This is btrfs' equivalent of XFS_IOC_GOINGDOWN or EXT4_IOC_SHUTDOWN,
after entering the emergency shutdown state, all operations will return
error (-EIO), and can not be bring back to normal state until unmount.
We reuse the existing btrfs_handle_fs_error() function, which will mark
the fs read-only and output an error message.
This allows us to handle put_super() callback as usual, as the fs is
already marked as error and RO, thus we need no special handling.
The only extra thing is to set the EMERGENCY_SHUTDOWN flag to reject
future operations with -EIO.
Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
---
fs/btrfs/fs.h | 18 ++++++++++++++++++
fs/btrfs/messages.c | 1 +
2 files changed, 19 insertions(+)
diff --git a/fs/btrfs/fs.h b/fs/btrfs/fs.h
index d90304d4e32c..8cc4468a9894 100644
--- a/fs/btrfs/fs.h
+++ b/fs/btrfs/fs.h
@@ -29,6 +29,7 @@
#include "extent-io-tree.h"
#include "async-thread.h"
#include "block-rsv.h"
+#include "messages.h"
struct inode;
struct super_block;
@@ -120,6 +121,12 @@ enum {
/* No more delayed iput can be queued. */
BTRFS_FS_STATE_NO_DELAYED_IPUT,
+ /*
+ * Emergency shutdown, a step further than trans aborted by rejecting
+ * all operations.
+ */
+ BTRFS_FS_STATE_EMERGENCY_SHUTDOWN,
+
BTRFS_FS_STATE_COUNT
};
@@ -1100,6 +1107,17 @@ static inline void btrfs_wake_unfinished_drop(struct btrfs_fs_info *fs_info)
(unlikely(test_bit(BTRFS_FS_STATE_LOG_CLEANUP_ERROR, \
&(fs_info)->fs_state)))
+static inline bool btrfs_is_shutdown(struct btrfs_fs_info *fs_info)
+{
+ return test_bit(BTRFS_FS_STATE_EMERGENCY_SHUTDOWN, &fs_info->fs_state);
+}
+
+static inline void btrfs_shutdown(struct btrfs_fs_info *fs_info)
+{
+ btrfs_handle_fs_error(fs_info, -EIO, "filesystem emergency shutdown");
+ set_bit(BTRFS_FS_STATE_EMERGENCY_SHUTDOWN, &fs_info->fs_state);
+}
+
/*
* We use folio flag owner_2 to indicate there is an ordered extent with
* unfinished IO.
diff --git a/fs/btrfs/messages.c b/fs/btrfs/messages.c
index 363fd28c0268..2bb4bcb7c2cd 100644
--- a/fs/btrfs/messages.c
+++ b/fs/btrfs/messages.c
@@ -23,6 +23,7 @@ static const char fs_state_chars[] = {
[BTRFS_FS_STATE_NO_DATA_CSUMS] = 'C',
[BTRFS_FS_STATE_SKIP_META_CSUMS] = 'S',
[BTRFS_FS_STATE_LOG_CLEANUP_ERROR] = 'L',
+ [BTRFS_FS_STATE_EMERGENCY_SHUTDOWN] = 'E',
};
static void btrfs_state_to_string(const struct btrfs_fs_info *info, char *buf)
--
2.49.0
