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2011-01-20kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERTDavid Rientjes
The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option is used to configure any non-standard kernel with a much larger scope than only small devices. This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes references to the option throughout the kernel. A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Calling the option "EXPERT" more accurately represents its intention: only expert users who understand the impact of the configuration changes they are making should enable it. Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: David Woodhouse <david.woodhouse@intel.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Greg KH <gregkh@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robin Holt <holt@sgi.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-10Merge branch 'driver-core-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6 * 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: driver core: Document that device_rename() is only for networking sysfs: remove useless test from sysfs_merge_group driver-core: merge private parts of class and bus driver core: fix whitespace in class_attr_string
2011-01-10headers: kobject.h reduxAlexey Dobriyan
Remove kobject.h from files which don't need it, notably, sched.h and fs.h. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-07fs: provide rcu-walk aware permission i_opsNick Piggin
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: rcu-walk aware d_revalidate methodNick Piggin
Require filesystems be aware of .d_revalidate being called in rcu-walk mode (nd->flags & LOOKUP_RCU). For now do a simple push down, returning -ECHILD from all implementations. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: dcache reduce branches in lookup pathNick Piggin
Reduce some branches and memory accesses in dcache lookup by adding dentry flags to indicate common d_ops are set, rather than having to check them. This saves a pointer memory access (dentry->d_op) in common path lookup situations, and saves another pointer load and branch in cases where we have d_op but not the particular operation. Patched with: git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: change d_delete semanticsNick Piggin
Change d_delete from a dentry deletion notification to a dentry caching advise, more like ->drop_inode. Require it to be constant and idempotent, and not take d_lock. This is how all existing filesystems use the callback anyway. This makes fine grained dentry locking of dput and dentry lru scanning much simpler. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2010-11-29sysfs: remove useless test from sysfs_merge_groupAlan Stern
Dan Carpenter pointed out that the new sysfs_merge_group() and sysfs_unmerge_group() routines requires their grp argument to be non-NULL, because they dereference grp to obtain the list of attributes. Hence it's pointless for the routines to include a test and special-case handling for when grp is NULL. This patch (as1433) removes the unneeded tests. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: Dan Carpenter <error27@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-29convert sysfsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (31 commits) driver core: Display error codes when class suspend fails Driver core: Add section count to memory_block struct Driver core: Add mutex for adding/removing memory blocks Driver core: Move find_memory_block routine hpilo: Despecificate driver from iLO generation driver core: Convert link_mem_sections to use find_memory_block_hinted. driver core: Introduce find_memory_block_hinted which utilizes kset_find_obj_hinted. kobject: Introduce kset_find_obj_hinted. driver core: fix build for CONFIG_BLOCK not enabled driver-core: base: change to new flag variable sysfs: only access bin file vm_ops with the active lock sysfs: Fail bin file mmap if vma close is implemented. FW_LOADER: fix kconfig dependency warning on HOTPLUG uio: Statically allocate uio_class and use class .dev_attrs. uio: Support 2^MINOR_BITS minors uio: Cleanup irq handling. uio: Don't clear driver data uio: Fix lack of locking in init_uio_class SYSFS: Allow boot time switching between deprecated and modern sysfs layout driver core: remove CONFIG_SYSFS_DEPRECATED_V2 but keep it for block devices ...
2010-10-22sysfs: only access bin file vm_ops with the active lockEric W. Biederman
bb->vm_ops is a cached copy of the vm_ops of the underlying sysfs bin file, which means that after sysfs_bin_remove_file completes it is only longer valid to deference bb->vm_ops. So move all of the tests of bb->vm_ops inside of where we hold the sysfs active lock. Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-22sysfs: Fail bin file mmap if vma close is implemented.Eric W. Biederman
It is not reasonably possible to wrap vma->close(). To correctly wrap close would imply calling close on any vmas that remain when sysfs_remove_bin_file is called. Finding the proper lists walking them getting the locking right etc, requires deep knowledge of the mm subsystem and as such would require assistence from the mm subsystem to implement. That assistence does not currently exist. Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-17sysfs: Add sysfs_merge_group() and sysfs_unmerge_group()Alan Stern
This patch (as1420) adds sysfs_merge_group() and sysfs_unmerge_group() functions, allowing drivers easily to add and remove sets of attributes to a pre-existing attribute group directory. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-09-03sysfs: checking for NULL instead of ERR_PTRDan Carpenter
d_path() returns an ERR_PTR and it doesn't return NULL. Signed-off-by: Dan Carpenter <error27@gmail.com> Cc: stable <stable@kernel.org> Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-10Merge branch 'for-linus' of ↵Linus Torvalds
