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* sysfs, kernfs: add sysfs_dirent->s_attr.sizeTejun Heo2013-11-293-7/+8
| | | | | | | | | | | | | | | | | sysfs sets the size of regular files unconditionally at PAGE_SIZE and takes the size of bin files from bin_attribute. The latter is a pretty bad interface which forces bin_attribute users to create a separate copy of bin_attribute for each instance of the file - e.g. pci resource files. Add sysfs_dirent->s_attr.size so that the size can be specified separately. This unifies inode init paths of ATTR and BIN_ATTR identical and allows for generic size handling for kernfs. Unfortunately, this grows the size of sysfs_dirent by sizeof(loff_t). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs, kernfs: introduce kernfs_opsTejun Heo2013-11-292-34/+115
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We're in the process of separating out core sysfs functionality into kernfs which will deal with sysfs_dirents directly. This patch introduces kernfs_ops which hosts methods kernfs users implement and updates fs/sysfs/file.c such that sysfs_kf_*() functions populate kernfs_ops and kernfs_file_*() functions call the matching entries from kernfs_ops. kernfs_ops contains the following groups of methods. * seq_show() - for kernfs files which use seq_file for reads. * read() - for direct read implementations. Used iff seq_show() is not implemented. * write() - for writes. * mmap() - for mmaps. Notes: * sysfs_elem_attr->ops is added so that kernfs_ops can be accessed from sysfs_dirent. kernfs_ops() helper is added to verify locking and access the field. * SYSFS_FLAG_HAS_(SEQ_SHOW|MMAP) added. sd->s_attr->ops is accessible only while holding active_ref and there are cases where we want to take different actions depending on which ops are implemented. These two flags cache whether the two ops are implemented for those. * kernfs_file_*() no longer test sysfs type but chooses different behaviors depending on which methods in kernfs_ops are implemented. The conversions are trivial except for the open path. As kernfs_file_open() now decides whether to allow read/write accesses depending on the kernfs_ops implemented, the presence of methods in kobjs and attribute_bin should be propagated to kernfs_ops. sysfs_add_file_mode_ns() is updated so that it propagates presence / absence of the callbacks through _empty, _ro, _wo, _rw kernfs_ops. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs, kernfs: move sysfs_open_file to include/linux/kernfs.hTejun Heo2013-11-291-11/+0
| | | | | | | | | | | sysfs_open_file will be used as the primary handle for kernfs methods. Move its definition from fs/sysfs/file.c to include/linux/kernfs.h and mark the public and private fields. This is pure relocation. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs, kernfs: prepare open, release, poll paths for kernfsTejun Heo2013-11-293-21/+10
| | | | | | | | | | | | | | We're in the process of separating out core sysfs functionality into kernfs which will deal with sysfs_dirents directly. This patch prepares the rest - open, release and poll. There isn't much to do. Just renaming is enough. As sysfs_file_operations and sysfs_bin_operations are identical now, use the same file_operations for both - kernfs_file_operations. This patch doesn't introduce any behavior changes. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs, kernfs: prepare mmap path for kernfsTejun Heo2013-11-291-30/+39
| | | | | | | | | | | | | | | | | | | We're in the process of separating out core sysfs functionality into kernfs which will deal with sysfs_dirents directly. This patch rearranges mmap path so that the kernfs and sysfs parts are separate. sysfs_kf_bin_mmap() which handles the interaction with bin_attribute mmap method is factored out of sysfs_bin_mmap(), which is renamed to kernfs_file_mmap(). All vma ops are renamed accordingly. sysfs_bin_mmap() is updated such that it can be used for both file types. This will eventually allow using the same file_operations for both file types, which is necessary to separate out kernfs. This patch doesn't introduce any behavior changes. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs, kernfs: prepare write path for kernfsTejun Heo2013-11-291-53/+50
| | | | | | | | | | | | | | | | | We're in the process of separating out core sysfs functionality into kernfs which will deal with sysfs_dirents directly. This patch rearranges write path so that the kernfs and sysfs parts are separate. kernfs_file_write() handles all boilerplate work including buffer management and locking and invokes sysfs_kf_write() or sysfs_kf_bin_write() depending on the file type which deals with the interaction with kobj store or bin_attribute write method. While this patch changes the order of some operations, it shouldn't change any visible behavior. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs, kernfs: prepare read path for kernfsTejun Heo2013-11-291-65/+126
