add-squelch-errors-support

   1 ext4: add option for squelching ext4 errors to prevent dmesg from filling up
   2
   3 Only print one error per inode; this is enough to know that something
   4 is wrong with an inode, without filling dmesg by spamming the system
   5 with messages over and over again.
   6
   7 This is enabled via sysfs option, which is currently off by default.
   8 Some environments may want to turn this on by default.  Eventually we
   9 may want to make this be something which is tunable by a superblock
  10 flag, perhaps.
  11
  12 Addresses-Google-Bug: #2507977
  13
  14 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
  15 ---
  16  fs/ext4/ext4.h  | 2 ++
  17  fs/ext4/super.c | 2 ++
  18  2 files changed, 4 insertions(+)
  19
  20 diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
  21 index 953f504..d0be35a 100644
  22 --- a/fs/ext4/ext4.h
  23 +++ b/fs/ext4/ext4.h
  24 @@ -1158,6 +1158,7 @@ struct ext4_super_block {
  25   */
  26  #define EXT4_MF_MNTDIR_SAMPLED 0x0001
  27  #define EXT4_MF_FS_ABORTED     0x0002  /* Fatal error detected */
  28 +#define EXT4_MF_FS_SQUELCH     0x0004  /* Squelch file system errors */
  29
  30  /*
  31   * fourth extended-fs super-block data in memory
  32 @@ -1389,6 +1390,7 @@ enum {
  33         EXT4_STATE_MAY_INLINE_DATA,     /* may have in-inode data */
  34         EXT4_STATE_ORDERED_MODE,        /* data=ordered mode */
  35         EXT4_STATE_EXT_PRECACHED,       /* extents have been precached */
  36 +       EXT4_STATE_ERR_SQUELCHED,       /* squeched error */
  37  };
  38
  39  #define EXT4_INODE_BIT_FNS(name, field, offset)                                \
  40 diff --git a/fs/ext4/super.c b/fs/ext4/super.c
  41 index d31aea2..19ae2f9 100644
  42 --- a/fs/ext4/super.c
  43 +++ b/fs/ext4/super.c
  44 @@ -2670,6 +2670,7 @@ EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
  45  EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
  46  EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
  47  EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
  48 +EXT4_RW_ATTR_SBI_BOOL(squelch_errors, s_mount_flags, EXT4_MF_FS_SQUELCH);
  49
  50  static struct attribute *ext4_attrs[] = {
  51         ATTR_LIST(delayed_allocation_blocks),
  52 @@ -2687,6 +2688,7 @@ static struct attribute *ext4_attrs[] = {
  53         ATTR_LIST(max_writeback_mb_bump),
  54         ATTR_LIST(extent_max_zeroout_kb),
  55         ATTR_LIST(trigger_fs_error),
  56 +       ATTR_LIST(squelch_errors),
  57         NULL,
  58  };
  59