diff mbox series

[v8,22/32] fanotify: Support merging of error events

Message ID 20211019000015.1666608-23-krisman@collabora.com (mailing list archive)
State New, archived
Headers show
Series file system-wide error monitoring | expand

Commit Message

Gabriel Krisman Bertazi Oct. 19, 2021, midnight UTC 
Error events (FAN_FS_ERROR) against the same file system can be merged
by simply iterating the error count.  The hash is taken from the fsid,
without considering the FH.  This means that only the first error object
is reported.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>

---
Changes since v7:
  - Move fee->fsid assignment here (Amir)
  - Open code error event merge logic in fanotify_merge (Jan)
---
 fs/notify/fanotify/fanotify.c | 26 ++++++++++++++++++++++++--
 fs/notify/fanotify/fanotify.h |  4 +++-
 2 files changed, 27 insertions(+), 3 deletions(-)

Comments

Amir Goldstein Oct. 19, 2021, 5:56 a.m. UTC | #1 
On Tue, Oct 19, 2021 at 3:03 AM Gabriel Krisman Bertazi
<krisman@collabora.com> wrote:
>
> Error events (FAN_FS_ERROR) against the same file system can be merged
> by simply iterating the error count.  The hash is taken from the fsid,
> without considering the FH.  This means that only the first error object
> is reported.
>
> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>

> ---
> Changes since v7:
>   - Move fee->fsid assignment here (Amir)
>   - Open code error event merge logic in fanotify_merge (Jan)
> ---
>  fs/notify/fanotify/fanotify.c | 26 ++++++++++++++++++++++++--
>  fs/notify/fanotify/fanotify.h |  4 +++-
>  2 files changed, 27 insertions(+), 3 deletions(-)
>
> diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
> index 1f195c95dfcd..cedcb1546804 100644
> --- a/fs/notify/fanotify/fanotify.c
> +++ b/fs/notify/fanotify/fanotify.c
> @@ -111,6 +111,16 @@ static bool fanotify_name_event_equal(struct fanotify_name_event *fne1,
>         return fanotify_info_equal(info1, info2);
>  }
>
> +static bool fanotify_error_event_equal(struct fanotify_error_event *fee1,
> +                                      struct fanotify_error_event *fee2)
> +{
> +       /* Error events against the same file system are always merged. */
> +       if (!fanotify_fsid_equal(&fee1->fsid, &fee2->fsid))
> +               return false;
> +
> +       return true;
> +}
> +
>  static bool fanotify_should_merge(struct fanotify_event *old,
>                                   struct fanotify_event *new)
>  {
> @@ -141,6 +151,9 @@ static bool fanotify_should_merge(struct fanotify_event *old,
>         case FANOTIFY_EVENT_TYPE_FID_NAME:
>                 return fanotify_name_event_equal(FANOTIFY_NE(old),
>                                                  FANOTIFY_NE(new));
> +       case FANOTIFY_EVENT_TYPE_FS_ERROR:
> +               return fanotify_error_event_equal(FANOTIFY_EE(old),
> +                                                 FANOTIFY_EE(new));
>         default:
>                 WARN_ON_ONCE(1);
>         }
> @@ -176,6 +189,10 @@ static int fanotify_merge(struct fsnotify_group *group,
>                         break;
>                 if (fanotify_should_merge(old, new)) {
>                         old->mask |= new->mask;
> +
> +                       if (fanotify_is_error_event(old->mask))
> +                               FANOTIFY_EE(old)->err_count++;
> +
>                         return 1;
>                 }
>         }
> @@ -577,7 +594,8 @@ static struct fanotify_event *fanotify_alloc_name_event(struct inode *id,
>  static struct fanotify_event *fanotify_alloc_error_event(
>                                                 struct fsnotify_group *group,
>                                                 __kernel_fsid_t *fsid,
> -                                               const void *data, int data_type)
> +                                               const void *data, int data_type,
> +                                               unsigned int *hash)
>  {
>         struct fs_error_report *report =
>                         fsnotify_data_error_report(data, data_type);
> @@ -591,6 +609,10 @@ static struct fanotify_event *fanotify_alloc_error_event(
>                 return NULL;
>
>         fee->fae.type = FANOTIFY_EVENT_TYPE_FS_ERROR;
> +       fee->err_count = 1;
> +       fee->fsid = *fsid;
> +
> +       *hash ^= fanotify_hash_fsid(fsid);
>
>         return &fee->fae;
>  }
> @@ -664,7 +686,7 @@ static struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,
>                 event = fanotify_alloc_perm_event(path, gfp);
>         } else if (fanotify_is_error_event(mask)) {
>                 event = fanotify_alloc_error_event(group, fsid, data,
> -                                                  data_type);
> +                                                  data_type, &hash);
>         } else if (name_event && (file_name || child)) {
>                 event = fanotify_alloc_name_event(id, fsid, file_name, child,
>                                                   &hash, gfp);
> diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
> index ebef952481fa..2b032b79d5b0 100644
> --- a/fs/notify/fanotify/fanotify.h
> +++ b/fs/notify/fanotify/fanotify.h
> @@ -199,6 +199,9 @@ FANOTIFY_NE(struct fanotify_event *event)
>
>  struct fanotify_error_event {
>         struct fanotify_event fae;
> +       u32 err_count; /* Suppressed errors count */
> +
> +       __kernel_fsid_t fsid; /* FSID this error refers to. */
>  };
>
>  static inline struct fanotify_error_event *
> @@ -332,7 +335,6 @@ static inline struct path *fanotify_event_path(struct fanotify_event *event)
>  static inline bool fanotify_is_hashed_event(u32 mask)
>  {
>         return !(fanotify_is_perm_event(mask) ||
> -                fanotify_is_error_event(mask) ||
>                  fsnotify_is_overflow_event(mask));
>  }
>
> --
> 2.33.0
>
Jan Kara Oct. 19, 2021, 1:52 p.m. UTC | #2 
On Mon 18-10-21 21:00:05, Gabriel Krisman Bertazi wrote:
> Error events (FAN_FS_ERROR) against the same file system can be merged
> by simply iterating the error count.  The hash is taken from the fsid,
> without considering the FH.  This means that only the first error object
> is reported.
> 
> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>