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We're in the process of separating out core sysfs functionality into kernfs which will deal with sysfs_dirents directly. This patch rearranges read path so that the kernfs and sysfs parts are separate. * Regular file read path is refactored such that kernfs_seq_start/next/stop/show() handle all the boilerplate work including locking and updating event count for poll, while sysfs_kf_seq_show() deals with interaction with kobj show method. * Bin file read path is refactored such that kernfs_file_direct_read() handles all the boilerplate work including buffer management and locking, while sysfs_kf_bin_read() deals with interaction with bin_attribute read method. kernfs_file_read() is added. It invokes either the seq_file or direct read path depending on the file type. This will eventually allow using the same file_operations for both file types, which is necessary to separate out kernfs. While this patch changes the order of some operations, it shouldn't change any visible behavior. v2: Dropped unnecessary zeroing of @count from sysfs_kf_seq_show(). Add comments explaining single_open() behavior. Both suggested by Pavel. v3: seq_stop() is called even after seq_start() failed. kernfs_seq_start() updated so that it doesn't unlock sysfs_open_file->mutex on failure so that kernfs_seq_stop() doesn't try to unlock an already unlocked mutex. Reported by Fengguang. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs, kernfs: introduce kernfs_create_dir[_ns]()Tejun Heo2013-11-293-30/+36
| | | | | | | | | | | | | | | | | | | | | | | | | Introduce kernfs interface to manipulate a directory which takes and returns sysfs_dirents. create_dir() is renamed to kernfs_create_dir_ns() and its argumantes and return value are updated. create_dir() usages are replaced with kernfs_create_dir_ns() and sysfs_create_subdir() usages are replaced with kernfs_create_dir(). Dup warnings are handled explicitly by sysfs users of the kernfs interface. sysfs_enable_ns() is renamed to kernfs_enable_ns(). This patch doesn't introduce any behavior changes. v2: Dummy implementation for !CONFIG_SYSFS updated to return -ENOSYS. v3: kernfs_enable_ns() added. v4: Refreshed on top of "sysfs: drop kobj_ns_type handling, take #2" so that this patch removes sysfs_enable_ns(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs, kernfs: replace sysfs_dirent->s_dir.kobj and ->s_attr.[bin_]attr with ↵Tejun Heo2013-11-295-24/+21
| | | | | | | | | | | | | | | | | | | | | ->priv A directory sysfs_dirent points to the associated kobj. A regular or bin file points to the associated [bin_]attribute. This patch replaces sysfs_dirent->s_dir.kobj and ->s_attr.[bin_]attr with void * ->priv. This is to prepare for kernfs interface so that sysfs can specify the private data in the same way for directories and files. This lower debuggability but not by much - the whole thing was overlaid in a union anyway. If debuggability becomes an issue, we can later add ->priv accessors which explicitly check for the sysfs_dirent type and performs casting. This patch doesn't introduce any behavior difference. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge branch 'driver-core-linus' into driver-core-nextGreg Kroah-Hartman2013-11-271-2/+20
|\ | | | | | | | | | | | | We need those sysfs fixes in this branch to make testing, and future patches apply properly. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * Revert "sysfs: handle duplicate removal attempts in sysfs_remove_group()"Greg Kroah-Hartman2013-11-271-9/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 54d71145a4548330313ca664a4a009772fe8b7dd. The root cause of these "inverted" sysfs removals have now been found, so there is no need for this patch. Keep this functionality around so that this type of error doesn't show up in driver code again. Cc: Mika Westerberg <mika.westerberg@linux.intel.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * sysfs: use a separate locking class for open files depending on mmapTejun Heo2013-11-231-2/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following two commits implemented mmap support in the regular file path and merged bin file support into the regular path. 73d9714627ad ("sysfs: copy bin mmap support from fs/sysfs/bin.c to fs/sysfs/file.c") 3124eb1679b2 ("sysfs: merge regular and bin file handling") After the merge, the following commands trigger a spurious lockdep warning. "test-mmap-read" simply mmaps the file and dumps the content. $ cat /sys/block/sda/trace/act_mask $ test-mmap-read /sys/devices/pci0000\:00/0000\:00\:03.0/resource0 4096 ====================================================== [ INFO: possible circular locking dependency detected ] 3.12.0-work+ #378 Not tainted ------------------------------------------------------- test-mmap-read/567 is trying to acquire lock: (&of->mutex){+.+.+.}, at: [<ffffffff8120a8df>] sysfs_bin_mmap+0x4f/0x120 but task is already holding lock: (&mm->mmap_sem){++++++}, at: [<ffffffff8114b399>] vm_mmap_pgoff+0x49/0xa0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&mm->mmap_sem){++++++}: ... -> #2 (sr_mutex){+.+.+.}: ... -> #1 (&bdev->bd_mutex){+.+.+.}: ... -> #0 (&of->mutex){+.+.+.