ext4: fix BUG when calling ext4_error with locked block group
The mballoc code likes to call ext4_error while it is holding locked
block groups. This can causes a scheduling in atomic context BUG. We
can't just unlock the block group and relock it after/if ext4_error
returns since that might result in race conditions in the case where
the filesystem is set to continue after finding errors.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index a9dd117..2415e2b 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -366,6 +366,44 @@
va_end(args);
}
+void ext4_grp_locked_error(struct super_block *sb, ext4_group_t grp,
+ const char *function, const char *fmt, ...)
+__releases(bitlock)
+__acquires(bitlock)
+{
+ va_list args;
+ struct ext4_super_block *es = EXT4_SB(sb)->s_es;
+
+ va_start(args, fmt);
+ printk(KERN_CRIT "EXT4-fs error (device %s): %s: ", sb->s_id, function);
+ vprintk(fmt, args);
+ printk("\n");
+ 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, es, 0);
+ return;
+ }
+ ext4_unlock_group(sb, grp);
+ ext4_handle_error(sb);
+ /*
+ * We only get here in the ERRORS_RO case; relocking the group
+ * may be dangerous, but nothing bad will happen since the
+ * filesystem will have already been marked read/only and the
+ * journal has been aborted. We return 1 as a hint to callers
+ * who might what to use the return value from
+ * ext4_grp_locked_error() to distinguish beween the
+ * ERRORS_CONT and ERRORS_RO case, and perhaps return more
+ * aggressively from the ext4 function in question, with a
+ * more appropriate error code.
+ */
+ ext4_lock_group(sb, grp);
+ return;
+}
+
+
void ext4_update_dynamic_rev(struct super_block *sb)
{
struct ext4_super_block *es = EXT4_SB(sb)->s_es;
@@ -2868,8 +2906,11 @@
set_buffer_uptodate(sbh);
}
es->s_wtime = cpu_to_le32(get_seconds());
- ext4_free_blocks_count_set(es, ext4_count_free_blocks(sb));
- es->s_free_inodes_count = cpu_to_le32(ext4_count_free_inodes(sb));
+ ext4_free_blocks_count_set(es, percpu_counter_sum_positive(
+ &EXT4_SB(sb)->s_freeblocks_counter));
+ es->s_free_inodes_count = cpu_to_le32(percpu_counter_sum_positive(
+ &EXT4_SB(sb)->s_freeinodes_counter));
+
BUFFER_TRACE(sbh, "marking dirty");
mark_buffer_dirty(sbh);
if (sync) {