1. 30 Nov, 2013 13 commits
    • Tejun Heo's avatar
      sysfs, kernfs: add kernfs_ops->seq_{start|next|stop}() · d19b9846
      Tejun Heo authored
      
      
      kernfs_ops currently only supports single_open() behavior which is
      pretty restrictive.  Add optional callbacks ->seq_{start|next|stop}()
      which, when implemented, are invoked for seq_file traversal.  This
      allows full seq_file functionality for kernfs users.  This currently
      doesn't have any user and doesn't change any behavior.
      
      v2: Refreshed on top of the updated "sysfs, kernfs: prepare read path
          for kernfs".
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d19b9846
    • 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_file[_ns]() · 496f7394
      Tejun Heo authored
      
      
      Introduce kernfs interface to create a file which takes and returns
      sysfs_dirents.
      
      The actual file creation part is separated out from
      sysfs_add_file_mode_ns() into kernfs_create_file_ns().  The former now
      only decides the kernfs_ops to use and the file's size and invokes the
      latter.
      
      This patch doesn't introduce behavior changes.
      
      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>
      496f7394
    • Tejun Heo's avatar
      sysfs, kernfs: remove SYSFS_KOBJ_BIN_ATTR · a7dc66df
      Tejun Heo authored
      
      
      After kernfs_ops and sysfs_dirent->s_attr.size addition, the
      distinction between SYSFS_KOBJ_BIN_ATTR and SYSFS_KOBJ_ATTR is only
      necessary while creating files to decide which kernfs_ops to use.
      Afterwards, they behave exactly the same.
      
      This patch removes SYSFS_KOBJ_BIN_ATTR along with sysfs_is_bin().
      sysfs_add_file[_mode_ns]() are updated to take bool @is_bin instead of
      @type.
      
      This patch doesn't introduce any behavior changes.  This completely
      isolates the distinction between the two sysfs file types in the sysfs
      layer proper.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a7dc66df
    • Tejun Heo's avatar
      sysfs, kernfs: add sysfs_dirent->s_attr.size · 471bd7b7
      Tejun Heo authored
      
      
      sysfs sets the size of regular files unconditionally at PAGE_SIZE and
      takes the size of bin files from bin_attribute.  The latter is a
      pretty bad interface which forces bin_attribute users to create a
      separate copy of bin_attribute for each instance of the file -
      e.g. pci resource files.
      
      Add sysfs_dirent->s_attr.size so that the size can be specified
      separately.  This unifies inode init paths of ATTR and BIN_ATTR
      identical and allows for generic size handling for kernfs.
      
      Unfortunately, this grows the size of sysfs_dirent by sizeof(loff_t).
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      471bd7b7
    • Tejun Heo's avatar
      sysfs, kernfs: introduce kernfs_ops · f6acf8bb
      Tejun Heo authored
      
      
      We're in the process of separating out core sysfs functionality into
      kernfs which will deal with sysfs_dirents directly.  This patch
      introduces kernfs_ops which hosts methods kernfs users implement and
      updates fs/sysfs/file.c such that sysfs_kf_*() functions populate
      kernfs_ops and kernfs_file_*() functions call the matching entries
      from kernfs_ops.
      
      kernfs_ops contains the following groups of methods.
      
      * seq_show() - for kernfs files which use seq_file for reads.
      
      * read() - for direct read implementations.  Used iff seq_show() is
        not implemented.
      
      * write() - for writes.
      
      * mmap() - for mmaps.
      
      Notes:
      
      * sysfs_elem_attr->ops is added so that kernfs_ops can be accessed
        from sysfs_dirent.  kernfs_ops() helper is added to verify locking
        and access the field.
      
      * SYSFS_FLAG_HAS_(SEQ_SHOW|MMAP) added.  sd->s_attr->ops is accessible
        only while holding active_ref and there are cases where we want to
        take different actions depending on which ops are implemented.
        These two flags cache whether the two ops are implemented for those.
      
      * kernfs_file_*() no longer test sysfs type but chooses different
        behaviors depending on which methods in kernfs_ops are implemented.
        The conversions are trivial except for the open path.  As
        kernfs_file_open() now decides whether to allow read/write accesses
        depending on the kernfs_ops implemented, the presence of methods in
        kobjs and attribute_bin should be propagated to kernfs_ops.
        sysfs_add_file_mode_ns() is updated so that it propagates presence /
        absence of the callbacks through _empty, _ro, _wo, _rw kernfs_ops.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      f6acf8bb
    • Tejun Heo's avatar
      sysfs, kernfs: move sysfs_open_file to include/linux/kernfs.h · dd8a5b03
      Tejun Heo authored
      
      
      sysfs_open_file will be used as the primary handle for kernfs methods.
      Move its definition from fs/sysfs/file.c to include/linux/kernfs.h and
      mark the public and private fields.
      
