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  1. Oct 19, 2011
  2. Aug 28, 2011
    • Joe Perches's avatar
      caif: Remove OOM messages, use kzalloc · 7ac2ed0c
      Joe Perches authored
      
      Remove per site OOM messages because they duplicate
      the generic mm subsystem OOM message.
      
      Use kzalloc instead of kmalloc/memset
      when next to the OOM message removals.
      
      Reduces object size (allyesconfig ~2%)
      
      $ size -t drivers/net/caif/built-in.o.old net/caif/built-in.o.old
         text	   data	    bss	    dec	    hex	filename
        32297	    700	   8224	  41221	   a105	drivers/net/caif/built-in.o.old
        72159	   1317	  20552	  94028	  16f4c	net/caif/built-in.o.old
       104456	   2017	  28776	 135249	  21051	(TOTALS)
      $ size -t drivers/net/caif/built-in.o.new net/caif/built-in.o.new
         text	   data	    bss	    dec	    hex	filename
        31975	    700	   8184	  40859	   9f9b	drivers/net/caif/built-in.o.new
        70748	   1317	  20152	  92217	  16839	net/caif/built-in.o.new
       102723	   2017	  28336	 133076	  207d4	(TOTALS)
      
      Signed-off-by: default avatarJoe Perches <joe@perches.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      7ac2ed0c
  3. Jul 07, 2011
  4. Jun 29, 2011
  5. Jun 24, 2011
  6. Jun 21, 2011
  7. Jun 06, 2011
  8. Jun 03, 2011
    • Linus Torvalds's avatar
      Revert "tty: make receive_buf() return the amout of bytes received" · 55db4c64
      Linus Torvalds authored
      
      This reverts commit b1c43f82.
      
      It was broken in so many ways, and results in random odd pty issues.
      
      It re-introduced the buggy schedule_work() in flush_to_ldisc() that can
      cause endless work-loops (see commit a5660b41: "tty: fix endless
      work loop when the buffer fills up").
      
      It also used an "unsigned int" return value fo the ->receive_buf()
      function, but then made multiple functions return a negative error code,
      and didn't actually check for the error in the caller.
      
      And it didn't actually work at all.  BenH bisected down odd tty behavior
      to it:
        "It looks like the patch is causing some major malfunctions of the X
         server for me, possibly related to PTYs.  For example, cat'ing a
         large file in a gnome terminal hangs the kernel for -minutes- in a
         loop of what looks like flush_to_ldisc/workqueue code, (some ftrace
         data in the quoted bits further down).
      
         ...
      
         Some more data: It -looks- like what happens is that the
         flush_to_ldisc work queue entry constantly re-queues itself (because
         the PTY is full ?) and the workqueue thread will basically loop
         forver calling it without ever scheduling, thus starving the consumer
         process that could have emptied the PTY."
      
      which is pretty much exactly the problem we fixed in a5660b41.
      
      Milton Miller pointed out the 'unsigned int' issue.
      
      Reported-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      Reported-by: default avatarMilton Miller <miltonm@bga.com>
      Cc: Stefan Bigler <stefan.bigler@keymile.com>
      Cc: Toby Gray <toby.gray@realvnc.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@suse.de>
      Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      55db4c64
  9. Jun 01, 2011
  10. Apr 22, 2011
  11. Mar 31, 2011
  12. Mar 17, 2011
  13. Dec 22, 2010
  14. Dec 08, 2010
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  16. Nov 03, 2010
  17. Oct 27, 2010
  18. Oct 15, 2010
    • 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
  19. Aug 24, 2010
  20. Aug 10, 2010
  21. Jul 26, 2010
  22. Jul 12, 2010
  23. Jun 29, 2010
  24. Jun 20, 2010
  25. Jun 02, 2010
  26. Apr 28, 2010
  27. Apr 07, 2010
  28. Mar 30, 2010
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