Looks good to me. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza


> ---
> Changes since v7:
>   - Move fee->fsid assignment here (Amir)
>   - Open code error event merge logic in fanotify_merge (Jan)
> ---
>  fs/notify/fanotify/fanotify.c | 26 ++++++++++++++++++++++++--
>  fs/notify/fanotify/fanotify.h |  4 +++-
>  2 files changed, 27 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
> index 1f195c95dfcd..cedcb1546804 100644
> --- a/fs/notify/fanotify/fanotify.c
> +++ b/fs/notify/fanotify/fanotify.c
> @@ -111,6 +111,16 @@ static bool fanotify_name_event_equal(struct fanotify_name_event *fne1,
>  	return fanotify_info_equal(info1, info2);
>  }
>  
> +static bool fanotify_error_event_equal(struct fanotify_error_event *fee1,
> +				       struct fanotify_error_event *fee2)
> +{
> +	/* Error events against the same file system are always merged. */
> +	if (!fanotify_fsid_equal(&fee1->fsid, &fee2->fsid))
> +		return false;
> +
> +	return true;
> +}
> +
>  static bool fanotify_should_merge(struct fanotify_event *old,
>  				  struct fanotify_event *new)
>  {
> @@ -141,6 +151,9 @@ static bool fanotify_should_merge(struct fanotify_event *old,
>  	case FANOTIFY_EVENT_TYPE_FID_NAME:
>  		return fanotify_name_event_equal(FANOTIFY_NE(old),
>  						 FANOTIFY_NE(new));
> +	case FANOTIFY_EVENT_TYPE_FS_ERROR:
> +		return fanotify_error_event_equal(FANOTIFY_EE(old),
> +						  FANOTIFY_EE(new));
>  	default:
>  		WARN_ON_ONCE(1);
>  	}
> @@ -176,6 +189,10 @@ static int fanotify_merge(struct fsnotify_group *group,
>  			break;
>  		if (fanotify_should_merge(old, new)) {
>  			old->mask |= new->mask;
> +
> +			if (fanotify_is_error_event(old->mask))
> +				FANOTIFY_EE(old)->err_count++;
> +
>  			return 1;
>  		}
>  	}
> @@ -577,7 +594,8 @@ static struct fanotify_event *fanotify_alloc_name_event(struct inode *id,
>  static struct fanotify_event *fanotify_alloc_error_event(
>  						struct fsnotify_group *group,
>  						__kernel_fsid_t *fsid,
> -						const void *data, int data_type)
> +						const void *data, int data_type,
> +						unsigned int *hash)
>  {
>  	struct fs_error_report *report =
>  			fsnotify_data_error_report(data, data_type);
> @@ -591,6 +609,10 @@ static struct fanotify_event *fanotify_alloc_error_event(
>  		return NULL;
>  
>  	fee->fae.type = FANOTIFY_EVENT_TYPE_FS_ERROR;
> +	fee->err_count = 1;
> +	fee->fsid = *fsid;
> +
> +	*hash ^= fanotify_hash_fsid(fsid);
>  
>  	return &fee->fae;
>  }
> @@ -664,7 +686,7 @@ static struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,
>  		event = fanotify_alloc_perm_event(path, gfp);
>  	} else if (fanotify_is_error_event(mask)) {
>  		event = fanotify_alloc_error_event(group, fsid, data,
> -						   data_type);
> +						   data_type, &hash);
>  	} else if (name_event && (file_name || child)) {
>  		event = fanotify_alloc_name_event(id, fsid, file_name, child,
>  						  &hash, gfp);
> diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
> index ebef952481fa..2b032b79d5b0 100644
> --- a/fs/notify/fanotify/fanotify.h
> +++ b/fs/notify/fanotify/fanotify.h
> @@ -199,6 +199,9 @@ FANOTIFY_NE(struct fanotify_event *event)
>  
>  struct fanotify_error_event {
>  	struct fanotify_event fae;
> +	u32 err_count; /* Suppressed errors count */
> +
> +	__kernel_fsid_t fsid; /* FSID this error refers to. */
>  };
>  
>  static inline struct fanotify_error_event *
> @@ -332,7 +335,6 @@ static inline struct path *fanotify_event_path(struct fanotify_event *event)
>  static inline bool fanotify_is_hashed_event(u32 mask)
>  {
>  	return !(fanotify_is_perm_event(mask) ||
> -		 fanotify_is_error_event(mask) ||
>  		 fsnotify_is_overflow_event(mask));
>  }
>  
> -- 
> 2.33.0
>
diff mbox series

