1. 08 Apr, 2013 4 commits
    • Bob Peterson's avatar
      GFS2: Remove vestigial parameter ip from function rs_deltree · 20095218
      Bob Peterson authored
      The functions that delete block reservations from the rgrp block
      reservations rbtree no longer use the ip parameter. This patch
      eliminates the parameter.
      Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
      Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
    • Steven Whitehouse's avatar
      GFS2: Use gfs2_dinode_out() in the inode create path · 79ba7480
      Steven Whitehouse authored
      Over the previous two patches relating to inode creation, the
      content of init_dinode() has been looking more and more like
      gfs2_dinode_out(). This is not an accident! This patch replaces
      the parts of init_dinode() which are duplicated in gfs2_dinode_out()
      with a call to that function.
      Mostly that is straightforward, but there is one issue which needed
      to be resolved relating to the link count. The link count has to be
      set to zero in a certain error handling code path, which lands up
      calling iput(). This is now done specifically in that code path
      allowing the link count to be set earlier and written into the
      on disk inode by gfs2_dinode_put() in the normal way.
      Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
    • Steven Whitehouse's avatar
      GFS2: Remove gfs2_refresh_inode from inode creation path · 28fb3027
      Steven Whitehouse authored
      The original method for creating inodes used in GFS2 was to fill
      out a buffer, with all the information, and then to read that
      buffer into the in-core inode, using gfs2_refresh_inode()
      The problem with this approach is that all the inode's fields
      need to be calculated ahead of time, and were stored in various
      variables making the code rather complicated.
      The new approach is simply to allocate the in-core inode earlier
      and fill in as many fields as possible ahead of time. These can
      then be used to initilise the on disk representation. The
      code has been working towards the point where it is possible
      to remove gfs2_refresh_inode() because all the fields are
      correctly initialised ahead of time. We've now reached that
      milestone, and have reversed the order of setting up the in
      core and on disk inodes.
      Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
    • Steven Whitehouse's avatar
      GFS2: Clean up inode creation path · fd4b4e04
      Steven Whitehouse authored
      This patch cleans up the inode creation code path in GFS2. After the
      Orlov allocator was merged, a number of potential improvements are
      now possible, and this is a first set of these.
      The quota handling is now updated so that it matches the point in
      the code where the allocation takes place. This means that the one
      exception in gfs2_alloc_blocks relating to quota is now no longer
      required, and we can use the generic code everywhere.
      In addition the call to figure out whether we need to allocate any
      extra blocks in order to add a directory entry is moved higher up
      gfs2_create_inode. This means that if it returns an error, we
      can deal with that at a stage where it is easier to handle that case.
      The returned status cannot change during the function since we hold
      an exclusive lock on the directory.
      Two calls to gfs2_rindex_update have been changed to one, again at
      the top of gfs2_create_inode to simplify error handling.
      The time stamps are also now initialised earlier in the creation
      process, this is gradually moving towards being able to remove the
      call to gfs2_refresh_inode in gfs2_inode_create once we have all the
      fields covered.
      Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
  2. 05 Apr, 2013 1 commit
    • Bob Peterson's avatar
      GFS2: Issue discards in 512b sectors · b2c87cae
      Bob Peterson authored
      This patch changes GFS2's discard issuing code so that it calls
      function sb_issue_discard rather than blkdev_issue_discard. The
      code was calling blkdev_issue_discard and specifying the correct
      sector offset and sector size, but blkdev_issue_discard expects
      these values to be in terms of 512 byte sectors, even if the native
      sector size for the device is different. Calling sb_issue_discard
      with the BLOCK size instead ensures the correct block-to-512b-sector
      translation. I verified that "minlen" is specified in blocks, so
      comparing it to a number of blocks is correct.
      Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
      Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
  3. 04 Apr, 2013 4 commits
  4. 04 Mar, 2013 1 commit
    • Eric W. Biederman's avatar
      fs: Limit sys_mount to only request filesystem modules. · 7f78e035
      Eric W. Biederman authored
      Modify the request_module to prefix the file system type with "fs-"
      and add aliases to all of the filesystems that can be built as modules
      to match.
      A common practice is to build all of the kernel code and leave code
      that is not commonly needed as modules, with the result that many
      users are exposed to any bug anywhere in the kernel.
      Looking for filesystems with a fs- prefix limits the pool of possible
      modules that can be loaded by mount to just filesystems trivially
      making things safer with no real cost.
      Using aliases means user space can control the policy of which
      filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
      with blacklist and alias directives.  Allowing simple, safe,
      well understood work-arounds to known problematic software.
