1. 24 Jan, 2018 31 commits
  2. 19 Jan, 2018 6 commits
    • Amir Goldstein's avatar
      ovl: take mnt_want_write() for removing impure xattr · a5a927a7
      Amir Goldstein authored
      The optimization in ovl_cache_get_impure() that tries to remove an
      unneeded "impure" xattr needs to take mnt_want_write() on upper fs.
      
      Fixes: 4edb83bb ("ovl: constant d_ino for non-merge dirs")
      Cc: <stable@vger.kernel.org> #v4.14
      Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
      Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
      a5a927a7
    • Amir Goldstein's avatar
      ovl: take mnt_want_write() for work/index dir setup · 2ba9d57e
      Amir Goldstein authored
      There are several write operations on upper fs not covered by
      mnt_want_write():
      
      - test set/remove OPAQUE xattr
      - test create O_TMPFILE
      - set ORIGIN xattr in ovl_verify_origin()
      - cleanup of index entries in ovl_indexdir_cleanup()
      
      Some of these go way back, but this patch only applies over the
      v4.14 re-factoring of ovl_fill_super().
      
      Cc: <stable@vger.kernel.org> #v4.14
      Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
      Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
      2ba9d57e
    • Amir Goldstein's avatar
      f8167817
    • Amir Goldstein's avatar
      ovl: take lower dir inode mutex outside upper sb_writers lock · 6d0a8a90
      Amir Goldstein authored
      The functions ovl_lower_positive() and ovl_check_empty_dir() both take
      inode mutex on the real lower dir under ovl_want_write() which takes
      the upper_mnt sb_writers lock.
      
      While this is not a clear locking order or layering violation, it creates
      an undesired lock dependency between two unrelated layers for no good
      reason.
      
      This lock dependency materializes to a false(?) positive lockdep warning
      when calling rmdir() on a nested overlayfs, where both nested and
      underlying overlayfs both use the same fs type as upper layer.
      
      rmdir() on the nested overlayfs creates the lock chain:
        sb_writers of upper_mnt (e.g. tmpfs) in ovl_do_remove()
        ovl_i_mutex_dir_key[] of lower overlay dir in ovl_lower_positive()
      
      rmdir() on the underlying overlayfs creates the lock chain in
      reverse order:
        ovl_i_mutex_dir_key[] of lower overlay dir in vfs_rmdir()
        sb_writers of nested upper_mnt (e.g. tmpfs) in ovl_do_remove()
      
      To rid of the unneeded locking dependency, move both ovl_lower_positive()
      and ovl_check_empty_dir() to before ovl_want_write() in rmdir() and
      rename() implementation.
      
      This change spreads the pieces of ovl_check_empty_and_clear() directly
      inside the rmdir()/rename() implementations so the helper is no longer
      needed and removed.
      Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
      Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
      6d0a8a90
    • Amir Goldstein's avatar
      ovl: fix failure to fsync lower dir · d796e77f
      Amir Goldstein authored
      As a writable mount, it is not expected for overlayfs to return
      EINVAL/EROFS for fsync, even if dir/file is not changed.
      
      This commit fixes the case of fsync of directory, which is easier to
      address, because overlayfs already implements fsync file operation for
      directories.
      
      The problem reported by Raphael is that new PostgreSQL 10.0 with a
      database in overlayfs where lower layer in squashfs fails to start.
      The failure is due to fsync error, when PostgreSQL does fsync on all
      existing db directories on startup and a specific directory exists
      lower layer with no changes.
      Reported-by: default avatarRaphael Hertzog <raphael@ouaza.com>
      Cc: <stable@vger.kernel.org> # v3.18
      Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
      Tested-by: default avatarRaphaël Hertzog <hertzog@debian.org>
      Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
      d796e77f
    • Amir Goldstein's avatar
      ovl: hash directory inodes for fsnotify · 31747eda
      Amir Goldstein authored
      fsnotify pins a watched directory inode in cache, but if directory dentry
      is released, new lookup will allocate a new dentry and a new inode.
      Directory events will be notified on the new inode, while fsnotify listener
      is watching the old pinned inode.
      
      Hash all directory inodes to reuse the pinned inode on lookup. Pure upper
      dirs are hashes by real upper inode, merge and lower dirs are hashed by
      real lower inode.
      
      The reference to lower inode was being held by the lower dentry object
      in the overlay dentry (oe->lowerstack[0]). Releasing the overlay dentry
      may drop lower inode refcount to zero. Add a refcount on behalf of the
      overlay inode to prevent that.
      
      As a by-product, hashing directory inodes also detects multiple
      redirected dirs to the same lower dir and uncovered redirected dir
      target on and returns -ESTALE on lookup.
      
      The reported issue dates back to initial version of overlayfs, but this
      patch depends on ovl_inode code that was introduced in kernel v4.13.
      
      Cc: <stable@vger.kernel.org> #v4.13
      Reported-by: default avatarNiklas Cassel <niklas.cassel@axis.com>
      Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
      Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
      Tested-by: default avatarNiklas Cassel <niklas.cassel@axis.com>
      31747eda
  3. 14 Jan, 2018 3 commits
    • Linus Torvalds's avatar
      Linux 4.15-rc8 · a8750ddc
      Linus Torvalds authored
      a8750ddc
    • Linus Torvalds's avatar
      Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · aaae98a8
      Linus Torvalds authored
      Pull x86 fixlet from Thomas Gleixner.
      
      Remove a warning about lack of compiler support for retpoline that most
      people can't do anything about, so it just annoys them needlessly.
      
      * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86/retpoline: Remove compile time warning
      aaae98a8
    • Linus Torvalds's avatar
      Merge tag 'powerpc-4.15-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux · 6bb82119
      Linus Torvalds authored
      Pull powerpc fixes from Michael Ellerman:
       "One fix for an oops at boot if we take a hotplug interrupt before we
        are ready to handle it.
      
        The bulk is patches to implement mitigation for Meltdown, see the
        change logs for more details.
      
        Thanks to: Nicholas Piggin, Michael Neuling, Oliver O'Halloran, Jon
        Masters, Jose Ricardo Ziviani, David Gibson"
      
      * tag 'powerpc-4.15-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
        powerpc/powernv: Check device-tree for RFI flush settings
        powerpc/pseries: Query hypervisor for RFI flush settings
        powerpc/64s: Support disabling RFI flush with no_rfi_flush and nopti
        powerpc/64s: Add support for RFI flush of L1-D cache
        powerpc/64s: Convert slb_miss_common to use RFI_TO_USER/KERNEL
        powerpc/64: Convert fast_exception_return to use RFI_TO_USER/KERNEL
        powerpc/64: Convert the syscall exit path to use RFI_TO_USER/KERNEL
        powerpc/64s: Simple RFI macro conversions
        powerpc/64: Add macros for annotating the destination of rfid/hrfid
        powerpc/pseries: Add H_GET_CPU_CHARACTERISTICS flags & wrapper
        powerpc/pseries: Make RAS IRQ explicitly dependent on DLPAR WQ
      6bb82119