1. 17 Dec, 2013 1 commit
    • Tejun Heo's avatar
      kernfs: add @mode to kernfs_create_dir[_ns]() · bb8b9d09
      Tejun Heo authored
      sysfs assumed 0755 for all newly created directories and kernfs
      inherited it.  This assumption is unnecessarily restrictive and
      inconsistent with kernfs_create_file[_ns]().  This patch adds @mode
      parameter to kernfs_create_dir[_ns]() and update uses in sysfs
      accordingly.  Among others, this will be useful for implementations of
      the planned ->mkdir() method.
      
      This patch doesn't introduce any behavior differences.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      bb8b9d09
  2. 12 Dec, 2013 1 commit
    • Tejun Heo's avatar
      kernfs: s/sysfs/kernfs/ in constants · df23fc39
      Tejun Heo authored
      kernfs has just been separated out from sysfs and we're already in
      full conflict mode.  Nothing can make the situation any worse.  Let's
      take the chance to name things properly.
      
      This patch performs the following renames.
      
      * s/SYSFS_DIR/KERNFS_DIR/
      * s/SYSFS_KOBJ_ATTR/KERNFS_FILE/
      * s/SYSFS_KOBJ_LINK/KERNFS_LINK/
      * s/SYSFS_{TYPE_FLAGS}/KERNFS_{TYPE_FLAGS}/
      * s/SYSFS_FLAG_{FLAG}/KERNFS_{FLAG}/
      * s/sysfs_type()/kernfs_type()/
      * s/SD_DEACTIVATED_BIAS/KN_DEACTIVATED_BIAS/
      
      This patch is strictly rename only and doesn't introduce any
      functional difference.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      df23fc39
  3. 11 Dec, 2013 2 commits
    • Tejun Heo's avatar
      kernfs: drop s_ prefix from kernfs_node members · adc5e8b5
      Tejun Heo authored
      kernfs has just been separated out from sysfs and we're already in
      full conflict mode.  Nothing can make the situation any worse.  Let's
      take the chance to name things properly.
      
      s_ prefix for kernfs members is used inconsistently and a misnomer
      now.  It's not like kernfs_node is used widely across the kernel
      making the ability to grep for the members particularly useful.  Let's
      just drop the prefix.
      
      This patch is strictly rename only and doesn't introduce any
      functional difference.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      adc5e8b5
    • Tejun Heo's avatar
      kernfs: s/sysfs_dirent/kernfs_node/ and rename its friends accordingly · 324a56e1
      Tejun Heo authored
      kernfs has just been separated out from sysfs and we're already in
      full conflict mode.  Nothing can make the situation any worse.  Let's
      take the chance to name things properly.
      
      This patch performs the following renames.
      
      * s/sysfs_elem_dir/kernfs_elem_dir/
      * s/sysfs_elem_symlink/kernfs_elem_symlink/
      * s/sysfs_elem_attr/kernfs_elem_file/
      * s/sysfs_dirent/kernfs_node/
      * s/sd/kn/ in kernfs proper
      * s/parent_sd/parent/
      * s/target_sd/target/
      * s/dir_sd/parent/
      * s/to_sysfs_dirent()/rb_to_kn()/
      * misc renames of local vars when they conflict with the above
      
      Because md, mic and gpio dig into sysfs details, this patch ends up
      modifying them.  All are sysfs_dirent renames and trivial.  While we
      can avoid these by introducing a dummy wrapping struct sysfs_dirent
      around kernfs_node, given the limited usage outside kernfs and sysfs
      proper, I don't think such workaround is called for.
      
      This patch is strictly rename only and doesn't introduce any
      functional difference.
      
      - mic / gpio renames were missing.  Spotted by kbuild test robot.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Cc: Neil Brown <neilb@suse.de>
      Cc: Linus Walleij <linus.walleij@linaro.org>
      Cc: Ashutosh Dixit <ashutosh.dixit@intel.com>
      Cc: kbuild test robot <fengguang.wu@intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      324a56e1
  4. 30 Nov, 2013 7 commits
    • Tejun Heo's avatar
      sysfs, kernfs: introduce sysfs_root_sd · 061447a4
      Tejun Heo authored
      Currently, it's assumed that there's a single kernfs hierarchy in the
      system anchored at sysfs_root which is defined as a global struct.  To
      allow other users of kernfs, this will be made dynamic.  Introduce a
      new global variable sysfs_root_sd which points to &sysfs_root and
      convert all &sysfs_root users.
      