}: ... other info that might help us debug this: Chain exists of: &of->mutex --> sr_mutex --> &mm->mmap_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&mm->mmap_sem); lock(sr_mutex); lock(&mm->mmap_sem); lock(&of->mutex); *** DEADLOCK *** 1 lock held by test-mmap-read/567: #0: (&mm->mmap_sem){++++++}, at: [<ffffffff8114b399>] vm_mmap_pgoff+0x49/0xa0 stack backtrace: CPU: 3 PID: 567 Comm: test-mmap-read Not tainted 3.12.0-work+ #378 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 ffffffff81ed41a0 ffff880009441bc8 ffffffff81611ad2 ffffffff81eccb80 ffff880009441c08 ffffffff8160f215 ffff880009441c60 ffff880009c75208 0000000000000000 ffff880009c751e0 ffff880009c75208 ffff880009c74ac0 Call Trace: [<ffffffff81611ad2>] dump_stack+0x4e/0x7a [<ffffffff8160f215>] print_circular_bug+0x2b0/0x2bf [<ffffffff8109ca0a>] __lock_acquire+0x1a3a/0x1e60 [<ffffffff8109d6ba>] lock_acquire+0x9a/0x1d0 [<ffffffff81615547>] mutex_lock_nested+0x67/0x3f0 [<ffffffff8120a8df>] sysfs_bin_mmap+0x4f/0x120 [<ffffffff8115d363>] mmap_region+0x3b3/0x5b0 [<ffffffff8115d8ae>] do_mmap_pgoff+0x34e/0x3d0 [<ffffffff8114b3ba>] vm_mmap_pgoff+0x6a/0xa0 [<ffffffff8115be3e>] SyS_mmap_pgoff+0xbe/0x250 [<ffffffff81008282>] SyS_mmap+0x22/0x30 [<ffffffff8161a4d2>] system_call_fastpath+0x16/0x1b This happens because one file nests sr_mutex, which nests mm->mmap_sem under it, under of->mutex while mmap implementation naturally nests of->mutex under mm->mmap_sem. The warning is false positive as of->mutex is per open-file and the two paths belong to two different files. This warning didn't trigger before regular and bin file supports were merged because only bin file supported mmap and the other side of locking happened only on regular files which used equivalent but separate locking. It'd be best if we give separate locking classes per file but we can't easily do that. Let's differentiate on ->mmap() for now. Later we'll add explicit file operations struct and can add per-ops lockdep key there. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * sysfs: handle duplicate removal attempts in sysfs_remove_group()Mika Westerberg2013-11-231-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit bcdde7e221a8 (sysfs: make __sysfs_remove_dir() recursive) changed the behavior so that directory removals will be done recursively. This means that the sysfs group might already be removed if its parent directory has been removed. The current code outputs warnings similar to following log snippet when it detects that there is no group for the given kobject: WARNING: CPU: 0 PID: 4 at fs/sysfs/group.c:214 sysfs_remove_group+0xc6/0xd0() sysfs group ffffffff81c6f1e0 not found for kobject 'host7' Modules linked in: CPU: 0 PID: 4 Comm: kworker/0:0 Not tainted 3.12.0+ #13 Hardware name: /D33217CK, BIOS GKPPT10H.86A.0042.2013.0422.1439 04/22/2013 Workqueue: kacpi_hotplug acpi_hotplug_work_fn 0000000000000009 ffff8801002459b0 ffffffff817daab1 ffff8801002459f8 ffff8801002459e8 ffffffff810436b8 0000000000000000 ffffffff81c6f1e0 ffff88006d440358 ffff88006d440188 ffff88006e8b4c28 ffff880100245a48 Call Trace: [<ffffffff817daab1>] dump_stack+0x45/0x56 [<ffffffff810436b8>] warn_slowpath_common+0x78/0xa0 [<ffffffff81043727>] warn_slowpath_fmt+0x47/0x50 [<ffffffff811ad319>] ? sysfs_get_dirent_ns+0x49/0x70 [<ffffffff811ae526>] sysfs_remove_group+0xc6/0xd0 [<ffffffff81432f7e>] dpm_sysfs_remove+0x3e/0x50 [<ffffffff8142a0d0>] device_del+0x40/0x1b0 [<ffffffff8142a24d>] device_unregister+0xd/0x20 [<ffffffff8144131a>] scsi_remove_host+0xba/0x110 [<ffffffff8145f526>] ata_host_detach+0xc6/0x100 [<ffffffff8145f578>] ata_pci_remove_one+0x18/0x20 [<ffffffff812e8f48>] pci_device_remove+0x28/0x60 [<ffffffff8142d854>] __device_release_driver+0x64/0xd0 [<ffffffff8142d8de>] device_release_driver+0x1e/0x30 [<ffffffff8142d257>] bus_remove_device+0xf7/0x140 [<ffffffff8142a1b1>] device_del+0x121/0x1b0 [<ffffffff812e43d4>] pci_stop_bus_device+0x94/0xa0 [<ffffffff812e437b>] pci_stop_bus_device+0x3b/0xa0 [<ffffffff812e437b>] pci_stop_bus_device+0x3b/0xa0 [<ffffffff812e44dd>] pci_stop_and_remove_bus_device+0xd/0x20 [<ffffffff812fc743>] trim_stale_devices+0x73/0xe0 [<ffffffff812fc78b>] trim_stale_devices+0xbb/0xe0 [<ffffffff812fc78b>] trim_stale_devices+0xbb/0xe0 [<ffffffff812fcb6e>] acpiphp_check_bridge+0x7e/0xd0 [<ffffffff812fd90d>] hotplug_event+0xcd/0x160 [<ffffffff812fd9c5>] hotplug_event_work+0x25/0x60 [<ffffffff81316749>] acpi_hotplug_work_fn+0x17/0x22 [<ffffffff8105cf3a>] process_one_work+0x17a/0x430 [<ffffffff8105db29>] worker_thread+0x119/0x390 [<ffffffff8105da10>] ? manage_workers.isra.25+0x2a0/0x2a0 [<ffffffff81063a5d>] kthread+0xcd/0xf0 [<ffffffff81063990>] ? kthread_create_on_node+0x180/0x180 [<ffffffff817eb33c>] ret_from_fork+0x7c/0xb0 [<ffffffff81063990>] ? kthread_create_on_node+0x180/0x180 On this particular machine I see ~16 of these message during Thunderbolt hot-unplug. Fix this in similar way that was done for sysfs_remove_one() by checking if the parent directory has already been removed and bailing out early. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | sysfs, kernfs: introduce kernfs_setattr()Tejun Heo2013-11-273-11/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce kernfs setattr interface - kernfs_setattr(). sysfs_sd_setattr() is renamed to __kernfs_setattr() and kernfs_setattr() is a simple wrapper around it with sysfs_mutex locking. sysfs_chmod_file() is updated to get an explicit ref on kobj->sd and then invoke kernfs_setattr() so that it doesn't have to use internal interface. This patch doesn't introduce any behavior differences. v2: Dummy implementation for !CONFIG_SYSFS updated to return -ENOSYS. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | sysfs, kernfs: introduce kernfs_rename[_ns]()Tejun Heo2013-11-273-12/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | Introduce kernfs rename interface, krenfs_rename[_ns](). This is just rename of sysfs_rename(). No functional changes. Function comment is added to kernfs_rename_ns() and @new_parent_sd is renamed to @new_parent for consistency with other kernfs interfaces. v2: Dummy implementation for !CONFIG_SYSFS updated to return -ENOSYS. