From 8c1934c8d70b22ca8333b216aec6c7d09fdbd6a6 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Wed, 28 Jul 2010 10:18:37 -0400 Subject: inotify: allow users to request not to recieve events on unlinked children An inotify watch on a directory will send events for children even if those children have been unlinked. This patch add a new inotify flag IN_EXCL_UNLINK which allows a watch to specificy they don't care about unlinked children. This should fix performance problems seen by tasks which add a watch to /tmp and then are overrun with events when other processes are reading and writing to unlinked files they created in /tmp. https://bugzilla.kernel.org/show_bug.cgi?id=16296 Requested-by: Matthias Clasen Signed-off-by: Eric Paris --- fs/notify/inotify/inotify_fsnotify.c | 9 +++++++++ fs/notify/inotify/inotify_user.c | 2 +- include/linux/fsnotify_backend.h | 1 + include/linux/inotify.h | 1 + 4 files changed, 12 insertions(+), 1 deletion(-) diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c index 388a150c3d4a..9d332e7f5a5c 100644 --- a/fs/notify/inotify/inotify_fsnotify.c +++ b/fs/notify/inotify/inotify_fsnotify.c @@ -22,6 +22,7 @@ * General Public License for more details. */ +#include /* d_unlinked */ #include /* struct inode */ #include #include @@ -157,6 +158,14 @@ static bool inotify_should_send_event(struct fsnotify_group *group, struct inode mask = (mask & ~FS_EVENT_ON_CHILD); send = (fsn_mark->mask & mask); + if (send && (fsn_mark->mask & FS_EXCL_UNLINK) && + (data_type == FSNOTIFY_EVENT_PATH)) { + struct path *path = data; + + if (d_unlinked(path->dentry)) + send = false; + } + /* find took a reference */ fsnotify_put_mark(fsn_mark); diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c index f381dafe8efb..dfc80f70e517 100644 --- a/fs/notify/inotify/inotify_user.c +++ b/fs/notify/inotify/inotify_user.c @@ -97,7 +97,7 @@ static inline __u32 inotify_arg_to_mask(u32 arg) mask = (FS_IN_IGNORED | FS_EVENT_ON_CHILD | FS_UNMOUNT); /* mask off the flags used to open the fd */ - mask |= (arg & (IN_ALL_EVENTS | IN_ONESHOT)); + mask |= (arg & (IN_ALL_EVENTS | IN_ONESHOT | IN_EXCL_UNLINK)); return mask; } diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index b9b3f24ad4fc..4b809fcd4996 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -44,6 +44,7 @@ #define FS_OPEN_PERM 0x00010000 /* open event in an permission hook */ #define FS_ACCESS_PERM 0x00020000 /* access event in a permissions hook */ +#define FS_EXCL_UNLINK 0x04000000 /* do not send events if object is unlinked */ #define FS_IN_ISDIR 0x40000000 /* event occurred against dir */ #define FS_IN_ONESHOT 0x80000000 /* only send event once */ diff --git a/include/linux/inotify.h b/include/linux/inotify.h index 94d209a1b689..b74f2ef2c368 100644 --- a/include/linux/inotify.h +++ b/include/linux/inotify.h @@ -51,6 +51,7 @@ struct inotify_event { /* special flags */ #define IN_ONLYDIR 0x01000000 /* only watch the path if it is a directory */ #define IN_DONT_FOLLOW 0x02000000 /* don't follow a sym link */ +#define IN_EXCL_UNLINK 0x04000000 /* exclude events on unlinked objects */ #define IN_MASK_ADD 0x20000000 /* add to the mask of an already existing watch */ #define IN_ISDIR 0x40000000 /* event occurred against dir */ #define IN_ONESHOT 0x80000000 /* only send event once */ -- cgit v1.2.2