diff mbox series

[v9,26/31] fanotify: Report fid info for file related file system errors

Message ID 20211025192746.66445-27-krisman@collabora.com (mailing list archive)
State New, archived
Headers show
Series file system-wide error monitoring | expand

Commit Message

Gabriel Krisman Bertazi Oct. 25, 2021, 7:27 p.m. UTC 
Plumb the pieces to add a FID report to error records.  Since all error
event memory must be pre-allocated, we pre-allocate the maximum file
handle size possible, such that it should always fit.

For errors that don't expose a file handle report it with an invalid
FID.

Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>

---
Changes since v8:
  - Drop comment (Amir)
  - Move report dereference till after null check (jan)
  - Move has_object_fh hunk to earlier patch (jan)
Changes since v7:
  - Move WARN_ON to separate patch (Amir)
  - Avoid duplication in the structure definition (Amir)
Changes since v6:
  - pass fsid from handle_events
Changes since v5:
  - Use preallocated MAX_HANDLE_SZ FH buffer
  - Report superblock errors with a zerolength INVALID FID (jan, amir)
---
 fs/notify/fanotify/fanotify.c | 11 +++++++++++
 fs/notify/fanotify/fanotify.h |  6 ++++++
 2 files changed, 17 insertions(+)
diff mbox series

Patch

diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 45df610debbe..465f07e70e6d 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -609,7 +609,9 @@  static struct fanotify_event *fanotify_alloc_error_event(
 {
 	struct fs_error_report *report =
 			fsnotify_data_error_report(data, data_type);
+	struct inode *inode;
 	struct fanotify_error_event *fee;
+	int fh_len;
 
 	if (WARN_ON_ONCE(!report))
 		return NULL;
@@ -622,6 +624,15 @@  static struct fanotify_event *fanotify_alloc_error_event(
 	fee->err_count = 1;
 	fee->fsid = *fsid;
 
+	inode = report->inode;
+	fh_len = fanotify_encode_fh_len(inode);
+
+	/* Bad fh_len. Fallback to using an invalid fh. Should never happen. */
+	if (!fh_len && inode)
+		inode = NULL;
+
+	fanotify_encode_fh(&fee->object_fh, inode, fh_len, NULL, 0);
+
 	*hash ^= fanotify_hash_fsid(fsid);
 
 	return &fee->fae;
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index f51ab6e556e8..edd7587adcc5 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -208,6 +208,8 @@  struct fanotify_error_event {
 	u32 err_count; /* Suppressed errors count */
 
 	__kernel_fsid_t fsid; /* FSID this error refers to. */
+
+	FANOTIFY_INLINE_FH(object_fh, MAX_HANDLE_SZ);
 };
 
 static inline struct fanotify_error_event *
@@ -222,6 +224,8 @@  static inline __kernel_fsid_t *fanotify_event_fsid(struct fanotify_event *event)
 		return &FANOTIFY_FE(event)->fsid;
 	else if (event->type == FANOTIFY_EVENT_TYPE_FID_NAME)
 		return &FANOTIFY_NE(event)->fsid;
+	else if (event->type == FANOTIFY_EVENT_TYPE_FS_ERROR)
+		return &FANOTIFY_EE(event)->fsid;
 	else
 		return NULL;
 }
@@ -233,6 +237,8 @@  static inline struct fanotify_fh *fanotify_event_object_fh(
 		return &FANOTIFY_FE(event)->object_fh;
 	else if (event->type == FANOTIFY_EVENT_TYPE_FID_NAME)
 		return fanotify_info_file_fh(&FANOTIFY_NE(event)->info);
+	else if (event->type == FANOTIFY_EVENT_TYPE_FS_ERROR)
+		return &FANOTIFY_EE(event)->object_fh;
 	else
 		return NULL;
 }