[PATCH v2 6/7] fsnotify: clean up fsnotify()
From: Miklos Szeredi
Date: Wed Oct 25 2017 - 04:42:39 EST
Use helpers to get first and next marks from connector.
Also get rid of inode_node/vfsmount_node local variables, which just refers
to the same objects as iter_info. There was an srcu_dereference() for
foo_node, but that's completely superfluous since we've already done it
when obtaining foo_node.
Also get rid of inode_group/vfsmount_group local variables; checking
against non-NULL for these is the same as checking against non-NULL
inode_mark/vfsmount_mark.
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
---
fs/notify/fsnotify.c | 113 ++++++++++++++++++++++++---------------------------
1 file changed, 54 insertions(+), 59 deletions(-)
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 0ab6a7179e4d..dcd70e94cbf1 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -243,6 +243,29 @@ static int send_to_group(struct inode *to_tell,
file_name, cookie, iter_info);
}
+static struct fsnotify_mark *fsnotify_first_mark(struct fsnotify_mark_connector **connp)
+{
+ struct fsnotify_mark_connector *conn;
+ struct hlist_node *node = NULL;
+
+ conn = srcu_dereference(*connp, &fsnotify_mark_srcu);
+ if (conn)
+ node = srcu_dereference(conn->list.first, &fsnotify_mark_srcu);
+
+ return hlist_entry_safe(node, struct fsnotify_mark, obj_list);
+}
+
+static struct fsnotify_mark *fsnotify_next_mark(struct fsnotify_mark *mark)
+{
+ struct hlist_node *node = NULL;
+
+ if (mark)
+ node = srcu_dereference(mark->obj_list.next,
+ &fsnotify_mark_srcu);
+
+ return hlist_entry_safe(node, struct fsnotify_mark, obj_list);
+}
+
/*
* This is the main call to fsnotify. The VFS calls into hook specific functions
* in linux/fsnotify.h. Those functions then in turn call here. Here will call
@@ -252,11 +275,7 @@ static int send_to_group(struct inode *to_tell,
int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
const unsigned char *file_name, u32 cookie)
{
- struct hlist_node *inode_node = NULL, *vfsmount_node = NULL;
- struct fsnotify_mark *inode_mark = NULL, *vfsmount_mark = NULL;
- struct fsnotify_group *inode_group, *vfsmount_group;
- struct fsnotify_mark_connector *inode_conn, *vfsmount_conn;
- struct fsnotify_iter_info iter_info;
+ struct fsnotify_iter_info iter_info = { NULL, NULL };
struct mount *mnt;
int ret = 0;
/* global tests shouldn't care about events on child only the specific event */
@@ -291,26 +310,16 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
if ((mask & FS_MODIFY) ||
(test_mask & to_tell->i_fsnotify_mask)) {
- inode_conn = srcu_dereference(to_tell->i_fsnotify_marks,
- &fsnotify_mark_srcu);
- if (inode_conn)
- inode_node = srcu_dereference(inode_conn->list.first,
- &fsnotify_mark_srcu);
+ iter_info.inode_mark =
+ fsnotify_first_mark(&to_tell->i_fsnotify_marks);
}
if (mnt && ((mask & FS_MODIFY) ||
(test_mask & mnt->mnt_fsnotify_mask))) {
- inode_conn = srcu_dereference(to_tell->i_fsnotify_marks,
- &fsnotify_mark_srcu);
- if (inode_conn)
- inode_node = srcu_dereference(inode_conn->list.first,
- &fsnotify_mark_srcu);
- vfsmount_conn = srcu_dereference(mnt->mnt_fsnotify_marks,
- &fsnotify_mark_srcu);
- if (vfsmount_conn)
- vfsmount_node = srcu_dereference(
- vfsmount_conn->list.first,
- &fsnotify_mark_srcu);
+ iter_info.inode_mark =
+ fsnotify_first_mark(&to_tell->i_fsnotify_marks);
+ iter_info.vfsmount_mark =
+ fsnotify_first_mark(&mnt->mnt_fsnotify_marks);
}
/*
@@ -318,41 +327,28 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
* ignore masks are properly reflected for mount mark notifications.
* That's why this traversal is so complicated...
*/
- while (inode_node || vfsmount_node) {
- inode_group = NULL;
- inode_mark = NULL;
- vfsmount_group = NULL;
- vfsmount_mark = NULL;
-
- if (inode_node) {
- inode_mark = hlist_entry(srcu_dereference(inode_node, &fsnotify_mark_srcu),
- struct fsnotify_mark, obj_list);
- inode_group = inode_mark->group;
- if (!(inode_mark->flags & FSNOTIFY_MARK_FLAG_ATTACHED))
- goto skip_inode;
- }
+ while (iter_info.inode_mark || iter_info.vfsmount_mark) {
+ struct fsnotify_mark *inode_mark = iter_info.inode_mark;
+ struct fsnotify_mark *vfsmount_mark = iter_info.vfsmount_mark;
- if (vfsmount_node) {
- vfsmount_mark = hlist_entry(srcu_dereference(vfsmount_node, &fsnotify_mark_srcu),
- struct fsnotify_mark, obj_list);
- vfsmount_group = vfsmount_mark->group;
- if (!(vfsmount_mark->flags & FSNOTIFY_MARK_FLAG_ATTACHED))
- goto skip_vfsmount;
+ if (inode_mark &&
+ !(inode_mark->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) {
+ vfsmount_mark = NULL;
+ goto skip;
+ }
+ if (vfsmount_mark &&
+ !(vfsmount_mark->flags & FSNOTIFY_MARK_FLAG_ATTACHED)) {
+ inode_mark = NULL;
+ goto skip;
}
- iter_info.inode_mark = inode_mark;
- iter_info.vfsmount_mark = vfsmount_mark;
-
- if (inode_group && vfsmount_group) {
- int cmp = fsnotify_compare_groups(inode_group,
- vfsmount_group);
- if (cmp > 0) {
- inode_group = NULL;
+ if (inode_mark && vfsmount_mark) {
+ int cmp = fsnotify_compare_groups(inode_mark->group,
+ vfsmount_mark->group);
+ if (cmp > 0)
inode_mark = NULL;
- } else if (cmp < 0) {
- vfsmount_group = NULL;
+ else if (cmp < 0)
vfsmount_mark = NULL;
- }
}
ret = send_to_group(to_tell, inode_mark, vfsmount_mark, mask,
@@ -361,14 +357,13 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS))
goto out;
-skip_inode:
- if (inode_group)
- inode_node = srcu_dereference(inode_node->next,
- &fsnotify_mark_srcu);
-skip_vfsmount:
- if (vfsmount_group)
- vfsmount_node = srcu_dereference(vfsmount_node->next,
- &fsnotify_mark_srcu);
+skip:
+ if (inode_mark)
+ iter_info.inode_mark =
+ fsnotify_next_mark(iter_info.inode_mark);
+ if (vfsmount_mark)
+ iter_info.vfsmount_mark =
+ fsnotify_next_mark(iter_info.vfsmount_mark);
}
ret = 0;
out:
--
2.5.5