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2012-10-24sysfs: sysfs_pathname/sysfs_add_one: Use strlcat() instead of strcat()Geert Uytterhoeven1-8/+8
The warning check for duplicate sysfs entries can cause a buffer overflow when printing the warning, as strcat() doesn't check buffer sizes. Use strlcat() instead. Since strlcat() doesn't return a pointer to the passed buffer, unlike strcat(), I had to convert the nested concatenation in sysfs_add_one() to an admittedly more obscure comma operator construct, to avoid emitting code for the concatenation if CONFIG_BUG is disabled. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-26Merge tag 'driver-core-3.6-rc1' of ↵Linus Torvalds1-0/+10
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core changes from Greg Kroah-Hartman: "Here's the big driver core pull request for 3.6-rc1. Unlike 3.5, this kernel should be a lot tamer, with the printk changes now settled down. All we have here is some extcon driver updates, w1 driver updates, a few printk cleanups that weren't needed for 3.5, but are good to have now, and some other minor fixes/changes in the driver core. All of these have been in the linux-next releases for a while now. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>" * tag 'driver-core-3.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (38 commits) printk: Export struct log size and member offsets through vmcoreinfo Drivers: hv: Change the hex constant to a decimal constant driver core: don't trigger uevent after failure extcon: MAX77693: Add extcon-max77693 driver to support Maxim MAX77693 MUIC device sysfs: fail dentry revalidation after namespace change fix sysfs: fail dentry revalidation after namespace change extcon: spelling of detach in function doc extcon: arizona: Stop microphone detection if we give up on it extcon: arizona: Update cable reporting calls and split headset PM / Runtime: Do not increment device usage counts before probing kmsg - do not flush partial lines when the console is busy kmsg - export "continuation record" flag to /dev/kmsg kmsg - avoid warning for CONFIG_PRINTK=n compilations kmsg - properly print over-long continuation lines driver-core: Use kobj_to_dev instead of re-implementing it driver-core: Move kobj_to_dev from genhd.h to device.h driver core: Move deferred devices to the end of dpm_list before probing driver core: move uevent call to driver_register driver core: fix shutdown races with probe/remove(v3) Extcon: Arizona: Add driver for Wolfson Arizona class devices ...
2012-07-17sysfs: fail dentry revalidation after namespace change fixAndrew Morton1-3/+5
don't assume that KOBJ_NS_TYPE_NONE==0. Also save a test-n-branch. Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Glauber Costa <glommer@parallels.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17sysfs: fail dentry revalidation after namespace changeGlauber Costa1-0/+8
When we change the namespace tag of a sysfs entry, the associated dentry is still kept around. readdir() will work correctly and not display the old entries, but open() will still succeed, so will reads and writes. This will no longer happen if sysfs is remounted, hinting that this is a cache-related problem. I am using the following sequence to demonstrate that: shell1: ip link add type veth unshare -nm shell2: ip link set veth1 <pid_of_shell_1> cat /sys/devices/virtual/net/veth1/ifindex Before that patch, this will succeed (fail to fail). After it, it will correctly return an error. Differently from a normal rename, which we handle fine, changing the object namespace will keep it's path intact. So this check seems necessary as well. [ v2: get type from parent, as suggested by Eric Biederman ] Signed-off-by: Glauber Costa <glommer@parallels.com> CC: Tejun Heo <tj@kernel.org> Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-14sysfs: just use d_materialise_unique()Al Viro1-8/+1
same as for nfs et.al. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14sysfs: switch to ->s_d_op and ->d_release()Al Viro1-10/+6
a) ->d_iput() is wrong here - what we do to inode is completely usual, it's dentry->d_fsdata that we want to drop. Just use ->d_release(). b) switch to ->s_d_op - no need to play with d_set_d_op() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14stop passing nameidata to ->lookup()Al Viro1-1/+1
Just the flags; only NFS cares even about that, but there are legitimate uses for such argument. And getting rid of that completely would require splitting ->lookup() into a couple of methods (at least), so let's leave that alone for now... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14stop passing nameidata * to ->d_revalidate()Al Viro1-2/+2
