src/patches/suse-2.6.27.39/patches.suse/ocfs2-track-local-alloc-state-via-debugfs.patch

   1 From: Mark Fasheh <mfasheh@suse.com>
   2 Subject: ocfs2: track local alloc state via debugfs
   3 Patch-mainline: 2.6.28
   4
   5 A per-mount debugfs file, "local_alloc" is created which when read will
   6 expose live state of the nodes local alloc file. Performance impact is
   7 minimal, only a bit of memory overhead per mount point. Still, the code is
   8 hidden behind CONFIG_OCFS2_FS_STATS. This feature will help us debug
   9 local alloc performance problems on a live system.
  10
  11 Signed-off-by: Mark Fasheh <mfasheh@suse.com>
  12 ---
  13  fs/ocfs2/localalloc.c |   87 ++++++++++++++++++++++++++++++++++++++++++++++++++
  14  fs/ocfs2/ocfs2.h      |    5 ++
  15  2 files changed, 92 insertions(+)
  16
  17 --- a/fs/ocfs2/localalloc.c
  18 +++ b/fs/ocfs2/localalloc.c
  19 @@ -28,6 +28,7 @@
  20  #include <linux/slab.h>
  21  #include <linux/highmem.h>
  22  #include <linux/bitops.h>
  23 +#include <linux/debugfs.h>
  24
  25  #define MLOG_MASK_PREFIX ML_DISK_ALLOC
  26  #include <cluster/masklog.h>
  27 @@ -73,6 +74,85 @@ static int ocfs2_local_alloc_new_window(
  28  static int ocfs2_local_alloc_slide_window(struct ocfs2_super *osb,
  29                                           struct inode *local_alloc_inode);
  30
  31 +#ifdef CONFIG_OCFS2_FS_STATS
  32 +
  33 +DEFINE_MUTEX(la_debug_mutex);
  34 +
  35 +static int ocfs2_la_debug_open(struct inode *inode, struct file *file)
  36 +{
  37 +       file->private_data = inode->i_private;
  38 +       return 0;
  39 +}
  40 +
  41 +#define LA_DEBUG_BUF_SZ        PAGE_CACHE_SIZE
  42 +#define LA_DEBUG_VER   1
  43 +static ssize_t ocfs2_la_debug_read(struct file *file, char __user *userbuf,
  44 +                                  size_t count, loff_t *ppos)
  45 +{
  46 +       struct ocfs2_super *osb = file->private_data;
  47 +       int written, ret;
  48 +       char *buf = osb->local_alloc_debug_buf;
  49 +
  50 +       mutex_lock(&la_debug_mutex);
  51 +       memset(buf, 0, LA_DEBUG_BUF_SZ);
  52 +
  53 +       written = snprintf(buf, LA_DEBUG_BUF_SZ,
  54 +                          "0x%x\t0x%llx\t%u\t%u\t0x%x\n",
  55 +                          LA_DEBUG_VER,
  56 +                          (unsigned long long)osb->la_last_gd,
  57 +                          osb->local_alloc_default_bits,
  58 +                          osb->local_alloc_bits, osb->local_alloc_state);
  59 +
  60 +       ret = simple_read_from_buffer(userbuf, count, ppos, buf, written);
  61 +
  62 +       mutex_unlock(&la_debug_mutex);
  63 +       return ret;
  64 +}
  65 +
  66 +static const struct file_operations ocfs2_la_debug_fops = {
  67 +       .open =         ocfs2_la_debug_open,
  68 +       .read =         ocfs2_la_debug_read,
  69 +};
  70 +
  71 +static void ocfs2_init_la_debug(struct ocfs2_super *osb)
  72 +{
  73 +       osb->local_alloc_debug_buf = kmalloc(LA_DEBUG_BUF_SZ, GFP_NOFS);
  74 +       if (!osb->local_alloc_debug_buf)
  75 +               return;
  76 +
  77 +       osb->local_alloc_debug = debugfs_create_file("local_alloc_stats",
  78 +                                                    S_IFREG|S_IRUSR,
  79 +                                                    osb->osb_debug_root,
  80 +                                                    osb,
  81 +                                                    &ocfs2_la_debug_fops);
  82 +       if (!osb->local_alloc_debug) {
  83 +               kfree(osb->local_alloc_debug_buf);
  84 +               osb->local_alloc_debug_buf = NULL;
  85 +       }
  86 +}
  87 +
  88 +static void ocfs2_shutdown_la_debug(struct ocfs2_super *osb)
  89 +{
  90 +       if (osb->local_alloc_debug)
  91 +               debugfs_remove(osb->local_alloc_debug);
  92 +
  93 +       if (osb->local_alloc_debug_buf)
  94 +               kfree(osb->local_alloc_debug_buf);
  95 +
  96 +       osb->local_alloc_debug_buf = NULL;
  97 +       osb->local_alloc_debug = NULL;
  98 +}
  99 +#else  /* CONFIG_OCFS2_FS_STATS */
 100 +static void ocfs2_init_la_debug(struct ocfs2_super *osb)
 101 +{
 102 +       return;
 103 +}
 104 +static void ocfs2_shutdown_la_debug(struct ocfs2_super *osb)
 105 +{
 106 +       return;
 107 +}
 108 +#endif
 109 +
 110  static inline int ocfs2_la_state_enabled(struct ocfs2_super *osb)
 111  {
 112         return (osb->local_alloc_state == OCFS2_LA_THROTTLED ||
 113 @@ -146,6 +226,8 @@ int ocfs2_load_local_alloc(struct ocfs2_
 114
 115         mlog_entry_void();
 116
 117 +       ocfs2_init_la_debug(osb);
 118 +
 119         if (osb->local_alloc_bits == 0)
 120                 goto bail;
 121
 122 @@ -218,6 +300,9 @@ bail:
 123         if (inode)
 124                 iput(inode);
 125
 126 +       if (status < 0)
 127 +               ocfs2_shutdown_la_debug(osb);
 128 +
 129         mlog(0, "Local alloc window bits = %d\n", osb->local_alloc_bits);
 130
 131         mlog_exit(status);
 132 @@ -247,6 +332,8 @@ void ocfs2_shutdown_local_alloc(struct o
 133         cancel_delayed_work(&osb->la_enable_wq);
 134         flush_workqueue(ocfs2_wq);
 135
 136 +       ocfs2_shutdown_la_debug(osb);
 137 +
 138         if (osb->local_alloc_state == OCFS2_LA_UNUSED)
 139                 goto out;
 140
 141 --- a/fs/ocfs2/ocfs2.h
 142 +++ b/fs/ocfs2/ocfs2.h
 143 @@ -281,6 +281,11 @@ struct ocfs2_super
 144
 145         u64 la_last_gd;
 146
 147 +#ifdef CONFIG_OCFS2_FS_STATS
 148 +       struct dentry *local_alloc_debug;
 149 +       char *local_alloc_debug_buf;
 150 +#endif
 151 +
 152         /* Next two fields are for local node slot recovery during
 153          * mount. */
 154         int dirty;