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  1. Nov 15, 2010
  2. Nov 11, 2010
  3. Oct 22, 2010
  4. 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
  5. Aug 24, 2010
  6. Aug 10, 2010
    • Ming Lei's avatar
      USB: usbtest: support test device with only one iso-in or iso-out endpoint · 951fd8ee
      Ming Lei authored
      
      It is very common that one altsetting may include only one iso-in or iso-out
      single endpoint, especially for high bandwidth endpoint, so support it.
      
      Signed-off-by: default avatarMing Lei <tom.leiming@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      951fd8ee
    • Ming Lei's avatar
      USB: usbtest: avoid to free coherent buffer in atomic context · e10e1bec
      Ming Lei authored
      
      This patch fixes the warning below:
      [30753.755998] ------------[ cut here ]------------
      [30753.755998] WARNING: at /home/tom/git/linux-2.6/linux-2.6-next/arch/x86/include/asm/dma-mapping.h:155 hcd_buffer_free+0xb1/0xd4 [usbcore]()
      [30753.755998] Hardware name: 6475EK2
      [30753.755998] Modules linked in: uvcvideo ehci_hcd usbtest cdc_ether usbnet vfat fat usb_storage nfsd lockd nfs_acl auth_rpcgss exportfs mii tun videodev v4l1_compat v4l2_compat_ioctl32 fuse bridge stp llc sunrpc ipv6 cpufreq_ondemand acpi_cpufreq freq_table mperf kvm_intel kvm arc4 ecb ath5k usbhid mac80211 snd_hda_codec_conexant ch341 usbserial ath cfg80211 thinkpad_acpi snd_hda_intel pcspkr wmi hwmon yenta_socket iTCO_wdt iTCO_vendor_support i2c_i801 e1000e snd_hda_codec snd_hwdep snd_pcm snd_timer snd soundcore snd_page_alloc pata_acpi uhci_hcd ohci_hcd usbcore i915 drm_kms_helper drm i2c_algo_bit i2c_core video output [last unloaded: uvcvideo]
      [30753.755998] Pid: 0, comm: swapper Tainted: G        W   2.6.35-rc6-gkh-wl+ #49
      [30753.755998] Call Trace:
      [30753.755998]  <IRQ>  [<ffffffff8104478a>] warn_slowpath_common+0x80/0x98
      [30753.755998]  [<ffffffff810447b7>] warn_slowpath_null+0x15/0x17
      [30753.755998]  [<ffffffffa00ce02d>] hcd_buffer_free+0xb1/0xd4 [usbcore]
      [30753.755998]  [<ffffffffa00c1345>] usb_free_coherent+0x1c/0x1e [usbcore]
      [30753.755998]  [<ffffffffa00b13e4>] simple_free_urb+0x23/0x2f [usbtest]
      [30753.755998]  [<ffffffffa00b210b>] iso_callback+0xbb/0x10f [usbtest]
      [30753.755998]  [<ffffffffa00c7390>] usb_hcd_giveback_urb+0x8c/0xc0 [usbcore]
      [30753.755998]  [<ffffffffa0449b35>] ehci_urb_done+0x84/0x95 [ehci_hcd]
      [30753.755998]  [<ffffffffa044b5a5>] ehci_work+0x41a/0x7dd [ehci_hcd]
      [30753.755998]  [<ffffffffa044e298>] ehci_irq+0x33b/0x370 [ehci_hcd]
      [30753.755998]  [<ffffffff8100fb05>] ? sched_clock+0x9/0xd
      [30753.755998]  [<ffffffff8105e641>] ? sched_clock_local+0x1c/0x82
      [30753.755998]  [<ffffffff8105e76a>] ? sched_clock_cpu+0xc3/0xce
      [30753.755998]  [<ffffffff81067c7e>] ? trace_hardirqs_off+0xd/0xf
      [30753.755998]  [<ffffffff8105e7b8>] ? cpu_clock+0x43/0x5e
      [30753.755998]  [<ffffffffa00c6999>] usb_hcd_irq+0x45/0xa1 [usbcore]
      [30753.755998]  [<ffffffff81092e02>] handle_IRQ_event+0x20/0xa5
      [30753.755998]  [<ffffffff81094cea>] handle_fasteoi_irq+0x92/0xd2
      [30753.755998]  [<ffffffff8100c0ed>] handle_irq+0x1f/0x2a
      [30753.755998]  [<ffffffff8100b75d>] do_IRQ+0x57/0xbe
      [30753.755998]  [<ffffffff8136a693>] ret_from_intr+0x0/0x16
      [30753.755998]  <EOI>  [<ffffffff81223baa>] ? acpi_idle_enter_bm+0x231/0x269
      [30753.755998]  [<ffffffff81223ba3>] ? acpi_idle_enter_bm+0x22a/0x269
      [30753.755998]  [<ffffffff812c4b6b>] cpuidle_idle_call+0x99/0xce
      [30753.755998]  [<ffffffff81008dd5>] cpu_idle+0x61/0xaa
      [30753.755998]  [<ffffffff8136374b>] start_secondary+0x1c2/0x1c6
      [30753.755998] ---[ end trace 904cfaf7ab4cb1a2 ]---
      
