Make it easy to test whether or not the error handling subsystem in
ext4 is working correctly. This allows us to simulate an ext4_error()
by echoing a string to /sys/fs/ext4/<dev>/trigger_fs_error.
Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>
Cc: ksumrall@xxxxxxxxxx
---
fs/ext4/ext4.h | 1 +
fs/ext4/super.c | 20 ++++++++++++++++++++
2 files changed, 21 insertions(+)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 511011a..decc15d 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1197,6 +1197,7 @@ struct ext4_sb_info {
struct proc_dir_entry *s_proc;
struct kobject s_kobj;
struct completion s_kobj_unregister;
+ struct super_block *s_sb;
/* Journaling */
struct journal_s *s_journal;
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 628cfcd..9f1ae6b 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2473,6 +2473,23 @@ static ssize_t sbi_ui_store(struct ext4_attr *a,
return count;
}
+static ssize_t trigger_test_error(struct ext4_attr *a,
+ struct ext4_sb_info *sbi,
+ const char *buf, size_t count)
+{
+ int len = count;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (len && buf[len-1] == '\n')
+ len--;
+
+ if (len)
+ ext4_error(sbi->s_sb, "%.*s", len, buf);
+ return count;
+}
+
#define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
static struct ext4_attr ext4_attr_##_name = { \
.attr = {.name = __stringify(_name), .mode = _mode }, \
@@ -2503,6 +2520,7 @@ EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
+EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
static struct attribute *ext4_attrs[] = {
ATTR_LIST(delayed_allocation_blocks),
@@ -2517,6 +2535,7 @@ static struct attribute *ext4_attrs[] = {
ATTR_LIST(mb_stream_req),
ATTR_LIST(mb_group_prealloc),
ATTR_LIST(max_writeback_mb_bump),
+ ATTR_LIST(trigger_fs_error),
NULL,
};
@@ -3087,6 +3106,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
goto out_free_orig;
}
sb->s_fs_info = sbi;
+ sbi->s_sb = sb;
sbi->s_mount_opt = 0;
sbi->s_resuid = EXT4_DEF_RESUID;
sbi->s_resgid = EXT4_DEF_RESGID;
--
1.7.10.2.552.gaa3bb87
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