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authorJan Kara <jack@suse.cz>2019-03-14 23:46:05 -0400
committerTheodore Ts'o <tytso@mit.edu>2019-03-14 23:46:05 -0400
commit1dc1097ff60e4105216da7cd0aa99032b039a994 (patch)
tree4fc2321b1a4cae5ed6f34228cd2c04bf217efd32 /fs/ext4
parent372a03e01853f860560eade508794dd274e9b390 (diff)
downloadlinux-1dc1097ff60e4105216da7cd0aa99032b039a994.tar.bz2
ext4: avoid panic during forced reboot
When admin calls "reboot -f" - i.e., does a hard system reboot by directly calling reboot(2) - ext4 filesystem mounted with errors=panic can panic the system. This happens because the underlying device gets disabled without unmounting the filesystem and thus some syscall running in parallel to reboot(2) can result in the filesystem getting IO errors. This is somewhat surprising to the users so try improve the behavior by switching to errors=remount-ro behavior when the system is running reboot(2). Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
-rw-r--r--fs/ext4/super.c16
1 files changed, 13 insertions, 3 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 6e4cac646345..1a5729d8f9ec 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -430,6 +430,12 @@ static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
spin_unlock(&sbi->s_md_lock);
}
+static bool system_going_down(void)
+{
+ return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
+ || system_state == SYSTEM_RESTART;
+}
+
/* Deal with the reporting of failure conditions on a filesystem such as
* inconsistencies detected or read IO failures.
*
@@ -460,7 +466,12 @@ static void ext4_handle_error(struct super_block *sb)
if (journal)
jbd2_journal_abort(journal, -EIO);
}
- if (test_opt(sb, ERRORS_RO)) {
+ /*
+ * We force ERRORS_RO behavior when system is rebooting. Otherwise we
+ * could panic during 'reboot -f' as the underlying device got already
+ * disabled.
+ */
+ if (test_opt(sb, ERRORS_RO) || system_going_down()) {
ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
/*
* Make sure updated value of ->s_mount_flags will be visible
@@ -468,8 +479,7 @@ static void ext4_handle_error(struct super_block *sb)
*/
smp_wmb();
sb->s_flags |= SB_RDONLY;
- }
- if (test_opt(sb, ERRORS_PANIC)) {
+ } else if (test_opt(sb, ERRORS_PANIC)) {
if (EXT4_SB(sb)->s_journal &&
!(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
return;