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| author | Jan Kara <jack@suse.cz> | 2016-11-10 16:02:11 +0100 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2017-04-10 17:37:36 +0200 |
| commit | abc77577a669f424c5d0c185b9994f2621c52aa4 (patch) | |
| tree | a7e18bc2c8229a8a634d899445c33958f8967876 /include/linux/fsnotify_backend.h | |
| parent | f09b04a03e0239f65bd964a1de758e53cf6349e8 (diff) | |
| download | linux-0-day-abc77577a669f424c5d0c185b9994f2621c52aa4.tar.gz linux-0-day-abc77577a669f424c5d0c185b9994f2621c52aa4.tar.xz | |
fsnotify: Provide framework for dropping SRCU lock in ->handle_event
fanotify wants to drop fsnotify_mark_srcu lock when waiting for response
from userspace so that the whole notification subsystem is not blocked
during that time. This patch provides a framework for safely getting
mark reference for a mark found in the object list which pins the mark
in that list. We can then drop fsnotify_mark_srcu, wait for userspace
response and then safely continue iteration of the object list once we
reaquire fsnotify_mark_srcu.
Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'include/linux/fsnotify_backend.h')
| -rw-r--r-- | include/linux/fsnotify_backend.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index a483614b25d05..5bb6d988b9f63 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -80,6 +80,7 @@ struct fsnotify_event; struct fsnotify_mark; struct fsnotify_event_private_data; struct fsnotify_fname; +struct fsnotify_iter_info; /* * Each group much define these ops. The fsnotify infrastructure will call @@ -163,6 +164,8 @@ struct fsnotify_group { struct fsnotify_event *overflow_event; /* Event we queue when the * notification list is too * full */ + atomic_t user_waits; /* Number of tasks waiting for user + * response */ /* groups can define private fields here or use the void *private */ union { @@ -368,6 +371,8 @@ extern void fsnotify_clear_marks_by_group_flags(struct fsnotify_group *group, un extern void fsnotify_get_mark(struct fsnotify_mark *mark); extern void fsnotify_put_mark(struct fsnotify_mark *mark); extern void fsnotify_unmount_inodes(struct super_block *sb); +extern void fsnotify_finish_user_wait(struct fsnotify_iter_info *iter_info); +extern bool fsnotify_prepare_user_wait(struct fsnotify_iter_info *iter_info); /* put here because inotify does some weird stuff when destroying watches */ extern void fsnotify_init_event(struct fsnotify_event *event, |