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | sysfs, kernfs: introduce kernfs_create_link()Tejun Heo2013-11-271-30/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Separate out kernfs symlink interface - kernfs_create_link() - which takes and returns sysfs_dirents, from sysfs_do_create_link_sd(). sysfs_do_create_link_sd() now just determines the parent and target sysfs_dirents and invokes the new interface and handles dup warning. This patch doesn't introduce behavior changes. v2: Dummy implementation for !CONFIG_SYSFS updated to return -ENOSYS. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | sysfs, kernfs: introduce kernfs_remove[_by_name[_ns]]()Tejun Heo2013-11-275-26/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce kernfs removal interfaces - kernfs_remove() and kernfs_remove_by_name[_ns](). These are just renames of sysfs_remove() and sysfs_hash_and_remove(). No functional changes. v2: Dummy kernfs_remove_by_name_ns() for !CONFIG_SYSFS updated to return -ENOSYS instead of 0. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | sysfs: make __sysfs_add_one() fail if the parent isn't a directoryTejun Heo2013-11-271-0/+3
| | | | | | | | | | | | | | | | | | | | | | Currently the kobject based interface guarantees that a parent sysfs_dirent is always a directory; however, the planned kernfs interface will be directly based on sysfs_dirents and the caller may specify non-directory node as the parent. Add an explicit check in __sysfs_add_one() so that such attempts fail with -EINVAL. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | sysfs: drop kobj_ns_type handling, take #2Tejun Heo2013-11-274-112/+55
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The way namespace tags are implemented in sysfs is more complicated than necessary. As each tag is a pointer value and required to be non-NULL under a namespace enabled parent, there's no need to record separately what type each tag is. If multiple namespace types are needed, which currently aren't, we can simply compare the tag to a set of allowed tags in the superblock assuming that the tags, being pointers, won't have the same value across multiple types. This patch rips out kobj_ns_type handling from sysfs. sysfs now has an enable switch to turn on namespace under a node. If enabled, all children are required to have non-NULL namespace tags and filtered against the super_block's tag. kobject namespace determination is now performed in lib/kobject.c::create_dir() making sysfs_read_ns_type() unnecessary. The sanity checks are also moved. create_dir() is restructured to ease such addition. This removes most kobject namespace knowledge from sysfs proper which will enable proper separation and layering of sysfs. This is the second try. The first one was cb26a311578e ("sysfs: drop kobj_ns_type handling") which tried to automatically enable namespace if there are children with non-NULL namespace tags; however, it was broken for symlinks as they should inherit the target's tag iff namespace is enabled in the parent. This led to namespace filtering enabled incorrectly for wireless net class devices through phy80211 symlinks and thus network configuration failure. a1212d278c05 ("Revert "sysfs: drop kobj_ns_type handling"") reverted the commit. This shouldn't introduce any behavior changes, for real. v2: Dummy implementation of sysfs_enable_ns() for !CONFIG_SYSFS was missing and caused build failure. Reported by kbuild test robot. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Kay Sievers <kay@vrfy.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Revert "sysfs: drop kobj_ns_type handling"Linus Torvalds2013-11-074-43/+121
| | | | | | | | | | | | | | This reverts commit cb26a311578e67769e92a39a0a63476533cb7e12. It mysteriously causes NetworkManager to not find the wireless device for me. As far as I can tell, Tejun *meant* for this commit to not make any semantic changes, but there clearly are some. So revert it, taking into account some of the calling convention changes that happened in this area in subsequent commits. Cc: Tejun Heo <tj@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysfs: rename sysfs_assoc_lock and explain what it's aboutTejun Heo2013-11-013-10/+30
| | | | | | | | | | | | | | | | | | | | | | sysfs_assoc_lock is an odd piece of locking. In general, whoever owns a kobject is responsible for synchronizing sysfs operations and sysfs proper assumes that, for example, removal won't race with any other operation; however, this doesn't work for symlinking because an entity performing symlink doesn't usually own the target kobject and thus has no control over its removal. sysfs_assoc_lock synchronizes symlink operations against kobj->sd disassociation so that symlink code doesn't end up dereferencing already freed sysfs_dirent by racing with removal of the target kobject. This is quite obscure and the generic name of the lock and lack of comments make it difficult to understand its role. Let's rename it to sysfs_symlink_target_lock and add comments explaining what's going on. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: use generic_file_llseek() for sysfs_file_operationsTejun Heo2013-11-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 13c589d5b0ac6 ("sysfs: use seq_file when reading regular files") converted regular sysfs files to use seq_file. The commit substituted generic_file_llseek() with seq_lseek() for llseek implementation. Before the change, all regular sysfs files were allowed to seek to any position in [0, PAGE_SIZE] as the file size is always PAGE_SIZE and generic_file_llseek() allows any seeking inside the range under file size; however, seq_lseek()'s behavior is different. It traverses the output by repeatedly invoking ->show() until it reaches the target offset or traversal indicates EOF. As seq_files are fully dynamic and may not end at all, it doesn't support seeking from the end (SEEK_END). Apparently, there are userland tools which uses SEEK_END to discover the buffer size to use and the switch to seq_lseek() disturbs them as SEEK_END fails with -EINVAL. The only benefits of using seq_lseek() instead of generic_file_llseek() are * Early failure. If traversing to certain file position should fail, seq_lseek() will report such failures on lseek(2) instead of the following read/write operations. * EOF detection. While SEEK_END is not supported, SEEK_SET/CUR + large offset can be used to detect eof - eof at the time of the seek anyway as the file size may change dynamically. Both aren't necessary for sysfs or prospect kernfs users. Revert to genefic_file_llseek() and preserve the original behavior. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Link: https://lkml.kernel.org/r/20131031114358.GA5551@osiris Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: return correct error code on unimplemented mmap()Vladimir Zapolskiy2013-10-301-1/+0
| | | | | | | | | | | Both POSIX.1-2008 and Linux Programmer's Manual have a dedicated return error code for a case, when a file doesn't support mmap(), it's ENODEV. This change replaces overloaded EINVAL with ENODEV in a situation described above for sysfs binary files. Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: separate out dup filename warning into a separate functionTejun Heo2013-10-292-11/+20
| | | | | | | | | | | Separate out sysfs_warn_dup() out of sysfs_add_one(). This will help separating out the core sysfs functionalities into kernfs so that it can be used by non-sysfs users too. This doesn't make any functional changes. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: move sysfs_hash_and_remove() to fs/sysfs/dir.cTejun Heo2013-10-293-30/+39
| | | | | | | | | | | Most removal related logic is implemented in fs/sysfs/dir.c. Move sysfs_hash_and_remove() to fs/sysfs/dir.c so that __sysfs_remove() doesn't have to be public. This is pure relocation. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: remove unused sysfs_get_dentry() prototypeTejun Heo2013-10-291-1/+0
| | | | | | | | sysfs_get_dentry() has been gone for years now. Remove the left-over prototype. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: honor bin_attr.attr.ignore_lockdepTejun Heo2013-10-291-1/+3
| | | | | | | | | | | | ignore_lockdep is currently honored only for regular files. There's no reason to ignore it for bin files. Update sysfs_ignore_lockdep() so that bin_attr.attr.ignore_lockdep works too. While this doesn't have any in-kernel user, this unifies the behaviors between regular and bin files and will help later changes. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: merge sysfs_elem_bin_attr into sysfs_elem_attrTejun Heo2013-10-293-12/+9
| | | | | | | | | | | | | | | | | | | | | 3124eb1679 ("sysfs: merge regular and bin file handling") folded bin file handling into regular file handling. Among other things, bin file now shares the same open path including sysfs_open_dirent association using sysfs_dirent->s_attr.open. This is buggy because ->s_bin_attr lives in the same union and doesn't have the field. This bug doesn't trigger because sysfs_elem_bin_attr doesn't have an active field at the conflicting position. It does have a field "buffers" but it isn't used anymore. This patch collapses sysfs_elem_bin_attr into sysfs_elem_attr so that the bin_attr is accessed through ->s_attr.bin_attr which lives with ->s_attr.attr in an anonymous union. The code paths already assume bin_attr contains attr as the first element, so this doesn't add any more assumptions while making it explicit that the two types are handled together. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: fix sysfs_write_file for bin fileMing Lei2013-10-251-3/+2
| | | | | | | | | | | | | | | | | | | | | Before patch(sysfs: prepare path write for unified regular / bin file handling), when size of bin file is zero, writting still can continue, but this patch changes the behaviour. The worse thing is that firmware loader is broken by this patch, and user space application can't write to firmware bin file any more because both firmware loader and drivers can't know at advance how large the firmware file is and have to set its initialized size as zero. This patch fixes the problem and keeps behaviour of writting to bin as before. Reported-by: Lothar Waßmann <LW@karo-electronics.de> Tested-by: Lothar Waßmann <LW@karo-electronics.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs/bin: Fix size handling overflow for bin_attributeBenjamin Herrenschmidt2013-10-141-1/+1
