Sysfs file poll implementation is scattered over sysfs and kobject.
Event numbering is done in sysfs_dirent but wait itself is done on
kobject. This not only unecessarily bloats both kobject and
sysfs_dirent but is also buggy - if a sysfs_dirent is removed while
there still are pollers, the associaton betwen the kobject and
sysfs_dirent breaks and kobject may be freed with the pollers still
sleeping on it.
This patch moves whole poll implementation into sysfs_open_dirent.
Each time a sysfs_open_dirent is created, event number restarts from 1
and pollers sleep on sysfs_open_dirent. As event sequence number is
meaningless without any open file and pollers should have open file
and thus sysfs_open_dirent, this ephemeral event counting works and is
a saner implementation.
This patch fixes the dnagling sleepers bug and reduces the sizes of
kobject and sysfs_dirent by one pointer.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Implement sysfs_open_dirent which represents an open file (attribute)
sysfs_dirent. A file sysfs_dirent with one or more open files have
one sysfs_dirent and all sysfs_buffers (one for each open instance)
are linked to it.
sysfs_open_dirent doesn't actually do anything yet but will be used to
off-load things which are specific for open file sysfs_dirent from it.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Children list head is only meaninful for directory nodes. Move it
into s_dir. This doesn't save any space currently but it will with
further changes.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs_root is different from a regular directory dirent in that it's
of type SYSFS_ROOT and doesn't have a name. These differences aren't
used by anybody and only adds to complexity. Make sysfs_root a
regular directory dirent.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs_attach_dentry() now has only one caller and isn't doing much
other than obfuscating the code. Open code and kill it.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make s_elem an anonymous union. Prefixing with s_elem makes things
needlessly longer without any advantage.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
All bin attr operations require active references of itself and its
parent. There's no reason to allow open when its parent has been
deactivated and allowing it is inconsistent with regular sysfs file.
Use sysfs_get_active_two() in bin attribute open function.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In sysfs_release(), sysfs_buffer pointed to by filp->private_data is
guaranteed to exist. Kill the unnecessary NULL check. This also
makes the code more consistent with the counterpart in fs/sysfs/bin.c.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There's no reason to get an extra reference to sysfs_dirent for an
open file. Open file has a reference to the dentry which in turn has
a reference to sysfs_dirent. This is fairly obvious as otherwise open
itself won't be able to access the sysfs_dirent. Kill the extra
sysfs_get() and matching sysfs_put().
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Move s_mode downward such that it's side-by-side with s_iattr which is
used for the same thing.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs_update_file() depends on inode->i_mtime but sysfs iondes are now
reclaimable making the reported modification time unreliable. There's
only one user (pci hotplug) of this notification mechanism and it
reportedly isn't utilized from userland.
Kill sysfs_update_file().
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs is about to go through major overhaul making this a pretty good
opportunity to clean up (out-of-tree changes and pending patches will
need regeneration anyway). Clean up headers.
* Kill space between * and symbolname.
* Move SYSFS_* type constants and flags into fs/sysfs/sysfs.h.
They're internal to sysfs.
* Reformat function prototypes and add argument symbol names.
* Make dummy function definition order match that of function
prototypes.
* Add some comments.
* Reorganize fs/sysfs/sysfs.h according to which file the declared
variable or feature lives in.
This patch does not introduce any behavior change.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs_chmod_file() looked and updated only inode of the target file.
Dentry and inode are reclaimable and the update mode data will go away
when the inode is reclaimed. This patch makes sysfs_chmod_file()
update sd->s_mode too such that the change is permanent.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs_add/remove_one() now link and unlink the target dirent into and
from the children list. Update comments accordingly.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We want to let people know when we create a duplicate sysfs file, as
they need to fix up their code.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch rewrites sysfs_move_dir to perform it's checks
as much as possible on the underlying sysfs_dirents instead
of the contents of the dcache, making sysfs_move_dir
more like the rest of the sysfs directory modification
code.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch rewrites sysfs_rename_dir to perform it's checks
as much as possible on the underlying sysfs_dirents instead
of the contents of the dcache. It turns out that this version
is a little simpler, and a little more like the rest of
the sysfs directory modification code.
tj: fixed double locking of sysfs_mutex
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The only uses of s_dentry left are the code that maintains
s_dentry and trivial users that don't actually need it.
So this patch removes the s_dentry maintenance code and
restructures the trivial uses to use something else.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Now that we know the sysfs tree structure cannot change under us and
sysfs shadow support is dropped, sysfs_get_dentry() can be simplified
greatly. It can just look up from the root and there's no need to
retry on failure.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Looking carefully at the rename code we have a subtle dependency
that the structure of sysfs not change while we are performing
a rename. If the parent directory of the object we are renaming
changes while the rename is being performed nasty things could
happen when we go to release our locks.
So introduce a sysfs_rename_mutex to prevent this highly
unlikely theoretical issue.
In addition hold sysfs_rename_mutex over all calls to
sysfs_get_dentry. Allowing sysfs_get_dentry to be simplified
in the future.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Currently we find the dentry to drop by looking at sd->s_dentry.