      This patch doesn't introduce any behavior difference.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      061447a4
    • Tejun Heo's avatar
      sysfs, kernfs: move dir core code to fs/kernfs/dir.c · fd7b9f7b
      Tejun Heo authored
      Move core dir code to fs/kernfs/dir.c.  fs/sysfs/dir.c now only
      contains sysfs_warn_dup() and sysfs wrappers around kernfs interfaces.
      The respective declarations in fs/sysfs/sysfs.h are moved to
      fs/kernfs/kernfs-internal.h.
      
      This is pure relocation.
      
      v2: sysfs_symlink_target_lock was mistakenly relocated to kernfs.  It
          should remain with sysfs.  Fixed.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      fd7b9f7b
    • Tejun Heo's avatar
      sysfs, kernfs: introduce kernfs[_find_and]_get() and kernfs_put() · ccf73cf3
      Tejun Heo authored
      Introduce kernfs interface for finding, getting and putting
      sysfs_dirents.
      
      * sysfs_find_dirent() is renamed to kernfs_find_ns() and lockdep
        assertion for sysfs_mutex is added.
      
      * sysfs_get_dirent_ns() is renamed to kernfs_find_and_get().
      
      * Macro inline dancing around __sysfs_get/put() are removed and
        kernfs_get/put() are made proper functions implemented in
        fs/sysfs/dir.c.
      
      While the conversions are mostly equivalent, there's one difference -
      kernfs_get() doesn't return the input param as its return value.  This
      change is intentional.  While passing through the input increases
      writability in some areas, it is unnecessary and has been shown to
      cause confusion regarding how the last ref is handled.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ccf73cf3
    • Tejun Heo's avatar
      sysfs, kernfs: revamp sysfs_dirent active_ref lockdep annotation · 517e64f5
      Tejun Heo authored
      Currently, sysfs_dirent active_ref lockdep annotation uses
      attribute->[s]key as the lockdep key, which forces
      kernfs_create_file_ns() to assume that sysfs_dirent->priv is pointing
      to a struct attribute which may not be true for non-sysfs users.  This
      patch restructures the lockdep annotation such that
      
      * kernfs_ops contains lockdep_key which is used by default for files
        created kernfs_create_file_ns().
      
      * kernfs_create_file_ns_key() is introduced which takes an extra @key
        argument.  The created file will use the specified key for
        active_ref lockdep annotation.  If NULL is specified, lockdep for
        the file is disabled.
      
      * sysfs_add_file_mode_ns() is updated to use
        kernfs_create_file_ns_key() with the appropriate key from the
        attribute or NULL if ignore_lockdep is set.
      
      This makes the lockdep annotation properly contained in kernfs while
      allowing sysfs to cleanly keep its current behavior.  This patch
      doesn't introduce any behavior differences.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      517e64f5
    • Tejun Heo's avatar
      sysfs, kernfs: remove sysfs_add_one() · 2d0cfbec
      Tejun Heo authored
      sysfs_add_one() is a wrapper around __sysfs_add_one() which prints out
      duplicate name warning if __sysfs_add_one() fails with -EEXIST.  The
      previous kernfs conversions moved all dup warnings to sysfs interface
      functions and sysfs_add_one() doesn't have any user left.
      
      Remove sysfs_add_one() and update __sysfs_add_one() to take its name.
      
      This patch doesn't make any functional changes.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      2d0cfbec
    • Tejun Heo's avatar
      sysfs, kernfs: introduce kernfs_create_dir[_ns]() · 93b2b8e4
      Tejun Heo authored
      Introduce kernfs interface to manipulate a directory which takes and
      returns sysfs_dirents.
      
      create_dir() is renamed to kernfs_create_dir_ns() and its argumantes
      and return value are updated.  create_dir() usages are replaced with
      kernfs_create_dir_ns() and sysfs_create_subdir() usages are replaced
      with kernfs_create_dir().  Dup warnings are handled explicitly by
      sysfs users of the kernfs interface.
      
      sysfs_enable_ns() is renamed to kernfs_enable_ns().
      
