1. 16 Jul, 2017 1 commit
    • Benjamin Coddington's avatar
      fs/locks: Remove fl_nspid and use fs-specific l_pid for remote locks · 9d5b86ac
      Benjamin Coddington authored
      Since commit c69899a1 "NFSv4: Update of VFS byte range lock must be
      atomic with the stateid update", NFSv4 has been inserting locks in rpciod
      worker context.  The result is that the file_lock's fl_nspid is the
      kworker's pid instead of the original userspace pid.
      
      The fl_nspid is only used to represent the namespaced virtual pid number
      when displaying locks or returning from F_GETLK.  There's no reason to set
      it for every inserted lock, since we can usually just look it up from
      fl_pid.  So, instead of looking up and holding struct pid for every lock,
      let's just look up the virtual pid number from fl_pid when it is needed.
      That means we can remove fl_nspid entirely.
      
      The translaton and presentation of fl_pid should handle the following four
      cases:
      
      1 - F_GETLK on a remote file with a remote lock:
          In this case, the filesystem should determine the l_pid to return here.
          Filesystems should indicate that the fl_pid represents a non-local pid
          value that should not be translated by returning an fl_pid <= 0.
      
      2 - F_GETLK on a local file with a remote lock:
          This should be the l_pid of the lock manager process, and translated.
      
      3 - F_GETLK on a remote file with a local lock, and
      4 - F_GETLK on a local file with a local lock:
          These should be the translated l_pid of the local locking process.
      
      Fuse was already doing the correct thing by translating the pid into the
      caller's namespace.  With this change we must update fuse to translate
      to init's pid namespace, so that the locks API can then translate from
      init's pid namespace into the pid namespace of the caller.
      
      With this change, the locks API will expect that if a filesystem returns
      a remote pid as opposed to a local pid for F_GETLK, that remote pid will
      be <= 0.  This signifies that the pid is remote, and the locks API will
      forego translating that pid into the pid namespace of the local calling
      process.
      
      Finally, we convert remote filesystems to present remote pids using
      negative numbers. Have lustre, 9p, ceph, cifs, and dlm negate the remote
      pid returned for F_GETLK lock requests.
      
      Since local pids will never be larger than PID_MAX_LIMIT (which is
      currently defined as <= 4 million), but pid_t is an unsigned int, we
      should have plenty of room to represent remote pids with negative
      numbers if we assume that remote pid numbers are similarly limited.
      
      If this is not the case, then we run the risk of having a remote pid
      returned for which there is also a corresponding local pid.  This is a
      problem we have now, but this patch should reduce the chances of that
      occurring, while also returning those remote pid numbers, for whatever
      that may be worth.
      Signed-off-by: default avatarBenjamin Coddington <bcodding@redhat.com>
      Signed-off-by: default avatarJeff Layton <jlayton@redhat.com>
      9d5b86ac
  2. 03 Nov, 2015 1 commit
  3. 22 Oct, 2015 1 commit
  4. 05 Aug, 2015 1 commit
  5. 09 Sep, 2014 1 commit
  6. 08 Apr, 2013 1 commit
    • David Teigland's avatar
      dlm: avoid unnecessary posix unlock · 90008318
      David Teigland authored
      When the kernel clears flocks/plocks during close, it calls posix
      unlock when there are flocks but no posix locks.  Without this
      patch, that unnecessary posix unlock is passed to userland
      (dlm_controld), across the cluster, and back to the kernel.
      This can create a lot of plock activity, even when no posix
      locks had been used.
      
      This patch copies the nfs approach, and skips the full posix
      unlock if there is no plock found during the vfs unlock phase.
      Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
      90008318
  7. 21 Jul, 2011 1 commit
    • J. Bruce Fields's avatar
      locks: rename lock-manager ops · 8fb47a4f
      J. Bruce Fields authored
      Both the filesystem and the lock manager can associate operations with a
      lock.  Confusingly, one of them (fl_release_private) actually has the
      same name in both operation structures.
      