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: (96 commits) no need for list_for_each_entry_safe()/resetting with superblock list Fix sget() race with failing mount vfs: don't hold s_umount over close_bdev_exclusive() call sysv: do not mark superblock dirty on remount sysv: do not mark superblock dirty on mount btrfs: remove junk sb_dirt change BFS: clean up the superblock usage AFFS: wait for sb synchronization when needed AFFS: clean up dirty flag usage cifs: truncate fallout mbcache: fix shrinker function return value mbcache: Remove unused features add f_flags to struct statfs(64) pass a struct path to vfs_statfs update VFS documentation for method changes. All filesystems that need invalidate_inode_buffers() are doing that explicitly convert remaining ->clear_inode() to ->evict_inode() Make ->drop_inode() just return whether inode needs to be dropped fs/inode.c:clear_inode() is gone fs/inode.c:evict() doesn't care about delete vs. non-delete paths now ... Fix up trivial conflicts in fs/nilfs2/super.c
2010-08-09switch sysfs to ->evict_inode()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09rename generic_setattrChristoph Hellwig
Despite its name it's now a generic implementation of ->setattr, but rather a helper to copy attributes from a struct iattr to the inode. Rename it to setattr_copy to reflect this fact. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-05sysfs: sysfs_chmod_file's attr can be constJean Delvare
sysfs_chmod_file doesn't change the attribute it operates on, so this attribute can be marked const. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-07-26sysfs: allow creating symlinks from untagged to tagged directoriesEric W. Biederman
Supporting symlinks from untagged to tagged directories is reasonable, and needed to support CONFIG_SYSFS_DEPRECATED. So don't fail a prior allowing that case to work. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-07-26sysfs: sysfs_delete_link handle symlinks from untagged to tagged directories.Eric W. Biederman
This happens for network devices when SYSFS_DEPRECATED is enabled. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-07-26sysfs: Don't allow the creation of symlinks we can't removeEric W. Biederman
Recently my tagged sysfs support revealed a flaw in the device core that a few rare drivers are running into such that we don't always put network devices in a class subdirectory named net/. Since we are not creating the class directory the network devices wind up in a non-tagged directory, but the symlinks to the network devices from /sys/class/net are in a tagged directory. All of which works until we go to remove or rename the symlink. When we remove or rename a symlink we look in the namespace of the target of the symlink. Since the target of the symlink is in a non-tagged sysfs directory we don't have a namespace to look in, and we fail to remove the symlink. Detect this problem up front and simply don't create symlinks we won't be able to remove later. This prevents symlink leakage and fails in a much clearer and more understandable way. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-06-04fix setattr error handling in sysfs, configfsNick Piggin
sysfs and configfs setattr functions have error cases after the generic inode's attributes have been changed. Fix consistency by changing the generic inode attributes only when it is guaranteed to succeed. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-27fs: convert simple fs to new truncateNick Piggin
Convert simple filesystems: ramfs, configfs, sysfs, block_dev to new truncate sequence. Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-21sysfs: add struct file* to bin_attr callbacksChris Wright
This allows bin_attr->read,write,mmap callbacks to check file specific data (such as inode owner) as part of any privilege validation. Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21sysfs: Remove usage of S_BIAS to avoid merge conflict with the vfs treeEric W. Biederman
In Al's latest vfs tree the code is reworked and S_BIAS has been removed. It turns out that checking to see if a super block is in the middle of an unmount in sysfs_exit_ns is unnecessary because we remove the super_block from the s_supers/s_instances list before struct sysfs_super_info pointed to by sb->s_fs_info is freed. For now just delete the unnecessary check to see if a superblock is in the middle of an unmount, it isn't necessary with or without Al's changes and it just causes a needless conflict. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21sysfs: Comment sysfs directory tagging logicSerge E. Hallyn
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>
2010-05-21sysfs: Implement sysfs_delete_linkEric W. Biederman
When removing a symlink sysfs_remove_link does not provide enough information to figure out which tagged directory the symlink falls in. So I need sysfs_delete_link which is passed the target of the symlink to delete. sysfs_rename_link is updated to call sysfs_delete_link instead of sysfs_remove_link as we have all of the information necessary and the callers are interesting. Both of these functions now have enough information to find a symlink in a tagged directory. The only restriction is that they must be called before the target kobject is renamed or deleted. If they are called later I loose track of which tag the target kobject was marked with and can no longer find the old symlink to remove it. This patch was split from an earlier patch. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Benjamin Thery <benjamin.thery@bull.net> Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21sysfs: Add support for tagged directories with untagged members.Eric W. Biederman
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>
2010-05-21sysfs: Implement sysfs tagged directory support.Eric W. Biederman
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>
2010-05-21sysfs: Remove double free sysfs_get_sbEric W. Biederman
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21sysfs: Basic support for multiple super blocksEric W. Biederman
Add all of the necessary bioler plate to support multiple superblocks in sysfs. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-15bridge: update sysfs link names if port device names have changedSimon Arlott
Links for each port are created in sysfs using the device name, but this could be changed after being added to the bridge. As well as being unable to remove interfaces after this occurs (because userspace tools don't recognise the new name, and the kernel won't recognise the old name), adding another interface with the old name to the bridge will cause an error trying to create the sysfs link. This fixes the problem by listening for NETDEV_CHANGENAME notifications and renaming the link. https://bugzilla.kernel.org/show_bug.cgi?id=12743 Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-07sysfs: Kill unused sysfs_sb variable.Eric W. Biederman
