From ea3271f7196c65ae5d3e1c7b3f733892c017dbd6 Mon Sep 17 00:00:00 2001 From: Chris Down Date: Thu, 6 Aug 2020 23:20:25 -0700 Subject: tmpfs: support 64-bit inums per-sb The default is still set to inode32 for backwards compatibility, but system administrators can opt in to the new 64-bit inode numbers by either: 1. Passing inode64 on the command line when mounting, or 2. Configuring the kernel with CONFIG_TMPFS_INODE64=y The inode64 and inode32 names are used based on existing precedent from XFS. [hughd@google.com: Kconfig fixes] Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2008011928010.13320@eggly.anvils Signed-off-by: Chris Down Signed-off-by: Hugh Dickins Signed-off-by: Andrew Morton Reviewed-by: Amir Goldstein Acked-by: Hugh Dickins Cc: Al Viro Cc: Matthew Wilcox Cc: Jeff Layton Cc: Johannes Weiner Cc: Tejun Heo Link: http://lkml.kernel.org/r/8b23758d0c66b5e2263e08baf9c4b6a7565cbd8f.1594661218.git.chris@chrisdown.name Signed-off-by: Linus Torvalds --- fs/Kconfig | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'fs/Kconfig') diff --git a/fs/Kconfig b/fs/Kconfig index a88aa3af73c1..aa4c12282301 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -201,6 +201,27 @@ config TMPFS_XATTR If unsure, say N. +config TMPFS_INODE64 + bool "Use 64-bit ino_t by default in tmpfs" + depends on TMPFS && 64BIT + default n + help + tmpfs has historically used only inode numbers as wide as an unsigned + int. In some cases this can cause wraparound, potentially resulting + in multiple files with the same inode number on a single device. This + option makes tmpfs use the full width of ino_t by default, without + needing to specify the inode64 option when mounting. + + But if a long-lived tmpfs is to be accessed by 32-bit applications so + ancient that opening a file larger than 2GiB fails with EINVAL, then + the INODE64 config option and inode64 mount option risk operations + failing with EOVERFLOW once 33-bit inode numbers are reached. + + To override this configured default, use the inode32 or inode64 + option when mounting. + + If unsure, say N. + config HUGETLBFS bool "HugeTLB file system support" depends on X86 || IA64 || SPARC64 || (S390 && 64BIT) || \ -- cgit v1.2.3