      It would save some confusion to give the lock-manager ops different
      names.
      Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
      8fb47a4f
  8. 23 May, 2011 1 commit
    • David Teigland's avatar
      dlm: make plock operation killable · 901025d2
      David Teigland authored
      Allow processes blocked on plock requests to be interrupted
      when they are killed.  This leaves the problem of cleaning
      up the lock state in userspace.  This has three parts:
      
      1. Add a flag to unlock operations sent to userspace
      indicating the file is being closed.  Userspace will
      then look for and clear any waiting plock operations that
      were abandoned by an interrupted process.
      
      2. Queue an unlock-close operation (like in 1) to clean up
      userspace from an interrupted plock request.  This is needed
      because the vfs will not send a cleanup-unlock if it sees no
      locks on the file, which it won't if the interrupted operation
      was the only one.
      
      3. Do not use replies from userspace for unlock-close operations
      because they are unnecessary (they are just cleaning up for the
      process which did not make an unlock call).  This also simplifies
      the new unlock-close generated from point 2.
      Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
      901025d2
  9. 15 Oct, 2010 1 commit
    • Arnd Bergmann's avatar
      llseek: automatically add .llseek fop · 6038f373
      Arnd Bergmann authored
      All file_operations should get a .llseek operation so we can make
      nonseekable_open the default for future file operations without a
      .llseek pointer.
      
      The three cases that we can automatically detect are no_llseek, seq_lseek
      and default_llseek. For cases where we can we can automatically prove that
      the file offset is always ignored, we use noop_llseek, which maintains
      the current behavior of not returning an error from a seek.
      
      New drivers should normally not use noop_llseek but instead use no_llseek
      and call nonseekable_open at open time.  Existing drivers can be converted
      to do the same when the maintainer knows for certain that no user code
      relies on calling seek on the device file.
      
      The generated code is often incorrectly indented and right now contains
      comments that clarify for each added line why a specific variant was
      chosen. In the version that gets submitted upstream, the comments will
      be gone and I will manually fix the indentation, because there does not
      seem to be a way to do that using coccinelle.
      
      Some amount of new code is currently sitting in linux-next that should get
      the same modifications, which I will do at the end of the merge window.
      
      Many thanks to Julia Lawall for helping me learn to write a semantic
      patch that does all this.
      
      ===== begin semantic patch =====
      // This adds an llseek= method to all file operations,
      // as a preparation for making no_llseek the default.
      //
      // The rules are
      // - use no_llseek explicitly if we do nonseekable_open
      // - use seq_lseek for sequential files
      // - use default_llseek if we know we access f_pos
      // - use noop_llseek if we know we don't access f_pos,
      //   but we still want to allow users to call lseek
      //
      @ open1 exists @
      identifier nested_open;
      @@
      nested_open(...)
      {
      <+...
      nonseekable_open(...)
      ...+>
      }
      
      @ open exists@
      identifier open_f;
      identifier i, f;
      identifier open1.nested_open;
      @@
      int open_f(struct inode *i, struct file *f)
      {
      <+...
      (
      nonseekable_open(...)
      |
      nested_open(...)
      )
      ...+>
      }
      
      @ read disable optional_qualifier exists @
      identifier read_f;
      identifier f, p, s, off;
      type ssize_t, size_t, loff_t;
      expression E;
      identifier func;
      @@
      ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
      {
      <+...
      (
         *off = E
      |
         *off += E
      |
         func(..., off, ...)
      |
         E = *off
      )
      ...+>
      }
      
      @ read_no_fpos disable optional_qualifier exists @
      identifier read_f;
      identifier f, p, s, off;
      type ssize_t, size_t, loff_t;
      @@
      ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
      {
      ... when != off
      }
      
      @ write @
      identifier write_f;
      identifier f, p, s, off;
      type ssize_t, size_t, loff_t;
      expression E;
      identifier func;
      @@
      ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
      {
      <+...
      (
        *off = E
      |
        *off += E
      |
        func(..., off, ...)
      |
        E = *off
      )
      ...+>
      }
      
      @ write_no_fpos @
      identifier write_f;
      identifier f, p, s, off;
      type ssize_t, size_t, loff_t;
      @@
      ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
      {
      ... when != off
      }
      
      @ fops0 @
      identifier fops;
      @@
      struct file_operations fops = {
       ...
      };
      
      @ has_llseek depends on fops0 @
      identifier fops0.fops;
      identifier llseek_f;
      @@
      struct file_operations fops = {
      ...
       .llseek = llseek_f,
      ...
      };
      
      @ has_read depends on fops0 @
      identifier fops0.fops;
      identifier read_f;
      @@
      struct file_operations fops = {
      ...
       .read = read_f,
      ...
      };
      
      @ has_write depends on fops0 @
      identifier fops0.fops;
      identifier write_f;
      @@
      struct file_operations fops = {
      ...
       .write = write_f,
      ...
      };
      
      @ has_open depends on fops0 @
      identifier fops0.fops;
      identifier open_f;
      @@
      struct file_operations fops = {
      ...
       .open = open_f,
      ...
      };
      
      // use no_llseek if we call nonseekable_open
      ////////////////////////////////////////////
      @ nonseekable1 depends on !has_llseek && has_open @
      identifier fops0.fops;
      identifier nso ~= "nonseekable_open";
      @@
      struct file_operations fops = {
      ...  .open = nso, ...
      +.llseek = no_llseek, /* nonseekable */
      };
      
      @ nonseekable2 depends on !has_llseek @
      identifier fops0.fops;
      identifier open.open_f;
      @@
      struct file_operations fops = {
      ...  .open = open_f, ...
      +.llseek = no_llseek, /* open uses nonseekable */
      };
      
      // use seq_lseek for sequential files
      /////////////////////////////////////
      @ seq depends on !has_llseek @
      identifier fops0.fops;
      identifier sr ~= "seq_read";
      @@
      struct file_operations fops = {
      ...  .read = sr, ...
      +.llseek = seq_lseek, /* we have seq_read */
      };
      
      // use default_llseek if there is a readdir
      ///////////////////////////////////////////
      @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier readdir_e;
      @@
      // any other fop is used that changes pos
      struct file_operations fops = {
      ... .readdir = readdir_e, ...
      +.llseek = default_llseek, /* readdir is present */
      };
      
      // use default_llseek if at least one of read/write touches f_pos
      /////////////////////////////////////////////////////////////////
      @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier read.read_f;
      @@
      // read fops use offset
      struct file_operations fops = {
      ... .read = read_f, ...
      +.llseek = default_llseek, /* read accesses f_pos */
      };
      
      @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier write.write_f;
      @@
      // write fops use offset
      struct file_operations fops = {
      ... .write = write_f, ...
      +	.llseek = default_llseek, /* write accesses f_pos */
      };
      
      // Use noop_llseek if neither read nor write accesses f_pos
      ///////////////////////////////////////////////////////////
      
      @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier read_no_fpos.read_f;
      identifier write_no_fpos.write_f;
      @@
      // write fops use offset
      struct file_operations fops = {
      ...
       .write = write_f,
       .read = read_f,
      ...
      +.llseek = noop_llseek, /* read and write both use no f_pos */
      };
      
      @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier write_no_fpos.write_f;
      @@
      struct file_operations fops = {
      ... .write = write_f, ...
      +.llseek = noop_llseek, /* write uses no f_pos */
      };
      
      @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier read_no_fpos.read_f;
      @@
      struct file_operations fops = {
      ... .read = read_f, ...
      +.llseek = noop_llseek, /* read uses no f_pos */
      };
      
      @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      @@
      struct file_operations fops = {
      ...
      +.llseek = noop_llseek, /* no read or write fn */
      };
      ===== End semantic patch =====
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Cc: Julia Lawall <julia@diku.dk>
      Cc: Christoph Hellwig <hch@infradead.org>
      6038f373
  10. 30 Mar, 2010 1 commit
    • Tejun Heo's avatar
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo authored
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Guess-its-ok-by: default avatarChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  11. 04 Dec, 2009 1 commit
  12. 30 Nov, 2009 1 commit
    • David Teigland's avatar
      dlm: always use GFP_NOFS · 573c24c4
      David Teigland authored
      Replace all GFP_KERNEL and ls_allocation with GFP_NOFS.
      ls_allocation would be GFP_KERNEL for userland lockspaces
      and GFP_NOFS for file system lockspaces.
      
      It was discovered that any lockspaces on the system can
      affect all others by triggering memory reclaim in the
      file system which could in turn call back into the dlm
      to acquire locks, deadlocking dlm threads that were
      shared by all lockspaces, like dlm_recv.
      Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
      573c24c4
  13. 18 Jun, 2009 1 commit
    • David Teigland's avatar
      dlm: fix plock use-after-free · c78a87d0
      David Teigland authored
      Fix a regression from the original addition of nfs lock support
      586759f0.  When a synchronous
      (non-nfs) plock completes, the waiting thread will wake up and
      free the op struct.  This races with the user thread in
      dev_write() which goes on to read the op's callback field to
      check if the lock is async and needs a callback.  This check
      can happen on the freed op.  The fix is to note the callback
      value before the op can be freed.
      Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
      c78a87d0
  14. 21 Jan, 2009 2 commits
  15. 25 Jul, 2008 1 commit
    • Miklos Szeredi's avatar
      locks: add special return value for asynchronous locks · bde74e4b
      Miklos Szeredi authored
      Use a special error value FILE_LOCK_DEFERRED to mean that a locking
      operation returned asynchronously.  This is returned by
      
        posix_lock_file() for sleeping locks to mean that the lock has been
        queued on the block list, and will be woken up when it might become
        available and needs to be retried (either fl_lmops->fl_notify() is
        called or fl_wait is woken up).
      
        f_op->lock() to mean either the above, or that the filesystem will
        call back with fl_lmops->fl_grant() when the result of the locking
        operation is known.  The filesystem can do this for sleeping as well
        as non-sleeping locks.
      
      This is to make sure, that return values of -EAGAIN and -EINPROGRESS by
      filesystems are not mistaken to mean an asynchronous locking.
      
      This also makes error handling in fs/locks.c and lockd/svclock.c slightly
      cleaner.
      Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
      Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
      Cc: "J. Bruce Fields" <bfields@fieldses.org>
      Cc: Matthew Wilcox <matthew@wil.cx>
      Cc: David Teigland <teigland@redhat.com>
      Cc: Christoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      bde74e4b
  16. 19 May, 2008 1 commit
  17. 21 Apr, 2008 1 commit
  18. 25 Jan, 2008 1 commit
  19. 10 Oct, 2007 1 commit
  20. 09 Jul, 2007 2 commits
  21. 07 May, 2007 1 commit
  22. 12 Feb, 2007 1 commit
  23. 04 Dec, 2006 1 commit
  24. 08 Sep, 2006 1 commit
  25. 01 Sep, 2006 1 commit
    • Steven Whitehouse's avatar
      [GFS2] Update copyright, tidy up incore.h · e9fc2aa0
      Steven Whitehouse authored
      As per comments from Jan Engelhardt <jengelh@linux01.gwdg.de> this
      updates the copyright message to say "version" in full rather than
      "v.2". Also incore.h has been updated to remove forward structure
      declarations which are not required.
      
      The gfs2_quota_lvb structure has now had endianess annotations added
      to it. Also quota.c has been updated so that we now store the
      lvb data locally in endian independant format to avoid needing
      a structure in host endianess too. As a result the endianess
      conversions are done as required at various points and thus the
      conversion routines in lvb.[ch] are no longer required. I've
      moved the one remaining constant in lvb.h thats used into lm.h
      and removed the unused lvb.[ch].
      
      I have not changed the HIF_ constants. That is left to a later patch
      which I hope will unify the gh_flags and gh_iflags fields of the
      struct gfs2_holder.
      
      Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
      Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
      e9fc2aa0
  26. 07 Aug, 2006 1 commit
  27. 31 Jul, 2006 1 commit
  28. 24 May, 2006 1 commit
  29. 25 Apr, 2006 1 commit
  30. 27 Feb, 2006 1 commit
  31. 17 Jan, 2006 1 commit