From 8a6ae64132fd27a944faed7bc38484827609eb76 Mon Sep 17 00:00:00 2001 From: Gabriel Krisman Bertazi Date: Mon, 25 Oct 2021 16:27:36 -0300 Subject: [PATCH] fanotify: Support merging of error events 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. Link: https://lore.kernel.org/r/20211025192746.66445-22-krisman@collabora.com Reviewed-by: Amir Goldstein Reviewed-by: Jan Kara Signed-off-by: Gabriel Krisman Bertazi Signed-off-by: Jan Kara --- 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 1f195c9..cedcb15 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 ebef952..2b032b7 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)); } -- 2.7.4