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* sysfs: Comment sysfs directory tagging logicSerge E. Hallyn2010-05-21
| | | | | | | | | | | | | | | | | | Add some in-line comments to explain the new infrastructure, which was introduced to support sysfs directory tagging with namespaces. I think an overall description someplace might be good too, but it didn't really seem to fit into Documentation/filesystems/sysfs.txt, which appears more geared toward users, rather than maintainers, of sysfs. (Tejun, please let me know if I can make anything clearer or failed altogether to comment something that should be commented.) Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Add support for tagged directories with untagged members.Eric W. Biederman2010-05-21
| | | | | | | | | | | | I had hopped to avoid this but the bonding driver adds a file to /sys/class/net/ and the easiest way to handle that file is to make it untagged and to register it only once. So relax the rules on tagged directories, and make bonding work. Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Implement sysfs tagged directory support.Eric W. Biederman2010-05-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The problem. When implementing a network namespace I need to be able to have multiple network devices with the same name. Currently this is a problem for /sys/class/net/*, /sys/devices/virtual/net/*, and potentially a few other directories of the form /sys/ ... /net/*. What this patch does is to add an additional tag field to the sysfs dirent structure. For directories that should show different contents depending on the context such as /sys/class/net/, and /sys/devices/virtual/net/ this tag field is used to specify the context in which those directories should be visible. Effectively this is the same as creating multiple distinct directories with the same name but internally to sysfs the result is nicer. I am calling the concept of a single directory that looks like multiple directories all at the same path in the filesystem tagged directories. For the networking namespace the set of directories whose contents I need to filter with tags can depend on the presence or absence of hotplug hardware or which modules are currently loaded. Which means I need a simple race free way to setup those directories as tagged. To achieve a reace free design all tagged directories are created and managed by sysfs itself. Users of this interface: - define a type in the sysfs_tag_type enumeration. - call sysfs_register_ns_types with the type and it's operations - sysfs_exit_ns when an individual tag is no longer valid - Implement mount_ns() which returns the ns of the calling process so we can attach it to a sysfs superblock. - Implement ktype.namespace() which returns the ns of a syfs kobject. Everything else is left up to sysfs and the driver layer. For the network namespace mount_ns and namespace() are essentially one line functions, and look to remain that. Tags are currently represented a const void * pointers as that is both generic, prevides enough information for equality comparisons, and is trivial to create for current users, as it is just the existing namespace pointer. The work needed in sysfs is more extensive. At each directory or symlink creating I need to check if the directory it is being created in is a tagged directory and if so generate the appropriate tag to place on the sysfs_dirent. Likewise at each symlink or directory removal I need to check if the sysfs directory it is being removed from is a tagged directory and if so figure out which tag goes along with the name I am deleting. Currently only directories which hold kobjects, and symlinks are supported. There is not enough information in the current file attribute interfaces to give us anything to discriminate on which makes it useless, and there are no potential users which makes it an uninteresting problem to solve. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Benjamin Thery <benjamin.thery@bull.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Pass super_block to sysfs_get_inodeEric W. Biederman2010-03-07
| | | | | | | | | | | | Currently sysfs_get_inode magically returns an inode on sysfs_sb. Make the super_block parameter explicit and the code becomes clearer. Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Only take active references on attributes.Eric W. Biederman2010-03-07
| | | | | | | | | | | | | | | | If we exclude directories and symlinks from the set of sysfs dirents where we need active references we are left with sysfs attributes (binary or not). - Tweak sysfs_deactivate to only do something on attributes - Move lockdep initialization into sysfs_file_add_mode to limit it to just attributes. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: WANG Cong <xiyou.wangcong@gmail.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Remove sysfs_get/put_active_twoEric W. Biederman2010-03-07
| | | | | | | | | | | | | | | | It turns out that holding an active reference on a directory is pointless. The purpose of the active references are to allows us to block when removing sysfs entries that have custom methods so we don't remove modules while running modular code and to keep those custom methods from accessing data structures after the files have been removed. Further sysfs_remove_dir remove all elements in the directory before removing the directory itself, so there is no chance we will remove a directory with active children. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Cache the last sysfs_dirent to improve readdir scalability v2Eric W. Biederman2010-03-07