Just the lookup flags. Die, bastard, die... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-14sysfs: get rid of some lockdep false positivesAlan Stern1-5/+26
This patch (as1554) fixes a lockdep false-positive report. The problem arises because lockdep is unable to deal with the tree-structured locks created by the device core and sysfs. This particular problem involves a sysfs attribute method that unregisters itself, not from the device it was called for, but from a descendant device. Lockdep doesn't understand the distinction and reports a possible deadlock, even though the operation is safe. This is the sort of thing that would normally be handled by using a nested lock annotation; unfortunately it's not feasible to do that here. There's no sensible way to tell sysfs when attribute removal occurs in the context of a parent attribute method. As a workaround, the patch adds a new flag to struct attribute telling sysfs not to inform lockdep when it acquires a readlock on a sysfs_dirent instance for the attribute. The readlock is still acquired, but lockdep doesn't know about it and hence does not complain about impossible deadlock scenarios. Also added are macros for static initialization of attribute structures with the ignore_lockdep flag set. The three offending attributes in the USB subsystem are converted to use the new macros. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Tejun Heo <tj@kernel.org> CC: Eric W. Biederman <ebiederm@xmission.com> CC: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-02sysfs: Removed dup_name entirely in sysfs_renameSasikantha babu1-4/+2
Since no one using "dup_name", removed it completely in sysfs_rename. Signed-off-by: Sasikantha babu <sasikanth.v19@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-10sysfs: handle 'parent deleted before child added'Dan Williams1-0/+3
In scsi at least two cases of the parent device being deleted before the child is added have been observed. 1/ scsi is performing async scans and the device is removed prior to the async can thread running (can happen with an in-opportune / unlikely unplug during initial scan). 2/ libsas discovery event running after the parent port has been torn down (this is a bug in libsas). Result in crash signatures like: BUG: unable to handle kernel NULL pointer dereference at 0000000000000098 IP: [<ffffffff8115e100>] sysfs_create_dir+0x32/0xb6 ... Process scsi_scan_8 (pid: 5417, threadinfo ffff88080bd16000, task ffff880801b8a0b0) Stack: 00000000fffffffe ffff880813470628 ffff88080bd17cd0 ffff88080614b7e8 ffff88080b45c108 00000000fffffffe ffff88080bd17d20 ffffffff8125e4a8 ffff88080bd17cf0 ffffffff81075149 ffff88080bd17d30 ffff88080614b7e8 Call Trace: [<ffffffff8125e4a8>] kobject_add_internal+0x120/0x1e3 [<ffffffff81075149>] ? trace_hardirqs_on+0xd/0xf [<ffffffff8125e641>] kobject_add_varg+0x41/0x50 [<ffffffff8125e70b>] kobject_add+0x64/0x66 [<ffffffff8131122b>] device_add+0x12d/0x63a In this scenario the parent is still valid (because we have a reference), but it has been device_del()'d which means its kobj->sd pointer is NULL'd via: device_del()->kobject_del()->sysfs_remove_dir() ...and then sysfs_create_dir() (without this fix) goes ahead and de-references parent_sd via sysfs_ns_type(): return (sd->s_flags & SYSFS_NS_TYPE_MASK) >> SYSFS_NS_TYPE_SHIFT; This scenario is being fixed in scsi/libsas, but if other subsystems present the same ordering the system need not immediately crash. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: James Bottomley <JBottomley@parallels.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-09sysfs: Update the name hash for an entry after changing the namespaceTom Goff1-1/+1
This is needed to allow renaming network devices that have been moved to another network namespace. Signed-off-by: Tom Goff <thomas.goff@boeing.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-08Revert "sysfs: Kill nlink counting."Greg Kroah-Hartman1-0/+6
This reverts commit 524b6c5b39b931311dfe5a2f5abae2f5c9731676. It has shown to break userspace tools, which is not acceptable. Reported-by: Jiri Slaby <jslaby@suse.cz> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-01-31sysfs: Update the name hash when renaming sysfs entriesEric W. Biederman1-0/+1
This fixes a bug introduced with sysfs name hashes where renaming a network device appears to succeed but silently makes the sysfs files for that network device inaccessible. In at least one configuration this bug has stopped networking from coming up during boot. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Tested-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-24sysfs: Kill nlink counting.Eric W. Biederman1-6/+0
