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>
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>
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>
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>
Pull vfs pile 1 from Al Viro:
"This is _not_ all; in particular, Miklos' and Jan's stuff is not there
yet."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (64 commits)
ext4: initialization of ext4_li_mtx needs to be done earlier
debugfs-related mode_t whack-a-mole
hfsplus: add an ioctl to bless files
hfsplus: change finder_info to u32
hfsplus: initialise userflags
qnx4: new helper - try_extent()
qnx4: get rid of qnx4_bread/qnx4_getblk
take removal of PF_FORKNOEXEC to flush_old_exec()
trim includes in inode.c
um: uml_dup_mmap() relies on ->mmap_sem being held, but activate_mm() doesn't hold it
um: embed ->stub_pages[] into mmu_context
gadgetfs: list_for_each_safe() misuse
ocfs2: fix leaks on failure exits in module_init
ecryptfs: make register_filesystem() the last potential failure exit
ntfs: forgets to unregister sysctls on register_filesystem() failure
logfs: missing cleanup on register_filesystem() failure
jfs: mising cleanup on register_filesystem() failure
make configfs_pin_fs() return root dentry on success
configfs: configfs_create_dir() has parent dentry in dentry->d_parent
configfs: sanitize configfs_create()
...
This reverts commit 524b6c5b39.
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>
This was done to resolve a merge and build problem with the
drivers/acpi/processor_driver.c file.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
There is a misleading difference between /proc and /sys permissions, /proc is 0555 and /sys is 0755. But
as it is impossible to create or unlink something in /sys it would be nice to have same permissions.
Signed-off-by: Vitaly Kuznetsov <vitty@altlinux.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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>
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>
On 32bit this reduces sizeof(struct sysfs_dirent) by 2 bytes.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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>
Recently an OOPS was observed from the usb serial io_ti driver when it tried to remove
sysfs directories. Upon investigation it turns out this driver was always buggy
and that a recent sysfs change had stopped guarding itself against removing attributes
from sysfs directories that had already been removed. :(
Historically we have been silent about attempting to files from nonexistent sysfs
directories and have politely returned error codes. That has resulted in people writing
broken code that ignores the error codes.
Issue a kernel WARNING and a stack backtrace to make it clear in no uncertain
terms that abusing sysfs is not ok, and the callers need to fix their code.
This change transforms the io_ti OOPS into a more comprehensible error message
and stack backtrace.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Reported-by: Wolfgang Frisch <wfpub@roembden.net>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Replace remaining direct i_nlink updates with a new set_nlink()
updater function.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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>
In commit 8a9ea3237e ("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>
* 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.
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>
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>
Looking up files in sysfs is hard to understand and analyize because we
currently allow placing untagged files in tagged directories. In the
implementation of that we have two subtly different meanings of NULL.
NULL meaning there is no tag on a directory entry and NULL meaning
we don't care which namespace the lookup is performed for. This
multiple uses of NULL have resulted in subtle bugs (since fixed)
in the code.
Currently it is only the bonding driver that needs to have an untagged
file in a tagged directory.
To untagle this mess I am adding support for tagged files to sysfs.
Modifying the bonding driver to implement bonding_masters as a tagged
file. Registering bonding_masters once for each network namespace.
Then I am removing support for untagged entries in tagged sysfs
directories.
Resulting in code that is much easier to reason about.
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>
"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>
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>
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>
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>
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>
its value depends only on inode and does not change; we might as
well store it in ->i_op->check_acl and be done with that.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* new refcount in struct net, controlling actual freeing of the memory
* new method in kobj_ns_type_operations (->drop_ns())
* ->current_ns() semantics change - it's supposed to be followed by
corresponding ->drop_ns(). For struct net in case of CONFIG_NET_NS it bumps
the new refcount; net_drop_ns() decrements it and calls net_free() if the
last reference has been dropped. Method renamed to ->grab_current_ns().
* old net_free() callers call net_drop_ns() instead.
* sysfs_exit_ns() is gone, along with a large part of callchain
leading to it; now that the references stored in ->ns[...] stay valid we
do not need to hunt them down and replace them with NULL. That fixes
problems in sysfs_lookup() and sysfs_readdir(), along with getting rid
of sb->s_instances abuse.
Note that struct net *shutdown* logics has not changed - net_cleanup()
is called exactly when it used to be called. The only thing postponed by
having a sysfs instance refering to that struct net is actual freeing of
memory occupied by struct net.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
On some arches (x86, sh, arm, unicore, powerpc) the oops message would
print out the last sysfs file accessed.
This was very useful in finding a number of sysfs and driver core bugs
in the 2.5 and early 2.6 development days, but it has been a number of
years since this file has actually helped in debugging anything that
couldn't also be trivially determined from the stack traceback.
So it's time to delete the line. This is good as we need all the space
we can get for oops messages at times on consoles.
Acked-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix what is clearly a simple copy-and-paste error in commenting the
sysfs_update_group() routine.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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>
* '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
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>
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>
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>
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>
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>
* 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
...
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>
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>
