This is a note to let you know that I've just added the patch titled
fanotify: Emit generic error info for error event
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
fanotify-emit-generic-error-info-for-error-event.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 5d65f1624acb21ec2b2be51a6607ef92067c4e31
Author: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
Date: Mon Oct 25 16:27:42 2021 -0300
fanotify: Emit generic error info for error event
[ Upstream commit 130a3c742107acff985541c28360c8b40203559c ]
The error info is a record sent to users on FAN_FS_ERROR events
documenting the type of error. It also carries an error count,
documenting how many errors were observed since the last reporting.
Link: https://lore.kernel.org/r/20211025192746.66445-28-krisman@xxxxxxxxxxxxx
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 465f07e70e6dc..af61425e6e3bf 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -621,6 +621,7 @@ static struct fanotify_event *fanotify_alloc_error_event(
return NULL;
fee->fae.type = FANOTIFY_EVENT_TYPE_FS_ERROR;
+ fee->error = report->error;
fee->err_count = 1;
fee->fsid = *fsid;
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index edd7587adcc59..d25f500bf7e79 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -205,6 +205,7 @@ FANOTIFY_NE(struct fanotify_event *event)
struct fanotify_error_event {
struct fanotify_event fae;
+ s32 error; /* Error reported by the Filesystem. */
u32 err_count; /* Suppressed errors count */
__kernel_fsid_t fsid; /* FSID this error refers to. */
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index fa3dac9c59f69..133d9b5ffdb10 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -115,6 +115,8 @@ struct kmem_cache *fanotify_perm_event_cachep __read_mostly;
(sizeof(struct fanotify_event_info_fid) + sizeof(struct file_handle))
#define FANOTIFY_PIDFD_INFO_HDR_LEN \
sizeof(struct fanotify_event_info_pidfd)
+#define FANOTIFY_ERROR_INFO_LEN \
+ (sizeof(struct fanotify_event_info_error))
static int fanotify_fid_info_len(int fh_len, int name_len)
{
@@ -139,6 +141,9 @@ static size_t fanotify_event_len(unsigned int info_mode,
if (!info_mode)
return event_len;
+ if (fanotify_is_error_event(event->mask))
+ event_len += FANOTIFY_ERROR_INFO_LEN;
+
info = fanotify_event_info(event);
if (fanotify_event_has_dir_fh(event)) {
@@ -324,6 +329,28 @@ static int process_access_response(struct fsnotify_group *group,
return -ENOENT;
}
+static size_t copy_error_info_to_user(struct fanotify_event *event,
+ char __user *buf, int count)
+{
+ struct fanotify_event_info_error info;
+ struct fanotify_error_event *fee = FANOTIFY_EE(event);
+
+ info.hdr.info_type = FAN_EVENT_INFO_TYPE_ERROR;
+ info.hdr.pad = 0;
+ info.hdr.len = FANOTIFY_ERROR_INFO_LEN;
+
+ if (WARN_ON(count < info.hdr.len))
+ return -EFAULT;
+
+ info.error = fee->error;
+ info.error_count = fee->err_count;
+
+ if (copy_to_user(buf, &info, sizeof(info)))
+ return -EFAULT;
+
+ return info.hdr.len;
+}
+
static int copy_fid_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh,
int info_type, const char *name,
size_t name_len,
@@ -530,6 +557,15 @@ static int copy_info_records_to_user(struct fanotify_event *event,
total_bytes += ret;
}
+ if (fanotify_is_error_event(event->mask)) {
+ ret = copy_error_info_to_user(event, buf, count);
+ if (ret < 0)
+ return ret;
+ buf += ret;
+ count -= ret;
+ total_bytes += ret;
+ }
+
return total_bytes;
}
diff --git a/include/uapi/linux/fanotify.h b/include/uapi/linux/fanotify.h
index 2990731ddc8bc..bd1932c2074d5 100644
--- a/include/uapi/linux/fanotify.h
+++ b/include/uapi/linux/fanotify.h
@@ -126,6 +126,7 @@ struct fanotify_event_metadata {
#define FAN_EVENT_INFO_TYPE_DFID_NAME 2
#define FAN_EVENT_INFO_TYPE_DFID 3
#define FAN_EVENT_INFO_TYPE_PIDFD 4
+#define FAN_EVENT_INFO_TYPE_ERROR 5
/* Variable length info record following event metadata */
struct fanotify_event_info_header {
@@ -160,6 +161,12 @@ struct fanotify_event_info_pidfd {
__s32 pidfd;
};
+struct fanotify_event_info_error {
+ struct fanotify_event_info_header hdr;
+ __s32 error;
+ __u32 error_count;
+};
+
struct fanotify_response {
__s32 fd;
__u32 response;