We can just as easily accomplish the same task by looking up the
sysfs inode and finding all of the dentries from there, with the
added bonus that we don't need to play with the sysfs_assoc_lock.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
At some point someone wrote sysfs_readdir to insert a cursor
into the list of sysfs_dirents to ensure that sysfs_readdir would
restart properly. That works but it is complex code and tends
to be expensive.
The same effect can be achieved by keeping the sysfs_dirents in
inode order and using the inode number as the f_pos. Then
when we restart we just have to find the first dirent whose inode
number is equal or greater then the last sysfs_dirent we attempted
to return.
Removing the sysfs directory cursor also allows the remove of
all of the mysterious checks for sysfs_type(sd) != 0. Which
were nonbovious checks to see if a cursor was in a directory list.
tj: offset marker for EOF is changed from UINT_MAX to INT_MAX to avoid
overflow in case offset is 32bit.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is a small cleanup patch that makes the code just
a little bit cleaner.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch modifies the users of sysfs_mount to use sysfs_root
instead (which is what they are looking for). It then
makes sysfs_mount static to keep people from using it
by accident.
The net result is slightly faster and cleaner code.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Since sysfs no longer stores fs directory information in the dcache
on a permanent basis kill_litter_super it is inappropriate and actively
wrong. It will decrement the count on all dentries left in the
dcache before trying to free them.
At the moment this is not biting us only because we never unmount sysfs.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Now that sysfs_get_inode is dropping the inode lock
we no longer have a need from sysfs_instantiate.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
lookup_one_len_kern() should be called with the parent's i_mutex
locked. Fix it.
Spotted by Eric W. Biederman.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
With the previous sysfs_add_one() update, there is only one user of
the return value of sysfs_addrm_finish() and the user can switch to
testing @sd easily. Make sysfs_addrm_finish() return void for cleaner
semantics as suggested by Satyam Sharma.
This patch doesn't introduce any noticeable behavior change.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Satyam Sharma <satyam.sharma@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make sysfs_add_one() check for duplicate entry and return -EEXIST if
such entry exists. This simplifies node addition code a bit.
This patch doesn't introduce any noticeable behavior change.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When adding or removing a sysfs_dirent, the user used to be required
to call link/unlink separately. It was for two reasons - code looked
like that before sysfs_addrm_cxt conversion and to avoid looping
through parent_sd->children list twice during removal.
Performance optimization during removal just isn't worth it. Make
sysfs_add/remove_one() call sysfs_link/unlink_sibing() implicitly.
This makes code simpler albeit slightly less efficient. This change
doesn't introduce any noticeable behavior change.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
With the shadow directories gone, sysfs_rename_dir() can be simplified.
* parent doesn't need to be grabbed separately. Just access
old_dentry->d_parent.
* parent sd can never change. Remove code to move under the new
parent.
* Massage comments a bit.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* remove space between * and symbol name in variable declaration.
* kill unnecessary new line.
* kill 'found' and test 'sd' instead.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
While shadow directories appear to be a good idea, the current scheme
of controlling their creation and destruction outside of sysfs appears
to be a locking and maintenance nightmare in the face of sysfs
directories dynamically coming and going. Which can now occur for
directories containing network devices when CONFIG_SYSFS_DEPRECATED is
not set.
This patch removes everything from the initial shadow directory support
that allowed the shadow directory creation to be controlled at a higher
level. So except for a few bits of sysfs_rename_dir everything from
commit b592fcfe7f is now gone.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use mutex instead of semaphore in sysfs/file.c : sys_buffer.
Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Allows debugfs helper functions to have a hex output, rather than just decimal
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
A kset should not have its name set directly, so dynamically set the
name at runtime.
This is needed to remove the static array in the kobject structure which
will be changed in a future patch.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
A number of different drivers incorrect access the kobject name field
directly. This is not correct as the name might not be in the array.
Use the proper accessor function instead.
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (408 commits)
[POWERPC] Add memchr() to the bootwrapper
[POWERPC] Implement logging of unhandled signals
[POWERPC] Add legacy serial support for OPB with flattened device tree
[POWERPC] Use 1TB segments
[POWERPC] XilinxFB: Allow fixed framebuffer base address
[POWERPC] XilinxFB: Add support for custom screen resolution
[POWERPC] XilinxFB: Use pdata to pass around framebuffer parameters
[POWERPC] PCI: Add 64-bit physical address support to setup_indirect_pci
[POWERPC] 4xx: Kilauea defconfig file
[POWERPC] 4xx: Kilauea DTS
[POWERPC] 4xx: Add AMCC Kilauea eval board support to platforms/40x
[POWERPC] 4xx: Add AMCC 405EX support to cputable.c
[POWERPC] Adjust TASK_SIZE on ppc32 systems to 3GB that are capable
[POWERPC] Use PAGE_OFFSET to tell if an address is user/kernel in SW TLB handlers
[POWERPC] 85xx: Enable FP emulation in MPC8560 ADS defconfig
[POWERPC] 85xx: Killed <asm/mpc85xx.h>
[POWERPC] 85xx: Add cpm nodes for 8541/8555 CDS
[POWERPC] 85xx: Convert mpc8560ads to the new CPM binding.
