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author | Joel Becker <joel.becker@oracle.com> | 2006-10-07 00:33:23 (GMT) |
---|---|---|
committer | Mark Fasheh <mark.fasheh@oracle.com> | 2007-07-11 00:11:01 (GMT) |
commit | 299894cc9001b09e3e9685f2709b49e7e1092ccc (patch) | |
tree | 2a2e9bb69d2393bf620a34daea17e52ed9f9e5d7 /Documentation/filesystems/configfs/configfs.txt | |
parent | 6d748924b753d63a57dad130fdf11f64c27ff54b (diff) | |
download | linux-fsl-qoriq-299894cc9001b09e3e9685f2709b49e7e1092ccc.tar.xz |
configfs: accessing item hierarchy during rmdir(2)
Add a notification callback, ops->disconnect_notify(). It has the same
prototype as ->drop_item(), but it will be called just before the item
linkage is broken. This way, configfs users who want to do work while
the object is still in the heirarchy have a chance.
Client drivers will still need to config_item_put() in their
->drop_item(), if they implement it. They need do nothing in
->disconnect_notify(). They don't have to provide it if they don't
care. But someone who wants to be notified before ci_parent is set to
NULL can now be notified.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Diffstat (limited to 'Documentation/filesystems/configfs/configfs.txt')
-rw-r--r-- | Documentation/filesystems/configfs/configfs.txt | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/filesystems/configfs/configfs.txt b/Documentation/filesystems/configfs/configfs.txt index 21f038e..aef74cd 100644 --- a/Documentation/filesystems/configfs/configfs.txt +++ b/Documentation/filesystems/configfs/configfs.txt @@ -238,6 +238,8 @@ config_item_type. struct config_group *(*make_group)(struct config_group *group, const char *name); int (*commit_item)(struct config_item *item); + void (*disconnect_notify)(struct config_group *group, + struct config_item *item); void (*drop_item)(struct config_group *group, struct config_item *item); }; @@ -268,6 +270,16 @@ the item in other threads, the memory is safe. It may take some time for the item to actually disappear from the subsystem's usage. But it is gone from configfs. +When drop_item() is called, the item's linkage has already been torn +down. It no longer has a reference on its parent and has no place in +the item hierarchy. If a client needs to do some cleanup before this +teardown happens, the subsystem can implement the +ct_group_ops->disconnect_notify() method. The method is called after +configfs has removed the item from the filesystem view but before the +item is removed from its parent group. Like drop_item(), +disconnect_notify() is void and cannot fail. Client subsystems should +not drop any references here, as they still must do it in drop_item(). + A config_group cannot be removed while it still has child items. This is implemented in the configfs rmdir(2) code. ->drop_item() will not be called, as the item has not been dropped. rmdir(2) will fail, as the |