      This is pure relocation.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      dd8a5b03
    • Tejun Heo's avatar
      sysfs, kernfs: prepare open, release, poll paths for kernfs · c6fb4495
      Tejun Heo authored
      
      
      We're in the process of separating out core sysfs functionality into
      kernfs which will deal with sysfs_dirents directly.  This patch
      prepares the rest - open, release and poll.  There isn't much to do.
      Just renaming is enough.  As sysfs_file_operations and
      sysfs_bin_operations are identical now, use the same file_operations
      for both - kernfs_file_operations.
      
      This patch doesn't introduce any behavior changes.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c6fb4495
    • Tejun Heo's avatar
      sysfs, kernfs: prepare mmap path for kernfs · fdbffaa4
      Tejun Heo authored
      
      
      We're in the process of separating out core sysfs functionality into
      kernfs which will deal with sysfs_dirents directly.  This patch
      rearranges mmap path so that the kernfs and sysfs parts are separate.
      
      sysfs_kf_bin_mmap() which handles the interaction with bin_attribute
      mmap method is factored out of sysfs_bin_mmap(), which is renamed to
      kernfs_file_mmap().  All vma ops are renamed accordingly.
      
      sysfs_bin_mmap() is updated such that it can be used for both file
      types.  This will eventually allow using the same file_operations for
      both file types, which is necessary to separate out kernfs.
      
      This patch doesn't introduce any behavior changes.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      fdbffaa4
    • Tejun Heo's avatar
      sysfs, kernfs: prepare write path for kernfs · 50b38ca0
      Tejun Heo authored
      
      
      We're in the process of separating out core sysfs functionality into
      kernfs which will deal with sysfs_dirents directly.  This patch
      rearranges write path so that the kernfs and sysfs parts are separate.
      
      kernfs_file_write() handles all boilerplate work including buffer
      management and locking and invokes sysfs_kf_write() or
      sysfs_kf_bin_write() depending on the file type which deals with the
      interaction with kobj store or bin_attribute write method.
      
      While this patch changes the order of some operations, it shouldn't
      change any visible behavior.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      50b38ca0
    • Tejun Heo's avatar
      sysfs, kernfs: prepare read path for kernfs · c2b19daf
      Tejun Heo authored
      
      
      We're in the process of separating out core sysfs functionality into
      kernfs which will deal with sysfs_dirents directly.  This patch
      rearranges read path so that the kernfs and sysfs parts are separate.
      
      * Regular file read path is refactored such that
        kernfs_seq_start/next/stop/show() handle all the boilerplate work
        including locking and updating event count for poll, while
        sysfs_kf_seq_show() deals with interaction with kobj show method.
      
      * Bin file read path is refactored such that kernfs_file_direct_read()
        handles all the boilerplate work including buffer management and
        locking, while sysfs_kf_bin_read() deals with interaction with
        bin_attribute read method.
      
      kernfs_file_read() is added.  It invokes either the seq_file or direct
      read path depending on the file type.  This will eventually allow
      using the same file_operations for both file types, which is necessary
      to separate out kernfs.
      
      While this patch changes the order of some operations, it shouldn't
      change any visible behavior.
      
      v2: Dropped unnecessary zeroing of @count from sysfs_kf_seq_show().
          Add comments explaining single_open() behavior.  Both suggested by
          Pavel.
      
      v3: seq_stop() is called even after seq_start() failed.
          kernfs_seq_start() updated so that it doesn't unlock
          sysfs_open_file->mutex on failure so that kernfs_seq_stop()
          doesn't try to unlock an already unlocked mutex.  Reported by
          Fengguang.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Fengguang Wu <fengguang.wu@intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c2b19daf
    • 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
  2. 29 Nov, 2013 1 commit
  3. 28 Nov, 2013 1 commit
  4. 27 Nov, 2013 8 commits
    • Tejun Heo's avatar
      sysfs, kernfs: introduce kernfs_setattr() · 5d60418e
      Tejun Heo authored
      
      
      Introduce kernfs setattr interface - kernfs_setattr().
      
      sysfs_sd_setattr() is renamed to __kernfs_setattr() and
      kernfs_setattr() is a simple wrapper around it with sysfs_mutex
      locking.  sysfs_chmod_file() is updated to get an explicit ref on
      kobj->sd and then invoke kernfs_setattr() so that it doesn't have to
      use internal interface.
      
