delalloc-debug

   1 ext4: add delalloc debugging
   2
   3 This adds a file in /proc/fs/ext4/<dev> which when opened for reading,
   4 will trigger debugging code that dumps a lot of information about
   5 inodes subject to delayed allocation to the console.
   6
   7 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
   8 ---
   9  fs/ext4/super.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
  10  1 file changed, 80 insertions(+), 1 deletion(-)
  11
  12 diff --git a/fs/ext4/super.c b/fs/ext4/super.c
  13 index 85b3dd6..ae13cd3 100644
  14 --- a/fs/ext4/super.c
  15 +++ b/fs/ext4/super.c
  16 @@ -790,6 +790,9 @@ static void ext4_put_super(struct super_block *sb)
  17
  18         if (sbi->s_proc) {
  19                 remove_proc_entry("options", sbi->s_proc);
  20 +#ifdef CONFIG_EXT4_DEBUG
  21 +               remove_proc_entry("delalloc_debug", sbi->s_proc);
  22 +#endif
  23                 remove_proc_entry(sb->s_id, ext4_proc_root);
  24         }
  25         kobject_del(&sbi->s_kobj);
  26 @@ -1832,6 +1835,74 @@ static const struct file_operations ext4_seq_options_fops = {
  27         .release = single_release,
  28  };
  29
  30 +#ifdef CONFIG_EXT4_DEBUG
  31 +static void print_inode_delalloc_info(struct inode *inode)
  32 +{
  33 +       if (!EXT4_I(inode)->i_reserved_data_blocks ||
  34 +           !EXT4_I(inode)->i_reserved_meta_blocks)
  35 +               return;
  36 +
  37 +       printk(KERN_DEBUG "ino %lu: %u %u\n", inode->i_ino,
  38 +              EXT4_I(inode)->i_reserved_data_blocks,
  39 +              EXT4_I(inode)->i_reserved_meta_blocks);
  40 +}
  41 +
  42 +static int debug_delalloc_show(struct seq_file *seq, void *offset)
  43 +{
  44 +       return 0;
  45 +}
  46 +
  47 +static int options_delalloc_debug_open_fs(struct inode *proc_inode,
  48 +                                         struct file *file)
  49 +{
  50 +       struct super_block *sb = PDE_DATA(proc_inode);
  51 +       struct ext4_sb_info *sbi = EXT4_SB(sb);
  52 +       struct inode *inode;
  53 +       extern spinlock_t inode_sb_list_lock;
  54 +
  55 +       printk(KERN_DEBUG "EXT4-fs debug delalloc of %s\n", sb->s_id);
  56 +       printk(KERN_DEBUG "EXT4-fs: dirty clusters %lld free clusters %lld\n",
  57 +              percpu_counter_sum(&sbi->s_dirtyclusters_counter),
  58 +              percpu_counter_sum(&sbi->s_freeclusters_counter));
  59 +
  60 +#ifndef MODULE
  61 +       spin_lock(&inode_sb_list_lock);
  62 +       if (!list_empty(&sb->s_bdi->wb.b_dirty)) {
  63 +               printk(KERN_DEBUG "s_bdi->wb.b_dirty list:\n");
  64 +               list_for_each_entry(inode, &sb->s_bdi->wb.b_dirty,
  65 +                                   i_wb_list) {
  66 +                       print_inode_delalloc_info(inode);
  67 +               }
  68 +       }
  69 +       if (!list_empty(&sb->s_bdi->wb.b_io)) {
  70 +               printk(KERN_DEBUG "s_bdi->wb.b_io list:\n");
  71 +               list_for_each_entry(inode, &sb->s_bdi->wb.b_io,
  72 +                                   i_wb_list) {
  73 +                       print_inode_delalloc_info(inode);
  74 +               }
  75 +       }
  76 +       if (!list_empty(&sb->s_bdi->wb.b_more_io)) {
  77 +               printk(KERN_DEBUG "s_bdi->wb.b_more_io list:\n");
  78 +               list_for_each_entry(inode, &sb->s_bdi->wb.b_more_io,
  79 +                                   i_wb_list) {
  80 +                       print_inode_delalloc_info(inode);
  81 +               }
  82 +       }
  83 +       spin_unlock(&inode_sb_list_lock);
  84 +       printk(KERN_DEBUG "ext4 debug delalloc done\n");
  85 +#endif
  86 +       return single_open(file, debug_delalloc_show, sb);
  87 +}
  88 +
  89 +static const struct file_operations ext4_seq_delalloc_debug_fops = {
  90 +       .owner = THIS_MODULE,
  91 +       .open = options_delalloc_debug_open_fs,
  92 +       .read = seq_read,
  93 +       .llseek = seq_lseek,
  94 +       .release = single_release,
  95 +};
  96 +#endif
  97 +
  98  static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
  99                             int read_only)
 100  {
 101 @@ -3764,9 +3835,14 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 102         if (ext4_proc_root)
 103                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
 104
 105 -       if (sbi->s_proc)
 106 +       if (sbi->s_proc) {
 107                 proc_create_data("options", S_IRUGO, sbi->s_proc,
 108                                  &ext4_seq_options_fops, sb);
 109 +#ifdef CONFIG_EXT4_DEBUG
 110 +               proc_create_data("delalloc_debug", S_IRUSR, sbi->s_proc,
 111 +                                &ext4_seq_delalloc_debug_fops, sb);
 112 +#endif
 113 +       }
 114
 115         bgl_lock_init(sbi->s_blockgroup_lock);
 116
 117 @@ -4149,6 +4225,9 @@ failed_mount:
 118                 crypto_free_shash(sbi->s_chksum_driver);
 119         if (sbi->s_proc) {
 120                 remove_proc_entry("options", sbi->s_proc);
 121 +#ifdef CONFIG_EXT4_DEBUG
 122 +               remove_proc_entry("delalloc_debug", sbi->s_proc);
 123 +#endif
 124                 remove_proc_entry(sb->s_id, ext4_proc_root);
 125         }
 126  #ifdef CONFIG_QUOTA