      This patch doesn't introduce any behavior changes.
      
      v2: Dummy implementation for !CONFIG_SYSFS updated to return -ENOSYS.
      
      v3: kernfs_enable_ns() added.
      
      v4: Refreshed on top of "sysfs: drop kobj_ns_type handling, take #2"
          so that this patch removes sysfs_enable_ns().
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      93b2b8e4
    • Tejun Heo's avatar
      sysfs, kernfs: replace sysfs_dirent->s_dir.kobj and ->s_attr.[bin_]attr with ->priv · 7c6e2d36
      Tejun Heo authored
      A directory sysfs_dirent points to the associated kobj.  A regular or
      bin file points to the associated [bin_]attribute.  This patch
      replaces sysfs_dirent->s_dir.kobj and ->s_attr.[bin_]attr with void *
      ->priv.
      
      This is to prepare for kernfs interface so that sysfs can specify the
      private data in the same way for directories and files.  This lower
      debuggability but not by much - the whole thing was overlaid in a
      union anyway.  If debuggability becomes an issue, we can later add
      ->priv accessors which explicitly check for the sysfs_dirent type and
      performs casting.
      
      This patch doesn't introduce any behavior difference.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7c6e2d36
  5. 27 Nov, 2013 4 commits
    • Tejun Heo's avatar
      sysfs, kernfs: introduce kernfs_rename[_ns]() · 890ece16
      Tejun Heo authored
      Introduce kernfs rename interface, krenfs_rename[_ns]().
      
      This is just rename of sysfs_rename().  No functional changes.
      Function comment is added to kernfs_rename_ns() and @new_parent_sd is
      renamed to @new_parent for consistency with other kernfs interfaces.
      
      v2: Dummy implementation for !CONFIG_SYSFS updated to return -ENOSYS.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      890ece16
    • Tejun Heo's avatar
      sysfs, kernfs: introduce kernfs_remove[_by_name[_ns]]() · 879f40d1
      Tejun Heo authored
      Introduce kernfs removal interfaces - kernfs_remove() and
      kernfs_remove_by_name[_ns]().
      
      These are just renames of sysfs_remove() and sysfs_hash_and_remove().
      No functional changes.
      
      v2: Dummy kernfs_remove_by_name_ns() for !CONFIG_SYSFS updated to
          return -ENOSYS instead of 0.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      879f40d1
    • Tejun Heo's avatar
      sysfs: make __sysfs_add_one() fail if the parent isn't a directory · ae2108ad
      Tejun Heo authored
      Currently the kobject based interface guarantees that a parent
      sysfs_dirent is always a directory; however, the planned kernfs
      interface will be directly based on sysfs_dirents and the caller may
      specify non-directory node as the parent.  Add an explicit check in
      __sysfs_add_one() so that such attempts fail with -EINVAL.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ae2108ad
    • Tejun Heo's avatar
      sysfs: drop kobj_ns_type handling, take #2 · c84a3b27
      Tejun Heo authored
      The way namespace tags are implemented in sysfs is more complicated
      than necessary.  As each tag is a pointer value and required to be
      non-NULL under a namespace enabled parent, there's no need to record
      separately what type each tag is.  If multiple namespace types are
      needed, which currently aren't, we can simply compare the tag to a set
      of allowed tags in the superblock assuming that the tags, being
      pointers, won't have the same value across multiple types.
      
      This patch rips out kobj_ns_type handling from sysfs.  sysfs now has
      an enable switch to turn on namespace under a node.  If enabled, all
      children are required to have non-NULL namespace tags and filtered
      against the super_block's tag.
      
      kobject namespace determination is now performed in
      lib/kobject.c::create_dir() making sysfs_read_ns_type() unnecessary.
      The sanity checks are also moved.  create_dir() is restructured to
      ease such addition.  This removes most kobject namespace knowledge
      from sysfs proper which will enable proper separation and layering of
      sysfs.
      
      This is the second try.  The first one was cb26a311 ("sysfs: drop
      kobj_ns_type handling") which tried to automatically enable namespace
      if there are children with non-NULL namespace tags; however, it was
      broken for symlinks as they should inherit the target's tag iff
      namespace is enabled in the parent.  This led to namespace filtering
      enabled incorrectly for wireless net class devices through phy80211
      symlinks and thus network configuration failure.  a1212d27
      ("Revert "sysfs: drop kobj_ns_type handling"") reverted the commit.
      