Tracking the number of subdirectories requires an extra field that increases the size of sysfs_dirent. nlinks are not particularly interesting for sysfs and the nlink counts are wrong when network namespaces are involved so stop counting them, and always return nlink == 1. Userspace already knows that directories with nlink == 1 have an nlink count they can't use to count subdirectories. This reduces the size of sysfs_dirent by 8 bytes on 64bit platforms. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-24sysfs: Store the sysfs inode in an unsigned int.Eric W. Biederman1-2/+2
Store the sysfs inode number in an unsided int because ida inode allocator can return at most a 31 bit number, reducing the size of struct sysfs_dirent by 8 bytes on 64bit platforms. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-24sysfs: Add s_hash to sysfs_dirent and order directory entries by hashEric W. Biederman1-103/+116
Compute a 31 bit hash of directory entries (that can fit in a signed 32bit off_t) and index the sysfs directory entries by that hash, replacing the per directory indexes by name and by inode. Because we now only use a single rbtree this reduces the size of sysfs_dirent by 2 pointers. Because we have fewer cases to deal with the code is now simpler. For now I use the simple hash that the dcache uses as that is easy to use and seems simple enough. In addition to makeing the code simpler using a hash for the file position in readdir brings sysfs in line with other filesystems that have non-trivial directory structures. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-11-01sysfs: Make sysfs_rename safe with sysfs_dirents in rbtrees.Eric W. Biederman1-8/+6
In sysfs_rename we need to remove the optimization of not calling sysfs_unlink_sibling and sysfs_link_sibling if the renamed parent directory is not changing. This optimization is no longer valid now that sysfs dirents are stored in an rbtree sorted by name. Move the assignment of s_ns before the call of sysfs_link_sibling. With no sysfs_dirent fields changing after the call of sysfs_link_sibling this allows sysfs_link_sibling to take any of the directory entries into account when it builds the rbtrees, and s_ns looks like a prime canidate to be used in the rbtree in the future. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Jiri Slaby <jirislaby@gmail.com> Cc: Greg KH <gregkh@suse.de> Cc: David Miller <davem@davemloft.net> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-25sysfs: Remove support for tagged directories with untagged members (again)Eric W. Biederman1-4/+4
In commit 8a9ea3237e7e ("Merge git://.../davem/net-next") where my sysfs changes from the net tree merged with the sysfs rbtree changes from Mickulas Patocka the conflict resolution failed to preserve the simplified property that was the point of my changes. That is sysfs_find_dirent can now say something is a match if and only s_name and s_ns match what we are looking for, and sysfs_readdir can simply return all of the directory entries where s_ns matches the directory that we should be returning. Now that we are back to exact matches we can tweak sysfs_find_dirent and the name rb_tree to order sysfs_dirents by s_ns s_name and remove the second loop in sysfs_find_dirent. However that change seems a bit much for a conflict resolution so it can come later. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds1-0/+14
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1745 commits) dp83640: free packet queues on remove dp83640: use proper function to free transmit time stamping packets ipv6: Do not use routes from locally generated RAs |PATCH net-next] tg3: add tx_dropped counter be2net: don't create multiple RX/TX rings in multi channel mode be2net: don't create multiple TXQs in BE2 be2net: refactor VF setup/teardown code into be_vf_setup/clear() be2net: add vlan/rx-mode/flow-control config to be_setup() net_sched: cls_flow: use skb_header_pointer() ipv4: avoid useless call of the function check_peer_pmtu TCP: remove TCP_DEBUG net: Fix driver name for mdio-gpio.c ipv4: tcp: fix TOS value in ACK messages sent from TIME_WAIT rtnetlink: Add missing manual netlink notification in dev_change_net_namespaces ipv4: fix ipsec forward performance regression jme: fix irq storm after suspend/resume route: fix ICMP redirect validation net: hold sock reference while processing tx timestamps tcp: md5: add more const attributes Add ethtool -g support to virtio_net ... Fix up conflicts in: - drivers/net/Kconfig: The split-up generated a trivial conflict with removal of a stale reference to Documentation/networking/net-modules.txt. Remove it from the new location instead. - fs/sysfs/dir.c: Fairly nasty conflicts with the sysfs rb-tree usage, conflicting with Eric Biederman's changes for tagged directories.
