gfs2: Don't withdraw under a spin lock

In two places, the gfs2_io_error_bh macro is called while holding the
sd_ail_lock spin lock.  This isn't allowed because gfs2_io_error_bh
withdraws the filesystem, which can sleep because it issues a uevent.
To fix that, add a gfs2_io_error_bh_wd macro that does withdraw the
filesystem and change gfs2_io_error_bh to not withdraw the filesystem.
In those places where the new gfs2_io_error_bh is used, withdraw the
filesystem after releasing sd_ail_lock.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andrew Price <anprice@redhat.com>

1 files changed, 20 insertions, 18 deletions

diff --git a/fs/gfs2/util.c b/fs/gfs2/util.c
index 763d659db91b..59c811de0dc7 100644
--- a/fs/gfs2/util.c
+++ b/fs/gfs2/util.c
@@ -46,14 +46,16 @@ int gfs2_lm_withdraw(struct gfs2_sbd *sdp, const char *fmt, ...)
 	    test_and_set_bit(SDF_SHUTDOWN, &sdp->sd_flags))
 		return 0;
 
-	va_start(args, fmt);
+	if (fmt) {
+		va_start(args, fmt);
 
-	vaf.fmt = fmt;
-	vaf.va = &args;
+		vaf.fmt = fmt;
+		vaf.va = &args;
 
-	fs_err(sdp, "%pV", &vaf);
+		fs_err(sdp, "%pV", &vaf);
 
-	va_end(args);
+		va_end(args);
+	}
 
 	if (sdp->sd_args.ar_errors == GFS2_ERRORS_WITHDRAW) {
 		fs_err(sdp, "about to withdraw this file system\n");
@@ -246,21 +248,21 @@ int gfs2_io_error_i(struct gfs2_sbd *sdp, const char *function, char *file,
 }
 
 /**
- * gfs2_io_error_bh_i - Flag a buffer I/O error and withdraw
- * Returns: -1 if this call withdrew the machine,
- *          0 if it was already withdrawn
+ * gfs2_io_error_bh_i - Flag a buffer I/O error
+ * @withdraw: withdraw the filesystem
  */
 
-int gfs2_io_error_bh_i(struct gfs2_sbd *sdp, struct buffer_head *bh,
-		       const char *function, char *file, unsigned int line)
+void gfs2_io_error_bh_i(struct gfs2_sbd *sdp, struct buffer_head *bh,
+			const char *function, char *file, unsigned int line,
+			bool withdraw)
 {
-	int rv;
-	rv = gfs2_lm_withdraw(sdp,
-			      "fatal: I/O error\n"
-			      "  block = %llu\n"
-			      "  function = %s, file = %s, line = %u\n",
-			      (unsigned long long)bh->b_blocknr,
-			      function, file, line);
-	return rv;
+	fs_err(sdp,
+	       "fatal: I/O error\n"
+	       "  block = %llu\n"
+	       "  function = %s, file = %s, line = %u\n",
+	       (unsigned long long)bh->b_blocknr,
+	       function, file, line);
+	if (withdraw)
+		gfs2_lm_withdraw(sdp, NULL);
 }