      This shouldn't introduce any behavior changes, for real.
      
      v2: Dummy implementation of sysfs_enable_ns() for !CONFIG_SYSFS was
          missing and caused build failure.  Reported by kbuild test robot.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Reported-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Cc: Eric W. Biederman <ebiederm@xmission.com>
      Cc: Kay Sievers <kay@vrfy.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: kbuild test robot <fengguang.wu@intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c84a3b27
  6. 07 Nov, 2013 1 commit
    • Linus Torvalds's avatar
      Revert "sysfs: drop kobj_ns_type handling" · a1212d27
      Linus Torvalds authored
      This reverts commit cb26a311.
      
      It mysteriously causes NetworkManager to not find the wireless device
      for me.  As far as I can tell, Tejun *meant* for this commit to not make
      any semantic changes, but there clearly are some.  So revert it, taking
      into account some of the calling convention changes that happened in
      this area in subsequent commits.
      
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a1212d27
  7. 01 Nov, 2013 1 commit
    • Tejun Heo's avatar
      sysfs: rename sysfs_assoc_lock and explain what it's about · 0cae60f9
      Tejun Heo authored
      sysfs_assoc_lock is an odd piece of locking.  In general, whoever owns
      a kobject is responsible for synchronizing sysfs operations and sysfs
      proper assumes that, for example, removal won't race with any other
      operation; however, this doesn't work for symlinking because an entity
      performing symlink doesn't usually own the target kobject and thus has
      no control over its removal.
      
      sysfs_assoc_lock synchronizes symlink operations against kobj->sd
      disassociation so that symlink code doesn't end up dereferencing
      already freed sysfs_dirent by racing with removal of the target
      kobject.
      
      This is quite obscure and the generic name of the lock and lack of
      comments make it difficult to understand its role.  Let's rename it to
      sysfs_symlink_target_lock and add comments explaining what's going on.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Reported-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0cae60f9
  8. 29 Oct, 2013 2 commits
  9. 14 Oct, 2013 1 commit
    • Tejun Heo's avatar
      sysfs: make sysfs_file_ops() follow ignore_lockdep flag · 785a162d
      Tejun Heo authored
      375b611e ("sysfs: remove sysfs_buffer->ops") introduced
      sysfs_file_ops() which determines the associated file operation of a
      given sysfs_dirent.  As file ops access should be protected by an
      active reference, the new function includes a lockdep assertion on the
      sysfs_dirent; unfortunately, I forgot to take attr->ignore_lockdep
      flag into account and the lockdep assertion trips spuriously for files
      which opt out from active reference lockdep checking.
      
      # cat /sys/devices/pci0000:00/0000:00:01.2/usb1/authorized
      
       ------------[ cut here ]------------
       WARNING: CPU: 1 PID: 540 at /work/os/work/fs/sysfs/file.c:79 sysfs_file_ops+0x4e/0x60()
       Modules linked in:
       CPU: 1 PID: 540 Comm: cat Not tainted 3.11.0-work+ #3
       Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
        0000000000000009 ffff880016205c08 ffffffff81ca0131 0000000000000000
        ffff880016205c40 ffffffff81096d0d ffff8800166cb898 ffff8800166f6f60
        ffffffff8125a220 ffff880011ab1ec0 ffff88000aff0c78 ffff880016205c50
       Call Trace:
        [<ffffffff81ca0131>] dump_stack+0x4e/0x82
        [<ffffffff81096d0d>] warn_slowpath_common+0x7d/0xa0
        [<ffffffff81096dea>] warn_slowpath_null+0x1a/0x20
        [<ffffffff8125994e>] sysfs_file_ops+0x4e/0x60
        [<ffffffff8125a274>] sysfs_open_file+0x54/0x300
        [<ffffffff811df612>] do_dentry_open.isra.17+0x182/0x280
        [<ffffffff811df820>] finish_open+0x30/0x40
        [<ffffffff811f0623>] do_last+0x503/0xd90
        [<ffffffff811f0f6b>] path_openat+0xbb/0x6d0
        [<ffffffff811f23ba>] do_filp_open+0x3a/0x90
        [<ffffffff811e09a9>] do_sys_open+0x129/0x220
        [<ffffffff811e0abe>] SyS_open+0x1e/0x20
        [<ffffffff81caf3c2>] system_call_fastpath+0x16/0x1b
       ---[ end trace aa48096b111dafdb ]---
      