[POWERPC] mpc8272ads: Remove muram from the CPM reg property.
[POWERPC] Make clockevents work on PPC601 processors
...
Fixed up conflict in Documentation/powerpc/booting-without-of.txt manually.
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (867 commits)
[SKY2]: status polling loop (post merge)
[NET]: Fix NAPI completion handling in some drivers.
[TCP]: Limit processing lost_retrans loop to work-to-do cases
[TCP]: Fix lost_retrans loop vs fastpath problems
[TCP]: No need to re-count fackets_out/sacked_out at RTO
[TCP]: Extract tcp_match_queue_to_sack from sacktag code
[TCP]: Kill almost unused variable pcount from sacktag
[TCP]: Fix mark_head_lost to ignore R-bit when trying to mark L
[TCP]: Add bytes_acked (ABC) clearing to FRTO too
[IPv6]: Update setsockopt(IPV6_MULTICAST_IF) to support RFC 3493, try2
[NETFILTER]: x_tables: add missing ip6t_modulename aliases
[NETFILTER]: nf_conntrack_tcp: fix connection reopening
[QETH]: fix qeth_main.c
[NETLINK]: fib_frontend build fixes
[IPv6]: Export userland ND options through netlink (RDNSS support)
[9P]: build fix with !CONFIG_SYSCTL
[NET]: Fix dev_put() and dev_hold() comments
[NET]: make netlink user -> kernel interface synchronious
[NET]: unify netlink kernel socket recognition
[NET]: cleanup 3rd argument in netlink_sendskb
...
Fix up conflicts manually in Documentation/feature-removal-schedule.txt
and my new least favourite crap, the "mod_devicetable" support in the
files include/linux/mod_devicetable.h and scripts/mod/file2alias.c.
(The latter files seem to be explicitly _designed_ to get conflicts when
different subsystems work with them - that have an absolutely horrid
lack of subsystem separation!)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch make processing netlink user -> kernel messages synchronious.
This change was inspired by the talk with Alexey Kuznetsov about current
netlink messages processing. He says that he was badly wrong when introduced
asynchronious user -> kernel communication.
The call netlink_unicast is the only path to send message to the kernel
netlink socket. But, unfortunately, it is also used to send data to the
user.
Before this change the user message has been attached to the socket queue
and sk->sk_data_ready was called. The process has been blocked until all
pending messages were processed. The bad thing is that this processing
may occur in the arbitrary process context.
This patch changes nlk->data_ready callback to get 1 skb and force packet
processing right in the netlink_unicast.
Kernel -> user path in netlink_unicast remains untouched.
EINTR processing for in netlink_run_queue was changed. It forces rtnl_lock
drop, but the process remains in the cycle until the message will be fully
processed. So, there is no need to use this kludges now.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
This function allocates the zeroed chunk of memory and
call seq_open(). The __seq_open_private() helper returns
the allocated memory to make it possible for the caller
to initialize it.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
With the net namespaces many code leaved the __init section,
thus making the kernel occupy more memory than it did before.
Since we have a config option that prohibits the namespace
creation, the functions that initialize/finalize some netns
stuff are simply not needed and can be freed after the boot.
Currently, this is almost not noticeable, since few calls
are no longer in __init, but when the namespaces will be
merged it will be possible to free more code. I propose to
use the __net_init, __net_exit and __net_initdata "attributes"
for functions/variables that are not used if the CONFIG_NET_NS
is not set to save more space in memory.
The exiting functions cannot just reside in the __exit section,
as noticed by David, since the init section will have
references on it and the compilation will fail due to modpost
checks. These references can exist, since the init namespace
never dies and the exit callbacks are never called. So I
introduce the __exit_refok attribute just like it is already
done with the __init_refok.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The problem: proc_net files remember which network namespace the are
against but do not remember hold a reference count (as that would pin
the network namespace). So we currently have a small window where
the reference count on a network namespace may be incremented when opening
a /proc file when it has already gone to zero.
To fix this introduce maybe_get_net and get_proc_net.
maybe_get_net increments the network namespace reference count only if it is
greater then zero, ensuring we don't increment a reference count after it
has gone to zero.
get_proc_net handles all of the magic to go from a proc inode to the network
namespace instance and call maybe_get_net on it.
PROC_NET the old accessor is removed so that we don't get confused and use
the wrong helper function.
Then I fix up the callers to use get_proc_net and handle the case case
where get_proc_net returns NULL. In that case I return -ENXIO because
effectively the network namespace has already gone away so the files
we are trying to access don't exist anymore.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add the appropriate EXPORT_SYMBOLS for proc_net_create,
proc_net_fops_create and proc_net_remove to fix errors when
compiling allmodconfig
Signed-off-by: Mark Nelson <markn@au1.ibm.com>
Acked-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Tejun Heo