| | | | | | | | | | | | | | | | | | | | | | | | When sysfs_readdir stops short we now cache the next sysfs_dirent to return to user space in filp->private_data. There is no impact on the rest of sysfs by doing this and in the common case it allows us to pick up exactly where we left off with no seeking. Additionally I drop and regrab the sysfs_mutex around filldir to avoid a page fault abritrarily increasing the hold time on the sysfs_mutex. v2: Returned to using INT_MAX as the EOF condition. seekdir is ambiguous unless all directory entries have a unique f_pos value. Fixes http://bugzilla.kernel.org/show_bug.cgi?id=14949 Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Add lockdep annotations for the sysfs active referenceEric W. Biederman2010-01-04
| | | | | | | | | | | | | | | | | | | | | | | Holding locks over device_del -> kobject_del -> sysfs_deactivate can cause deadlocks if those same locks are grabbed in sysfs show or store methods. The I model s_active count + completion as a sleeping read/write lock. I describe to lockdep sysfs_get_active as a read_trylock, sysfs_put_active as a read_unlock, and sysfs_deactivate as a write_lock and write_unlock pair. This seems to capture the essence for purposes of finding deadlocks, and in my testing gives finds real issues and ignores non-issues. This brings us back to holding locks over kobject_del is a problem that ideally we should find a way of addressing, but at least lockdep can tell us about the problems instead of requiring developers to debug rare strange system deadlocks, that happen when sysfs files are removed while being written to. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysfs: Factor out sysfs_rename from sysfs_rename_dir and sysfs_move_dirEric W. Biederman2009-12-11
| | | | | | | | | | | | | These two functions do 90% of the same work and it doesn't significantly obfuscate the function to allow both the parent dir and the name to change at the same time. So merge them together to simplify maintenance, and increase testing. Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Propagate renames to the vfs on demandEric W. Biederman2009-12-11
| | | | | | | | | | | | | | | | | | By teaching sysfs_revalidate to hide a dentry for a sysfs_dirent if the sysfs_dirent has been renamed, and by teaching sysfs_lookup to return the original dentry if the sysfs dirent has been renamed. I can show the results of renames correctly without having to update the dcache during the directory rename. This massively simplifies the rename logic allowing a lot of weird sysfs special cases to be removed along with a lot of now unnecesary helper code. Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Gut sysfs_addrm_start and sysfs_addrm_finishEric W. Biederman2009-12-11
| | | | | | | | | | | | | With lazy inode updates and dentry operations bringing everything into sync on demand there is no longer any need to immediately update the vfs or grab i_mutex to protect those updates as we make changes to sysfs. Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Implement sysfs_getattr & sysfs_permissionEric W. Biederman2009-12-11
| | | | | | | | | | | | | | | | | With the implementation of sysfs_getattr and sysfs_permission sysfs becomes able to lazily propogate inode attribute changes from the sysfs_dirents to the vfs inodes. This paves the way for deleting significant chunks of now unnecessary code. While doing this we did not reference sysfs_setattr from sysfs_symlink_inode_operations so I added along with sysfs_getattr and sysfs_permission. Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Update s_iattr on link and unlink.Eric W. Biederman2009-12-11
| | | | | | | | | | | | Currently sysfs updates the timestamps on the vfs directory inode when we create or remove a directory entry but doesn't update the cached copy on the sysfs_dirent, fix that oversight. Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Use dentry_ops instead of directly playing with the dcacheEric W. Biederman2009-12-11
| | | | | | | | | | | | | Calling d_drop unconditionally when a sysfs_dirent is deleted has the potential to leak mounts, so instead implement dentry delete and revalidate operations that cause sysfs dentries to be removed at the appropriate time. Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Rename sysfs_d_iput to sysfs_dentry_iputEric W. Biederman2009-12-11
| | | | | | | | | | | | Using dentry instead of d in the function name is what several other filesystems are doing and it seems to be a more readable convention. Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Don't leak secdata when a sysfs_dirent is freed.Eric W. Biederman2009-11-04
| | | | | | | | | | | | While refreshing my sysfs patches I noticed a leak in the secdata implementation. We don't free the secdata when we free the sysfs dirent. This is a bug in 2.6.32-rc5 that we really should close. Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
* sysfs: Allow sysfs_move_dir(..., NULL) again.Cornelia Huck2009-10-14