      Rename fs/sysfs/dir.c::ignore_lockdep() to sysfs_ignore_lockdep() and
      move it to fs/sysfs/sysfs.h and make sysfs_file_ops() skip lockdep
      assertion if sysfs_ignore_lockdep() is true.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Reported-by: default avatarYinghai Lu <yinghai@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      785a162d
  10. 06 Oct, 2013 2 commits
    • Tejun Heo's avatar
      sysfs: merge regular and bin file handling · 3124eb16
      Tejun Heo authored
      With the previous changes, sysfs regular file code is ready to handle
      bin files too.  This patch makes bin files share the regular file
      path.
      
      * sysfs_create/remove_bin_file() are moved to fs/sysfs/file.c.
      
      * sysfs_init_inode() is updated to use the new sysfs_bin_operations
        instead of bin_fops for bin files.
      
      * fs/sysfs/bin.c and the related pieces are removed.
      
      This patch shouldn't introduce any behavior difference to bin file
      accesses.
      
      Overall, this unification reduces the amount of duplicate logic, makes
      behaviors more consistent and paves the road for building simpler and
      more versatile interface which will allow other subsystems to make use
      of sysfs for their pseudo filesystems.
      
      v2: Stale fs/sysfs/bin.c reference dropped from
          Documentation/DocBook/filesystems.tmpl.  Reported by kbuild test
          robot.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Cc: Kay Sievers <kay@vrfy.org>
      Cc: kbuild test robot <fengguang.wu@intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      3124eb16
    • Tejun Heo's avatar
      sysfs: copy bin mmap support from fs/sysfs/bin.c to fs/sysfs/file.c · 73d97146
      Tejun Heo authored
      sysfs bin file handling will be merged into the regular file support.
      This patch copies mmap support from bin so that fs/sysfs/file.c can
      handle mmapping bin files.
      
      The code is copied mostly verbatim with the following updates.
      
      * ->mmapped and ->vm_ops are added to sysfs_open_file and bin_buffer
        references are replaced with sysfs_open_file ones.
      
      * Symbols are prefixed with sysfs_.
      
      * sysfs_unmap_bin_file() grabs sysfs_open_dirent and traverses
        ->files.  Invocation of this function is added to
        sysfs_addrm_finish().
      
      * sysfs_bin_mmap() is added to sysfs_bin_operations.
      
      This is a preparation and the new mmap path isn't used yet.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      73d97146
  11. 03 Oct, 2013 4 commits
    • Tejun Heo's avatar
      sysfs: introduce [__]sysfs_remove() · 250f7c3f
      Tejun Heo authored
      Given a sysfs_dirent, there is no reason to have multiple versions of
      removal functions.  A function which removes the specified
      sysfs_dirent and its descendants is enough.
      
      This patch intorduces [__}sysfs_remove() which replaces all internal
      variations of removal functions.  This will be the only removal
      function in the planned new sysfs_dirent based interface.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      250f7c3f
    • Tejun Heo's avatar
      sysfs: make __sysfs_remove_dir() recursive · bcdde7e2
      Tejun Heo authored
      Currently, sysfs directory removal is inconsistent in that it would
      remove any files directly under it but wouldn't recurse into
      directories.  Thanks to group subdirectories, this doesn't even match
      with kobject boundaries.  sysfs is in the process of being separated
      out so that it can be used by multiple subsystems and we want to have
      a consistent behavior - either removal of a sysfs_dirent should remove
      every descendant entries or none instead of something inbetween.
      
      This patch implements proper recursive removal in
      __sysfs_remove_dir().  The function now walks its subtree in a
      post-order walk to remove all descendants.
      
      This is a behavior change but kobject / driver layer, which currently
      is the only consumer, has already been updated to handle duplicate
      removal attempts, so nothing should be broken after this change.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      bcdde7e2
    • Tejun Heo's avatar
      kobject: grab an extra reference on kobject->sd to allow duplicate deletes · 26ea12de
      Tejun Heo authored
      sysfs currently has a rather weird behavior regarding removals.  A
      directory removal would delete all files directly under it but
      wouldn't recurse into subdirectories, which, while a bit inconsistent,
      seems to make sense at the first glance as each directory is
      supposedly associated with a kobject and each kobject can take care of
      the directory deletion; however, this doesn't really hold as we have
      groups which can be directories without a kobject associated with it
      and require explicit deletions.
      
