[PATCH v3 1/6] ntfs: report allocation metadata errors to fsnotify

[Baolin Liu <liubaolin12138@163.com>]

From: Baolin Liu <liubaolin@kylinos.cn>

Cluster allocation and free rollbacks can leave volume metadata
inconsistent without notifying filesystem health monitors.

Add a volume-level helper that records the error and reports it through
fsnotify after mount activation. Report each failed rollback where it
is detected and leave event merging to fanotify.

Signed-off-by: Baolin Liu <liubaolin@kylinos.cn>
---
 fs/ntfs/lcnalloc.c | 4 ++--
 fs/ntfs/super.c    | 8 ++++++++
 fs/ntfs/volume.h   | 2 ++
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/fs/ntfs/lcnalloc.c b/fs/ntfs/lcnalloc.c
index 0d6cd08ee2e7..347f9e152588 100644
--- a/fs/ntfs/lcnalloc.c
+++ b/fs/ntfs/lcnalloc.c
@@ -763,7 +763,7 @@ switch_to_data1_zone:		search_zone = 2;
 			ntfs_error(vol->sb,
 				"Failed to rollback (error %i). Leaving inconsistent metadata! Unmount and run chkdsk.",
 				err2);
-			NVolSetErrors(vol);
+			ntfs_report_metadata_error(vol, err2);
 		}
 		/* Free the runlist. */
 		kvfree(rl);
@@ -1044,7 +1044,7 @@ s64 __ntfs_cluster_free(struct ntfs_inode *ni, const s64 start_vcn, s64 count,
 		ntfs_error(vol->sb,
 			"Failed to rollback (error %i).  Leaving inconsistent metadata!  Unmount and run chkdsk.",
 			(int)delta);
-		NVolSetErrors(vol);
+		ntfs_report_metadata_error(vol, delta);
 	} else {
 		ntfs_dec_free_clusters(vol, delta);
 	}
diff --git a/fs/ntfs/super.c b/fs/ntfs/super.c
index 716ba775f1f3..827313df0e28 100644
--- a/fs/ntfs/super.c
+++ b/fs/ntfs/super.c
@@ -14,6 +14,7 @@
 #include <linux/sched/mm.h>
 #include <linux/fs_context.h>
 #include <linux/fs_parser.h>
+#include <linux/fserror.h>
 
 #include "sysctl.h"
 #include "logfile.h"
@@ -394,6 +395,13 @@ const struct option_t on_errors_arr[] = {
 	{ 0,			NULL }
 };
 
+void ntfs_report_metadata_error(struct ntfs_volume *vol, int error)
+{
+	NVolSetErrors(vol);
+	if (vol->sb->s_flags & SB_ACTIVE)
+		fserror_report_metadata(vol->sb, error, GFP_ATOMIC);
+}
+
 void ntfs_handle_error(struct super_block *sb)
 {
 	struct ntfs_volume *vol = NTFS_SB(sb);
diff --git a/fs/ntfs/volume.h b/fs/ntfs/volume.h
index fdb57279de84..5bcd0dd2a19d 100644
--- a/fs/ntfs/volume.h
+++ b/fs/ntfs/volume.h
@@ -254,6 +254,8 @@ DEFINE_NVOL_BIT_OPS(DisableSparse)
 DEFINE_NVOL_BIT_OPS(NativeSymlinkRel)
 DEFINE_NVOL_BIT_OPS(SymlinkNative)
 
+void ntfs_report_metadata_error(struct ntfs_volume *vol, int error);
+
 static inline void ntfs_inc_free_clusters(struct ntfs_volume *vol, s64 nr)
 {
 	if (!NVolFreeClusterKnown(vol))
-- 
2.51.0