Patch

diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 1f195c95dfcd..cedcb1546804 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -111,6 +111,16 @@  static bool fanotify_name_event_equal(struct fanotify_name_event *fne1,
 	return fanotify_info_equal(info1, info2);
 }
 
+static bool fanotify_error_event_equal(struct fanotify_error_event *fee1,
+				       struct fanotify_error_event *fee2)
+{
+	/* Error events against the same file system are always merged. */
+	if (!fanotify_fsid_equal(&fee1->fsid, &fee2->fsid))
+		return false;
+
+	return true;
+}
+
 static bool fanotify_should_merge(struct fanotify_event *old,
 				  struct fanotify_event *new)
 {
@@ -141,6 +151,9 @@  static bool fanotify_should_merge(struct fanotify_event *old,
 	case FANOTIFY_EVENT_TYPE_FID_NAME:
 		return fanotify_name_event_equal(FANOTIFY_NE(old),
 						 FANOTIFY_NE(new));
+	case FANOTIFY_EVENT_TYPE_FS_ERROR:
+		return fanotify_error_event_equal(FANOTIFY_EE(old),
+						  FANOTIFY_EE(new));
 	default:
 		WARN_ON_ONCE(1);
 	}
@@ -176,6 +189,10 @@  static int fanotify_merge(struct fsnotify_group *group,
 			break;
 		if (fanotify_should_merge(old, new)) {
 			old->mask |= new->mask;
+
+			if (fanotify_is_error_event(old->mask))
+				FANOTIFY_EE(old)->err_count++;
+
 			return 1;
 		}
 	}
@@ -577,7 +594,8 @@  static struct fanotify_event *fanotify_alloc_name_event(struct inode *id,
 static struct fanotify_event *fanotify_alloc_error_event(
 						struct fsnotify_group *group,
 						__kernel_fsid_t *fsid,
-						const void *data, int data_type)
+						const void *data, int data_type,
+						unsigned int *hash)
 {
 	struct fs_error_report *report =
 			fsnotify_data_error_report(data, data_type);
@@ -591,6 +609,10 @@  static struct fanotify_event *fanotify_alloc_error_event(
 		return NULL;
 
 	fee->fae.type = FANOTIFY_EVENT_TYPE_FS_ERROR;
+	fee->err_count = 1;
+	fee->fsid = *fsid;
+
+	*hash ^= fanotify_hash_fsid(fsid);
 
 	return &fee->fae;
 }
@@ -664,7 +686,7 @@  static struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,
 		event = fanotify_alloc_perm_event(path, gfp);
 	} else if (fanotify_is_error_event(mask)) {
 		event = fanotify_alloc_error_event(group, fsid, data,
-						   data_type);
+						   data_type, &hash);
 	} else if (name_event && (file_name || child)) {
 		event = fanotify_alloc_name_event(id, fsid, file_name, child,
 						  &hash, gfp);
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index ebef952481fa..2b032b79d5b0 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -199,6 +199,9 @@  FANOTIFY_NE(struct fanotify_event *event)
 
 struct fanotify_error_event {
 	struct fanotify_event fae;
+	u32 err_count; /* Suppressed errors count */
+
+	__kernel_fsid_t fsid; /* FSID this error refers to. */
 };
 
 static inline struct fanotify_error_event *
@@ -332,7 +335,6 @@  static inline struct path *fanotify_event_path(struct fanotify_event *event)
 static inline bool fanotify_is_hashed_event(u32 mask)
 {
 	return !(fanotify_is_perm_event(mask) ||
-		 fanotify_is_error_event(mask) ||
 		 fsnotify_is_overflow_event(mask));
 }