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author | Chris Zankel <chris@zankel.net> | 2015-08-29 23:55:58 (GMT) |
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committer | Chris Zankel <chris@zankel.net> | 2015-08-29 23:55:58 (GMT) |
commit | 650c919798c71fb34b77a6f2ba03a06907f06a76 (patch) | |
tree | d1c60012d4d86846d25f1d0b783b5122c26a2e31 /fs/notify/mark.c | |
parent | 895fb3159280fe7695b35ec7c87ec19e13ca5b6e (diff) | |
parent | 64291f7db5bd8150a74ad2036f1037e6a0428df2 (diff) | |
download | linux-650c919798c71fb34b77a6f2ba03a06907f06a76.tar.xz |
Merge tag 'v4.2' into for_next
Linux 4.2
Diffstat (limited to 'fs/notify/mark.c')
-rw-r--r-- | fs/notify/mark.c | 30 |
1 files changed, 25 insertions, 5 deletions
diff --git a/fs/notify/mark.c b/fs/notify/mark.c index 92e48c7..39ddcaf 100644 --- a/fs/notify/mark.c +++ b/fs/notify/mark.c @@ -412,16 +412,36 @@ void fsnotify_clear_marks_by_group_flags(struct fsnotify_group *group, unsigned int flags) { struct fsnotify_mark *lmark, *mark; + LIST_HEAD(to_free); + /* + * We have to be really careful here. Anytime we drop mark_mutex, e.g. + * fsnotify_clear_marks_by_inode() can come and free marks. Even in our + * to_free list so we have to use mark_mutex even when accessing that + * list. And freeing mark requires us to drop mark_mutex. So we can + * reliably free only the first mark in the list. That's why we first + * move marks to free to to_free list in one go and then free marks in + * to_free list one by one. + */ mutex_lock_nested(&group->mark_mutex, SINGLE_DEPTH_NESTING); list_for_each_entry_safe(mark, lmark, &group->marks_list, g_list) { - if (mark->flags & flags) { - fsnotify_get_mark(mark); - fsnotify_destroy_mark_locked(mark, group); - fsnotify_put_mark(mark); - } + if (mark->flags & flags) + list_move(&mark->g_list, &to_free); } mutex_unlock(&group->mark_mutex); + + while (1) { + mutex_lock_nested(&group->mark_mutex, SINGLE_DEPTH_NESTING); + if (list_empty(&to_free)) { + mutex_unlock(&group->mark_mutex); + break; + } + mark = list_first_entry(&to_free, struct fsnotify_mark, g_list); + fsnotify_get_mark(mark); + fsnotify_destroy_mark_locked(mark, group); + mutex_unlock(&group->mark_mutex); + fsnotify_put_mark(mark); + } } /* |