      Signed-off-by: default avatarMing Lei <tom.leiming@gmail.com>
      Cc: stable <stable@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      e10e1bec
    • Joe Perches's avatar
      5bd6e8b3
    • Arnd Bergmann's avatar
      USB: autoconvert trivial BKL users to private mutex · 925ce689
      Arnd Bergmann authored
      
      All these files use the big kernel lock in a trivial
      way to serialize their private file operations,
      typically resulting from an earlier semi-automatic
      pushdown from VFS.
      
      None of these drivers appears to want to lock against
      other code, and they all use the BKL as the top-level
      lock in their file operations, meaning that there
      is no lock-order inversion problem.
      
      Consequently, we can remove the BKL completely,
      replacing it with a per-file mutex in every case.
      Using a scripted approach means we can avoid
      typos.
      
      file=$1
      name=$2
      if grep -q lock_kernel ${file} ; then
          if grep -q 'include.*linux.mutex.h' ${file} ; then
                  sed -i '/include.*<linux\/smp_lock.h>/d' ${file}
          else
                  sed -i 's/include.*<linux\/smp_lock.h>.*$/include <linux\/mutex.h>/g' ${file}
          fi
          sed -i ${file} \
              -e "/^#include.*linux.mutex.h/,$ {
                      1,/^\(static\|int\|long\)/ {
                           /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex);
      
      } }"  \
          -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \
          -e '/[      ]*cycle_kernel_lock();/d'
      else
          sed -i -e '/include.*\<smp_lock.h\>/d' ${file}  \
                      -e '/cycle_kernel_lock()/d'
      fi
      
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      925ce689
    • Andi Kleen's avatar
      USB-BKL: Convert usb_driver ioctl to unlocked_ioctl · c532b29a
      Andi Kleen authored
      
      And audit all the users. None needed the BKL.  That was easy
      because there was only very few around.
      
      Tested with allmodconfig build on x86-64
      
      Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      From: Andi Kleen <ak@linux.intel.com>
      c532b29a
    • Joe Perches's avatar
      drivers/usb: Remove unnecessary return's from void functions · 7f26b3a7
      Joe Perches authored
      Greg prefers this to go through the trivial tree.
      http://lkml.org/lkml/2010/6/24/1
      
      
      
      There are about 2500 void functions in drivers/usb
      Only a few used return; at end of function.
      
      Standardize them a bit.
      
      Moved a statement down a line in drivers/usb/host/u132-hcd.c
      
      Signed-off-by: default avatarJoe Perches <joe@perches.com>
      Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
      7f26b3a7
  7. Jul 26, 2010
  8. May 20, 2010
  9. Apr 22, 2010
  10. Mar 30, 2010
    • 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. Mar 16, 2010
  12. Mar 02, 2010
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