ext4: add an option to control error handling on file data
If the journal doesn't abort when it gets an IO error in file data
blocks, the file data corruption will spread silently. Because
most of applications and commands do buffered writes without fsync(),
they don't notice the IO error. It's scary for mission critical
systems. On the other hand, if the journal aborts whenever it gets
an IO error in file data blocks, the system will easily become
inoperable. So this patch introduces a filesystem option to
determine whether it aborts the journal or just call printk() when
it gets an IO error in file data.
If you mount an ext4 fs with data_err=abort option, it aborts on file
data write error. If you mount it with data_err=ignore, it doesn't
abort, just call printk(). data_err=ignore is the default.
Here is the corresponding patch of the ext3 version:
http://kerneltrap.org/mailarchive/linux-kernel/2008/9/9/3239374
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt
index 74484e6..eb154ef 100644
--- a/Documentation/filesystems/ext4.txt
+++ b/Documentation/filesystems/ext4.txt
@@ -223,6 +223,11 @@
errors=continue Keep going on a filesystem error.
errors=panic Panic and halt the machine if an error occurs.
+data_err=ignore(*) Just print an error message if an error occurs
+ in a file data buffer in ordered mode.
+data_err=abort Abort the journal if an error occurs in a file
+ data buffer in ordered mode.
+
grpid Give objects the same group ID as their creator.
bsdgroups
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index f46a513..6690a41 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -540,6 +540,8 @@
#define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT 0x1000000 /* Journal Async Commit */
#define EXT4_MOUNT_I_VERSION 0x2000000 /* i_version support */
#define EXT4_MOUNT_DELALLOC 0x8000000 /* Delalloc support */
+#define EXT4_MOUNT_DATA_ERR_ABORT 0x10000000 /* Abort on file data write */
+
/* Compatibility, for having both ext2_fs.h and ext4_fs.h included at once */
#ifndef _LINUX_EXT2_FS_H
#define clear_opt(o, opt) o &= ~EXT4_MOUNT_##opt
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 79bd398..014677b 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -778,6 +778,9 @@
seq_printf(seq, ",inode_readahead_blks=%u",
sbi->s_inode_readahead_blks);
+ if (test_opt(sb, DATA_ERR_ABORT))
+ seq_puts(seq, ",data_err=abort");
+
ext4_show_quota_options(seq, sb);
return 0;
}
@@ -907,6 +910,7 @@
Opt_commit, Opt_journal_update, Opt_journal_inum, Opt_journal_dev,
Opt_journal_checksum, Opt_journal_async_commit,
Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
+ Opt_data_err_abort, Opt_data_err_ignore,
Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
@@ -953,6 +957,8 @@
{Opt_data_journal, "data=journal"},
{Opt_data_ordered, "data=ordered"},
{Opt_data_writeback, "data=writeback"},
+ {Opt_data_err_abort, "data_err=abort"},
+ {Opt_data_err_ignore, "data_err=ignore"},
{Opt_offusrjquota, "usrjquota="},
{Opt_usrjquota, "usrjquota=%s"},
{Opt_offgrpjquota, "grpjquota="},
@@ -1187,6 +1193,12 @@
sbi->s_mount_opt |= data_opt;
}
break;
+ case Opt_data_err_abort:
+ set_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
+ break;
+ case Opt_data_err_ignore:
+ clear_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
+ break;
#ifdef CONFIG_QUOTA
case Opt_usrjquota:
qtype = USRQUOTA;
@@ -2535,6 +2547,10 @@
journal->j_flags |= JBD2_BARRIER;
else
journal->j_flags &= ~JBD2_BARRIER;
+ if (test_opt(sb, DATA_ERR_ABORT))
+ journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
+ else
+ journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
spin_unlock(&journal->j_state_lock);
}
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 849f104..0abe02c 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -684,6 +684,8 @@
printk(KERN_WARNING
"JBD2: Detected IO errors while flushing file data "
"on %s\n", journal->j_devname);
+ if (journal->j_flags & JBD2_ABORT_ON_SYNCDATA_ERR)
+ jbd2_journal_abort(journal, err);
err = 0;
}
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index c9e7d78..d2e91ea 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -967,6 +967,9 @@
#define JBD2_FLUSHED 0x008 /* The journal superblock has been flushed */
#define JBD2_LOADED 0x010 /* The journal superblock has been loaded */
#define JBD2_BARRIER 0x020 /* Use IDE barriers */
+#define JBD2_ABORT_ON_SYNCDATA_ERR 0x040 /* Abort the journal on file
+ * data write error in ordered
+ * mode */
/*
* Function declarations for the journaling transaction and buffer