| | | | | | | | | | | | | | | | | While looking at the code, I noticed that bin_attribute read() and write() ops copy the inode size into an int for futher comparisons. Some bin_attributes can be fairly large. For example, pci creates some for BARs set to the BAR size and giant BARs are around the corner, so this is going to break something somewhere eventually. Let's use the right type. [adjust for seqfile conversions, only needed for bin_read() - gkh] Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: make sysfs_file_ops() follow ignore_lockdep flagTejun Heo2013-10-143-21/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 375b611e60 ("sysfs: remove sysfs_buffer->ops") introduced sysfs_file_ops() which determines the associated file operation of a given sysfs_dirent. As file ops access should be protected by an active reference, the new function includes a lockdep assertion on the sysfs_dirent; unfortunately, I forgot to take attr->ignore_lockdep flag into account and the lockdep assertion trips spuriously for files which opt out from active reference lockdep checking. # cat /sys/devices/pci0000:00/0000:00:01.2/usb1/authorized ------------[ cut here ]------------ WARNING: CPU: 1 PID: 540 at /work/os/work/fs/sysfs/file.c:79 sysfs_file_ops+0x4e/0x60() Modules linked in: CPU: 1 PID: 540 Comm: cat Not tainted 3.11.0-work+ #3 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 0000000000000009 ffff880016205c08 ffffffff81ca0131 0000000000000000 ffff880016205c40 ffffffff81096d0d ffff8800166cb898 ffff8800166f6f60 ffffffff8125a220 ffff880011ab1ec0 ffff88000aff0c78 ffff880016205c50 Call Trace: [<ffffffff81ca0131>] dump_stack+0x4e/0x82 [<ffffffff81096d0d>] warn_slowpath_common+0x7d/0xa0 [<ffffffff81096dea>] warn_slowpath_null+0x1a/0x20 [<ffffffff8125994e>] sysfs_file_ops+0x4e/0x60 [<ffffffff8125a274>] sysfs_open_file+0x54/0x300 [<ffffffff811df612>] do_dentry_open.isra.17+0x182/0x280 [<ffffffff811df820>] finish_open+0x30/0x40 [<ffffffff811f0623>] do_last+0x503/0xd90 [<ffffffff811f0f6b>] path_openat+0xbb/0x6d0 [<ffffffff811f23ba>] do_filp_open+0x3a/0x90 [<ffffffff811e09a9>] do_sys_open+0x129/0x220 [<ffffffff811e0abe>] SyS_open+0x1e/0x20 [<ffffffff81caf3c2>] system_call_fastpath+0x16/0x1b ---[ end trace aa48096b111dafdb ]--- Rename fs/sysfs/dir.c::ignore_lockdep() to sysfs_ignore_lockdep() and move it to fs/sysfs/sysfs.h and make sysfs_file_ops() skip lockdep assertion if sysfs_ignore_lockdep() is true. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: merge regular and bin file handlingTejun Heo2013-10-056-501/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the previous changes, sysfs regular file code is ready to handle bin files too. This patch makes bin files share the regular file path. * sysfs_create/remove_bin_file() are moved to fs/sysfs/file.c. * sysfs_init_inode() is updated to use the new sysfs_bin_operations instead of bin_fops for bin files. * fs/sysfs/bin.c and the related pieces are removed. This patch shouldn't introduce any behavior difference to bin file accesses. Overall, this unification reduces the amount of duplicate logic, makes behaviors more consistent and paves the road for building simpler and more versatile interface which will allow other subsystems to make use of sysfs for their pseudo filesystems. v2: Stale fs/sysfs/bin.c reference dropped from Documentation/DocBook/filesystems.tmpl. Reported by kbuild test robot. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Kay Sievers <kay@vrfy.org> Cc: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: prepare open path for unified regular / bin file handlingTejun Heo2013-10-051-25/+33
| | | | | | | | | | | | | sysfs bin file handling will be merged into the regular file support. This patch prepares the open path. This patch updates sysfs_open_file() such that it can handle both regular and bin files. This is a preparation and the new bin file path isn't used yet. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: copy bin mmap support from fs/sysfs/bin.c to fs/sysfs/file.cTejun Heo2013-10-053-1/+249
| | | | | | | | | | | | | | | | | | | | | | | | sysfs bin file handling will be merged into the regular file support. This patch copies mmap support from bin so that fs/sysfs/file.c can handle mmapping bin files. The code is copied mostly verbatim with the following updates. * ->mmapped and ->vm_ops are added to sysfs_open_file and bin_buffer references are replaced with sysfs_open_file ones. * Symbols are prefixed with sysfs_. * sysfs_unmap_bin_file() grabs sysfs_open_dirent and traverses ->files. Invocation of this function is added to sysfs_addrm_finish(). * sysfs_bin_mmap() is added to sysfs_bin_operations. This is a preparation and the new mmap path isn't used yet. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: add sysfs_bin_read()Tejun Heo2013-10-051-0/+65
| | | | | | | | | | | | | | | sysfs bin file handling will be merged into the regular file support. This patch prepares the read path. Copy fs/sysfs/bin.c::read() to fs/sysfs/file.c and make it use sysfs_open_file instead of bin_buffer. The function is identical copy except for the use of sysfs_open_file. The new function is added to sysfs_bin_operations. This isn't used yet but will eventually replace fs/sysfs/bin.c. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: prepare path write for unified regular / bin file handlingTejun Heo2013-10-052-6/+35