| | | | | | | | | | | As device_move() and kobject_move() both handle a NULL destination, sysfs_move_dir() should do this as well (again) and fall back to sysfs_root in that case. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Cc: Phil Carmody <ext-phil.2.carmody@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Add labeling support for sysfsDavid P. Quigley2009-09-09
| | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a setxattr handler to the file, directory, and symlink inode_operations structures for sysfs. The patch uses hooks introduced in the previous patch to handle the getting and setting of security information for the sysfs inodes. As was suggested by Eric Biederman the struct iattr in the sysfs_dirent structure has been replaced by a structure which contains the iattr, secdata and secdata length to allow the changes to persist in the event that the inode representing the sysfs_dirent is evicted. Because sysfs only stores this information when a change is made all the optional data is moved into one dynamically allocated field. This patch addresses an issue where SELinux was denying virtd access to the PCI configuration entries in sysfs. The lack of setxattr handlers for sysfs required that a single label be assigned to all entries in sysfs. Granting virtd access to every entry in sysfs is not an acceptable solution so fine grained labeling of sysfs is required such that individual entries can be labeled appropriately. [sds: Fixed compile-time warnings, coding style, and setting of inode security init flags.] Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov> Signed-off-by: Stephen D. Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
* sysfs: fix hardlink count on device_movePeter Oberparleiter2009-07-28
| | | | | | | | | | | | | | | | | | Update directory hardlink count when moving kobjects to a new parent. Fixes the following problem which occurs when several devices are moved to the same parent and then unregistered: > ls -laF /sys/devices/css0/defunct/ > total 0 > drwxr-xr-x 4294967295 root root 0 2009-07-14 17:02 ./ > drwxr-xr-x 114 root root 0 2009-07-14 17:02 ../ > drwxr-xr-x 2 root root 0 2009-07-14 17:01 power/ > -rw-r--r-- 1 root root 4096 2009-07-14 17:01 uevent Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Merge branch 'for-linus' of ↵Linus Torvalds2009-03-27
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (37 commits) fs: avoid I_NEW inodes Merge code for single and multiple-instance mounts Remove get_init_pts_sb() Move common mknod_ptmx() calls into caller Parse mount options just once and copy them to super block Unroll essentials of do_remount_sb() into devpts vfs: simple_set_mnt() should return void fs: move bdev code out of buffer.c constify dentry_operations: rest constify dentry_operations: configfs constify dentry_operations: sysfs constify dentry_operations: JFS constify dentry_operations: OCFS2 constify dentry_operations: GFS2 constify dentry_operations: FAT constify dentry_operations: FUSE constify dentry_operations: procfs constify dentry_operations: ecryptfs constify dentry_operations: CIFS constify dentry_operations: AFS ...
| * constify dentry_operations: sysfsAl Viro2009-03-27
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | sysfs: don't block indefinitely for unmapped files.Eric W. Biederman2009-03-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Modify sysfs bin files so that we can remove the bin file while they are still mapped. When the kobject is removed we unmap the bin file and arrange for future accesses to the mapping to receive SIGBUS. Implementing this prevents a nasty DOS when pci devices are hot plugged and unplugged. Where if any of their resources were mmaped the kernel could not free up their pci resources or release their pci data structures. [akpm@linux-foundation.org: remove unused var] Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* | sysfs: sysfs_add_one WARNs with full path to duplicate filenameAlex Chiang2009-03-24
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sysfs: sysfs_add_one WARNs with full path to duplicate filename As a debugging aid, it can be useful to know the full path to a duplicate file being created in sysfs. We now will display warnings such as: sysfs: cannot create duplicate filename '/foo' when attempting to create multiple files named 'foo' in the sysfs root, or: sysfs: cannot create duplicate filename '/bus/pci/slots/5/foo' when attempting to create multiple files named 'foo' under a given directory in sysfs. The path displayed is always a relative path to sysfs_root. The leading '/' in the path name refers to the sysfs_root mount point, and should not be confused with the "real" '/'. Thanks to Alex Williamson for essentially writing sysfs_pathname. Cc: Alex Williamson <alex.williamson@hp.com> Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] fix ->llseek for more directoriesChristoph Hellwig2008-10-23
| | | | | | | With this patch all directory fops instances that have a readdir that doesn't take the BKL are switched to generic_file_llseek. Signed-off-by: Christoph Hellwig <hch@lst.de>
* kobject: Cleanup kobject_rename and !CONFIG_SYSFSEric W. Biederman2008-10-16
| | | | | | | | | | | | It finally dawned on me what the clean fix to sysfs_rename_dir calling kobject_set_name is. Move the work into kobject_rename where it belongs. The callers serialize us anyway so this is safe. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: use ilookup5() instead of ilookup5_nowait()Tejun Heo2008-10-16
