07 Jan, 2011
3 commits
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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
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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
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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
22 May, 2010
3 commits
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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
Cc: Eric W. Biederman
Cc: Tejun Heo
Signed-off-by: Greg Kroah-Hartman -
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
Signed-off-by: Greg Kroah-Hartman -
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
Signed-off-by: Benjamin Thery
Signed-off-by: Greg Kroah-Hartman
08 Mar, 2010
4 commits
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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
Acked-by: Serge Hallyn
Signed-off-by: Eric W. Biederman
Signed-off-by: Greg Kroah-Hartman -
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
Acked-by: WANG Cong
Cc: Tejun Heo
Signed-off-by: Greg Kroah-Hartman -
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
Cc: Tejun Heo
Signed-off-by: Greg Kroah-Hartman -
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
Cc: Linus Torvalds
Cc: stable
Signed-off-by: Greg Kroah-Hartman
05 Jan, 2010
1 commit
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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
Acked-by: Tejun Heo
Signed-off-by: Linus Torvalds
12 Dec, 2009
7 commits
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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
Acked-by: Serge Hallyn
Signed-off-by: Eric W. Biederman
Signed-off-by: Greg Kroah-Hartman -
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
Signed-off-by: Eric W. Biederman
Signed-off-by: Greg Kroah-Hartman -
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
Acked-by: Tejun Heo
Signed-off-by: Eric W. Biederman
Signed-off-by: Greg Kroah-Hartman -
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
Acked-by: Serge Hallyn
Signed-off-by: Eric W. Biederman
Signed-off-by: Greg Kroah-Hartman -
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
Acked-by: Serge Hallyn
Signed-off-by: Eric W. Biederman
Signed-off-by: Greg Kroah-Hartman -
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
Acked-by: Serge Hallyn
Signed-off-by: Eric W. Biederman
Signed-off-by: Greg Kroah-Hartman -
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
Acked-by: Serge Hallyn
Signed-off-by: Eric W. Biederman
Signed-off-by: Greg Kroah-Hartman
05 Nov, 2009
1 commit
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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
Acked-by: Serge Hallyn
Signed-off-by: James Morris
15 Oct, 2009
1 commit
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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
Cc: Phil Carmody
Signed-off-by: Greg Kroah-Hartman
10 Sep, 2009
1 commit
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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
Signed-off-by: Stephen D. Smalley
Signed-off-by: James Morris
29 Jul, 2009
1 commit
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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 ueventSigned-off-by: Peter Oberparleiter
Cc: stable
Signed-off-by: Greg Kroah-Hartman
28 Mar, 2009
2 commits
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* '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
... -
Signed-off-by: Al Viro
25 Mar, 2009
2 commits
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Modify sysfs bin files so that we can remove the bin file while they are
still mapped. When the kobject is removed we unmap the bin file and
arrange for future accesses to the mapping to receive SIGBUS.Implementing this prevents a nasty DOS when pci devices are hot plugged
and unplugged. Where if any of their resources were mmaped the kernel
could not free up their pci resources or release their pci data
structures.[akpm@linux-foundation.org: remove unused var]
Signed-off-by: Eric W. Biederman
Cc: Jesse Barnes
Acked-by: Tejun Heo
Cc: Kay Sievers
Signed-off-by: Andrew Morton
Signed-off-by: Greg Kroah-Hartman -
sysfs: sysfs_add_one WARNs with full path to duplicate filename
As a debugging aid, it can be useful to know the full path to a
duplicate file being created in sysfs.We now will display warnings such as:
sysfs: cannot create duplicate filename '/foo'
when attempting to create multiple files named 'foo' in the sysfs
root, or:sysfs: cannot create duplicate filename '/bus/pci/slots/5/foo'
when attempting to create multiple files named 'foo' under a
given directory in sysfs.The path displayed is always a relative path to sysfs_root. The
leading '/' in the path name refers to the sysfs_root mount
point, and should not be confused with the "real" '/'.Thanks to Alex Williamson for essentially writing sysfs_pathname.
Cc: Alex Williamson
Signed-off-by: Alex Chiang
Signed-off-by: Greg Kroah-Hartman
23 Oct, 2008
1 commit
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With this patch all directory fops instances that have a readdir
that doesn't take the BKL are switched to generic_file_llseek.Signed-off-by: Christoph Hellwig
17 Oct, 2008
3 commits
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It finally dawned on me what the clean fix to sysfs_rename_dir
calling kobject_set_name is. Move the work into kobject_rename
where it belongs. The callers serialize us anyway so this is
safe.Signed-off-by: Eric W. Biederman
Acked-by: Tejun Heo
Signed-off-by: Greg Kroah-Hartman -
As inode creation is protected by sysfs_mutex, ilookup5_nowait()
always either fails to find at all or finds one which is fully
initialized, so using ilookup5_nowait() or ilookup5() doesn't make any
difference. Switch to ilookup5() as it's planned to be removed. This
change also makes lookup return value handling a bit simpler.This change was suggested by Al Viro.