| | | | | | | | | | | | | | | | | sysfs bin file handling will be merged into the regular file support. This patch prepares the write path. bin file write is almost identical to regular file write except that the write length is capped by the inode size and @off is passed to the write method. This patch adds bin file handling to sysfs_write_file() so that it can handle both regular and bin files. A new file_operations struct sysfs_bin_operations is added, which currently only hosts sysfs_write_file() and generic_file_llseek(). This isn't used yet but will eventually replace fs/sysfs/bin.c. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: collapse fs/sysfs/bin.c::fill_read() into read()Tejun Heo2013-10-051-21/+15
| | | | | | | | | read() is simple enough and fill_read() being in a separate function doesn't add anything. Let's collapse it into read(). This will make merging bin file handling with regular file. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: skip bin_buffer->buffer while readingTejun Heo2013-10-051-13/+8
| | | | | | | | | | | | After b31ca3f5dfc ("sysfs: fix deadlock"), bin read() first writes data to bb->buffer and bounces it to a transient kernel buffer which is then copied out to userland. The double bouncing doesn't add anything. Let's just use the transient buffer directly. While at it, rename @temp to @buf for clarity. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: use seq_file when reading regular filesTejun Heo2013-10-051-91/+73
| | | | | | | | | | | | | | | | | | | | | | | | | | sysfs read path implements its own buffering scheme between userland and kernel callbacks, which essentially is a degenerate duplicate of seq_file. This patch replaces the custom read buffering implementation in sysfs with seq_file. While the amount of code reduction is small, this reduces low level hairiness and enables future development of a new versatile API based on seq_file so that sysfs features can be shared with other subsystems. As write path was already converted to not use sysfs_open_file->page, this patch makes ->page and ->count unused and removes them. Userland behavior remains the same except for some extreme corner cases - e.g. sysfs will now regenerate the content each time a file is read after a non-contiguous seek whereas the original code would keep using the same content. While this is a userland visible behavior change, it is extremely unlikely to be noticeable and brings sysfs behavior closer to that of procfs. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Kay Sievers <kay@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: use transient write bufferTejun Heo2013-10-051-62/+52
| | | | | | | | | | | | | | | | | | | | | | | | There isn't much to be gained by keeping around kernel buffer while a file is open especially as the read path planned to be converted to use seq_file and won't use the buffer. This patch makes sysfs_write_file() use per-write transient buffer instead of sysfs_open_file->page. This simplifies the write path, enables removing sysfs_open_file->page once read path is updated and will help merging bin file write path which already requires the use of a transient buffer due to a locking order issue. As the function comments of flush_write_buffer() and sysfs_write_buffer() are being updated anyway, reformat them so that they're more conventional. v2: Use min_t() instead of min() in sysfs_write_file() to avoid build warning on arm. Reported by build test robot. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: add sysfs_open_file->sd and ->fileTejun Heo2013-10-051-11/+12
| | | | | | | | | | | | | | | | sysfs will be converted to use seq_file for read path, which will make it difficult to pass around multiple pointers directly. This patch adds sysfs_open_file->sd and ->file so that we can reach all the necessary data structures from sysfs_open_file. flush_write_buffer() is updated to drop @dentry which was used to discover the sysfs_dirent as it's now available through sysfs_open_file->sd. This patch doesn't cause any behavior difference. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: rename sysfs_buffer to sysfs_open_fileTejun Heo2013-10-051-64/+63
| | | | | | | | | | | sysfs read path will be converted to use seq_file which will handle buffering making sysfs_buffer a misnomer. Rename sysfs_buffer to sysfs_open_file, and sysfs_open_dirent->buffers to ->files. This path is pure rename. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: add sysfs_open_file_mutexTejun Heo2013-10-051-6/+12
| | | | | | | | | | | | | Add a separate mutex to protect sysfs_open_dirent->buffers list. This will allow performing sleepable operations while traversing sysfs_buffers, which will be renamed to sysfs_open_file. Note that currently sysfs_open_dirent->buffers list isn't being used for anything and this patch doesn't make any functional difference. It will be used to merge regular and bin file supports. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: remove sysfs_buffer->opsTejun Heo2013-10-051-12/+21