| | | | | | | | | | | | | | | As inode creation is protected by sysfs_mutex, ilookup5_nowait() always either fails to find at all or finds one which is fully initialized, so using ilookup5_nowait() or ilookup5() doesn't make any difference. Switch to ilookup5() as it's planned to be removed. This change also makes lookup return value handling a bit simpler. This change was suggested by Al Viro. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Al Viro <viro@hera.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Support sysfs_notify from atomic context with new sysfs_notify_direntNeil Brown2008-10-16
| | | | | | | | | | | | | | | | | | | | | | | | | Support sysfs_notify from atomic context with new sysfs_notify_dirent sysfs_notify currently takes sysfs_mutex. This means that it cannot be called in atomic context. sysfs_mutex is sometimes held over a malloc (sysfs_rename_dir) so it can block on low memory. In md I want to be able to notify on a sysfs attribute from atomic context, and I don't want to block on low memory because I could be in the writeout path for freeing memory. So: - export the "sysfs_dirent" structure along with sysfs_get, sysfs_put and sysfs_get_dirent so I can get the sysfs_dirent that I want to notify on and hold it in an md structure. - split sysfs_notify_dirent out of sysfs_notify so the sysfs_dirent can be notified on with no blocking (just a spinlock). Signed-off-by: Neil Brown <neilb@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Use WARN() in fs/sysfsArjan van de Ven2008-07-26
| | | | | | | | | | Use WARN() instead of a printk+WARN_ON() pair; this way the message becomes part of the warning section for better reporting/collection. Also, with this, one fo the if() sections collapses entirely into the WARN(). Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* driver core: Suppress sysfs warnings for device_rename().Cornelia Huck2008-07-22
| | | | | | | | | | | | | driver core: Suppress sysfs warnings for device_rename(). Renaming network devices to an already existing name is not something we want sysfs to print a scary warning for, since the callers can deal with this correctly. So let's introduce sysfs_create_link_nowarn() which gets rid of the common warning. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: remove error messages for -EEXIST caseStephen Hemminger2008-05-15
| | | | | | | | | | | | | | It is possible that the entry in sysfs already exists, one case of this is when a network device is renamed to bonding_masters. Anyway, in this case the proper error path is for device_rename to return an error code, not to generate bogus backtrace and errors. Also, to avoid possible races, the create link should be done before the remove link. This makes a device rename atomic operation like other renames. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: David S. Miller <davem@davemloft.net>
* SYSFS: Explicitly include required header file slab.h.Robert P. J. Day2008-04-19
| | | | | | | | | | | After an experimental deletion of the unnecessary inclusion of <linux/slab.h> from the header file <linux/percpu.h>, the following files under fs/sysfs were exposed as needing to explicitly include <linux/slab.h>. Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Fix a copy-n-paste typo in commentJean Delvare2008-01-24
| | | | | | Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: fix bugs in sysfs_rename/move_dir()Tejun Heo2008-01-16
| | | | | | | | | | | | sysfs_rename/move_dir() have the following bugs. - On dentry lookup failure, kfree() is called on ERR_PTR() value. - sysfs_move_dir() has an extra dput() on success path. Fix them. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysfs: make sysfs_lookup() return ERR_PTR(-ENOENT) on failed lookupTejun Heo2008-01-16
| | | | | | | | | | | | | | sysfs tries to keep dcache a strict subset of sysfs_dirent tree by shooting down dentries when a node is removed, that is, no negative dentry for sysfs. However, the lookup function returned NULL and thus created negative dentries when the target node didn't exist. Make sysfs_lookup() return ERR_PTR(-ENOENT) on lookup failure. This fixes the NULL dereference bug in sysfs_get_dentry() discovered by bluetooth rfcomm device moving around. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysfs: make sysfs_{get,put}_active() staticAdrian Bunk2007-10-31
| | | | | | | | sysfs_{get,put}_active() can now become static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* spin_lock_unlocked cleanupsRoel Kluin2007-10-17
| | | | | | | | | Replace some SPIN_LOCK_UNLOCKED with DEFINE_SPINLOCK Signed-off-by: Roel Kluin <12o3l@tiscali.nl> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* partially fix up the lookup_one_noperm messChristoph Hellwig2007-10-17
| | | | | | | | | | | | | | | | | | | | | | | Try to fix the mess created by sysfs braindamage. - refactor code internal to fs/namei.c a little to avoid too much duplication: o __lookup_hash_kern is renamed back to __lookup_hash o the old __lookup_hash goes away, permission checks moves to the two callers o useless inline qualifiers on above functions go away - lookup_one_len_kern loses it's last argument and is renamed to lookup_one_noperm to make it's useage a little more clear - added kerneldoc comments to describe lookup_one_len aswell as lookup_one_noperm and make it very clear that no one should use the latter ever. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Josef 'Jeff' Sipek <jsipek@cs.sunysb.edu> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysfs: add copyrightsTejun Heo2007-10-12