      This patch doesn't introduce any behavior differences.
      
      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>
      5d60418e
    • 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_create_link() · 5d0e26bb
      Tejun Heo authored
      
      
      Separate out kernfs symlink interface - kernfs_create_link() - which
      takes and returns sysfs_dirents, from sysfs_do_create_link_sd().
      sysfs_do_create_link_sd() now just determines the parent and target
      sysfs_dirents and invokes the new interface and handles dup warning.
      
      This patch doesn't introduce behavior changes.
      
      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>
      5d0e26bb
    • 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, kernfs: add skeletons for kernfs · b8441ed2
      Tejun Heo authored
      
      
      Core sysfs implementation will be separated into kernfs so that it can
      be used by other non-kobject users.
      
      This patch creates fs/kernfs/ directory and makes boilerplate changes.
      kernfs interface will be directly based on sysfs_dirent and its
      forward declaration is moved to include/linux/kernfs.h which is
      included from include/linux/sysfs.h.  sysfs core implementation will
      be gradually separated out and moved to kernfs.
      
      This patch doesn't introduce any functional changes.
      
      v2: mount.c added.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Cc: linux-fsdevel@vger.kernel.org
      Cc: Christoph Hellwig <hch@infradead.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b8441ed2
    • 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
    • Greg Kroah-Hartman's avatar
      Revert "sysfs: handle duplicate removal attempts in sysfs_remove_group()" · 81440e73
      Greg Kroah-Hartman authored
      This reverts commit 54d71145
      
      .
      
      The root cause of these "inverted" sysfs removals have now been found,
      so there is no need for this patch.  Keep this functionality around so
      that this type of error doesn't show up in driver code again.
      
      Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
      Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
      Cc: Tejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      81440e73
  5. 25 Nov, 2013 1 commit
    • Steve French's avatar
      [CIFS] Do not use btrfs refcopy ioctl for SMB2 copy offload · f19e84df
      Steve French authored
      
      
      Change cifs.ko to using CIFS_IOCTL_COPYCHUNK instead
      of BTRFS_IOC_CLONE to avoid confusion about whether
      copy-on-write is required or optional for this operation.
      
      SMB2/SMB3 copyoffload had used the BTRFS_IOC_CLONE ioctl since
      they both speed up copy by offloading the copy rather than
      passing many read and write requests back and forth and both have
      identical syntax (passing file handles), but for SMB2/SMB3
      CopyChunk the server is not required to use copy-on-write
      to make a copy of the file (although some do), and Christoph
      has commented that since CopyChunk does not require
      copy-on-write we should not reuse BTRFS_IOC_CLONE.
      
      This patch renames the ioctl to use a cifs specific IOCTL
      CIFS_IOCTL_COPYCHUNK.  This ioctl is particularly important
      for SMB2/SMB3 since large file copy over the network otherwise
      can be very slow, and with this is often more than 100 times
      faster putting less load on server and client.
      
      Note that if a copy syscall is ever introduced, depending on
      its requirements/format it could end up using one of the other
      three methods that CIFS/SMB2/SMB3 can do for copy offload,
      but this method is particularly useful for file copy
      and broadly supported (not just by Samba server).
      Signed-off-by: default avatarSteve French <smfrench@gmail.com>
      Reviewed-by: default avatarJeff Layton <jlayton@redhat.com>
      Reviewed-by: default avatarDavid Disseldorp <ddiss@samba.org>
      f19e84df
  6. 23 Nov, 2013 8 commits
    • Li Wang's avatar
      ceph: allocate non-zero page to fscache in readpage() · ff638b7d
      Li Wang authored
      
      
      ceph_osdc_readpages() returns number of bytes read, currently,
      the code only allocate full-zero page into fscache, this patch
      fixes this.
      Signed-off-by: default avatarLi Wang <liwang@ubuntukylin.com>
      Reviewed-by: default avatarMilosz Tanski <milosz@adfin.com>
      Reviewed-by: default avatarSage Weil <sage@inktank.com>
      ff638b7d
    • Yan, Zheng's avatar
      ceph: wake up 'safe' waiters when unregistering request · fc55d2c9
      Yan, Zheng authored
      
