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authorLinus Torvalds2019-05-07 13:01:40 -0700
committerLinus Torvalds2019-05-07 13:01:40 -0700
commitcf482a49af564a3044de3178ea28f10ad5921b38 (patch)
treeb3ce61fc005f73ac6b7b3dfe4b1a4501910bde51 /Documentation/filesystems
parent01e5d1830cf54ac45768ef9ceb3e79cea2e1198c (diff)
parent70e16a620e075cb916644e06012766639b58b2fb (diff)
Merge tag 'driver-core-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core/kobject updates from Greg KH: "Here is the "big" set of driver core patches for 5.2-rc1 There are a number of ACPI patches in here as well, as Rafael said they should go through this tree due to the driver core changes they required. They have all been acked by the ACPI developers. There are also a number of small subsystem-specific changes in here, due to some changes to the kobject core code. Those too have all been acked by the various subsystem maintainers. As for content, it's pretty boring outside of the ACPI changes: - spdx cleanups - kobject documentation updates - default attribute groups for kobjects - other minor kobject/driver core fixes All have been in linux-next for a while with no reported issues" * tag 'driver-core-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (47 commits) kobject: clean up the kobject add documentation a bit more kobject: Fix kernel-doc comment first line kobject: Remove docstring reference to kset firmware_loader: Fix a typo ("syfs" -> "sysfs") kobject: fix dereference before null check on kobj Revert "driver core: platform: Fix the usage of platform device name(pdev->name)" init/config: Do not select BUILD_BIN2C for IKCONFIG Provide in-kernel headers to make extending kernel easier kobject: Improve doc clarity kobject_init_and_add() kobject: Improve docs for kobject_add/del driver core: platform: Fix the usage of platform device name(pdev->name) livepatch: Replace klp_ktype_patch's default_attrs with groups cpufreq: schedutil: Replace default_attrs field with groups padata: Replace padata_attr_type default_attrs field with groups irqdesc: Replace irq_kobj_type's default_attrs field with groups net-sysfs: Replace ktype default_attrs field with groups block: Replace all ktype default_attrs with groups samples/kobject: Replace foo_ktype's default_attrs field with groups kobject: Add support for default attribute groups to kobj_type driver core: Postpone DMA tear-down until after devres release for probe failure ...
Diffstat (limited to 'Documentation/filesystems')
-rw-r--r--Documentation/filesystems/debugfs.txt16
1 files changed, 9 insertions, 7 deletions
diff --git a/Documentation/filesystems/debugfs.txt b/Documentation/filesystems/debugfs.txt
index 4f45f71149cb..4a0a9c3f4af6 100644
--- a/Documentation/filesystems/debugfs.txt
+++ b/Documentation/filesystems/debugfs.txt
@@ -31,10 +31,10 @@ This call, if successful, will make a directory called name underneath the
indicated parent directory. If parent is NULL, the directory will be
created in the debugfs root. On success, the return value is a struct
dentry pointer which can be used to create files in the directory (and to
-clean it up at the end). A NULL return value indicates that something went
-wrong. If ERR_PTR(-ENODEV) is returned, that is an indication that the
-kernel has been built without debugfs support and none of the functions
-described below will work.
+clean it up at the end). An ERR_PTR(-ERROR) return value indicates that
+something went wrong. If ERR_PTR(-ENODEV) is returned, that is an
+indication that the kernel has been built without debugfs support and none
+of the functions described below will work.
The most general way to create a file within a debugfs directory is with:
@@ -48,8 +48,9 @@ should hold the file, data will be stored in the i_private field of the
resulting inode structure, and fops is a set of file operations which
implement the file's behavior. At a minimum, the read() and/or write()
operations should be provided; others can be included as needed. Again,
-the return value will be a dentry pointer to the created file, NULL for
-error, or ERR_PTR(-ENODEV) if debugfs support is missing.
+the return value will be a dentry pointer to the created file,
+ERR_PTR(-ERROR) on error, or ERR_PTR(-ENODEV) if debugfs support is
+missing.
Create a file with an initial size, the following function can be used
instead:
@@ -214,7 +215,8 @@ can be removed with:
void debugfs_remove(struct dentry *dentry);
-The dentry value can be NULL, in which case nothing will be removed.
+The dentry value can be NULL or an error value, in which case nothing will
+be removed.
Once upon a time, debugfs users were required to remember the dentry
pointer for every debugfs file they created so that all files could be