1. 09 Aug, 2010 1 commit
  2. 04 Jun, 2010 2 commits
  3. 28 May, 2010 1 commit
  4. 21 May, 2010 2 commits
    • Eric W. Biederman's avatar
      sysfs: Implement sysfs tagged directory support. · 3ff195b0
      Eric W. Biederman authored
      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      - sysfs_exit_ns when an individual tag is no longer valid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: default avatarEric W. Biederman <ebiederm@xmission.com>
      Signed-off-by: default avatarBenjamin Thery <benjamin.thery@bull.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      3ff195b0
    • Eric W. Biederman's avatar
      sysfs: Add support for tagged directories with untagged members. · af10ec77
      Eric W. Biederman authored
      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: default avatarEric W. Biederman <ebiederm@aristanetworks.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      af10ec77
  5. 30 Mar, 2010 1 commit
    • Tejun Heo's avatar
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo authored
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Guess-its-ok-by: default avatarChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  6. 08 Mar, 2010 2 commits
  7. 16 Feb, 2010 1 commit
  8. 11 Dec, 2009 7 commits
  9. 11 Sep, 2009 1 commit
  10. 10 Sep, 2009 1 commit
    • David P. Quigley's avatar
      sysfs: Add labeling support for sysfs · ddd29ec6
      David P. Quigley authored
      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: default avatarDavid P. Quigley <dpquigl@tycho.nsa.gov>
      Signed-off-by: default avatarStephen D. Smalley <sds@tycho.nsa.gov>
      Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      ddd29ec6
  11. 24 Mar, 2009 1 commit
  12. 05 Jan, 2009 1 commit
  13. 30 Apr, 2008 2 commits
    • Ben Hutchings's avatar
      sysfs: Disallow truncation of files in sysfs · 40a2159a
      Ben Hutchings authored
      sysfs allows attribute files to be truncated, e.g. using ftruncate(), with the
      expected effect on their inode.   For most attributes, this doesn't change the
      "real" size of the file i.e. how much can be read from it.  However, the
      parameter validation for reading and writing binary attribute files is based
      on the inode size and not the size specified in the file's bin_attribute, so it
      can be broken by this. For example, if we try using dd to write to such a file:
      
      # pwd
      /sys/bus/pci/devices/0000:08:00.0
      # ls -l config
      -rw-r--r--  1 root root 4096 Feb  1 17:35 config
      # dd if=/dev/zero of=config bs=4 count=1
      1+0 records in
      1+0 records out
      # ls -l config
      -rw-r--r--  1 root root 0 Feb  1 17:50 config
      # dd if=/dev/zero of=config bs=4 count=1 seek=128
      dd: writing `config': No space left on device
      1+0 records in
      0+0 records out
      
      Also, after truncation to 0, parameter validation for read and write is
      disabled.  Most bin_attribute read and write methods also validate the size and
      offset, but for some this will allow out-of-range access.  This may be a
      security issue, though access to such files is often limited to root.  In any
      case, the validation should remain for safety's sake!)
      
      This was previously reported in Bugzilla as bug 9867.
      
      sysfs should ignore size changes or else refuse them (by returning -EINVAL).
      This patch makes it ignore them.
      Signed-off-by: default avatarBen Hutchings <bhutchings@solarflare.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      40a2159a
    • Miklos Szeredi's avatar
      mm: bdi: add separate writeback accounting capability · e4ad08fe
      Miklos Szeredi authored
      Add a new BDI capability flag: BDI_CAP_NO_ACCT_WB.  If this flag is
      set, then don't update the per-bdi writeback stats from
      test_set_page_writeback() and test_clear_page_writeback().
      
      Misc cleanups:
      
       - convert bdi_cap_writeback_dirty() and friends to static inline functions
       - create a flag that includes all three dirty/writeback related flags,
         since almst all users will want to have them toghether
      Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e4ad08fe
  14. 17 Oct, 2007 1 commit
  15. 16 Oct, 2007 1 commit
  16. 12 Oct, 2007 10 commits
  17. 18 Jul, 2007 1 commit
  18. 11 Jul, 2007 4 commits
    • Tejun Heo's avatar
      sysfs: move sysfs_drop_dentry() to dir.c and make it static · a0edd7c8
      Tejun Heo authored
      After add/remove path restructuring, the only user of
      sysfs_drop_dentry() is sysfs_addrm_finish().  Move sysfs_drop_dentry()
      to dir.c and make it static.
      Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      a0edd7c8
    • Tejun Heo's avatar
      sysfs: restructure add/remove paths and fix inode update · fb6896da
      Tejun Heo authored
      The original add/remove code had the following problems.
      
      * parent's timestamps are updated on dentry instantiation.  this is
        incorrect with reclaimable files.
      
      * updating parent's timestamps isn't synchronized.
      
      * parent nlink update assumes the inode is accessible which won't be
        true once directory dentries are made reclaimable.
      
      This patch restructures add/remove paths to resolve the above
      problems.  Add/removal are done in the following steps.
      
      1. sysfs_addrm_start() : acquire locks including sysfs_mutex and other
         resources.
      
      2-a. sysfs_add_one() : add new sd.  linking the new sd into the
           children list is caller's responsibility.
      
      2-b. sysfs_remove_one() : remove a sd.  unlinking the sd from the
           children list is caller's responsibility.
      
      3. sysfs_addrm_finish() : release all resources and clean up.
      
      Steps 2-a and/or 2-b can be repeated multiple times.
      
      Parent's inode is looked up during sysfs_addrm_start().  If available
      (always at the moment), it's pinned and nlink is updated as sd's are
      added and removed.  Timestamps are updated during finish if any sd has
      been added or removed.  If parent's inode is not available during
      start, sysfs_mutex ensures that parent inode is not created till
      add/remove is complete.
      
      All the complexity is contained inside the helper functions.
      Especially, dentry/inode handling is properly hidden from the rest of
      sysfs which now mostly operate on sysfs_dirents.  As an added bonus,
      codes which use these helpers to add and remove sysfs_dirents are now
      more structured and simpler.
      Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      fb6896da
    • Tejun Heo's avatar
      sysfs: use sysfs_mutex to protect the sysfs_dirent tree · 3007e997
      Tejun Heo authored
      As kobj sysfs dentries and inodes are gonna be made reclaimable,
      i_mutex can't be used to protect sysfs_dirent tree.  Use sysfs_mutex
      globally instead.  As the whole tree is protected with sysfs_mutex,
      there is no reason to keep sysfs_rename_sem.  Drop it.
      
      While at it, add docbook comments to functions which require
      sysfs_mutex locking.
      Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      3007e997
    • Tejun Heo's avatar
      sysfs: consolidate sysfs spinlocks · 5f995323
      Tejun Heo authored
      Replace sysfs_lock and kobj_sysfs_assoc_lock with sysfs_assoc_lock.
      sysfs_lock was originally to be used to protect sysfs_dirent tree but
      mutex seems better choice, so there is no reason to keep sysfs_lock
      separate.  Merge the two spinlocks into one.
      Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      5f995323