      
      We also need to wake up 'safe' waiters if error occurs or request
      aborted. Otherwise sync(2)/fsync(2) may hang forever.
      Signed-off-by: default avatarYan, Zheng <zheng.z.yan@intel.com>
      Signed-off-by: default avatarSage Weil <sage@inktank.com>
      fc55d2c9
    • Yan, Zheng's avatar
      ceph: cleanup aborted requests when re-sending requests. · eb1b8af3
      Yan, Zheng authored
      
      
      Aborted requests usually get cleared when the reply is received.
      If MDS crashes, no reply will be received. So we need to cleanup
      aborted requests when re-sending requests.
      Signed-off-by: default avatarYan, Zheng <zheng.z.yan@intel.com>
      Reviewed-by: default avatarGreg Farnum <greg@inktank.com>
      Signed-off-by: default avatarSage Weil <sage@inktank.com>
      eb1b8af3
    • Yan, Zheng's avatar
      ceph: handle race between cap reconnect and cap release · 99a9c273
      Yan, Zheng authored
      
      
      When a cap get released while composing the cap reconnect message.
      We should skip queuing the release message if the cap hasn't been
      added to the cap reconnect message.
      Signed-off-by: default avatarYan, Zheng <zheng.z.yan@intel.com>
      Reviewed-by: default avatarSage Weil <sage@inktank.com>
      99a9c273
    • Yan, Zheng's avatar
      ceph: set caps count after composing cap reconnect message · 44c99757
      Yan, Zheng authored
      
      
      It's possible that some caps get released while composing the cap
      reconnect message.
      Signed-off-by: default avatarYan, Zheng <zheng.z.yan@intel.com>
      Reviewed-by: default avatarSage Weil <sage@inktank.com>
      44c99757
    • Yan, Zheng's avatar
      ceph: queue cap release in __ceph_remove_cap() · a096b09a
      Yan, Zheng authored
      
      
      call __queue_cap_release() in __ceph_remove_cap(), this avoids
      acquiring s_cap_lock twice.
      Signed-off-by: default avatarYan, Zheng <zheng.z.yan@intel.com>
      Reviewed-by: default avatarSage Weil <sage@inktank.com>
      a096b09a
    • Tejun Heo's avatar
      sysfs: use a separate locking class for open files depending on mmap · 027a485d
      Tejun Heo authored
      The following two commits implemented mmap support in the regular file
      path and merged bin file support into the regular path.
      
       73d97146 ("sysfs: copy bin mmap support from fs/sysfs/bin.c to fs/sysfs/file.c")
       3124eb16
      
       ("sysfs: merge regular and bin file handling")
      
      After the merge, the following commands trigger a spurious lockdep
      warning.  "test-mmap-read" simply mmaps the file and dumps the
      content.
      
        $ cat /sys/block/sda/trace/act_mask
        $ test-mmap-read /sys/devices/pci0000\:00/0000\:00\:03.0/resource0 4096
      
        ======================================================
        [ INFO: possible circular locking dependency detected ]
        3.12.0-work+ #378 Not tainted
        -------------------------------------------------------
        test-mmap-read/567 is trying to acquire lock:
         (&of->mutex){+.+.+.}, at: [<ffffffff8120a8df>] sysfs_bin_mmap+0x4f/0x120
      
        but task is already holding lock:
         (&mm->mmap_sem){++++++}, at: [<ffffffff8114b399>] vm_mmap_pgoff+0x49/0xa0
      
        which lock already depends on the new lock.
      
        the existing dependency chain (in reverse order) is:
      
        -> #3 (&mm->mmap_sem){++++++}:
        ...
        -> #2 (sr_mutex){+.+.+.}:
        ...
        -> #1 (&bdev->bd_mutex){+.+.+.}:
        ...
        -> #0 (&of->mutex){+.+.+.}:
        ...
      
        other info that might help us debug this:
      
        Chain exists of:
         &of->mutex --> sr_mutex --> &mm->mmap_sem
      
         Possible unsafe locking scenario:
      
      	 CPU0                    CPU1
      	 ----                    ----
          lock(&mm->mmap_sem);
      				 lock(sr_mutex);
      				 lock(&mm->mmap_sem);
          lock(&of->mutex);
      
