debugfs: dont stop on first failed recursive delete debugfs: dont stop on first failed recursive delete While running a while loop of removing a module that removes a debugfs directory with debugfs_remove_recursive, and at the same time doing a while loop of cat of a file in that directory, I would hit a point where somehow the cat of the file caused the remove to fail. The result is that other files did not get removed when the module was removed. I simple read of one of those file can oops the kernel because the operations to the file no longer exist (removed by module). The funny thing is that the file being cat'ed was removed. It was the siblings that were not. I see in the code to debugfs_remove_recursive there's a test that checks if the child fails to bail out of the loop to prevent an infinite loop. What this patch does is to still try any siblings in that directory. If all the siblings fail, or there are no more siblings, then we exit the loop. This fixes the above symptom, but... This is no full proof. It makes the debugfs_remove_recursive a bit more robust, but it does not explain why the one file failed. There may be some kind of delay deletion that makes the debugfs think it did not succeed. So this patch is more of a fix for the symptom but not the disease. This patch still makes the debugfs_remove_recursive more robust and until I can find out why the bug exists, this patch will keep the kernel from oopsing in most cases. Even after the cause is found I think this change can stand on its own and should be kept. [ Impact: prevent kernel oops on module unload and reading debugfs files ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
debugfs: function to know if debugfs is initialized Impact: add new debugfs API With ftrace, some tracers are registered in early initcalls and attempt to create files on the debugfs filesystem. Depending on when they are activated, they can try to create their file at any time. Some checks can be done on the tracing area but providing a helper to know if debugfs is registered make it really more easy. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1237759847-21025-2-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
integrity: special fs magic Discussion on the mailing list questioned the use of these magic values in userspace, concluding these values are already exported to userspace via statfs and their correct/incorrect usage is left up to the userspace application. - Move special fs magic number definitions to magic.h - Add magic.h include Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: James Morris <jmorris@namei.org>
debugfs: Implement debugfs_remove_recursive() debugfs_remove_recursive() will remove a dentry and all its children. Drivers can use this to zap their whole debugfs tree so that they don't need to keep track of every single debugfs dentry they created. It may fail to remove the whole tree in certain cases: sh-3.2# rmmod atmel-mci < /sys/kernel/debug/mmc0/ios/clock mmc0: card b368 removed atmel_mci atmel_mci.0: Lost dma0chan1, falling back to PIO sh-3.2# ls /sys/kernel/debug/mmc0/ ios But I'm not sure if that case can be handled in any sane manner. Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> Cc: Pierre Ossman <drzeus-list@drzeus.cx> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
debugfs: fix sparse warnings extern does not belong in C files, move declaration to linux/debugfs.h fs/debugfs/file.c:42:30: warning: symbol 'debugfs_file_operations' was not declared. Should it be static? fs/debugfs/file.c:54:31: warning: symbol 'debugfs_link_operations' was not declared. Should it be static? Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Kobject: convert fs/* from kobject_unregister() to kobject_put() There is no need for kobject_unregister() anymore, thanks to Kay's kobject cleanup changes, so replace all instances of it with kobject_put(). Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
kobject: convert kernel_kset to be a kobject kernel_kset does not need to be a kset, but a much simpler kobject now that we have kobj_attributes. We also rename kernel_kset to kernel_kobj to catch all users of this symbol with a build error instead of an easy-to-ignore build warning. Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
kset: convert kernel_subsys to use kset_create Dynamically create the kset instead of declaring it statically. We also rename kernel_subsys to kernel_kset to catch all users of this symbol with a build error instead of an easy-to-ignore build warning. Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
kobject: remove struct kobj_type from struct kset We don't need a "default" ktype for a kset. We should set this explicitly every time for each kset. This change is needed so that we can make ksets dynamic, and cleans up one of the odd, undocumented assumption that the kset/kobject/ktype model has. This patch is based on a lot of help from Kay Sievers. Nasty bug in the block code was found by Dave Young <hidave.darkstar@gmail.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
debugfs: remove rmdir() non-empty complaint Hi, This patch kills the pointless debugfs rmdir() printk() when called on a non-empty directory. blktrace will sometimes have to call it a few times when forcefully ending a trace, which polutes the log with pointless warnings. Rationale: - It's more code to work-around this "problem" in the debugfs users, and you would have to add code to check for empty directories to do so (or assume that debugfs is using simple_ helpers, but that would be a layering violation). - Other rmdir() implementations don't complain about something this silly. Signed-off-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
remove "struct subsystem" as it is no longer needed We need to work on cleaning up the relationship between kobjects, ksets and ktypes. The removal of 'struct subsystem' is the first step of this, especially as it is not really needed at all. Thanks to Kay for fixing the bugs in this patch. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
debugfs: Remove misleading comments. Just mention which error will be returned if debugfs is disabled. Callers should be able to figure out themselves what they need to check. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
debugfs: implement symbolic links debugfs: implement symbolic links Implement a new function debugfs_create_symlink() which can be used to create symbolic links in debugfs. This function can be useful for people moving functionality from /proc to debugfs (e.g. the gcov-kernel patch). Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
DebugFS : file/directory removal fix Fix file and directory removal in debugfs. Add inotify support for file removal. The following scenario : create dir a create dir a/b cd a/b (some process goes in cwd a/b) rmdir a/b rmdir a fails due to the fact that "a" appears to be non empty. It is because the "b" dentry is not deleted from "a" and still in use. The same problem happens if "b" is a file. d_delete is nice enough to know when it needs to unhash and free the dentry if nothing else is using it or, if someone is using it, to remove it from the hash queues and wait for it to be deleted when it has no users. The nice side-effect of this fix is that it calls the file removal notification. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
DebugFS : more file/directory creation error handling Correct dentry count to handle creation errors. This patch puts a dput at the file creation instead of the file removal : lookup_one_len already returns a dentry with reference count of 1. Then, the dget() in simple_mknod increments it when the dentry is associated with a file. In a scenario where simple_create or simple_mkdir returns an error, this would lead to an unwanted increment of the reference counter, therefore making file removal impossible. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
DebugFS : file/directory creation error handling Fix error handling of file and directory creation in DebugFS. The error path should release the file system because no _remove will be called for this erroneous creation. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>