This patch (as869) reinstates the mutual exclusion between sysfs
attribute method calls and attribute unregistration. The
previously-reported deadlocks have been fixed, and this exclusion is
by far the simplest way to avoid races during driver unbinding.
The check for orphaned read-buffers has been moved down slightly, so
that the remainder of a partially-read buffer will still be available
to userspace even after the attribute has been unregistered.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Suspend deadlocks when trying to unregister /sys/block/sr0.
This comes from Oliver's commit 94bebf4d1b
"Driver core: fix race in sysfs between sysfs_remove_file() and
read()/write()".
sysfs_write_file downs buffer->sem while calling flush_write_buffer, and
flushing that particular write buffer entails downing buffer->sem in
orphan_all_buffers, resulting in the obvious self-deadlock.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Many struct inode_operations in the kernel can be "const". Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data. In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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/*.
What I want is a separate /sys/class/net directory in sysfs for each
network namespace, and I want to name each of them /sys/class/net.
I looked and the VFS actually allows that. All that is needed is
for /sys/class/net to implement a follow link method to redirect
lookups to the real directory you want.
Implementing a follow link method that is sensitive to the current
network namespace turns out to be 3 lines of code so it looks like a
clean approach. Modifying sysfs so it doesn't get in my was is a bit
trickier.
I am calling the concept of multiple directories all at the same path
in the filesystem shadow directories. With the directory entry really
at that location the shadow master.
The following patch modifies sysfs so it can handle a directory
structure slightly different from the kobject tree so I can implement
the shadow directories for handling /sys/class/net/.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch prevents a race between IO and removing a file from sysfs.
It introduces a list of sysfs_buffers associated with a file at the inode.
Upon removal of a file the list is walked and the buffers marked orphaned.
IO to orphaned buffers fails with -ENODEV. The driver can safely free
associated data structures or be unloaded.
Signed-off-by: Oliver Neukum <oliver@neukum.name>
Acked-by: Maneesh Soni <maneesh@in.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This eliminates the i_blksize field from struct inode. Filesystems that want
to provide a per-inode st_blksize can do so by providing their own getattr
routine instead of using the generic_fillattr() function.
Note that some filesystems were providing pretty much random (and incorrect)
values for i_blksize.
[bunk@stusta.de: cleanup]
[akpm@osdl.org: generic_fillattr() fix]
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make sysfs_remove_bin_file() void. If it detects an error,
printk the file name and call dump_stack().
sysfs_hash_and_remove() now returns an error code indicating
its success or failure so that sysfs_remove_bin_file() can
know success/failure.
Convert the only driver that checked the return value of
sysfs_remove_bin_file().
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sysfs has a different i_mutex lock order behavior for i_mutex than the
other filesystems; sysfs i_mutex is called in many places with subsystem
locks held. At the same time, many of the VFS locking rules do not apply
to sysfs at all (cross directory rename for example). To untangle this
mess (which gives false positives in lockdep), we're giving sysfs inodes
their own class for i_mutex.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Same as with already do with the file operations: keep them in .rodata and
prevents people from doing runtime patching.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Steven French <sfrench@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
this converts fs/sysfs to kzalloc() usage.
compile tested with make allyesconfig
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When calling sysfs_remove_dir() don't allow any further sysfs functions
to work for this kobject anymore. This fixes a nasty USB cdc-acm oops
on disconnect.
Many thanks to Bob Copeland and Paul Fulghum for taking the time to
track this down.
Cc: Bob Copeland <email@bobcopeland.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
fs: Use <linux/capability.h> where capable() is used.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch converts the inode semaphore to a mutex. I have tested it on
XFS and compiled as much as one can consider on an ia64. Anyway your
luck with it might be different.
Modified-by: Ingo Molnar <mingo@elte.hu>
(finished the conversion)
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The problem arises if an entity in sysfs is created and removed without
ever having been made completely visible. In SCSI this is triggered by
removing a device while it's initialising.
The problem appears to be that because it was never made visible in sysfs,
the sysfs dentry has a null d_inode which oopses when a reference is made
to it. The solution is simply to check d_inode and assume the object was
never made visible (and thus doesn't need deleting) if it's NULL.
(akpm: possibly a stopgap for 2.6.13 scsi problems. May not be the
long-term fix)
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
o sysfs_dirent's s_mode field should also be updated in sysfs_setattr(), else
there could be inconsistency in the two fields. s_mode is used while
->readdir so as not to bring in the inode to cache.
Signed-off-by: Maneesh Soni <maneesh@in.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Various filesystem drivers have grown a get_dentry() function that's a
duplicate of lookup_one_len, except that it doesn't take a maximum length
argument and doesn't check for \0 or / in the passed in filename.
Switch all these places to use lookup_one_len.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Greg KH <greg@kroah.com>
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
o Following patch sets the attributes for newly allocated inodes for sysfs
objects. If the object has non-default attributes, inode attributes are
set as saved in sysfs_dirent->s_iattr, pointer to struct iattr.
Signed-off-by: Maneesh Soni <maneesh@in.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
o This adds ->i_op->setattr VFS method for sysfs inodes. The changed
attribues are saved in the persistent sysfs_dirent structure as a pointer
to struct iattr. The struct iattr is allocated only for those sysfs_dirent's
for which default attributes are getting changed. Thanks to Jon Smirl for
this suggestion.
Signed-off-by: Maneesh Soni <maneesh@in.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