      We're in the process of separating out sysfs from kboject / driver
      core and want a consistent behavior.  A removal should delete either
      only the specified node or everything under it.  I think it is helpful
      to support recursive atomic removal and later patches will implement
      it.
      
      Such change means that a sysfs_dirent associated with kobject may be
      deleted before the kobject itself is removed if one of its ancestor
      gets removed before it.  As sysfs_remove_dir() puts the base ref, we
      may end up with dangling pointer on descendants.  This can be solved
      by holding an extra reference on the sd from kobject.
      
      Acquire an extra reference on the associated sysfs_dirent on directory
      creation and put it after removal.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      26ea12de
    • Tejun Heo's avatar
      sysfs: remove sysfs_addrm_cxt->parent_sd · d69ac5a0
      Tejun Heo authored
      sysfs_addrm_start/finish() enclose sysfs_dirent additions and
      deletions and sysfs_addrm_cxt is used to record information necessary
      to finish the operations.  Currently, sysfs_addrm_start() takes
      @parent_sd, records it in sysfs_addrm_cxt, and assumes that all
      operations in the block are performed under that @parent_sd.
      
      This assumption has been fine until now but we want to make some
      operations behave recursively and, while having @parent_sd recorded in
      sysfs_addrm_cxt doesn't necessarily prevents that, it becomes
      confusing.
      
      This patch removes sysfs_addrm_cxt->parent_sd and makes
      sysfs_add_one() take an explicit @parent_sd parameter.  Note that
      sysfs_remove_one() doesn't need the extra argument as its parent is
      always known from the target @sd.
      
      While at it, add __acquires/releases() notations to
      sysfs_addrm_start/finish() respectively.
      
      This patch doesn't make any functional difference.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d69ac5a0
  12. 26 Sep, 2013 5 commits
    • Tejun Heo's avatar
      sysfs: @name comes before @ns · cfec0bc8
      Tejun Heo authored
      Some internal sysfs functions which take explicit namespace argument
      are weird in that they place the optional @ns in front of @name which
      is contrary to the established convention.  This is confusing and
      error-prone especially as @ns and @name may be interchanged without
      causing compilation warning.
      
      Swap the positions of @name and @ns in the following internal
      functions.
      
       sysfs_find_dirent()
       sysfs_rename()
       sysfs_hash_and_remove()
       sysfs_name_hash()
       sysfs_name_compare()
       create_dir()
      
      This patch doesn't introduce any functional changes.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Cc: Eric W. Biederman <ebiederm@xmission.com>
      Cc: Kay Sievers <kay@vrfy.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      cfec0bc8
    • Tejun Heo's avatar
      sysfs: clean up sysfs_get_dirent() · 388975cc
      Tejun Heo authored
      The pre-existing sysfs interfaces which take explicit namespace
      argument are weird in that they place the optional @ns in front of
      @name which is contrary to the established convention.  For example,
      we end up forcing vast majority of sysfs_get_dirent() users to do
      sysfs_get_dirent(parent, NULL, name), which is silly and error-prone
      especially as @ns and @name may be interchanged without causing
      compilation warning.
      
      This renames sysfs_get_dirent() to sysfs_get_dirent_ns() and swap the
      positions of @name and @ns, and sysfs_get_dirent() is now a wrapper
      around sysfs_get_dirent_ns().  This makes confusions a lot less
      likely.
      
      There are other interfaces which take @ns before @name.  They'll be
      updated by following patches.
      
      This patch doesn't introduce any functional changes.
      
      v2: EXPORT_SYMBOL_GPL() wasn't updated leading to undefined symbol
          error on module builds.  Reported by build test robot.  Fixed.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Cc: Eric W. Biederman <ebiederm@xmission.com>
      Cc: Kay Sievers <kay@vrfy.org>
      Cc: Fengguang Wu <fengguang.wu@intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      388975cc
    • Tejun Heo's avatar
      sysfs: drop kobj_ns_type handling · cb26a311
      Tejun Heo authored
      The way namespace tags are implemented in sysfs is more complicated
      than necessary.  As each tag is a pointer value and required to be
      non-NULL under a namespace enabled parent, there's no need to record
      separately what type each tag is or where namespace is enabled.
      