Now that there are no more users we can remove the sysfs_sb variable. 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>
2010-03-07sysfs: Pass super_block to sysfs_get_inodeEric W. Biederman
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>
2010-03-07sysfs: Implement sysfs_rename_linkEric W. Biederman
Because of rename ordering problems we occassionally give false warnings about invalid sysfs operations. So using sysfs_rename create a sysfs_rename_link function that doesn't need strange workarounds. Cc: Benjamin Thery <benjamin.thery@bull.net> Cc: Daniel Lezcano <dlezcano@fr.ibm.com> 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>
2010-03-07sysfs: Pack sysfs_dirent more tightly.Eric W. Biederman
Placing the 16bit s_mode between a pointer and a long doesn't pack well especailly on 64bit where we wast 48 bits. So move s_mode and declare it as a unsigned short. This is the sysfs backing store after all we don't need fields extra large just in case someday we want userspace to be able to use a larger value. 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>
2010-03-07sysfs: Serialize updates to the vfs inodeEric W. Biederman
The vfs depends upon filesystem methods to update the vfs inode. Sysfs adds to the normal number of places where the vfs inode is updated by also updatng the vfs inode in sysfs_refresh_inode. Typically the inode mutex is used to serialize updates to the vfs inode, but grabbing the inode mutex in sysfs_permission and sysfs_getattr causes deadlocks, because sometimes the vfs calls those operations with the inode mutex held. Therefore sysfs can not use the inode mutex to serial updates to the vfs inode. The sysfs_mutex is acquired in all of the routines where sysfs updates the vfs inode, and with a small change we can consistently protext sysfs vfs inode updates with the sysfs_mutex. To protect the sysfs vfs inode updates with the sysfs_mutex simply requires extending the scope of sysfs_mutex in sysfs_setattr over inode_setattr, and over inode_change_ok (so we have an unchanging inode when we perform the check). 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>
2010-03-07sysfs: Use one lockdep class per sysfs attribute.Eric W. Biederman
Acknowledge that the logical sysfs rwsem has one instance per sysfs attribute with different locking depencencies for different attributes. There is a sysfs idiom where writing to one sysfs file causes the addition or removal of other sysfs files. Lumping all of the sysfs attributes together in one lock class causes lockdep to generate lots of false positives. This introduces the requirement that non-static sysfs attributes need to be initialized with sysfs_attr_init or sysfs_bin_attr_init. Strictly speaking this requirement only exists when lockdep is enabled, and when lockdep is enabled we get a bit fat warning if this requirement is not met. 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>
2010-03-07sysfs: Only take active references on attributes.Eric W. Biederman
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>
2010-03-07sysfs: Remove sysfs_get/put_active_twoEric W. Biederman
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>
2010-03-07Driver core: Constify struct sysfs_ops in struct kobj_typeEmese Revfy
Constify struct sysfs_ops. This is part of the ops structure constification effort started by Arjan van de Ven et al. Benefits of this constification: * prevents modification of data that is shared (referenced) by many other structure instances at runtime * detects/prevents accidental (but not intentional) modification attempts on archs that enforce read-only kernel data at runtime * potentially better optimized code as the compiler can assume that the const data cannot be changed * the compiler/linker move const data into .rodata and therefore exclude them from false sharing Signed-off-by: Emese Revfy <re.emese@gmail.com> Acked-by: David Teigland <teigland@redhat.com> Acked-by: Matt Domsch <Matt_Domsch@dell.com> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Acked-by: Hans J. Koch <hjk@linutronix.de> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Jens Axboe <jens.axboe@oracle.com> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07sysfs: Cache the last sysfs_dirent to improve readdir scalability v2Eric W. Biederman
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>
2010-03-07sysfs: Add sysfs_add/remove_files utility functionsAndi Kleen
Adding/Removing a whole array of attributes is very common. Add a standard utility function to do this with a simple function call, instead of requiring drivers to open code this. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-02-16sysfs: sysfs_sd_setattr set iattrs unconditionallyEric W. Biederman
There is currently a bug in sysfs_sd_setattr inherited from sysfs_setattr in 2.6.32 where the first time we set the attributes on a sysfs file we allocate backing store but do not set the backing store attributes. Resulting in overly restrictive permissions on sysfs files. The fix is to simply modify the code so that it always executes when we update the sysfs attributes, as we did in 2.6.31 and earlier. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Tested-by: Jean Delvare <khali@linux-fr.org> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-01-04sysfs: Add lockdep annotations for the sysfs active referenceEric W. Biederman
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>
2009-12-23Driver core: bin_attribute parameters can often be const*Phil Carmody
Many struct bin_attribute descriptors are purely read-only structures, and there's no need to change them. Therefore make the promise not to, which will let those descriptors be put in a ro section. Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11sysfs: sysfs_setattr remove unnecessary permission check.Eric W. Biederman
inode_change_ok already clears the SGID bit when necessary so there is no reason for sysfs_setattr to carry code to do the same, and it is good to kill the extra copy because when I moved the code last in certain corner cases the code will look at the wrong gid. 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>
2009-12-11sysfs: Factor out sysfs_rename from sysfs_rename_dir and sysfs_move_dirEric W. Biederman
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>
2009-12-11sysfs: Propagate renames to the vfs on demandEric W. Biederman
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>