| | | | | | | | | | | | Currently, sysfs_ops is fetched during sysfs_open_file() and cached in sysfs_buffer->ops to be used while the file is open. This patch removes the caching and makes each operation directly fetch sysfs_ops. This patch doesn't introduce any behavior difference and is to prepare for merging regular and bin file supports. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: remove sysfs_buffer->needs_read_fillTejun Heo2013-10-051-12/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | ->needs_read_fill is used to implement the following behaviors. 1. Ensure buffer filling on the first read. 2. Force buffer filling after a write. 3. Force buffer filling after a successful poll. However, #2 and #3 don't really work as sysfs doesn't reset file position. While the read buffer would be refilled, the next read would continue from the position after the last read or write, requiring an explicit seek to the start for it to be useful, which makes ->needs_read_fill superflous as read buffer is always refilled if f_pos == 0. Update sysfs_read_file() to test buffer->page for #1 instead and remove ->needs_read_fill. While this changes behavior in extreme corner cases - e.g. re-reading a sysfs file after seeking to non-zero position after a write or poll, it's highly unlikely to lead to actual breakage. This change is to prepare for using seq_file in the read path. While at it, reformat a comment in fill_write_buffer(). Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Kay Sievers <kay@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: remove unused sysfs_buffer->posTejun Heo2013-10-051-1/+0
| | | | | Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: introduce [__]sysfs_remove()Tejun Heo2013-10-034-28/+29
| | | | | | | | | | | | | Given a sysfs_dirent, there is no reason to have multiple versions of removal functions. A function which removes the specified sysfs_dirent and its descendants is enough. This patch intorduces [__}sysfs_remove() which replaces all internal variations of removal functions. This will be the only removal function in the planned new sysfs_dirent based interface. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: make __sysfs_remove_dir() recursiveTejun Heo2013-10-031-11/+64
| | | | | | | | | | | | | | | | | | | | | Currently, sysfs directory removal is inconsistent in that it would remove any files directly under it but wouldn't recurse into directories. Thanks to group subdirectories, this doesn't even match with kobject boundaries. sysfs is in the process of being separated out so that it can be used by multiple subsystems and we want to have a consistent behavior - either removal of a sysfs_dirent should remove every descendant entries or none instead of something inbetween. This patch implements proper recursive removal in __sysfs_remove_dir(). The function now walks its subtree in a post-order walk to remove all descendants. This is a behavior change but kobject / driver layer, which currently is the only consumer, has already been updated to handle duplicate removal attempts, so nothing should be broken after this change. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kobject: grab an extra reference on kobject->sd to allow duplicate deletesTejun Heo2013-10-031-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | sysfs currently has a rather weird behavior regarding removals. A directory removal would delete all files directly under it but wouldn't recurse into subdirectories, which, while a bit inconsistent, seems to make sense at the first glance as each directory is supposedly associated with a kobject and each kobject can take care of the directory deletion; however, this doesn't really hold as we have groups which can be directories without a kobject associated with it and require explicit deletions. We're in the process of separating out sysfs from kboject / driver core and want a consistent behavior. A removal should delete either only the specified node or everything under it. I think it is helpful to support recursive atomic removal and later patches will implement it. Such change means that a sysfs_dirent associated with kobject may be deleted before the kobject itself is removed if one of its ancestor gets removed before it. As sysfs_remove_dir() puts the base ref, we may end up with dangling pointer on descendants. This can be solved by holding an extra reference on the sd from kobject. Acquire an extra reference on the associated sysfs_dirent on directory creation and put it after removal. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: remove sysfs_addrm_cxt->parent_sdTejun Heo2013-10-035-36/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | sysfs_addrm_start/finish() enclose sysfs_dirent additions and deletions and sysfs_addrm_cxt is used to record information necessary to finish the operations. Currently, sysfs_addrm_start() takes @parent_sd, records it in sysfs_addrm_cxt, and assumes that all operations in the block are performed under that @parent_sd. This assumption has been fine until now but we want to make some operations behave recursively and, while having @parent_sd recorded in sysfs_addrm_cxt doesn't necessarily prevents that, it becomes confusing. This patch removes sysfs_addrm_cxt->parent_sd and makes sysfs_add_one() take an explicit @parent_sd parameter. Note that sysfs_remove_one() doesn't need the extra argument as its parent is always known from the target @sd. While at it, add __acquires/releases() notations to sysfs_addrm_start/finish() respectively. This patch doesn't make any functional difference. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-06 19:44:16 +0000