         *** DEADLOCK ***
      
        1 lock held by test-mmap-read/567:
         #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff8114b399>] vm_mmap_pgoff+0x49/0xa0
      
        stack backtrace:
        CPU: 3 PID: 567 Comm: test-mmap-read Not tainted 3.12.0-work+ #378
        Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
         ffffffff81ed41a0 ffff880009441bc8 ffffffff81611ad2 ffffffff81eccb80
         ffff880009441c08 ffffffff8160f215 ffff880009441c60 ffff880009c75208
         0000000000000000 ffff880009c751e0 ffff880009c75208 ffff880009c74ac0
        Call Trace:
         [<ffffffff81611ad2>] dump_stack+0x4e/0x7a
         [<ffffffff8160f215>] print_circular_bug+0x2b0/0x2bf
         [<ffffffff8109ca0a>] __lock_acquire+0x1a3a/0x1e60
         [<ffffffff8109d6ba>] lock_acquire+0x9a/0x1d0
         [<ffffffff81615547>] mutex_lock_nested+0x67/0x3f0
         [<ffffffff8120a8df>] sysfs_bin_mmap+0x4f/0x120
         [<ffffffff8115d363>] mmap_region+0x3b3/0x5b0
         [<ffffffff8115d8ae>] do_mmap_pgoff+0x34e/0x3d0
         [<ffffffff8114b3ba>] vm_mmap_pgoff+0x6a/0xa0
         [<ffffffff8115be3e>] SyS_mmap_pgoff+0xbe/0x250
         [<ffffffff81008282>] SyS_mmap+0x22/0x30
         [<ffffffff8161a4d2>] system_call_fastpath+0x16/0x1b
      
      This happens because one file nests sr_mutex, which nests mm->mmap_sem
      under it, under of->mutex while mmap implementation naturally nests
      of->mutex under mm->mmap_sem.  The warning is false positive as
      of->mutex is per open-file and the two paths belong to two different
      files.  This warning didn't trigger before regular and bin file
      supports were merged because only bin file supported mmap and the
      other side of locking happened only on regular files which used
      equivalent but separate locking.
      
      It'd be best if we give separate locking classes per file but we can't
      easily do that.  Let's differentiate on ->mmap() for now.  Later we'll
      add explicit file operations struct and can add per-ops lockdep key
      there.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Reported-by: default avatarDave Jones <davej@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      027a485d
    • Mika Westerberg's avatar
      sysfs: handle duplicate removal attempts in sysfs_remove_group() · 54d71145
      Mika Westerberg authored
      Commit bcdde7e2
      
       (sysfs: make __sysfs_remove_dir() recursive) changed
      the behavior so that directory removals will be done recursively. This
      means that the sysfs group might already be removed if its parent directory
      has been removed.
      
      The current code outputs warnings similar to following log snippet when it
      detects that there is no group for the given kobject:
      
