Merge tag 'health-monitoring-7.0_2026-01-20' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into xfs-7.0-merge

xfs: autonomous self healing of filesystems [v7]

This patchset builds new functionality to deliver live information about
filesystem health events to userspace.  This is done by creating an
anonymous file that can be read() for events by userspace programs.
Events are captured by hooking various parts of XFS and iomap so that
metadata health failures, file I/O errors, and major changes in
filesystem state (unmounts, shutdowns, etc.) can be observed by
programs.

When an event occurs, the hook functions queue an event object to each
event anonfd for later processing.  Programs must have CAP_SYS_ADMIN
to open the anonfd and there's a maximum event lag to prevent resource
overconsumption.  The events themselves can be read() from the anonfd
as C structs for the xfs_healer daemon.

In userspace, we create a new daemon program that will read the event
objects and initiate repairs automatically.  This daemon is managed
entirely by systemd and will not block unmounting of the filesystem
unless repairs are ongoing.  They are auto-started by a starter
service that uses fanotify.

This patchset depends on the new fserror code that Christian Brauner
has tentatively accepted for Linux 7.0:
https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git/log/?h=vfs-7.0.fserror

v7: more cleanups of the media verification ioctl, improve comments, and
    reuse the bio
v6: fix pi-breaking bugs, make verify failures trigger health reports
    and filter bio status flags better
v5: add verify-media ioctl, collapse small helper funcs with only
    one caller
v4: drop multiple client support so we can make direct calls into
    healthmon instead of chasing pointers and doing indirect calls
v3: drag out of rfc status

With a bit of luck, this should all go splendidly.

Conflicts:
	This merge required an update on files:
		- fs/xfs/xfs_healthmon.c
		- fs/xfs/xfs_verify_media.c
	Such change was required because a parallel developement changed
	XFS header file xfs.h naming to xfs_platform.h, so the merge
	required to update those includes in both files above

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

4 files changed, 84 insertions, 3 deletions

diff --git a/include/linux/fs/super_types.h b/include/linux/fs/super_types.h
index 6bd3009e09b3..97a8552d8f2b 100644
--- a/include/linux/fs/super_types.h
+++ b/include/linux/fs/super_types.h
@@ -35,6 +35,7 @@ struct user_namespace;
 struct workqueue_struct;
 struct writeback_control;
 struct xattr_handler;
+struct fserror_event;
 
 extern struct super_block *blockdev_superblock;
 
@@ -124,6 +125,9 @@ struct super_operations {
 	 */
 	int (*remove_bdev)(struct super_block *sb, struct block_device *bdev);
 	void (*shutdown)(struct super_block *sb);
+
+	/* Report a filesystem error */
+	void (*report_error)(const struct fserror_event *event);
 };
 
 struct super_block {
@@ -268,6 +272,9 @@ struct super_block {
 	spinlock_t				s_inode_wblist_lock;
 	struct list_head			s_inodes_wb;	/* writeback inodes */
 	long					s_min_writeback_pages;
+
+	/* number of fserrors that are being sent to fsnotify/filesystems */
+	refcount_t				s_pending_errors;
 } __randomize_layout;
 
 /*
diff --git a/include/linux/fserror.h b/include/linux/fserror.h
new file mode 100644
index 000000000000..5e1ad78c346e
--- /dev/null
+++ b/include/linux/fserror.h
@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2025 Oracle.  All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#ifndef _LINUX_FSERROR_H__
+#define _LINUX_FSERROR_H__
+
+void fserror_mount(struct super_block *sb);
+void fserror_unmount(struct super_block *sb);
+
+enum fserror_type {
+	/* pagecache I/O failed */
+	FSERR_BUFFERED_READ,
+	FSERR_BUFFERED_WRITE,
+
+	/* direct I/O failed */
+	FSERR_DIRECTIO_READ,
+	FSERR_DIRECTIO_WRITE,
+
+	/* out of band media error reported */
+	FSERR_DATA_LOST,
+
+	/* filesystem metadata */
+	FSERR_METADATA,
+};
+
+struct fserror_event {
+	struct work_struct work;
+	struct super_block *sb;
+	struct inode *inode;
+	loff_t pos;
+	u64 len;
+	enum fserror_type type;
+
+	/* negative error number */
+	int error;
+};
+
+void fserror_report(struct super_block *sb, struct inode *inode,
+		    enum fserror_type type, loff_t pos, u64 len, int error,
+		    gfp_t gfp);
+
+static inline void fserror_report_io(struct inode *inode,
+				     enum fserror_type type, loff_t pos,
+				     u64 len, int error, gfp_t gfp)
+{
+	fserror_report(inode->i_sb, inode, type, pos, len, error, gfp);
+}
+
+static inline void fserror_report_data_lost(struct inode *inode, loff_t pos,
+					    u64 len, gfp_t gfp)
+{
+	fserror_report(inode->i_sb, inode, FSERR_DATA_LOST, pos, len, -EIO,
+		       gfp);
+}
+
+static inline void fserror_report_file_metadata(struct inode *inode, int error,
+						gfp_t gfp)
+{
+	fserror_report(inode->i_sb, inode, FSERR_METADATA, 0, 0, error, gfp);
+}
+
+static inline void fserror_report_metadata(struct super_block *sb, int error,
+					   gfp_t gfp)
+{
+	fserror_report(sb, NULL, FSERR_METADATA, 0, 0, error, gfp);
+}
+
+static inline void fserror_report_shutdown(struct super_block *sb, gfp_t gfp)
+{
+	fserror_report(sb, NULL, FSERR_METADATA, 0, 0, -ESHUTDOWN, gfp);
+}
+
+#endif /* _LINUX_FSERROR_H__ */
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index f5eaf76198f3..a53a00d36228 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -1815,7 +1815,4 @@ static inline int jbd2_handle_buffer_credits(handle_t *handle)
 
 #endif	/* __KERNEL__ */
 
-#define EFSBADCRC	EBADMSG		/* Bad CRC detected */
-#define EFSCORRUPTED	EUCLEAN		/* Filesystem is corrupted */
-
 #endif	/* _LINUX_JBD2_H */
diff --git a/include/uapi/asm-generic/errno.h b/include/uapi/asm-generic/errno.h
index cf9c51ac49f9..92e7ae493ee3 100644
--- a/include/uapi/asm-generic/errno.h
+++ b/include/uapi/asm-generic/errno.h
@@ -55,6 +55,7 @@
 #define	EMULTIHOP	72	/* Multihop attempted */
 #define	EDOTDOT		73	/* RFS specific error */
 #define	EBADMSG		74	/* Not a data message */
+#define	EFSBADCRC	EBADMSG	/* Bad CRC detected */
 #define	EOVERFLOW	75	/* Value too large for defined data type */
 #define	ENOTUNIQ	76	/* Name not unique on network */
 #define	EBADFD		77	/* File descriptor in bad state */
@@ -98,6 +99,7 @@
 #define	EINPROGRESS	115	/* Operation now in progress */
 #define	ESTALE		116	/* Stale file handle */
 #define	EUCLEAN		117	/* Structure needs cleaning */
+#define	EFSCORRUPTED	EUCLEAN	/* Filesystem is corrupted */
 #define	ENOTNAM		118	/* Not a XENIX named type file */
 #define	ENAVAIL		119	/* No XENIX semaphores available */
 #define	EISNAM		120	/* Is a named type file */