From 3934e8ebb7cc6e5f1ade35d586ed3eb79b88eb95 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Thu, 10 Aug 2023 07:48:04 -0700 Subject: xfs: create a big array data structure Create a simple 'big array' data structure for storage of fixed-size metadata records that will be used to reconstruct a btree index. For repair operations, the most important operations are append, iterate, and sort. Earlier implementations of the big array used linked lists and suffered from severe problems -- pinning all records in kernel memory was not a good idea and frequently lead to OOM situations; random access was very inefficient; and record overhead for the lists was unacceptably high at 40-60%. Therefore, the big memory array relies on the 'xfile' abstraction, which creates a memfd file and stores the records in page cache pages. Since the memfd is created in tmpfs, the memory pages can be pushed out to disk if necessary and we have a built-in usage limit of 50% of physical memory. Signed-off-by: Darrick J. Wong Reviewed-by: Kent Overstreet Reviewed-by: Dave Chinner --- fs/xfs/Kconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/xfs/Kconfig') diff --git a/fs/xfs/Kconfig b/fs/xfs/Kconfig index 52e1823241fb..152348b4dece 100644 --- a/fs/xfs/Kconfig +++ b/fs/xfs/Kconfig @@ -128,6 +128,7 @@ config XFS_ONLINE_SCRUB bool "XFS online metadata check support" default n depends on XFS_FS + depends on TMPFS && SHMEM select XFS_DRAIN_INTENTS help If you say Y here you will be able to check metadata on a -- cgit