       WARNING: CPU: 0 PID: 4 at fs/sysfs/group.c:214 sysfs_remove_group+0xc6/0xd0()
       sysfs group ffffffff81c6f1e0 not found for kobject 'host7'
       Modules linked in:
       CPU: 0 PID: 4 Comm: kworker/0:0 Not tainted 3.12.0+ #13
       Hardware name:                  /D33217CK, BIOS GKPPT10H.86A.0042.2013.0422.1439 04/22/2013
       Workqueue: kacpi_hotplug acpi_hotplug_work_fn
        0000000000000009 ffff8801002459b0 ffffffff817daab1 ffff8801002459f8
        ffff8801002459e8 ffffffff810436b8 0000000000000000 ffffffff81c6f1e0
        ffff88006d440358 ffff88006d440188 ffff88006e8b4c28 ffff880100245a48
       Call Trace:
        [<ffffffff817daab1>] dump_stack+0x45/0x56
        [<ffffffff810436b8>] warn_slowpath_common+0x78/0xa0
        [<ffffffff81043727>] warn_slowpath_fmt+0x47/0x50
        [<ffffffff811ad319>] ? sysfs_get_dirent_ns+0x49/0x70
        [<ffffffff811ae526>] sysfs_remove_group+0xc6/0xd0
        [<ffffffff81432f7e>] dpm_sysfs_remove+0x3e/0x50
        [<ffffffff8142a0d0>] device_del+0x40/0x1b0
        [<ffffffff8142a24d>] device_unregister+0xd/0x20
        [<ffffffff8144131a>] scsi_remove_host+0xba/0x110
        [<ffffffff8145f526>] ata_host_detach+0xc6/0x100
        [<ffffffff8145f578>] ata_pci_remove_one+0x18/0x20
        [<ffffffff812e8f48>] pci_device_remove+0x28/0x60
        [<ffffffff8142d854>] __device_release_driver+0x64/0xd0
        [<ffffffff8142d8de>] device_release_driver+0x1e/0x30
        [<ffffffff8142d257>] bus_remove_device+0xf7/0x140
        [<ffffffff8142a1b1>] device_del+0x121/0x1b0
        [<ffffffff812e43d4>] pci_stop_bus_device+0x94/0xa0
        [<ffffffff812e437b>] pci_stop_bus_device+0x3b/0xa0
        [<ffffffff812e437b>] pci_stop_bus_device+0x3b/0xa0
        [<ffffffff812e44dd>] pci_stop_and_remove_bus_device+0xd/0x20
        [<ffffffff812fc743>] trim_stale_devices+0x73/0xe0
        [<ffffffff812fc78b>] trim_stale_devices+0xbb/0xe0
        [<ffffffff812fc78b>] trim_stale_devices+0xbb/0xe0
        [<ffffffff812fcb6e>] acpiphp_check_bridge+0x7e/0xd0
        [<ffffffff812fd90d>] hotplug_event+0xcd/0x160
        [<ffffffff812fd9c5>] hotplug_event_work+0x25/0x60
        [<ffffffff81316749>] acpi_hotplug_work_fn+0x17/0x22
        [<ffffffff8105cf3a>] process_one_work+0x17a/0x430
        [<ffffffff8105db29>] worker_thread+0x119/0x390
        [<ffffffff8105da10>] ? manage_workers.isra.25+0x2a0/0x2a0
        [<ffffffff81063a5d>] kthread+0xcd/0xf0
        [<ffffffff81063990>] ? kthread_create_on_node+0x180/0x180
        [<ffffffff817eb33c>] ret_from_fork+0x7c/0xb0
        [<ffffffff81063990>] ? kthread_create_on_node+0x180/0x180
      
      On this particular machine I see ~16 of these message during Thunderbolt
      hot-unplug.
      
      Fix this in similar way that was done for sysfs_remove_one() by checking
      if the parent directory has already been removed and bailing out early.
      Signed-off-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
      Acked-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      Acked-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      54d71145
  7. 22 Nov, 2013 1 commit
    • Junxiao Bi's avatar
      configfs: fix race between dentry put and lookup · 76ae281f
      Junxiao Bi authored
      
      
      A race window in configfs, it starts from one dentry is UNHASHED and end
      before configfs_d_iput is called.  In this window, if a lookup happen,
      since the original dentry was UNHASHED, so a new dentry will be
      allocated, and then in configfs_attach_attr(), sd->s_dentry will be
      updated to the new dentry.  Then in configfs_d_iput(),
      BUG_ON(sd->s_dentry != dentry) will be triggered and system panic.
      
      sys_open:                     sys_close:
       ...                           fput
                                      dput
                                       dentry_kill
                                        __d_drop <--- dentry unhashed here,
                                                 but sd->dentry still point
                                                 to this dentry.
      
       lookup_real
        configfs_lookup
         configfs_attach_attr---> update sd->s_dentry
                                  to new allocated dentry here.
      
                                         d_kill
                                           configfs_d_iput <--- BUG_ON(sd->s_dentry != dentry)
                                                           triggered here.
      
      To fix it, change configfs_d_iput to not update sd->s_dentry if
      sd->s_count > 2, that means there are another dentry is using the sd
      beside the one that is going to be put.  Use configfs_dirent_lock in
      configfs_attach_attr to sync with configfs_d_iput.
      
      With the following steps, you can reproduce the bug.
      
      1. enable ocfs2, this will mount configfs at /sys/kernel/config and
         fill configure in it.
      
      2. run the following script.
      	while [ 1 ]; do cat /sys/kernel/config/cluster/$your_cluster_name/idle_timeout_ms > /dev/null; done &
      	while [ 1 ]; do cat /sys/kernel/config/cluster/$your_cluster_name/idle_timeout_ms > /dev/null; done &
      Signed-off-by: default avatarJunxiao Bi <junxiao.bi@oracle.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      76ae281f
  8. 21 Nov, 2013 7 commits