      If multiple namespace types are needed, which currently aren't, we can
      simply compare the tag to a set of allowed tags in the superblock
      assuming that the tags, being pointers, won't have the same value
      across multiple types.  Also, whether to filter by namespace tag or
      not can be trivially determined by whether the node has any tagged
      children or not.
      
      This patch rips out kobj_ns_type handling from sysfs.  sysfs no longer
      cares whether specific type of namespace is enabled or not.  If a
      sysfs_dirent has a non-NULL tag, the parent is marked as needing
      namespace filtering and the value is tested against the allowed set of
      tags for the superblock (currently only one but increasing this number
      isn't difficult) and the sysfs_dirent is ignored if it doesn't match.
      
      This removes most kobject namespace knowledge from sysfs proper which
      will enable proper separation and layering of sysfs.  The namespace
      sanity checks in fs/sysfs/dir.c are replaced by the new sanity check
      in kobject_namespace().  As this is the only place ktype->namespace()
      is called for sysfs, this doesn't weaken the sanity check
      significantly.  I omitted converting the sanity check in
      sysfs_do_create_link_sd().  While the check can be shifted to upper
      layer, mistakes there are well contained and should be easily visible
      anyway.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Cc: Eric W. Biederman <ebiederm@xmission.com>
      Cc: Kay Sievers <kay@vrfy.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      cb26a311
    • Tejun Heo's avatar
      sysfs: remove ktype->namespace() invocations in directory code · e34ff490
      Tejun Heo authored
      For some unrecognizable reason, namespace information is communicated
      to sysfs through ktype->namespace() callback when there's *nothing*
      which needs the use of a callback.  The whole sequence of operations
      is completely synchronous and sysfs operations simply end up calling
      back into the layer which just invoked it in order to find out the
      namespace information, which is completely backwards, obfuscates
      what's going on and unnecessarily tangles two separate layers.
      
      This patch doesn't remove ktype->namespace() but shifts its handling
      to kobject layer.  We probably want to get rid of the callback in the
      long term.
      
      This patch adds an explicit param to sysfs_{create|rename|move}_dir()
      and renames them to sysfs_{create|rename|move}_dir_ns(), respectively.
      ktype->namespace() invocations are moved to the calling sites of the
      above functions.  A new helper kboject_namespace() is introduced which
      directly tests kobj_ns_type_operations->type which should give the
      same result as testing sysfs_fs_type(parent_sd) and returns @kobj's
      namespace tag as necessary.  kobject_namespace() is extern as it will
      be used from another file in the following patches.
      
      This patch should be an equivalent conversion without any functional
      difference.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Cc: Eric W. Biederman <ebiederm@xmission.com>
      Cc: Kay Sievers <kay@vrfy.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e34ff490
    • Tejun Heo's avatar
      sysfs: drop semicolon from to_sysfs_dirent() definition · bcac3769
      Tejun Heo authored
      The expansion of to_sysfs_dirent() contains an unncessary trailing
      semicolon making it impossible to use in the middle of statements.
      Drop it.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      bcac3769
  13. 05 Sep, 2013 1 commit
  14. 21 Aug, 2013 4 commits
  15. 29 Jun, 2013 1 commit
  16. 17 May, 2013 1 commit
  17. 05 Apr, 2013 1 commit
    • Ming Lei's avatar
      sysfs: check if one entry has been removed before freeing · bb2b0051
      Ming Lei authored
      It might be a kernel disaster if one sysfs entry is freed but
      still referenced by sysfs tree.
      
      Recently Dave and Sasha reported one use-after-free problem on
      sysfs entry, and the problem has been troubleshooted with help
      of debug message added in this patch.
      
      Given sysfs_get_dirent/sysfs_put are exported APIs, even inside
      sysfs they are called in many contexts(kobject/attribe add/delete,
      inode init/drop, dentry lookup/release, readdir, ...), it is healthful
      to check the removed flag before freeing one entry and dump message
      if it is freeing without being removed first.
      
      Cc: Dave Jones <davej@redhat.com>
      Cc: Sasha Levin <levinsasha928@gmail.com>
      Signed-off-by: default avatarMing Lei <ming.lei@canonical.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      bb2b0051
  18. 03 Apr, 2013 1 commit