Signed-off-by: Tejun Heo
Cc: Al Viro
Signed-off-by: Greg Kroah-Hartman -
Support sysfs_notify from atomic context with new sysfs_notify_dirent
sysfs_notify currently takes sysfs_mutex.
This means that it cannot be called in atomic context.
sysfs_mutex is sometimes held over a malloc (sysfs_rename_dir)
so it can block on low memory.In md I want to be able to notify on a sysfs attribute from
atomic context, and I don't want to block on low memory because I
could be in the writeout path for freeing memory.So:
- export the "sysfs_dirent" structure along with sysfs_get, sysfs_put
and sysfs_get_dirent so I can get the sysfs_dirent that I want to
notify on and hold it in an md structure.
- split sysfs_notify_dirent out of sysfs_notify so the sysfs_dirent
can be notified on with no blocking (just a spinlock).Signed-off-by: Neil Brown
Acked-by: Tejun Heo
Signed-off-by: Greg Kroah-Hartman
27 Jul, 2008
1 commit
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Use WARN() instead of a printk+WARN_ON() pair; this way the message becomes
part of the warning section for better reporting/collection. Also, with this,
one fo the if() sections collapses entirely into the WARN().Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
22 Jul, 2008
1 commit
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driver core: Suppress sysfs warnings for device_rename().
Renaming network devices to an already existing name is not
something we want sysfs to print a scary warning for, since the
callers can deal with this correctly. So let's introduce
sysfs_create_link_nowarn() which gets rid of the common warning.Signed-off-by: Cornelia Huck
Signed-off-by: Greg Kroah-Hartman
15 May, 2008
1 commit
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It is possible that the entry in sysfs already exists, one case of this is
when a network device is renamed to bonding_masters. Anyway, in this case
the proper error path is for device_rename to return an error code, not to
generate bogus backtrace and errors.Also, to avoid possible races, the create link should be done before the
remove link. This makes a device rename atomic operation like other renames.Signed-off-by: Stephen Hemminger
Signed-off-by: Greg Kroah-Hartman
Signed-off-by: David S. Miller
20 Apr, 2008
1 commit
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After an experimental deletion of the unnecessary inclusion of
from the header file , the following
files under fs/sysfs were exposed as needing to explicitly include
.Signed-off-by: Robert P. J. Day
Signed-off-by: Greg Kroah-Hartman
25 Jan, 2008
1 commit
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Signed-off-by: Jean Delvare
Signed-off-by: Greg Kroah-Hartman
17 Jan, 2008
2 commits
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sysfs_rename/move_dir() have the following bugs.
- On dentry lookup failure, kfree() is called on ERR_PTR() value.
- sysfs_move_dir() has an extra dput() on success path.Fix them.
Signed-off-by: Tejun Heo
Signed-off-by: Linus Torvalds -
sysfs tries to keep dcache a strict subset of sysfs_dirent tree by
shooting down dentries when a node is removed, that is, no negative
dentry for sysfs. However, the lookup function returned NULL and thus
created negative dentries when the target node didn't exist.Make sysfs_lookup() return ERR_PTR(-ENOENT) on lookup failure. This
fixes the NULL dereference bug in sysfs_get_dentry() discovered by
bluetooth rfcomm device moving around.Signed-off-by: Tejun Heo
Signed-off-by: Linus Torvalds
31 Oct, 2007
1 commit
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sysfs_{get,put}_active() can now become static.
Signed-off-by: Adrian Bunk
Signed-off-by: Greg Kroah-Hartman
17 Oct, 2007
2 commits
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Replace some SPIN_LOCK_UNLOCKED with DEFINE_SPINLOCK
Signed-off-by: Roel Kluin
Acked-by: Thomas Gleixner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Try to fix the mess created by sysfs braindamage.
- refactor code internal to fs/namei.c a little to avoid too much
duplication:
o __lookup_hash_kern is renamed back to __lookup_hash
o the old __lookup_hash goes away, permission checks moves to
the two callers
o useless inline qualifiers on above functions go away
- lookup_one_len_kern loses it's last argument and is renamed to
lookup_one_noperm to make it's useage a little more clear
- added kerneldoc comments to describe lookup_one_len aswell as
lookup_one_noperm and make it very clear that no one should use
the latter ever.Signed-off-by: Christoph Hellwig
Cc: Josef 'Jeff' Sipek
Cc: Miklos Szeredi
Cc: Al Viro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
