[XFS] Sanitise xfs_log_force error checking.

xfs_log_force() is declared to return an error, but we almost never check
it. We don't need to check it in most cases; if there's a log I/O error
then we'll be shutting down the filesystem anyway and that means we'll
catch the error somewhere else.

However, on certain calls we should be returning an error - sync
transactions, fsync, sync writes, etc. so this isn't a pure black and
white distinction. Hence make xfs_log_force() a void function that issues
a warning to the syslog on error, and call _xfs_log_force() in all the
places where we actually care about the error status returned.

SGI-PV: 980084
SGI-Modid: xfs-linux-melb:xfs-kern:30832a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Niv Sardi <xaiki@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

3 files changed, 30 insertions, 8 deletions

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index bece882f99ec..e29ea0a6d767 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -382,7 +382,27 @@ _xfs_log_force(
                 return xlog_state_sync_all(log, flags, log_flushed);
         else
                 return xlog_state_sync(log, lsn, flags, log_flushed);
-}       /* xfs_log_force */
+}       /* _xfs_log_force */
+
+/*
+ * Wrapper for _xfs_log_force(), to be used when caller doesn't care
+ * about errors or whether the log was flushed or not. This is the normal
+ * interface to use when trying to unpin items or move the log forward.
+ */
+void
+xfs_log_force(
+        xfs_mount_t     *mp,
+        xfs_lsn_t       lsn,
+        uint            flags)
+{
+        int     error;
+        error = _xfs_log_force(mp, lsn, flags, NULL);
+        if (error) {
+                xfs_fs_cmn_err(CE_WARN, mp, "xfs_log_force: "
+                        "error %d returned.", error);
+        }
+}
+
 
 /*
  * Attaches a new iclog I/O completion callback routine during
@@ -634,7 +654,8 @@ xfs_log_unmount_write(xfs_mount_t *mp)
         if (mp->m_flags & XFS_MOUNT_RDONLY)
                 return 0;
 
-        xfs_log_force(mp, 0, XFS_LOG_FORCE|XFS_LOG_SYNC);
+        error = _xfs_log_force(mp, 0, XFS_LOG_FORCE|XFS_LOG_SYNC, NULL);
+        ASSERT(error || !(XLOG_FORCED_SHUTDOWN(log)));
 
 #ifdef DEBUG
         first_iclog = iclog = log->l_iclog;
diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h
index 4cdac048df5e..d1d678ecb63e 100644
--- a/fs/xfs/xfs_log.h
+++ b/fs/xfs/xfs_log.h
@@ -142,8 +142,9 @@ int	  _xfs_log_force(struct xfs_mount *mp,
                          xfs_lsn_t      lsn,
                          uint           flags,
                          int            *log_forced);
-#define xfs_log_force(mp, lsn, flags) \
-        _xfs_log_force(mp, lsn, flags, NULL);
+void      xfs_log_force(struct xfs_mount        *mp,
+                        xfs_lsn_t               lsn,
+                        uint                    flags);
 int       xfs_log_mount(struct xfs_mount        *mp,
                         struct xfs_buftarg      *log_target,
                         xfs_daddr_t             start_block,
diff --git a/fs/xfs/xfs_rw.c b/fs/xfs/xfs_rw.c
index cd3ece6cc918..b0f31c09a76d 100644
--- a/fs/xfs/xfs_rw.c
+++ b/fs/xfs/xfs_rw.c
@@ -126,11 +126,11 @@ xfs_write_sync_logforce(
                  * when we return.
                  */
                 if (iip && iip->ili_last_lsn) {
-                        xfs_log_force(mp, iip->ili_last_lsn,
-                                        XFS_LOG_FORCE | XFS_LOG_SYNC);
+                        error = _xfs_log_force(mp, iip->ili_last_lsn,
+                                        XFS_LOG_FORCE | XFS_LOG_SYNC, NULL);
                 } else if (xfs_ipincount(ip) > 0) {
-                        xfs_log_force(mp, (xfs_lsn_t)0,
-                                        XFS_LOG_FORCE | XFS_LOG_SYNC);
+                        error = _xfs_log_force(mp, (xfs_lsn_t)0,
+                                        XFS_LOG_FORCE | XFS_LOG_SYNC, NULL);
                 }
 
         } else {