      This also addresses a rare but unfortunate problem where the filesystem
      name is not the same as it's module name and module auto-loading
      would not work.  While writing this patch I saw a handful of such
      cases.  The most significant being autofs that lives in the module
      This is relevant to user namespaces because we can reach the request
      module in get_fs_type() without having any special permissions, and
      people get uncomfortable when a user specified string (in this case
      the filesystem type) goes all of the way to request_module.
      After having looked at this issue I don't think there is any
      particular reason to perform any filtering or permission checks beyond
      making it clear in the module request that we want a filesystem
      module.  The common pattern in the kernel is to call request_module()
      without regards to the users permissions.  In general all a filesystem
      module does once loaded is call register_filesystem() and go to sleep.
      Which means there is not much attack surface exposed by loading a
      filesytem module unless the filesystem is mounted.  In a user
      namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
      which most filesystems do not set today.
      Acked-by: default avatarSerge Hallyn <serge.hallyn@canonical.com>
      Acked-by: default avatarKees Cook <keescook@chromium.org>
      Reported-by: default avatarKees Cook <keescook@google.com>
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
  5. 26 Feb, 2013 2 commits
  6. 23 Feb, 2013 1 commit
  7. 22 Feb, 2013 1 commit
    • Darrick J. Wong's avatar
      mm: only enforce stable page writes if the backing device requires it · 1d1d1a76
      Darrick J. Wong authored
      Create a helper function to check if a backing device requires stable
      page writes and, if so, performs the necessary wait.  Then, make it so
      that all points in the memory manager that handle making pages writable
      use the helper function.  This should provide stable page write support
      to most filesystems, while eliminating unnecessary waiting for devices
      that don't require the feature.
      Before this patchset, all filesystems would block, regardless of whether
      or not it was necessary.  ext3 would wait, but still generate occasional
      checksum errors.  The network filesystems were left to do their own
      thing, so they'd wait too.
      After this patchset, all the disk filesystems except ext3 and btrfs will
      wait only if the hardware requires it.  ext3 (if necessary) snapshots
      pages instead of blocking, and btrfs provides its own bdi so the mm will
      never wait.  Network filesystems haven't been touched, so either they
      provide their own stable page guarantees or they don't block at all.
      The blocking behavior is back to what it was before 3.0 if you don't
      have a disk requiring stable page writes.
      Here's the result of using dbench to test latency on ext2:
       Operation      Count    AvgLat    MaxLat
       WriteX        109347     0.028    59.817
       ReadX         347180     0.004     3.391
       Flush          15514    29.828   287.283
      Throughput 57.429 MB/sec  4 clients  4 procs  max_latency=287.290 ms
      3.8.0-rc3 + patches:
       WriteX        105556     0.029     4.273
       ReadX         335004     0.005     4.112
       Flush          14982    30.540   298.634
      Throughput 55.4496 MB/sec  4 clients  4 procs  max_latency=298.650 ms
      As you can see, the maximum write latency drops considerably with this
      patch enabled.  The other filesystems (ext3/ext4/xfs/btrfs) behave
      similarly, but see the cover letter for those results.
      Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
      Acked-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
      Reviewed-by: default avatarJan Kara <jack@suse.cz>
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Artem Bityutskiy <dedekind1@gmail.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Eric Van Hensbergen <ericvh@gmail.com>
      Cc: Ron Minnich <rminnich@sandia.gov>
      Cc: Latchesar Ionkov <lucho@ionkov.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
  8. 13 Feb, 2013 13 commits
  9. 01 Feb, 2013 2 commits
  10. 29 Jan, 2013 7 commits
    • Steven Whitehouse's avatar
      GFS2: Use ->writepages for ordered writes · 45138990
      Steven Whitehouse authored
      Instead of using a list of buffers to write ahead of the journal
      flush, this now uses a list of inodes and calls ->writepages
      via filemap_fdatawrite() in order to achieve the same thing. For
      most use cases this results in a shorter ordered write list,
      as well as much larger i/os being issued.
      The ordered write list is sorted by inode number before writing
      in order to retain the disk block ordering between inodes as
      per the previous code.
      The previous ordered write code used to conflict in its assumptions
      about how to write out the disk blocks with mpage_writepages()
      so that with this updated version we can also use mpage_writepages()
      for GFS2's ordered write, writepages implementation. So we will
      also send larger i/os from writeback too.
      Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
    • Steven Whitehouse's avatar
      GFS2: Clean up freeze code · d564053f
      Steven Whitehouse authored
      The freeze code has not been looked at a lot recently. Upstream has
      moved on, and this is an attempt to catch us back up again. There
      is a vfs level interface for the freeze code which can be called
      from our (obsolete, but kept for backward compatibility purposes)
      sysfs freeze interface. This means freezing this way vs. doing it
      from the ioctl should now work in identical fashion.
      As a result of this, the freeze function is only called once
      and we can drop our own special purpose code for counting the
      number of freezes.
      Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
    • Steven Whitehouse's avatar
      GFS2: Merge gfs2_attach_bufdata() into trans.c · c76c4d96
      Steven Whitehouse authored
      The locking in gfs2_attach_bufdata() was type specific (data/meta)
      which made the function rather confusing. This patch moves the core
      of gfs2_attach_bufdata() into trans.c renaming it gfs2_alloc_bufdata()
      and moving the locking into gfs2_trans_add_data()/gfs2_trans_add_meta()
      As a result all of the locking related to adding data and metadata to
      the journal is now in these two functions. This should help to clarify
      what is going on, and give us some opportunities to simplify in
      some cases.
      Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
    • Steven Whitehouse's avatar
      GFS2: Copy gfs2_trans_add_bh into new data/meta functions · 767f433f
      Steven Whitehouse authored
      This patch copies the body of gfs2_trans_add_bh into the two newly
      added gfs2_trans_add_data and gfs2_trans_add_meta functions. We can
      then move the .lo_add functions from lops.c into trans.c and call
      them directly.
      As a result of this, we no longer need to use the .lo_add functions
      at all, so that is removed from the log operations structure.
      Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
    • Steven Whitehouse's avatar
      GFS2: Split gfs2_trans_add_bh() into two · 350a9b0a
      Steven Whitehouse authored
      There is little common content in gfs2_trans_add_bh() between the data
      and meta classes by the time that the functions which it calls are
      taken into account. The intent here is to split this into two
      separate functions. Stage one is to introduce gfs2_trans_add_data()
      and gfs2_trans_add_meta() and update the callers accordingly.
      Later patches will then pull in the content of gfs2_trans_add_bh()
      and its dependent functions in order to clean up the code in this
      Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
    • Steven Whitehouse's avatar
      GFS2: Merge revoke adding functions · 75f2b879
      Steven Whitehouse authored
      This moves the lo_add function for revokes into trans.c, removing
      a function call and making the code easier to read.
      Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
    • Steven Whitehouse's avatar
      GFS2: Separate LRU scanning from shrinker · 2a005855
      Steven Whitehouse authored
      This breaks out the LRU scanning function from the shrinker in
      preparation for adding other callers to the LRU scanner.
      Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
  11. 28 Jan, 2013 1 commit
  12. 02 Jan, 2013 3 commits
    • Bob Peterson's avatar
      GFS2: Reset rd_last_alloc when it reaches the end of the rgrp · 13d2eb01
      Bob Peterson authored
      In function rg_mblk_search, it's searching for multiple blocks in
      a given state (e.g. "free"). If there's an active block reservation
      its goal is the next free block of that. If the resource group
      contains the dinode's goal block, that's used for the search. But
      if neither is the case, it uses the rgrp's last allocated block.
      That way, consecutive allocations appear after one another on media.
      The problem comes in when you hit the end of the rgrp; it would never
      start over and search from the beginning. This became a problem,
      since if you deleted all the files and data from the rgrp, it would
      never start over and find free blocks. So it had to keep searching
      further out on the media to allocate blocks. This patch resets the
      rd_last_alloc after it does an unsuccessful search at the end of
      the rgrp.
      Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
      Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
    • Bob Peterson's avatar
      GFS2: Stop looking for free blocks at end of rgrp · 15bd50ad
      Bob Peterson authored
      This patch adds a return code check after calling function
      gfs2_rbm_from_block while determining the free extent size.
      That way, when the end of an rgrp is reached, it won't try
      to process unaligned blocks after the end.
      Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
      Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
    • Abhijith Das's avatar
      GFS2: Fix race in gfs2_rs_alloc · f1213cac
      Abhijith Das authored
      QE aio tests uncovered a race condition in gfs2_rs_alloc where it's possible
      to come out of the function with a valid ip->i_res allocation but it gets
      freed before use resulting in a NULL ptr dereference.
      This patch envelopes the initial short-circuit check for non-NULL ip->i_res
      into the mutex lock. With this patch, I was able to successfully run the
      reproducer test multiple times.
      Resolves: rhbz#878476
      Signed-off-by: default avatarAbhi Das <adas@redhat.com>
      Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>