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authorBartosz Golaszewski <bartosz.golaszewski@linaro.org>2022-11-23 12:24:16 +0100
committerChristoph Hellwig <hch@lst.de>2022-12-02 11:11:27 +0100
commit77992f896745c63ae64bfccfdc429ab7b3d88da5 (patch)
treeffb535f1104b37331fd4772c46cf574c90b4a0d9 /Documentation/filesystems
parentc65234b283a65cfbfc94619655e820a5e55199eb (diff)
downloadlinux-77992f896745c63ae64bfccfdc429ab7b3d88da5.tar.bz2
configfs: remove mentions of committable items
A proposition of implementation of committable items has been rejected due to the gpio-sim module being the only user and configfs not getting much development in general. In that case, let's remove the notion of committable items from docs and headers. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'Documentation/filesystems')
-rw-r--r--Documentation/filesystems/configfs.rst48
1 files changed, 0 insertions, 48 deletions
diff --git a/Documentation/filesystems/configfs.rst b/Documentation/filesystems/configfs.rst
index 1d3d6f4a82a9..8c9342ed6d25 100644
--- a/Documentation/filesystems/configfs.rst
+++ b/Documentation/filesystems/configfs.rst
@@ -289,7 +289,6 @@ config_item_type::
const char *name);
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,
@@ -486,50 +485,3 @@ up. Here, the heartbeat code calls configfs_depend_item(). If it
succeeds, then heartbeat knows the region is safe to give to ocfs2.
If it fails, it was being torn down anyway, and heartbeat can gracefully
pass up an error.
-
-Committable Items
-=================
-
-Note:
- Committable items are currently unimplemented.
-
-Some config_items cannot have a valid initial state. That is, no
-default values can be specified for the item's attributes such that the
-item can do its work. Userspace must configure one or more attributes,
-after which the subsystem can start whatever entity this item
-represents.
-
-Consider the FakeNBD device from above. Without a target address *and*
-a target device, the subsystem has no idea what block device to import.
-The simple example assumes that the subsystem merely waits until all the
-appropriate attributes are configured, and then connects. This will,
-indeed, work, but now every attribute store must check if the attributes
-are initialized. Every attribute store must fire off the connection if
-that condition is met.
-
-Far better would be an explicit action notifying the subsystem that the
-config_item is ready to go. More importantly, an explicit action allows
-the subsystem to provide feedback as to whether the attributes are
-initialized in a way that makes sense. configfs provides this as
-committable items.
-
-configfs still uses only normal filesystem operations. An item is
-committed via rename(2). The item is moved from a directory where it
-can be modified to a directory where it cannot.
-
-Any group that provides the ct_group_ops->commit_item() method has
-committable items. When this group appears in configfs, mkdir(2) will
-not work directly in the group. Instead, the group will have two
-subdirectories: "live" and "pending". The "live" directory does not
-support mkdir(2) or rmdir(2) either. It only allows rename(2). The
-"pending" directory does allow mkdir(2) and rmdir(2). An item is
-created in the "pending" directory. Its attributes can be modified at
-will. Userspace commits the item by renaming it into the "live"
-directory. At this point, the subsystem receives the ->commit_item()
-callback. If all required attributes are filled to satisfaction, the
-method returns zero and the item is moved to the "live" directory.
-
-As rmdir(2) does not work in the "live" directory, an item must be
-shutdown, or "uncommitted". Again, this is done via rename(2), this
-time from the "live" directory back to the "pending" one. The subsystem
-is notified by the ct_group_ops->uncommit_object() method.