[PATCH v7 23/28] fanotify: Report fid info for file related file system errors
From: Gabriel Krisman Bertazi <hidden>
Date: 2021-10-14 21:39:44
Also in:
linux-api, linux-fsdevel
Subsystem:
fanotify, filesystems (vfs and infrastructure), fsnotify: filesystem notification infrastructure, the rest · Maintainers:
Jan Kara, Alexander Viro, Christian Brauner, Linus Torvalds
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. Signed-off-by: Gabriel Krisman Bertazi <redacted> --- 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 | 15 +++++++++++++++ fs/notify/fanotify/fanotify.h | 8 ++++++++ 2 files changed, 23 insertions(+)
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 7032083df62a..8a60c96f5fb2 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c@@ -611,7 +611,9 @@ static struct fanotify_event *fanotify_alloc_error_event( { struct fs_error_report *report = fsnotify_data_error_report(data, data_type); + struct inode *inode = report->inode; struct fanotify_error_event *fee; + int fh_len; if (WARN_ON(!report)) return NULL;
@@ -622,6 +624,19 @@ static struct fanotify_event *fanotify_alloc_error_event( fee->fae.type = FANOTIFY_EVENT_TYPE_FS_ERROR; fee->err_count = 1; + fee->fsid = *fsid; + + fh_len = fanotify_encode_fh_len(inode); + if (WARN_ON(fh_len > MAX_HANDLE_SZ)) { + /* + * Fallback to reporting the error against the super + * block. It should never happen. + */ + inode = NULL; + fh_len = fanotify_encode_fh_len(NULL); + } + + fanotify_encode_fh(&fee->object_fh, inode, fh_len, NULL, 0); *hash ^= fanotify_hash_fsid(fsid);
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index 2b032b79d5b0..b58400926f92 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h@@ -202,6 +202,10 @@ struct fanotify_error_event { u32 err_count; /* Suppressed errors count */ __kernel_fsid_t fsid; /* FSID this error refers to. */ + /* object_fh must be followed by the inline handle buffer. */ + struct fanotify_fh object_fh; + /* Reserve space in object_fh.buf[] - access with fanotify_fh_buf() */ + unsigned char _inline_fh_buf[MAX_HANDLE_SZ]; }; static inline struct fanotify_error_event *
@@ -216,6 +220,8 @@ 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; }
@@ -227,6 +233,8 @@ 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; }
--
2.33.0