[PATCH v8 20/32] fanotify: Dynamically resize the FAN_FS_ERROR pool
From: Gabriel Krisman Bertazi <hidden>
Date: 2021-10-19 00:03:09
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
Allow the FAN_FS_ERROR group mempool to grow up to an upper limit dynamically, instead of starting already at the limit. This doesn't bother resizing on mark removal, but next time a mark is added, the slot will be either reused or resized. Also, if several marks are being removed at once, most likely the group is going away anyway. Signed-off-by: Gabriel Krisman Bertazi <redacted> --- fs/notify/fanotify/fanotify_user.c | 26 +++++++++++++++++++++----- include/linux/fsnotify_backend.h | 1 + 2 files changed, 22 insertions(+), 5 deletions(-)
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index f77581c5b97f..a860c286e885 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c@@ -959,6 +959,10 @@ static int fanotify_remove_mark(struct fsnotify_group *group, removed = fanotify_mark_remove_from_mask(fsn_mark, mask, flags, umask, &destroy_mark); + + if (removed & FAN_FS_ERROR) + group->fanotify_data.error_event_marks--; + if (removed & fsnotify_conn_mask(fsn_mark->connector)) fsnotify_recalc_mask(fsn_mark->connector); if (destroy_mark)
@@ -1057,12 +1061,24 @@ static struct fsnotify_mark *fanotify_add_new_mark(struct fsnotify_group *group, static int fanotify_group_init_error_pool(struct fsnotify_group *group) { - if (mempool_initialized(&group->fanotify_data.error_events_pool)) - return 0; + int ret; + + if (group->fanotify_data.error_event_marks >= + FANOTIFY_DEFAULT_MAX_FEE_POOL) + return -ENOMEM; - return mempool_init_kmalloc_pool(&group->fanotify_data.error_events_pool, - FANOTIFY_DEFAULT_MAX_FEE_POOL, - sizeof(struct fanotify_error_event)); + if (!mempool_initialized(&group->fanotify_data.error_events_pool)) + ret = mempool_init_kmalloc_pool( + &group->fanotify_data.error_events_pool, + 1, sizeof(struct fanotify_error_event)); + else + ret = mempool_resize(&group->fanotify_data.error_events_pool, + group->fanotify_data.error_event_marks + 1); + + if (!ret) + group->fanotify_data.error_event_marks++; + + return ret; } static int fanotify_add_mark(struct fsnotify_group *group,
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 9941c06b8c8a..96e1d31394ce 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h@@ -247,6 +247,7 @@ struct fsnotify_group { int f_flags; /* event_f_flags from fanotify_init() */ struct ucounts *ucounts; mempool_t error_events_pool; + unsigned int error_event_marks; } fanotify_data; #endif /* CONFIG_FANOTIFY */ };
--
2.33.0