fsync
  *
- * This is called to sync the inode and its data out to disk.
- * We need to hold the I/O lock while flushing the data, and
- * the inode lock while flushing the inode.  The inode lock CANNOT
- * be held while flushing the data, so acquire after we're done
- * with that.
+ * This is called to sync the inode and its data out to disk.  We need to hold
+ * the I/O lock while flushing the data, and the inode lock while flushing the
+ * inode.  The inode lock CANNOT be held while flushing the data, so acquire
+ * after we're done with that.
  */
 int
 xfs_fsync(
-        xfs_inode_t     *ip,
-        int             flag,
-        xfs_off_t       start,
-        xfs_off_t       stop)
+        xfs_inode_t     *ip)
 {
         xfs_trans_t     *tp;
         int             error;
@@ -875,103 +871,79 @@ xfs_fsync(
 
         xfs_itrace_entry(ip);
 
-        ASSERT(start >= 0 && stop >= -1);
-
         if (XFS_FORCED_SHUTDOWN(ip->i_mount))
                 return XFS_ERROR(EIO);
 
-        if (flag & FSYNC_DATA)
-                filemap_fdatawait(vn_to_inode(XFS_ITOV(ip))->i_mapping);
+        /* capture size updates in I/O completion before writing the inode. */
+        error = filemap_fdatawait(vn_to_inode(XFS_ITOV(ip))->i_mapping);
+        if (error)
+                return XFS_ERROR(error);
 
         /*
-         * We always need to make sure that the required inode state
-         * is safe on disk.  The vnode might be clean but because
-         * of committed transactions that haven't hit the disk yet.
-         * Likewise, there could be unflushed non-transactional
-         * changes to the inode core that have to go to disk.
+         * We always need to make sure that the required inode state is safe on
+         * disk.  The vnode might be clean but we still might need to force the
+         * log because of committed transactions that haven't hit the disk yet.
+         * Likewise, there could be unflushed non-transactional changes to the
+         * inode core that have to go to disk and this requires us to issue
+         * a synchronous transaction to capture these changes correctly.
          *
-         * The following code depends on one assumption:  that
-         * any transaction that changes an inode logs the core
-         * because it has to change some field in the inode core
-         * (typically nextents or nblocks).  That assumption
-         * implies that any transactions against an inode will
-         * catch any non-transactional updates.  If inode-altering
-         * transactions exist that violate this assumption, the
-         * code breaks.  Right now, it figures that if the involved
-         * update_* field is clear and the inode is unpinned, the
-         * inode is clean.  Either it's been flushed or it's been
-         * committed and the commit has hit the disk unpinning the inode.
-         * (Note that xfs_inode_item_format() called at commit clears
-         * the update_* fields.)
+         * This code relies on the assumption that if the update_* fields
+         * of the inode are clear and the inode is unpinned then it is clean
+         * and no action is required.
          */
         xfs_ilock(ip, XFS_ILOCK_SHARED);
 
-        /* If we are flushing data then we care about update_size
-         * being set, otherwise we care about update_core
-         */
-        if ((flag & FSYNC_DATA) ?
-                        (ip->i_update_size == 0) :
-                        (ip->i_update_core == 0)) {
+        if (!(ip->i_update_size || ip->i_update_core)) {
                 /*
-                 * Timestamps/size haven't changed since last inode
-                 * flush or inode transaction commit.  That means
-                 * either nothing got written or a transaction
-                 * committed which caught the updates.  If the
-                 * latter happened and the transaction hasn't
-                 * hit the disk yet, the inode will be still
-                 * be pinned.  If it is, force the log.
+                 * Timestamps/size haven't changed since last inode flush or
+                 * inode transaction commit.  That means either nothing got
+                 * written or a transaction committed which caught the updates.
+                 * If the latter happened and the transaction hasn't hit the
+                 * disk yet, the inode will be still be pinned.  If it is,
+                 * force the log.
                  */
 
                 xfs_iunlock(ip, XFS_ILOCK_SHARED);
 
                 if (xfs_ipincount(ip)) {
-                        _xfs_log_force(ip->i_mount, (xfs_lsn_t)0,
-                                      XFS_LOG_FORCE |
-                                      ((flag & FSYNC_WAIT)
-                                       ? XFS_LOG_SYNC : 0),
+                        error = _xfs_log_force(ip->i_mount, (xfs_lsn_t)0,
+                                      XFS_LOG_FORCE | XFS_LOG_SYNC,
                                       &log_flushed);
                 } else {
                         /*
-                         * If the inode is not pinned and nothing
-                         * has changed we don't need to flush the
-                         * cache.
+                         * If the inode is not pinned and nothing has changed
+                         * we don't need to flush the cache.
                          */
                         changed = 0;
                 }
-                error = 0;
         } else  {
                 /*
-                 * Kick off a transaction to log the inode
-                 * core to get the updates.  Make it
-                 * sync if FSYNC_WAIT is passed in (which
-                 * is done by everybody but specfs).  The
-                 * sync transaction will also force the log.
+                 * Kick off a transaction to log the inode core to get the
+                 * updates.  The sync transaction will also force the log.
                  */
                 xfs_iunlock(ip, XFS_ILOCK_SHARED);
                 tp = xfs_trans_alloc(ip->i_mount, XFS_TRANS_FSYNC_TS);
-                if ((error = xfs_trans_reserve(tp, 0,
-                                XFS_FSYNC_TS_LOG_RES(ip->i_mount),
-                                0, 0, 0)))  {
+                error = xfs_trans_reserve(tp, 0,
+                                XFS_FSYNC_TS_LOG_RES(ip->i_mount), 0, 0, 0);
+                if (error) {
                         xfs_trans_cancel(tp, 0);
                         return error;
                 }
                 xfs_ilock(ip, XFS_ILOCK_EXCL);
 
                 /*
-                 * Note - it's possible that we might have pushed
-                 * ourselves out of the way during trans_reserve
-                 * which would flush the inode.  But there's no
-                 * guarantee that the inode buffer has actually
-                 * gone out yet (it's delwri).  Plus the buffer
-                 * could be pinned anyway if it's part of an
-                 * inode in another recent transaction.  So we
-                 * play it safe and fire off the transaction anyway.
+                 * Note - it's possible that we might have pushed ourselves out
+                 * of the way during trans_reserve which would flush the inode.
+                 * But there's no guarantee that the inode buffer has actually
+                 * gone out yet (it's delwri).  Plus the buffer could be pinned
+                 * anyway if it's part of an inode in another recent
+                 * transaction.  So we play it safe and fire off the
+                 * transaction anyway.
                  */
                 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
                 xfs_trans_ihold(tp, ip);
                 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
-                if (flag & FSYNC_WAIT)
-                        xfs_trans_set_sync(tp);
+                xfs_trans_set_sync(tp);
                 error = _xfs_trans_commit(tp, 0, &log_flushed);
 
                 xfs_iunlock(ip, XFS_ILOCK_EXCL);