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fsnotify: clean up fsnotify()

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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.

Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
This commit is contained in:
Miklos Szeredi 2017-10-30 21:14:56 +01:00 committed by Jan Kara
parent f37650f1c7
commit 3427ce7155
1 changed files with 44 additions and 59 deletions
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103
fs/notify/fsnotify.c
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@ -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 = {};
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 +327,17 @@ 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;
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 (inode_node) {
inode_mark = hlist_entry(srcu_dereference(inode_node, &fsnotify_mark_srcu),
struct fsnotify_mark, obj_list);
inode_group = inode_mark->group;
}
if (vfsmount_node) {
vfsmount_mark = hlist_entry(srcu_dereference(vfsmount_node, &fsnotify_mark_srcu),
struct fsnotify_mark, obj_list);
vfsmount_group = vfsmount_mark->group;
}
/*
* Need to protect both marks against freeing so that we can
* continue iteration from this place, regardless of which mark
* we actually happen to send an event for.
*/
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,
@ -362,12 +347,12 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS))
goto out;
if (inode_group)
inode_node = srcu_dereference(inode_node->next,
&fsnotify_mark_srcu);
if (vfsmount_group)
vfsmount_node = srcu_dereference(vfsmount_node->next,
&fsnotify_mark_srcu);
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: