1. 28 3月, 2011 2 次提交
  2. 22 2月, 2011 3 次提交
  3. 18 2月, 2011 1 次提交
  4. 18 1月, 2011 8 次提交
  5. 14 1月, 2011 1 次提交
  6. 13 1月, 2011 1 次提交
  7. 07 1月, 2011 6 次提交
    • N
      fs: provide rcu-walk aware permission i_ops · b74c79e9
      Nick Piggin 提交于
      Signed-off-by: NNick Piggin <npiggin@kernel.dk>
      b74c79e9
    • N
      fs: rcu-walk aware d_revalidate method · 34286d66
      Nick Piggin 提交于
      Require filesystems be aware of .d_revalidate being called in rcu-walk
      mode (nd->flags & LOOKUP_RCU). For now do a simple push down, returning
      -ECHILD from all implementations.
      Signed-off-by: NNick Piggin <npiggin@kernel.dk>
      34286d66
    • N
      fs: dcache reduce branches in lookup path · fb045adb
      Nick Piggin 提交于
      Reduce some branches and memory accesses in dcache lookup by adding dentry
      flags to indicate common d_ops are set, rather than having to check them.
      This saves a pointer memory access (dentry->d_op) in common path lookup
      situations, and saves another pointer load and branch in cases where we
      have d_op but not the particular operation.
      
      Patched with:
      
      git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i
      Signed-off-by: NNick Piggin <npiggin@kernel.dk>
      fb045adb
    • N
      fs: icache RCU free inodes · fa0d7e3d
      Nick Piggin 提交于
      RCU free the struct inode. This will allow:
      
      - Subsequent store-free path walking patch. The inode must be consulted for
        permissions when walking, so an RCU inode reference is a must.
      - sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
        to take i_lock no longer need to take sb_inode_list_lock to walk the list in
        the first place. This will simplify and optimize locking.
      - Could remove some nested trylock loops in dcache code
      - Could potentially simplify things a bit in VM land. Do not need to take the
        page lock to follow page->mapping.
      
      The downsides of this is the performance cost of using RCU. In a simple
      creat/unlink microbenchmark, performance drops by about 10% due to inability to
      reuse cache-hot slab objects. As iterations increase and RCU freeing starts
      kicking over, this increases to about 20%.
      
      In cases where inode lifetimes are longer (ie. many inodes may be allocated
      during the average life span of a single inode), a lot of this cache reuse is
      not applicable, so the regression caused by this patch is smaller.
      
      The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
      however this adds some complexity to list walking and store-free path walking,
      so I prefer to implement this at a later date, if it is shown to be a win in
      real situations. I haven't found a regression in any non-micro benchmark so I
      doubt it will be a problem.
      Signed-off-by: NNick Piggin <npiggin@kernel.dk>
      fa0d7e3d
    • N
      fs: dcache scale dentry refcount · b7ab39f6
      Nick Piggin 提交于
      Make d_count non-atomic and protect it with d_lock. This allows us to ensure a
      0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when
      we start protecting many other dentry members with d_lock.
      Signed-off-by: NNick Piggin <npiggin@kernel.dk>
      b7ab39f6
    • N
      fs: change d_hash for rcu-walk · b1e6a015
      Nick Piggin 提交于
      Change d_hash so it may be called from lock-free RCU lookups. See similar
      patch for d_compare for details.
      
      For in-tree filesystems, this is just a mechanical change.
      Signed-off-by: NNick Piggin <npiggin@kernel.dk>
      b1e6a015
  8. 18 11月, 2010 1 次提交
  9. 29 10月, 2010 7 次提交
  10. 15 10月, 2010 1 次提交
    • A
      llseek: automatically add .llseek fop · 6038f373
      Arnd Bergmann 提交于
      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: NArnd Bergmann <arnd@arndb.de>
      Cc: Julia Lawall <julia@diku.dk>
      Cc: Christoph Hellwig <hch@infradead.org>
      6038f373
  11. 05 10月, 2010 2 次提交
    • A
      BKL: Remove BKL from ecryptfs · 18dfe89d
      Arnd Bergmann 提交于
      The BKL is only used in fill_super, which is protected by the superblocks
      s_umount rw_semaphorei, and in fasync, which does not do anything that
      could require the BKL. Therefore it is safe to remove the BKL entirely.
      Signed-off-by: NArnd Bergmann <arnd@arndb.de>
      Cc: Dustin Kirkland <kirkland@canonical.com>
      Cc: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
      Cc: ecryptfs-devel@lists.launchpad.net
      18dfe89d
    • J
      BKL: Explicitly add BKL around get_sb/fill_super · db719222
      Jan Blunck 提交于
      This patch is a preparation necessary to remove the BKL from do_new_mount().
      It explicitly adds calls to lock_kernel()/unlock_kernel() around
      get_sb/fill_super operations for filesystems that still uses the BKL.
      
      I've read through all the code formerly covered by the BKL inside
      do_kern_mount() and have satisfied myself that it doesn't need the BKL
      any more.
      
      do_kern_mount() is already called without the BKL when mounting the rootfs
      and in nfsctl. do_kern_mount() calls vfs_kern_mount(), which is called
      from various places without BKL: simple_pin_fs(), nfs_do_clone_mount()
      through nfs_follow_mountpoint(), afs_mntpt_do_automount() through
      afs_mntpt_follow_link(). Both later functions are actually the filesystems
      follow_link inode operation. vfs_kern_mount() is calling the specified
      get_sb function and lets the filesystem do its job by calling the given
      fill_super function.
      
      Therefore I think it is safe to push down the BKL from the VFS to the
      low-level filesystems get_sb/fill_super operation.
      
      [arnd: do not add the BKL to those file systems that already
             don't use it elsewhere]
      Signed-off-by: NJan Blunck <jblunck@infradead.org>
      Signed-off-by: NArnd Bergmann <arnd@arndb.de>
      Cc: Matthew Wilcox <matthew@wil.cx>
      Cc: Christoph Hellwig <hch@infradead.org>
      db719222
  12. 23 9月, 2010 1 次提交
  13. 27 8月, 2010 3 次提交
  14. 10 8月, 2010 3 次提交
    • C
      pass a struct path to vfs_statfs · ebabe9a9
      Christoph Hellwig 提交于
      We'll need the path to implement the flags field for statvfs support.
      We do have it available in all callers except:
      
       - ecryptfs_statfs.  This one doesn't actually need vfs_statfs but just
         needs to do a caller to the lower filesystem statfs method.
       - sys_ustat.  Add a non-exported statfs_by_dentry helper for it which
         doesn't won't be able to fill out the flags field later on.
      
      In addition rename the helpers for statfs vs fstatfs to do_*statfs instead
      of the misleading vfs prefix.
      Signed-off-by: NChristoph Hellwig <hch@lst.de>
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      ebabe9a9
    • A
      convert remaining ->clear_inode() to ->evict_inode() · b57922d9
      Al Viro 提交于
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      b57922d9
    • C
      check ATTR_SIZE contraints in inode_change_ok · 2c27c65e
      Christoph Hellwig 提交于
      Make sure we check the truncate constraints early on in ->setattr by adding
      those checks to inode_change_ok.  Also clean up and document inode_change_ok
      to make this obvious.
      
      As a fallout we don't have to call inode_newsize_ok from simple_setsize and
      simplify it down to a truncate_setsize which doesn't return an error.  This
      simplifies a lot of setattr implementations and means we use truncate_setsize
      almost everywhere.  Get rid of fat_setsize now that it's trivial and mark
      ext2_setsize static to make the calling convention obvious.
      
      Keep the inode_newsize_ok in vmtruncate for now as all callers need an
      audit for its removal anyway.
      
      Note: setattr code in ecryptfs doesn't call inode_change_ok at all and
      needs a deeper audit, but that is left for later.
      Signed-off-by: NChristoph Hellwig <hch@lst.de>
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      2c27c65e