| | | | | | | | | Sysfs has gone through considerable amount of reimplementation. Add copyrights. Any objections? :-) Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: move sysfs file poll implementation to sysfs_open_direntTejun Heo2007-10-12
| | | | | | | | | | | | | | | | | | | | | | | | | Sysfs file poll implementation is scattered over sysfs and kobject. Event numbering is done in sysfs_dirent but wait itself is done on kobject. This not only unecessarily bloats both kobject and sysfs_dirent but is also buggy - if a sysfs_dirent is removed while there still are pollers, the associaton betwen the kobject and sysfs_dirent breaks and kobject may be freed with the pollers still sleeping on it. This patch moves whole poll implementation into sysfs_open_dirent. Each time a sysfs_open_dirent is created, event number restarts from 1 and pollers sleep on sysfs_open_dirent. As event sequence number is meaningless without any open file and pollers should have open file and thus sysfs_open_dirent, this ephemeral event counting works and is a saner implementation. This patch fixes the dnagling sleepers bug and reduces the sizes of kobject and sysfs_dirent by one pointer. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: move sysfs_dirent->s_children into sysfs_dirent->s_dirTejun Heo2007-10-12
| | | | | | | | | | | Children list head is only meaninful for directory nodes. Move it into s_dir. This doesn't save any space currently but it will with further changes. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: open code sysfs_attach_dentry()Tejun Heo2007-10-12
| | | | | | | | | | sysfs_attach_dentry() now has only one caller and isn't doing much other than obfuscating the code. Open code and kill it. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: make s_elem an anonymous unionTejun Heo2007-10-12
| | | | | | | | | | Make s_elem an anonymous union. Prefixing with s_elem makes things needlessly longer without any advantage. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: fix comments of sysfs_add/remove_one()Tejun Heo2007-10-12
| | | | | | | | | | sysfs_add/remove_one() now link and unlink the target dirent into and from the children list. Update comments accordingly. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: spit a warning to users when they try to create a duplicate sysfs fileGreg Kroah-Hartman2007-10-12
| | | | | | | | | We want to let people know when we create a duplicate sysfs file, as they need to fix up their code. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Rewrite sysfs_move_dir in terms of sysfs direntsEric W. Biederman2007-10-12
| | | | | | | | | | | | | | This patch rewrites sysfs_move_dir to perform it's checks as much as possible on the underlying sysfs_dirents instead of the contents of the dcache, making sysfs_move_dir more like the rest of the sysfs directory modification code. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Rewrite rename in terms of sysfs direntsEric W. Biederman2007-10-12
| | | | | | | | | | | | | | | | This patch rewrites sysfs_rename_dir to perform it's checks as much as possible on the underlying sysfs_dirents instead of the contents of the dcache. It turns out that this version is a little simpler, and a little more like the rest of the sysfs directory modification code. tj: fixed double locking of sysfs_mutex Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Remove s_dentryEric W. Biederman2007-10-12
| | | | | | | | | | | | | The only uses of s_dentry left are the code that maintains s_dentry and trivial users that don't actually need it. So this patch removes the s_dentry maintenance code and restructures the trivial uses to use something else. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: simply sysfs_get_dentryTejun Heo2007-10-12
| | | | | | | | | | | | | Now that we know the sysfs tree structure cannot change under us and sysfs shadow support is dropped, sysfs_get_dentry() can be simplified greatly. It can just look up from the root and there's no need to retry on failure. Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Introduce sysfs_rename_mutexEric W. Biederman2007-10-12
| | | | | | | | | | | | | | | | | | | | | Looking carefully at the rename code we have a subtle dependency that the structure of sysfs not change while we are performing a rename. If the parent directory of the object we are renaming changes while the rename is being performed nasty things could happen when we go to release our locks. So introduce a sysfs_rename_mutex to prevent this highly unlikely theoretical issue. In addition hold sysfs_rename_mutex over all calls to sysfs_get_dentry. Allowing sysfs_get_dentry to be simplified in the future. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* sysfs: Rewrite sysfs_drop_dentry.Eric W. Biederman2007-10-12
| | | | | | | | | | | | | Currently we find the dentry to drop by looking at sd->s_dentry. We can just as easily accomplish the same task by looking up the sysfs inode and finding all of the dentries from there, with the added bonus that we don't need to play with the sysfs_assoc_lock. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>