2011-10-19sysfs: Reject with a warning invalid uses of tagged directories.Eric W. Biederman1-0/+14
sysfs is a core piece of ifrastructure that many people use and few people have all of the rules in their head on how to use it correctly. Add warnings for people using tagged directories improperly to that any misuses can be caught and diagnosed quickly. A single inexpensive test in sysfs_find_dirent is almost sufficient to catch all possible misuses. An additional warning is needed in sysfs_add_dirent so that we actually fail when attempting to add an untagged dirent in a tagged directory. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-19sysfs: Remove support for tagged directories with untagged members.Eric W. Biederman1-3/+3
Now that /sys/class/net/bonding_masters is implemented as a tagged sysfs file we can remove support for untagged files in tagged directories. This change removes any ambiguity of what a NULL namespace value means. A NULL namespace parameter after this patch means that we are talking about an untagged sysfs dirent. This makes the sysfs code much less prone to mistakes when during maintenance. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-26sysfs: add unsigned long cast to prevent compile warningHeiko Carstens1-1/+2
"sysfs: use rb-tree for inode number lookup" added a new printk which causes a new compile warning on s390 (and few other architectures): fs/sysfs/dir.c: In function 'sysfs_link_sibling': fs/sysfs/dir.c:63:4: warning: format '%lx' expects argument of type 'long unsigned int', but argument 2 has type 'ino_t' [-Wform Add an explicit unsigned long cast since ino_t is an unsigned long on most architectures. Cc: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-08-22sysfs: use rb-tree for inode number lookupMikulas Patocka1-39/+50
sysfs: use rb-tree for inode number lookup This patch makes sysfs use red-black tree for inode number lookup. Together with a previous patch to use red-black tree for name lookup, this patch makes all sysfs lookups to have O(log n) complexity. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-08-22sysfs: remove s_sibling hacksMikulas Patocka1-12/+7
sysfs: remove s_sibling hacks s_sibling was used for three different purposes: 1) as a linked list of entries in the directory 2) as a linked list of entries to be deleted 3) as a pointer to "struct completion" This patch removes the hack and introduces new union u which holds pointers for cases 2) and 3). This change is needed for the following patch that removes s_sibling at all and replaces it with a rb tree. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-08-22sysfs: use rb-tree for name lookupsMikulas Patocka1-7/+50
sysfs: use rb-tree for name lookups Use red-black tree for name lookups. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-08-22sysfs: count subdirectoriesMikulas Patocka1-0/+6
sysfs: count subdirectories This patch introduces a subdirectory counter for each sysfs directory. Without the patch, sysfs_refresh_inode would walk all entries of the directory to calculate the number of subdirectories. This patch improves time of "ls -la /sys/block" when there are 10000 block devices from 9 seconds to 0.19 seconds. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-01-07fs: rcu-walk aware d_revalidate methodNick Piggin1-1/+5
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 Piggin1-1/+1
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 Piggin1-1/+1
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>
2010-05-21sysfs: Comment sysfs directory tagging logicSerge E. Hallyn1-0/+8
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: Add support for tagged directories with untagged members.Eric W. Biederman1-9/+3
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. Biederman1-24/+88
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>
2010-03-07sysfs: Pass super_block to sysfs_get_inodeEric W. Biederman1-1/+1
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: Only take active references on attributes.Eric W. Biederman1-1/+4
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. Biederman1-41/+2
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>
2010-03-07sysfs: Cache the last sysfs_dirent to improve readdir scalability v2Eric W. Biederman1-22/+60
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>
2010-01-04sysfs: Add lockdep annotations for the sysfs active referenceEric W. Biederman1-2/+12
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>
2009-12-11sysfs: Factor out sysfs_rename from sysfs_rename_dir and sysfs_move_dirEric W. Biederman1-33/+29
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. Biederman1-126/+32
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>
2009-12-11sysfs: Gut sysfs_addrm_start and sysfs_addrm_finishEric W. Biederman1-87/+4
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>
2009-12-11sysfs: Implement sysfs_getattr & sysfs_permissionEric W. Biederman1-0/+2
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>
2009-12-11sysfs: Update s_iattr on link and unlink.Eric W. Biederman1-0/+18
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>
2009-12-11sysfs: Use dentry_ops instead of directly playing with the dcacheEric W. Biederman1-27/+46
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>
2009-12-11sysfs: Rename sysfs_d_iput to sysfs_dentry_iputEric W. Biederman1-2/+2
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>
2009-11-05sysfs: Don't leak secdata when a sysfs_dirent is freed.Eric W. Biederman1-0/+4
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>
2009-10-14sysfs: Allow sysfs_move_dir(..., NULL) again.Cornelia Huck1-1/+2
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>
2009-09-10sysfs: Add labeling support for sysfsDavid P. Quigley1-0/+1
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>
2009-07-28sysfs: fix hardlink count on device_movePeter Oberparleiter1-0/+2
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>
2009-03-27Merge branch 'for-linus' of ↵Linus Torvalds1-1/+1
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 ...