ext4: Save error information to the superblock for analysis

Save number of file system errors, and the time function name, line
number, block number, and inode number of the first and most recent
errors reported on the file system in the superblock.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 61 insertions, 19 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index bcf74b3..a94d3f5 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -307,6 +307,35 @@ void ext4_journal_abort_handle(const char *caller, unsigned int line,
 	jbd2_journal_abort_handle(handle);
 }
 
+static void __save_error_info(struct super_block *sb, const char *func,
+			    unsigned int line)
+{
+	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
+
+	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
+	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
+	es->s_last_error_time = cpu_to_le32(get_seconds());
+	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
+	es->s_last_error_line = cpu_to_le32(line);
+	if (!es->s_first_error_time) {
+		es->s_first_error_time = es->s_last_error_time;
+		strncpy(es->s_first_error_func, func,
+			sizeof(es->s_first_error_func));
+		es->s_first_error_line = cpu_to_le32(line);
+		es->s_first_error_ino = es->s_last_error_ino;
+		es->s_first_error_block = es->s_last_error_block;
+	}
+	es->s_error_count = cpu_to_le32(le32_to_cpu(es->s_error_count) + 1);
+}
+
+static void save_error_info(struct super_block *sb, const char *func,
+			    unsigned int line)
+{
+	__save_error_info(sb, func, line);
+	ext4_commit_super(sb, 1);
+}
+
+
 /* Deal with the reporting of failure conditions on a filesystem such as
  * inconsistencies detected or read IO failures.
  *
@@ -324,11 +353,6 @@ void ext4_journal_abort_handle(const char *caller, unsigned int line,
 
 static void ext4_handle_error(struct super_block *sb)
 {
-	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
-
-	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
-	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
-
 	if (sb->s_flags & MS_RDONLY)
 		return;
 
@@ -343,7 +367,6 @@ static void ext4_handle_error(struct super_block *sb)
 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 		sb->s_flags |= MS_RDONLY;
 	}
-	ext4_commit_super(sb, 1);
 	if (test_opt(sb, ERRORS_PANIC))
 		panic("EXT4-fs (device %s): panic forced after error\n",
 			sb->s_id);
@@ -369,7 +392,11 @@ void ext4_error_inode(struct inode *inode, const char *function,
 		      const char *fmt, ...)
 {
 	va_list args;
+	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 
+	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
+	es->s_last_error_block = cpu_to_le64(block);
+	save_error_info(inode->i_sb, function, line);
 	va_start(args, fmt);
 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: inode #%lu: ",
 	       inode->i_sb->s_id, function, line, inode->i_ino);
@@ -387,9 +414,13 @@ void ext4_error_file(struct file *file, const char *function,
 		     unsigned int line, const char *fmt, ...)
 {
 	va_list args;
+	struct ext4_super_block *es;
 	struct inode *inode = file->f_dentry->d_inode;
 	char pathname[80], *path;
 
+	es = EXT4_SB(inode->i_sb)->s_es;
+	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
+	save_error_info(inode->i_sb, function, line);
 	va_start(args, fmt);
 	path = d_path(&(file->f_path), pathname, sizeof(pathname));
 	if (!path)
@@ -459,6 +490,7 @@ void __ext4_std_error(struct super_block *sb, const char *function,
 	errstr = ext4_decode_error(sb, errno, nbuf);
 	printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 	       sb->s_id, function, line, errstr);
+	save_error_info(sb, function, line);
 
 	ext4_handle_error(sb);
 }
@@ -478,6 +510,7 @@ void __ext4_abort(struct super_block *sb, const char *function,
 {
 	va_list args;
 
+	save_error_info(sb, function, line);
 	va_start(args, fmt);
 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 	       function, line);
@@ -485,18 +518,16 @@ void __ext4_abort(struct super_block *sb, const char *function,
 	printk("\n");
 	va_end(args);
 
+	if ((sb->s_flags & MS_RDONLY) == 0) {
+		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
+		sb->s_flags |= MS_RDONLY;
+		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
+		if (EXT4_SB(sb)->s_journal)
+			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
+		save_error_info(sb, function, line);
+	}
 	if (test_opt(sb, ERRORS_PANIC))
 		panic("EXT4-fs panic from previous error\n");
-
-	if (sb->s_flags & MS_RDONLY)
-		return;
-
-	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
-	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
-	sb->s_flags |= MS_RDONLY;
-	EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
-	if (EXT4_SB(sb)->s_journal)
-		jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 }
 
 void ext4_msg (struct super_block * sb, const char *prefix,
@@ -534,6 +565,9 @@ __acquires(bitlock)
 	va_list args;
 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 
+	es->s_last_error_ino = cpu_to_le32(ino);
+	es->s_last_error_block = cpu_to_le64(block);
+	__save_error_info(sb, function, line);
 	va_start(args, fmt);
 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u",
 	       sb->s_id, function, line, grp);
@@ -546,11 +580,10 @@ __acquires(bitlock)
 	va_end(args);
 
 	if (test_opt(sb, ERRORS_CONT)) {
-		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
-		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 		ext4_commit_super(sb, 0);
 		return;
 	}
+
 	ext4_unlock_group(sb, grp);
 	ext4_handle_error(sb);
 	/*
@@ -3332,8 +3365,17 @@ static int ext4_load_journal(struct super_block *sb,
 
 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
 		err = jbd2_journal_wipe(journal, !really_read_only);
-	if (!err)
+	if (!err) {
+		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
+		if (save)
+			memcpy(save, ((char *) es) +
+			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
 		err = jbd2_journal_load(journal);
+		if (save)
+			memcpy(((char *) es) + EXT4_S_ERR_START,
+			       save, EXT4_S_ERR_LEN);
+		kfree(save);
+	}
 
 	if (err) {
 		ext4_msg(sb, KERN_ERR, "error loading journal");