xfs: Pull EFI/EFD handling out from under the AIL lock
EFI/EFD interactions are protected from races by the AIL lock. They
are the only type of log items that require the the AIL lock to
serialise internal state, so they need to be separated from the AIL
lock before we can do bulk insert operations on the AIL.
To acheive this, convert the counter of the number of extents in the
EFI to an atomic so it can be safely manipulated by EFD processing
without locks. Also, convert the EFI state flag manipulations to use
atomic bit operations so no locks are needed to record state
changes. Finally, use the state bits to determine when it is safe to
free the EFI and clean up the code to do this neatly.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/xfs/xfs_extfree_item.h b/fs/xfs/xfs_extfree_item.h
index f7834ec..375f68e 100644
--- a/fs/xfs/xfs_extfree_item.h
+++ b/fs/xfs/xfs_extfree_item.h
@@ -111,10 +111,10 @@
#define XFS_EFI_MAX_FAST_EXTENTS 16
/*
- * Define EFI flags.
+ * Define EFI flag bits. Manipulated by set/clear/test_bit operators.
*/
-#define XFS_EFI_RECOVERED 0x1
-#define XFS_EFI_COMMITTED 0x2
+#define XFS_EFI_RECOVERED 1
+#define XFS_EFI_COMMITTED 2
/*
* This is the "extent free intention" log item. It is used
@@ -124,8 +124,8 @@
*/
typedef struct xfs_efi_log_item {
xfs_log_item_t efi_item;
- uint efi_flags; /* misc flags */
- uint efi_next_extent;
+ atomic_t efi_next_extent;
+ unsigned long efi_flags; /* misc flags */
xfs_efi_log_format_t efi_format;
} xfs_efi_log_item_t;
